Dr. Willis's practice of physick being the whole works of that renowned and famous physician wherein most of the diseases belonging to the body of man are treated of, with excellent methods and receipts for the cure of the same : fitted to the meanest capacity by an index for the explaining of all the hard and unusual words and terms of art derived from the Greek, Latine, or other languages for the benefit of the English reader : with forty copper plates.

CHAP. XXII. The fifth, sixth, and seventh Pair of Nerves are unfolded.

OF the aforesaid four Pair of Nerves, the two former seem chiefly to serve for the Sense only, but the two latter for Motion; and every single Nerve of them destinated to a peculiar Province: but this which follows next, to wit, the fifth Conjugation of Nerves serves for the exercise of either Faculty, to wit, both of Sense and Motion; nor is its Province so strictly bounded, that it should belong only to one member, for it is distributed to the Eyes, Nose and Palate, and the rest of the parts of the Face, and besides, helps in its part in some sort the offices and actions of the Praecordia and almost of all the Viscera.

This pair (which by the Ancients was accounted the third, by us the fifth pair, and that by right of order or position) below the former nerves, proceeds with a broad and large trunk from the sides of the annular Pro•…•…uberance or Process sent out from the Cerebel. It consists of very many Fibres gathered to∣gether, some of which are soft, others hard; so that the great trunk of it near its beginning, is nothing else than a little bundle of very many nerves, some of which are bestowed on these parts, and others on other parts, and in some they perform the offices of motion, in others of sense. But that so many nerves being de∣stinated to so many several members, and remote one from another, yet arising together, are collected as it were into one bundle, the reason is, that in all the parts to which those Nerves belong, a certain Sympa∣thy and consent of actions might be conserved: to wit, the communion of those Nerves is the cause why the sight and smell move spittle and please the Palate; nor by any other means are the Praecordia affected, according to the various conceptions of the Brain, and transmit their affections to the several parts of the Face; from whence the aspect or countenance of the whole Animal is pathetically figured, as shall be shewed more particularly below.

In the mean time, let us deliver a short Hypotype or Figure of this Nerve; its trunk going out of the sides of the greater Ring, sometimes near its beginning, but oftner the Dura Mater being first perforated or passed through, is divided into two noted branches. The first of these tending straight downward, go∣ing out of the Skull at a proper hole, in its descent towards the lower Jaw, (to whose parts it is chiefly destinated) is divided into more branches, with which it furnishes the Temple-muscle, also the Muscles of the Face and Cheeks. Moreover, from them shoots and branches are distributed

into the Lips, Gums, roots of the Teeth, Jaws, Throat, the farther end of the Palate, yea and the Tongue; for this reason chiefly, that the Nerves going out of the lower branch of the fifth pair, might effect, be∣sides sense, the divers offices of Taste and Touch or Feeling, and motions of a various kind in the afore∣said members and parts; most of which, as the chewing of the aliment, also those which have respect to configuration or framing of the mouth and face in laughing or weeping (as we have already noted) are performed unknown to the Brain, that is involuntarily, and by the help of the Cerebel only, from which these Nerves are derived.

The other superior, and also the greater branch of the fifth pair under the Dura Mater nigh the side of the Turkey Chair goes straight forward for a little space, and is inlarged into some shoots over against the pituitary Glandula to the trunk of the Carotick Artery or the wonderful Net, (where it is present) then it is inoculated into the Nerve of the sixth pair, and from thence sends back sometimes one, some∣times two shoots; which being united with another shoot, turned back from the Nerve of the sixth pair, constitute the root or first trunk of the intercostal Nerve. Concerning this intercostal Nerve, which is made of the lower ramification or branching out of the Nerves of the fifth and sixth pair, it shall be spo∣ken of particularly hereafter.

Presently after the branches or shoots reflected or bent back for the root of the intercostal Nerve, that greater Nerve of the fifth pair is divided into two noted branches. The lesser and uppermost of these tending towards the globe of the Eye, and becoming again twofold, sends forth two branches from it self; one of which turning towards the inward side of the Bone, containing the ball or angle of the Eye, is divided into two shoots. The other of these having passed through the Bone nigh the mammillary Processes, is carried into the nostrils: the office of this Nerve is to keep a Sympathy and consent of action between the Nostrils and some other parts: but the other branch of this division is bestowed on the Muscle by which Brutes wink.

