Book 8

| NSAI A ETO A IIE
| 408 Boox 8 Of the Body of Man, and its Funttions. Chap. 2:
is raifed up, butbeing loofened itis dilated, and depreffed in Infpiration or drawing in of the Air, or fecching wind, And becaufe through the Diapbragma, neat che Back, the Gullec, che Arteria magna, and VenaCava do pats, left by the perpecual motion of the Diapbragma thele parcs fhould be ftraicened and agitated, che middle of the Dia-
of che Diaphragme or Midrif is moved, yet chat part may not be contracted. Having done with the Vital Function, it follows inthe nexc place, chat weenquire by
i med. . And in che firft place, thacthe Inftrument of feeling which is che moft common fenfe Ri} _ The Skin isa Membrane,hath been faid already in Book 7. Chap.6, Buc asco the Skin,’cts true indeed Ae | is mot the plat ic is folded about the who} Body, nor only that may cloath the whol Body, andde- 3 eae fend the other parts from external injuries, and that it may faften and bind al the pacts toge- PO of feeling. Cher but alfo chac ic may be the Inftrument of feeling, and may perceive excernal objects r ie nN ‘and injuries every Way incident. And Galen tightly {aid 1. de temper. cap.9. that the i) Skin, e{pecially thac inthe hand, isthe Rule of al fenfible objects, and an Inftrument of | | feeling properly fitred for fo prudent a Creature as Man 1s. Yer neverthelefs in chac the ab Skin feels, it does ic becaute ic is Membranous, or receives fibres and little Nervous Mem- branes from the parts beneath ir. The parts. The Tongue isthe Inftrument of Tafting, whofe flefh is {fpungy, rare and loofe, covered “099 nfe of by a moft thia Membrane, common to che Mouth and Pallac, into which che Nerves of che the tongue +564 and fourth Conjugation are expanded. _ Now the Tongue hath chree pair of Nerves; che former two are diffeminated through the Coat thereof, and ferve che Tafting Faculty : che chicd is {pred inco che Mufcles of the Tongue for to move the fame. That the Organs of the Smel are the Mammillary Proceffes, was faid before in Book 7. chap. 4. The Organ The adequate Organ of che Hearing is indeed the whol Ear. But what is thechief parc of Hea- in che Ear chat contributes to Hearing, Auchors are at great variance, while fome fay the ta ae qimplanced Air, others a certain Nerve is che immediate Inftrumenc of Hearing. Butifwe : ™ Mhal diligently weigh the matrer, thefe Opinions may be {ome waies reconciled, as was faid
fe» ae ae the im- Lib.7. cap.3. For itis alcogether probable that a certain implanted Air of aery fubftance is
Sighc is fhining and lightfom; fo alfa to receive founds, ’cis credible chac che Organ of Hea= ring is Aerial, Buc feeing the Organ of a Senfe ought co be a part fimilac and abimated, fimple Air cannot be the Organ of Hearing 5 but ic muft be a certain Aery fubftance, bred of che moft pure and Aery parc of the Seed and maternal blood, fuch as may have affinity with che external Air, and may receive the founds hroughc in. But whether chis ingrafced Air be inthe exparded Nerve, or in fome Cavity, can hardly be determined; fince Anatomy in chis poine affords liccle help, and after death we find notching obvious to the fight. Whence alfo ic ig that thar fame other Queftion can hardly be refolved 5 Whecher. this Air be only an internal Medium, co receive and cranfmic founds co che true Organ of Hearing, which is the widened end of the Auditory Nerve? or, Whether (which is the Opinion of Capivaccivs) chis Air it felf feaced in the expanded Nerve be che Organ of Hearing?
the ex- All the other parts of the Ear have each theirufe in Hearing. ‘The external Ears by
Hence chofe that are crop-eared, or have their Barlaps cut off, they do not hear exa ly, bue
perceive founds like fluctuacing Water.
From the outward Ear or Earlap, the found comes firft into the Auditory hole, which is sory paf- boney and covered witb achin Skin compact and {moorh, and which fticks exceeding faft co | fage or he bone, fit co receive founds. Acthe end of this bole or paflage_is a Membrane which they Bee fale: cal the Drum, made to this end, That the external Air might not flip intothe Cavity of che
che Dram. Ear, and fo difturb che Hearing.
