SECTION I. Of the Component Parts.

I Purposely pass over the various De­finitions of a Part, as being of no great Use; and for the same Reason I will not trouble the Reader with the several Divisions which Anato­mists make of the Parts of the Humane Body. All the Parts are made up of Fibres. It is sufficient to know that all the Parts are made up of Threads or Fi­bres, of which there be different Kinds; [Page 2]for there are some soft and flexible, and these are either hollow like small Pipes, or spongious and full of little cells, as the nervous and fleshy Fibres; others there are more Solid, flexible, but with a na­tural Elasticity or Spring, as the Mem­branous and Cartilaginous Fibres: And a Third sort are hard and inflexible as the Fibres of the Bones. And of all these, some are very sensible, and others are destitute of all sense; some so very small as not to be easily perceived, and others on the contrary so big as to be plainly seen.

Now the several Parts of the Body are formed by the various texture and diffe­rent Combination of some or more of these Fibres; and therefore tho' com­monly the Bones, Nerves, Ligaments, Cartilages, Veins and Arteries are reck­oned Similar Parts, No Similar Parts. that is Parts made up of one sort of Fibres, yet all of them have either more or less of different sorts of Fibres, and may be called Dissimilar Parts, as well as the Lungs or Stomach.

SECT. II. Of the External Parts.

The Division of the Body.THE Body is divided into four Prin­cipal Parts; which are, the Head, the Thorax, the Abdomen and the Ex­tremities, viz. the Arms and Legs.

The external Parts of the Head.The External Parts of the Head or upper Cavity are, the Face, and the Calva or Hairy Scalp. The Parts of the Face are, the Brow, the Ears, the Eyes, the Cheeks, the Nose, the Philtrum and its sides, the Mustaches, the Lips, the Mouth, and the Chin. The Parts of the Hairy Scalp are, the Sinciput or Forehead, un­der which lieth the Os frontis; it reaches to the Coronal Suture. The Occiput or Hind-head, under which lies the Os Oc­cipitis, it reaches from the angle of the Sutura Lambdoidalis to the first Vertebra of the Neck. The Vertex or Crown of the Head, under which is the Sutura Sa­gittalis, and part of the two Parietal Bones. The Temples or the sides of the hairy Scalp, under which are the Crota­phite Muscles, the Ossa Petrosa; they reach to the Suturae Squammosae.

Of the Ear.The External Ear is divided into two Parts, of which the upper is called Pinna, or the Wing; the lower Fibra or Lobe. The Parts of the Pinna are the Helix, which is the outward circle or border of the Ear; the Anti-helix which is the Semicircle within the other, and almost parallel to it: The lower end of this Semicircle makes a little Prominence, which is called Antitragus; there is a­nother Prominence just opposite to it, which is called Tragus, because of some Hair that is upon it. The Cavity made [Page 4]by the Anti-helix is called Concha; the hole in the middle of the Ear, which goes to the Tympanum, is called Alve­arium.

Of the Eyes.The External Parts of the Eyes are, the Supercilia or Eye-brows, the Can­thus Internus or the great Angle, where the Caruncula Lachrymalis is, the Can­thus Externus or the little Angle, which is the furthest from the Nose, the Pal­pebrae or the upper and lower Eye-lids, which cover the Eyes; the Cilia, which are little Cartilages on the edge of the Eye-lids; the Puncta Lachrymalia, which are two little holes near the big Angle of the Eye; there are Hairs upon the Cilia in form of a Pallisado. The Or­bite is a Cavity made by the Bones, in which the Globe of the Eye is contained, with its six Muscles; the Tunica Con­junctiva, which is the white of the Eye; the Cornea, the Iris, in the middle of which is Pupilla or Pupil, or Sight.

Of the Nose, Lips, &c.The Nose has its Spina or ridge. It reaches from the Brow to the Cartilage Acromion. The Acromion reaches from the end of the Spine to the Globulus or tip of the Nose. The Nostrils are the Passages into the Nose. The Alae or wings of the Nose are the sides of the Nostrils. The Columna is the little fleshy Portion, which reaches from the tip of the Nose to the Philtrum; it di­vides [Page 5]the Nostrils. The Philtrum is the little Canal, which comes from the lower part of the Nose upon the upper Lip. The Cheeks reach from the lower part of the Eyes to the Lips. The Mentum or Chin, is the fore part of the Lower-Jaw. The Lower-Jaw reaches from the two Ears to the Chin inclusively. The Lips are the Musculous Flesh at the entry of the Mouth; their External Part is called Prolabium, and that, which is tinctured red, Prostomia. The Gums are the Flesh which cover the lower part of the Teeth.

Of the Neck.The Neck reaches from the Head to the Claviculae or Chanel Bones. Its Parts are the Throat, which is its forepart, along which descends the Trachea Ar­teria or Wind-pipe, and the Oesophagus or Gullet. The Pomum Adami is the eminence which appears in the upper Part of the Throat. The Cervix is the hind-part of the Neck; its upper part is called Lophia, the middle Fossa, and the lower Epomis. The Parotides make the upper and lateral Part of the Neck, Terthra the middle, and Paralophia the lower. The Claviculae or Chanel-bones, are the two little Bones situated at the Basis of the Neck above the Breast.

Of the Exter­nal Parts of the Thorax [...] middle CavityAll that lies betwixt the Claviculae or Chanel Bones, and the Diaphragma or Midriff is taken for the Thorax, that is [Page 6]to say, from the Basis of the Neck to the last of the false Ribs inclusively. The forepart of the Thorax is called the Breast; it is composed of the Claviculae and the Sternum or Breast Bone which is in the middle; it begins at the Clavi­culae and terminates in the Cartilago Xi­phoides or Sword like Cartilage. Under the Sternum lies the Mediastinum, and the Heart in its Pericardium. The Mammae or Dugs are two round Tumours, which appear upon the forepart of the Chest, under which are situated part of the Ribs, the Pleura and the Lungs: There stands upon their Centre a little Protuberance called Papilla, or Nipple, which is encompassed with a reddish circle called Areola. The hinder Part of the Thorax is called the Back, com­posed of 12 Vertebrae or Joints, and two Scapulae or Shoulder Blades, which are the two upper Parts of the Back on the sides of the Vertebrae. The lateral Parts of the Thorax are called▪ Peristerna.

Of the Exter­nal Parts of [...]he Abdomen, [...] lower Belly.The Lower Belly extendeth from the Cartilago Xiphoides, to the Os Pubis; the forepart is called Abdomen, and the hind­part the Backside. The Abdomen is di­vided into upper, middle, and lower Parts. The upper reaches from the Car­tilago Xiphoides till within two Fingers breadth above the Navel; it is called Epigastrium, and its two sides Hypochon­dria: [Page 7]it covers a Part of the Liver and Stomach; the right covers the greatest Part of the Liver: the left the Spleen, part of the Stomach, and Colon. The middle Part of the Abdomen, is only two Fingers breadth above, and as much be­low the Navel; it is called Regio Ʋmbi­licalis; its middle is called Ʋmbilicus or Navel, thorow which passes the Umbi­lical Vein, two Arteries, and the Ʋra­chus. Under the middle of this Region lies all the Intestinum Jejunum, and Part of the Ileum. The sides of this Region are called by Glisson, Epicolicae, because they cover the Colon: Under the right is contained the right Kidney, part of the Colon, and Jejunum: under the left is contained the left Kidney, with part of the Colon and Jejunum. The lower Part of the Abdomen reaches from the Umbi­lical Region to the lower Part of the Os Pubis; it is called the Hypogastrium; it covers the Bladder, Womb, and the Rectum or strait Gut. The lower Part of the Hypogastrium is called Pecten or Regio Pubis; its sides Inguina or Groins. The sides of the Hypogastrium are called Ilia, either because they contain almost all the Gut Ileum, or because they ter­minate at the lower Part of the Os Ilium. The Inguina or Groins are be­low the Ilia, where there is a Part of the Muscle Cremaster, with the Produ­ctions [Page 8]of the Peritonaeum. The hind Part of the Abdomen is called the Backside; it reaches from the last Ribs to the ex­tremity of the Os Sacrum. It is divided into two Parts, the upper is called the Small of the Back, its sides the Loins; the middle of the lower Part is called Radius; at its lower end is the Anus, and its sides the Nates or Buttocks. The Perinaeum is the space between the Anus and the Scrotum or Vulva in Wo­men.

Of the Exter­nal Parts of Generation in Men.Those that are Proper to Men, are the Yard and the Scrotum. The Extremity of the Yard is called the Glans: the Praeputium or Fore-Skin is the Skin dou­bled which covers the Glans like a Hood. The Fraenum or Bridle is a little whitish coloured Ligament, which ties the Fore-Skin and the Glans together beneath. The edge of the Glans where the Praepu­tium begins, is called Corona or Crown. The Ʋrethra is the Canal which runs along the under side of the Yard, thorow which the Seed and the Urine pass. The Rapha or Ridge is a Line, which running along the under side of the Yard, divides the Scrotum and Perinaeum in two; its length is from the Fraenum to the Anus. It is not ordinarily cut in the Operation for the Stone; first, be­cause it's harder than any other Part of the Skin there, and then you cut upon [Page 9]the Interstices of two Muscles, which make the reunion the difficulter. The Scrotum is the Purse which contains the [...]wo Testicles.

Of the Exter­nal Parts of Generation in Women.The External Parts of Generation proper to Women, are the Vulva or great Chink situated below the Os Pubis, and [...]overed with Hair; above this, there is [...] little Swelling made by some Fat under [...]he Skin, which is called Mons Veneris. The Labia or Lips of the great Chink are only the Skin swelled by some fat underneath; these being a little sepa­rated, there appear the Nymphae, one on each side of the Chink; they are two small pieces of Flesh, resembling the Membranes that hang under the Throats of Pullets. In the middle and upper Part of the great Chink within, is the Clitoris, which is a small, round, and long body covered with a little hood of the Skin called Praeputium. At the further end of the Clitoris there is a little hole, which is the Orifice of the Neck of the Bladder, and below that are the Glandulae Myrti­formes, situated in the fossa magna, or Navicularis, which is the lower Part of the Vulva, where there is a Ligament called the Fork, which is torn in the first Birth. The bottom of the Vul­va is the orifice of the Neck of the Womb.

Of the Exter­nal Parts of the Arms, Fore-arms and Hands.The Arm is from the Joint of the Shoulder to the Elbow, which is the place where we bend our Arm. The Fore-arm is from the Elbow to the Wrist or Carpus, which is the Articu­lation where the Fore-arm ends. The Hand is all that which is betwixt the Wrist and the ends of the Fingers. The Parts of the Hand are the Metacarpus, which is from the Wrist to the root of the Fingers; the outside, which is the Back of the Hand, and the inside, which is the Palm of the Hand; the Mons Ve­neris is the fleshy Part of the Hand nigh the Thumb; the Finger next the Thumb is called the Index or Fore-finger, then follows the middle, the Ring-finger, and the little one. Upon the Extre­mities of the Fingers are the Nails, the white Spot which is at the root of the Nails is called Onyx.

[...]f the Exter­ [...]al Parts of [...]e Thigh and [...]eg.The Thigh is from the Haunch to that Joint of which the Fore-part is called the Knee; the Back-part the Ham.

The Leg is from the Knee to the Tarsus; its Fore-part is called the Shin, and the Back-part the Calf of the Leg; the Eminences which are at its Extre­mity nigh the Tarsus, are called the An­kles of the Foot, they are two, the outer and inner; the Tarsus is from the An­kles to the Metatarsus, or breadth of [Page 11]the Foot, which goes to the root of the Toes; the upper part of the Foot is called Instep, the under Part the Sole of the Foot; the Toes are five in number, with their Nails.

SECT. III. Of the Common Parts or Teguments of the Epiderma or Cuticula.

THE first of the Common Parts is the Cuticula or Scarfskin, called by the Greeks Epiderma. It is a thin, fine, and close Membrane, a little Diaphanous, and without sense; it covers all the true Skin to which it is adherent: It is for­med in the Womb, and grows in Pro­portion to the rest of the Parts; yet it has neither Veins, Nerves, nor Arteries. It is pierced by an infinite number of holes, for the passage of Sweat and in­sensible Transpiration: Its figure, length, and breadth is equal to that of the Skin: Its use is to cover the Skin, to make it smooth and equal, to be a Medium to the sense of touching, which other­wise could not be performed without Pain, it the impressions of the Objects were made immediarely upon the Fi­bres and Nerves of the Skin. The thicker and harder it is, the duller is the sense of touching, and the transpi­ration the less: the thinner, clearer, and [Page 12]smoother it is, 'tis so much the more beautiful. Leuwenhoeck thinks that the Cuticula is nothing but the Excretory Channels of the Miliary Glands of the Skin, as the Scales are in Fishes.

SECT. IV. Of the Skin.

The Parts of the Skin.WE remark in the Skin, the Scarfskin being raised, Three Parts. The First is an infinite Number of Papille Pyramidales; they are the Ends of all the Nerves of the Skin, each of which are enclosed in two or three Covers of a Pyramidale Figure, and these Covers are each above another. They may be easily seen and separated in the Skin of an Ele­phant, and in the Skin of the Feet of several other Animals. Between these Papillae are an infinite number of holes, which are nothing but the Orifices of the excretory Vessels of the Miliary Glands underneath. The Second Part is a web of nervous Fibres and other Vessels differently interwoven, it is al­ways covered with a mucous Substance, which serves to support and moisten the Papillae Pyramidales, and it is the Paren­chima or that part of the Skin that the Parchment is made of. The Third Part is an infinite number of Miliary Glands, about which there is much fat; they [Page 13] [...] under the other two Parts, they se­ [...]te the matter of Sweat and insen­ [...] transpiration. Each Gland receives [...]erve and Artery, and sends out a [...] and excretory Vessel, which last [...]es thorow the other two Parts to the [...]icula, for the discharging the Body [...]his Matter, and for the moistening the [...]icula and the Papillae Pyramidales, that [...] may not be dry, which would very [...]h hurt the sense of touching. Upon [...] surface of the Skin there are many [...]allel Lines, which are cut by as many [...]allel ones. These Intersections make [...]es of a Rhomboidale figure; and [...]on the Ends of the Fingers, these [...]es are Spiral. There is a Pore, [...]h a hair, in the most part of the [...]ersections; the more there are of [...]se Lines, and the deeper they are, [...] rougher and the more wrinkled is [...] Skin. The thickness of the Skin. The Skin is six times thicker [...] the Scarfskin: And in the Sole of [...] Foot it is much thicker than in the [...]e, Hands, and other Parts. In the [...]mmer it is thinner and softer, because [...] Pores are wider. In the Winter it is [...]re compact and harder, because the [...]res are more close; therefore the hairs [...] Beasts stick faster, and Furs made of [...]em, are better in that Season. In some [...]e Skin is white, in others black and [...]uny, which probably comes from the [Page 14]different colours of the Mucosity which covers the Parenchima of the Skin; [...] the Fibres of the Skin in all are white and there is little or no difference in the colour of different Bloods. The Skin has communication with all the rest of the Body, by the Veins, Nerves, Arteries, and Lymphaticks, which it receives from all Parts of the Body in abundance. Its Use is to cover and wrap up all the Parts of the Body, The use of the Skin. to be the Organ of the sense of touching, and the emunctory of the whole Body.

SECT. V. Of the Hair.

THE Hair may justly be reckoned one of the common Teguments of the Bo­dy, not only for its Use, but also because it is to be found upon all the Parts of the Body, except the Soles of the Feet and Palms of the Hands. It grows long­est upon the Head, Beard, in the Arm-Pits, and about the Privities. When we examine the Hairs with a Microscope, we find that they have a great resem­blance with Plants: for they have each a round bulbous root which lies pretty deep in the Skin, and which draws their Nourishment from the surrounding Hu­mours, and therefore they grow after Death. In some places 'tis apparent [Page 15] [...]hey receive a small twig of a Nerve. The Hairs themselves appear hollow, which is also confirmed by the Plica Po­ [...]nica, in which Distemper the Blood [...]rops from their Extremities; they are generally of a triangular figure, and [...]heir different colours depend much up­on the different temperaments and qua­ [...]ity of the Humours that nourish them. The use of the Hairs is for a Covering and Ornament to the Body; whatsoever the efficient Cause may be why a Man has a Beard and a Woman [...]one, it is certain, the final Cause is for the distinguishing the Male from the Female Sex, which otherwise could hard­ly be known, if both were dress'd in the [...]ame Habit.

SECT. VI. Of the Fat.

THE Fat which is another of the common Teguments of the Body, is an oily and sulphureous Substance, contained in a number of little mem­branous Cells, which being look'd upon with a Microscope, resemble the Cells of Honey-combs, only they are not so re­gular, being they are somewhat flat, and almost of an oval figure. The Mem­brane of which these Cells are composed is very thin and transparent, and seems [Page 16]to be only a continuation or produ­ction of the Membrana Adiposa, to which it closely adheres: This Mem­brana Adiposa lies under these Cells, and in a manner is their basis and support. From this Membrane arise a great number of Veins, Arteries, and Nerver which divide into an infinite number of branches, which terminate in the cellu [...] adiposae.

The Vessels of the Fat. Malpighius has discovered a Net of small Vessels, which he calls Ductus adi­posi, because they are full of Fat; these he supposes, bring the Fat into the Cells; but he could never discover from whence they take their rise. There are also a number of little Glands, which are ac­companied with Lymphatick Vessels, which carry back any Serosity that is superfluous. The Fat is to be found immediately under the Skin, in all the Parts of the Body, except in the Fore­head, Eye-lids, Lips, upper part of the Ear, Yard, and Scrotum; but in all the other Parts of the Body there is more or less; there is much about the Heart, the Kidneys, the Intestines, the Thighs, the Glands and the Joints. There are two sorts of Fat, Two sorts of Fat. one white, or rather yellow, soft, and lax, which is easily melted, called Pinguedo; Another white, firm, brittle, and which is not easily melted, called Sevum or Tallow. Some [Page 17]reckon the Marrow of the Bones for a [...]hird sort of Fat.

The Ʋse of the Fat.The chief Use of the Fat is to hinder [...] too great Exaltation of the Salts: for there is nothing which sweetens so much [...]he Acrimony of exalted Salts, as greasy and oily Substances; therefore it is found almost thorow all the Body, that it may be taken up by the Veins, to blunt and sweeten the too great sharpness and Acrimony of the Salts, which are in the Blood. The Fat which is about the Glands has the same use, in respect of the Lymphae; and that which is about the Kidneys, may serve to preserve their Bason-against the Salts of the Urine. The Fat serves sometimes for the nou­rishment of the Body, and for the en­tertaining of the Natural Heat. Hence it is that the Dormouse and other Crea­tures live, during a whole Winter, with­out any other Food. It serves also to moisten and souple the Parts, for faci­litating their Motion; to fill up the In­terstices of the Parts, that the Skin may be smooth and beautiful; to defend the Body against external Cold; and in fine, to hinder too great a dissipation of the Spirits.

SECT. VII. Of the Membrana Adiposa, Carnosa, Com­munis, and Propria Musculorum.

What a Mem­brane is.A Membrane is a web of several sor [...] of Fibres interwoven, for the co­vering and wraping up of some Part [...] Their membranous Fibres give them [...] Elasticity, whereby they can contra [...] and closely grasp the Parts they con­tain, and their nervous Fibres give the [...] an exquisite sense, which is the cause [...] their contraction; therefore they c [...] scarcely suffer the sharpness of Medi­cines, and they are difficultly unit [...] where there is a solution of continuity or loss of their Substance. In their te [...] ­ture there are a number of small Glands which separate an humour fit for moi­stening the Parts which they contain. Those that cover the solid Parts, A distinction of Membranes. are properly called Membranes; and they have their particular Names, as the Pe­ritonaeum, which wraps up all that is contained in the Abdomen; the Pleura▪ that which is in the Thorax; the Peri­ostium the Bones, and the Pericardium the Heart. Those which form the Coats of Vessels, and which contain the Hu­mours, as those of the Veins, Arteries, Stomach, Bladder, Intestines, Testicles, &c. are called Tunicles or Coats: And those [Page 19]which cover and embrace the Brain, as [...]e Dura and Pia Mater, are called Me­ [...]ages. Of all these Kinds of Mem­ [...]anes, some are thin, and some are [...]ick; and the same Membrane is thick [...] some places, and thin in other pla­ [...]s, as in the Membrana Adiposa, which [...] thicker in the Neck than in any o­ther Part of the Body. The Ʋse of the Membranes. The Use of the [...]embranes is to cover and wrap up the [...]arts; to strengthen them; to save them from External Injuries; to pre­ [...]rve the Natural Heat; to join one [...]art to another; to sustain small Ves­sels, and the Nerves which run thorow their Duplicatures; to stop the return­ing of the Humours in their Vessels, as [...]he Valves stop the returning of the Blood in the Veins and Heart; of the Chyle in the Lacteals and Thoracick Duct; and of the Lympha in the Lym­phatick Vessels.

The Membra­na, Adiposa, and Carnosa.The Membrana Adiposa, which is said to be the basis of the Cellulae Adiposae is double, and may be divided into two Parts, the one is External, thorow which there are a number of little Cells, full of Fat; the other is Internal, which Anatomists have mistaken for the Mem­brana Carnosa, because it has a greater number of blood Vessels.

Of the Mem. Com. Musc.Anatomists do generally assert, that there is a Membrana Communis Musculo­rum, [Page 20]being led into that Mistake by [...] Aponeurosis of several Muscles; where [...] upon stricter Observation, there is no su [...] thing to be found. Of the Mem­brana Propria Musculorum. The Membrana Pro­pria Musculorum, is that which cov [...] immediately all, and every one of the [...] ­bres of a Muscle, and is closely attach [...] to them. Of the Mem­brana Com­munis Vascu­lorum. There is another called Mem­brana Communis Vasculorum, which is thin Membrane, and accompanies almo [...] all the Vessels of the Body. All the [...] Membranes receive Veins, Arteries, a [...] Nerves from the Parts which are near [...] to them.

SECT. I. Of the Muscles in General.

The Definition of a Muscle.A Muscle is a bundle of fleshy and often tendinous Fibres, of which all in the same Plane are Parallel to one another, and they are all enclosed by one proper Membrane. Of the fleshy Fibres. The fleshy Fibres compose that Part, which is cal­led the Body or Belly of the Muscle; they are red, lax, and spongious, con­taining [Page 21]a number of small Cavities: [...]y are tied together by a number of [...]ll and short Threads, which go from [...]re to Fibre, called Membranous Fi­ [...]s. Of the tendi­nous Fibres. The Tendinous Fibres compose [...] two Extremities; they are called [...] Head and Tail, or the two Ten­ [...]ns of the Muscle; they are white, [...]d, compact, and closely bound to­ [...]ther, that which makes them lefs [...]an the body of the Muscles. In eve­ [...] Tendon, there are as many tendinous [...]ores, as there are fleshy Fibres in the [...]dy of the Muscle; so that every fleshy [...]bre answers, at both ends, to a tendi­nous Fibre, to which they are always [...]n'd obliquely, making equal and al­ [...]rnative Angles. The Surface of the [...]elly of the Muscles resembles a Rhom­ [...]ides or Lozenge, to whose opposite [...]des the Tendons are joined at oblique [...]nd alternative Angles.

The Division of Muscles.Muscles are either Simple or Com­posed; the Simple have all their Fibres [...]arallel, and in the same Direction. The [...]omposed have the fleshy Fibres of se­veral Planes crossing one another, or of [...]ifferent Directions; and they may be divided into as many simple Muscles as there are Planes, whose Fibres have dif­ferent Directions. The Strength of a Muscle consists in the Union of many Fibres. The Motion of a Muscle is [Page 22]always towards its Centre. The Ten­dons are sometimes double and triple as the Biceps and Triceps. Sometime several Muscles join in one Tendon as the tendo Achillis. Sometimes o [...] Muscle has two Bellies, as the Dig [...] ­stricus.

We find also Muscles without Ten­dons, as the Quadratus of the Fore-a [...] and several of the Face, Tongue, a [...] Lower Jaw; and they are only inserte [...] into the Periostium; whereas those tha [...] have Tendons are inserted into the body of the Bone. There are others which have only Tendons at one end, as may be seen in the Myology. This makes [...] suspect that Tendons are only for th [...] conveniency of having a great number of Fibres inserted about a small Bo [...] Those who would have a more parti­cular Description of the Muscles may consult Steno, where they will see how [...] Muscle may swell without the addition of any New matter, only by the change of their Angles.

The Muscles have Nerves, Veins, Ar­teries, and Lymphaticks, as other Parts [...] their use is to bend and extend, and to perform all the motions of the Parts.

SECT. II. Of the Muscles of the Lower Belly.

[...]Aving raised the Skin and Fat, the the Muscles of the Lower Belly ap­ [...]ar, which are Five Pair in Number; [...]e first of which that presents it self, is [...]e Obliquus externus or Descendens; Obliquus en­ternus. it [...]es its Origination from the two last [...]ue, and the five false Ribs, by five or [...] Digitations, betwixt the teeth of the [...]ratus major, from the upper and fore­ [...]rt of the Spine of the Ilium; its Fi­ [...]es, descending obliquely, are inserted [...] along the Linea alba under the Mus­ [...]li recti; and to the forepart of the Os [...]ubis. It has a large Aponeurosis, which [...]vers both it's self and the Musculi [...]cti. The Linea alba is a Line which [...]ches betwixt the Cartilago Xiphoides [...]d the Os Pubis, made by the union of [...]e Tendons of the Oblique and Trans­ [...]rse Muscles, dividing the Abdomen in [...]o in the middle. This Muscle re­ [...]ives a twig of a Nerve from the Inter­ [...]stals at each of its Digitations.

Obliquus in­ternus.The second Pair is the Obliquus ascen­ [...]ens or Internus, whose Fibres are dispo­ [...]d in a contrary manner, crossing the [...]ormer obliquely; they arise with a [...]rge and fleshy beginning, from the Circumference of the Ilium, from the [Page 24] Os Pubis: Above they are fixed to the Cartilaginous Part of the false Rib [...] and they are inserted all along the Linea alba.

The third Pair is the Transversalis it lies under the two former, Transversalis. it arise from the Cartilago Xiphoides, from the Extremities of the false Ribs; from the transverse Apophises of the Vertebrae [...] the Loins; it [...]s fixed to the inner side [...] the Spine of the Ilium, and is inserted [...] the Os Pubis, and Linea alba.

These three Muscles unite their Ten­dons as they approach the Linea alba they are pierced in the middle of the Linea alba, for the Passage of the Um­bilical Vessels. They are also pierce [...] above the Os Pubis, for the Passage of the Spermatick Vessels in Men, and the round Ligaments of the Womb in Wo­men. These holes are not opposed to one another: that which is in the Trans­versal is highest, that in the Obliquus ascendens is a little lower, and that i [...] the Obliquus descendens lowest. It is thi [...] last which is only cut in the Operation of the Bubonocele; it has a fine and thi [...] Membrane that closes exactly its ring [...] hole, through which the Vessels pass.

The fourth Pair which is covered with the Aponeurosis of the Obliqui, Rectus. is the Musculus Rectus; it arises from the Ster­num, the Extremity of the last true [Page 25]Rib, from the Cartilago Xiphoides, and goes straight down the middle of the Abdomen to be inserted in the Os Pubis. This Muscle has three or four Inner­vations, which when the Muscle act­eth, serve to render the compression equal, which otherwise would be all in the middle. It has Veins and Arteries which creep on its inside, from the Mammillary and the Epigastrick Vessels, which are supposed to have Commu­nication, that the Blood may return by the Mammillary Veins, when the Passage is stopt by the Epigastrick, which are compressed in Women big with Child.

The fifth Pair is the Pyramidalis, Pyramidalis. so called because of their Figure: they rise with a fleshy beginning, from the outer, and upper part of the Os Pubis, and growing narrower and nar­rower, are inserted into the Linea alba, sometimes near to the Navel. Some­times one, and sometimes both of these Muscles are wanting. The use of these Muscles. The Use of all the Muscles of the Lower Belly is to compress all the Parts that it contains, for the filtration and distribution of the Chyle, for the expulsion of the Excrements, all of them help the ex­piration by making the Diaphragma mount up; and the Obliqui help to pull down the Ribs for the contracting [Page 26]of the Thorax; they help to bend the Trunk forwards. By the admirable Contrivance of their Fibres decussating one another, every point of the Lower Belly is sufficiently compress'd, so [...] that the Intestines can slip no where from the Compression.

SECT. III. Of the Peritonaeum.

Its Descrip­tion.AFter the Muscles of the Lower Belly are raised, comes the Peritonaum It is a thin and soft Membrane, which encloses all the Bowels contained in the Lower Belly, covering all the in­side of its Cavity. Its external Super­ficies is unequal where it adheres to the transverse Muscles. The Internal is very smooth and polish'd. It has a number of small Glands that separate a Liquor, which supples the Intestines, and facilitates their motion. When these Glands are obstructed, the Pe­ritonaeum grows thick, as may be seen in several Dropsies.

The upper Part of this Membrane covers the Midriff, to which it closely adheres, the forepart of it sticks to the Transverse Muscles, and Linea alba; the lower part of it to the Os Pubis, and the back part of it to the Os Sa­crum and Vertebrae of the Loins. 'Tis a [Page 27]double Membrane, and contains in its Duplicatures the Umbilical Vessels, the Bladder, the Ureters, the Kidneys, and Spermatick Vessels, to all which it gives a Membrane, as also to the Li­ver, Spleen, Stomach, Intestines, and Womb.

Its Produ­ctions.Its external Membrane has two Pro­ductions, like to two Sheaths, which pass thorow the rings of the oblique and transverse Muscles in the Groin, for the passage of the Spermatick Vessels in Men, and for the round Ligaments of the Womb in Women. These Productions being come to the Testicles in Men, dilate and form the Tunica Vaginalis.

Its Vessels.The Peritoraum has Veins and Arte­ries from the Phraenic [...]e, from the Mam­millary, the Epigastnick, and often from the Spermaticks. Its Nerves are of those which are distributed in the Muscles of the Abdoman. By the ela­sticity of its Fibres, it easily dilates and contracts in respiration and con­ception. If it breaks, it causes a Rup­ture either in the Groin or Navel. Its Use is to contain the Bowels of the Abdomen, and to give each of them an outer coat.

SECT. IV. Of the Navel.

THE Navel is a knot in the middle of the Abdomen, made by the Union of the Umbilical Vessels, which are cut after the Birth of the Foetus: These Vessels are, the Umbilical Vein, which goes from the Navel by the fissure of the Liver, to the Vena Porta; the two Umbilical Arteries which pass by the sides of the Bladder, to the Iliack Ar­teries; the Ʋrachus which goes be­twixt the two Arteries to the bottom of the Bladder: these Vessels turn dry after the Child is Born, being of no use. They are all contained betwixt the doubling of the Peritoneaum. We shall speak of them more after wards.

SECT V. Of the Omentum.

THE Omentum, otherwise called [...], in English, Caul; lies under the Peritonaeum above the Inte­stines; 'tis composed of two very fine Membranes, betwixt which its Vessels, Fat, and Glands are contained. At one Extremity, it is tied to the hollow side of the Liver, to the backside of the Duodenum, to that part of the [Page 29] Colon that lies under the Stomach, Its Descrip­tion. to the Back and Spleen, from thence descen­ding below the Navel, it turns up again and ascends as high as the Sto­mach, where its other Extremity is again tied to the hollow side of the Liver, to the forepart of the Duodenum and Pylorus, to the bottom of the Sto­mach and to the Spleen; so that it resembles an Apron whose end is turned up as high as the Girdle. Sometimes it descends as low as the Os Pubis, which with the Dilatations of the Productions of the Peritonaeum causes an Epiplocele.

Its Vessels.The Gaul receives Veins from the Porta, which are the Gastro-epiplois dextra & smistra, and the Epiploioae, Arteries from the Coeliaca and Mesen­terica, and Nerves from the Intercostal. Which Vessels with some small Glands and much Fat contained in proper and distinct Cells (as hath been said above) lies betwixt the Membranes of the Caul. The Fat is gathered chiefly about the Vessels, and the Membranes of the Caul are transparent, and full of small holes where there is no Fat. Malpighius says, that he has seen the Veins and Arteries, which come from the Sto­mach and Spleen, woven like Nets, and upon them run the Ductus Adiposi, which terminate in the little Globes of [Page 30]Fat, but they were so very small, that he could not discover whether they were hollow or not; yet he thinks that they are Canals for carrying the Fat, because he has found them in Beasts very like to small Guts, equally big in all their extent. This same Author doubts whether this sort of Vessels which are spread thorow all the Fat of the Body, come from the Caul by means of the Membrana Adiposa, which may be a common source to both.

Its use.They give several uses to the Caul, as to cover the bottom of the Stomach and of the Intestines, that by cherish­ing their heat, it may promote Dige­stion, and help the Concoction of the Chyle: to strengthen and sustain the Vessels which go from the Spleen, to the Stomach, Intestines, Pancreas, and Liver, to keep a store of the Fat, that it may be received by the Veins and Lymphaticks, for the use we have spo­ken of; to supple the Superficies of the Guts for facilitating their Peristal­tick Motion.

The Caul is very subject to Corrup­tion, particularly if it be exposed to the Air, therefore in Wounds of the Lower Belly, when the Caul comes out, Surgeons take care to cut off all that is mortified of it. It grows some­times very fat and heavy; Vezalius [Page 31]says, he has seen One of fifty Pound weight, altho' ordinarily it weighs no more than half a Pound. Bartholine saw another all fleshy in the Hospital of Leyden.

SECT. VI. Of the Oesophagus.

THough the Oesophagus belongs not properly to the Lower Belly, yet because of its connexion with the Sto­mach, it will not be unproper to de­scribe it here.

Its Situation.The Oesophagus, or Gullet, is a long, large, and round Canal which descends from the Mouth, lying all along be­twixt the Aspera Arteria and the Ver­tebrae of the Neck and Back, to the fifth Vertebra of the Back, where it turns a little to the right, and gives way to the Aorta Descendens, and both run by one another till at the ninth, the Oesophagus turns again to the left, climbs above the Aorta, and descend­ing above it, it pierces the Midriff, and is continued to the left Orifice of the Stomach.

Its Coats.The Gullet is composed of three Coats; The First and Internal, which covers all the Cavity of the Gullet, is made of nervous Fibres diversly inter­woven; this Coat at its upper end doth [Page 32]join the internal Membrane of the Mouth and Lips, therefore in Vomiting these Parts are affected, and at its lower end it covers the left Orifice of the Stomach internally for three Fingers breadth: This Coat is soft and downy towards the Cavity; but more at the Orifice of the Stomach, than it is any where else.

The Second Coat of the Gullet is very thick and fleshy, it resembles a true Muscle, its Fibres run in two Spiral Lines which cross one another: by the Motions of this Coat, the Peri­staltick Motion of the Gullet is per­formed.

The Third and outermost, which covers the other two, is very thin, composed of small and slender mem­branous Fibres, it comes from the Pleura.

Among these Coats there are some small Glands, whose excretory Chan­nels open in the Cavity of the Oeso­phagus, for the moistening of it. The Gullet at its upper end receives an Artery from the Aorta, and it sends a Vein to the Azygos: At its lower end it has an Artery from the Caeliaca, and it gives a Vein to the Coronaria of the Stomach. Its Nerves are from the eighth Pair.

The Muscles of the Pha­rynx.The upper end of the Gullet is called Pharynx. It has two pair of Muscles for its Motion. The First is the Stylo­pharyngaeus. This is a small and round Muscle, which arises fleshy from the root of the Processus Styloides, and de­scending obliquely, it is inserted into the sides of the Pharynx. When this Muscle acteth it pulleth up and dilateth the Pharynx.

The Second is the Oesophagaeus. Its Fibres have several Directions; its su­perior Fibres arise from the Processus Pterigoidaeus of the Os Sphaenoides, and from the Cornua of the Os Hyoides, and run obliquely to the back-part of the Pharynx; the Fibres which are below these arise from the sides of the Carti­lago Scutiformis, and run transversly to the middle of the back part of the Pharynx, where both superiour and in­feriour Fibres from both sides unite and form a tendinous Line. When this Muscle acts, it draws the back part of the Pharynx to its forepart, by which it not only straitens it for the depressing of the Aliment, but it compresses also the Tonsillae which send out their Liquor, which lubri­cates the Aliment whereby it glides the more easily down into the Sto­mach.

There are two Glands which are tied on the backside of the Gullet a­bout the fifth Vertebra of the Back, by the branches of Nerves which come from the eighth Pair. These two Glands are like two Kidney-beans tied together; Its Glands. they receive Veins and Ar­teries from the Coronariae, and they have Lymphatick Vessels which dis­charge themselves into the Thoracick Duct. Their use is to defend (as some say) the Gullet against the hardness of the Vertebrae, and to moisten its Ca­vity for facilitating the descent of the Aliment. But it's more likely that these Glands are for separating a Lym­pha from the Blood, as others do. Bartholine remarks that these Glands sometimes swell so big as to hinder the descent of the Aliments into the Sto­mach.

Its use.The use of the Gullet is to carry the Meat from the Mouth into the Stomach, by means of the Muscles of the Pharynx, and fleshy Fibres of the Gula which perform its Peristaltick Motion.

SECT. VII. Of the Stomach.

Its Situation.THE Stomach, Ventriculus, or [...], lies immediately under the Mid­riff, [Page 35]the Liver covers a part of its right Side, the Spleen touches it on the left Side, and the Colon at its bottom, to which also the Caul is tied. Its Figure. Its figure resembles a Bag-pipe, being long, large, wide, and pretty round at the bot­tom, but shorter and less Convex on its upper part, where it has two Ori­fices, one at each end, which are some­what higher than the middle between them. The Superior or left Orifice is called [...], to it the Oesophagus is joined. Its Orifices. By this Orifice the Aliments enter the Stomach, where being di­gested they ascend obliquely to the Py­lorus or right and inferior Orifice, which is united to the first of the Intestines. At this Orifice the Tunicles of the Stomach are much thicker than they are any where else, and the inmost has a thick and strong Duplicature, which serves as a Valve to the Pylorus when it contracts and shuts.

Its Coats.The Stomach is made of four Mem­branes or Coats; The first and inmost is made of short Fibres, which stand perpendicularly upon the Fibres of the next Coat; they are to be seen plainly towards the Pylorus. This Coat is much larger than the rest, being it is full of Plaits and wrinkles, and chiefly about the Pylorus: These Plaits retard the Chyle, that it run not out of the Sto­mach [Page 36]before it be sufficiently digested. In this Coat there are also a great num­ber of small Glands which separate a Liquor, which besmears all the Cavity of the Stomach; therefore this Coat is called Tunica Glandulosa.

The Second is much finer and thiner; it is altogether nervous; it is of an ex­quisite sense, and it's called Nervosa.

The Third is Muscular, being made of straight and circular Fibres; the straight run upon the upper Part of the Stomach, between its superior and inferior Orifices, and the circular run obliquely from the upper part of the Stomach to the bottom. These Fibres by their Contraction and continual Motion help the attrition and digestion of the Aliments.

The Fourth Tunicle is common, it comes from the Peritonaeum.

The Stomach receives Veins from the Porta, Its Vessels. viz. the Gastrica, Pylorica, and Vas breve, and branches from the Gastro-epiplois dextra & sinistra, which are accompanied with branches of the Arteria Coeliaca, all which lie immedi­ately under the fourth Coat of the Stomach.

The Eight pair of Nerves or Par vagum gives two considerable branches to the Stomach, which descending by the sides of the Gullet, divide each into [Page 37]two branches, the External and Inter­nal. The two External branches unite in one, and the Internal do so like­wise, both which piercing the Midriff, form, by a great number of small twigs, upon the upper Orifice of the Stomach, a Plexus, and then the In­ternal branch spreads its self down to the bottom of the Stomach: and the External branch spreads it self upon the inside about the upper Orifice of the Stomach. This great number of Nerves, which is about the upper Ori­fice, renders it very sensible, and from them also proceeds the great Sympa­thy betwixt the Stomach, Head, and Heart; upon which account Van Hel­mont thought, that the Soul had its seat in the upper Orifice of the Sto­mach.

The Plexus Nervosus of the Hypo­chondria and Mesenterium give several branches to the bottom of the Sto­mach, therefore in Hysterick and Hy­pochondriack Passions the Stomach is also affected.

Its use.The Use of the Stomach is Dige­stion, which is the Dissolution or Se­paration of the Minute Parts of the Aliments, not only by the Saliva and Succus of the Glands in the bottom of the Stomach, but also by the con­tinual motion of its muscular Fibres; [Page 38]and when this Aliment is sufficiently dissolved in the Stomach, it is by these same Fibres thrown out at the Pylorus into the Intestines.

SECT. VIII. Of the Intestines.

What the Guts are.THE Intestines or Guts are a long Canal, which being knit all along the Circumference of the Mesenterium, by several Circumvolutions, reaches from the Pylorus to the Anus. They are six times the length of the Body in which they are: By which means the Chyle has time enough to be sepa­rate from the faces, before they are cast out at the Anus. Their Coats. They are com­posed of three Coats. The inmost is nervous, and very sensible; it is full of circular wrinkles and Plaits which re­tard the motion of the Chyle and descent of the Excrements. It is co­vered with a mucous sort of crust, which defends it against the Acrimony of the Bile. In this crust there are an infinite number of small Glands; they are placed as it were by Plotouns in the small Guts, but in the great Guts they are fewer, and are placed one by one; they lie only in that side of the Intestine which is knit to the Mesentery. Some say, that they have [Page 39]each an excretory Duct which pours [...]nto the Cavity of the Intestines a white Liquor, which serves to hasten the Separation of the Chyle from the Faeces; others think that they separate the mucosity which besmears the inside of the Intestines; and a third opinion drawn from their situation, and the Liquor which is found in them, is that they are only Caruncles placed at the Mouths of the Lacteal Veins.