The second Ophthalmick branch of the fifth pair is divided into four or five shoots, all which going forward above the Muscles of the Eye, and in some part passing through its Glandula's, are almost all lost in the Eye-brows, unless that in the passage they send down two small shoots which enter the Scle∣rotick Coat a little below the Tendons of the Muscles, and reach to the Uvea, or the fourth thin Mem∣brane that cloaths the Optick Nerve; yea and also send in the passage small shoots to the Glandula's of the Eye. It seems that these Nerves of the fifth pair, being distributed into the Glandula's of the Eyes and Eye-brows, serve chiefly to the involuntary and pathetick actions of those parts; the chief of which are, the languishing and mournful aspect of the Eyes in weeping, and the unwilling pouring out of tears. For as the lower branching of the fifth pair, to wit, the intercostal nerve, provideth in man for the Praecordia, it easily happens, that from the sad affection of these, the Cardiack branches of this Nerve being forced and wrinkled into Convulsions, the aforesaid Ophthalmick branches also so correspond, and by wrinkling the Eye-brows, and by compressing the Glandula's, produce those kind of looks of the Eyes, and marks of sorrow and grief. Further it is observed, that from the Ophthalmick branch of the fifth pair a certain shoot is sent back higher nigh the heads of the Muscles; which when it has passed through at a proper hole, the Bone containing the ball of the Eye, is carried straight into the caverns of the Nostrils. Hence, as I think, a reason may be given, wherefore passing out of a dark place into the light, at the first beholding of the Sun, presently whether we will or no we shall sneez; to wit, the eyes being too strong∣ly struck by the object, and being suddenly and disorderly moved, that they might turn themselves aside, the same affection is immediately communicated through the aforesaid Nerve to the Membrane covering the hol∣low caverns of the Nostrils, which being thence contracted and wrinkled, (as it is wont by some sharp thing pulling it) provokes sneezing.

The second or greater branch of the second division of the Nerve of the fifth pair being carried nigh the ball of the Eye, is again divided into two branches. The lower of these being bent downwards, cleaving into many shoots, is bestowed on the Palate and upper Region of the Jaws: The other and higher branch of this second division stretching beyond the ball of the Eye, passes through, together with the Vein and Artery, a proper hole made in the bone of the upper Jaw; which Vessels this Nerve climbs and variously compasses about with many shoots sent forth; then arising out of the bone, it imparts little branches to the Muscles of the Cheeks, Lips, Nose, and to the roots of the upper Teeth. Therefore forasmuch as this Nerve embraces and binds about the sanguiferous Vessels destinated to the Cheeks and the other parts of the Face; from hence a reason may be given, why the face is covered with blushing by shame: for the ani∣mal Spirits being disturbed by the imagination of an unseemly thing, by and by endeavouring as it were to hide the face, their irregularities enter this Nerve, so that the shoots of the same Nerve, embracing the blood-carrying Vessels, by compressing and pulling the same, cause the blood to be more forced into the Cheeks and Face, and the Veins being bound hard to be there for some time staid and detained. But for∣asmuch as many shoots and fibres of the same maxillar Nerve, derived from the fifth pair, interweave themselves with the flesh and skin of the Lips, hence the reason is plain, why these parts are so very sen∣sible, and besides, why the mutual kisses of Lovers, impressed on the Lips, so easily irritate love and lust by affecting both the Praecordia and Genitals; to wit, because the lower branching of the same fifth pair actuates these parts constituted in the middle and lower Belly, and draws them into the like affection with the Lips. The same reason holds of Love presently admitted by the eyes, that as the Poet says,

Mars videt hanc, visam{que} cupit. As soon as Mars saw her, he desir'd her.

We have but now intimated, that many shoots os this Nerve were destinated for the business of chew∣ing; and therefore, because the aliments to be taken ought to undergo not only the examination of the taste, but also of the smell and sight, from the same Nerve, whose branches being sent to the Palate and Jaws, perform the business of chewing, other shoots, as it were fore-runners, are carried to the Nostrils and Eyes, to wit, that these Organs of the other Senses might be furnished with some helps of proba∣tion also, for the better knowing or distinguishing the objects of taste. Certainly from the nearness of kindred and manifold affinity of this Nerve, being also much diffused in the Head, the mutual de∣pendencies and confederations of very many of its parts, proceed. But how this Nerve in other Pro∣vinces, to wit, in the Thorax and lower belly, and there about the motions and sensions of the Prae∣cordia and Viscera, doth cause various Sympathies of them among themselves and with other parts, shall afterwards be more largely shewn, when we shall speak particularly of the intercostal Nerve, which is rooted in this Nerve of the fifth pair; where, from the manifold communication of this Nerve, may be easily drawn the reasons of sneezing, yawning, laughing, crying, and of other acti∣ons merely natural. In the mean time, the superior branching of the Nerve of the fifth pair shews it self after this manner in the Head, and almost after the same manner is divaricated in most liv∣ing Creatures; except however, that in some presently after its rise, it is divided into three great branches; one of which is destinated to the lower Jaw, the other to the Eye and Nose, and the third to the Cheek.