tBe andi-
of Mufick teach us, that che drieft chings are moft apt co found. the three Namancaneafily cel che ufe of che reft of the parts of the Ear, viz. The Cavities, the lieile bones phree litcle bones called the Mallec, che Anvil, the fticrup 5 fince we have no fuch helps bere as of the Ear Looking-Giafles, Optical Glafies, and fuch like do afford us in our explication of the Inftru- ments of fight. é she parts. Somwhat we have fpoken concerning the fight, Book 7. chap. 2. Its Inftrumenc is the of the Eyes Bye. which bach many parts, each of which bath its peculiacule, The firftische Cornea
Hy | and theit or nica. or Horny Coat of che Eye, which is tanfparent and void of alcolor, that the vifible ay aft ; {pecies
pbragma 1s Membranous, and conrains no flefhy fubftance, that though che mufculous part. = oe
4
i 4 . what means and wich what Inftruments the operations of the fenfitive faculty are perfor-~ —
planted air required co caufe che Senfe of Hearing. Foras to receive the vifible Species the Organ of
By
ternal Ear cheir fticking out do receive the found, and caufe ic co rebound into the Auditory petigs
Now this Membrane is exceeding dry that it may rightly receive founds: fer Inftruments. - |
peils awed cient be wi may | the i And {oh ditt fran The fed Ho wel N made wh Ich
lomuc that wt does en
thatthe Metal
Ban
Pilg better
Ban
the Vat And h {tion i Thi I relen Watig es 0 ide Wotth
ig | {pecies may pafs chere-through into the Eye, and thac pure and uninfected wath any ftrange Nokon color. cis thicker chan che Air,rhac the {pecies comu g ouc of che Air Cachinner Medium ) Dig f° tatoachicker might be refracted. nay Be Becwixe che Horny Coat, and the Criftalline Humor, the warry humoris placed in che ¢¢ watryg
ie “middle, rran{parenc and void of color for che Reafon aforetaid touching theCornea. Now °*%9- it by } acis chinnerthan che Cornea, that here alfo may be a new refractico of Raies. Mifare _ . Next the wacry humor comes the Uvea Tunica or Grape-skin Goat, which is furnifhed the Vvem fen --wich {uch a blacknefs as is nor to be {een inal che body befides, co che end the {pecies might ‘#nica. ndeed become more cleat, and appear better in the Criftalline humor. For weak Lights do. more nddes | appear in an ob{cure darkith place than ina lightfom. Alfo this Coat feems to have another op End, vig. That over much light which might enter in at che Apple of the Eye, and offend dy the Eyeand che fiphr, might by chis black Coat be intercepted. atthe In che Uvea orthe Grape-skin Coat, chere is an hole which is called the Apple of the the Apple nef Eye, being che door as it were by which che vilible {pecies doencer into the Eye. This of the Eye. at he | hole (chat the fight may be more perfect and diftinct) is much Jets chan che compafs of the Mem Cornea. Yet in fome 1¢ ts larger, in others narrower 5 and chofe chac have it narrower do
fee more fharply, chote chat have it broad are weak-fighted. anted Now the Pupilla or Apple of the Eye is ftrairened and widened, andina light place ape Why it wi- ofthe J «Pe ats narrower, ina‘ obicure place wider: Forfeeingtwo much light hurts the fight, and 4éns and ny, P 2 Weak light ts noc fufficrenc for fight, and in an ob{cure place che vifible object is noc {ufhi- 24779 it a ciently difcerned 5 this Window (as it were) is made in che entrance of che Eye, which may sity I be widened and narrowed, and by widening lec in fo much jighc in an obicure place ag 00k 7 poe be fufficient for fight 3 and by natrowing exclude roo much Light which may offend
f che fighr. hi And in regard of this Conftitution of che Uvea Tunica, there ace three natural manners of i | fight 5_ one is moft perfect, being confticured in an indrvifible point, and whereby we difcern AN | diftindtly che {malleft things: The other is perfect, when we fee vilible objects aca juft di- + il | {tance,and can dift inguifh chem though we do nat difcern the {mailleft parc of every of them : ia | The third is imperfect and confused whereby befides chings juft apainft us (which we fee per ne | fectly ) we do alfo confufedly difcern things on either fide of us; and for this fiphcs fake the Mi, | tLorny Coat is broader thanthe Uvea or Grape-skin Coat, ro che intent thac at one view ie } wemay behold divers things, chough noc al diftinétly, i ’ Now chis is the Cauve of this Difference. Seeing the comprehenfion of a vifible thing is hi made by a Pyramid; and thecertification by its Axis; and only that perpendicular Line ra which 1s called the 4x7, and which isnot refracted, does effectually, plainly,and diftinét- ul dy reprefent the thing; but other Rafts, by how much they are neeret to, or further from it, by ie f fo much the ftronger or weaker they are in repretenting : hence doubtlefs ie comes to pats 3 bt that when the Apple of the Eye is narrower, only the perpendicular in che Pyramid of fighe Alt y | does enter, or wich ic the Rates which are neareft che Axis; when che Apple is wider, lly | more Raies (oblique and refraéted) do enter with the perpendicular. : ue | Nexc che “Uvea ts the Criftalline Humor, which isnot {eated (as fome imagine) inche the ¢yj2 ashy | Centre of the Eye, but in the fore part, and the Membrane compafling the fame divides che falline f } | | Eyeincotwo unequal parts, the foremoft whereof is fourfold leffer chan che hindermoft, 4xmer. : as | And as to the ufe and office of che Criftalline Humor, Authors do noc a liccle vary: For _ Whether DM el one alee erste emailer: Oe ee aa ate ae i c § ale rece : Ts (iecing chac che Glaffie Hu- % is} moris alfo tranipacenc, and much greater than the Criftalline, and Rie hind ie fame ) amare 4 | are of Opinion chae the fight 1s noc rerminated inche Criftalline, bue chae the vilible {pecies of fight 2 a! paffing through the Criftalline are received in the Glaffie Humor, and being refrated are am {gathered into one poinc, and received by che Oprick Nerve: which Opjnion {eems to be very
i proba ble. For feeing refraction ts exceeding neceffary to fightsal chis furnirure of che Eye,and
ints |) the variety of tranf{parenc parts cherein was contrived, that divers refractions mighr be made,
‘i | pus Denes a His, Fueling Humor is more compact than the Watty, cthac a new refra- Mf) €tion might be made therein. st BS. This Criffalline Humor is feated in the fore pare of the Glaflie Humor, fo called becaule sue Glajie nit ic refembles melted Glafs, Its {ubftance is fofter chan che CriftaJline, and lefs fluid chan che Hamor.
LI Wauo. The Quantity hereof is fo grear, chac ic cakes up almoft three quarcers of the Ca~ |
jit 1) vicies of che ee Galen and many others bave hitherto thought, char this Humor was ims }) Made tonouriih che Criftalline; buc falfly : For what need was there of {o great a quanci- vie || ty of che Glaflie humor, ific were only co nourifh che Criftalline ? alfo the Criftalline Hu- pci 1 ;
Chap. 2 :
Of the Body of Man, and its Fun@ions.