The second Coat is made of Spiral and straight Fibres. The Spiral Fibres contract the Cavity of the Intestines when they act, and the straight Fibres shorten the Intestines when they con­tract.

The third and External Coat is common, it cometh from the Perito­naeum.

The Division of the Guts.Tho' the Intestines be one continued Pipe, yet Anatomists divide it into six Parts, three thin and small, and three thick and great. The three thin and small, are the Duodenum, Jejunum, and Ileum. Of the Duo­denum. The Duodenum is the first Part of the Intestines: it's about twelve fingers breadth long; it is continued to the Pylorus, from which turning down­wards, it runs under the Stomach im­mediately above the Vertebrae, towards the left side, and ends at the first of the windings under the Colon. At its [Page 40]lower end there are two Canals which open in its Cavity, one comes from the Liver and Gall bladder, called Ductus communis Cholidochus, the other from the Pancreas, called Ductus Pancreaticus. The first brings the Bile; the second the Succus Pancreaticus into this In­testine. It differs from the other two in this, that its Passage is straiter and its Coats thicker.

Of the Jeju­num.The Second is the Jejunum, it begins at the first winding of the Guts under the Colon, where the Duodenum ended; and making several turnings and wind­ings, from the right side to the left, and from the left again to the right, it is continued to the Ileum, filling all the upper part of the Umbilical Re­gion, being about 12 or 13 hands breadth long. It differs from the Ileum only in this, that it hath some more Ven [...] Lacteae, into which the Chyle passing, it is found always more empty, there­fore it's called Jejunum: And the folds or membranous circles of its inner Coat are nearer to one another, and in greater number than in the Ileum.

Of the Ileum.The Third and last of the small Guts is the Ileum, it is about 21 hands breadth long; it begins where the Je­junum ends, and making several turn­ings and windings, it fills all the lower part of the Umbilical Region, and all [Page 41]the space betwixt the Ilia, and is con­tinued transversely, not in a streight line, to the beginning of the Colon in the right side; its Passage is a little narrower than that of the Jejunum, and its Coats seem somewhat thinner.

This Intestine, because of its situa­tion, falls easily down into the Scrotum by the Productions of the Peritonaeum. In it also happens the Volvulus, when one part of this Gut enters the Cavity of another.

The thick and great Guts are the Caecum, Colon, and Rectum.

Of the Cae­cum.The Caecum, altho' small, yet is taken for the first of the great Guts; but the Ancients, who made this Division of the Guts, called the beginning of the Colon the Caecum, and what is now cal­led Caecum, they called Appendix Caeci. It is four or five fingers breadth long, and about the bigness of a Swan's Quill. It is called Caecum, because it is open only at one end, by which it is tied to the beginning of the Colon, to which it seems to be an Appendage; so that the Excrements go in and come out at the same Orifice. Its other end which is shut is not tied to the Me­sentery, but to the right Kidney, by means of the Peritonaeum. Its use is yet unknown. Some take it for a second Stomach, others for a receptacle [Page 42]of the Excrements of the Foetus in which it's always full, till after the Birth. Others say, it contains a fer­ment, and others the flatuosity of the Intestines; and others, that it separates a Liquor by some Glands which are in its Cavity; which Liquor serves to harden the Excrements as they pass thorow the Colon.

Of the Colon.The Colon is the greatest and widest of all the Intestines, and about eight or nine hands breadth long. It begins where the Ileum ends, in the Cavity of the Os Ilium on the right side, from whence ascending by the Kidney of the same side, it passes under the Concave side of the Liver, to which it is some­times tied, as likewise to the Gall Blad­der, which tinges it yellow in that place, then it passes under the bottom of the Stomach to the Spleen in the left side, to which it's also knit, from thence it turns down to the left Kid­ney, and then passing in form of an S it ends at the upper part of the Os Sacrum into the Rectum.

At the beginning of this Gut there is a Valve formed by the Production of the inmost Coat of the Intestines in this place, it hinders the Excrements which are once fallen into the Colon to return again into the Ileum. In its Cavity, there are a great number of [Page 43]Cells or membranous Circles formed by [...]ts internal Coat, they retard the Pas­ [...]age of the Excrements, that we may [...]ot be obliged continually to go to [...]tool. The fleshy Fibres of its second Coat, are greater and stronger than [...]hose of the other Intestines, because [...] greater strength was requisite to cause the Excrements to ascend. It has a strong Ligament which runs along its upper side, from the Ileum to the Rectum; it ties the membranous Cells together, and strengthens the Colon against the weight of the Excrements and force of Flatuosities: In these things it dif­fers from the other Intestines.

Of the Re­ctum.The Rectum is the last of the Inte­stines: It is a hands breadth and a half long; its Cavity is about three fingers in diameter; its Coats are thicker than those of the Colon. It begins at the upper part of the Os Sacrum, where the Colon ends, and going straight down, it is tied to the extremity of the Coccyx by the Peritonaeum behind, and to the Neck of the Bladder in Men, and in Women to the Neck of the Womb be­fore, from thence comes the Sympa­thy between these Parts. There is very much Fat about its external side, there­fore it is called the Fat Gut. Its Ex­tremity forms the Anus, into which there are three Muscles inserted. The [Page 44]first is the Sphincter Ani, Of the Museles of the Rectum. this is a fleshy Muscle, about four fingers Broad, com­posed of Circular Fibres, which em­brace the Extremity of the Rectum for three fingers height, and which hangs over the Extremity of the Rectu [...] another fingers breadth; so that in the Operation for a Fistula in Ano, there is always an Inch more of this Muscle cut than there is of the Rectum. It is connected forwards to the acceleratores Ʋrinae in Men, and to the Neck of the Womb in Women, and backwards to the Os Coccygis. Its use is to shut the Passage of the Anus, which the weight of the faeces open.

The other two Muscles are the Li­vatores Ani; they arise from the Inter­nal and Lateral side of tho Os Ischium, and are inserted into the Sphincter Ani They draw the Anus upwards. A Palsy of the Sphincter causes an involuntary running of the Excrements, and a Palsy of the Levatores causes a descent of the Anus.

Of the Vessels of the Guts.The Intestines receive Veins from the Porta, which are distributed in many small branches, called Meseraicae Another branch creeps along the Colon to the Anus called Haemorrhoidalis, it is accompanied by an Artery of the same Name. The Hypogastrick Veins and Arteries give them also some branches: [Page 45]And the Mesenterica Superior and In­ [...]erior accompany the branches of the Veins.

The Nerves which are distributed in the Intestines, come from the Inter­ [...]ostal. The Anus receives some also from the Os Sacrum; they carry the Animal Spirits necessary for the Peri­staltick Motion of the Guts.

The use of the Guts.The Aliment which was dissolved in the Stomach, being thrown into the Duodenum, is mixt with the Bile and Pancreatick Juice, which not only dis­solve and attenuate it further, but they [...]lso precipitate its grosser Parts or Fae­ces, whilst its finer Parts are, by the pressure of the Midriff, Muscles of the [...]ower Belly, and contraction of the Muscular Fibres of the Intestines, thrust into the Mouth of the lacteal Vessels. The Faeces are, by the successive motion of the Spiral Fibres, and contraction of the streight ones, thrust from one Part of the Intestines into another, [...]ill at last they are thrown out at the Anus. This Motion of these Fibres, is called the Peristaltick Motion of the Guts.

SECT. IX. Of the Mesentery, Lacteal Vessels, [...] receptacle of the Chyle, and Duct [...] Thoracicus.

The Descrip­tion of the Mesentery.THE Mesentery is a triple M [...]brane, placed in the middle of the Abdomen, almost of a circular figure with a narrow Production, to which the end of the Colon and beginning of the Rectum are tied. It is about four fingers breadth and a half in Diament its Circumference being full of Pl [...] and Foldings, is about three Ells [...] length; the Intestines, which are ti [...] about this Circumference, are about eight or nine Ells long so that to eve [...] Inch of the Circumference of the M [...] ­sentery, there are three Inches of the Intestines tied. It is strongly tied [...] the first and third Vertebre of the Lo [...] It's composed of three Membranes, the inner Membrane which is thicker th [...] the other two, and upon which the Glands and Fat lie, and the Veins and Arteries run, is its own proper Mem­brane; and the other two which co [...] each side of the proper Membrane come from the Peritonaeum.

Its Vessels.The branches of the Arteria Mesen­terica Superior and Inferior, which come from the Aorta, and the Venae Mest­raice, [Page 47]which come from the Porta, run upon its proper Membrane to the In­testines; the Nerves which come from the Intercostals, and some sprigs from those of the Vertebrae of the Loins make some Plexus, from which there goes an infinite number of small twigs to the Coats of the Intestines.

The Venae Lact [...] and Lymphatick Vessels run also throw the Mesentery. In it there are also a great number of Glands, among which there is one bigger than the rest, near its centre, called by Assellius Pa [...]creas; These Glands are surrounded with a great deal of Fat; the Lacteal Veins which come from the Intestines terminate in them, and other Lacteals arise from them, and go to the receptacle of the Chyle. Sometimes these Glands being obstructed, curn Schirrous and exces­sively big.

Its Ʋse.The Use of the Mesentery is to keep the Intestines in order, and to sustain the Meseraick Veins, Arteries, Lacteal, and Lymphatick Vessels.

Of the Ve [...]e Lacteae. Assellius was the first who found out the Venae Lacteae, in the Year 1622. They are so call'd, because they are long, transparent Vessels, which appear white by the Chyle which they contain. They are so small as that they cannot be seen, but when they are full of Chyle.

They are of two Sorts.They are of two Sorts; the first sort are called Radicales or Venae Lacte [...] primi generis; they come by little bran­ches from the Intestines, particularly from the Jejunum and Ilenum, and they run betwixt the Duplicature of the Mesenterium, where they unite and form great branches, which go to the Glands in the Mesenterium.

The second Sort are called Lactea secundi generis, they come from the Glands in the Mesenterium by several branches, which uniting, form bigge branches which carry the Chyle from the Glands to the Receptaculum.

They have Valves at certain distan­ces, as other Veins which hinder the Chyle to return into the Intestines.

The first Sort have their Orifices in the Cavity of the Intestines, covered with the slime and mucosity of the inner Tunicle of the Intestines, the Chyle which enters them is filtrated thorow the Glands which are in this Coat.

Of the Re­ceptaculum Chyli. Assellius, and almost all thought, That the Lacteae of the second Order carried the Chyle to the Liver: But Pecquet, who found out the Recepta­culum Chyli, in the Year 1651. hath shewed by Ligatures, that they go not to the Liver, but to the Recepta­culum.

This Receptacle is easily found in Bodies that are alive, but with a grea­ter difficulty in those that are dead; it is of a Vesicular Substance, which is thicker in Men than in Beasts, but its Cavity is bigger in these than in those. Bartholine, opening two Bodies imme­diately after their Death, and about four Hours after they had Eat, obser­ved three Glands, which he calls Lum­bares: The first, which was the least, was situated under the right root of the Diaphragma; and the other two, which were bigger, were situated in the Angle made by the Aorta and Emul­gents; they had Communication with one another by some Lacteal Vessels; these, (he thinks) were in stead of Pec­quet's Receptacle.

Of the Ductus Thoracicus.From this Receptacle arises a Vessel called Ductus Thoracicus which is some­times found double. This Vessel as­cends all along the Vertebrae of the Back under the Oesophagus, between the Azy­gos and the Aorta, and discharges it self of the Chyle which it receives from the Receptacle into the left Subclavian Vein, by three or four small Pipes or Branches, which have every one, at their Orifices, a small Valve, which gives a free passage to the Chyle into the Sub­clavian, but which shuts and hinders it to return back again. This Duct is [Page 50]also called Ductus Communis Lympho­ticus; because the Lymphatick Vessels discharge themselves into it. It has several Valves at certain distances, which further the ascent of the Chyle towards the Subclavian by sustaining of it, that it fall not back again into the Receptacle.

The use of the Lacteae, and Ductus Tho­racicus.The Chyle being pressed by the Pe­ristaltick Motion of the Guts into the Lacteae is received into the Receptacle, from whence it is forced by the pres­sure of the Intestines and action of the Muscles of the lower Belly into the Ductus Thoracicus, which carries it to the left Subclavian Vein to be carried with the Blood to the Heart.

SECT. X. Of the Glands in General.

THE Modern Anatomists have re­duced all the Glands of the Body to two Sorts, viz. Glandulae Conglobatae, and Glandulae Conglomeratae.

Of the Glan­dulae Conglo­batae.The Glandulae Conglobatae are formed by the several turnings of one or more particular sorts of Vessels closely tied together, and wrapt up in one common Tunicle: Such are the Testicles and Epididymides.

Of the Con­glomeratae.The Conglomeratae are such as are composed of many little Glands, each [Page 51]of which is covered with its own pro­per Coat, has its own proper Ex­cretory Vessel, which sometimes uniting with the rest, form one or more Ex­cretory Ducts, and they are all closely tied to one another by Vessels and Membranes, and all covered with one common Membrane; such are the Pan­creas, the Liver, the Salivares, &c.

The use of the Glands is to separate the Humours, such as the Bile, Urine, Spittle, and others from the Blood, which is brought to them by the Ar­teries. And tho' of this there can be no Controversy; yet what the inward Structure of the Glands is, and how they separate these Humours is very much disputed by Anatomists. There are some who will not have the Glands to differ from one another, nor yet from other Vessels, except only in this; That their Orifices or Cavities are of different Figures; that is, they are ei­ther Triangular, Quadrangular, Sept­angular, or such like. Others again think, That the Arteries and Veins are but one continued Canal, and that at the Extremity of the Artery or begin­ning of the Vein, there goes out a Vessel called the Excretory Duct, through which the Humour passes, and these Ducts have circular Orifices, which differ from one another only in mag­nitude. [Page 52]The Learned Bellinus ingeni­ously imagines, That a Gland is only a single Cylindrical Tube, which may be either Straight, Spiral, or otherwise Crooked; from which there goes one or more Excretory Ducts, as the Venae Lacteae go from the Intestines. This Tube at one end is continued to the Artery, and at the other to the Vein, both which are of a Conical Figure.

There are as many or more Opinions about the way the Humours are sepa­rated. The Ancients maintained that it was done by Ferments: but as these Ferments must mix with the Blood, to separate the Humours from it; so they must be exhausted, and there must be another Ferment to separate more, and another to separate this; and so on ad infinitum. Besides, it is impossible, That any Liquor can lie in any particular place (as the Ferments are supposed to be) through which other Liquors run con­tinually, and not be carried away with the moving Liquors. Upon these Con­siderations, the Learned Bellinus, in his Treatise, De motu Cordis & Bilis, thinks, That the Air might be this Ferment. But besides, that it may be doubted, whether there is any Air in the Blood, or not: it will be hard to conceive how the same Ferment and the same Structure of Glands can separate diffe­rent [Page 53]forts of Liquors in the several Parts of the Body. But I wish he had been more particular, and ex­plained his Opinion more fully. Those who maintain, that the Glands have Pores or Cavities of different Figures say, that none but Bodies of such Fi­gures can enter them; and therefore such and such Liquors are always sepa­rated in such and such Glands. But if they did consider, that Liquors are Susceptible of all Figures, and that membranous Tubes will yield to any Figure, and that all Bodies of a lesser Diameter than that of the Gland may pass through, they would have little reason to be of this Opinion. Those who think, that the Glands differ only in magnitude, say, That only Liquors of such and such Magnitudes can pass through such and such Glands, have no reason to brag of it: for if the Bile is made of Parts, which are bigger than those of the Urine, and the Parts of the Urine bigger than those of the Spittle, then the Spittle may pass where the Urine passes, and both may pass through the Glands of the Liver: Be­sides, there is no Liquor which has not smaller and greater Parts, so that Parts of the grossest Liquors would be found separate in the finest Glands. It were tedious to run over all the Opinions [Page 54]which are published upon this Subject. The Ingenious Dr. Cockburn, has gi­ven us one in his Oeconomia Animalis, drawn from the different Velocities of the Blood, which certainly ought to be considered in this Affair.

SECT. XI. Of the Pancreas, and Succus Pan­creaticus.

Of the Pan­creas.THE Pancreas or Sweet-bread, is a Gland of the Conglomerate sort, being composed of a number of Glands, all wrapt up in one common Mem­brane. It is situated betwixt the bot­tom of the Stomach and the Vertebrae of the Loins; it lies across the Abdomen, reaching from the Cavity of the Liver to the Spleen; it's strongly tied to the Peritonaeum. It weighs commonly four or five Ounces. It is about six fingers breadth long, two broad, and one thick. Its Substance is a little soft and supple; every little Gland has a small excretory Vessel, which uniting all together, form one common Duct about the big­ness of a Quill, clear and transparent, like to a Lymphatick Vessel; Of the Ductus Pancreaticus. this Duct runs all along the middle of the Pan­creas, and opens into the Cavity of the Duodenum, at its lower end, where there is a little Caruncle at its Orifice. [Page 55]Sometimes it joins the Ductus commu­nis Cholidochus, and then both open at one Orifice into the Duodenum. This Canal was first found by Virtsungus, and is called Ductus Pancreaticus Virt­sungi.

Of the Vessels of the Pan­creas.The Pancreas has Veins from the Splenick branch, Arteries from the Cae­liack, Nerves from the Intercostal. Its use is to separate a Liquor not acid, but of the same Nature as the Saliva, for the further Concoction and Chylification of the Aliments.

SECT. XII. Of the Liver and Gall Bladder.

Its Situation.THE Liver lies under the right Hy­pochond [...]ium. Its Convex and up­per side reaches a little beyond the Cartilago Xiphoides, and touches the Diaphragma; its Concave and under side covers the Pylorus and part of the Stomach: As also a part of the Colon, all the Duodenum, a part of the Jeju­num, and of the Omentum. When we stand, its Extremity goes near to the Navel.

Its Figure.The Liver is almost round, and pret­ty thick. Its upper side is Convex, smooth, and equal; the other side is Concave, but not so equal. In its mid­dle and forepart it is divided into two, [Page 56]by a fissure, where the Umbilical Vessels enter. The Gall-bladder is fastened to its under side, where there are three Eminences that the Ancients called Portae, of which one passes for a little Lobe. When it is full of Blood, it is of a dark red colour; when the Blood is washed out of it, 'tis pale and soft.

Its Connexion.It is fastned in the Body by three Ligaments: The first ties it to the Dia­phragma, from which it comes and pe­netrates the Substance of the Liver, into the Capsula of the Porta, where it is join'd by the Umbilical Vein. The second is the Umbilical Vein; it comes from the Navel, and enters by the great Fissure of the Liver to join the Porta: After the Birth, it degenerates into a Ligament, but is of little use for the fastening the Liver. The third is slack but strong, it comes from the Common Membrane of the Liver, and is tied to the Xiphonoid Cartilage.

Its Membrane.'Tis covered with a common Mem­brane from the Peritonaeum, besides that every Lobe and Gland has its proper Membrane.

Its Substance.The common Membrane of the Li­ver being raised, its Substance appears, which is composed of several Lobes of Glands, of a Conick figure, not easily to be distinguished in the Liver of Men. These Lobes are disposed all along the [Page 57]sides of each branch of the Vessels in the Liver; they are every one covered with a proper Membrane, and tied to one another by other Membranes, in such a manner, as that they leave also little Intervals betwixt them, which are more visible in Fish, and other im­perfect Animals. Every Lobe receives small Vessels: and tho' we cannot see where they end; yet we may presume that they go to the little Glands of which each Lobe is composed.

Its Vessels.The Vessels of the Liver are, the Vena Cava and the Porta. They are accompanied with many small branches of the Arteries, which come from the Coeliack and Mesenterica Superior, which two bring the Blood for the nourish­ment of the Liver: The Porta brings the Blood full of Bile for Secretion, and the Cava carries back the Blood that remains from both.

The Vena Porta and the Cava enter the Liver by its Concave side, and are equally distributed thorow all its Sub­stance; where ever there is a branch of the one, there is a branch of the other; so that each Lobe, and each Gland in the Love, whether on the Convex or Concave side, receive the same Vessels. The Vena Porta discharges, by the ex­tremity of its branches, the Blood as yet full of Bile, into the little Glands, [Page 58]which form the Lobes, of which the Parenchyma of the Liver is composed, where being separated from the Bile, (which is taken up by the Biliary Ves­sels, which accompany the branches of the Porta, and carried to the Gall-Bladder or Duodenum) it is carried back by the branches of the Cava.

It receives its Nerves from the Plexus Hepaticus of the Intercostal Nerve.

Besides these Vessels, the Liver has Lymphaticks, which (according to Malpighius) come from the conglobu­lated Glands under its common Mem­brane on its Concave side; they carry the Lympha from the Glands to the Re­ceptaculum Chyli.

The Excretory Vessels of the Liver.We come now to the Excretory Vessels of the Liver, which are, the Vesicula fellis and Porus Bilarius. The Vesicula fellis or Gall-Bladder, Of the Gall-Bladder. is fixed to the Concave side of the Liver. Its Figure is like that of a Pear; 'tis of a different bigness almost in every Sub­ject; the biggest is about the bigness of a little Hen-egg: When the Liver is in its natural situation, the bottom, or largest Part of the Bladder is down­wards, and the Neck or narrowest Part upwards; and then it touches the Sto­mach as well as the Colon, where it frequently dies them yellow. This Bladder is composed of three Coats, [Page 59]the outermost is common to it with the Liver; the next which is proper to it, is thick and solid, composed of transverse, oblique, and straight Fibres. The third is thin and nervous. This last Coat is covered within by a kind of crust or mucous, which preserves it against the Acrimony of the Bile. Malpighius has remarked some little Glands between its Coats, where the Cystick Arteries end, which gave him ground to think that it was the same in the Porus Bilarius. The Bladder is tied to the Liver at its Neck, by several small Vessels, which are spread in seve­ral Lobes of the Liver, accompanying some branches of the Porta and Cava. These small Vessels do commonly unite in one or two Bodies, and enter the Neck of the Bladder, they bring the Bile from the Liver into the Bladder. At the Neck of the Bladder there is a little fibrous ring, which dilates and contracts as a Sphincter for the letting out, or keeping in of the Bile.

Of the Ductus Cysticus.The Ductus Cysticus is a Conduit from the Neck of the Bladder to that Part where the Porus Bilarius joins it; 'tis of the bigness of a Goose quill. These two together make the Ductus communis Cholidochus, which goes ob­liquely to the lower end of the Duo­denum, or beginning of the Jejunum. [Page 60]After it has pierced the first Coat, it runs near two fingers breadth between the Coats, before it opens in the Ca­vity of the Intestine; which oblique insertion serves instead of a Valve to hinder the Bile to return into the Du­ctus Communis, having once entered the Intestine.

The Gall-Bladder has two Veins from the Porta, which are called Cy­sticae Gemellae. It has some small Arte­ries from the Caeliaca Dextra, and some Lymphaticks.

Of the Porus Bilarius.The Porus Bilarius is another Excre­tory Vessel of the Liver. It has as many branches as the Vena Porta, which it accompanies thorow every Lobe and Gland in the Liver, wherever there is a branch of the one, there is a branch of the other; and these two are enclosed in one common Capsule as in a sheath the use of this Capsule is to facilitate the Motion of the Blood and Bile, which otherwise would be too slow, if they were not hastened by the Con­traction of this Capsule. All these branches unite, and make one trunk of the bigness of a small Quill, which joins (as we have said) at the end of the Ductus Cysticus, for the carrying the Bile from the Liver to the Intestines. by the Ductus communis Cholidochus.

The insertion of the Porus Bilarius into the Ductus Cysticus, is oblique with its Mouth looking towards the Ductus Communis, by which means it is im­possible that the Bile which comes from the Cystus can enter the Porus.

The Porus Bilarius is found in the Liver of all Animals. It is not so with the Vesicula fellis. The Hart, Camels, Goats, Dolphins, Sea-Calves, Pigeons, and many others have it not.

The Bile which is found in the Gall-Bladder, is thinner, and different from that which is in the Porus Bilarius. This Malpighius proves by an Expe­riment, which is, that having tied the Ductus Cysticus, he remarked that the Bile which came by the Porus Bilarius, was of a different taste, smell, colour, and consistency, from that in the Gall-Bladder.

The use of the Liver and Bile.The Blood which is brought by the Vena Porta into the Liver, being sepa­rated from its Bile by the Glands which compose the Substance of the Liver, is carried back by the Vena Cava, whilest the Bile is partly taken up by the biliary Vessels, which open in the Neck of the Gall-Bladder, and partly by the branches of the Porus Bilarius; from both which it runs by the Ductus com­munis Cholidochus into the Duodenum, to attenuate and perfect the Chyle, and [Page 62]to precipitate its grosser Particles by Fermentation.

The Analysis of Bile.In the Bile, there is more fix'd than volatile Salt, a little Sulphur, and a little Earth, much Phlegm. Volatile Spirits, Alcali's, and Acids, mixt with it, cause no Alteration, nor Fermen­tation, the Acids only precipitate a little Earth in it.

SECT. XIII. Of the Spleen.

Of the Situa­tion, Connexi­on and Shape of the Spleen.THE Spleen is situated in the lest Hypochondrium, under the Dia­phragma, between the Ribs and the Stomach, above the left Kidney: It is tied to the Peritonaeum, to the Stomach, and to the Omentum. It is of a blewish or leaden colour, of an oblong figure, thick at the edges, not thin as the Liver. It has two Membranes. The External comes from the Peritonaum. The Internal is proper to it.

Of its Exter­nal Mem­brane.The External is pretty strong, it has Nerves from the Intercostal, and Veins from the Splenick branch of the Porta, as it enters the Spleen, which form a sort of Plexus upon this Mem­brane.

Some of its Arteries come from the branches that are in the Internal Sub­stance of the Spleen. It has a great [Page 63]number of Lymphatick Vessels, which draw nearer to one another as they ap­proach that part where the Veins and Arteries enter the Substance of the Spleen, to discharge themselves of a yellowish coloured Lympha, into the Receptaculum Chyli. There are more of them upon a Calf's Spleen than upon a Man's.

Of the Inter­nal Mem­brane.The Internal Membrane is finer and thinner than the External: for if you blow into the Splenick Artery, the Air shall pass thorow the one, but not the other; its Fibres are not irregularly woven, as those of other Membranes seem to be, but they come from innu­merable Points, as Rays from so many Centres; and the Fibres of one Point are regularly woven, with the Fibres of the Points surrounding it. It receives Veins, Nerves, and Arteries from those that enter the Spleen.

The Substance of the Spleen is not only kept together by its common Membranes, but also by innumerable Fibres which come from the Points of the internal Membrane, and are inser­ted in the Points of the opposite side of the same Membrane, the Expan­sion of the Extremity of these Fibres seem to compose the Internal Mem­brane.

Of the Sub­stance of the Spleen.The Substance of the Spleen is com­posed of an Infinity of Membranes, which form little Cells and Cavities of different figures and bigness, which communicate with one another, and which are full of little Glands.

The Membranes which form these Cells, come from the Internal Mem­brane of the Spleen, but Malpighius thinks rather from the Sinus Venosus, by which they all communicate, not only at the Extremities of the Capil­lary branches, but also at some small holes, which are in the Trunk and great branches of this Vein, which open immediately into the Cells; these Membranes are nourished by the Ca­pillary Arteries, which frequently make small Plexus upon them.

Of its Glands.These membranous Cells are full of small Glands, of an Oval figure, a soft substance, and a white colour. They seem to be hollow in the middle. There are seven or eight of them toge­ther which hang at the Extremities of the Nerves and Arteries as so many lit­tle Grapes.

Of its Veins.The Spleen has Nerves, Veins, and Arteries, which no sooner enter its Sub­stance than they are received in one common Capsula, which contains not only their great Trunks, but all their branches. This Capsula is thick in that [Page 65]side that the Nerves and Arteries lie on; but thin, and liker a Net than a Membrane, on the side that the Vein lies on.

The Splenick Vein comes from the Porta: before it enters the Spleen it has two Coats, the inner fine and thin, the outer strong and thick, which goes no further than the internal Membrane of the Spleen, with which it unites. This Vein is divided into three or four branches, each of which send out others at a certain distance by two and two, and all these end in the Cells of the Spleen. In its great branches on the opposite side, to that whereon the Ar­teries and Nerves lie, there are many little holes which open immediately into the Cells (as we have said before) it is not the same in the Arteries.

The Splenick Artery comes from the Coeliaca. Arteries. As soon as it enters the Spleen, it is divided into as many bran­ches as the Vein which it accompanies thorow all its Substance, and its Capil­lary branches terminate in the Cells and Glands.

The Nerves are two from the Plexus Splenicus; Nerves. they accompany the Arte­ries with which they are included in a particular Capsule which comes from the common Capsule; they inosculate several times, and form a sort of Net upon their particular Capsule.

The use of the Spleen.The true use of the Spleen is yet un­known. The Ancients thought that it was the receptacle of the Melancholick humour, some considering that in the Spleen there are a great number of Membranes and Fibres, and also many Nerves, think that the Blood is atte­nuated, and becomes more spirituous in the Spleen; and considering that the most of the Blood in the Liver comes immediately from the Spleen and O­mentum, they think that the one fur­nishes the Oleaginous, the other the Spirituous part of the Bile. This Opi­nion seems pretty probable, but then to what end are the Glands in the Spleen? others therefore to give an use to the Glands think that they separat [...] a Liquor from the Nerves and Arterial Blood, which is carried by the Porta to the Liver. But then to what end is a Liquor separated from the Blood to be immediately mixt with it again? Nature has given to the Glands every where else their proper Excretory Ves­sels, by which we know their several uses; and till we discover those of the Spleen, it's probable we shall be igno­rant of its true use.

SECT. XIV. Of the Kidneys, Glandulae Renales, Ʋreters and Bladder.

Of the num­ber and figura of the Kidney.THE Kidneys are two in Number, one on each side; they have the same figure as the Kidney-beans; their length is four or five fingers breadth; their breadth is three, and their thick­ness two; the right is under the Liver, and the left under the Spleen. In a foetus their External Substance is divi­ded into several Lobes join'd together, which in Adults become more close; therefore their Superficies is equal and smooth; they have two Membranes, the one common from the Peritonaeum, the other proper; they are ordinarily covered with much Fat; their colour is a dark red.

Of their. Vessels.We observe in the Kidneys, Lym­phatick Vessels which discharge them­selves into Pecquet's Reservatory, Nerves which come from the Intercostals, Veins from the Cava, Arteries from the Aorta.

These Veins and Arteries are called Emulgents; they enter the Reins by their Concave sides, (which lies nearest the Cava and Aorta) included in one Cap­sule, and are divided into several bran­ches, which surround the Pelvis. These [Page 68]branches are again divided into an infinity of others less, which go to the external Part of the Reins, where they join by several Anastomoses; and form a sort of Net, from which their Ex­tremities coming, terminate in an infi­nity of little Glands.

Their Sub­stance.These Glands are of a round figure, they compose the outer Substance of the Reins, which is half a finger thick. From each of them there goes a long and small Tube, these Tubes compose the inner Substance of the Reins. As they approach the Pelvis or Bason, they gather together in little bundles, whose Extremities piercing the Membrane of the Pelvis, form those little Protube­rances on the inside of the Pelvis, called Papillae. Of the Pelvis. The Pelvis or Bason is a Ca­vity in the middle of the Kidneys co­vered with a Membrane, which is a dilation of the Ureters; and from the External side of this Membrane go se­veral membranous Appendices towards the External Substance of the Kidneys. In their way they form a sort of Net-work, which divide the Urinary Tubes into bundles, and which make a sort of Capsula to the Blood Vessels.

The use of the Kidneys.The use of the Reins is to separate the Urine from the Blood, which by the motion of the Heart and Ar­teries is thrust into the Emulgent [Page 69]branches, which carry it to the little Glands, in which the Serosity, being separated, is received by the Orifice of the little Tubes, which go from the Glands to the Pelvis, from whence it runs by the Ureters into the Bladder. The Blood which was carried into the Glands, and which could not enter their excretory Tubes, is brought back by the emulgent Veins.

Of the Glan­dulae Renales.In the middle between the Aorta and the Kidneys, a little above the emul­gent Vessels, are situated the Glandulae Renales or Capsulae Atrabilares. They are two in number, one on each side wrapt up in some Fat; they sometimes change their situation, and their figure is also various; for in some they are round, in others oval, square, triangu­lar, of a trapeze or irregular figure; the right is ordinarily bigger than the left; and each about the bigness of a Nux Vomica: In a foetus they are al­ways almost as big as the Kidneys. They are covered with a fine Mem­brane, and they have a pretty large Cavity, in which there is found a blackish sort of Liquor. Their co­lour without is like a red drawn upon brown, but within it is a more lively red. There are some little holes in their Substance, which open into their Cavity.

Their Vessels and use.The Emulgent Vessels, and some­times the Cava and Aorta, send them one or two branches of Veins and Ar­teries. The intercostal Nerve furnishes a branch, which makes a Plexus upon them. Their use is not yet known. They seem to separate a Liquor from the Arterial Blood before it goes to the Reins, for the liquefying the Blood which is too thick after it comes from them.

Of the Ʋre­ters.The Ureters are two long and small Canals which come from the Basons of the Kidneys, one on each side; they lie betwixt the doubling of the Perit [...] ­naeum, and descending in the form of an S; they pierce the Bladder near its Neck, where they run first some space betwixt its Coats, and then they open in its Cavity.

They have two Coats, one common from the Peritonaeum, the other proper which is very sensible; they have Veins and Arteries, and Nerves from the In­tercostals, and from those which come from the Vertebrae of the Loins. Such as are subject to the Gravel, and given to excessive Drinking, have them some­times so much dilated, that you may put the end of your little Finger into them. Their use is to carry the Urine from the Reins to the Bladder. Their Obstruction causes a suppression of the Urine.

Of the Blad­der.The Bladder is a Vessel of the figure of a Pear, situated between the Dupli­cature of the Peritonaeum, in the lower Part of the Abdomen, between the Os Sacrum and the Os Pubis, above the straight Gut in Men, and the Neck of the Womb in Women: It's tied to the Navel by the Ʋrachus degenerated into a Ligament, and its sides to the Um­bilical Arteries; its Neek to the Intesti­num rectum in Men, and to the Neck of the Matrix in Women. Its Sub­stance is composed of three Coats. The first is from the Peritonaeum. The se­cond is composed of straight, circular, and transverse Fibres for its Contra­ction; And the third is Nervous and full of wrinkles, for facilitating its Contraction and Dilatation. This last is covered with a viscous and slimy Matter, which defends it from the acri­mony of the Salts in the Urine. Its Neck is longer in Men than in Women, where it has a little Muscle, called Sphincter, whose Fibres are circular, its use is for shutting the Orifice of the Bladder. The Body and Neck have Veins and Arteries from the Hy­pogastrick, Nerves from the Inter­costals, its use is to be a Reservatory of the Urine.

Such Animals as have no Bladder, have no Spleen, as Lizards, Camels, and [Page 72]others. We find in the Urine much Phlegm and volatile Salt, a little Sul­phur, Earth, and fixt Salt.

SECT. XV. Of the Parts of Generation proper to Man.

THE Vessels and Parts of Generation proper to Men are, The Vasa Praepa­rantia, the Testes, the Epididymedes or Parastatae, the Vasa Ejaculatoria, the Vesiculae Seminales, the Prostatae, and the Yard.

Of the Vasa Praeparantia.The Vasa Praeparantia are four in number, two on each side; which are, one Vein and one Artery. The Vein on the right side comes immediately from the Cava, a little below the Emulgent; that on the left side comes from the Emulgent, because if it came from the Cava, it must needs cross the Aorta, which by its frequent beating would quickly break it, or at least stop the motion of the Blood in it. The Vein on the right side, as soon as it comes from its Trunk, gives some branches to the Peritonaeum and Omen­tum. The Arteries come both in me­diately from the Aorta, about two fingers breadth below the Emulgent Arteries.

As soon as the Veins and Arteries are come from their Trunks, they [Page 73]pierce the inner Membrane of the Peri­tonaeum; and being both wrapt up in the same Coat, they descend above the Muscle Psoas, betwixt the two Mem­branes of the Peritonaeum. The Vein di­vides and unites several times, and so by diverse Divisions, it passes with the Ar­tery thorow the rings of the transverse and oblique Muscles, within the Pro­ductions of the External Membrane of the Peritonaeum to the Testicles, and four fingers breadth above them, it be­gins to form the Corput Varicosum or Pyramidale, which is a Pyramidale Fi­gure made by the Divisions of this Vein, whose basis is upon the Testicles, these Veins are full of Valves.

The Artery divides only in two bran­ches, three or four fingers breadth above the Testicle, upon which the greater branch is bestowed, by which many small branches are spread thorow all its Substance, the lesser goes to the Epididymides. There descends also with these Vessels into the Testicles, two branches of the Intercostal Nerves, and of the twenty one of the Spine, which carry Animal Spirits to the Testicles; besides these Veins, Arteries, and Nerves, the Testicles have also Lymphaticks, which discharge themselves into the common Receptacle.

Of the Scro­tum.The Testicles are contained in the Scrotum, which is composed of [...] Membranes, besides the Scarsskin; Th [...] First is the Skin, which in thin, and without Fat in this place, but full of Veins and Arteries. The Second is called D [...]rt [...]; it's a thin Memb [...] made up of fleshy or muscular Flora, by means of which the Scrotum is wrinkled and contracted. There are some Men who can contract and [...] ­la [...]e it, when, and as they please. The Scrotum is divided in the middle by a thin Membrane, which separates the two Testicles. When the Scrotum is little and contracted, it is a sign of health; its use is to contain both the Testicles.

The Testicles are not always found in the Scrotum; they are sometime (tho [...] rarely) in the Abdomen: Of the figure and bigness of the Testicles. They are of an oval figure, the bigness of a little He [...]s Egg; they are two in number; I know those who have three.

The Testicles have two Coats; [...] Authors say, three.

Of the Tuni­ca Vaginalis.The First is called Elythroides or Va­ginalis, formed by the Dilatation of the Productions of the external Mem­brane of the Peritonaeum; its inte [...] Superficies is smooth, its external rough [...] it contains the Vasa Praeparantia and [Page 75] Deferentia; it embraces loosely the whole Body of the Testicle. This Tu­nicle is almost all covered by a Muscle called Cremaster, which rises from the Os Pubis, and spreading its Fibres up­on the Elythroides, it suspends the Te­sticles, and draws them up in the act of Generation.

Of the Albu­ginea.The Second is that which covers im­mediately the Testicles. It is called Albuginea, because of its white colour. It is strong and thick, very smooth and equal, the Coats of the Vasa Praepa­rantia are united to it.

Of the Sub­stance of the Testicles.The Substance of the Testicles which formerly was thought to be a sort of Marrow, is nothing but the folding of several small Vessels, which have no conspicuous Cavity, disposed in such a manner, that if they could be separate from one another, without breaking them, they might be drawn out to a great length. These Foldings are sepa­rate from one another by thin Mem­branes, which come from the inner side of the Albuginea. At the end of the Testicles, Of the Epi­didymi [...]. they send out six or seven small Vessels, which piercing the Tu­nica Albuginea, unite into one Canal, which by several turnings and wind­ings upon the upper part of the Testi­cles, forms this Body which we call Epididymis. They are covered with a [Page 76]thin Production of the Albuginea The same Canal continuing and ascen­ding from the Extremity of the Epi­didymedes, Of the Vasa Deferentia. forms the Vasa Deferentia or Jaculatoria, one from each Epididy­mis, about the bigness of a Goose-quill, with a conspicuous Cavity; as they ascend within the Tunica Vaginalis, they make several Serpentine turnings and windings; then, they enter by the holes of the transverse and oblique Muscles into the Abdomen, and march­ing over the Ureters, between the back­side of the Bladder and the Rectum, they grow larger as they approach the Vesiculae seminales, (which discharge their humour into them) where they come close to one another, and grow­ing again smaller and smaller, they pass thorow the Prostatae, and open into the Ʋrethra, a little below the Neck of the Bladder, where each Ori­fice has a spongious border, which hin­ders the involuntary running of the Seed; they may sometimes be mista­ken by Surgeons for a Carnosity of the Yard.

The Spermatick Arteries carry the Blood from the Aorta to the Testicles, which separate that Part of it which is fit for Seed. The Veins carry back to the Cava what Blood remains, after the Secretion of the Seed, and the Nou­rishment [Page 77]of the Parts. The Seed is further purified in the Epididymides and in coition is carried by the Vasa Deferentia into the Ʋrethra.

Of the Vesi­cu [...]e Semi­nales.The Vesiculae Seminales are two in Number, one on each side, situated betwixt the Bladder and the straight Gut, tied to the one and the other by a Membrane of fleshy Fibres, which in time of Coition, swells and presses the Vesiculae. They are covered with a a pretty thin Membrane, upon which do creep many branches of Veins, Ar­teries, Nerves, and Lymphaticks. Their External Surface resembles that of the Intestines of a little Bird, which in some places of their Circumvolitions are broad, in others narrow; they are about three fingers breadth long, their broadest part is about an inch, from which they grow narrower by little and little to their end which is next the Prostatae. They have two conside­rable Cavities divided into membranous Cells, which open distinctly by two Orifices which are in their small Ex­tremities, into the two Vasa Deferentia, into which they discharge a pretty thick and clear humour which embra­ces the true Seed which comes from the Testicles.

Of the Pro­statae.The Prostatae or Corpus Glandulosum, is situated at the Neck of the Bladder, [Page 78]covered with a Membrane made of muscular Fibres, as that of the Vesiculae, and for the same use. It is about the bigness of a Walnut; the Vasa Defe­rentia pass thorow its Substance, which is Vesicular and Glandulous, full of an oleaginous and viscous humour, which is carried into the beginning of the Ʋrethra, by eight or nine excretory Ducts, which open about the Orifices of the Vasa Deferentia; the border of their Orifices is also spongious, to hinder a continual running of this humour.