The Nerve of the sixth Conjugation follows, which arising out of the lowest foot of the annular Protuberance, and being hid under the Dura Mater: presently goes out of the Skull at the same hole with the nerves of the third and fourth pair, and is carried with a single Trunk into the ball of the Eye; but so, that near the side of the Turkey Chair it is inoculated with the second branch, or the greater of the fifth pair; from whence it turns back, sometimes one little branch, sometimes two; which being united with the branches of the fifth pair running back, constitute the beginning of the intercostal nerve. Then this nerve going forwards, is divided into two branches near the ball of the Eye; one of which is inserted into the Muscle drawing back the Eye planted in its outward angle; and the other being torn into various fibres, is bestowed on the seventh Muscle pro∣per to Brutes; so that this nerve also seems to serve to those motions of the Eye that are almost on∣ly pathetick, or excited by natural Instinct. For, as to the use of the former shoot, it plainly ap∣pears, that it is innate to every Animal in a sudden fear to draw the eyes backward, and to look for what is to be feared on either side and behind: then as to its other shoot, whereby Brutes winke or twinkle the eye, it is obvious that this same motion is sudden and extemporary, without any previous intention, whereby the eye endeavours to shun the injuries of outward things that occur.

The seventh Conjugation of Nerves, accounted for the fifth by the Ancients, is imployed about the sense of hearing. Of this pair commonly are noted two Processes, the one soft, the other hard; which indeed seem to be two distinct nerves, for that although they have their beginnings nigh one another, yet are somewhat distinct, and are carried to divers Organs; in the mean time either agree∣ing in a certain common respect of use or action. For whilst one Nerve performs the act of hearing, the other supplies some requisites whereby that act may be the better performed: wherefore we shall not much strive against the common description of this pair, by which it is taken for one. The process of this pair, or the auditory Nerve properly, which is called the soft Branch, seems to arise in man out of the lower side of the ringy Protuberance, and in beasts out of the midst of the lesser Ring. In some Diffections I plainly found, that this softer Nerve, having its beginning lower, seem∣ed to ascend a little before it went out of the medullar stock; and the other more hard Nerve seem∣ing to arise higher (viz. out of the medullar whitish line leading about the bottom of the fourth Ventricle) did descend a little, and arose near the meeting with the other. This softer Nerve is car∣ried into the passage of the stony Bone, where entring into the den destinated for the receiving the sound, which is on this side the Snail-like winding and the Drum, it so infolds it self into the most thin Membrane wherewith that den is covered, that as often as the Air implanted in that cavern is moved by the stroke of the external Air made upon the Drum, this impression striking this Membrane, and stir∣ring up as it were an undulation of the animal Spirits, is forthwith carried towards the common Senso∣ry by the passage of the Nerve there implanted. There will be a more opportune place of discoursing, after what manner, and by what sort of Organs Hearing is performed, when we shall speak of the Sen∣ses.

The other Nerve of this pair, or the more hard process, which conduces rather to motion than sense, passing through the stony Bone at an hole proper to it self, arises near the auditory passage, where it pre∣sently receives into its trunk a branch from the wandring pair brought thither; then immediately after that joyning together or coalition, it is divided into two branches: The first of these tending down∣wards, is bestowed upon the Muscles of the Tongue and the Bone Hyoides; the other going about the au∣ditory passage, and bending more upwards, is divided into three shoots; the first of which, answering to the Nerve of the former division, bestows some shoots on the Muscles of the Lips, Mouth, Face, and Nostrils, and so actuates some exterior Organs for the forming the voice, as the former doth some inte∣rior Organs. The second shoot of this division distributes its shoots into the Muscles of the Eyebrows

and Forehead; and the third into the Muscles of the Ear it self. The offices and uses of all these have been already shewn, the summ of which is, that as often as the sound is admitted in, especially if it be any ways unusual, new, or to be wondred at, presently by a certain natural instinct the Ears and Eyes erect and open themselves: to wit, for that end shoots from this Nerve are inserted into the Muscles of the Eye-lids and Ears, that by the passage of these, the Spirits inhabiting either Region, might be call∣ed out as it were to watch. For a like reason shoots from the same hard process of this Nerve are di∣stributed both into the Muscles of the Tongue and of the Bone Hyoides: as also into those of the Lips and the outward parts of the Mouth, that by their passage, the sound being transmitted further to these Organs of the voice, it being equal or like the same, might officiously answer it as it were an Echo. That the descriptions of the aforesaid Nerves might be better understood, I have thought good here to represent in the following Figure the branchings of the fifth and sixth pair. The seventh pair is fitly deli∣neated in the ninth Figure.