The Prostatae have Veins, Arteries, Nerves, and Lymphaticks. They are the Seat of the Gonorrhaea's; for it the morbifick Matter fixes in them, it en­flames, corrodes, and ulcerates them▪ from whence there is a continual run­ning of purulent Matter.

Of the Yard.The shape, figure, and dimensions of the Yard are well enough known. It is covered with the Skin and Scarf­skin. The Skin at the end of the Yard folds in, and forms a Hood to the Glans, called Praeputium, which is fixed to the lower part of the Glans by a little Ligament called Fraenum. The Substance of the Yard is composed of two nervous Bodies, called Corpora Ca­vernosa, they arise at two different pla­ces, from the lower part of the Os [Page 79]Pubis; a little from their root they come close together, being only divi­ded by a Membrane, which at its be­ginning is pretty thick, but as it ap­proaches the end of the Yard, it grows thinner and thinner, and the two ner­vous Bodies terminate in the Balanus. The External Substance of these ner­vous Bodies is hard, firm, close, and nervous; the Internal is membranous, loose, and spongious, full of Veins and Arteries.

Of the Bala­nus.The Balanus or Glans is only a con­tinuation of the soft and spongious Internal Substance of the two nervous Bodies, covered immediately with a thin Membrane, which is a Dilatation of the Internal Membrane of the Ʋre­thra. About the Crown of the Glans, where the Praeputium is contiguous to it, there are several small Glands which lie under its thin Membrane; they separate a whitish humour for the moistening the Balanus. In a Phimosis this humour not only hardens, but may grow acid, and ulcerate the Glans.

Of the Ure­thra.The Ʋrethra is a Conduit which reaches from the neck of the Bladder to the end of the Yard, in the middle and lower part of the two nervous Bodies. Its Substance is externally hard, and internally spongious, like that of [Page 80]the nervous Bodies, except a little at the neck of the Bladder, which is mem­branous. With in its Cavity is covered with a thin and exquisite Membrane, in which some have observed several Glands, which separate a Liquor for preserving it against the Acrimony of the Urine.

Of the Vessels of the Yard.The Yard has a small Ligament which arises from its back a little distance from its root, which ties it to the up­per part of the Os Pubis, that it may not hang too low. It receives two branches of Veins and Arteries from the Hypogastrick Vessels; besides others from the Pudenda they are distributed thorow all the body of the Yard, par­ticularly thorow the spongious Part of the Corpora Cavernosa and Ʋrethra. The two Veins unite near its roots, and form one trunk which runs along the upper side of the Yard. It has two Nerves from the Os Sacrum, and seve­ral Lymphaticks, which empty them­selves into the Inguinal Glands.

Of its Muscles and Erection.The Yard has two pair of Muscles. The First is the Erectores; they rise from the Ischium, a little below the roots of the two nervous Bodies, they lie upon them, and are inserted into them. The Second are the Accelera­tores, they rise from the root of the Ʋrethra; they have several Fibres [Page 81]which join the Fibres of the Sphincter Ani, they lie upon the Ʋrethra, betwixt the two former, and are inserted into the nervous Bodies. When these Mu­scles act, they compress the Veins of the Penis against the Os Publis, and so stop the Blood from returning, whilst the Arteries still bringing more, must necessarily swell and distend the spon­gious Part of the nervous Bodies, and Ʋrethra, which is the true cause of an Erection; for if you stop the Veins of the Yard in any Cadaver, and inject a Liquor by the Arteries, the Yard shall swell as in a Natural Erection.

SECT. XVI. Of the Parts of Generation proper to Women.

HAving given an exact Account in the First Chapter, of the Figure and Situation of the External Parts of Generation proper to Women; I shall here only examine their Substance and Use, and then proceed to the other Parts.

Of the Cli­toris.The Clitoris, which is in the upper part of the Vulva, is a long and round Body naturally about the bigness of the Ʋvula; it begins to appear well about 14 Years of Age; it is covered with a folding of the Skin of the Vulva; called [Page 82]its Praeputiam. The Substance of the Clitoris is composed of two nervous Bodies, such as those of the Yard; they rise at two different places in the lower Part of the Os Pubis, and approaching one another, they unite and form the Body of the Clitoris, whose Extremity, which is of an exquisite sense, is called its Glans. The two nervous Bodies before they unite, are called the Crura Clitoridis; they are twice as long as the Body of the Clitoris. Its Muscles. It has two Muscles, which rise from the Protu­berance of the Ischium, and are inserted in its nervous Bodies. They erect the Clitoris in the Coition, after the same manner that the Muscles of the Yard do erect the Yard.

Its Vessels.The Clitoris receives Veins and Arte­ries from the Haemorrhoidal Vessels and the Pudenda, Nerves from the In­tercostals, which are afterwards distri­buted thorow all the Parts of the Vulva. Remark that the Veins on the one side of the Vulva communicate with those of the other side, and so do the Arte­ries communicate with one another.

Of the Nym­phae.The Nymphae have been sufficiently described already. Their internal Sub­stance is spongious and full of Blood Vessels, therefore they swell in the act of Copulation; they receive Vessels and Nerves as the Clitoris: Their Use is to [Page 83]defend the internal Parts from external Injuries, to encrease the Pleasure in Coition, to direct the course of the Urine: they are bigger in married Wo­men than in Maids.

The Hymen is a membranous Circle or Ring, at the Mouth of the Vagina; Hymen. which being broke at the first Copu­lation, its Fibres contract in three or four places, and form what they call Glandulae Myrtiformes.

A little beyond the Clitoris, in the upper part of the Vulva, above the Neck of the Womb, there is a little hole, Urethra. which is the Orifice of the Ʋre­thra. It is naturally so large as to receive a Probe as big as a Goose-quill; it is covered within by a sine Membrane. The length of the Neck of the Blad­der is almost about two singers breadth. It has a little Musele called its Sphin­cter, which embraces the Ʋrethra, to hinder the involuntary running of the Urine; it joins the fleshy Fibres which are at the Orifice of the Vaginae.

Between this Muscle and the inner Membrane, Lacunae. there is a white and glandu­lous Substance, almost a finger breadth of thickness; it surrounds all the Neck of the Bladder; in it there are many little Excretory Vessels called Lacunae, which discharge themselves of a viscous Liquor, for the tickling of the Sex, [Page 84]into the lower part of the Vulva. This glandulous Body is the Seat of Go­norrhoea's in Women, as the Prostate are in Men; it has the same use that they have. It hath been found all ul­cerate in Women which have had a Gonorrhaea.

The Vagina, Vagina. or Neck of the Womb, is a long and round Canal, which tea­ches from the Pudenda to the internal Mouth of the Womb. In Maids 'tis about five fingers breadth long, and one and a half wide; but in Women who have born Children, its length and bigness cannot be determined, be­cause it lengthens in the time a Woman is with Child, and it dilates in the time of Birth. It lies betwixt the Bladdes and the Rectum, with which last it is wrapt up in the same common Mem­brane from the Peritonaeum; for this reason the Excrements come out some times by the Vulva, when this Intest [...] is wounded.

The Substance of the Vagina is com­posed of two Membranes, of which the inner which lines its Cavity, is nervous and full of wrinkles, like the roof of the Mouth of an Ox, especially in is forepart. There are may little Vessels which pour into it a viscous humon [...] in the time of Coition, of which we have spoken before.

The wrinkles of this Membrane, are for the Friction of the Balanus, to en­crease the Pleasure in Copulation, to detain the Seed that it run not out again, and that it may extend in the time of Gestation.

The External Membrane of the Va­gina is made of muscular Fibres, which (as occasion requires) dilate and con­tract, become long and short for ad­justing its Cavity to the length and bigness of the Yard. At its lower part there is a Muscle of circular Fibres, like a Sphincter, and under it on each side of the Vagina, a Body composed of Vessels and Fibres which they call Plexus Retiformis; both of them help to straiten the Mouth of the Vagina, that it may grasp the Yard closely.

The Neck of the Womb receives Veins and Arteries from the Hypoga­strick and the Haemorrhoidal Vessels. Those from the Hypogastrick are dis­persed in its upper part, and those from the Haemorrhoidal in its lower part These Vessels communicate with one another. Some of them open into the Cavity of the Vagina, and pour out part of the Blood which makes the Menstrua. It has Nerves from the Os Sacrum. Amongst other uses, the Neck of the Matrix serves for a Conduit to the Menstrua, and for a Passage to the Foetus.

Of the situa­tion of the Matrix.The Matrix or Womb is simated in the lower part of the Hypogaster, be­twixt the Bladder and the straight Cut; the Os Pubis is a fence to it be­fore, the Sacnum behind, and the [...] on each side; they form as it were a bason for it; but because it must swell whilst a Woman is with Child, there fore they leave a greater space in them than in Men; it is for this reason that Women are bigger in the hauncher than Men.

Of its Figure.The figure of the Womb is like a Pear, from its internal Orifice to its bottom, 'tis three fingers long, two broad, and almost as much thick. In Maids its Cavity will contain a big Al­mond: It changes both figure and di­mensions in Women that are with Child; it presses the Bowels, and tea­ches to the Navel towards their Deli­very, whilst at other times it does not pass the Os Sacrum.

Of its Sub­stance.The Womb is covered with an ex­ternal Membrane, which it receives from the Peritonaum. Its Substance is composed of fleshy Fibres, which are woven together like a Net, and they draw together and make several bundles which have several directions for the better contracting of the Womb in the expulsion of the Foetus. The Space between these Fibres, are filled up with [Page 87]thin and soft Membranes, which form an infinite number of Cells, upon which the Blood Vessels run; turning and winding in great abundance. Upon these Membranes, especially towards the Cavity of the Womb, there are several Glands which separate an humour to lubricate the Cavity of the Womb in the time of Pregnation.

The bottom of the Womb grows thick, as it dilates; so that in the last Months of Gestation, 'tis at least an inch thick, especially where the Pla­centa adheres, because of the abundance of Blood that is brought to it by the Arteries.

The entry into the Cavity, or the Mouth of the Womb, which joins the upper end of the Vagina, makes a little Protuberance in form of Lips, which resembles the Muzzle of a little Dog, it opens to receive the Seed in its Cavity, and shuts very exactly after Concep­tion.

Of it Vessels.The Womb receives Veins and Ar­teries from the Hypogastrick and Sper­matick Vessels, they divide and creep along it by many turnings and wind­ings, to the end they may not break when it dilates; the Veins on one side communicate by Anastomosts with the Veins on the other side: In like man­ner do the Arteries; many of them [Page 88]open in the inside of the Womb, and once every Month they pour out a little Blood, which runs thorow the Vagina out at the Pudenda; this Blood is called the Menstrua, or Courses; they begin about 14, and continue till about the 60. year of Age.

Its Nerves come from the Intercostals, and from those which come from the Os Sacrum. There are also several Lym­phaticks upon its outside, which unite by little and little into great branches, and discharge themselves in the Reser­vatory of the Chyle.

Of its Liga­ments.The Womb is tied by two sorts of Ligaments, by two broad, called Liga­menta Lata, and by two round, called Ligamenta Rotunda. The two broad Ligaments seem to be a Production or Continuation of the Peritonaeum, they come from the Ilia, and are inserted in the sides of the bottom of the Womb; for their largeness and figure, they are commonly compared to the Wings of a Bat. Their Substance is membranous as the Peritonaeum, but mixed with some fleshy Fibres: besides the Womb they sustain the Spermatick Vessels, the Ova­ria or Testicles, and the Tubae Fallo­pianae.

The two round Ligaments, rise from the fore and lateral Part of the bot­tom of the Womb, and pass in the [Page 89]Productions of the Peritonaeum thorow the rings of the oblique and transverse Muscles of the Abdomen to the Os Pu­bis, where they expand like a Goose-foot, and are partly inserted in the Os Pubis, and are partly continued or joined to the Musculus Membranosus or Fascia Lata, on the upper part of the inside of the Thigh, from thence comes the Pain that Women big with Child feel in this place. The Substance of these Ligaments is hard, but covered with a great number of Blood Vessels: they are pretty big at the bottom of the Womb, but they grow smaller and smaller as they approach the Os Pubis.

Of the Sper­matick Vesselt.The Spermatick Vessels in Women are four, as in Men; they differ only in this, that they are shorter, that the Artery makes several turnings and windings as it goes down, that it di­vides into two branches, of which the smallest goes to the Ovarium, the biggest divides into three more, of which one is bestowed upon the Womb, another upon the Vagina, and the third upon the Ligaments of the Womb and Tubae Fallopianae; 'tis the same as to the Vein.

Of the Situa­tion and Figure of the Ovaria.The Ovaria are tied about two fin­gers distance from the bottom of the Womb, by a Ligament which some Anatomists have taken for the Vasa [Page 90]Deferentia. They are fixed to the Pe­ritonaeum at the Ilia by the Sper [...]tick Vessels, and by the Membranes which cover them. They are of an Oval figure, a little flat upon their upper Part, where the Spermatick Vessel [...] enter.

The Ovaria or Testicles are about half as big as Mens are; their Surface is unequal and wrinkled in old Women, but smooth and equal in Maids; they are covered with a proper Membrane, Of their Membranes and Substance. which sticks close to their Substance, and with another common from the Peritonaeum, which covers also the Sper­matick Vessels. Their Substance is com­posed of Fibres and Membranes, which leave little spaces in which there are several small Vesicles, round, full of water, which being boiled, hardene [...] the white of an Egg; they have eath of them two proper Membranes, upon which there are several small tw [...] go [...] Veins, Arteries, and Nerves. Th [...]se Vesicles are called Eggs, and they are of a different size, and number, in Wo­men of different Age. Such of the [...] as are impregnant after Copulation, are contained or covered all over with [...] ­glandulous Body, which has a small hole in its side, thorow which they are thrust when they fall into the T [...] Fallopianae. Besides the Spermatick Ves­sels, [Page 91]the Ovaria have Nerves from the Intercostals and Lymphaticks, which discharge themselves into the common Receptacle.

Of the Tubae Fallopianae.The Tubae Fallopianae are situated on the right and left side of the Womb; they rise from its bottom by a narrow beginning, and they dilate in form of a Trumpet to their Extremities, where they are contracted again into a small Orifice, from whose Circumference they dilate into a pretty broad Membrane, which looks as if it were torn at its edges, therefore called Morsus Diaboli. Their Cavity where they open into the Womb, will scarcely admit of a Hog's bristle; but at its widest part, it will take in the end of one's little finger. These Tubes are tied below the Testi­cles by a thin large Membrane. Their Substance is composed of two Mem­branes, the one external, the other in­ternal, a little wrinkled which covers all their Cavity. These Membranes come from the external and internal Membranes of the Womb. The Tubes are about four or five fingers breadth long, they have the same Veins, Ar­teries, Nerves, and Lymphaticks as the Ovaria. These are all the Parts of Ge­neration in Women.

The Ʋse of these Parts in Generation.So great is the Pleasure in the act of Generation, that it alters the course of [Page 92]the Blood and Animal Spirits, which then move all the above described Parts, which before lie quiet and at rest. The Clitoris is erected, which by its exqui­site sense, affords a great deal of De­light, the Glands about the Neck of the Womb, being pressed by the swel­ling of the neighbouring Parts, pour forth a Liquor to facilitate the Passage of the Yard, and to encrease the Plea­sure. The Neck of the Womb con­tracts and embraces closely the Yard; the Fibres of the Womb contract and opens its Mouth (which at other times is extreamly close) for the reception of the spirituous Part of the Seed, and by the extraordinary motion of the Blood and Animal Spirits, the membranous Expansions of the Extremities of the Tubae Fallopianae, being erected and ex­tended, embrace the Ovaria for the carrying the Seed to them. The Seed impregnates the Egg, which from be­ing transparent, becomes Opake some time after; 'tis covered with a thick and glandulous Body which presses it on all sides, and thrusts it out thorow a little hole in its middle; so it falls into the Orifice of the Tubes, which dilate sufficiently for its Passage into the Womb.

Some partly considering the close­ness of the Mouth of the Womb, and [Page 93]partly the thickness of the Membranes of the Ovaria and Ova, do judge it im­possible for the Seed to pass this way; therefore they think that it is taken up by the Veins which open in the Cavity of the Vagina and Matrix, where circulating, it ferments with the mass of Blood, from thence come all those Symptoms which appear in Con­ception: it enters and impregnates the Egg by the small twigs which are upon its Membranes. This Fermentation swells, the Membranes of the Tubae, opens the Cavity of the Womb, and makes every thing ready for the recep­tion of the Egg.

SECT. XVII. Of the Generation of the Foetus, of the Ʋmbilical Vessels, of the Placenta, of the Posture of the Foetus, and term of Delivery.

THere are two principal Opinions about Generation; the first is, that all the Parts of the Body were prae­existent in the Egg of the Female, and that Generation is nothing but the quickening and rendring the Embrye fit for the Nourishment and due Aug­mentation which it ought to have. The other is M. Leuenhoeck's, who, by his fine Microscopes, does discover a vast [Page 94]number of Animalcules in the Male Sperm; he says, that they have all the Shapes of our Body, and that they alone are sufficient for Generation▪ but Dr. Garden, with more reason, thinks that the Female Eggs are for a Nou­rishment to them; because, that Eggs are frequently found in the Tubae Fallo­pianae. Now the Egg being faln into the Womb, the Humours which [...] from the Extremities of the Vessels of the Womb, penetrating the Tunicl [...] of the Egg, swell and dilate it just [...] the Sap or the Earth swells Seed that is thrown into the Ground. Or the branches of the Veins and Arteries, whereby the Egg was tied in the Ova­rium (which may be probably the Um­bilical Vessels) being broken, fasten with the Vessels which open in the Cavity of the Womb: then there ap­pears a little Cloud upon the middle of the external Tunicle of the Egg, which Cloud is the beginning of the Placen [...]a, and about the same time the Spine of the Embry [...] appears, and a lit­tle after the Cerebrum and Cereb [...], which are like two small Bladd [...] afterwards the Face begins to form, and the Eyes stand goggling out of the Head; the Heart may be plainly seen beating; and last of all the Extre­mities appear.

Of the Cho­rion.Now the Membranes of the Foetus are the same with those of the Egg. The first, which is the External, is called Chorion; it is pretty thick, smooth on its inside, but rough and unequal on its outside. It receives some bran­ches from the Umbilical Vein and Ar­t [...]ries by which it is tied to the Pla­c [...]ta. It covers the Amnies or Inter­nal Membrane, and between them there is a Liquor, which is that Liquor which the Chorion imbibes first, when the Egg falls into the Womb, this Liquor de­creases as the Foetus increases: So that towards the last Month, the Chorion comes close to the Amnios,

Of the Am­nios.Which is the Second and Internal Membrane. It covers immediately the Foetus. It is whiter, thinner and smoo­ther than the Chorion. It contains a clear and pure Liquor, in the middle of which swims the Foetus. The first of this Liquor is originally in the Egg (as has been already said) but as soon as the Egg falls into the Womb, 'tis increas'd by the Liquor which the Cho­rion imbibes, which passes also thorow the Pores of the Amnios, till the Plae­cen [...]a is form'd, which adhering to the bottom of the Womb, intercepts this Liquor, and sends it by the Umbilical Vein, some of whose branches termi­nate in the Glands of the Amnios, where [Page 96]this Liquor is separated from the [...]est of the Blood which is carried back by the branches of the Umbilical Arteries which are spread upon the same Mem­brane.

Of the Allan­toides. Needham, Graaf, and Bidl [...]o, say that there is a third Membrane, called Al­lantoides. In Beasts it lies betwixt the Chorion and the Amnios. It is the Re­ceptacle of the Urine of the Foetus, which is brought from the Bladder in­to this Membrane by the Ʋrachus, which is one of the Umbilical Vessels; but it is not in a humane Foetus.

Of the Ʋmbi­lical Vessels.Now the Umbilical Vessels are four in number, counting the Ʋrachus, with the two Arteries, and the Umbilical Vein.

The Arteries rise from the Extre­mity of the Aorta, or the beginning of the Iliacks of the Foetus, and passing by the sides of the Bladder, they join the Ʋrachus at the Navel; thorow which they pass, then they give some branches to the Amnios and Chorion, and are afterwards divided into an in­finite number of branches in the Pla­conta. The Vein rises by several roots or branches which are spread thorow all the Substance of the Placenta; it pierces the Chorion and Amnios, to which it gives several twigs; and passing in at the Navel, it joins the [Page 97] Vena Porta, in the Substance of the Liver.

The Ʋrachus rises from the bottom of the Bladder, ends in the Allantoides, for discharging the Bladder of the U­rine, according to some (tho' we can­not perceive any visible Cavity in it.) Others with more reason, think that it ends in the Navel, for the sustaining the Bladder in its Situation, to hinder that it fall not upon its Orifice, which would necessitate the Urine to run out incessantly.

The Umbilical Vessels come all three out of the Body of the Foetus, wrapt up in one common Tunicle, which makes a rope, upon which there are several knots, which are nothing but the Vessels a little dilated in those places. There are some so foolish as to think, that the number of knots marks the number of Children that the Mother shall have during her life.

The Ʋse of the Ʋmbilical Vessels.The Use of the Umbilical Vessels, is to carry the Maternal Blood by the Veins to the Foetus for its nourish­ment; that which is unfit for this Use, is carried back by the Arteries to the Placenta, whilst the Foetus is still sup­plied with more by the Vein; so that there is a continual Circulation betwixt the Mother and the Foetus.

Of the Pla­centa.The Placenta is a glandulous Body fixed to the bottom of the Womb by several small Protuberances or Roots, it grows in proportion as the Foetus grows; it is of a circular Figure: at its biggest, 'tis two fingers thick, and six or seven in Diameter, its Concave side is smooth, its Convex by which it is tied to the Womb, is rough and unequal, there are as many of them as there are Foetus; the Umbilical Vessels terminate in it. The use of the Placenta is to separate and prepare, from the Arteries of the Womb, that part of the maternal Blood which is fittest for the nourishment of the Foetus, and to send back, by the Veins of the Womb, the Blood which is brought by the Umbilical Arteries.

Of the Posture of the Foetus.The Foetus is almost of an oval Fi­gure whilst it lies in the Womb, for its Head hangs down with its Chin upon its Breast; its Back is round, and turned opposite to its Mothers Back, with its Arms it embraces its Knees, which are drawn up to its Belly, and its Heels are close to its Buttocks, its Head upwards, and its Feet downwards. But about the ninth Month it changes its Posture, the weight of the Head makes it to tum­ble; so its Head falls down, its Feet get up, and its Face turns towards its Mothers Back; but because then it is [Page 99]an irksom, tho' favourable Posture for its Exit, the motion it makes for its relief, give frequent Pains to its Mo­ther, which causes a Contraction of the Womb for the Expulsion of the Foetus. When the Child presents in any other Posture, it should be carefully put back again, and if possible, turn'd to the right way, if that can't be done, it should be brought out by the Feet.

SECT. I. Of the Dugs.

HAving already described the Fi­gure, Bounds, and External Parts of the Thorax, we come now to examine the Substance and Use of its several Parts; amongst which, the first that presents it self is the Dugs.

The Dugs are like two Semispheres, situated upon the Pectoral Muscles, in the upper Part of the Chest, one on each side; they have each a small Pro­tuberance in their middle, called the [Page 100]Nipple, about which there is ordina­rily a darkish coloured circle, called Areola.

The Substance of the Dugs is com­posed of a great number of Glands of an oval Figure, of which some are much bigger than others; these Glands lie in a great quantity of Fat, of Veins, Ar­teries and Nerves, the Vessels make several Plexus's about them, and ter­minate also in them. They have each an Excretory Duct, which as they ap­proach the Nipple, join and unite to­gether, till at last they form 7, 8, or more small Pipes called Tubuli Lacti­feri, which have several cross Canals by which they communicate with one another, that if any one of them be stopt, the Milk which was brought to it might not stagnate, but pass thorow by the other Pipes, which all termi­nate in the Extremity of the Nipple.

The Nipple is made of a fibrous and spongious Substance, thorow which the Tubuli Lactiferi pass: It has several Nerves, Veins and Arteries which give it an exquisite sense, and a small ere­ction when it is handled.

The Dugs have Arteries and Veins called Mammariae, from the Subclavian Vessels; they have others also from the Thoracica Superior, which are spread chiefly in their External Substance: [Page 101]They have Nerves from the Vertebral Pairs, and from the sixth Part of the Brain.

The use of the Dugs is to separate the Milk for the Nourishment of the Foetus. The Arteries which terminate in the Glands, which compose the Sub­stance of the Dugs, bring the Blood pregnate with a Chyle which has recei­ved its last Perfection by its Circulation thorow the Lungs; this Chyle being separated by the Glands of the Dugs, runs thorow the Tubuli Lactiferi upon the Suction of the Child.

The Dugs in Men are very small, they are chiefly for an Ornament. I have seen some Men who have had Milk in them.

SECT. II. Of the Diaphragma, or Midriff.

UNder the Dugs lie the Muscles and Bones which compose the forepart of the Thorax; these are described in their proper Places; having therefore cut them up, and having laid the Ca­vity of the Thorax open, the Dia­phragma, Pleura, Mediastinum, Heart, and Lungs appear.

Of the two Muscles which compose the Midriff.The Diaphragma is composed of two Muscles, which divide the middle and lower Cavity. The First and Supe­riour [Page 102]Muscle is Circular, where it be­ginneth from the Sternum, and the last Ribs on each side, and ends in a Ten­don or Aponeurosis, which hath al­ways been taken for the nervous Part of the Midriff. The Second and Infe­riour Muscle comes from the Vertebrae of the Loins, by two Productions, of which that on the right side comes from the first, second, and third Ver­tebrae of the Loins; that on the left side is somewhat shorter, and both these Productions join and make the lower Part of the Midriff; which joins its Tendon with the Tendon of the other, so as that they make but one Mem­brane, or rather Partition.

The Midriff is covered with a Mem­brane, from the Pleura, on its upper side, and by the Peritonaeum on its lower side; it is pierced in its middle for the Passage of the Vena Cava; in its lower Part, for the Oesophagus; and the Nerves which go to the upper Ori­fice of the Stomach, and betwixt the Productions of the Inferiour Muscle passes the Aorta, the Thoracick Duct, and the Vena Azygos.

Of its Vessels.The Midriff receives Arteries and Veins called Phrenicae from the Cava and Aorta; and sometimes on its lower Part, two branches, from the Vena Adiposa, and two Arteries, from the [Page 103] Lumbares. It has two Nerves which come from the third Vertebrae of the Neck, which pass thorow the Cavity of the Thorax, and are dispersed in the Muscles of the Midriff. Some say, that these Diaphragmatick Nerves are the Organ of Laughter, of Weeping, of Sneezing, and of Singing, because of the Connexion they have with the Nerves, which go to the Muscles, which perform these Motions.

Of its Ʋse.The Midriff, in its natural Situation, is Convex on the upper side towards the Breast, and Concave on its lower side towards the Belly: therefore when its Fibres swell and contract, it must become plain on each side, and conse­quently the Cavity of the Breast is en­larged, to give liberty to the Lungs to receive the Air in the Inspiration; and the Stomach and Intestines are pressed for the distribution of the Chyle; but it diminishes the Cavity of the Breast, when it resumes its natural Situation, and presses the Lungs for the Expulsion of the Air in Expiration.

SECT. III. Of the Pleura, Mediastinum, and Thymus.

Of the Pleura.THE Pleura is a double Membrane, which covers all the Cavity of the Thorax, it arises from the Vertebrae of the Back, ascends on each side upon the Ribs, to the middle of the Sternum. It is fixed to the Periostium of the Ribs to the internal intercostal Muscles: and it covers the Midriff. Its side to­wards the Cavity is smooth and equal, but that which is fixed to the Ribs is rough. The Vessels which run betwixt its Duplicature, are Veins from Vena Azygos and upper intercostal Vein, Ar­teries from the Inferior and Superior intercostal Arteries, and Nerves from the twelfth Pair of the Back from the intercostal Pair, and from the eighth Pair.

Of the Media­stinum.The Mediastinum is a double Mem­brane, formed by the continuation of the Pleura; it comes from the Sternum, and goes straight down, thorow the middle of the Thorax to the Vertebrae, dividing the Cavity in two. It con­tains, in its doubling, the Heart, in its Pericardium, the Vena Cava, the Oeso­phagus, and the Stomachick Nerves. The Membranes of the Mediastinum [Page 105]are finer and thinner than the Pleura, and they have a little Fat. The Me­diastinum receives branches of Veins and Arteries from the Mammillary and Diaphragmatick, and one Proper, called Mediastina, its Nerves come from the Stomachick; it has also some Lym­phaticks which open in the Thoracick Duct. The Mediastinum divides the Thorax in two Parts, to the end that one Lobe of the Lungs may officiate, if the other be hindered by a Wound on the other side of the Thorax; it fixes the Heart in its Pericardium, and preserves them from external Injuries. Sometimes there is a matter contained betwixt its Membranes, immediately under the Sternum, which may occasion the Trepaning of this place.

Of the Thy­mus.The Thymus passes for a Conglome­rate Gland, a little softer than the Pan­creas, situated in the upper Part of the Thorax under the Claviculae, where the Cava and Aorta divide into the Sub­clavian branches. This Gland is big in Infants, but as they grow in Age, it grows less. It receives Veins and Ar­teries from the Jugulars, Nerves from the Par Vagum, and Lymphatick Ves­sels which discharge themselves in the Subclavian Vein.

The use that is commonly given to the Thymus, is to be a little Cushion, [Page 106]to support the Thoracick Duct, and to strengthen the Cava and Aorta, at their Divisions in the Subclavian Vessels, to defend them against the hardness of the Vertebrae: But 'tis probable that its principal use is to filtrate or separate some Liquor which is not yet known.

SECT. IV. Of the Pericardium, Heart, and its Parts.

Of the Peri­cardium.THE Pericardium is a thick Mem­brane of a Conick Figure, it res [...]m­bles a Purse, and contains the Heart in its Cavity. Its Basis is pierced in five places, for the Passage of the Vessels, which enter and come out of the heart; it is fixed to the Mediastinum, and to the Midriff. It receives its Vessels from the Axillaries and Phrenicae, Nerves from the recurrent and Diaphragma­tick. It has Lymphaticks, which dis­charge themselves in the Thoracick Duck. It defends the Heart from ex­ternal Injuries.

Of the Water contained in the Pericar­dium.In the bottom of the Pericardium there is a clear and sweet tasted Wa­ter, but in some, tinctured a little with Blood. It is found in abundance in the Pericardium of Women and Old Men, but there is little of it in those that are Hectick and Pleuritick. When it is in too great quantity, it causes a [Page 107]Palpitation of the Heart, and some­times Death.

Authors do not agree about the rise of this Water. Some say, that it comes from the Extremities of the Arteries; others, that it comes thorow the Sub­stance of the Heart, but it's more pro­bable that it is filtrated thorow the Glands, which are at the basis of the heart, and that it may not abound too much, nor putrify by standing too long, it is taken up by some small Glands which are in the Membrane of the Pe­ricardium, and from them carried by the Lymphaticks into the Thoracick Duct.

Of the Situa­tion, Figure and Connexion of the Heart.The Heart is situated in the middle of the Thorax, between the two Lobes of the Lungs, it is of a Conick Figure. Its basis is the upper end, and its Apex or Point is the lower end, which is turned a little to the left side; therefore its motion is best felt there. It is tied to the Mediastinum, to the Pericardium; and sustained by the great Vessels which bring and carry back the Blood. It is covered by a Membrane, which is the proper Membrane of the Muscles; its basis is always surrounded with Fat, in which there are some small Glands. Of its Vessels; It has two Veins, which come from the Cava, immediately before it opens in the Heart, and they are accompanied with two Arteries from the Aorta, [Page 108]which run thorow all the Substance of the Heart; they are called the Coronal Vessels. The Veins on the right side communicate, at their Extremity, with the Veins of the left. In like manner do the Arteries of each side communi­cate with one another; and it is the same almost in all the Parts of the Body. The Heart receives a multitude of small Nerves from the eighth Pair, particularly they creep in great num­bers about the Aorta, and on the left Ventricle. It has also some Lympha­ticks, which discharge themselves in the Thoracick Duct.

At the basis of the Heart, there are two Auriculae or little Ears, Of the Auri­culae. one on the right, the other on the left side. In the right Ear opens the Vena Cava, in the left the Vena Pulmonaria. The first discharges the Blood that it receives from the Cava into the right Ven­tricle; and the second thrusts the Blood that comes from the Vena Pul­monaria into the left Ventricle. Their Figure is like the triangle Ambligonium, the left is less, but thicker than the right. Their Substance is composed of two Orders of muscular Fibres, which terminate in the tendon in the basis of the Heart; and at the right Ear, there is a circle like to a tendon, where the Cava ends. Their external Surface is [Page 109]smooth; their internal is unequal, full of small fleshy Pillars, which send out small Fibres that cross and go thwart one another: and betwixt these Pillars there are as many furrows, which are more in the left, than in the right Ear; they receive Nerves from the branches of the eighth Pair. They have the same motions of Systole and Diastole as the Heart, which we shall explain after­wards. Their Ʋse. Their Use is to receive the Blood, which is brought by the Veins, and by them to be thrust into the Ven­tricles of the Heart.

Of the Ventri­cles of the Heart.In the Heart, there are two Cavities or Ventricles, which answer to the two Ears, one on each side; the sides of these Cavities are very unequal, full of Fibres and little fleshy Productions, long and round, of a different Figure and bigness, called Columnae or Pillars. Betwixt these Fibres, there are several furrows, in the sides of the Ventricles, especially in the left Ventricle, they are deeper and larger; they contribute much to the close contraction of the Ventricles. And because the side of the right Ventricle is much thinner than the left, therefore there are often two or three fleshy Fibres, which come from the middle Partition to its opposite side, to hinder it from dilating too much.

The right Ventricle seemeth wider [Page 110]than the left, which is longer and nar­rower than the right, and its sides stronger and thicker. The two Ven­tricles are separated by the Septum Me­dium, which is properly the inside of the left Ventricle, being its Fibres are continued with the Fibres of the oppo­site side of the same Ventricle. The Ves­sels which enter and come out of the Heart, are the Vena Cava, the Arteria and Vena Pulmonaria, and the Aorta or Arteria Magna.

Of the right Ventricle, and of its Valves.The right Ventricle receives the Blood from the Vena Cava, thorow the right Ear, and at the mouth of the Ventricle there are placed three Valves, made of a thin Membrane; they are of a triangu­lar Figure, and are called Tricuspides; their bases are fixed to the mouth of the Ventricle, and their Points tied by small Fibres to the fleshy Productions; so that when the Heart contracts, its Point approaches its basis, the fleshy Produ­ctions move upwards; therefore the Fibres of these Valves are relaxed, and the Valves lifted up by the Blood, which gets underneath them, because the furrows and fleshy Productions keeping the Valves at a little distance from the sides of the Ventricle, give way to the Blood to pass under them, and so to thrust up the Valves, which shut so closely the entry into the Ven­tricle, [Page 111]that the Blood cannot return the way it came in. But when the Ven­tricle is dilated, the Fibres are pulled down, and the Passage made open for the Blood to enter.

Of the Valves of the Arteria Pulmonaria.When the Heart contracts, the Valves being lifted up, the Blood in the right Ventricle finds an open Passage into the Arteria Pulmonaria, which rises imme­diately out of the right Ventricle; its Mouth is less than the Cava, it has three Valves called Segmoidales or Semi-lunares, because they resemble a Half-Moon or Segment of a circle; their Substance is membranous. When they separate, they give passage to the Blood, from the Ventricle into the Artery; but they shut the Passage, and are thrust together, by the Blood, if it endeavours to return.

Of the Valves of the left Ventricle.The Vena Pulmonaria discharges it self thorow the left Ear into the Ven­tricle of the same side. At the Orifice of this Ventricle there are two Valves called Mitrales, because when they are joined together, they resemble a Mitre, they are broader than the other Valves; they are situated, and have the same use as the Tricuspides in the right Ventricle.

Of the Valves of the Aorta.The Aorta or great Artery, rises im­mediately out of the left Ventricle; it has three Valves, which have the same Use and Figure as the Semi-lunares in the Arteria Pulmonaria.

Of the Sub­stance of the Heart, and of the order of its Fibres.The Heart is a compound Muscle; its Substance is made of Fibres of the same Nature as those of other Muscles; there are several Orders of them, which have different Directions, and all their Tendons are in the basis of the Heart. The First, or External Order is of Fi­bres, which surround the whole Heart; they go in an Oblique or Spiral Line from the left to the right, except on the Surface of the right side, some of its finest Fibres go in a straight Line from the basis to the Point. The Se­cond or next order surrounds also the whole heart, they have a contrary Di­rection, which is from the right to the left in an Oblique or Spiral Line. The next Orders are only proper to the left Ventricle. The first, which is on the external side of the Ventricle, goes in an Oblique Line from the left to the right. The second Order is on the inside, or that which makes the Septum Medium, or Partition Wall of the Ventricles; they go in an Oblique Line from the right to the left, and they are continued with the foregoing Fi­bres at the Point of the Heart.

All these Orders of Fibres come to­gether as to one common Centre at the Point of the Heart; But,

Obs. That all the Fibres of the same Order, do not always go from the basis [Page 113]to the Point; for some after they have gone about half way obliquely from the one side, turn up obliquely, and are inserted in the basis on the other side. Neither do all the Fibres in the same order keep together, for some in­termix with the Fibres of the next Order; so in separating these Orders many Fibres are broken. Some of the Fibres in the internal Orders, proper to the left Ventricle, terminate in the fleshy Productions of the same Ven­tricle. The Bone which is found in the basis of the Hearts of several Beasts, is nothing but the tendons of the Fibres of the Heart ossifyed: it is sometimes found in Men.

Of the Systole and Diastole of the Heart.This Muscle has two Motions, which they call Systole and Diastole. The Sy­stole is when the Fibres of the Heart contract, its Point approaches its basis, the Heart becomes short; its sides swell, and its Cavities are strongly pressed on all sides. The Diastole is when this Muscle ceaseth to act; its Fibres are lengthened; its Point re­tires from its basis; its sides fall, and its Cavities become large and wide.

Of the Circu­lation of the Blood thorow the Heart.Having described the Heart and its Parts, let us now consider the Circu­lation of the Blood, which is perfor­med by means of this Muscle, the Vena Cava Ascendens and Descendens unite in [Page 114]one, and open into the right Ear; where they unite, there is a little Protube­rance made by their Coats on the in­side of the Canal like an Isthmus, which directs the Blood both of the one and the other into the Ear, and so hinders them from rushing upon one another. The right Ear in its Diastole receives the Blood from the Vena Cava, which by its Systole is thrust into the right Ventricle; (for the tendinous Circle which is at the Mouth of the Cava con­tracts, and hinders the Blood to return into it,) which at the same time is in its Diastole; in the Systole of the right Ventricle the Blood is thrust into the Arteria Pulmonaria, (for it cannot re­turn into the Ear, because of the Val­vulae Tricuspides) which communicates with the Vena Pulmonaria, which car­ries back the Blood into the left Ear, which in its Systole, thrusts the Blood into the left Ventricle which is then in its Diastole. In the Systole of this Ven­tricle, the Blood is thrust into the Aorta; (for it cannot return into the Ear, because of the Valunlae Mitrales) which carries it thorow all the Body. Now the Aorta, when it comes out of the Heart, ascends a little upwards, and then turns downwards to form the descending Trunk, because the Blood might offend the Brain, if it [Page 115]ran with that impetuosity with which it's thrown out of the Heart; and from the upper side of this turning, the Cer­vical and Axillary Vessels do arise: by this artifice the Blood collides against the sides of the Aorta; its force is bro­ken; part of it is taken in by the Mouths of the ascending branches, but its greatest part is directed down­wards.

Of the Circu­lation of the Blood in the Foetus.Let us now consider which way the Blood circulates in the Foetus; for this you must observe, that in the right Ear, on the lower side of the Protu­berance of the Cava, just opposite to the Mouth of the Cava Descendens, there is a hole called the Foramen Ovale, which opens into the Vena Pulmonaria; this hole has a Valve, which suffers the Blood to enter the Vein, but hin­ders it to come back again. There is likewise a Passage or Canal called Ductus Bottali, which comes from the Trunk of the Arteria Pulmonaria, and goes to the Trunk of the Aorta.

Now the Blood which comes from the Placenta, by the Umbilical Vein into the Porta, is sent into the Cava, by a Canal, which goes straight from the Trunk of the Porta, to the Trunk of the Cava in the Liver. This ascends the Vena Cava, and is directly thrown thorow the Foramen Ovale, into the [Page 116] Vena Pulmonaria, which carries it into the left Ventricle, which throws it into the Aorta, to be distributed thorow all the Body. But the Blood which comes down the Vena Cava ascendens, is diver­ted by the Isthmus of the Cava, from the Foramen Ovale, and falls into the right Ventricle, which thrusts it into the Arteria Pulmonaria, from whence it's immediately carried by the Ductus Bottali into the Aorta, to be mixt with the rest of the Blood. By this you see, that the Blood which comes from the Vena Cava descendens, passes only thorow the left Ventricle, whilst the Blood which comes from the Cava as­cendens, passes only thorow the right Ventricle.

Thus having shewed what way and by what means the Blood circulates thorow the Heart; let us now reflect a little upon the quickness of its motion. Each Ventricle will at least contain an Ounce of Blood, and therefore we may safely suppose that the Heart throws into the Aorta, an Ounce of Blood every time it contracts. The Heart contracts 4000 times in one Hour, or sometimes more and sometimes less, according to the different Tempera­ments, Sexes and Ages: from which it follows, that there passes thorow the Heart every hour 4000 Ounces, [Page 117]or 350 Pound of Blood. Now the whole mass of Blood is but about 25 Pound; so that a quantity of Blood equal to the whole mass of Blood, passes thorow the Heart 14 times in one hour, which is about once every 4 minutes. I say, a quantity which is equal to the whole mass of Blood, and not the whole mass it self; for it is not to be sup­posed that the Blood which goes to the Extremities can return to the Heart as soon as the Blood which goes only to the Kidneys or Liver.

The Velocity and quantity of Blood, together with the time it takes to run in different Blood Vessels, differ accor­ding to the different lengths and ori­fices of the Vessels, according to the greater and lesser Compression the Ves­sels receive in the different Parts tho­row which they run, according to diffe­rent quantity of Secretions from the Vessels in the several Parts of the Body, according as the Vessels have more or less turnings and windings, and accor­ding as they divide into more of fewer branches. These things determinate the Velocity, Time, and Quantity of Blood in the several Vessels of the Body.

In the Blood there is much volatile Salt and Spirits, some Phlegm and Sulphur, a little Earth, but little or [Page 118]no fixt Salt. Alcali's dissolve it, and Acids coagulate it.

SECT. V. Of the Lungs.

Of the Figure of the Lungs.THE Lungs are in the middle of the Cavity of the Thorax; they are divi­ded into two Lobes by the Mediastinum; and the left is ordinarily subdivided into two more. The Figure of both Lobes together resemble a Cows foot, being a little concave betwixt the two Lobes, where they embrace the Heart, and behind, where they lie upon the Vertebrae; but before, where they touch the Sternum, and Ribs, they are Con­vex. The colour of the Lungs in a Foetus, is of a pale red, but after that the Air has once entered them, Of their Co­lour and Con­nexion. they lose their red, and remain always pale; yet in Adults they are variegated with the one and the other. They are tied to the Sternum by the Mediastinum before, to the Vertebrae by the Pleura behind, where it rises from the Ver­tebrae, to the Heart by the Vena and Arteria Pulmonaria, and sometimes to the Pleura, where it covers the Ribs particularly in the left side, and espe­cially after a Pleurisie.

Of the Mem­branes of the Lungs.The Lobes of the Lungs are covered with a double Membrane; the Exter­nal [Page 119]is smooth, fine, but close. The In­ternal is rough and unequal, formed by the Extremities of the Vessels and Membrance which tie the Vesicles toge­ther. It resembles the side of a Honey-Comb. Of the Stru­cture of the Lungs. Each Lobe is subdivided into an infinite number of little Lobes, dis­posed like so many Grapes, upon the Sides and Extremities of the branches of the Bronchiae, covered each with their proper Membrane, and tied toge­ther by a number of Membranes, which fill up the Spaces that these Lobes leave between one another. Each little Lobe contains an infinite number of small and little Orbicular Vesicles, which leave small Interstices between them, which are full of small Membranes, like those which tie the Lobes toge­ther. Each Vesicle receives a twig from the branch of the Brochiae that enters the Lobe in which they are con­tained: This twig opens in their Ca­vity, which is divided into little Cells which communicate with one another, and a twig from the Vein, Nerve, and Artery which are spread upon the Membranes of the Vesicle: each Vesicle communicates with one another.

Of the Vessels of the Lungs.Now the Vessels which enter the Lungs, are the Trachea or Aspera Ar­teria which comes from the Larynx, the Arteria Pulmonaria, which comes from [Page 120]the right Ventricle, and Vena Pulmonaria which comes from the left Ear of the Heart; each of these divides into two branches, for the two great Lobes of the Lungs, which being accompanied with the branches, from the eighth Pair of Nerves, they divide into as many bran­ches as there are little Lobes in the Lungs. Where-ever there is a branch of the Trachea there, there is a branch of the Nerve, Vein, and Artery; and the Trachea is always in the middle. The branches of the Trachea Arteria, which are ordinarily called Bronchiae, open in the Cavity of the Vesicles, and the Nerves, Veins, and Arteries, form Plexus's upon the Membranes of the Vesicles; the Arteries open into the Veins by an Anastomosis. Besides these, the Lungs have Lymphaticks, which discharge themselves into the Thora­cick Duct, accompanying the Vein, and they are chiefly to be seen in the External Part of the Lungs. There is also a Vein which comes from the Cava that Sommichellius calls Pneumo­nica, and an Artery that M. Ruysh calls Arteria Bronchialis, which comes from the Aorta: The Artery brings the Blood for the Nourishment of the Substance of the Lungs, and the Vein carries back what is superfluous.

Of the Tra­chea Arteria.This is the passage of the Vessels thorow the Lungs; but because the Trachea Ar­teria has a particular Structure, it de­mands a particular Examination. It is a Canal situated in the forepart of the Neck, before the Oesophagus; it descends from the Larynx to the fourth Vertebrae of the Back, where it divides, and enters the Lungs, and its branches are afterwards called Bronchiae. Of its Carti­lages. This Canal is made of Annular Cartilages, which are at small and equal distances from one another. These Cartilages the nearer they are to the Larynx the bigger they are and the further they are from it, the smaller they are; and those of the Bronchiae are so close to one another, that, in expiration, the second enters within the first, and the third within the second, and so the following always enters the preceeding. Betwixt the La­rynx and the Lungs these Cartilages make not compleat rings, but their hind part, which is contiguous to the Oesophagus is membranous, that they may the better contract and dilate, and give way to the Aliments as they go down the Oesophagus: but the Car­tilages in the Bronchiae are compleatly Annular; only the Extremities of the Bronchiae, a little before they open into the Vesicles, have no Cartilages, [Page 122]but instead of them they have small circular Ligaments, which contract and dilate for the reception and expulsion of the Air.

Of its Mem­branes.These Cartilages are tied together by two Membranes, the one external, and the other internal. The external is composed of circular Fibres; it covers the whole Trachea externally. The in­ternal is of an exquisite sense, it covers the Cartilages internally. It is com­posed of three distinct Membranes. The First is woven of two Orders of Fibres. Those of the first Order are Longitu­dinal, for the shortening the Trachea; they make the Cartilages approach and enter one another. The other Order is of circular Fibres, for the contracting the Cartilages. When these two Or­ders of Fibres act, they help, with the external Membrane, in Expiration, in Coughing, and in the Excretion of any tickling humour. The second Mem­brane is altogether glandulous; and the Excretory Vessels of these Glands open in the Cavity of the Trachea; they separate a Liquor for the moisten­ing the Cavity, and for defending it from the Acrimony of the Air. The third and last is a Net of Veins, Nerves, and Arteries. The Veins come from the Vena Cava; the Nerves from the Recurrent, and the Arteries from the Carotides.

Of the use of the Lungs.Having thus considered the Structure of the Lungs, 'tis evident that the Air enters by the Trachea into the Vesicles, and so swells and dilates the Substance of the Lungs in Inspiration; but in Expiration these Vesicles contract, and thrust out the Air, which carries a great deal of excrementitious Vapours from the Blood along with it, by the Ela­sticity of their Fibres, by the help of the Nerves, and by the pressure of the surrounding Bodies employed in respi­ration. It is also evident, that the Blood is carried from the Heart by the Arteria Pulmonaria, thorow all the Sub­stance of the Lungs, and that the same Blood is taken up by the Vena Pulmo­naria, and carried back again to the Heart. And we are sure, that whilst the Blood passes thorow the Lungs, that it receives some alteration; for the Blood in the Arteria Pulmonaria is of a dark colour, as venal Blood; but that which is in the Vein is of a florid red, as Arterial Blood; yet how this Alteration is made is not deter­mined by Anatomists.

Some considering that the Surface of venal Blood, drawn in a Pellet and exposed to the Air, turns to the colour of Arterial Blood; do think that the nitrous Particles of the Air which we breath, passes thorow the Tunicles of [Page 124]the Vessels, and mixes with the Blood, and causes this Alteration, which they say is necessary for the recruiting of the Animal Spirits, and for the entertain­ing the natural heat of the Blood, by fermenting with the Sulphureous Parts of the Aliments.

Others explain this Alteration only by the beating and agitation of the Air upon the bloody Vessels of the Lungs, which indeed is sufficient to cause this Alteration; and the necessity of this beating appears by an Expe­riment, which is this; take a little new drawn Blood, look to it imme­diately thorow a Microscope, you shall see a number of small, red glo­bules, swimming in a thin and clear Liquor; and the longer you look, the more of these Globules join in one, and the bigger they grow, till at last they all come into one, and the Liquor is separated by its self, and then the Blood is coagulated.

Thus the red Globules of the Blood in the Veins as they return from the Extremities, grow bigger and bigger, for the want of being agitated: And if they were not separated and broken into many smaller Particles, they would soon cause a stagnation in the Capil­lary Vessels. So the beating of the Air in Inspiration and Expiration is [Page 125]necessary for the attenuating, subtili­zing, and intimately mixing the Chyle, Lympha, and other Parts of the Blood.

SECT. VI. Of the Larynx.

Its Situation.THE upper Part of the Trachea Ar­teria, is called the Larynx. It is almost of a circular Figure, lying be­low the root of the Tongue before the Pharynx. It is composed of five Cartilages, which sometimes in old Men become as hard as Bones.

Of the Carti­lago Scuti­formis.The first is the [...] or Scuti­formis, because of its Figure. It makes that Protuberance in the forepart of the Larynx called Pomum Adami. It has four Corners. It is about an inch broad, but not so long. It's Concave within, and Convex without. It is divided in the middle by a Line from its upper to its lower Part; its four Angles have each a small Production; the two upper, which are longer, are tied to the Horns of the Os Hyoides, and the two lower to the second Car­tilage, which is called [...], Of the Annu­laris. or An­nularis, because it resembles a ring: It's very large and thick behind, which Part is like the Stone of a Ring; it's situated below the other Cartilages of the Larynx. They stand upon it as [Page 126]upon a basis, and by it they are tied to the Trachea.

Of the Arytae­noides.The Third and Fourth are called [...]—they reach from the mid­dle of the Concave side of the Thy­roides to the upper, and back part of the Annularis; and they make that chink or Rimula, which is the Mouth of the Larynx, called Glottis. Betwixt those and the sides of the Thyroides there are two small Cavities on each side, formed by the Muscles and Mem­branes which join them together; in which, if a little drink or bread fall, as sometimes happens, when one laughs or speaks in eating or drinking, it cau­ses a violent Cough, and a great tick­ling.

Of the Epi­glottis,The Fifth and last Cartilage, is the Epiglottis; it's of a softer Substance than the others; it resembles a little Tongue; it is tied by its basis to the upper and middle Part of the Con­cave side of the Thyroides; its use is to cover the Glottis in eating and drink­ing; for the Aliments by their weight press it close down upon the Glottis, and they pass over, without entering the Larynx, into the Oesophagus: but when the Aliments are past, the Epi­glottis, by its natural resort, which is common to all Cartilages, lifts up a­gain, and gives way to the Air for the [Page 127]Respiration. When we Speak or Laugh, the Glottis must necessarily be open for the Passage of the Air; therefore it is not convenient to speak whilst we are Eating or Drinking.

Of the Muscles of the Larynx.The Larynx has two Pair of com­mon Muscles, and four Pair proper.

The First of the Common Muscles is the Sternothyroidaeus; Sternothy­roidaeus. it arises from the upper Part of the inside of the Ster­num, and ascending on the sides of the Trachea Arteria, it is inserted to the lower Part of the sides of the Carti­lago Scutiformis: when these Muscles act, they pull this Cartilage down­wards.

The Second is the Hyothyroidaeus; Hyothyroi­daeus. it arises from the lower Part of the Os Hyoides, and descending is inserted to the lower Part of the Scutiformis near the former. They pull up the Larynx.

The First of the proper Muscles is the Cricothyroidaeus; Cricothyroi­daeus. it ariseth from the forepart of the Cartilage Cricoi­des, and running under the Thyroides, it is inserted into the inside of that Cartilage.

The Second is the Cricoarytaenoidaeus; Cricoarytae­noidaeus. it ariseth from the lateral Part of the Cricoides, and ascending is inserted to the lateral Part of the Arytaenoides; this dilates the Arytaenoides. I see no reason [Page 128]for dividing this Muscle in two, as Mr. Cooper has done.

The Third is the Thyro-Arytaenoidaeus; Thyro-Ary­taenoidaeus. it ariseth from the internal and Con­cave side of the Scutiformis, and is in­serted to the foreparts of the Arytae­noides; it contracts the Rimula.

The Fourth Muscle is the Arytaenoi­daeus; Arytaenoi­daeus. it runneth upon the upper Part of the Cartilage Arytaenoides, and with its fellow, forms a Sphincter for con­tracting of the Rimula.

A true Squinzie which is caused by the Inflammation of these Muscles, is Mortal; because they shut exactly the chink of the Larynx; therefore Bron­chotomy is absolutely necessary in this case, but it is rarely, tho' it may be safely used.

Of the Vessels of the Larynx.The Larynx receives Veins from the Jugulars, Arteries from the Carotides, and Nerves from the Recurrent.

Of the Glan­dulae Thy­roidaeae.On the lower Part of the Larynx, upon the sides of the Annulary Carti­lage, and of the first ring of the Tra­chea, there are two Glands called Thy­roidaeae; they are big and spongeous, of the figure of a Pear, their colour is red; their Substance solid and vis­cous; they have Veins, Nerves and Ar­teries as the Larynx; they have also some Lymphaticks.

Their Use is to separate a Serosity from the blood; this Serosity is depri­ved of its Acrimony by the Fat which is about the Glands, and it is after­wards sent thorow their Excretory Ves­sels into the Cavity of the Larynx, for the moistening it, and for facilitating the Motion of the Cartilages.

SECTION I. Of the Frontal and Occipital Muscles; and of the Pericranium.

THE Head is situated in the up­per Part of the Body, not on­ly for the conveniency of the Senses, but also that the Brain may the more easily send the Animal Spirits to all the Parts of the Body.

Its Natural Figure is round, but a little flat upon its Sides; round, that it might contain the greater quantity of Brains; and flat upon its Sides, that the bounds of the Sight may be the larger, or rather that the Ears might not be too much exposed to danger.

We have divided the external Parts of the Head into two, the Face and the hairy Scalp; we shall now divide it into the Containing and the Con­tained Parts. The Containing Parts are the Skin with the Hair upon it, the Pericranium, the Skull, and the two Meninges. Of the Skin and Hair we have already spoken; of the Skull we shall speak in its proper place.

Anatomists do generally say, that the Skull is covered both with a Peri­cranium and a Periosteum, but they have taken the Aponeurosis of the Oc­cipital and Frontal Muscles for one of them. These Muscles lie immediately under the Skin. The first two are cal­led Frontales. Their fleshy Fibres are insertedinto the Eye-brows, from thence they go straight up the Os frontis, and are continued by a long and large Aponeurosis to that of the Occipitales; they adhere closely to the Skin of the Forehead, which they pull upwards. The other two Muscles, which are cal­led Occipitales, have their fleshy Fibres fixed to the Skin of the Hind-head, which they also pull upwards: They are short, broad, and thin, and they end in a large Aponeurosis, which joins that of the Frontals, and both together cover the whole Skull.

Of the Peri­cranium.Therefore the Periosteum or Peri­cranium, is a very thin and nervous Membrane, of an exquisite sense, which covers immediately not only the Cra­nium, but all the Bones of the Body except the Teeth, and Bones of the Ear. It is tied to the Dura Mater, by some Fibres which pass thorow the Sutures of the Skull. It receives Veins from the external Jugulars, Arteries from the Carotides, Nerves from the fifth Pair of the Brain, and from the second of the Neck.

SECT. II. Of the Dura and Pia Mater.

THE Membranes or Meninges, which are within the Cranium are two, the Dura Mater, and the Pia Mater; so called, because they are supposed to be the Origination of all the Mem­branes of the Body.

Of the Dura Mater.The Dura Mater is a strong and thick Membrane, which covers all the Cavity of the Cranium, it contains the whole Brain somewhat loosely, that the Vessels which run between its Dupli­cature, and upon the Surface of the Brain, be not too much press'd by the Cranium; it sticks very close to the basis of the Cranium, and to its Su­tures by the Fibres and Vessels it sends [Page 132]to the Pericranium; it is fastened to the Pia Mater, and to the Brain, by the Vessels which pass from the one to the other. It gives a Coat or Covering to all the Nerves which rise from the Brain, to the Spinalis Medulla, and to all the Nerves which rise from it. Its Surface is rough towards the Cranium, but smooth towards the Brain. It is a double Membrane woven of strong Fibres, which may be plainly seen on its inside, but very hardly on its out­side next the Cranium.

Of its Pro­cesses.The Dura Mater hath three Pro­cesses made by the doubling of its inner Membrane. The First rises by a nar­row beginning from the Crista Galli to which it is fastened, and as it ap­proaches the hindhead it grows broa­der and broader, till it terminate where the Longitudinal Sinus ends. It divides the Cerebrum into two Hemispheres as deep as the Corpus Callosum. It resem­bles a Sickle, therefore it is called Falx. The Second separates the Cerebrum from the Cerebellum down to the Me­dulla Oblongata, that the weight of the Cerebrum may not offend the Cerebel­lum which lies under it. This Process is very strong and thick, and in rave­nous Beasts 'tis for the most part bony, because of the violent motion of their Brain. The Third is the smallest; it [Page 133]separates the external Substance of the hindpart of the Cerebellum into two Protuberances; and upon it Mons. Du Venney's fifth Sinus runs.

Of the Sinus's of the Dura Mater.In the Dura Mater there are several Sinus's or Channels, which run be­tween its external and internal Mem­brane; of these there are four prin­cipal ones, which are commonly de­scribed.

First of the Longitudi­nalis.The First is the Sinus Longitudinalis, it rises from the blind hole in the up­per Part of the Crista Galli; it runs along the upper Part of the Falx, and ends where it ends; it lies exactly under the Sutura Sagittalis. Into this Sinus, the Veins of the Brain, and some of the proper Veins of the Dura Mater bring back the Blood which they receive from the Arteries. Of these Veins, some running obliquely, from the forepart of the Brain back­wards, and others contrary, from the hindpart forward, creep a little space between the Duplicature of the Mem­brane, as the Ureters do upon the Bladder, and so they open in the Sinus. In this Sinus there are several small Cells and round Ligaments, which go from one side of the Cavity to the other. These by their Elasticity retard or further the Motion of the Blood.

The Second and Third Sinus's, Laterales. which this Sinus pours into, are the Laterales; they rise from the end of the first into which they open, and going down upon the sides of the Oc­cipital Bone, in a crooked way, they pass thorow the same hole, with the eighth Pair of Nerves, and discharge themselves into the internal Jugulars: into these Sinus's some Veins and the other Sinus's discharge themselves. Of the Fourth Sinus.

The Fourth Sinus runs upon the broad Extremity of the Falx, and opens where the Lateral Sinus's join the Lon­gitudinal. This meeting of the four Sinus's is called Torcular. It receives the Blood at its other Extremity, from a Vein of the Plexus Choroides.

Besides these, there are Six more, which have been described by several Anatomists. Of the Sinus Superiores. The first two are called Superiores, they rise from the hinder Processes of the Sella Turcica, or from the circular Sinus's of Doctor Ridley, and run along the upper Part of the internal Processes of the Os Petrosum, then descending they open into the Laterales.

Of the Infe­riores.There are two more called Inferiores; they rise from the same place with the other two, and running upon the Union of the Os Petrosum with the Occipital, they open into the Late­rales, [Page 135]just as they are going out of the Skull.

A fifth Sinus.There is a Fifth, which the curious M. Du Verney demonstrates; it runs upon the third Process of the Dura Mater, and divides into two branches, of which one opens into the Laterales, and the other into the Sinus Vertebrales. The exact Anatomist Doctor Ridley, Of the Cir­cular Sinus. in his Treatise of the Brain, gives ac­count of a Sixth, which he calls the Circular Sinus, because it surrounds the Glandula Pituitaria; it commu­nicates with the two Superiores and Inferiores.

Of three other Sinus's. Vezal hath remarked a Sinus which runs along the bottom of the Falx, and which opens into the Fourth Si­nus; this is called by M. Du Verney, Lon­gitudinalis Inferior. There are two more situated at the second Process of the Dura Mater, one on each side; they are about an inch wide from the Late­rales into which they open; but these three do not always appear.

The Ʋse of the Sinus's.The Use of these Sinus's is to receive the Blood of the adjacent Parts from the Veins, to which they are as so many Trunks, which discharge the Blood into the internal Jugulars.

Of the Vessels of the Dura Mater.The Vessels of the Dura Mater, are first a branch from the Carotidals, whilst it is in its long Canal, which [Page 136]is dispersed in the fore and lower Part of the Dura Mater. Secondly, An Artery with a branch of the internal Jugular Vein, which enter the hole of the Cranium, called Foramen Arteriae Durae Matris; they are dispersed on the sides of the Membrane, and run as high as the Sinus Longitudinalis. Thirdly, a branch of the Vertebral Ar­tery, and Vein which passes thorow that hole, where the Lateral Sinus's join the Jugulars, they are dispersed in the hind part of the Dura Mater.

The Blood which is brought by the Arteries, is carried back by the Veins which go out at the same holes by which the Arteries enter; but in case the swelling of the Arteries, by a pre­ternatural Fermentation of the Blood, should compress the Veins as they go out of the Skull, which might easily happen, being it has more Arteries than Veins; therefore there are seve­ral other Veins, which inosculate with the Arteries, and which carry the Blood from them into two small Veins, which are on the sides of the Longitudinal Sinus; 'tis these Veins which open into this Sinus, that the Blood, which was stopt the other way, may have a free Circulation this way, as has been ingeniously observed by Dr. Ridley.

It hath also Nerves from the first branch of the fifth Pair, which give it an exquisite sense. It has a motion of Systole and Diastole, which is caused by the Arteries which enter the Skull. No doubt the great number of Arteries in the Brain contribute more to it, than those few proper to it self, which may assist a little, tho' not very sensibly, because of their smallness and paucity. The use of the Dura Mater, is to con­tain and cover the Brain, the Spinal Marrow, and all the Nerves, to divide the Cerebrum in two, and to hinder it from pressing the Cerebellum.

Of the Pia mater.The Pia Mater is a thin and delicate double Membrane which lies under the Dura Mater, & covers immediately the Substance of the Brain; its inner Mem­brane is much larger than its outer Membrane, for it runs in betwixt all the Foldings and Circumvolutions of the Brain, to separate them, and to sustain the Blood-Vessels which make several turnings and windings upon it, before they terminate in the Substance of the Brain. It has proper Veins and Arteries, and the same use as the Dura Mater.

SECT. III. Of the Cerebrum and Cerebellum.

The Brains di­vided in two.THE whole Substance of the Brains is divided into two Parts, that which lies mostly in the forepart of the Skull is properly called the Cere­brum, and that which lies in the back Part, under the hind Part of the Ce­rebrum (which is supported by the second Process of the Dura Mater) is called the Cerebellum. Both the one and the other are contained in the Me­ninges and in the Cranium, as in a case of Bones, that nothing may hurt their Substance, which is soft.

Of the Figure and Substance of the Cere­brum.The Cerebrum is of a round Figure, it is divided down to the Corpus Callo­sum, by the first Process of the Dura Mater into the right and left side. Its external Surface resembles the turnings and windings of the Intestines. In the Cerebrum we distinguish two different Substances, the external which is of an ashy colour, and the internal which is of a white colour. Its external Sub­stance is called Substantia Corticalis or Cineritia; it is soft, glandulous, and of the colour of ashes. Its internal called Substantia Medullaris is firmer, white, and fibrous; of it the Nerves are made, and it reaches to the Extre­mity [Page 139]of the Medulla Spinalis, where it divides into Fibres.

The external Substance of the Brain, by its Circumvolutions, resembles the small Guts, and in the middle of each Circumvolution is the beginning of the Medullary Substance; so that the Cor­tical Substance is always on the exter­nal side.

Malpighius, who has examined this Cortical Substance, says, that it is no­thing but a heap of little Oval Glands, which receive the Capillary branches of the Veins and Arteries which belong to the Brain, and which send out an infinite number of Fibres, which all together make up the Medullary Sub­stance, which going out of the Cranium, forms the Nerves and Medulla Spinalis contained in the Vertebrae.

A general Idea of the Structure of the Brain.The internal Substance of the right and left side of the Brain coming to join one another, leave a space between them, which forms the three Ventri­cles of the Cerebrum, the upper Part or Covering of this space is called the Corpus Callosum; the bottom of this space is the internal Substance of the two sides of the Cerebrum, gathered to­gether as it were in two bundles, which are called Crura medullae Oblongatae, up­on them are the Protuberances called the Corpora Striata, and the Thalami [Page 140]Nervorum Opticorum. These Crura uni­ting, make one Body called the Me­dulla Oblongata, upon which there are four Prominences called Nates and Testes: And behind these Prominen­ces, the internal or medullary Substance of the Cerebellum, being also divided into two bundles, form upon each side of the Medulla Oblongata, three more Protuberances, and then it passes out of the Cranium into the Vertebrae, where it gets the name of Medulla Spi­nalis. This is a general Idea of the Structure of the Brain, for the better understanding its Parts. Which we shall now describe in particular.

Below the Cortical Substance, the first thing that appears is the Corpus Callosum, it lies immediately under the first Process of the Dura Mater, it is the Covering of the two lateral Ven­tricles, formed by the Union of the Medullary Fibres of each side.

Of the two Ventricles.This being laid aside, the two late­ral Ventricles appear, they reach from the forepart of the Cerebrum back­wards; they are pretty broad in their hind Part; but they grow narrower towards their fore Part. They are di­vided into the right and left Ventricle by a thin transparent Membrane, which comes from the under side of the Cor­pus Callosum, and is extended to the [Page 141] Fornix, which is in the bottom of the Ventricles; Of the Sep­tum Medium. this Membrane is called Septum Lucidum. I am apt to think it is a Production of the Pia Mater, which covers all the sides of these Ven­tricles.

In these two Ventricles there are four Prominences, two in each Ven­tricle. The foremost two are called Corpora Striata, Of the Corpo­ra Striata. which are the tips of the Crura Medullae Oblongatae. They are oblong, and their Extremities come down upon the sides of the two other Prominences; they are of a cineritious colour without, but in their internal Substance there are many white streaks which are the Medullary Substance mixed with the cineritious or glan­dulous. They are as it were tied to­gether by a Medullary Process, called by Vicussius, Commissura crassioris nervi Aemula.

Of the Thal. Nerv. Optic.The two other Prominences are called Thalami Nervorum Opticorum, because the Optick Nerves rise out of them; they are Medullary without, but a little cineritious within; they are of an oblong Figure; they are upon the upper Part of the Crura Me­dullae Oblongatae: between them there is a Medullary Tract, which encom­passes them, called by Willis, Limbi Posteriores Corporum Striatorum. Upon [Page 142]them also lies the Plexus Choroides, Of the Plexus Choroides. made of Veins, Arteries, and little Glands. The Learned Dr. Ridley, says he has seen Lymphaticks rise from it. This Plexus reaches from one lateral Ventricle to the other, passing under the Fornix, above the third Ventricle. It sends a branch to the fourth S [...]ul of the Dura Mater.

Of the FornixIn the middle above the Corpora Stri­ata and the Th. Nerv. Opt. there lies a thin and broad Production of the Me­dullary Substance, which comes from the fore Part of the Ventricles by two Roots, and reaches to the hinder Part, where it ends by two other Protube­rances called its Crura, which cover a great part of the Thalami Nerv. Optic. This Production is called the Fornix, because it is a Covering to the third Ventricle.

Of the third Ventricle.Under the Fornix there is a Rima between the Crura Medullae Oblongatae, which is the third Ventricle, it being a little dilated in its forepart, there is a hole that goes down to the Glan­dula Pituitaria; this hole is the entry to the infundibulum or Funnel, Of the Infun­dibulum. so called because of its Figure. It is a small Con­duit made of the Medullary Substance, covered with the Pia Mater; it pierces the Dura Mater upon the basis of the Skull, and sinks into the Substance of

Of the Glan­dula Pituita­ria.The Glandula Pituitaria, which is situated in the Sella Turcica, closely covered with the Pia and Dura Mater; it is of a harder Substance than the other Glands of the Body; it receives the end of the Infundibulum, which is supposed to carry a Liquor from the Ventricles into this Gland.

Of the Rete Mirabile.The Rete Mirabile is situated round this Gland; it is composed of Nerves from the fifth Pair, of Veins from the internal Jugulars, and Arteries from the Carotides and Cervical. It was commonly thought to be only in Beasts, but Dr. Ridley has discovered it also in Man, tho' it be less in him than in other Creatures. Its use is said to be to discharge the Serosity of the Blood, (which might hinder the Pro­duction of fine Animal Spirits) into the Glandula Pituitaria, which cannot be, because the Blood which is separate from this Serosity, goes not to the Brains, but is carried back immediately by the Veins.

Of the Anus.But to return to the third Ventricle, in its hinder Part there is another small hole called Anus, which leads into the fourth Ventricle in the Cerebellum. In the upper Part of this hole is situated the Glandula Pinealis, Glandula Pi­nealis. Des Cartes pre­tended Seat of the Soul, about the big­ness of a Pease, and seems to have [Page 144]the same use as other Glands; it is tied by some Fibres to the

Of the Nates. Nates, which are two Prominences of the Medulla Oblongata, situated a­bove the fore-part of that Conduit, which leads from the Anus to the fourth Ventricle; they are of an Oval Figure, pretty big, and immediately behind them are two other Promi­nences of the same Figure and Sub­stance called Testes both covered with a Net of Blood-Vessels. Testes. There is a small transverse Medullary Protube­rance behind the Testes, from which the Pathetick Nerves rise.

The Conduit which reaches from the Anus to the fourth Ventricle, Note: placne="marg" Isthmus. is in that Part of the Medulla Oblongata▪ which is betwixt the Cerebrum and the Cerebellum, called the Isthmus. The upper Part or Cover of this Conduit, which is betwixt the Testes and the foremost vermicular Process of the Cerebellum, to which two it is tied at its two ends, and to the Processes that come from the Cerebellum to the Testes, Valvula ma­jor. at its sides, is called Valvula Major; 'tis of a Medullary Substance [...] its use is to keep the Lympha from falling out above the Nerves in th [...] basis of the Skull. These are all the Parts belonging to the Cerebrum.

Of the Cere­bellum.Now the Cerebellum which is much less, is also composed of a Cortical and Medullary Substance; its Superficies makes not turnings and windings as that of the Cerebrum; but its foldings are straight, and they resemble the Seg­ments of Circles, or the edges of Plates laid on one another; and these Seg­ments are largest in its middle, and they grow less as they approach its fore and hind Part, where they seem to re­semble too Worms; Processus Vermifor­mes. therefore called Processus Vermiformes.

The Medullary Substance of the Ce­rebellum, as it approaches the Medulla Oblongata, gathers together, and then divides equally into two bundles, which are joined to the two sides of the Me­dulla Oblongata; as they separate, they leave a little space upon the upper side of the Medulla, which is called the Fourth Ventricle, and its further end, Of the fourth Ventricle. because of its resemblance, Calamus Scriptorius. The top of this Ventricle is covered with several Blood-Vessels woven like a Net.

Of the Pro­cesses of the Cerebellum.The Medullary Substance of the Ce­rebellum makes three Processes upon each side of the Medulla Oblongata. The first two go on each side of it to the Testes; the Valvula Major is betwixt them. The second two are pretty broad; they go straight down on each [Page 146]side, and meet on the under side of the Medulla; they make that Protube­rance called Processus Annularis; Processus An­nularis. and the Third goes backwards upon the upper sides of the Medulla; they make it look bigger, being like two Cords upon its sides.

This is all that is remarkable in the Cerebrum, Cerebellum, and upper side of the Medulla Oblongata. But if you turn over the Brain, you may see di­stinctly the rise of all the Nerves, the Infundibulum, the Crura Medullae Ob­longatae, one on each side of the Cere­brum: where they join you may see the Processus Annularis; and beyond that there are two Prominences called Cor­pora Pyramidalia; Corpora Py­ramidalia and Olivaria. they are about an inch long; and on each side of them, towards their lower end, there are two more, which, because of their figure, are called Corpora Olivaria, and then the Medulla Oblongata goes out of the Skull, being contained in the Pia and Dura Mater.

Observe that the Medulla Ob­longata, with all the Protuberances which are upon its upper and lower sides are not purely of the Medullary Substance, but internally they are mix'd with the Cortical; and it is this mix­ture which makes that they call Striae, to which they have given different [Page 147]imaginary Uses, according to their dif­ferent Positions.

Now the Vessels of the Brains are Nerves, Veins and Arteries. The Nerves are ten Pair. The first Pair, are the Olfactory Nerves; they rise from the basis of the Corpora Striata, and pass thorow the holes of the Os Cribriforme. The second Pair are the Optick Nerves; they rise partly from the Extremities of the Corpora Striata, and partly from the Thalami Nervorum Opticorum, which they almost embrace; they unite to­gether above the Cella Turcica, and im­mediately dividing again, they pass thorow the two foremost holes in the Os Sphaenoides. The third Pair are Mo­vers of the Eyes; they rise on each side of the Infundibulum from the Medulla Oblongata, and go out at the Foramina Lacera. The fourth Pair are the Pa­thetick Nerves; they rise from the small Medullary Cord which is be­hind the Testes, and pass thorow the Foramina Lacera. The fifth Pair rise from the fore Part of the Processus An­nularis; they give Nerves to the Dura Mater; each of them divides into three branches; the first passes out at the Foramen Lacerum, the second at the third hole of the Os Sphaenoides, and the third thorow another hole of the same Bone. The sixth Pair rises from [Page 148]the sides of the Processus Annularis, and goes out at the Foramen Lacerum, but just before it goes out, it casts back a branch, which makes the root of the Intercostal Nerve; this goes out at the Canal thorow which the Carotidale Artery enters. The seventh is the Au­ditory Nerve, it rises from the hind Part of the Processus Annularis, and enters the hole in the Process of the Os Petrosum. The eighth Pair is the Par Vagum, it rises from the Medulla Oblongata behind the Processus Annula­ris by three several Threads which join in one, and it goes out at the same hole the lateral Sinus's open into the Jugulares. The ninth Pair rises from the Processus Olivares of the Medulla Oblongata, and passes out at a hole in the Occipital Bone, which is proper to its self. The tenth and last Pair rises by several Fibres from the begin­ning of the Medulla Spinalis, from thence ascending within the Occiput, it turns and passes out at the same hole thorow which the Vertebral Artery enters, between the first Vertebra and the Occipital Bone, running thorow a Sinus in this Vertebra. These are the Nerves of the Brain, which we shall trace further in the Eighth Chapter.

Of the Vesse [...] of the Brain.The Arteries are the two internal Carotidals which pass thorow two ob­lique Canals in the Ossa Petrosa; as soon as they enter the Skull, they give a branch which enters the Orbit of the Eye; they give branches which make the Rete Mirabile, then they pierce the Dura Mater on each side of the Infun­dibulum; they communicate with the Cervical Artery, and they give bran­ches to the Plexus Choroides, and are distributed thorow all the Substance of the Brain: their branches make many turnings and windings upon the Pia Mater, and at last are lost in the little Glands of the Cortical Substance of the Brain.

The two Vertebral Arteries which come out of the holes in the transverse Processes of the Vertebrae, enter the large hole of the Occipital Bone; they pierce the Dura Mater, and go along the under side of the Medulla Oblon­gata; then they cast back two bran­ches for the Spinal Arteries, and at the Processus Annularis they join in one branch called the Cervical Artery. This communicates with the two Carotides, by two branches called the Communi­cant branches; then it divides again into two, which give branches to the Rete Mirabile, Plexus Choroides, and they are afterwards distributed thorow [Page 150]all the Substance of the Brain, ending in the Cineritious Substance as the Ca­rotidales.

The Veins enter not the Cranium at the same holes that the Arteries do, because, as Dr. Ridley rightly observes, upon any Fermentation of the Blood, the Swelling and Pulse of the Arteries would compress the Veins against the bony sides of their Passage, and so cause a Stagnation and Extravasation of the Blood in the Brain, which would be the destruction of the whole Machine. Neither do the Veins run along by the sides of the Arteries in the Brain, as they do thorow all the rest of the Bo­dy, but they rise from the Extremities of the Arteries, in the Cineritious Sub­stance of the Brain, and go streight to discharge themselves into the Sinus's of the Dura Mater.

The Ʋse of the Brain.The Blood which is brought into the Brain by the Carotidal and Verte­bral Arteries, is separated by the Glands, which make the Cineritious and Corti­cal Substance of the Brain, from its finest and most subtile Parts, which they call Animal Spirits, which are received from the Glands by the Fi­bres of the Medullary Substance which is the beginning of the Nerves; the Blood which remains, is taken up by the Veins which are the branches of [Page 151]the Sinus's, which discharge themselves in the Lateral Sinus's, which pour the Blood into the internal Jugulars to be carried back to the Heart.

This is all the use we know of the Brain in General. As to the particular Use of its Parts, the Seat of the Soul, of the Memory, the Imagination, and the Judgment that Authors have so wittily determin'd, I am apt to think that it was more Fancy than Judgment that determined them to think so. We shall speak of the Medulla Spinalis, in the Third Section of the Eighth Chapter.

SECT. IV. Of the Eyes.

THE Organs of Sight are divided into two Parts; The internal Part which is the Globe or Body of the Eye, and the external Part, which is those Parts about the Globe subservient to the Globe.

Of the Eye-brows.The first of these last are the Eye-brows, which are nothing but some Hairs bunching out above the Eye, by some Fat which is under the Skin in this place. They break the Rays of Light that they be not directly darted into the Eyes, which would greatly offend the Sight, as they do [Page 152]when we look directly upon the Sun.

Eye lids.The next are the Eye-lids, two to each Eye. The upper Lid moves very quickly, the under very undis­cernibly.

Its Muscles.The upper Eye-lid is lifted up by the Musculus Rectus, which rises from the bottom of the Orbit of the Eye, where the Optick Nerves pierce the Cranium, and passing above the Mus­culus Superbus, 'tis inserted by a large tendon to the border of the Eye-lid.

Both Lids are brought together to shut upon the Eye by another Muscle called Orbicularis. It rises from the great Angle of the Eye, and its Fi­bres are spread two fingers breadth, covering the under Lid, they reach to the little Canthus, from which conti­nuing its circular Fibres which cover the upper Lid, it is inserted into the same place from which it arose. Some Au­thors divide this Muscle into two, the Superior and Inferior, which they make to rise from the great Canthus, and to be inserted into the little Canthus.

Of the Con­junctiva.The Eye-lids are covered within with a smooth Membrane called Conjunctiva, because it is continued upon the fore­part of the Globe, constituting that which we call the white of the Eye; it joins the Globe to the Edges of the Orbit.

Of the Cilia.The edges of the Eye-lids have two small and soft Cartilages, like the Seg­ments of a Circle, called Cilia; they keep the Eye-lids extended, that every Part may be equally raised. Upon them there is a rank of small Glands, whose excretory Channels open upon the edges of the Lids. They yield a wax which fasteneth the Eye-lids to­gether whilst we sleep. They are co­vered with the Skin externally, and with the Conjunctiva internally. Upon the edges of the Lids, there are also some hairs in form of a Pallisado, to preserve the Eyes, as the Eye-brows do, and to hinder any filth or flies from falling into the Eyes.

Of the Glan­dula Lachty­malis.In the backside of the Conjunctiva, upon the upper Part of the Globe is the Glandula Lachrymalis, pretty large, divided into several Lobes, each of which send out an Excretory Channel, which opens in the foreside of this Membrane, where it covers the upper Lid. This Gland separates the Matter of the Tears, which by the continual motion of this Lid, moisten the Cornea, which otherwise would dry and wrin­kle by the continual action of the ex­ternal Air.

Puncta La­chrymalia.In the great Canthus of each Eye, there are two holes called Puncta La­chrymalia; they are the two Orifices [Page 154]of the Lachrymal Sack, which is situ­ated in this corner, upon the Os La­chrymale; from the bottom of which there goes a small Pipe, which pierces this Bone into the Nose, and opens under the upper Lamina of the Os Spongiosum. It moistens the inner Mem­brane of the Nostrils, by the humour of the Lachrymal Gland, which runs from off the Globe into them. Some­times the Acrimony of this humour causeth sneezing, which we hinder, by pressing the Angle of the Eye, and so stop its running.

Between these two Puncta there is a Caruncle which serves to keep them open when the Eyes are shut. This Caruncle was thought to be the Glan­dula Lachrymalis.

Of the Muscles of the Eye.The Globe of the Eye is moved by four straight Muscles, and two oblique; and betwixt them there is a great deal of Fat, which facilitates the motion of the Globe.

The first of the four straight Muscles is called Attollens or Superbus; it lies upon the upper Part of the Globe; it pulleth up the Eye when we look up. The second is called Deprimens or Hu­milis; it pulleth down the Eye. The third is called Adductor, it draweth the Eye towards the Note. The fourth Abductor, it draweth the Eye towards [Page 155]the little Canthus. They rise all four from the Circumference of the hole in the Orbit, thorow which the Optick Nerves pass, and they terminate about the Cornea, by four pretty large Ten­dons: When they all act together, they draw the Eye towards the bottom of the Orbit. When the Superbus and the Adductor, or the Abductor act toge­ther, or the Humilis and the Adductor, or Abductor act together, they perform the Oblique Motions, which have been attributed to the Oblique Muscles.

The first of the Oblique Muscles, which is the fifth of the Eye, is the Obliquus Minor; it rises from the lower side of the Orbit near its external Circumference, where the first and se­cond Bones of the upper Jaw join to­gether, and ascending obliquely by the upper corner of the Eye, 'tis inserted to the upper and external side of the Globe, behind the Tendon of the Ab­ductor.