This Figure shews the Branchings of the fifth and fixth pair of Nerves.

• A. The Nerve of the sixth pair (which we place first, because it is outmost in the Scheme) from whose trunk two shoots a. a. are carried into the two Muscles of the Eye.
• A. A shoot from the Nerve of the sixth pair bent back for the root of the intercostal Nerve.
• B. The trunk of the fifth pair being presently divided into two great branches.
• bb. Two shoots from this branch bent back for the root of the intercostal Nerve.
• C. The division of the upper part of the trunk into four lesser branches, the uppermost of which c. being the Ophthalmick or belonging to the Eye, and entring the orb of the Eye, sends forth four shoots.
• c. The first being carried nigh to the ball of the Eye, is bent back into the Nostrils.
• d. The second passing by the outward orb of the Eye, is carried into the Muscles of the Forehead.
• ee. The third and fourth are distributed into the Eye-lids and interior Glandula's of the Eye.
• D. The second branch of the second division is also Ophthalmick, which entring the ball of the Eye, and carried towards the outward corner of the Eye, is distributed into the Eye-lids and outward Kernels.
• E. The third branch of the second division, or the maxillar, which passing by the orb of the Eye, enters and hole proper to the bone of the Jaw, in which passage it sends forth a shoot e. through another hole into the chew∣ing Muscle, then arising up, it is carried out at the hole.
• f. A shoot into the Muscles of the Nose.
• ggg. It sends fortb many shoots into the upper Lip.
• F. The lower branch or the fourth of the second division, which descending right towards the hollowness of the Mouth, is divided into two branches.
• h. The first is distributed into the Gums.
• i. The second is bestowed with many shoots upon the Palate.
• G. The second branch of the first division of the fifth pair, which tending straight downwards towards the lower Jaw, sends forth in its passage many shoots.
• k. A shoot of it into the Parotid Glandula's, or those near the Jaws.
• l. A shoot to the inward Mandible.
• m. A shoot which compassing about the process of the lower Jaws, is carried to the outward part of the exte∣rior Masticator.
• n. Another shoot tending opposite to the former, having compassed the same process is distributed into the inward part of the same Masticator.
• H. The trunk of the same greater branch carried further, is cleft into many shoots, of which
• o. Tends into the root of the Tongue.
• pp. Is carried with many shoots into the substance of the whole Tongue.
• q. Into the parts under the Tongue.
• r. Passing through the bone of the Jaw, is divided into many shoots which are dispersed, partly into the lower Lip s. s. s. and partly into the Chin t. t. t.

[illustration]

Fig. I.

[illustration]

Fig. II.

KK. p. 118

The Second Figure shews all the Nerves, which being carried from the Nerves of the third, fourth, fifth, and sixth Pair, are bestowed upon the Muscles and other parts of the Eye.

• A. The Nerve of the third pair carried to the three straight Muscles, and into the outward oblique one.
• B. The Nerve of the fifth pair, or the pathetick Nerve, goes whole into the trochlear Muscle.
• C. The Nerve of the sixth pair into the drawing back Muscle, and the seventh proper to Beasts.
• D. The Nerve of the fifth pair whose Ophthalmick branch E. is divided into two branches,
• F. The upper branch, being presently torn into manyshoots, tends directly towards the inner corner, where it is bestowed on the Glandula's and Eye-lids.
• G. The lower Ophthalmick branch, which being divided into shoots, respects after a like manner the Glandula's and Eye-lids towards the outward corner of the Eye;
• a. The Nerve of the fourth pair for the trochlear Muscle.
• b. A branch of the Nerve of the third pair for the Muscle lifting up the Eye-lids.
• c. A branch of the same pair for the Muscle shutting the Eye-lids.
• d. A branch of the same Nerve for the Muscle pressing close the Eye-lid.
• f. A branch of the same for the outward oblique Muscle.
• g. Lesser Nerves out of the infolding of the third pair, tending through the Sclerotick Coat into the Uvea.
• e. The Nerve of the sixth pair for the drawing-back Muscle.
• *** Fibres or lesser branches from the fifth and sixth pair for the seventh Muscle, proper to Brutes.
• h. A Nerve coming from the upper Ophthalmick branch into the Nostrils.
• i. A Nerve from the same branch into the Eye-brows and Fore-head.
• H. The trunk of the fifth pair cut off, which tends to the lower Jaw.
• I. A branch of the same cut off, which is carried to the Palate.
• K. Its upper maxillar branch.