The second of the Oblique Muscles and sixth of the Eye, is the Obliquus Major; it rises from the bottom of the Orbit, and marching obliquely towards the great Canthus, in the up­per Part of which, near the brink, there is a Cartilaginous ring, thorow which it passes its round Tendon, from whence reverting backwards, it's inser­ted [Page 156]into the upper Part of the Globe, behind the Tendon of the Attollens.

The Use of the first of these Muscles is to draw the Globe of the Eye for­wards, and to turn its Pupil upwards; and of the second, to draw it forwards, and to turn its Pupil downwards, for the better receiving of the rays of light, which could not be performed by any of the other four Muscles; as Mr. Cooper has very well observed. And both of them are an Axis for suspen­ding the Globe, by which, in its al­most continual motion, 'tis moved the more easily; as has been ingeniously observed by M. De la Hire.

Now the Globe of the Eye is of a Sphaerical Figure; in it are contained the principal Instruments of Vision; 'tis composed of Coats and Humours.

Of the Con­junctiva.The first Coat is the Conjunctiva; it makes the white of the Eye; it hath been already described; it is full of small Veins and Arteries, which appear big in an Ophthalmia or Inflammation of the Eyes.

The second is called Sclerotica; Sclerotica. 'tis thick, hard, and smooth, opake be­hind, but transparent before, where it makes the

Third Coat called Cornea, Cornea. because it is transparent, like the Horn of a Lan­tern, in the fore-part of the Eye, which [Page 157]is surrounded by the white of the Eye: It is a little more Convex than the other Coats, bunching out more fore­wardly than the Conjunctiva.

The fourth is the Choroides; Choroides. it lies under the Sclerotica; 'tis much thinner than it; it hath a great number of Blood and Lymphatick Vessels which come from the second, and which are spread upon it, as also several Glands which separate from the Blood-Vessels, a black Liquor, which tinctures all this Membrane internally, which is other­wise of a whitish colour. This Coat is open, or has a hole before, for the passage of the rays of light, called Pupilla; that Part of this Coat which makes the Circumference of this hole, and which lies upon the sides of the Chrystalline humour, is

The fifth Coat called Ʋvea, Uvea. which is made of circular and straight Fi­bres; it contracts and dilates according to the different impressions of light and of Objects.

The Iris is that Part of the Ʋvea where the different colours appear. Iris. On the inside of the Ʋvea, from its Circumference, rises the Ligamentum Ciliare. It is made of Fibres which spread themselves upon the sides of the Chrystalline Humour, like Lines drawn from the Circumference to the Centre. [Page 158]These Fibres, by their Contraction and Dilatation, press the Chrystalline Hu­mour backwards, forwards, and change its situation, according as the distance of Objects require.

The sixth is the Retina, Retina. so called, because it resembles a Net, which co­vereth the bottom of the Cavity of the Eye; 'tis nothing but an Expan­sion of the Medullary Substance of the Optick Nerves; 'tis on this Coat that the impressions of Objects are made.

Of the Aque­ous Humour.The Humours of the Eye are three. The first is called the Aqueous; it lies in the forepart of the Globe, imme­diately under the Cornea, which it makes to bunch out a little, that it may receive the rays, which come di­rectly and obliquely from the Object; this Humour is thin and liquid, of a spirituous Nature; for it shall not freeze in the greatest Frost, and a great part of it evaporates some days after Death, when it receives no new supply. This evinces the necessity of a conti­nual supply for this Humour, which in effect it hath: for if the Cornea be pricked, and this Humour squeezed out, it shall be restored again in the space of ten or twelve Hours, by an Aqueous Duct, which rises from that branch of the Carotide Artery which goes to the Eye, and creeping upon [Page 159]the Tunica Sclerotica, it pierces the Globe near the Pupilla, where it pours out at several Orifices, its spirituous Li­quor.

Chrystalline Humour.The second Humour is the Chry­stalline; it lies immediately next to the Aqueous, under the Ʋvea, opposite to the Pupilla, nearer to the forepart, than the back part of the Globe; it is the least of the Humours, but much more solid than any of them; its Figure, which is Convex on both sides, re­sembles two unequal Segments of Spheres, of which the most Convex is its back side, which makes a small Cavity in the Glassy Humour in which it lies. It is covered with a fine Coat called Aranea, and the Fibres of the Ligamentum Ciliare are spread upon its sides.

Of the vitri­ous Humour.The third is the Glassy Humour; it hath a great resemblance to the white of an Egg; it filleth all the hind part of the Cavity of the Globe. It is in a greater abundance than the other two. It is thicker than the Aqueous, but thinner than the Chrystalline Hu­mour. It is contained in a very fine Coat of the same Name. It gives the Spherical Figure to the Eye. Upon its back part the Retina is spread, which it holdeth from the Chrystalline Humour at a distance, re­quisite [Page 160]to receive the impression of Objects distinctly.

Of the Vessels of the Eyes.The Vessels of the Eyes are Veins and Arteries from the external Caro­tide and Jugular, which are distributed upon the external Parts of the Eyes, and a Vein from the superior Sinus of the Dura Mater, in the basis of the Skull, and an Artery from the inter­nal Carotidale. They accompany the Optick Nerves, and are distributed on the Muscles and Globe of the Eye.

There are also some Lymphaticks which accompany the Vessels. The Nerves of the Eyes are,

Of their Nerves.The Optick Nerves; they are pretty big and round; they pierce the Globe of the Eye; and their Medullary Fi­bres are expanded upon the hind part of the Glassy Humour, which Expan­sion is called the Retina.

The third Pair of the Brain called Motorii; The fourth Pair called Pa­thetici, the first branch of the fifth Pair called Ophthalmicus, and the sixth Pair are all bestowed upon the Muscles of the Eyes.

Of Vision.All the Rays which come from one Point of an Object are, by the Chry­stalline Humour, united in a Point of the Retina; which is in a straight Line, drawn from the same Point of the Ob­ject, thorow the Centre of the Chrystal­line [Page 161]Humour; and consequently all the Rays, which come from all the Points of an Object, are, by the Chrystalline Humour, united in the Retina, in the same Order and Proportion, as the Points of the Object are from whence these Rays come. Therefore the im­pression which these Rays make upon the Retina, must be the Image of the Object.

Thus in general, Vision is Perfor­med. But now let us see what the other Parts of the Globe conduce in this Action. We have said, that the Cornea was more Convex than any other Part of the Globe, by which means, all the Rays are gathered to pass thorow the Pupilla, and none of them are lost upon the Ʋvea.

How the Parts of the Eye contribute to it.The Aqueous Humour being the thin­est and most liquid, easily changes its figure, by which means the Globe is rendered more or less Spherical, accor­ding as the distance of the Objects re­quire.

The straight Fibres of the Ʋvea di­late the Pupilla, when there are but few Rays of Light, and the circular Fibres contract it when there are two many. The Ligamentum Ciliare presses the Chrystalline Humour nearer to the Retina, when Objects are at a greater distance from the Eye; for Rays, from [Page 162]a nearer Object, unite at a greater di­stance behind the Chrystalline Humour, and Rays, from a more remote, at a lesser. The Glassy Humour keeps the Chrystalline Humour at such a distance from the Retina, as is necessary for uni­ting the Rays, which come from one Point of the Object, exactly in one Point of the Retina.

The impression of the Object is made upon the Retina. The Choroides is tinctured black, that the Rays of Light which pass thorow the Retina, may not be reflected back again, to confuse the Image of the Object.

Being distinct, Vision consists in the union of all the Rays which come from one Point of an Object exactly in one Point of the Retina; and that the Rays which come from Objects at different distances, are united at different di­stances, behind the Chrystalline Hu­mour; they cannot both be united exactly upon the Retina; therefore the Eye cannot see equally distinctly at the same time Objects at different di­stances. It is for this reason that the Globe of the Eye moves so quickly, and almost continually, and that the Muscles of the Eyes have such a great quantity of Nerves to perform their motion.

When the Globe of the Eye is flat, as happens sometimes in old Age, that the Rays, if produced, should pass the Retina before they unite, in such a case there is no distinct Vision, and such as have this defect, are called Presbitae. And if contrary, the Globe of the Eye be so Convex as to unite the Rays be­fore they come to the Retina, then there is no distinct Vision neither; and such as have this defect are called Myopes.

SECT. V. Of the Ear.

Of the Exter­nal Ear.THE Ear is divided into the Exter­nal and Internal. The External Ear (whose Parts have already been described) is composed of the Skin, a Cartilage, and a little Fat. The Skin of this Part is thin and smooth, it sticks close to the Cartilage by means of a fine Membrane. The Cartilage is in that Part of the External Ear called the Pinna; and the Fat in that Part called the Lobe. The Vessels of the External Ear, are Veins from the Ju­gulares, Arteries from the Carotidale, and Nerves from the Portio Dura, and second Pair of the Neck.

The External Ear is tied to the Os Petrosum, by a strong Ligament, which comes from the backside of the Pinna, [Page 164]tho' the Ear has but a very obscure Motion, yet it has two Muscles. The first arises from the outside of the fron­tal Muscle, where it joins the Crotaphite, and is inserted into the upper and back part of the Pinna. The second arises from the upper and foremost part of the Processus Mammillaris, and is inser­ted into the middle and back part of the Concha. The first draws the Ear upwards, and the second draws it down­wards and backwards. The use of the External Ear is to gather the Sounds, and to carry them to the Internal. Its Inequalities and Circles do moderate the violence of the Air.

Of the Meatus Auditorius.The Internal Ear begins at the Con­duit which goes from the middle of the Concha to the Tympanum; it is cal­led Meatus Auditorius. It is Cartila­ginous from the Concha till within a little of the Tympanum, where it is Bony. It is crooked, running first up­wards, and then downwards to the Tympanum. It is about an inch long. It is slit on its upper side towards the Temple. It is covered within by a pretty thick Membrane. Betwixt this Membrane and the Cartilage, especi­ally where it is slit, there are a great number of little Glands, whose Ex­cretory Channels piercing this Mem­brane, carry a yellow sort of Excre­ment [Page 165]into the Meatus, which hinders Insects, or any other thing, to enter the Ear.

Of the Tym­panum.At the further Extremity of this Conduit, there is a thin transparent Membrane stretched out like the Head of a Drum, upon a bony Circle, only in its upper Part it's loose and not tied to it. The handle of the Malleolus is tied to this Membrane, and there runs a small twig of a Nerve from the fifth Pair upon its inside, called Chorda Tym­pani. This Membrane is properly the Partition between the External and Internal Ear. It is called Tympanum.

Of the Barrel.Behind this Membrane there is a pretty large Cavity called the Barrel; It is about three or four lines deep, and five or six wide. It is lined with a fine Membrane, on which there are several Veins and Arteries. It is al­ways full of a purulent Matter in Chil­dren. In this Cavity there are four small solid Bones, not covered with a Periosteum, as the rest of the Bones of the Body are.

Of the Mal­leolus.The first is the Malleolus or Ham­mer, so called, because of its shape. Its Head has on its lower side two Pro­tuberances and a Cavity whereby it's joined to the Incus by Ginglimus; its handle, which is pretty long and small, is fastened to the Tympanum. Near its [Page 166]Head it has two small Processes, into which there are two Muscles inserted.

Its Muscles.The first is called the Externus; it arises from the upper and external side of the Meatus Auditorius, and is in­serted into the upper and longer Process of the Malleolus: This Muscle pulleth up the Head of the Malleolus, so its handle falls lower, and consequently the Tympanum is relaxed. This is ne­cessary when sounds are too great, which might break the Tympanum.

The second is called the Internus; it arises from the Extremity of the Con­duit which goes to the Mouth. It lies in a small Channel made in the Os Pe­trosum, and is inserted into the lower and lesser Process of the Hammer. When this Muscle acteth, the head of the Hammer is pulled down, its handle lifting up, and consequently the Tym­panum distended, which is necessary when the Sounds are low.

The second small Bone is called In­cus, Incus. the Anvil. It has a Head and two Legs. Its Head has a Protuberance and two Cavities, whereby it is articulate with the Hammer; the shorter of its Legs is tied to the side of that Con­duit which goes to the Processus Mam­millaris, and its longer Leg to the Head of the third Bone called,

Of the Stapes.The Stapes or Stirrop, because of its [Page 167]resemblance. 'Tis of a triangular Fi­gure, being made of two branches set upon a flat basis, which stands upon the Foramen Ovale. The space between the two branches is filled up by a fine transparent Membrane; the union of the two branches is called the Head of the Stirrop, in which there is a small Cavity, in which lies the fourth Bone. There is a small Muscle which arises out of a small Channel in the bottom of the Barrel, and which is inserted into the Head of the Stirrop.

Of the Os Orbiculare.The Os Orbiculare, which is a very small Bone, being convex on that side which is received in the Cavity of the Head of the Stirrop, and hollow on the other side, where it receives the long Leg of the Anvil, which is only joined to the Stirrop, by means of this fourth Bone.

Of the holes in the Barrel.Besides these Bones, there are several holes in the Barrel. The first is in its forepart nearest the Tympanum. It is the entry to the Sinus in the Mammillary Process. The second is the Orifice of a Conduit which opens behind the Pa­late of the Mouth. The beginning of this Conduit is bony, and its Extre­mity which is near the Ʋvula, is Mem­branous. Part of the Air which we breath enters by this Conduit into the Ear. The third and fourth are at the [Page 168]further end of the Barrel opposite to the Tympanum. The one is called Fe­nestra Ovalis. The basis of the Stirrop stands upon it. It is the entry to the Vestibulum. The other is called Fe­nestra Rotunda. It is covered by a fine Membrane, inchased in a rift of this hole. It leads to the Cochlea.

Of the Vesti­bulum.The Vestibulum is a Cavity in the Os Petrosum, behind the Fenestra Ovalis, it is covered with a fine Membrane; in it open the Semicircular Pipes of the Labyrinth. The upper turning of the Cochlea, and the Auditory Nerve pier­ces into it also.

Of the Laby­rinth.The Labyrinth is made of three Se­micircular Pipes excavated in the Os Petrosum; they open by five Orifices into the Vestibulum. That which is called the Superior Pipe, joins one of its Extremities with one of the Extre­mities of that which is called the In­ferior Pipe, and these two Extremi­ties open by one Orifice, but the mid­dle Pipe opens at each end by its self into the Vestibulum.

Of the Co­chlea.The last Cavity of the Ear is the Cochlea; it resembles a Snail's Shell. Its Canal which winds in a Spiral Line is divided in two, the upper and lower by a thin Lamina Spiralis. The upper Part of this Lamina is membranous, where there are several holes, thorow [Page 169]which twigs of the Auditory Nerve pass from the one Canal to the other. The upper Canal opens into the Vesti­bulum, and the lower into the Barrel by the Fenestra Rotunda.

Of the Vessels of the Ear.The Vessels of the internal Ear are Arteries and Veins from the internal Carotidale and Jugulars. The Nervus Auditorius enters by the hole in the upper Part of the Os Petrosum. It divides into two branches, of which one is hard, the other soft. Its Portio Mollis is distributed thorow all the Cochlea and Labyrinth, and the Portio Dura is bestowed on the external Parts about the Ear.

Of Hearing.A Sound is nothing but a certain Refraction or Modulation of the ex­ternal Air, which being gathered by the external Ear, passes thorow the Meatus Auditorius, and beats upon the Tympanum, which moves the four lit­tle Bones in the Barrel; in like man­ner as it is beat by the external Air, these little Bones move the internal Air which is in the Barrel and Vesti­bulum: which internal Air makes an impression upon the Auditory Nerve in the Labyrinth and Cochlea, accor­dingly as it is moved by the little Bones in the Barrel; so that according to the various Refractions of the ex­ternal Air, the internal Air makes [Page 170]various impressions upon the Auditory Nerve, the immediate Organ of hear­ing; these different impressions represent different Sounds.

SECT. VI. Of the Nose.

Of the exter­nal Nose.THE Nose may be divided into two Parts, the External and Internal. The External Nose is covered with the Skin and some Muscles, of which after­wards. Its upper Part consists of two Bones closely joined together, on their upper side. Its lower Part is made of four Cartilages, of which the first two are fixed to the lower ends of the fore­said Bones; they are also joined toge­ther on the upper side; they are pret­ty broad, and as they approach the tip of the Nose they grow thinner and foster. The other two lie upon the lower ends of the first two, to which they are tied by a Membrane; They are called Narium Alae.

The Cavity made by these Bones and four Cartilages is divided in its middle into two Nostrils, by a Parti­tion, of which the upper end is bony, the lower end Cartilaginous; the fleshy Extremity of this Cartilage is called Columna.

The upper end of each side of this Cavity divides into two, of which one goes up to the Os Spongiosum, the other goes down into the Fauces, and opens behind the Palate, by which means we breath thorow our Nostrils. At the lower end of this Cavity, there are two small holes which pierce the Bone of the Palate and open in one behind the Dentes Incisivi; they carry the thin Rheum of the Nostrils into the Mouth.

This Cavity is covered by a pretty thick and glandulous Membrane; its Glands separate that Matter which we call Mucus into the Nostrils. On the lower end of this Membrane, there grow several Hairs called Vibrissi; they with the Mucus which the Glands se­parate, stop any filth from ascending too deep into the Nostrils.

Of the inter­nal Nose.By the internal Part of the Nose, we understand the immediate Organ of Smelling; it lies in the upper Part of the Cavity of the Nostrils, it is made of the Os Cribriforme and its Pro­ductions, the Os Spongiosum, of which each Lamina is covered with a fine Membrane, upon which the Fibres of the Olfactory Nerve, which pass tho­row the holes of the Os Cribriforme, and the Fibres of the first branch of the fifth Pair, which come from the Orbit are spread.

In this Membrane there are many small Glands which separate an humour which moistens it, and stops the Ex­halations of odoriferous Bodies, which make their impression upon the Ol­factory Nerves which are spread upon it. Grey hounds and other Beasts which have a more exquisite smell than Men, have also many more Laminae covered with such a Membrane.

Of the Con­duits which open in the Nose.There are several Conduits which open between these Laminae. The first and second are the Ductus Lachrymales, of which we have spoken before. The third and fourth come from the Sinus Frontales. The fifth and sixth come from the Sinus's of the second Bone of the upper Jaw. The seventh and eight come from the Cells of the Os Spongiosum, they pierce the Membrane which covers the first or uppermost Lamina; And the ninth and tenth come from the Sinus in the Os Sphae­noides. All these Conduits carry the Liquor, which is separate in their Ca­vities into the Nostrils, for the moi­stening its Membranes, which otherwise would dry too much by the Air which we breath thorow our Nostrils.

Of the Vessels of the Nose.The Vessels of the Nose are Arteries from the Carotidals which pass with the Olfactory Nerve, they are distri­buted in the internal Nose; the exter­nal [Page 173]Carotidal and Jugular, and the second branch of the fifth Pair give Arteries, Veins, and Nerves to the external Nose. Some give an account why the smell of Bodies, which consist of acrimonious Parts, draw tears from the Eyes, and why the want of Taste does ordinarily accompany the want of Smelling, by the communication of the branches of the fifth Pair of Nerves which are distributed thorow these three Senses.

SECT. VII. Of the Mouth and Tongue.

THE Parts of the Mouth are the Lips, the Gums, the Palate, the Ʋvula, and the surrounding Glands.

Of the Lips and Gums.The Lips are made up of several Muscles, of which afterwards. Their use is to shut the Mouth, and to arti­culate the Voice.

The Gums are a hard sort of Flesh formed by the union of two Mem­branes, one of which is a Production of the Periosteum, and the other of the internal Membrane of the Mouth: They are set about the Teeth, to keep them firm in their Sockets.

Of the Palate.The Palate or Roof of the Mouth is covered with a pretty thick Mem­brane which is continued to the Ton­sils; [Page 174]upon it there are a great number of little Glands whose Excretory Ducts piercing it like a Sieve, discharge a Li­quor for the moistening and dissolving of the Aliments. It is an Error to think that the Palate tastes, for by it it's impossible to distinguish the most acrid Substances.

Of the Uvula and its Mus­cles.The Ʋvula is a Reduplicature or Pro­duction of the internal Membrane of the Mouth; its Substance is very lax, and it has a number of small Glands as in the Palate: It is somewhat long, of a Conick Figure; it hangs from the Roof of the Mouth near the Passage which comes from the Nose, above the the seat of the Larynx between the Tonsils. It is moved by two Pair of Muscles, which are

The Pterigostaphilinus Externus; it arises fleshy from a small Protuberance, upon the under side of the Body of the Os Sphaenoides, and goes directly to be inserted into the hind Part of the Ʋvula.

The Pterigostaphilinus Internus arises from the same Protuberance of the Os Sphaenoides, and growing into a small round Tendon, which passes over a small Process, like a hook, of the Pro­cessus Pterigoidaeus, from thence revert­ing, it's inserted into the forepart of the Ʋvula.

When the first of these Muscles act­eth, it pulleth the Ʋvula backwards; when the second contracteth, it pulleth the Ʋvula forwards, because of the Pulley thorow which its Tendon pas­ses, which alters the direction of its Motion; both which Motions are ne­cessary for articulating the Voice, and in deglutition, that nothing may re­gurgitate into the Nose which we take by the Mouth.

Of the Paro­tides.The Glands, which are the sources of the Spittle, which discharges it self into the Mouth, are in great number, of which the principal are the Paro­tides, one on each side, situated under the Ear, above the Musculus Masseter; they are of the Conglomerate sort, be­ing made up of a great number of smaller Glands; each of which sends out a small Excretory Duct, and they all unite and form one Channel called Ductus Salivalis Superior, which run­ning over the Cheeks, pierces the Buc­cinator, and opens in the Mouth; when the Masseter acteth in Mastication, it presses the Saliva into the Mouth.

Of the Maxil­lares.The Maxillares which are situated within the under Jaw, one in each side, are also of the Conglomerate sort; the Excretory Pipes of their small Glands unite, and form two Ducts, which both together open under the [Page 176]tip of the Tongue, on the inside of the Dentes Incisivi, where they have each a small Papilla at their Orifice. When the Muscles of the Tongue or lower Jaw act, they compress these Glands.

Of the Sub­linguales.The Sublinguales are one on each side of the Tongue; they have two Excre­tory Ducts as the former, formed by the Union of that of each small Gland; they run on each side of the Tongue, near its tip, where they open into the Mouth at a little distance from the Gums; when the Mylohyoidaeus acteth, it compresses them.

Of the Ton­sillae.The Tonsillae or Almonds appear also two, one on each side of the Ʋvula, tho' really they are continued to one another, under the common Membrane of the Mouth, with which they are covered; each of them hath a large Oval Sinus, which opens into the Mouth, and in it there are a great number of lesser ones, which discharge themselves thorow the great Sinus of a mucous and slippy Matter into the Fauces, Larynx, and Oesophagus, for the moistening and lubricating these Parts; when the Muscle Oesophagus act­eth, it compresseth the Tonsillae.

Besides these, there are a great num­ber of little Glands spread upon the Cheeks and Lips, whose Excretory Channels open into the Mouth; and [Page 177]all of them separate the Saliva or Spit­tle, which conduces in the dissolution of the Aliments.

The Tongue is connected in the Mouth to the Os Hyoides, to the La­rynx, and by a membranous Ligament which is in the middle of its lower side. Sometimes this Ligament is con­tinued to the tip of the Tongue, and then it hindereth Children from Sucking; therefore in such a case it should be cut.

Of the Mem­branes and Papillae of the Tongue.The Tongue is covered with two Membranes. The External hath upon its upper Part, and particularly to­wards the tip of the Tongue, a great number of Papillae, of a Pyramidal Figure; they stand not up straight, but incline towards the basis of the Tongue; they appear not so plainly in Men as in Brutes, in some of which last they grow Cartilaginous. Each Papilla has a small root, which makes a small hole in the viscous Substance, which lies be­tween the two Membranes. In Men the chief use of these Papillae Pyrami­dales seems to be for preserving the Papillae Nervosae, which are of a softer Substance, that they be not hurt by the hardness or roughness of the Ali­ments: And in Beasts, which feed upon Grass, which they gather toge­ther with their Tongue, these Pa­pillae [Page 178]are like so many Hooks for the grasping, cutting, and pulling of the Grass; and perhaps by their roughness rubbing upon the Palate, they con­duce to press the Spittle out of the Glands.

Under the External Membrane there lies a thin viscous Substance which is white, on that side next the External Membrane, and black on that side next the Internal. When the Tongue is boiled, this Substance hardens, and is like a Searce being full of small holes, made by the roots of the Papillae Pyra­midales.

The Internal Membrane is thin and soft; upon it there appear several Papillae made of the Extremities of the Nerves of the Tongue, therefore they are cal­led Nervosae: They are situated upon the sides of the Tongue, but chiefly towards its tip; they resemble the small Horns of a Snail; for their Ex­tremities are round and bigger than the rest of their Bodies. The Extre­mity of each Papilla pierces the Exter­nal Membrane of the Tongue. They quit those holes, and remain on the In­ternal Membrane, when the External is raised. These Papillae are the imme­diate Organ of Tasting.

Of its Sub­stance.The Substance of the Tongue is mus­culous, being made of Plans of Fibres of different Directions.

The first or External Plan is made of straight Fibres, which surround the Tongue, reaching from its Basis to its Point; when they contract they shor­ten the Tongue. Under them there are several Plans of Fibres, which run from one edge of the Tongue to the other; they draw the edges of the Tongue together. There are also seve­ral Plans of Fibres, which run from the under to the upper side of the Tongue; when they contract, they make the Tongue broad and thin. These two sorts of Fibres cross one another at right Angles, and they lie Stratum super Stratum, from the tip of the Tongue to its basis; first a Plan of one sort, and then a Plan of the other sort. There is some Fat betwixt these Fibres, but chiefly towards the basis of the Tongue.

Of its Vessels.The Vessels of the Tongue are Veins from the Jugulars called Ranulares. It has Arteries from the Carotidals, and Nerves from the fifth and ninth Pair.

Of its Mus­cles.The Muscles of the Tongue are three Pair.

The Styloglossus; it arises fleshy from the Processus Styloides, from thence de­scending, it is inserted into the root of the Tongue; it draws the Tongue up­wards.

The second Pair is the Genioglossus; it arises from the inside of the forepart of the lower Jaw, and is inserted into the root of the Tongue; it pulls the Tongue out of the Mouth.

The third is the Ceratoglossus; it ari­ses broad and fleshy from the sides of the Os Hyoides, and is inserted into the root of the Tongue; it pulls the Tongue directly into the Mouth. The Fibres of this Muscles, which are nea­rest the Extremities of the Os Hyoides were only called the Ceratoglossus, and those which were nearest the basis of the Os Hyoides were called the Basio­glossus: But I see no reason to distin­guish them, being they lie in the same Plan, and their Fibres have the same Direction, Origination, and Insertion.

Of the Os Hyoides.The Tongue is not only moved by these Muscles, but also by a Bone called Os Hyoides. Now this Bone lies at the root of the Tongue; Its Figure is like the Greek letter v, it is composed ordinarily of three Bones, that in the middle makes its basis, it is shorter than the other two; it is Convex with­out, but Concave within; the other two are joined to its two ends, by two intervening Cartilages; they are much longer than the first; they have each a Cartilage at their Extremities, and they are called the Cornua, or Horns. [Page 181]The basis of this Bone is joined to the root of the Tongue, and its Horns are joined, by two small and round Ligaments, to the Processus Styloides of each side. This Bone is moved, and with it the Tongue by five Pair of Muscles.

Of its Mus­cles.The first is the Geniohyoidaeus; it ari­ses fleshy from the forepart of the lower Jaw internally, and is inserted into the basis of the Os Hyoides. It pulls the Os Hyoides and the Tongue upwards and forwards.

Its Antagonist is the Sternohyoidaeus; it arises from the inside of the Clavi­cula and upper Part of the Sternum, and ascending above the Sternothe­roidaeus, it's inserted into the basis of the Os Hyoides, which it pulls down­wards.

The third is the Mylohyoidaeus; it ariseth fleshy from the inside of the lower Jaw, under the Dentes Mola­res, and is implanted into the sides of the basis of the Os Hyoides. It draweth this Bone and Tongue ob­liquely upwards.

Its Antagonist is the Coracohyoidaeus; it is wrong named, for it arises not from the Processus Coracoides; but from the upper edge of the Scapula, near its Neck, and ascending oblique­ly, under the Mastoidaeus, it is in­serted [Page 182]into the Os Hyoides, which it pulls obliquely downwards. The Belly of this Muscle is a little tendinous in its middle, that the Vessels, which go to the Head, be not compressed when it acteth.

The fifth Pair is the Stylohyoidaeus; it arises from the Processus Styloides, and descending obliquely, is inserted into the Horns of the Os Hyoides, which it draws to one side, and a little up­wards.

The Belly of this Muscle is perfo­rated for the Passage of the Tendonin the middle of the Digastricus.

SECT. I. Of the Bones in general.

THo' after the Description of the three Cavities, it is usual to give the Myology; yet because it cannot be understood without a per­fect Knowledge of the Bones; there­fore we shall begin with them.

Of the Nou­rishment of the Bones.The Bones are made up of hard Fibres, tied to one another by small transverse Fibres, as those of the Mus­cles are. In a Foetus those Fibres are porous, soft, and easily discerned. It is probable that they are nourished by the Serous or Lymphatick Part of the Blood, which is brought to them by the Arteries, and carried back by the Veins. As their Pores fill, with a Substance of their own Nature, such as we suppose the Lympha to be, so they encrease, harden, and grow close to one another; but when their Pores are full of this Substance, then the Bones are grown to their outmost [Page 184]extent, hardness, and solidity, their Blood-Vessels being compressed on all sides by their bony Channels, bring no more Blood than what is sufficient to supply the places of their decaying Particles.

Of the Ʋse of the Marrow.All the Bones of the Body, which have any considerable thickness, have either a large Cavity, or they are Spongeous, and full of little Cells, in both the one and the other, there is an oleaginous Substance called Mar­row, contained in proper Vesicles or Membranes, which is separate from the Nourishment of the Bones, that they may harden; for as soon as the Marrow appears the Bones turn firm and solid, but is still continued in the Cavity and little Cells to supple the Fibres of the Bones, that they may be less apt to break.

All the Bones of the Body, except the Teeth, and those of the Ear, and where the Bones are articulate to one another, are covered with a thin, but close and strong Membrane called Peri­osteum; it has an exquisite sense, which gives me ground to think, that it is an Expansion of some of the tendi­nous Fibres of the Muscles. Its use is to sustain the Vessels, which enter the Substance of the Bones with their Nou­rishment.

Of the Cavi­ties and Pro­tuberances of the Bones.On the external Surface of the Bones there are several Cavities and Protube­rances. The Cavities are of two sorts, either narrow and shallow, or wide and deep. The first sort is called Glene; the second Cotyle. But in describing the Bones in particular, we shall also describe their Cavities. The Protu­berances are also of two sorts, viz. Apophisis and Epiphisis. The Apophisis is a Protuberance made by the Fibres of the Bone, produced above its Super­ficies, and Epiphisis is a Protuberance made by a small Bone set upon a big­ger Bone, which as we advance in Age, unite in one. Both the one and the other are ordinarily upon the Extre­mities of the Bones, and they are ei­ther for the Insertions of Muscles whose force they greatly augment, or for the Articulation of the Bones. All their difference is from their Figure. If it be a large and round Protuberance, it is called Caput, and the Part immedi­ately under it, Cervix; but if it be small and round, then it is called Con­dylus. If it be a sharp Protuberance, then it is called Corone, Styloides, Co­racoides, &c. according to its Figure.

Analysis of the Bones.In the Bones there is much volatile Salt and Spirit, which are very subtile and penetrating, some Sulphur which is very stinking, a little Phlegm, and much Earth.

SECT. II. Of the Cartilages and Ligaments in general.

A Cartilage is a smooth and solid Body, softer than a Bone, but harder than a Ligament. In it there are no Cavities nor Cells, for contain­ing of Marrow, nor is it covered with any Membrane to make it sensible, as the Bones are. The Cartilages have all a natural resort, by which, if they are forced from their Natural figure or situation, they return to it of them­selves, as soon as the force is taken away. They are chiefly in those places where a small and easie motion is re­quired, as in the Ears, Nose, Larynx, Trachea Arteria, and Sternum; and their Natural Elasticity serves instead of Antagonist Muscles. They cover al­so the ends of all the Bones, which are joined together for motion. First, Be­cause they are smoother than the Bones. Secondly, Because they are without sense. And Thirdly, Being softer than the Bones, the Attrition which is made by the motion of the Joint, is the more easily supplied.

A Ligament is a white and solid Bo­dy, softer than a Cartilage, but harder than a Membrane; they have no con­spicuous [Page 187]Cavities, neither have they any sense, lest they should always suffer upon the motion of the Joint. Their chief use is to fasten the Bones, which are articulated for motion toge­ther, lest they should be dislocated in any violent motion.

SECT. III. Of the Articulations of the Bones.

Of the joining of the Bones.THE Bones are articulated to one another two ways. The First, which is called Diarthrosis, is when the Articulation is with a manifest motion. The Second is when the Articulation is without motion, and it is called Synar­throsis.

There are three sorts of the Diar­throsis, viz. Enarthrosis, Arthrodia, and Ginglimus. The Enarthrosis is when a large Head is received into a deep Ca­vity, such as the Articulation of the Femur with the Ischium; and this sort of joining is called by Tradesmen, the Ball and Socket, which is used in large Mathematical Instruments, for the turn­ing of them to any side. Arthrodia is when a small Head is received into a shallow Sinus, as the Radius receives the Humerus. Tho' Authors have counted the Enarthrosis and the Ar­throdia as two distinct Articulations, [Page 188]yet we see no reason why they should be so; for as they say, Majus & Minus non variant speciem. The Ginglimus is when a Bone both receives and is re­ceived; and this sort of Articulation admits only of the motions of Flexion and Extension; and it is called by Tradesmen Charnall, and it is com­monly used in hinges. Of this Arti­culation there are three sorts. The first is when the end of a Bone has two Protuberances and one Cavity, and the end of the Bone which is articulated with it has two Cavities and one Protuberance, as the Hu­merus and the Ʋlna; or when a Bone at one Extremity receives ano­ther Bone, and at its other Ex­tremity it is received by the same Bone, as the Radius and Ʋlna. The second sort is when a Bone at one end receives another Bone, and at the other end it is received by a third Bone, as the Vertebrae do. The third is when a Bone has a Cavity which receives the long Process of another Bone, which Process turns in the Ca­vity, like the Axle-tree in a Wheel. As the second Vertebra of the Neck is articulated with the first; but this is no true Ginglimus.

The second sort of Articulation cal­led Synarthrosis is of two sorts, viz. [Page 189]Sutura and Gomphosis. The Sutura is when two Bones are mutually indent­ed in one another; the Teeth by which they are indented are of various Fi­gures, sometimes they are like the Teeth of a Saw; sometimes they are broad at their Extremities and narrow at their Basis; sometimes the sides of the Teeth are likewise indented, and sometimes there are little Bones be­tween the Teeth which are also in­dented; these are most frequently in the Sutura Lambdoidalis, and they serve as wedges to keep the Teeth firm. Besides these little Bones, there is or­dinarily a viscous Humour which glews the Indentations together, and which perfectly unites them in several old Persons.

This sort of Articulation is called by Joiners Duftelling, and is used in Drawers, Cabinets, and Boxes. All the Bones of the Cranium and upper Jaw, as also all the Epiphises of the Bones are joined by this sort of Arti­culation.

Gomphosis is when one Bone is fa­stened in another, as a Pin or Nail is in a piece of Wood, and the Teeth only are articulated this way in their Sockets. Authors add a third sort of Synarthrosis, which they call Harmonia, and by it, they say, the [Page 190]Bones of the upper Jaw are joined to one another, but these Bones are joined to one another by a true Su­ture.

There is still another way by which Bones are united, which Authors all Symphisis, which signifies a natural growing together of the Bones. And this is either with some intervening Substance or without it. The inter­vening Substance is either a Cartilage, Ligament, or Flesh. If it be a Car­tilage, then it is called Synchondrosis; this way the union of the Os Pubis and of the Bodies of the Vertebrae is performed, because this union remains always Cartilaginous. But the Syn­chondrosis of the Chin is nothing but the Fibres of the lower Jaw at the Chin not as yet ossified. If it be a Li­gament, then it is called Syneurosis; and there are none united this way but the Os Hyoides to the Processus Sty­loides, and the Extremity of the Ʋlna to the Bones of the Carpus. If it be Flesh, then it is called Syssarcosis; this way, they say, the Os Hyoides and the Scapula are united. But who sees not that the Muscles are not for their Ar­ticulation, but meerly for their mo­tion; and it seems to be more proper to say that the Bones are separated rather than articulated by the inter­vening [Page 191]Muscles. The other sort of Symphisis, which is when the Bones grow together, without any interve­ning Substance, is nothing but Part of the Bones not quite ossified.

The Extremities of all the Bones in the Body that are articulated to one another for motion, except those of the Ear, are covered with smooth and soft Cartilages, which greatly facilitate their motion: They are also surroun­ded with Membranes or Ligaments which commonly rise from the Con­junction of the Epiphises and the Bones: These Ligaments serve not only to strengthen the Joinings, and to keep the Heads of the Bones in their Cavi­ties; but it is probable that they have also Glands which separate that Muci­lage which is always found in the Joints, and which is as useful to them as Tallow is to Coach Wheels.

SECT. IV. Of the Bones of the Cranium.

THE Cranium or Skull is made up of several pieces, which being joined together, form a considerable Cavity, which contains the Brain as in a Box.

The bigness of the Cranium is pro­portionate to the bigness of the Brain. [Page 192]Its Figure is round, a little depressed on its sides. A round figure being the most capacious, was fittest to contain a great quantity of Brains. And the flatness of its sides, help to enlarge the Sight and Hearing.

Each Bone in the Cranium is made up of two Tables or Lamina, between which there is a thin and spongious Substance, made of some bony Fibres which come from each Lamina, called in Greek Diploe, in Latin Meditullium.

In it there are a great number of Veins and Arteries, which bring blood for the Nourishment of the Bones. The Tables are hard and solid, because in them the Fibres of the Bones are close to one another. The Diploe is soft, because the bony Fibres are at a greater distance from one another. By this contrivance, the Cranium is not only made lighter, but also less Subject to be broken.

The external Lamina is smooth, and covered with the Pericranium. The internal is likewise smooth; but on it there are several furrows made by the pulse of the Arteries of the Dura Ma­ter, whilst the Cranium was soft and yielding.

The Bones of the Cranium are joined to one another by four Sutures. Of the Sutura Coronalis. The first is called the Coronalis. It reaches [Page 193]transversly from one Temple to the other; Lambdoida­lis, Sagittalis and Squa­mosa. it joins the Os frontis, with the Ossa Parietalia. The second is called Lambdoidalis, because it resembles the Greek letter Λ Lambda; it joins the Os Occipitis to the Ossa Parietalia and Petrosa. The third is called Sagittalis; it begins at the top of the Lamb­doidalis, and runs straight to the mid­dle of the Coronalis; it joins the two Ossa Parietalia together. The fourth is called Sutura Squamosa, because the Parts of these Bones which are joined by this Suture slope, being mittered together.

This Suture joins the Semicircular circumference of the Ossa Temporum to the Os Sphaenoides Occipitis, and to the Ossa Parietalia. The first three Sutures were called Suturae Verae, and the last Sutura Falsa, because it was supposed to have no Indentations, which is false.

Of the Sutura Transversa­lis, Ethmoi­dalis, and Sphenoidalis.The Bones of the Cranium are not only joined to one another, but they are also joined to the Bones of the upper Jaw, by three other Sutures. The first is the Transversalis, it runs across the Face, it passes from the little Angle of the Eye down to the bottom of the Orbit, and up again by the great Angle of the Eye over the root of the Nose, and so to the little Angle [Page 194]of the Eye, in the other side. It separates the Os Frontis from the Bones of the upper Jaw. The second is the Eth­moidalis, it surrounds the Bone of that Name, and separates it from the Bones which are about it. The third is the Sutura Sphaenoidalis, it surrounds the Os Sphaenoides, separates it from the Os Occipitis, from the Ossa Petrosa, and from the Os Frontis.

The Cranium is made of several pie­ces, joined together by Sutures, that it might be the stronger, and less apt to break, that several Membranes and Ves­sels, which suspend the Dura Mater, and which go to the Pericranium, may pass thorow the Sutures, and that the Matter of transpiration may pass tho­row them.

Of the Bones of the Skull.Now the Bones of the Cranium are six proper, and two common to it and the upper Jaw. The six proper are, the Os Frontis, which makes the fore­part of the Skull; the Os Occipitis, which makes the hind-part; and the Ossa Parietalia and Temporum, which make the sides. The two common are, the Sphaenoides and the Os Eth­moides, which are Part of the basis of the Skull.

Os Frontis.The first of the Proper, is the Os Frontis or Coronale; it is almost round; it joins the Bones of the Sinciput, and [Page 195]temples by the Coronal Suture, and the Bones of the upper Jaw by the Sutura Transversalis, and the Os Sphae­noides by the Sutura Sphaenoidalis. It forms the upper Part of the Orbit, and it has four Apophises which are at the four Angles of the two Orbits. It has two holes above the Orbits thorow which pass a Vein, Artery, and some twigs of the first branch of the fifth Pair of Nerves. It has also one in each Orbit a little above the Os Planum, thorow which a twig of the Ophthal­mick branch of the fifth Pair passes to the Nose, it is the Orbiter Internus. It has two Sinus's above the Eye-brows, between its two Tables; they are lined with a thin Membrane, in which there are several Blood-Vessels and Glands, which separate a mucous Serosity, which falls into the Nostrils. The inside of this Bone has several Inequalities, made by the Vessels of the Dura Mater. It has two large dimples, made by the anterior Lobes of the Brain. Above the Crista Galli it has a small blind hole, into which the end of the Sinus Longitudinalis is inserted. From this hole it has a pretty large Spine which runs up along its middle; instead of this Spine, there is sometimes a Sinus, in which lies the Sinus Lon­gitudinalis, which ought to be obser­ved [Page 196]carefully by Surgeons in Wounds of this place. This Bone is thicker than the Sinciput Bones, but thinner than the Os Occipitis. In Children it is always divided in its middle by a true Suture.

Ossa Parie­talia.The second and third are the Bones of the Sinciput called Parietalia; they are the thinnest Bones of the Cranium, they are almost Square, somewhat long, they are joined to the Os Frontis, by the Sutura Coronalis, to one another in the Crown of the Head by the Sutura Sagittalis, to the Os Occipitis by the Lamboidalis, and to the Ossa Temporum by the Suturae Squamosae. They are smooth and equal on their outside, but on their inside they have several fur­rows, made by the Pulse of the Arte­ries of the Dura Mater. They have each a small hole near the Sutura Sa­gittalis, thorow which there pass some Veins which carry the Blood from the Teguments to the Sinus Longitudinalis.

Ossa Tempo­rum.The fifth and sixth are the Ossa Tem­porum, situated in the lower Part of the sides of the Cranium; their upper Part, which is thin, consisting only of one Table, is of a circular Figure, and is joined to the Ossa Parietalia by the Suturae Squamosae; their lower Part, which is thick, hard, and unequal, is joined to the Os Occipitis and to the [Page 197] Os Sphaenoides, this Part is called Os Pe­trosum; they have each three External Apophises or Processes, and one Inter­nal. The first of the External is the Processus Zygomaticus, which runs fore­wards and unites with the Process of the Os Mali, making that Bridge cal­led the Zygoma, under which lies the Tendon of the Crotaphite Muscle. The second is the Mammillaris, or Mastoi­daeus; it is short and thick, situated behind the Meatus Auditorius. The third is the Processus Styliformis, which is long and small; to it the Horns of the Os Hyoides are tied. The Internal Process is pretty long and big in the basis of the Skull, it contains all the Cavities and little Bones of the Ear, which have been already described. The holes in the Temporal Bones are two Internal and four External. The first of the Internal, is the hole thorow which the Auditory Nerve passes, the second is common to it and the Os Oc­cipitis; the eighth Pair of Nerves, and the Lateral Sinus's pass thorow it. The first of the External holes is the Mea­tus Auditorius Externus; the second is opened behind the Palate; it is the end of that Passage which comes from the Barrel of the Ear to the Mouth. The third is the Orifice of the Conduit by which the Carotidale Arteries enter the [Page 198] Cranium, and the fourth is behind the Processus Mastoidaeus; by it passes a Vein which carries the Blood from the Ex­ternal Teguments to the Lateral Sinus's. Sometimes this hole is wanting; there is another which is between the Pro­cessus Mastoidaeus and the Styliformis, thorow which the Portio Dura of the Auditory Nerve passes. They have each a Sinus lined with a Cartilage under the Meatus Auditorius, which receives the condyle of the lower Jaw.

Os Occipitis.The sixth Bone of the Cranium is the Os Occipitis; it lies in the hind part of the Head; it is almost like a Lozenge with its lower Angle turned inwards, it joins the Ossa Parietalia and Petrosa by the Sutura Lambdoidalis, and the Os Sphaenoides by the Sphaenoidalis. It is thicker than any of the other Bones of the Cranium, yet it is very thin where the Splenius, Complexus and Tra­pezius are inserted. Externally it is rough, internally it has two Sinus's, in which lie the two Protuberances of the Cerebellum, and two large furrows in which lie the Sinus Laterales. It has seven holes; the first two are com­mon to it and the Ossa Petrosa, the La­teral Sinus's, and the Par Vagum, pass thorow them. The third is the great hole thorow which the Medulla Spi­nalis passes. The fourth and fifth are [Page 199]the holes, thorow which the ninth Pair of Nerves passes. The sixth and seventh are two holes, thorow which there pass two Veins, which bring the Blood from the External Teguments to the Sinus Laterales; sometimes there is but one, and sometimes none of these two; there are sometimes two more thorow which the Vertebral Veins pass. This Bone has also two Apophises, one on each side of the great hole; they are lined with a Cartilage, and articu­lated with the first Vertebra of the Neck. It has also a small Protube­rance in its middle, from which there goes a small Ligament, which is inser­ted into the first Vertebra of the Neck. It is longer in Beasts than in Men.

Os Sphae­noides.The first of the Bones common to the Skull and upper Jaw is the Sphae­noides. It is a Bone of a very irregular figure. It is situated in the middle of the basis of the Skull. It is joined to all the Bones of the Cranium by the Sutura Sphaenoidalis, except in the mid­dle of its sides, where it is continued to the Ossa Petrosa as they were one Bone. On its outside it has five Apo­phises. The first two are broad and thin like a Bat's Wings, they are cal­led Pterigoides; they have each a pret­ty long Sinus, from which the Muscles called Pterigoidaei arise, and at their [Page 200]lower end they have each a small hook like a Process, upon which the Peri­staphilinus Externus turns its Tendon. The third and fourth make the Inter­nal and lower Part of the Orbit; and the fifth is a little Apophise like the Crista Galli in its forepart, which is received in a Cavity at the further end of the Vomer. There is also a little small Protuberance in the middle of this Bone, from which the Muscles of the Ʋvula arise. On its inside it has four Processes called Clinoides; they form a Cavity in the middle of this Bone called Cella Turcica, in which lies the Glandula Pituitaria. Betwixt the two Tables of this Bone, under the Cella Turcica there is a Sinus, divided in two in its middle, which opens by two holes into the Cavity of the No­strils. In the Os Sphaenoides there are twelve holes; by the first and second pass the Optick Nerves; by the third and fourth, which are called Foramina Lacera, pass the third Pair, fourth Pair, first branch of the fifth Pair, and the sixth Pair; by the fifth and sixth pass the second branch of the fifth Pair; by the seventh and eigth pass the third branch of the same Pair; by the ninth and tenth enter the Arteries of the Du­ra Mater; and by the eleventh and twelfth enter the Internal Carotidales, [Page 201]and the Intercostal Nerve goes out. The Canal by which the Carotidales enter are oblique, the beginning of them is made in the Ossa Petrosa, and they open within the Skull in the Sphaenoides.

Os Ethmoi­des.The second and last of the common Bones is the Os Ethmoides, situated in the middle of the basis of the Os Frontis, joined to that Bone and to the Os Sphae­noides by the Sutura Ethmoidalis. In its middle it has a small Process called Crista Galli, to which the fore-end of the Falx is tied. This Bone is perfo­rated by a number of small holes, tho­row which the Fibres of the Olfactory Nerve pass; therefore it is also called Os Cribriforme. From its under side there goes a thin Bone, which divides the Cavity of the Nostrils in two; the lower edge of this Bone is Grouved with the Vomer. On each side of this Partition it has several thin spongious Laminae, called Ossa Spongiosa, they are full of little Cells, where they are joined to the Ethmoides. There are two Laminae which neither adhere to the Os Ethmoides, nor to the other Laminae, but only by the Membrane which covers them all. These two were first observed by Mons. du Ver­ney. The two External Laminae of the Ossa Spongiosa, make Part of the [Page 202]Orbit at the great Canthus, and they are called Ossa Plana, because they are smooth and even.

SECT. V. Of the Bones of the Ʋpper Jaw.

THE Bones of the Upper Jaw are two common to it and the Skull, which have been already described, and eleven Proper, that is five in each side, and one in the middle; they are joined to the Bones of the Skull by the three common Sutures, and joined to one another by a fine but true Suture.

Os Mali.The First of the Proper Bones is the Os Mali or Zygoma; it is of a trian­gular Figure. It's upper side makes the lower and external Part of the circumference of the Orbit, where it joins the Os Sphaenoides. Its Internal side joins the Os Maxillare. Its Ex­ternal has a long Process, which join­ing that of the Ossa Temporum forms the Processus Zygomaticus; it joins the Os Frontis at the little Angle of the Eye. It is Concave within, and it sticks out a little forwards making the highest Part of the Cheek.

Os Maxillare.The Second is the Os Maximum or Maxillare, because in it all the Teeth of the Upper Jaw are set. It is of a very irregular Figure. On its outside it [Page 203]joins the Os Mali. Its upper side makes the lower and Internal circumference of the Orbit. At its great Canthus it joins the Os Ʋnguis and Frontis. The lower side of the Os Nasi is joined to it. Under the upper Lip it joins with its fellow of the other side, and both joined together make the fore and greatest Part of the Roof of the Mouth. It is very thin, and between its two Laminae it has a large Cavity which opens by a small hole into the Nostrils. In its lower end it has sixteen Sinus's or Sockets, in which the Teeth are set. It has a small hole called Orbiter Ex­ternus, in that Part of it which makes Part of the Orbit; and a little under this in its middle, it has another, thorow which the Nerves of the fifth Pair which come from the Teeth pass. Behind the Dentes Incisivi, where it joins with its fellow it has another which comes from the Nostrils.

Os Unguis.The Third is the Os Ʋnguis, it is a little thin Bone which lies in the great Angle of the Orbit, it has a hole in which the Lachrymal Sack lies. I see no reason why this Bone should be counted a Bone of the Upper Jaw, be­ing it lies entirely in the great Angle of the Orbit; there is more reason to count it a Lamina of the Os Spongiosum as the Os Planum.

Os Nasi.The Fourth is the Os Nasi; this is a thin but solid Bone, which makes the upper Part of the Nose; its upper end is joined to the Os Frontis by the Su­tura Transversalis: One of its sides joins its fellow, and its lower is joined to the Os Maxillare. Upon its lower end the Cartilages of the Nostrils are fastened. Externally it is smooth, but Internally it is rough.

Os Palati.The Fifth Bone of the Upper Jaw is the Os Palati; it is a small Bone al­most square, it makes the Posterior Part of the Roof of the Mouth. It is joined to that Part of the Os Maxillare which makes the forepart of the Pa­late. It is also joined to its fellow and to the Processus Pterigoidaeus. It has a small hole thorow which a branch of the fifth goes to the Membrane of the Palate.

The Eleventh and Last is called the Vomer, Vomer. it is situated in the middle of the lower Part of the Nose. It has a cleft in its upper side, in which cleft it receives the lower edge of the Sep­tum Nasi. In its further end it receives a small Apophise of the Os Sphaenoides, and its under side the Os Palati.

By what has been said you see that the Bones of the Skull and Upper Jaw compose the Orbit of the Eye. The upper Part of it is made of the Os [Page 205]Frontis; the Os Ʋnguis, and Os Planum make the inner and lower Part of the great Angle; and the Os Sphaenoides the inner and lower of the little Angle. The Os Maxillare makes the inner and lower Part of the Circumference, and the Os Mali the outer and lower Part.

Let us now briefly Recapitulate all the holes in the Head. They are either External or Internal. The External holes are,

• 1. The two in the Coronal Bone above the Orbit thorow which a Vein, Artery and a Nerve from the Ophthalmick branch of the fifth Pair passes for the brow and frontal Mus­cles.
• 2. The Orbiter Internus in the same Bone within the Orbit a little above the Os Planum, for another branch of the fifth Pair of Nerves which goes to the Nose.
• 3. Is be­tween the Os Ʋnguis and the Os Maxil­lare, in the great Canthus, thorow which the Ductus Lachrymalis passes to the Nose.
• 4. Orbiter Externus in the Os Maxillare below the Orbit, thorow which the Nerves and Vessels which come from the Teeth pass to the Cheek.
• 5. One single hole in the same Bone behind the fore Teeth which comes from the Nose.
• 6. Two in the Ossa Palati thorow which a branch of the fifth Pair of Nerves passes to the [Page 206]Palate, Ʋvula and Gums.
• 7. In the Tem­poral Bone between the. Processus Ma­stoidaeus and Styliformis, thorow which the Portio Dura of the Auditory Nerve passes.
• 8. The Ductus Auditorius Ex­ternus.
• 9. The Ductus Auditorius In­ternus.
• 10. The Conduit for the Ca­rotidale Artery.
• 11. In the same Bond thorow which a Vein passes from the External. Teguments to the Lateral Sinus's; this is behind the Processus Ma­stoidaeus.
• 12. In the Occipital Bone behind its Apophises thorow which the Vertebral Veins pass.
• 13. In the same Bone for a branch of the External Ju­gular.
• 14. One single large hole for the Medulla Spinalis.

The Internal holes are,

• 1. The blind hole above the Crista Galli.
• 2. The holes in the Os Ethmoides.
• 3. In the Os Sphaenoides for the Optick Nerves.
• 4. The Foramen Lacerum, thorow which the 3, 4, first branch of the fifth and sixth Pair of Nerves pass.
• 5. For the second branch of the fifth Pair of Nerves.
• 6. For the third branch of the same Nerve.
• 7. The Foramen Arteriae durae Matris.
• 8. The Canal thorow which the Carotidale enters, and the Intercostal passes out, but this we counted amongst the External holes.
• 9. In the Process of the Os Temporum thorow the Auditory Nerve [Page 207]passes,
• 10. Between the Temporal and Occipital Bones, it is divided in two by the Dura Mater, thorow the one Part passes the eighth Pair of Nerves and the Nervus Accessorius; thorow the other the Lateral Sinus's open in­to the Internal Jugulars.
• 11. One in each side of the large hole in the Occi­put, thorow which the ninth Pair of Nerves go out.

SECT. VI. Of the Lower Jaw.

THE Lower Jaw is made of one Bone whose Fibres at the Chin, in Children do not ossifie till they are about two Years old. It is composed of two Tables, which are pretty hard and smooth; but betwixt these two Laminae it is porous and full of little Cavities; its figure resembles the letter v; at each Extremity it has two Pro­cesses, the uppermost is called Corone; it is thin and broad at its beginning, but it ends in a sharp Point, which passing under the Processus Zygomaticus, has the Tendon of the Crotaphite mus­cle inserted into it. The other which is shorter and lower has a round Head, lined with a Cartilage, which is arti­culated into the Sinus of the Os Petro­sum; but betwixt the Cartilage which [Page 208]lines the Sinus, and that which covers the Head of this Process there is a third, which adheres to the Ligamentum An­nulare which surrounds this Articula­tion. The Motion of the Jaw side­ways, which is absolutely necessary in chewing, is much facilitated by this loose intervening Cartilage. The lower edge of this Jaw is called its basis, each end of which is called the Angle of the Lower Jaw.

The Lower Jaw has four holes, two on its inside near its Processes, and two on its outside near its middle. By the Internal holes enter a branch of the fifth Pair of Nerves, a Vein from the Jugulars, and an Artery from the Ca­rotidales, which give twigs to the roots of the Teeth. By the External holes these same Vessels come out, and are distributed upon the Chin. It has also Sixteen Sinus's into which the Teeth are set.

SECT. VII. Of the Teeth.

Of the Sub­stance of the Teeth.THE Teeth are the hardest and smoothest Bones of the Body; they are formed in the Cavities of the Jaws, which are lined with a thin Membrane, upon which there are seve­ral Vessels, thorow which there passes [Page 209]a thick, viscous, transparent Humour, which, as it encreases, hardens in the form of Teeth, which about the seventh or eighth Month after Birth, begin to pierce the edge of the Jaw, tear the Periosteum and Gums, which being very sensible create a violent Pain and other Symptoms incident to Children in the time of teething.

The Teeth begin not to appear all at one time; First the Dentes Incisivi of the Upper and then those of the Lower Jaw appear, because they are the thin­nest and sharpest. After them come out the Canini, because they are shar­per than the Molares, but thicker than the Incisivi; and last of all the Molares, because they are the thickest and blunt­est. Of this viscous transparent Li­quor which is the Substance of the Teeth, there are two Lays, the one below the other, divided by the same Membrane which covers all the Cavity of the Jaw; the uppermost Lay forms the Teeth which come out first, but about the Seventh year of Age, they are thrust out by the Teeth made of the undermost Lay, which then begin to sprout; and if these Teeth be lost, they never grow again; but if some have been observed to cast their Teeth twice, they have had three Lays of this viscous Humour. About the one and [Page 210]twentieth Year, the two last of the Molares spring up, and they are called Dentes Sapientiae.

Of the Dentes Incisivi.The Teeth, which are sometimes fourteen, sometimes fifteen, and some­times sixteen in each Jaw, are of three sorts; the Dentes Incisivi, Canini, and Molares. The Incisivi are the four foremost Teeth in each Jaw, they are pretty broad, sharp at their ends, a little convex outwards, and hollow inwards; they have each a pretty long root, a little crooked, and divided in two, by which means they have the greater force in cutting off the Ali­ments, which is their proper use. The Canini are two in each Jaw, Canini. one on each side of the Incisivi; they are pret­ty thick and round, and they end in a sharp Point; they have each one root which is longer than the roots of the Incisivi; their proper use is to pierce the Aliments. Molares. The Molares ordinarily are ten in each Jaw; they are the thickest and biggest of the Teeth; their Extremities are broad and uneven; they have sometimes two, sometimes three, and sometimes four roots which sepa­rate a little from one another, that they having a broad basis they may find the greater resistance from the Jaw when they press upon one ano­ther in chewing of the Aliments; and [Page 211]the pressure has the less force, being the roots are a little crooked outwards, and not in a straight line under the pressure. The last of the Molares are the biggest and hardest, because we ordinarily thrust the hardest Bodies furthest into our Mouth; they are nighest the Articulation, because their use, which is to grind the Aliments small, requires the greatest strength. The Roots of the Teeth of the Upper Jaw are all somewhat larger than those of the Under Jaw, because the Upper Jaw is not so strong to resist the pres­sure of the Teeth as the Lower is.

SECT. VIII. Of the Spine and Vertebrae.

The Number of the Vertebrae.BY the Spine we understand that chain of Bones which reaches from the first Vertebra of the Neck to the Os Coccigis; they are thirty in num­ber, seven Vertebrae of the Neck, twelve of the Back, five of the Loins, and six of the Os Sacrum; they lie not in a straight line, for those of the Neck bend inwards, those of the Back out­wards for enlarging the Cavity of the Thorax; those of the Loins bend in­wards again, and those of the Os Sa­crum outwards, to enlarge the Cavity of the Basin.

The Parts of the Vertebrae.In each Vertebra we distinguish two Parts, the Body of the Vertebra and its Processes; the Body is foster and more spongious than the Processes which are harder and more solid. The forepart of the Body is round and Convex, the hindpart somewhat Concave; its up­per and lower sides are plain, each co­vered with a Cartilage, which is pretty thick forwards, but thin backwards, by which means we bend our Body forwards; for the Cartilages yield to the pressure of the Bodies of the Ver­tebrae, which in that motion come clo­ser to one another. This could not be effected, if the harder Bodies of the Vertebrae were close to one another. Each Vertebra has three sorts of Pro­cesses towards its hinder part; two transverse or lateral, one on each side; they are nearer the Body of the Vertebrae than the rest. In each of them there is a Tendon of the Vertebral Muscles in­serted. Four oblique Processes, two on the upper Part and two on the lower, by these the Vertebrae are articulated to one another; and one acute on the hindmost Part of the Vertebra.

These Processes with the hinder or concave Part of the Body of the Verte­bra, form a large hole for the descent of the Spinal Marrow. Besides this hole, there are two small holes on their upper [Page 213]sides, and two on their under sides for the Passage of the Spinal Nerves; these holes as made by two Sinus's on the under side of the Superior Vertebra, and two Sinus's on the upper side of the In­ferior Vertebra, which answering the former Sinus form these holes.

Of the Arti­culation of the Vertebrae,The Vertebrae are articulated to one another by a Ginglimus, for the two descending oblique Processes of each Superior Vertebra of the Neck and Back have a little dimple in their Extremi­ties, wherein they receive the Extre­mities of the two ascending oblique Processes of the Inferior Vertebra; so that the two ascending Processes of each Vertebra of the Neck and Back are received, and the two descending do receive, except the first of the Neck and last of the Back; but the ascend­ing Processes of each Vertebra of the Loins receive, and the two descending are received contrary to those of the Neck and Back.

The Vertebrae are all tied together by a hard Membrane, made of strong and large Fibres, it covers the Body of all the Vertebrae forwards, reaching from the first of the Neck to the Os Sacrum; there is another Membrane which lines the Canal, made by the large hole of each Vertebra, which also ties them all together. Besides the [Page 214]Bodies of each Vertebra are tied to one another by the intervening Cartilages and the Tendons of the Muscles, which are inserted in their Processes, tie them together behind.

Of the Verte­brae of the Neck.The seven Vertebrae of the Neck differ from the rest in this, that they are smaller and harder. Secondly, That their transverse Processes are perforated for the Passage of the vertebral Vessels. Thirdly, That their acute Processes are forked and straight; but besides this, the first and second have some­thing peculiar to themselves.

The First, Atlas. which is called Atlas, is tied to the Head, and moves with it upon the Second semi-circularly; its ascending oblique Processes receive the Tubercles of the Occiput, upon which Articulation the Head is only bended and extended, and its descending Pro­cesses receive the ascending Processes of the second Vertebra. It has no acute Process, that it might not hurt the action of the Musculi Recti; but a small Tubercle to which the small Li­gament of the Head is inserted. In the hindpart of its great hole, it has a pretty large Sinus, in which lies the Teeth-like Process of the second Ver­tebra, being fastened by a Ligament that rises from each side of the Sinus, that it compresses not the Medulla Spi­nalis. [Page 215]It has two small Sinus's in its upper Part, in which the tenth Pair of Nerves and the Vertebral Arteries lie.

The Second is called Epistrophoeus or Vertebra Dentata, Epistrophaeus in the middle between its two oblique ascending Processes; it has a long and round. Process like a Tooth which is received into the fore­said Sinus, upon it the Head with the first Vertebra turns half round as upon an Axis. The Extremity of this Pro­cess is knit to the Occiput by a small but strong Ligament. A Luxation of this Tooth is mortal, because it com­presses the Medulla Spinalis.

The Third Vertebra is called Axis; Axis. and the four following have no name, nor any peculiar difference.

Of the Verte­brae of the Back. The Twelve Vertebrae of the Back differ from the rest in this, that they are larger than those of the Neck, and smaller than those of the Loins; their acute Processes slope downwards upon one another: They have in each side of their Bodies a small dimple wherein they receive the round Extremities of the Ribs, and another in their trans­verse Processes, which receives the lit­tle Tubercle near that Extremity of the Ribs. The Articulation of the twelfth with the first of the Loins is by Arthrodia, for both its ascend­ing [Page 216]and descending oblique Processes are received.

Of the Verte­brae of the Loins. The Five Vertebrae of the Loins differ from the rest in this, that they are the broadest and the last of them is the largest of all the Vertebrae. Their acute Processes are broader, shorter and wi­der from one another, their Transverse longer, to support the Bowels, and the Muscles of the Back; they are not per­forated as those of the Neck, nor have they a dimple or Sinus as those of the Back. The Cartilages which are be­twixt their Bodies are thicker than any of the rest.

Of the Os Sa­orum. The Six Vertebrae of the Os Sacrum grow so close together in Adults as that they make but one large and solid Bone of the figure of an Isosceles Tri­angle, whose basis is tied to the last Vertebra of the Loins, and the upper Part of its sides to the Os Ilia, and its Point to the Os Coccigis. It is Concave and smooth on its foreside, but Con­vex and unequal on its backside. It hath five holes on each side, but the Nerves pass only thorow the five on its foreside. Its acute Processes or Spines are shorter and less than those of the Loins, and the lower is always shorter than the upper.

Os Coccigis.The Os Coccigis is joined the Ex­tremity of the Os Sacrum; it is com­posed [Page 217]of three or four Bones, of which the lower is still less than the upper, till the last ends in a small Cartilage; it resembles a little tail turned inwards; its use is to sustain the straight Gut; it yields to the pressure of the Foetus in Women in Travail, and Midwives use to thrust it backwards, but some­times rudely and violently, which is the occasion of great Pain, and of se­veral bad Effects.

From what has been said, it is easie to understand how the Motion of the Back is performed; tho' each particu­lar Vertebra has but a very small Mo­tion, yet the Motion of all is very con­siderable. We have said that the Head movese only backwards and forwards upon the first Vertebra, and Semi-cir­cularly upon the second. The small Protuberance which we have remarked in the Bone of the hind Head falling upon another in the first Vertebra stops the Motion of the Head backwards, that it compress not the Spinal Mar­row, and when the Chin touches the Sternum, it can move no further for­wards. The Oblique or Semicircular Motions are limited by the Ligament which ties the Process of the Second Vertebra to the Head, and by those which tie the first to the second Ver­tebra. The Motion of the other Ver­tebrae [Page 218]of the Neck is not so manifest, yet it is greater than that of the Ver­tebrae of the Back, because their acute Processes are short and straight, and the Cartilages which are between their Bodies thicker. The twelve Vertebrae of the Back have the least Motion of any, because their Cartilages are thin, their acute Processes are long and very near to one another; and they are fixed to the Ribs, which neither move forwards nor backwards. But the greatest Motion of the Back is per­formed by the Vertebrae of the Loins, because their Cartilages are thicker, and their acute Processes are at a grea­ter distance from one another, for the thicker the Cartilages are, the more we may bend our Body forwards; and the greater distance there is betwixt the acute Processes the more we may bend our selves backward.

This is the Structure and Motion of the Vertebrae when they are in their natural Position: but we find them also in several persons several ways di­storted. If the Vertebrae of the Back stick out, such as have this Deformity are said to be bunch-backed, and in such the Cartilages which are between the vertebrae, are very thin and hard forwards, but considerably thick back­wards, where the oblique Processes of [Page 219]the Superior and Inferior Vertebrae are at a considerable distance from one another, which distance fills up with a viscous Substance. This inequality of the thickness of the Cartilages hap­pens either by a relaxation, or weak­ness of the Ligaments and Muscles which are fastened to the backside of the Vertebrae, in which case their Anta­gonists finding no opposition, remain in a continual Contraction, and conse­quently there can be no Motion in these Vertebrae. If this Deformity has been from the Womb, then the Bones being at that time soft and tender, the Bodies of the Vertebrae partake of the same inequality as the Cartilages. If the bunch be towards one Shoulder for example towards the right, then the Cartilages on that side are very thick, but thin and dry on the other side; on the left side the oblique Apo­phises come close together, but on the right there is a considerable distance betwixt them; and the Ligaments and Muscles are greatly extended on the right side, but those on the left are as much contracted. If the Vertebrae are distorted inwards, all things have a different Face: The Cartilages and sometimes the Vertebrae are very thick forwards, but mighty thin and hard backwards; the acute and oblique Pro­cesses [Page 220]are very close to one another, and the Ligaments upon the Bodies of the Vertebrae are greatly relaxed, but the Muscles and Ligaments which tie the Processes together are very much contracted. These Distortions seldom happen in the Vertebrae of the Loins, but such as are so miserable have little or no Motion of their Back.

SECT. IX. Of the Ossa Innominata.

THE Ossa Innominata are two large Bones situated on the sides of the Os Sacrum; in a Foetus they may be each separated into three pieces, which in Adults unite and make but one Bone, in which they distinguish three Parts. The first and Superior Part is called Os Ilium; the Intestine Ileum lieth between it, and its fellow. It is very large, almost of a Semicircular Figure, a little Convex and uneven on its Ex­ternal side, which is called its Dorsum, and Concave and smooth on its Inter­nal side, which is called its Costa. Its circumference or edge is called its Spine. It is joined to the sides of the three Su­perior Vertebrae of the Os Sacrum by a true Suture; it is larger in Women than in Men.

Os Publis.The second is the Os Pubis, which is the inferior and forepart of the Os In­nominatùm, 'tis united to its fellow of the other side by an intervening Cartilage, by which means it makes the forepart of the Pelvis or Bason, of which the Os Sacrum is the back Part, and the Ilia the sides.

Os Ischium.The third is the Inferior and Poste­rior Part called Ischium or Coxendix, it has a large Cavity called Acetabulum Coxendicis, which receives the head of the Thigh Bone; the circumference of this Cavity is tipt with a Cartilage called its Supercilium, where it joins the Os Pubis; it has a large hole called Fo­ramen Ischij & Pubis, about the cir­cumference of which the Muscles called Obturator Internus and Externus arise. And at its lowest end it has a large Protuberance upon which we sit, and from whence the benders of the Leg arise. And a little above this, upon its hinder Part it has another small acute Process, betwixt which and the for­mer Protuberance lies the Sinus of the Ischium, thorow which the Tendon of the Obturator Internus passes.

SECT. X. Of the Ribs.

THere are 24 Ribs, Costae.twelve on each side of the twelve Vertebrae of the Back; they are crooked and like to the Segments of circles; they grow flat and broad as they approach the Sternum, but the further they are from it, and the nearer they are to the Ver­tebrae they are the rounder and thicker, at which end they have a round head, which, being covered with a Cartilage, is received into the Sinus in the Bodies of the Vertebrae, and at the Neck of each Head (except the two last Ribs) there is a small Tubercle, which is also received into the Sinus of the transverse Processes of these same Ver­tebrae.

The Internal Superficies of the Ribs is smoother than the External; they have each a small Canal or Sinus, which runs along their under sides, in which lies a Nerve, Vein, and Artery. The Substance of the Ribs is partly bony, partly cartilaginous, which facilitates their Motion in Respiration. At their cartilaginous end they are tied to the Sternum, where they are harder in Wo­men than in Men, that they may the better bear the weight of their Dugs.

The Ribs are of two sorts, the seven upper are called Costae Verae, because their Cartilaginous ends are received into the Sinus's of the Sternum. The five lower are called Falsae, because they are shorter and softer, of which only the first is joined to the Extre­mity of the Sternum, the Cartilaginous Extremities of the rest are tied to one another, thereby leaving greater space for the dilatation of the Stomach and Intrals. The last of these false Ribs is shorter than all the rest; it is not tied to them, but sometimes to the Midriff, and sometimes to the Muscu­lus Obliquus Descendens.

The use of the Ribs is to contain and defend the Heart and Lungs, to sustain the Muscles which move them in Respiration.

SECT. XI. Of the Breast Bone.

THE Sternum or Breast Bone is situ­ated in the middle of the Breast; Sternum▪ it is composed of seven or eight Bones in Infants, which at first are Cartila­ginous, but which harden and unite into three Bones after they are seven years old; the Substance of these Bones is not solid but somewhat spongious.

The first and uppermost Bone is the biggest and largest; it is uneven and rough on its outside, but smoother on its inside, where it has a shallow furrow which gives way for the de­scent of the Wind Pipe. It has a Sinus lined with a Cartilage on each side of its upper end, wherein it receives the Heads of the Claviculae.

The second is longer and narrower than the first, and on its sides there are several Sinus's, in which the Cartila­ginous ends of the Ribs are received.

The third is shorter but broader than the second, it receives into the Lateral Sinus's the Extremities of the last true Ribs; it terminates into a Cartilage which hardens sometimes in­to a Bone, called Cartilago Xiphoides, or Ensiformis, because it is broad at its upper end, where it joins the third Bone, and grows narrower to its Extremity, where it is sometimes forked, and sometimes it bends in­wards, compresses the upper Orifice of the Stomach, and causes a great Pain and Vomiting.

The use of the Sternum is to defend the Heart, and to receive the Extre­mities of the true Ribs.

SECT. XII. Of the Claviculae and Scapulae.

THE Claviculae or Channel Bones are two in number, Claviculae. situated at the basis of the Neck, above the Breast, one on each side, they are pretty long and small; at one end they are joined to the Production of the Scapula, cal­led Acromion, by the Articulation called Synchondrosis, at the other end, to the upper end of the Sternum, by the Ar­ticulation called Arthrodia; they are crooked like an Italian S, for the Pas­sage of the Vessels which pass under them, and to facilitate the Motion of the Arms.

Their Substance is Spongious, with a Cavity in their middle, therefore they are the more easily broken, and the sooner united when broken; their use is to uphold the Arms, to keep them at a little distance from the Sternum; therefore Beasts which make not use of their Hoofs as Hands, have no Claviculae, whilst Apes, Rats, and several others, which do use their fore Legs as we do our Hands, have them.

The Scapulae, [...], or Shoulder-blades, Scapulae are two large and broad Bones, like the Triangle called Scalenum; they [Page 226]are situated on each side of the upper and back part of the Thorax; their Substance is thin, but solid and firm; their outside is somewhat Convex and their inside Concave; their upper edge is called Costa Superior, and their lower Costa Inferior; their broad end is called their Basis, which, with the two edges, make the upper and lower Angles. They have each three Processes, of which the first runs all along the mid­dle of their outside, and 'tis called their Spine. That end of the Spine which receives the Extremity of the Clavi­cula is called Acromion. The second Process is a little lower than the Acro­mion; 'tis short and sharp like a Crow's Bill, therefore called Coracoides; these two Processes are tied to one another by a strong Ligament which serves to keep the Head of the Humerus, in the Cavity of the third Process, which is called Cervix. This Process is the Ex­tremity of the Scapula, which is oppo­site to its basis. It has a pretty large and round Sinus, tipt about its brim with a Cartilage, which makes it the deeper, it receives the head of the Hu­merus.

The use of the Scapula is to receive the Extremities of the Clavicula, and Hu­merus, for the easier motion of the Arm, and to give a rise to the Muscles which move the Arm.

SECT. XIII. Of the Bones of the Arm and Hand.

The Humerus.THE first Bone of the Arm is the Humerus, or Shoulder Bone; 'tis long and round, its Substance or Fi­bres are pretty solid and compact; it has a pretty wide and long Cavity in its middle, in which is contained its Marrow. At its upper end it has a round Head covered with a Cartilage, which is received into the Cavity of the Neck of the Scapula; but because this Head is much larger than the Ca­vity, therefore it is surrounded with a strong Ligament, which rises from the edge of the Cavity of the Scapula. At its lower end it has two Protuberances; the one External, which receives the Extremity of the Radius; the other Internal, which is received into the Se­micircular Sinus of the Ʋlna. On the foreside of this Protuberance there is a small Sinus which receives the fore Pro­cess of the Ʋlna; and on the backside there is another large Sinus which re­ceives the Olecranium. There is ano­ther small Protuberance on the side of this, from which the Muscles that lie on the inside of the Arm arise.

The Ʋlna or Cubitus, Ulna. is a long and solid Bone with a Cavity in its middle. [Page 228]It lies on the inside of the fore Arm, reaching from the Elbow to the Wrist; it is big at its upper end, and grows smaller to its lower end. At its upper it has two Processes which are received into the fore and hind Sinus's of the Extremity of the Humerus; the fore­most Process is small and short, the hindmost called Olecranium is bigger and longer; it stays the fore Arm when it comes to a straight line with the Arm. Betwixt these Processes it has a Semicircular Sinus, which receives the inner Protuberance of the lower end of the Humerus, upon which we bend and extend our fore Arm.

The inside of this upper end has a small Sinus which receives the Circum­ference of the round Head of the Ra­dius. Its lower Extremity which is round and small is received into a Si­nus in the lower end of the Radius, and upon this Extremity it has a short and small Process, from which the Liga­ments which tie it to the Bones of the Wrist arise; this Process serves to keep the Bones of the Wrist in their place.

The Radius is another Bone of the fore Arm, Radius. which accompanies the Ʋlna from the Elbow to the Wrist; in its upper end it has a small Cavity which receives the outer Protuberance of the Humerus. The Circumference of this [Page 229]Cavity rouls into the small Sinus in the upper end of the Ʋlna. Near its lower end, which is bigger than its upper, it has a little Sinus which receives the end of the Ʋlna, and in its Extremity it has two Sinus's which receive the Bones of the Wrist. Altho' the Ʋlna and the Radius accompany one ano­ther, yet they touch not but at their Extremities. They bend from one ano­ther in their middle, but they are tied together by a strong and broad mem­branous Ligament.

The Ʋlna is articulated to the Hume­rus by a Ginglimus, which only admits of the motion of Flexion and Exten­sion, to the end that when we lift any great weight, the Ʋlna may not turn to a side, and so avoid the resistance of the weight. But because if the Hand were only confined to this Motion, we could have but little use of it; there­fore the Wrist is joined to the Radius which performs the Motion of Prona­tion, and Supination, by which means the hands partake of the Motion of both Bones.

The Bones of the Carpus.The Carpus or Wrist is made up of eight little Bones of a different Figure and bigness; they are placed in two ranks, four in each rank. The first rank is articulated with the Radius. The second with the Bones of the Me­tacarpus. [Page 230]The last little Bone of the first rank lies not at the side of the third, which answers to the Bone of the Metacarpus of the little Finger, as all the rest do by one another, but it lies upon it; They are strongly tied together by the Ligaments which come from the Radius, and by the annulary Ligaments, thorow which the Tendons which move the Fingers pass. Altho' this Ligament be thought but one, yet it gives a particular case to every Ten­don which passes thorow it.

The Bones of the Metacar­pus.The Metacarpus is made up of four Bones which answer the four Fingers; that which sustains the Fore-finger is the biggest and longest; they are round and long, a little Convex and round towards the back of the Hand, and Concave and plain towards the Palm. They are hollow in their middle and full of Marrow; they touch one ano­ther only at their Extremities, leaving spaces in their middle, in which lie the Musculi Interossei. In their upper end there is a Sinus which receives the Bones of the Wrist, and their lower Extremity is round, and is received into the Sinus of the first Bones of the Fingers.

The Bones of the Fingers.The Bones of the Fingers and Thumb are fifteen in each Hand, three to each Finger; they are a little convex and [Page 231]round towards the Back of the Hand, but hollow and plain towards the Palm, except the last where the Nails are. The order of their Disposition is called first, second, and third Phalanx. The first is longer than the second, and the second than the third. The upper Extremity of the first Bone of each Finger has a little Sinus which receives the round head of the Bones of the Metacarpus. The upper Extremity of the second and third Bones of each Finger hath two small Sinus's parted by a little Protuberance; and the lower Extremity of the first and se­cond Bones of each Finger has two Protuberances, divided by a small Si­nus. The two Protuberances are re­ceived into the two Sinus's of the up­per Extremity of the second and third Bones; and the small Sinus receives the little Protuberance of the same end of these same Bones. The first Bone of the Thumb is like to the Bones of the Metacarpus, and it is joined to the Wrist and second of the Thumb, as they are to the Wrist and first of the Fingers. The second Bone of the Thumb is like the first Bones of the Fingers, and it is joined to the first and third, as they are to the Bones of the Metacarpus, and second of the Fingers. The Fingers are moved [Page 232]side-ways, only upon their first Joint.

Ossa Sesa­moidaea.Besides these Bones, there are some small ones called Ossa Sesamoidaea, be­cause they resemble the Grains of Se­samum, they are reckoned about 12 in each Hand; they are placed at the Joints of the Fingers, under the Ten­dons of the Flexores Digitorum, to which they serve as so many Pulleys.

SECT. XIV. Of the Bones of the Thighs, Legs, and Feet.

THE Thigh has only one Bone, which is the longest of all the Bones of the Body, its Fibres are close and hard; it has a Cavity in its middle, 'tis a little convex and round on its foreside, but a little hollow, with a long and small ridge called Linea Aspe­ra on its backside. At its upper end it has three Epiphises which separate ea­sily in Children.

The first is its Extremity, which is a large and round head covered with a Cartilage, which is received into the Acetabulum Coxendicis, wherein it is tied by two Ligaments. The first is pretty large, and comes from the edge of the Acetabulum. The second is round and short; it comes from the bottom of the Acetabulum, and is in­serted [Page 233]in the middle of the round head; the Part immediately below this round head, which is small, long, and a little Oblique, is called its Neck. It makes an Angle with the Body of the Bone, by which means the Thighs are kept at a distance from one another, that the Muscles on the inside of the Thighs might lie the more conveniently with­out rubbing upon one another, or hurt­ing of the Privities. Besides this ob­liquity of the Neck of the Bone con­duces much to the strength of the Muscles of the Thigh; because it re­moves their Insertions from the Center of Motion.

Trochanter major.The second is called Trochanter major; it is a pretty big Protuberance on the External side of the Thigh Bone, just at the root of the Neck, it is rough, because of the Insertion of some Mus­cles in it. It has a small dent at its root, into which the Musculi Quadra­gemini and the Obturatores are inser­ted.

Trochanter minor.The third is called Trochanter minor; it is on the hind side of the Thigh Bone, a little lower and less than the other.

The lower Extremity of the Thigh Bone, which is articulated with the Tibia by Ginglimus, is divided in the middle by a Sinus into two Heads [Page 234]or Protuberances, the External and the Internal, which are received into the upper Sinus's of the Tibia; thorow the space which is between the hind Parts of these two Heads pass the great Ves­sels and Nerve which go to the Leg.

In the Knee there is a little round Bone, Patella. about two Inches broad, pretty thick, a little convex on both sides, covered with a smooth Cartilage on its foreside; it is soft in Children, but ve­ry hard in those of riper Years; it is called Mola, Patella, or Pan; over it pass the Tendons of the Muscles which extend the Leg, to which it serves as a Pulley for facilitating their Mo­tion.

In the Leg there are two Bones, Tibia. the inner and bigger is called Tibia or Fo­cile majus; 'tis hard and firm with a Cavity in its middle; 'tis almost tri­angular; its fore and sharp edge is called the Shin. In its upper Extre­mity it has two large Sinus's tipt with a soft and supple Cartilage called Car­tilago Lunata, and divided from one another by a small Production. The Sinus's receive the two Protuberances of the Thigh Bone, and the Produ­ction is received in the Sinus which divides these two Protuberances. On the side of this upper end it has a small knob, which is received into a [Page 235]small Sinus of the Fibula; and on its fore part a little below the Patella, it has another into which the Tendons of the Extensors of the Leg are inserted. Its lower Extremity, which is much smaller than its upper, has a remarka­ble Process which forms the inner An­kle, and a pretty large Sinus divided in the middle by a small Protuberance; the Sinus receives the convex Head of the Astragulus, and the Protuberance is received into the Sinus, in the con­vex Head of the same Bone. It has another shallow Sinus in the side of its lower end, which receives the Fi­bula.

The outer and lesser Bone is called [...], Fibula. Fibula or Focile Minus; though it be much smaller than the Tibia, yet 'tis nothing shorter. It lies in the outside of the Leg, and its upper end which is not so high as the Knee, re­ceives the lateral knob of the upper end of the Tibia, into a small Sinus which it has in its inner side. Its lower end is received into the small Sinus of the Tibia, and then it extends into a large Process, which forms the outer Ankle, embracing the External side of this Astragulus. The Tibia and Fibula touch not one another but at their ends; the space which they leave in their middle, is filled up by a strong [Page 236]membranous Ligament, and some Muscles which extend the Feet and Toes.

In the Foot we distinguish three Parts, the Tarsus, Metatarsus, and Toes.

The Bones of the Tarsus are the Talus.The Tarsus is the space between the Bones of the Leg and the Metatarsus; it is composed of seven Bones.

The first is called the Astragulus or Talus. In its upper Part it has a con­vex Head, which is articulated with the two Fociles of the Leg, by a Gin­glimus, being it is divided by a little Sinus, which receives the small Protu­berance in the middle of the Sinus of the Tibia. Its forepart which is also convex, is received into the Sinus of the Os Naviculare. Below, towards the hind part of its under side, it has a pret­ty large Sinus which receives the upper and hind part of the Os Calcis. But, towards the forepart of the same side, it has a Protuberance, which is received into the upper and forepart of the same Bone. Betwixt this Sinus and this Protuberance, there is a Cavity which answers to another in the Os Calcis, in which is contained an oily and mucous sort of Substance for moi­stening the Ligaments and facilitating the obscure Motion of these Bones when we go.

The second Bones of the Tarsus is the Calcaneus, Calcaneus. Os Calcis or Heel Bone, it is the biggest of the Bones of the Tar­sus. It lies under the Astragulus, to which it is articulated by Ginglimus, as we have now described. Behind, it has a large Protuberance which makes the Heel, and into which the Tendo A­chillis is inserted. And before it has a Cavity which receives a part of the Os Cubiforme.

The third is the Os Naviculare or Cymbiforme; Naviculare. it lies between the Astra­gulus and the three Ossa Cuneiformia. Behind it has a large Sinus, which re­ceives the fore convex Head of the first; and before, it is convex, distin­guished into three Heads, which are received into the Sinus's of the Ossa Cuneiformia.

Ossa Cunei­formia.The fourth, fifth, and sixth are cal­led Ossa Cuneiformia, because they are large above, and narrow below; they lie all three at the side of one another; their upper side is convex and their under hollow, by which means the Muscles and Tendons in the Sole of the Foot are not hurt when we go. At one end they have each a Sinus, which receives the Os Naviculare, and at the other they are joined to the three inner Bones of the Metatarsus; the inmost of these Bones is the [Page 238]biggest, and that in the middle the least.

The seventh Bone is called the Os Cubiforme, because of its Figure; it lies in the same rank with the Ossa Cunei­formia. Behind, it is joined to the Os Calcis, before, to the two outer Bones of the Metatarsus; and on its inside it is joined to the third Os Cuneiforme.

The Bones of the Metatarsus are five; Metatarsus. That which sustains the great Toe is the thickest, and that which sustains the next Toe is the longest; the rest grow each shorter than ano­ther. They are longer than the Bones of the Metatarsus, in other things they are like them, and they are arti­culated to the Toes, as they are to the Fingers.

The Bones of the Toes.The Bones of the Toes are fourteen. The great Toe hath two, and the rest have each three; they are like to the Bones of the Fingers, only they are shorter.

In the Toes there are ordinarily found twelve Ossa Sesamoidaea as in the Fingers.

SECT. XV. Of the Nails and Number of the Bones.

THE Nails which are upon the Ex­tremities of the Fingers and Toes, [Page 239]seem to be of the same Nature as the Hoffs of other Animals. If you take the Hooff carefully off a Horse, Ox, or Hog, you shall see that it is nothing but a bundle of small Husks which an­swer to so many Papillae of the Skin. From whence we may conclude, that the Nails are nothing but the covers or sheaths of the Papillae Pyramidales of the Skin on the Extremities of Fingers and Toes, which dry, harden, and lie close upon one another; their use is to defend the ends of the Fingers when we handle any hard or rugged Body.

Besides the Ossa Sesamoidaea, which are sometimes found to the Number of 48.

SECT. I. Of the Muscles of the Face.

THE Eye-brows have each a Muscle called Corrugator. It arises from the great Canthus of the Orbit, and terminates in the Skin about the middle of the Eye­brows. Some reckon this Pair only a Prolongation of the Frontales; their Name declares their Use.

The Nose has three Muscles. The first arises from the upper end of the two Bones of the Nose; and are in­serted into the upper Part of the Alae. They pull the Nose upwards.

The second Pair arise from the Os Maxillare, and are inserted into the sides of the Alae. They dilate the Nostrils.

The third Pair arise from the same Bone, above the Dentes Incisorii, and are inserted into the Extremities of the Alae, which they pull downwards.

The Muscles of the Lips are four Pro­per Pair.

The Incisivus, or Elevator Labii Su­perioris; it arises from the upper Part of the fourth Bone of the upper Jaw, and descending obliquely is inserted in­to the upper Lip above the Dentes Inci­sorii.

Its Antagonist is the Triangularis, or Depressor Labii Superioris; it ariseth from the lower edge of the lower Jaw, between the Massater and the Qua­dratus, and ascendeth by the Angle of the Mouth to the upper Lip.

The Caninus, or Elevator Labii In­ferioris; it ariseth from the fourth Bone of the upper Jaw, below the Incisiv [...]s; it descends and passes under the Inter­tion of the Zygomaticus, and is inserted into the under Lip.

Its Antagonist is the Quadratus, or Depressor Labii Inferioris; this is some thin, fleshy Fibres, which lie imme­diate under the Skin, upon the Chin; they arise from the edge of the fore­part of the under Jaw, and are inserted into the upper Lip.

There are three Muscles common to both the Lips.

The first and the second are Zygoma­tici, one on each side; they come from the Os Zygoma, and going obliquely they are inserted near the Angles of the Lips. When one of these Muscles act­eth, it draws both Lips obliquely to a [Page 243]side; they receive often some Fibres from the Caninus.

The third is the Orbicularis, or Sphin­cter Labiorum, it surrounds the Lips with Orbicular Fibres; when it acteth, it draws the Lips together.

There is one Muscle on each side common to the Lips and Cheeks, which is the Buccinator; it lies under the other Muscles; it makes the inner Substance of the Cheeks; its Fibres run from the Processus Coronae of the lower Jaw, to the Angle of the Mouth: And they adhere to the upper part of the Gums of both Jaws. Thorow its middle pass the upper Ductus Salivales; by this Mus­cle we contract the Cavity of our Mouth, and thrust the Meat between our Teeth.

The Muscles of the lower Jaw, are twelve Pair, six on each side.

The first is the Temporalis, or Crota­phites; it arises by a Semicircular fleshy beginning from a Part of the Os Fron­tis, from the lower Part of the Parie­talis, and upper Part of the Temporalis. From thence they go under the Zygo­ma, and gathering together as to their Centre, they are inserted by a short, but strong Tendon into the Processus Coronae of the lower Jaw.

The second is the Massater; it is a thick and short Musele; it arises from [Page 244]the Zygoma, and from the first Bone of the upper Jaw, and is inserted into the lower edge of the lower Jaw, from its External Angle to its middle. Its Fi­bres run in three Directions; those which come from the Zygoma run ob­liquely to the middle of the Jaw; and those from the first Bone of the upper Jaw cross the former, and run to the Angle of the lower Jaw, and the Fi­bres which are in its middle run in a perpendicular from their Origin to their Insertion. These two Muscles pull the Jaw upwards.

The third is the Pterigoidaeus Inter­nus; it arises from the Internal Part of the Processus Pterigoidaeus, and descends to be inserted into the Inferior Part of the Internal side of the lower Jaw, near its Angle. When this Muscle act­eth, it draweth the Jaw to a side.

The fourth is the Pterigoidaeus Ex­ternus; it ariseth from the External Part of the same Process, and goes backwards, to be inserted between the Processus Condiloides and the Coronae on the inside of the lower Jaw. This Muscle pulleth the lower Jaw for­wards.

The fifth is the Quadratus; this is a broad, membranous Muscle, which lies immediately under the Skin; it ariseth from the upper Part of the Sternum, [Page 245]from the Claviculae, and from the Acro­mium; it covereth all the Neck, and ad­heres firmly to the lower edge of the lower Jaw; and being produced it co­vers also the lower Part of the Cheeks. When this Muscle acteth, it pulleth the Cheeks and Jaw downwards.

The sixth is the Digastricus; it ari­seth fleshy from the upper Part of the Processus Mastoidaeus, and descending it contracts into a round Tendon, which passes thorow the Stylohyoidaeus; then it grows fleshy again, and ascends to the middle of the edge of the lower Jaw, where it is inserted. When this Mus­cle acteth, it pulleth the lower Jaw down.

SECT. II. Of the Muscles of the Head.

THE Head is lifted up, or pulled backwards by four pair of Muscles.

The first is the Splenius, which ari­seth from the four upper Spines of the Vertebrae of the Back, and from the four lower of the Neck, and ascending obliquely, it adheres to the upper trans­verse Processes of the Vertebrae of the Neck, and is inserted into the upper Part of the Occiput.

The second is the Complexus; it ari­seth from the transverse Processes of [Page 246]the Vertebrae of the Neck, and ascend­ing obliquely, it adheres to the Spines of the same Vertebrae, and is inserted into the Occiput: When one of these Muscles acteth, it moves the Head back­wards to one side.

The third is the Rectus Major, it ariseth from the Spine of the second Vertebrae of the Neck, and is inserted into the lower Part of the Occiput.

The fourth is the Rectus Minor; it lies under the Major; it cometh from the back Part of the first Vertebra of the Neck, and is inserted below the former. They nod the Head back­wards.

The Semicircular motion of the Head is performed by

The Obliquus Inferior, which comes from the Spine of the second Vertebra of the Neck, and is inserted into the transverse Process of the first.

The Obliquus Superior comes from the transverse Process of the first Ver­tebra of the Neck, and is inserted into the Lateral and Inferior Part of the Occiput.

The Mastoidaeus arises fleshy from the upper Part of the Sternum, and Extremity of the Claviculae, and as­cending obliquely, 'tis inserted into the back part of the Processus Mammilla­ris. When either of these Muscles act­eth, [Page 247]the Head turneth to the contrary side.

The Head is bended forwards by

The Rectus Internus, which arises from the forepart of the five Inferior transverse Processes of the Vertebrae of the Neck, and is inserted into the fore­most Appendix of the Occipital Bone, near its great hole.

The Rectus Internus minor, observed and described by that accurate Anato­mist Mr. Cooper, in his most exact Treatise of the Muscles; it lies on the forepart of the first Vertebra, like the Rectus Minor on the back part, and is inserted into the Anterior Appendix of the Os Occipitis, immediately under the former. These nod the Head forwards, being Antagonists to the last named Muscles.

Fallopius has described another Pair, which come from the transverse Pro­cesses of the first Vertebra, and is in­serted near the Processus Mammillaris; these last help to move the Head a lit­tle to one side.

SECT. III. Of the Muscles of the Neck.

THE Neck is bended and exten­ded; it is bended by two Pair of Muscles.

The first is the Longus, which is fa­stened to the Body of the five upper Vertebrae of the Back, and to all those of the Neck; but because the last are more moveable than the first, there­fore they are its Insertion, and those of the Back its Origination.

The Scalenus arises from the first and second Ribs and Part of the Claviculae; and ascending, it's inserted into all the transverse Processes of the Neck, ex­cept the first. This Muscle seems to be three; yet I will not encrease their number. It is perforated for the Pas­sage of the Veins, Arteries, and Nerves. Because the neck is more easily moved than that Part of the Ribs to which they are fastened; therefore it's justly reckoned amongst the benders of the Neck.

The Neck is extended by the Mus­culi Vertebrales, of which afterwards.

SECT. IV. Of the Muscles of the Scapula.

THE Scapula is moved backwards and forwards, upwards and down­wards by four Muscles.

The first is, the Serratus Minor An­ticus; it ariseth thin and fleshy, from the second, third, fourth, and fifth Su­perior Ribs, and ascending obliquely, [Page 249]it is inserted fleshy into the Processus Ca­rocoides of the Scapula, which it draws forwards; it helps also in Respiration.

The second is the Trapezius, or Cu­cullaris, because with its fellow it re­presents a Cowl; it arises from the Oc­ciput above the Splenius, from the Spines of the Vertebrae of the Neck, and from the eighth Superior of the Back, and is inserted into the Spine of the Scapula, to the Acromium, and Clavicle. It moves the Scapula obliquely upwards, directly backwards, and obliquely downwards, according to the three Directions of its Fibres.

The third is the Rhomboides, so cal­led from its Figure; it lies under the Cucullaris; it ariseth from the two In­feriour Spines of the Neck, and four Superior of the Back, and is inserted fleshy into the whole basis of the Sca­pula, which it draws backwards.

The fourth is the Levator Scapulae; it arises from the second, fourth, and fifth transverse Processes of the Neck, by so many distinct beginnings, which unite, and are inserted into the Superior Angle of the Scapula, which it draws upwards. It is also called Musculus Patientiae; because those who are any­ways grieved use it.

These Muscles may move the Arm, as those of the Arm move it, because [Page 250]of the Connexion of the two Bones. They help also in Respiration.

SECT. V. Of the Muscles of Respiration, and of the Benders and Extensors of the Ver­tebrae.

THE Cavity of the Thorax is dila­ted and contracted in Respiration by twenty nine Pairs of the Muscles: Fourteen Pair dilate it, and as many contract it: And one Pair, viz. the Diaphragma, helps both in the one and other; this last we have described al­ready.

The Muscles which dilate the Thorax in Inspiration are

The Intercostales Externi; they are eleven on each side situated between the Ribs, they arise from the lower edges of each Superior Rib, and are in­serted into the upper edges of each Infe­rior Rib; their Fibres descend obliquely from the back part forwards.

The Subclavius arises from the low­er side of the half of the Claviculae that is nearest the Acromium, and de­scends obliquely to be inserted into the upper Part of the first Rib near the Sternum.

The Serratus Anticus Major; it comes from the whole basis of the Scapula, [Page 251]and is inserted into the seven true Ribs, and first of the false Ribs by so many distinct Portions, which represent the teeth of a Saw. The Obliquus Descen­dens of the Abdomen lie between the spaces of its lower Indentations.

The Serratus Posticus Superior; it ari­seth by a broad and thin Tendon from the two Inferior Spines of the Vertebrae of the Neck, and the three Superior of the Back, and growing fleshy, 'tis in­serted into the second, third, and fourth Ribs by so many distinct Indentations.

When all these Muscles act, they draw the Ribs upwards, bringing the Ribs to right Angles with the Vertebrae; and consequently the Cavity of the Thorax must be wider and shorter: but because at the same time the Diaphragma con­tracts and becomes plain, therefore the Cavity is also longer.

The Muscles which contract the Ca­vity of the Thorax, are

The Intercostales Interni; they have the same Situation, Origination, and Insertion as the Externi, with this dif­ference, that their Fibres run contrary to the Fibres of the Externi, viz. from the forepart backwards. It is more probable they also serve to dilate the Thorax; for when two Parts are equal­ly drawn to one another, the more moveable, viz. the lower Ribs must [Page 252]approach the less moveable, viz. the upper Ribs, considering also that a greater strength is required to draw up the Ribs, than to pull them down, to their natural Position.

The Triangularis arises from the lower Part of the inside of the Sternum, and is inserted into the Cartilages where they join the Bones of the fourth, fifth, sixth, and sometimes seventh true Ribs.

The Serratus Posticus Inferior rises by a broad and thin Tendon from the three Inferior Spines of the Vertebrae of the Back, and from the two Superior of the Loins, its Fibres ascending ob­liquely grow fleshy, and are inserted by four Indentations into the four last Ribs.

The Sacrolumbus; it ariseth fleshy from the Superior Part of the Os Sacrum, Posterior Part of the Spine of the Ili­um, and from all the transverse Pro­cesses of the Vertebrae of the Loins; It gives a small Tendon to the Posterior Part of each Rib near its root.

The Muscles which extend the Ver­tebrae are the Sacer, the Spinatus, Semi­spinatus and Transversalis Colli, all which M. Du Verney reckons but one, which he calls Vertebralis, of which one Plan arises from the Spines of the Os Sacrum and of the Vertebrae of the Loins, and is inserted into the Spines of the Vertebrae [Page 253]of the Back; another arises from the Spines of the Back, and is inserted into those of the Neck: Under these there are others which go from the trans­verse Processes of the Inferiour Verte­brae, to the Spines of the Superior Ver­tebrae, and as many which go from the oblique Processes to the Superior Spines, of which ordinarily the Fibres of three oblique Processes make a Tendon to one Spine.

It seems to be as proper to make the Extensors of the Vertebrae, one com­pound Muscle as three; for in effect, they are almost as many really distinct Muscles, as there are oblique, transverse and acute Processes in the Vertebrae; but because this would multiply the num­ber of the Muscles, and cause a great confusion if they were to have all di­stinct Names, therefore it is better to call them by the Name of Musculi Vertebrales.

The Vertebrae of the Neck are bended by two Pair of Muscles, which have been already described; the Vertebrae of the Back have no Benders, and those of the Loins are bended by the Muscles of the Lower Belly, and by one pro­per Pair which is called the Psoas Par­vus; it arises fleshy from the sides of the upper Vertebrae of the Loins, and it has a thin and broad Tendon which [Page 254]embraces the Psoas of the Thigh, and which is inserted into the Os I [...]n [...]mina­tum, where the Os Pubis and Ilium join together.

SECT. VI. Of the Muscles of the Humerus, or Arm.

THE Arm moves five different ways, upwards, downwards, forwards, backwards, and round.

The Arm is lifted upwards by the Deltoides, Supra spinatus, and Coraco­brachialis.

The Deltoides is of a triangular Fi­gure, it comes from all the Spina Sca­pulae, from the Acromium, from the External half of the Clavicula, from all these places its Fibres drawing toge­ther, pass above the Articulation of the Humerus, and are inserted by a short Tendon, four fingers below the Head of the same Bone, almost on its Ex­ternal side. Steno shews that this Mus­cle is composed of twelve simple Mus­cles: according to the direction of its Fibres, it pulls also the Arm a little forwards and backwards.

The Supra spinatus rises fleshy from all the basis of the Scapula, that is above the Spine. It fills all that space between the upper side of the Scapula and its Spine, to which two it is also [Page 255]attached; it passes above the Acromium, the Articulation of the Humerus, and is inserted into the Neck of the Humerus, which it embraces by its Tendon.

The Coracobrachia [...]is rises from the Processus Coracoides Scapulae, by a tendi­nous beginning, and passing over the Articulation, it is inserted into the mid­dle and Internal Part of the Hume­rus.

The Teres Major and the Latissimus Dorsi pull the Arm downwards.

The Teres Major rises from the lower Angle of the Scapula, and is inserted with the following a little below the Head of the Humerus.

The Latissimus Dorsi or Aniscaptor, with its fellow, covers almost all the Back. It hath a thin and large tendi­nous beginning, which comes from the Posterior Part of the Spine of the Ili­um, from the Superior Spines of the Os Sacrum, from all the Spines of the Ver­tebrae of the Loins, and from the seven lower of the Thorax; it passes by the Inferior Angle of the Scapula, to which it is sometimes attached, and is inserted with the Teres Major, by a strong and broad Tendon.

The Pectoralis moves the Arm for­wards; it ariseth by a fleshy and Semi­circular beginning, from the inner half of the Clavicula, from the Six Supe­rior [Page 256]Ribs; it covereth a great part of the Breast, and is inserted by a short, but strong and broad Tendon, into the upper and inner Part of the Humerus, between the Biceps and Deltoides. Its Fibres near their Insertion decussate each other. Those which come from the Clavicle and first Ribs, are on the lower side of the Tendon; and those from the inferior Ribs are on the up­per side of the Tendon.

The Arm is drawn backwards by the Infra spinatus, the Transversalis, and the Subscapularis.

The Infra spinatus covers all the space that is between the Spine of the Sca­pula, and its Inferior side; and passing between the Spine and the Teres Mi­nor; 'tis inserted into the Neck of the Humerus.

The Transversalis, or Teres Minor, comes from the Inferior edge of the Scapula, upon which it runs between the former and the Teres Major, and is inserted into the Neck of the Hu­merus.

The Subscapularis covers all the In­ternal side of the Scapula; it rises fleshy from its basis, from its upper and lower Costa, and is inserted into the Neck of the Humeras. It draweth the Arm close to the Ribs.

The Tendons of these three last Muscles, surround the Articulation of the Humerus. When all these Muscles move successively, they move the Arm circularly.

SECT. VII. Of the Muscles of the Cubitus and Radius.

THE Cubitus is bended and exten­ded by six Muscles; the Biceps and Brachiaeus Internus bend it; the Longus, Brevis, Brachiaeus Externus, and the Anconeus extend it.

The Biceps is so called, because it hath two Heads, of which one rises from the upper edge of the Cavity of the Head of the Scapula. This Head is round and tendinous, and is enclosed in the Channel in the Head of the Humerus. The other arises from the Processus Co­racoides; it is broad and tendinous, and both together unite about the middle and forepart of the Arm, and make one Belly, which is inserted, by a strong and round Tendon, into the tubercle at the upper end of the Radius: Some of the Fibres of this Tendon form a large and thin Aponeurosis which co­vers all the Muscles of the Radius and Fingers externally. Care ought to be taken in Blood-letting, not to cut across, [Page 258]but according to the length of the Fi­bres of this Aponeurosis.

The Brachiaeus Internus, lies partly under the Biceps; it arises by a fleshy beginning from the middle and Inter­nal Part of the Humerus, and is in­serted into the upper and forepart of the Cubitus, by a very short, but strong Tendon.

The Longus is the first of those which extend the Cubitus; it ariseth from the Inferior Costa of the Scapula, nigh its Neck, and passeth between the two round Muscles; it descendeth upon the backside of the Humerus, where it joins with the two following.

The Brevis arises from the Superior and Posterior Part of the Humerus.

The Brachiaeus Externus arises about the middle and Posterior Part of the Humerus. These three join their fleshy Fibres together, and being externally tendinous, they cover all the Elbow, and are inserted into the Olecranium.

The Anconeus is a small Muscle which arises from the backpart of the Extre­mity of the Humerus, passes over the Elbow, and is inserted into the Lateral and Internal Part of the Ʋlna, about three or four fingers breadth below the Olecranium.

The Radius hath four Muscles, two Pronatores, which turn the Palm of the [Page 259]Hand downwards, they are the Rotun­dus and the Quadratus, and two Supi­natores, which turn the Palm upwards, they are called Longus and Brevis.

The Rotundus arises fleshy from the Internal Extuberance of the Humerus, and goes obliquely to be inserted into the middle and External Part of the Radius.

The Quadratus arises by a broad and fleshy beginning from the lower and Internal Part of the Ʋlna; it passes over the Ligament that joins the Ra­dius to the Ʋlna, and is inserted as broad as its beginning into the External and lower Part of the Radius.

The first of the Supinatores is the Longus, it ariseth by a fleshy beginning, three or four fingers breadth, above the External Extuberance or the Humerus. It lies all along the Radius, to whose Inferior and External Part it is inserted by a pretty broad Tendon.

The second is the Brevis; it cometh from the External and upper Part of the Ʋlna, and passing round the Ra­dius, 'tis inserted into its upper and forepart, below the Tendon of the Biceps.

SECT. VIII. Of the Muscles of the Palm of the Hand and of the Wrist.

THE Muscles of the Palm of the Hand are two.

The first is that which is commonly known by the Name of Palmaris; it ariseth from the Internal Extuberance of the Humerus, and by a long and slender Tendon it passes above the Li­gamentum Annulare to the Palm of the Hand, where it expands it self into a large Aponeurosis, which cleaves close to the Skin above, and to the sides of the Bones of the Metacarpe below, and to the first Phalanx of the Fingers, by which means it makes four Cases for the Tendons of the benders of the Fin­gers to pass thorow. This Muscle is sometimes wanting, but the Aponeurosis is always there.

The second may be called Palmaris Brevis; it lies under the Aponeurosis of the first; it arises from the Bone of the Metacarpus that sustains the little Finger, and from that Bone of the Carpus that lies above the rest. It goes transversly, & is inserted into the eighth Bone of the Carpus. The first assists the Hand to grasp any thing closely, and the second makes the Palm of the Hand Concave.

The Muscles of the Wrist are four, two Internal for bending of it, and two External for extending it.

The first is the Cubitaeus Internus; it arises from the Internal Extuberance of the Humerus and upper Part of the Ʋlna, upon which it runs all along, till it pass under the Ligamentum Annu­lare, and is inserted by a strong and short Tendon into the fourth of the first Order of the Carpus.

The second is the Radiaeus Internus, which comes from the same Part with the former, and lying along the Ra­dius, it is inserted into the first Bone of the Metacarpus that sustains the fore­finger. These two Muscles bend the Wrist.

The third, which is the first of the Extensors, is the Cubitaeus Externus; it cometh from the External Extube­rance of the Humerus, and passing its Tendon under the Ligamentum Annu­lare, 'tis inserted into the fourth Bone of the Metacarpus that sustains the little Finger.

The fourth is the Radiaeus Externus or Bicornis, which is two distinct Mus­cles; the first arises from above the External Protuberance of the Hume­rus, and the second from the lower-most Part of the External Protube­rance. They both lie along the Exter­nal [Page 262]Part of the Radius; they pass un­der the annular Ligament, and the one is inserted into the Bone of the Meta­carpus that sustains the Fore-finger, the other to that which sustains the Middle-finger; these two extend the Wrist.

SECT. IX. Of the Muscles of the Fingers.

THE Fingers are bended and exten­ded, they are drawn to, and from the Thumb, by several Muscles. The Muscles which bend them are the Sub­limis and the Profundus.

The Sublimis, otherwise called Per­foratus, arises from the Internal Pro­tuberance of the Humerus, and from the upper and forepart of the Radius: It divides into four Parts which send four Tendons, which pass under the annular Ligament to be inserted into the upper Part of the second Phalanx of each of the four Fingers. Each of these Tendons as they pass the first internode of the Fingers, have a slit in their mid­dle for the passage of the Tendons.

The Profundus which lies under the Sublimis; it ariseth fleshy from the up­per Part of the Ʋlna, and from the Ligament that joins this Bone to the Radius; the lower Part of its Body is outwardly tendinous; it divides into [Page 263]four round Tendons, which pass under the annular Ligament, and thorow the slits of the former Tendons, to be in­serted into the third Bone of the Fin­gers.

These Muscles have this in particular, that the Tendons of the uppermost give passage to the Tendons of the lower. And their Tendons upon the Palm of the Hand are enclosed in cases from the Aponeurosis Palmaris, and upon the Fingers in strong membranous ca­ses which are fixt to the sides of each Finger.

The Extensor Digitorum Communis, arises from the External Protuberance of the Humerus, and at the Wrist it divides into three flat Tendons, which pass under the annular Ligament, to be inserted into all the Bones of the fore, middle, and ring Finger. These Ten­dons near the first internodes of the Fingers give some tendinous Fibres to each other, and some also to the In­terossei.

The Lumbricales, or Vermiculares are small Muscles which rise from the Ten­dons of the Profundus, and are inserted into the first internodes of each Finger. On their Internal sides next the Thumb, they assist in bending the first Joint of the Fingers.

The Interossei, some reckon six, and others, more justly, eight; they are contained betwixt the spaces of the Bones of the Metacarpus; the one half of them lies betwixt the spaces that these Bones leave towards the Palm of the Hand; they are the Internal Inte­rossei; they arise from the upper Part of the Bones of the Metacarpus next the Carpus, and they are inserted on the Internal sides of the first Bones of the Fingers, with the Lumbricales; they are the Adductores Digitorum, for they bring the Fingers to the Thumb. The other half are contained in the spaces that the Bones of the Metacar­pus leave on the Back of the Hand, they rise from the upper Part of the Bones of the Metacarpus next the Car­pus, and they are inserted on the Ex­ternal sides of the first Bones of the Fingers, and not on the same side with the former, as Mr. Cooper alledges; and these are the Abductores Digitorum, for they draw the Fingers from the Thumb.

The Thumb is bended by two Mus­cles. The first arises from the Internal Extuberance of the Humerus, from the middle and inner Part of the Radius, by two different Orders of fleshy Fi­bres: and passing under the Ligamen­tum Annulare, its Tendon is inserted into [Page 265]the third Bone of the Thumb. The second arises from the Bones of the Carpus, from the annular Ligament, and is inserted into the second internode of the Thumb. These two Muscles are called Flexores Pollicis.

It is extended by two Muscles, which are the Longus and Brevis.

The Longus arises from the upper, and External Part of the Ʋlna; it passes obliquely over the Tendon of the Ra­diaeus Externus, and is inserted near the second joint of the Thumb. This may be separated into two distinct Muscles, and some reckon it so, for its Tendon is also double.

The Brevis arises a little lower than the former from the Ʋlna, and is inserted into the third Bone of the Thumb.

The Tenar draws the Thumb from the Fingers; it makes that Part which is called Mons Veneris; it ariseth from the Ligamentum Annulare, and first Bone of the Carpus, and is inserted into the External side of the Thumb.

The Antitenar draws the Thumb to the Fingers; it ariseth from the Bone of the Metacarpus that sustains the Fore-finger, and is inserted into the first Bone of the Thumb.

The Abductor Indicis arises from the forepart of the first Bone of the Thumb, [Page 266]and is inserted into the Bones of the Fore-finger; it draws this Finger to the Thumb.

The Index hath a particular Extensor, which comes from the middle andex­ternal Part of the Ʋlna; it passeth under the annular Ligament, and is inserted into the third Bone of the Fore-finger, where it joins the Extensor Communis.

The little Finger hath two p [...]oper Muscles, the one draws it from the other Fingers, the other extends it. The first is called Hypotenar; it ariseth from the fourth Bone of the second rank of the Bones of the Carpus, and from the Ligamentum Annulare, and is inserted externally into the first Bone of the little Finger; this draws it from the other Fingers.

The Extensor of the little Finger ari­ses from the External Protuberance of the Humerus, and from the upper Part of the Ʋlna; it passeth under the an­nular Ligament, and is inserted into the third Bone of the little Finger.

SECT. X. Of the Muscles of the Thigh.

THE Thigh is bended and extended, moved outwards and inwards ob­liquely and circularly by thirteen Mus­cles.

It is bended by the Psoas, Iliacus, and Pectineus.

The Psoas arises from the Internal side of the transverse Processes of the Vertebrae of the Loins, within the Abdomen, and descending upon Part of the Internal side of the Ilium; it is inserted into the lower Part of the little Trochanter.

The Iliacus arises from the Internal Cavity of the Os Ilium, and descending it joins with the former, with which it is also inserted.

The Pectineus arises from the Exter­nal Part of the Os Pubis, and is inserted a little below the lesser Trochanter.

The Thigh is extended by the Glu­taeus Major, Medius and Minor.

The Glutaeus Major arises Semicircu­larly from the Os Coccygis, the Spines of the Sacrum, and from the Spine of the Ilium, and descending 'tis inserted in­to the Linea Aspera, four fingers breadth below the great Trochanter.

The Glutaeus Medius arises from all the Spine of the Ilium under the for­mer, and is inserted into the Superior and External Part of the great Tro­chanter.

The Glutaeus Minor arises from the lower Part of the External side of the Ilium, under the former, and is inser­ted at the Superior Part of the great Trochanter.

The Thigh is moved inwards, or they are both brought together by the Tri­ceps which hath three Originations and three Insertions, and may be divided into three Muscles.

The first arises from the Os Pubis, and is inserted above the second into the Linea Aspera of the Thigh Bone.

The second arises from the lower Part of the Os Pubis, and is inserted about the middle of the Linea Aspera.

The third arises from the Os Pubis, where it joins the Os Ischium, and is inserted from a little below the second to the Internal and lower Apophisis of the Thigh Bone: When they act, they pull the Thigh Bone inwards, and turn it a little outwards.

The Thigh is turned outwards by the Quadrigemini.

The first is, the Pyriformis, or Iliacus Externus; it arises round and fleshy from the Inferior and Lateral Part of the Os Sacrum, and is inserted with

The second and third called Gemini, which arise from the Protuberance of the Ischium, and are inserted with the first in the dent at the root of the great Trochanter.

The fourth is the Quadratus, it comes from the Protuberance of the Ischium, and is inserted into the outside of the great Trochanter.

The Thigh is moved circularly and obliquely when these Muscles act suc­cessively, but particularly by the two Obturatores.

The Obturator Internus comes from the Internal Circumference of the hole that is between the Ischium and Pubis, and passing thorow the Sinuosity of the Ischium, it is inserted into the dent of the great Trochanter. Its Tendon lies between the Gemini; it turns the Thigh to the outside.

The Obturator Externus comes from the External Circumference of the same hole as the former; it embraces the Neck of the Thigh Bone, and passes under the Quadratus to the small Ca­vity of the great Trochanter.

SECT. XI. Of the Muscles of the Leg.

THE Leg is bended by four Muscles, and extended by four others. The Muscles which bend it are,

The Seminervosus, which arises from the Protuberance of the Ischium, and is inserted by a round Tendon into the Internal Part of the Epiphisis of the Tibia.

The Semimembranosus arises tendi­nous from the Protuberance of the Is­chium, immediately below the former, [Page 270]and is inserted by a large Tendon into the upper and back Part of the Tibia.

The Biceps, so called, because it has two Heads, of which one comes from the tuberosity of the Ischium, the other from the middle of the Linea Aspera, both which join together, and are in­serted by one Tendon, into the Superior and External Part of the Perone.

The Gracilis arises from the union of the Os Pubis and Ischium, and de­scending by the inside of the Thigh, it grows tendinous, and is inserted into the Superior and Internal side of the Tibia.

The Leg is extended by four Muscles, which are

The Rectus; it arises from the lower Part of the Spine of the Ilium, and descending between the two following, it's inserted with them.

The Vastus Externus, which comes from the root of the great Trochanter, and Part of the Linea Aspera.

The Vastus Internus, which arises from the root of the lesser Trochanter.

The Crureus, which comes from the forepart of the Thigh Bone, between the great and lesser Trochanter, and lying close upon the Bone, it joins its Tendon with the three former, which all together make one broad Tendon, which passes over the Patella, and is [Page 271]inserted into the little tuberosity on the upper and forepart of the Tibia.

The Leg is moved obliquely by three Muscles.

The Longus or Sartorius; it arises from the Inferior Part of the Spine of the Ilium, and running obliquely by the inside of the Thigh, is inserted into the Internal side of the Tibia, three or four fingers breadth below its upper Extremity. By this Muscle we throw one Leg and Thigh across another.

The Poplitaeus; it arises from the Ex­ternal and Inferior Protuberance of the Thigh Bone, and passing over the Joint obliquely is inserted into the Superior and Internal Part of the Tibia. This assists in bending of the Leg, and turns it a little inwards.

The Membranosus, or Fuscia Lata, which arises fleshy from the forepart of the Spine of the Ilium, and a little below it becomes membranous or ten­dinous, and covers almost all the Mus­cles of the Thigh and Leg down to the Foot. This Muscle helps in extending of the Leg, and turns the Leg a little outwards.

SECT. XII. Of the Muscles of the Foot.

THE Foot is bended by the Tibiulis and Peronaeus Anticus.

The Tibialis Anticus arises fleshy from the upper and forepart of the Tibia, and adhering to the External side of the Tibia, as it descends it passes under the Ligamentum Annulare, and is inser­ted by two Tendons into the first Os Cuneiforme, and into the Os Metatarsi that sustains the little Toe.

The Peronaeus Anticus is joined to the Posticus, at its Origination, which is from the upper and External half of the Perone, and running thorow the Channel, which is in the External An­kle, 'tis inserted into the Os Metatarsi that sustains the great Toe.

The Foot is extended by four Muscles.

The first and second are the Gasteroc­nemius or Gemellus, which with the Soleus, make the Calf of the Leg, the one ari­ses from the back Part of the Internal Protuberance of the Thigh Bone, the other from the same Part of the Ex­ternal Protuberance of the same Bone; they have two large fleshy Bellies, which join and make one Tendon with the following, which is inserted into the Os Calcis.

The third is the Soleus, which lies under the former; it arises from the upper and back Part of the Tibia and Perone, and descending it joins its Ten­don with the former. The Tendon of these three Muscles is big, and strong, called Tendo Achillis.

The fourth is the Plantaris; it has a fleshy Origination from the back Part of the External Protuberance of the Thigh Bone, and descending a little way between the Gemellus and Soleus, it be­comes a long and slender Tendon, which marches by the inside of the great Ten­don, and at the Sole of the Foot it is expanded into a large Aponeurosis, which has the same use, situation, and con­nexion, as that of the Palm of the Hand.

The Foot is moved side-ways by two Muscles.

The Tibialis Posticus, which arises from the Superior and back Part of the Tibia and Fibula, and Membrane that ties them together, and descending by the hind Part of the Tibia, it passes thorow the Fissure of the inner An­kle, and is inserted into the under side of the Os Naviculare; it moveth the Foot inwards.

The Peronaeus Posticus arises from the Superior and External Part of the Pe­rone, and descending it passes thorow the Fissure of the External Ankle un­der the Sole of the Foot, to be inserted into the Os Metatarsi, that sustains the great Toe. When this Muscle acteth, it pulleth the Foot outwards.

SECT. XIII. Of the Muscles of the Toes.

THE four lesser Toes are bended, and extended, and moved side-ways. They are bended by the Profundus and Sublimis.

The Profundus arises from the upper and back Part of the Tibia, and passing under the inner Ankle, and Ligament that ties the Tibia and Os Calcis toge­ther, it divides into four Tendons, which pass thorow the holes of the Sublimis, are inserted into the third Bones of each lesser Toe. There is a Massa C [...]n [...]a that arises from the Os Calcis, and which joins the Tendons of this Muscle where the Lambricales begin.

The Sublimis or Flexor Brevis arises from the inner and lower Part of the Os Calcis, and is inserted by Four Tendons into the second Phalanx of each Toe. These Tendons are perforated to give way to the Tendons of the Profundus.

The Toes are extended by the Longus and Brevis.

The Longus comes from the Superior and External Part of the Tibia, and from the upper Part of the Fibula, and being divided into four Tendons, it passes under the Ligamentum Annulare, and is inserted into the third Bones of the lesser Toes.

The Brevis lies under the Tendons of the former, and arises from the Exter­nal and forepart of the Os Calcis▪ and is inserted by four Tendons into the se­cond Phalanx of the Toes. These Ten­dons cut the Tendons of the former at acute Angles.

The four Lumbricales arise from the Tendons of the Profundus, and are inser­ted into the inside of the lesser Toes.

The eight Inter [...]ssei, which lie be­twixt the Bones of the Metatarsus, have the fame situation, use, origination, and insertion, as those of the Iland.

The Abd [...]ctor Mi [...]i [...]i Digiti arises from the External Part of the Os Cal­cis, and lying upon the outside of the Os Metatarsi, that sustains the little Toe, 'tis inserted into the upper Part of the first Bone of the same Toe Exter­nally.

The great Toe is bended, extended, and moved side-ways by several Mus­cles.

The Flexor Pollicis arises from the upper and back Part of the Fibula, and passing by the inner Ankle, it's inserted into the last Bone of the great Toe.

The Extensor Pollicis arises from near the upper half of the Perone forwardly, and passing under the Ligamentum An­nulare, is inserted into the last Bone of the great Toe.

The Tenar or Abducens Pollicis arises from the Os Calcis, and from the Os Metatarsi, that sustains the great Toe, and is inserted into the External side of the first Bone of the great Toe.

The Antitenar or Adductor Pollicis arises from the Inferior Part of the third Os Cuneiforme, and passing ob­liquely is inserted into the inside of the first Joint of the great Toe.

The Adductor Indicis arises from the first Bone of the great Toe, and is inser­ted into the sides of the Bones of that Toe next the great Toe.

The Transversalis comes from the Bone of the Metatarsus that sustains the little Toe, and passing across the other Bones, 'tis inserted into the inside of the first Bone of the great Toe. Its use is, to bring all the Toes close to one another.

SECT. I. Of the Nerves in General.

A Nerve is a long and small bun­dle of very fine Pipes, or hollow Fibres, wrapt up in the Dura and Pia Mater; which last not only covers them all in common, but it also encloses every Fibre in particular.

The Medullary Substance of the Brains, is the beginning of all the Nerves; and 'tis probable that each Fibre of the Nerves answers to a par­ticular Part of the Brain at one end, and to a particular Part of the Body at its other end, that whenever an Im­pression is made upon such a Part of the Brain, the Soul may know that such a Part of the Body is affected.

The Nerves do ordinarily accompa­ny the Arteries thorow all the Body, that the Animal Spirits may be kept warm and moving by the continual heat and pulse of the Arteries. They [Page 288]have also Blood-Vessels as the other Parts of the Body; these Vessels are not only spread upon their Coats, but they run also amongst their Medullary Fibres, as may be seen amongst the Fibres of the Retina. Where-ever any Nerve sends out a branch, or receives one from another, or where two Nerves join together, there is generally a Gan­glio or Plexus either less or more, as may be seen at the beginning of all the Nerves or the Medulla Spinalis, and in many other places of the Body.

SECT. II. Of the Nerves which come immediately out of the Skull.

THE Nerves are divided into those which come immediately out of the Skull, and those which come out between the Vertebrae. The first sort come from the Medulla Oblongata, which has been already described, and they are ten Pair.

Nervi Ol­factorii.The first Pair are called Nervi Ol­factorii; they rise from the basis of the Corpora Striata, and passing thorow the little holes of the Os Cribriforme, they are spread upon the Membrane which covers the Os Spongiosum.

The second are called Optici, Optici. they rise partly from the Extremities of [Page 289]the Corpora Striata, and partly from the Thalami Nervorum Opticorum, which last they almost embrace; from thence approaching one another, they unite above the Cella Turcica, and immedi­ately dividing again, they pass thorow the foremost holes of the Os Sphaenoides into the Orbit, where piercing the Globe of the Eye, their Medullary Fi­bres are spread upon the glassy Hu­mour.

Oculorum Motores.The third are called Oculorum Mo­tores, they arise from the Medulla Ob­longata on each side of the Infundibu­lum, and the Carotidal Arteries lie be­tween them; from thence passing tho­row the Foramina Lacera of the Os Sphaenoides, they give a branch, which, with a branch of the fifth Pair, forms a considerable Plexus, which sends out several twigs which embrace the Op­tick Nerve, and are spent on the Tu­nicles of the Eye; they give a branch to the Muscles called Attollens, De­primens, and Obliquus Minor of the Globe.

Pathetici.The Fourth Pair are called Pathetici, that rise from a small Medullary Cord that is behind the Testes; they go down upon the sides of the Medulla Oblongata, and passing under the Dura Mater by the sides of the Cella Tur­cica, they go thorow the Foramina La­cera, [Page 290]and are wholly spent on the Ob­liquus Major.

The fifth Pair.The fifth Pair rise from the forepart of the Processus Annularis; they are the biggest Pair of the Brain; they give Nerves to the Dura Mater; each of them divides into three branches, of which the foremost is called Ramus Ophthalmicus, because it passes thorow the Foramen Lacerum into the Orbit, where it divides into two branches. The first sends out a branch which joins a branch of the Motores, and forms the Plexus Ophthalmicus. The rest of this first branch passes over the Globe of the Eye, gives some twigs to the Glandula Lachrymalis, and goes out at the hole of the Os Frontis above the Circumference of the Orbit, where it is distributed in the Skin and Frontal Muscles. The second branch of the Ramus Ophthalmicus goes under the Muscle Superbus, and passes out at the hole called Orbiter Internus, and is di­stributed in the Internal Nose.

The second branch of the fifth Pair, which passes out at the third hole of the Os Sphaenoides, divides into three branches, of which one piesces the hind­side of the Os Maxillars, and gives twigs to the Teeth of the Upper Jaw; all the rest of it comes out at the hole in the foreside of the same Bone under [Page 291]the Orbit, and is distributed in the Cheeks and Nose. Another passes un­der the Processus Zygomaticus, and is distributed in the temporal Muscle, and the third is distributed in the Palate and Muscles of the Pharynx.

The third branch of the fifth Pair passes thorow another hole of the Os Sphaenoides, and then it divides into two branches, the first of which is again divided into four branches, of which the first passes between the Condile and the Corone of the lower Jaw to the Massater. The second is distributed in the Crotaphites. The third passes under the Processus Zygomaticus to the Buc­cinator, Glands of the Cheeks and upper Lip. And the fourth passes from be­hind the Condile of the lower Jaw, where it joins the Pars Dura over the Jaw, and is distributed in the Face. The second branch is divided into three others. The first passes between the Pterigoidaeus Externus and the Inter­nus; and towards the Angle of the lower Jaw, it sends out a branch which makes the Chorda Tympani, which goes also to the Muscles of the Malleolus, and then it joins the Portio Dura be­fore it comes out of the Cranium, the rest is spread on the Chin. The second goes along the sides of the Tongue, sends out several branches which join [Page 292]the ninth Pair. It gives also some twigs to the Glandulae Sublinguales, to the Muscles of the Tongue and Os Hyoides. The third goes to the teeth of the lower Jaw by the holes in its inside.

The sixth Pair.The sixth Pair of Nerves rise from the sides of the Processus Annularis. This is a small Nerve which passes straight thorow the Foramen Lacerum, and is wholly spent on the Musculus Abducens. But a little before it enters the Orbit, it casts back a branch which alone makes the root of the Intercostal Nerve. It passes out of the Skull by the same passage the Carotidale Artery enters. As soon as it is come out of the Skull, it with a branch of the tenth Pair, and of the first and second of the Vertebrae of the Neck, forms a large Plexus called Cervicalis. Below this, it receives a branch made of a twig of the tenth Pair, and of the first of the Neck. As it descends above the Musculus Scalenus, and below the eighth Pair, it receives a branch from each of the Vertebral Nerves. When it comes to the Clavicula, it divides into two branches, of which one passes above the Axillary Artery and the other un­der it, and then they immediately join again; they, with a branch of the first Pair of the Back, form a pretty large [Page 293] Plexus at this place; and sometimes before (for it observes no regularity) it casts out a branch, which, with a branch of the eighth Pair, forms the Plexus Cardiacus; then it goes down the Cavity of the Thorax, under the Pleura, near the Vertebrae, and as it passes by, it receives a branch from every Pair of the Back, by which it grows bigger and bigger. As it goes out of the Tho­rax it divides into several branches, of which the three Superior in the right side form the Plexus Hepaticus, and in the left the Plexus Splenicus. These Plexus's furnish Nerves to the Kidneys, to the Pancreas, to the Caul, to the lower Part of the Stomach, to the Spleen, to the Liver, to the Mesentery, to the Intestines; and their branches form a large Net upon the Mesenterick Arteries, called Plexus Mesentericus. The Inferior branches as they go down upon the Vertebrae of the Loins, receive a branch from the first of the Loins, and they send out some branches which join those of the Superior branches which go to the Guts, and which form the Net upon the Mesenterick Arteries. Then they go down into the Bason, and form a large Plexus above the streight Gut, to which it gives Nerves, as also to the Bladder, Vesiculae Seminales Prostratae in Men, and to the Womband Vagina in Women.

Nervus Au­ditorius.The seventh Pair is the Nervus Audi­torius; it arises from the hind part of the Processus Annularis; it enters the hole in the inner Process of the Os. Pe­trosum; it divides into two branches; that which is soft is called Portio Mollis, and it is distributed in the Labyrinth Cochlea, and Membranes which cover the Cavities of the Ear. That which is hard, is called Portio Dura; it goes out of the Ear by that hole which is between the Processus Mastoides and Styloides; it divides into two branches, of which one goes to the Muscles of the Tongue, or Os Hyoides, and it gives a small branch to the eighth Pair. The other is distributed in the External Ear, Nose, Lips, and Cheeks.

Par Vagum.The eighth Pair is the Par Vagum; it rises from the sides of the Medulla Oblongata, behind the Processus Annu­laris, by several Threads which join to­gether, and go out by the same hole that the Sinus Laterales discharge themselves into the Jugulares. It is joined by a branch of the Nervus Spi­nalis, or Accessorius Willisii, and by a small branch of the Portio Dura; im­mediately after it comes out of the Skull, it gives a small branch to the Larynx, as it goes down the Neck, above the Intercostal Nerve, by the side of the Internal Carotide. At the [Page 295]Axillary Artery it casts back the recur­rent Nerves, of which the right em­braces the Axillary Artery, and the left the Aorta. These two branches ascend on each side of the Trachea Arteria to the Larynx, where they are spent on the Muscles of the Larynx and Mem­branes of the Trachea.

Then the eighth Pair after it has en­tered the Cavity of the Thorax sends out two branches, which, with the branches of the two Intercostals, form a little above the Heart, between the Aorta and the Trachea; the Plexus C [...]dincus, which gives a great num­ber of small branches to the Pericar­dium and Heart; particularly very many creep along the Aorta to the left Ventricle. The eighth Pair gives also several branches to the Lungs, which accompanying the Bronchiae, then it descends upon the Oesophagus, and is spread upon the Stomach, and some twigs go to the Concave side of the Liver, as has been said already.

With this Nerve it is usual to de­scribe another which passes out of the Skull at the same hole with it. It is called Nervus accessorius Willisii; it ari­ses from the Medulla Spinalis about the beginning of the sixth Pair of the Neck; as it ascends to the Head, it re­ceives on each side a twig from the [Page 296]first five Pair of Nerves of the Neck, as they rise from the Medulla Spinalis; then it enters the Skull, and passes out of it again with the eighth Pair, and is wholly spent upon the Musculus Trapezius.

The ninth Pair.The ninth Pair rises from the Pro­cessus Olivares of the Medulla Oblon­gata; it passes out of the Skull by its own proper hole in the Os Occipitis; as it passes to the Tongue, it gives some branches to the Muscles of the Os Hy­oides, but its Trunk is distributed in the body of the Tongue, and its Extre­mities form the Papillae Rotunde of the Tongue.

The tenth Pair.The tenth Pair rises by several small threads from the beginning of the Me­dulla Spinalis, then ascending a little, it goes out at the same hole of the Dura Mater at which the Vertebral Artery enters, passing between the Pro­tuberance of the Occiput and the first Vertebra, in the Sinus which we have observed in this Vertebra: Then it gives a branch to the first Pair of the Neck which goes to the Plexus Cervicalis; it gives another to the second Pair, and a third to the Intercostal Nerve, and then it is all spent on the oblique Muscles of the Head.

SECT. III. Of the Nerves which come out between the Vertebrae.

THE Nerves which come out be­tween the Vertebrae are thirty Pair, they arise from the Spinalis Medulla, which (as we have said before) is a continuation of the Substantia Medul­laris or Medulla Oblongata of the Brain, contained in the great holes of the Vertebrae. Its Internal Substance is mix­ed in several places, with a Substance like the cortical Substance of the Brain, as Malpighius has observed. From the first Vertebra of the Neck to the first of the Loins, it is divided by the Pia Mater into the right and left side, not quite thorow its middle, but the depth of a line or two in its fore and hind Part. From the first of the Loins to its Extremity, it is divided into a great number of Fibres which separate from one another, if they be shaken in warm Water; this Part, because of its re­semblance, is called Cauda Equina. 'Tis covered by four Membranes, of which the first is that which lines the great holes of the Vertebrae. The second is the Dura Mater, which has two Si­nus's, one on each side of the Medulla; they reach from the Occiput to the last [Page 298]of the Os Sacrum. The third is the Pia Mater; and the fourth, called A­rachnoides, is a very fine Membrane, which contains only the bundles of Fi­bres which make the Vertebral Nerves.

All the Nerves, as they rise out of the Medulla Spinalis are by the Pia Mater, divided into two Plans, which lie one above the other. And as soon as the Nerves are come out of the Ver­tebrae, they send a branch to one another, where they make a little Ganglio.

The Nerves of the Vertebrae are thirty Pair, seven of the Neck, twelve of the Back, five of the Loins, and six of the Os Sacrum; they come out at the holes in the sides of the Bodies of the Verte­brae, which have been taken notice of in the Osteology.

Of the Nerves of the Neck.The first Pair of the Neck is spread in the Muscles of the Head and Neck; it joins a branch of the tenth Pair, which goes to the Plexus Cervicalis, and it gives another branch to the In­tercostal Pair below the Plexus.

The second Pair of the Neck gives also Nerves to the Muscles of the Head and Neck, to the External Ear and Skin of the Face.

The third gives some branches to the Neck and Head; it sends out the Ner­vus Diaphragmaticus, being joined by a branch from the fourth Pair. This [Page 299]Nerve goes straight down the Cavity of the Thorax, and is spread on the Midriff.

The fourth, fifth, sixth and seventh, gives some branches to the Muscles of the Neck and Head, but their greatest branches, together with a branch of the first of the Back, enter the Arms. As soon as they enter they join all to­gether, and then they immediately di­vide into five branches. The first and innermost goes all to the Skin which covers the inner and fore part of the Arm. The second goes down by the inner Protuberance of the Humerus, by the benders of the Fingers; and in the Palm of the Hand it divides into five branches, of which one goes to each side of the little and the ring Finger, and the fifth to the External side of the middle Finger. The third accom­panies the Artery between the Sub [...]imis and the Profundus, and divides also in­to five tranches, of which one goes to each side of the Thumb and fore Fin­ger, and the fifth to the Internal side of the middle Finger. The fourth pas­ses under the Biceps to the outer side of the Arm and Back of the Hand, to be distributed into the Fingers as the foregoing. The fifth is spent on the Mulcles on the inside of the Arm. All these Nerves, except the first, [Page 300]give branches to the Muscles as they pass by.

Of the Nerves of the Back.The first Pair of the twelve Pair of the Back gives a branch (as is said) to the Arms. The twelfth Pair is dis­persed in the Muscles of the lower Belly, and all the rest run along the Sinus in the under side of each Rib, giving Nerves to all the Muscles that lie upon the Ribs and Vertebrae.

Of the Nerves of the Loins.The first and second Pair of the Loins give Nerves to the Muscles of the lower Belly, to the Inguen, to the Yard, and to the Parts contained in the Ba­sin. The third and fourth give some branches to these same Parts, but their Trunks join and make the Nervus An­terior Femuris, which is dispersed in the forepart of the Thigh. This Nerve sends a branch thorow the hole in the Ischium, which is spent in the Tricep [...]. The last of the Loins with a branch of the fourth, enter the Thigh.

Of the Nerves of the Os Sa­crum.The Nerves of the Os Sacrum come not out at the holes on its backside, but at those in its foreside; and the last comes out between the Extremity of the Sacrum and the Os Cocygis.

The first four Pair of the Os Sacrum give some twigs to the Parts in the Basin, but their great branches, with the last, and a branch of the fourth of the Loins, make the Nervus Sciati­cus, [Page 301]which is the greatest Nerve in the whole Body. As this Nerve passes be­tween the Gracilis Posterior and the Semimembranosus it gives a branch to the Skin. When it comes to the Ham it divides in two, of which one goes along the Perone to the upper Part of the Foot, and gives a branch to both sides of each Toe. The other passes under the Gemelli by the inner Ankle, and is distributed in like manner to the Toes in their under sides.

The fifth and sixth of the Os Sacrum, are very small, they are dispersed in the Sphincter, and Bladder, and Natural Parts.

SECT. IV. Of the Veins in General.

THE Ancients thought that the Veins had only one Coat; but Willis hath remarked, that the Vena Cava and the Vena Pulmonaria have four different Coats, which apparently they have thorow all their Ramifi­cations.

The first of these Coats is woven of nervous. Fibres disposed length-ways, but not altogether in a straight Line. This Coat is loose and stretches very easily, 'tis not closely tied to the rest.

The second is a Web of small Vessels in form of a Net, it furnishes the ne­cessary Nourishment to the rest of the Coats.

The third is made of little Glands, which separate the serosity of the Blood brought by the Vessels of the second Coat.

The fourth is composed of Muscular and Spiral Fibres, whose Parts succes­sively contracting, hasten the Circula­tion of the Blood.

The only reason why the Veins do not beat as the Arteries do, is because the Blood in the Veins runs from a narrow Channel into a broader; where­as in the Arteries it runs from a wide Vessel to a narrower one.

Authors do not agree about the Ori­gination of the Veins. Some say that it is in the Heart, and some others will have them to rise out of the Liver. Others think that they come from all the Parts of the Body, by their little branches which are distributed thorow it, where they say they have their be­ginning, as so many roots which join to make a Trunk, or as little Brooks that produce a River. But they have juster thoughts who think that they have no Origination at all, no more than all the other Parts of the Body, which are all formed in the Cicatri [...]l [...] [Page 303]of the Egg, where they only grow and are insensibly disclosed.

The branches of the Veins in propor­tion as they recede from their Trunks, they divide into an infinity of little Capillary branches, which at last are imperceptible. These Capillary bran­ches are, spread thorow all the Viscera, in the Membranes, and thorow all the Fibres of the Muscles, to receive the Blood which was brought there by the Arteries. The Extremities of the Veins unite to all the Extremities of the Arteries: But because there are more Capillary Veins than Arteries, the Veins unite with one another, and so likewise do the Arteries, that if one Branch be stopt, the Blood may have a Passage by another. These Unions Au­thors call Anastomosis.

The Veins have in their Cavities lit­tle Membranes or Valves, disposed at certain distances in such a manner that they open towards the Heart, and they shut towards the Extremities of the Body to hinder the Blood to return, and to sustain it, that by its weight it fall not back again. There are more Valves in the Veins of the Thighs, Legs, Feet, and of the Arms and Hands, than in the other Parts of the Body. There are none in the Vena Porta, the Emulgent Veins, nor in the Vena Pul­monaria. [Page 304]The openings of the Valves are disposed alternatively, to the end that the Blood which escapes or falls back from one may be stopt by the next. Their Figure is almost like a Half-Moon; their Substance is mem­branous, fine and strong; their number is uncertain.

The use of the Veins is to bring the Blood back again to the Heart from all the Parts of the Body.

SECT. V. Of the Vena Porta.

ALL the Veins rise from two prin­cipal Trunks, viz. The Porta and the Cava, except that of the Lungs which is a particular Vein, and sepa­rate from the rest.

The Vena Porta was so called by the Ancients, because they thought that it brought the Chyle by its Meseraick branches from the Intestines to the Liver, thorow whose Substance 'tis spread, as is said in the Section of the Liver. It rises out of the Liver; it sends out two small Veins to the Vesica Fellis called Cysticae Gemellae, one to the Stomach called Gastrica Dextra, then advancing a little to the left, its trunk divides into two branches, of which [Page 305]the least called Ramus Splenicus, goes to the left Hypochondrium: And the greatest called Mesenterica goes to the right. The Ramus Splenicus so called, because it carries the Blood from the Spleen, sends out from its Trunk two branches called Gastrica Minor & Ma­ [...], which are spread thorow all the Stomach. A branch of the Gastrica Major makes the Coronariae Stomachicae at the upper Orifice of the Stomach. It gives three branches more, two to the Omentum and Colon, and the third to the Pancreas.

Then the Splenicus divides into two branches; the one Superior, the other Inferior.

The Superior sends out the Vas Breve, and some other branches which go to the Spleen.

The Inferior gives two branches, viz. The Epiplois Sinistra, which is spread thorow the back Part of the Omentum, and that Part of the Colon which is under the Stomach. The other branch is the Gastro-Epiplois Sinistra, which is also spread upon the Omentum and upon the Stomach; it makes sometimes the Vena Haemorrhoidalis Interna. The rest of this Inferior branch enters the Sub­stance of the Spleen.

The right branch of the Porta called Vena Mesenterica, before it divides, sends [Page 306]out the Gastr [...]-Epiplois Dextra, which is spread in the Omentum and lower Part of the Stomach; it sends out al­so the Intestinalis, which goes to the Duodenum, and to the Jejunum; it gives some branches to the Omentum and Pancreas.

Then the Mesenterica divides into three great branches, which run be­twixt the Duplicature of the Mesente­rium, two of them go towards the right side which divide into fourteen branches, and these are again divided into an infinity of others less which are called Meseraicae; they creep upon the Jejunum, Ilium, Caecum, and Part of the Colon.

The last and third branch of the Vena Mesenterica, is spread thorow the middle of the Mesenterium, to that Part of the Colon which is on the left side, to the Rectum, down to the Anus, where it forms the Haemorrhoi­dales Internae.

The Use of this Vein is to bring back to the Liver the Blood which was brought by the Arteries to these several Parts.

SECT. VI. Of the Trunk of the Cava Ascendens.

ALL the little Capillary branches of the Vena Cava, which are spread thorow the Substance of the Liver, unite by little and little into others, which grow bigger; and as they ap­proach the Convex side of the Liver, where they join all together and make up one large Trunk which comes out of the Liver and divides into two great big branches, one of which goes to­wards the Heart, and forms the Trunk called Ascendens; the other goes down­wards, and is called Descendens. Both the one and the other lie upon the Body of the Vertebrae, on the right side of the Porta.

The Vena Cava Ascendens goes to the Claviculae before it divides, but as it ascends to them, it casts out three branches on each side. The Phrenica or Diaphragmatica, the Coronaria, and the Intercostalis Superior. Besides these three, it sends out the [...], or Vena fine Pari on the right side only.

The Phrenica comes from the Cava, where it pierces the Diaphragma upon which it is spread. It casts some bran­ches to the Pericardium and Mediasti­num. Some Authors think, that 'tis [Page 308]by this Vein that the Pus of an Em­piema, is carried to the Kidneys and Bladder.

Before the Cava enters the Heart, it gives the Coronaria. There are some­times two Veins of that Name; they surround the basis of the Heart.

The same Trunk as it comes out of the Heart pierces again the Pericardi­um, and passes between the two Lobes of the Lungs, sends out the [...] or Sine Pari from its right and backside, about the fourth and fifth Vertebra of the Back, it descends the Cavity of the Breast a little towards the right, till about the eighth or ninth Vertebra, where it casts out branches on each side of its Trunk called Intercosta­les, because they run along the eight last Ribs, and they join by Anastemosis with the branches of the Thoracica In­ferior, and with the Intercostal Arte­ries. Then it divides into two bran­ches; the one goes to the right, the other to the left, and they both open into the Cava above, and sometimes into the Emulgents, by which Com­munication some explain the way, tho contrary to the Laws of the Cir­culation of the Blood, how the matter of an Empiema is evacuated by Urine. This Vein gives some little branches to the Medulla Spinalis.

The Intereostalis Superior, which comes from the Cava Ascendens, is distributed in the Interstices of the four first Ribs, to which the Azygos comes not. Remark that the branches both of the one and the other run in the Sinus's which are on the lower sides of the Ribs.

Sanmichellius hath observed, that the Trunk of the Cava Ascendens gives a branch called Pneumonica; 'tis this branch which accompanies the Arteria Bronchialis of M. Ruysch.

SECT. VII. Of the Venae Subclaviae, Jugulares, and their Branches.

THE Trunk of the Cava Ascendens, as soon as it comes to the Clavi­culae, where it is sustained by the Thy­mus, is divided into two branches, the one goes to the right, the other to the left; they are called Subclaviae, which fend out several other branches.

The first is the Mammaria, which comes sometimes from the Cava, before it divides into the Subclaviae, this Vein is distributed in the Dugs, and fre­quently it goes lower, and makes an Anastomosis with some branches of the Epigastrica.

The second is the Mediastina, which is ordinarily one coming from the trunk of the Cava, it goes to the Mediat [...] ­num and Thymus.

The third is the Cervicalis or Verie­bralis, which goes up the Vertebra of the Neck, and casts some branches by the by to the Medulla Spinalis.

The Fourth is the Muscula Inferior, which comes sometimes from the Jugu­lars, 'tis distributed throw the Infe­rior Muscles of the Neck, and the Su­perior of the Breast. The branch that answers this, is called Muscula Poste­rior, because 'tis distributed in the Mus­cles which are in the hind Part of the Neck.

After that the Rami Subclavii are come out of the Cavity of the Breast, they are called Axillares, they send out the Scapularis Internus and Exter­nus which go to the Muscles of the Scapula, and to the Glands in the Arm­pits: Then they are divided into two branches; the Superior is called Cepha­lica, and the Inferior Basilica.

From the Basilica rises the Thoracica Superior, which goes to the Dugs and Muscles of the Breast. The Thoracica Inferior, which spreads it self upon the side of the Breast, by several branches which communicate by Anastomosis, with the branches of the Azygos, under the Muscles of the Breast.

The Subclavii send out also the Jugu­lares externi & interni, which go to the Head.

The Jugulares externi ascend towards the Ears, where they divide in two branches, the one Internal, the other External. The Internal goes to the Muscles of the Mouth and of the Os Hy [...]ides. The External lying upon the Parotides, divide into two branches, of which one is spread thorow all the Face, and the branches of the one side unites with those on the other side, and form the Vena Frontis, which they open sometimes in Diseases of the Head: The other branch goes to the Temples and hind Head.

The Jugulares interni afcend to the Basis of the Cranium, where they are divided into two branches, of which the greatest open into the Sinus Late­rales of the Dura Mater, by the holes thorow which the eighth Pair of Nerves come out; the least goes to the Pia Mater, by the hole which is nigh the Cella Tureica.

SECT. VIII. Of the Veins of the Arms and Hands.

THE Basilica and Cephalica, are the two principal Veins of the Arms and Hands.

The Cephalica creeps along the Arm, between the Skin and the Muscles; it divides into two branches.

The External branch goes down to the Wrist, where it joins the Basilica, and turns up to the Back of the Hand where it gives a branch which makes the Salvitella, between the ring Finger and the little Finger. The ancient [...] used to open this Vein in Diseases of the Head, in continued and intermit­ting Fevers; but the Moderns approve, not of this particular Practice; since the Knowledge of the Circulation on the Blood, there is no difference whe­ther one be blooded in the Cephalica, Mediana, or Basilica.

The Internal branch of the Cepha­lica, together with a branch of the Basilica, makes the Mediana.

The Basilica, which is the Inferior branch of the Axillaris, divides into three branches under the Tendon of the Musculus Pectoralis.

The first branch accompanies the fourth branch of Nerves that goes to the Arm.

The second is called Profundus; it reaches below the Elbow, where it di­vides into two branches; The one Ex­ternal, which goes to the Thumb, the Fore-finger, and to the Musculi Ex­tensores Carpi, The other Internal, which [Page 313]goes to the middle Finger, to the ring Finger, to the little Finger, and to the inner Muscles of the Hand.

The third branch is called Subcuta­neus, towards the inner Condile of the Arm, it divides into the Ramus Ante­rior and Posterior. The first goes un­der the Muscles of the Ʋlna to the little Finger, where it joins a branch of the Cephalica; the second near to the Elbow, sends out a branch which goes to the Wrist, then it unites with the Cephalica Interior, and forms the Mediana.

The Mediana, which is made of the Cephalica Interior, and the second branch of the Ramus Subcutaneus of the Basi­lica, divides into two branches upon the Radius, the one External called Cephalica Pollicis, which runs between the Thumb and the fore Finger. The other Internal, which goes between the ring Finger and the middle Finger, and sometimes between this last and the fore Finger.

SECT. IX. Of the Trunk of the Cava Descendens.

THE Trunk of the Cava Descendens accompanies the great Artery from the Liver to the fourth Vertebra of the Loins, where it divides into two great [Page 314]branches called Iliaci, but before this Division, it casts forth four branches from each side.

The first is the Vena Adiposa or Re­nalis, which is spread on the Coat and Fat that covers the Reins.

The second is the Vena Emulgens, which goes to the Kidney, where it di­vides into several more branches.

The third is the Vena Spermatica, of which we have already spoken.

The fourth is the Vena Lumbaris, which is not always one, but often two or three on each side, which they divide into Superior and Inferior they are bestowed on the Muscles of the Loins and on the Peritonaeum. They sometimes call the last branch of the Lumbaris, Muscula Superior.

There are some Anatomists that have observed, that there is a branch of the Lumbaris that enters the Cavity of the Vertebrae, and which ascends to the Brain, which gave them occasion to think against all probability that the seed de­scended by that Vein from the Brain.

A little below the Emulgents the great Artery goes above the Cava, and then the Cava divides into two bran­ches called Iliaci, because they pass a­bove the Ilia to go to the Thighs. Near this Division they send out one or two branches called Venae Sacrae; they [Page 315]go to the Medulla of the Os Sacrum.

Then the Venae Iliacae divide into two branches, the one Internal, the other External. The Internal sends out two branches, the Muscula Media which is spread thorow the Muscles of the Thigh, the Hypogastrica, which is some­times double, it's spread about the Sphincter of the Anus; wherefore 'tis called their Haemorrhoidalis Externa. The Hypogastrica is spread also upon the Body of the Bladder, upon the Matrix and its Neck, therefore some thought without ground that the Menstrual Blood was discharged by this Vein which comes only from the Arteries.

The External branch of the Iliacae sends out three branches, two before it goes out of the Peritonaeum, and the third after it goes out of it.

The first is the Vena Epigastrica, which comes rarely from the Cruralis, it goes to the Peritonaeum, ascends to the Musculi Recti, where it Rencon­tres the Mammariae, with which it communicates by Anastomosis.

The second is the Vena Pudenda, 'tis spread upon the Parts of Generation.

The third is the Muscula Inferior, it goes towards the Articulation of the Remur, and is distributed to the Mus­cles of this Part.

The Iliaca Exterior, after it hath sent out all these branches, takes the name Cruralis, and then sends out six bran­ches more.

The first is the Vena Saphena, which goes down under the Skin along the inside of the Thigh and Leg, accom­panied with a Nerve which loses it self at the inner Ankle. The Saphena turns towards the upper Part of the Foot, where it gives several branches, of which some go to the great Toe.

The second is the Iscias Minor, this Vein is little; 'tis spent on the Muscles and Skin which are about the upper Joint of the Femur.

The third is the Muscula Externa, because it goes to the External Muscles of the Thigh, on the other side of the Cruralis, just opposite to the begin­ning of this Vein, there goes out ano­ther called Muscula Interna, which goes to the Internal Muscles of the Thigh.

The fourth is the Poplitaea made of two different branches united together; it goes straight down by the Ham to the Heel; it lies pretty deep, upon which account it can hardly be opened. The branches which appear in this place are not of this Vein.

The fifth is the Suralis, which is pretty big, and which divides into [Page 317]two branches, the one External which is least, the other Internal which is biggest. Each of these branches divide again into two more; the one Ex­ternal, the other Internal.

The Suralis distributes its branches upon the fat of the Leg, and makes with the branches of the Poplitaea, all those Plexus of Veins which are conspi­cuous, on the upper Part of the Foot.

The sixth and last branch of the Cruralis is the Iscias major, which goes also to the Muscles and fat of the Leg, and is divided afterwards into several branches, which are distributed to the Toes.

SECT. X. Of the Lymphatick Vessels.

I Have referred the Lymphatick Vessels till now, because they do not pro­perly belong to any particular Part of the Body. They are small and Pellucide Canals, which carry a thin and clear Liquor from all the Parts of the Body towards the Heart. They have a fine transparent Coat; their Cavity is full of Valves, which open towards the Heart, and which shut towards the Ex­tremities. Of these Lymphatick Ves­els, some rise from the Viscera, as the Liver, Spleen, Lungs, &c. and others [Page 318]from the Glands, which are spread tho­row all the Parts of the Body.

They have no common Trunk nor Receptacle, but they discharge them­selves into different Vessels, as they are nearest to them, viz. the Recep­tacle of the Chyle, the Ductus Tho­racicus, and the Subclavian, Axillary, Jugular, and other great Veins.

The Lympha which the Vessels con­tain comes from the Serosity of the Blood which is separate in the Glands. Some Authors think, that it comes also from the Succus Nervosus, which is brought by the Nerves to the Glands; it's ordinarily clear and transparent, but it changes its colour according as 'tis tinctured by the Chyle, Bile, Blood, and other Humours. 'Tis insipid of it self, but sometimes 'tis acid, salt, or bitter. It coagulates sometimes by the mixture of Liquors and dissolution of Salts, as the Serosity of the Blood, and when it's dryed, it has a particu­lar Smell.

If you examine it Chymically, you may draw from it much volatile but no fixt Salt, some Phlegm, and Sulphur, and a little Earth. Acids coagulate it, and Volatile Spirits dissolve it.

The Lympha serves to liquisie the Chyle and Blood, that thereby they may the more easily move. Some think [Page 319]it serves to nourish and augment the Body: But if we consider its Nature, and the Parts it discharges it self into, 'tis more probable, that 'tis a proper Menstruum for the last and finest dis­solution of the Chyle. It hinders the dissipation of the Spirits; it helps to make Fermentations; it temperates the Acrimony of the Bile and Acids; it dissolves Salts.

The breaking of the Lymphatick Vessels, is often the cause of Dropsies.

SECT. XI. Of the Arteries in General.

WIllis hath demonstrated that the Arteries have four Coats, as well as the Veins.

The first is thin and nervous; its inner is woven of little Veins, Arte­ries, and Nerves, whose Extremities terminate in the other Coats.

The second Coat adheres to the first; in it there are an infinite number of little white Glands.

The third is musculous, made of many Spiral Fibres, which are close to one another.

The fourth and last is a Coat, whose Fibres are in a straight Line.

The Blood which is necessary for the nourishment of these Coats, is [Page 320]brought to them by the little Arteries, and that which remains, is brought back by the Veins; the Serosity is se­parated by the Glands, and the Animal Spirits are brought by the Nerves to the muscular Fibres of the Coats, for the assisting the Pulse of the Arteries.

The beating of the Arteries, as well as that of the Heart, is nothing else, but what we call Systole and Diastole. It is done, as much by the Structures of the Fibres of the Heart and Arte­ries, as by the Blood, which being thrust with Violence by the Contra­ction of the Fibres of the Heart into the Aorta, dilates its Fibres, because it is thrust from a wide passage into a narrow one, the Fibres being once di­lated, by their spring contract again, and so thrust the Blood to their Ex­tremities, as fast as they receive it from the Heart.

The Use of the Arteries is to carry the Blood to all the Parts of the Body. It is hard to distinguish the Capillary branches of the Arteries from those of the Veins, if it is not by the Injection of tinctured Liquors.

The Capillary branches throughout all the Body, unite with one another as well as with the Veins.

SECT. XII. Of the Trunk of the Aorta Ascendens.

THE Aorta coming from the left Ventricle of the Heart sends out two branches called Coronariae, before it pierces the Pericardium, but after it hath pierced it, it ascends a little, and then it crooks downwards and forms the Aorta Descendens. From the upper side of this Crook it sends out three branches, two on the left side, which are one Subclavian, and one Carotide, one on the right side which is the right Subclavian, from which imme­diately rises the right Carotide.

The Arteria Subclavia on each side send out the Mediastina, the Intercosta­lis Superior; the Mammaria, the Cer­vicalis or Vertebralis, and the Muscula which goes to the Muscles of the Neck, of the Breast, and to the Glandulae Thy­roides. After that the Subclavia hath passed thorow the Musculus Scalenus, it is called Axillaris.

The Arteriae Carotides, as they ascend on each side of the Trachea Arteria, give some small branches to the Tra­chea Arteria, to the Larynx, to the Glandula Thyroides, and then they di­vide into two branches, the one Inter­nal, the other External.

The External Carotide sends out four branches.

The first goes to the Tongue, to the Muscles of the Os Hyoides, and to the Pharynx.

The second divides into two bran­ches, of which the first loses it self in the Muscles Milohyoides and Digastrici; and the second goes along the basis of the lower Jaw, and is lost in the Mus­cles of the Lips.

The third branch of the External Carotide divides at the Angle of the lower Jaw into two branches; one en­ters into the lower Jaw, and the other makes the Arteria Temporalis.

The fourth branch of the External Carotide goes to the Muscles on the hind Part of the Neck, and to the Skin of the hind Head.

The Internal Carotide passes thorow the Canal in the Os Petrosum, gives some branches to the Dura Mater, joins with the Cervicalis, sends out branches to the Glandula Pituitaria, Plexus Cho­roides, then it runs thorow all the Cir­cumvolutions of the Cerebrum and Ce­rebellum, and loses its Capillary bran­ches in their Cortical Substance.

The Axillaris, having pierced the Scalenum, gives some little branches to the nearest Muscles; it sends out the Thoracica Superior and Inferior, the Sca­pularis, [Page 323]and then it gives a branch, which passes under the Head of the Humerus into the Musculus Longus and Brevis of the Arm.

The Trunk of the Axillaris goes down the inside of the Arm, giving branches by the way to the Muscles that lie upon the Humerus. Above the Elbow it sends out a branch, which is spread upon the Internal Condile of the Humerus.

At the bending of the Elbow this same Trunk divides into two branches, the one External, and the other In­ternal.

The External runs along the Radius, it casts out a branch which goes to the Supinator, and ascends to the Brachialis Internus, in the rest of its course down to the Wrist, it gives branches to the Longus, Rotundus, and benders of the Fingers, Wrist, and Thumb. Being come to the Wrist it sends out a branch, which goes to the beginning of the Tenar, then it passes under the Tendon of the Flexor Pollicis; it gives branches to the Exter­nal Part of the Hand, and it passes un­der the Muscles between the fore Finger and the Thumb, to which it gives a branch on each side.

The Internal branch goes down a­long the Cubitus to the Wrist, and is distributed to the middle Finger, [Page 324]to the ring Finger, and to the little Finger.

SECT. XIII. Of the Aorta Descendens.

THE Aorta Descendens sends out first the Bronchialis of M. Ruysch, which accompanies all the branches of the Bronchiae. A little lower it gives the Intercostalis Inferior the Phrenica which are distributed in the Diaphragma, the Lumbaria which goes to the Muscles of the Loins and Psoas, the Celiaca which divides into two branches, the one on the right, the other on the left, of which the first gives the Gastrica Dextra, which goes to the Stomach, the Cisticae to the Gall-Bladder, the Epiplois Dex­tra to the Omentum, the Intestinalis to the Intestine Duodenum, and to a Part of the Jejunum, the Gastro-Epiplois to the Stomach, to the Omentum, and some branches to the Liver, which enter the Capsula Communis, to accompany the branches of the Vena Porta.

The left branch of the Caeliaca gives the Gastrica Dextra, which is also spread on the Stomach, the Epiplois Sinistra to the Omentum, and the Splenica to the Substance of the Spleen.

Then the Aorta Descendens sends out the Mesenterica Superior, the Renales or Adiposae, which go to the Glandulae Re­nales, [Page 325]and fat about the Reins, the E­mulgents to the Reins; the Spermaticae to the Testicles, the Lumbares Inferiores to the Muscles of the Loins, the Mesen­terica Inferior, which with the Superior is distributed thorow all the Mesente­rium, and which accompanies all the branches of the Venae Meseraicae. When the Aorta is come to the Os Sacrum, it divides into two branches called Iliacae, and before these branches go out of the Cavity of the lower Belly to go to the Thighs, it sends out 4 or 5 branches.

The first is the Sacra, which rises near the middle of the division, and is spread in the lower Belly upon the Os Sacrum.

The second and the greatest is the Hypogastrica, 'tis distributed to the Blad­der, to the Rectum, to the outer and inner side of the Matrix, and to the Os Sacrum; then it gives two considerable branches which go out of the lower Belly. The first passes under the Pyri­formis, and is distributed to the Muscles called Glutaei. The second which is lower than the first gives also two branches pretty big, of which the first goes to the Obturatores, the second pier­ces the Cavity of the Abdomen, under the Pyriformis, and loses it self by se­veral branches in the Glutaeus Major.

The third is the Pudenda, which passes under the Os Pubis, goes to the Privi­ties; [Page 326]when this branch is wanting the Hypogastrica supplies its place.

The fourth is the Ilias Minor or Mus­cula Inferior, it goes to the Muscle Ilia­cus, transversus, and Obliquus Ascendens.

The fifth and last branch is the Epi­gastrica, which goes up under the Mus­culi Recti.

After that the Trunk of the Iliaca is come out of the lower Belly, it is called Cruralis; it sends out two or three branches, which lose themselves in the Skin and Muscles upon the upper and forepart of the Thigh.

Four or five fingers below the Groin, the Crural sends out three branches bigger than the first three.

The first is called Muscula, which gives several branches. The first passes between the Muscles called Iliacus and Pectineus, and loses it self in the third Head of the Triceps in the Semimembra­nosus or Seminervosus, in the beginning of the Biceps, in the Quadrigemini, and in the Cavity of the great Trochanter.

The 2d, 3d, and 4th. go to several parts of the Triceps & Gracilis Posterior.

Then the Trunk of the Muscula goes under the first of the Triceps, and di­vides into three branches more.

The first having pass'd the third of the Triceps, is lost in the Semimembra­nosus. The second passes under the Fe­mur [Page 327]to the Vastus Externus. The third goes a little lower, casts branches to the Tendon of the third of the Triceps, it loses it self at the end of the Semi­nervosus, and at the end of the great Head of the Biceps.

The second considerable branch of the Trunk of the Crural goes to the External Part of the Thigh; passes under the Sartorius, under the Gracilis Rectus; it casts some branches to the end of the Iliacus, to the beginning of the Gracilis Rectus, to the Vastus Externus, Cruralis, Membranosus, and forepart of the Glutaeus Minor.

The third rises almost from the same Part of the Crural, and loses it self in the middle of the Gracilis Rectus, Cru­ralis, and Vastus Externus.

The Crural having sent out these three branches, gives several branches to the Sartorius, to the Gracilis Posterior, but the greatest goes to the Vastus Externus.

As the Crural descends it sinks the deeper in the hind part of the Thigh, passing thorow the Tendons of the Tri­ceps; being come to the Ham, the first branch it sends out is spread on the hind part of the Thigh Bone, and it goes to the little Head of the Biceps; then it casts out several other branches, which lose themselves in the fat, and in the Ex­tremities of the Muscles behind the Fe­mur. [Page 328]Under the Ham it sends out two Poplitaeae, which go round the Knee, the one in the inside, the other in the out­side. It casts out a little lower several other branches, of which some go to the beginning of the Gemini, of the So­leus, Plantaris, and Poplitaeus, and the rest surround the Tibia on all sides.

Then it divides into two branches, of which the first passes thorow the Mem­brane, which joins the Tibia and Perone together, upon which it continues its way, giving branches to the Tibiaeus Ex­ternus, and to the Extensores Digitorum.

The second branch divides into two more, the one External, the other In­ternal.

The External after it hath given branches to the Soleus, to the Peronaeus Posterior, and to the Flexor Pollicis, pier­ces the Membrane between the Tibia and Perone; rises upon the External Ankle, to spread it self upon the upper part of the Foot.

The Internal as it descends gives branches to the Soleus, to the Flexores Digitorum, to the Tibiaeus Posterior, then it passes by the Cavity of the Perone, where it divides into two branches, of which one passes under the Tenar to the great Toe, the other passes between the Musculus Brevis and the Hypotenar, and is distributed into the other three Toes.