The workes of that famous chirurgion Ambrose Parey translated out of Latin and compared with the French. by Tho: Johnson. Whereunto are added three tractates our of Adrianus Spigelius of the veines, arteries, & nerves, with large figures. Also a table of the bookes and chapters.

CHAP. VI. Of the Muscles, Coats, and humors of the Eye.

THere are six Muscles in the Eye, of which four perform the four direct motions of the Eye: they arise from the bottom of the Orb, and end in the midst of the Eye, encompas∣sing the optick nerve. When they are all moved with one endeavour, they draw the Eye inwards. But, if the upper only use its action, it drawes the eye upwards; if the lower, down∣wards; if the right, to the right side; if the left, to the left side.

The two other muscles turn the Eye about; the first of which being the longer and slenderer, arises almost from the same place, from which that muscle arises, which draws the eye to the right side to the greater corner. But when it comes to the utmost part of the inner angle, where the Glandula lacrymalis is seated, it ends in a slender Tendon, there piercing through the middle membrane which is there, as through a ring; from whence it presently going back, is spent in a right angle towards the upper part of the Eye, betwixt the insertions of those two muscles, of the which one draws the Eye upwards, the other directly to the outward corner, as it is observed by Fallo∣pius, or rather, which I remember, I have alwayes observed, they turn between the muscles which move the eye upwards, and to the inner corner.

This fifth muscle when it is drawn in towards its beginning, so draws the eye with its circular tendon, that it carries it to the greater corner.

The sixt muscle is contrary to that; for it hath its original from the lower part of the orb at a small hole, by which a nerve of the third conjugation passes forth; and being that it is most slen∣der, whilst it ascends transversly to the outward corner, it involves the eye so also, that it is inserted in it by a small Tendon, so that the Tendons of them both are oftentimes taken but for one. That thou mayst truly and accurately observe this anatomical description of the eye, the eye must not be pluckt out of its orb, but rather the orb it self must be broken and separated.

For thus thou shalt certainly and plainly see the forementioned original of the muscles. For the five coats, the first which is first met with in dissection, comes from the Pericranium, and is extended over all the white of the eye, even to the Iris or Rain-bow. The duty of it is to strength∣en, bind and contain the eye in its orb, wherefore it had the name Conjunctiva; others call it Adnata, or Epipephycos.

The second is called the Cornea, because it resembles a horn in colour and consistence; this

coat differs and varies from it self; for in the forepart, as far as the Iris goes, it is clear and per∣spicuous, but thick and obscure in the hind part, by reason of the diverse polishing. On the fore-part it is dense, that it may preserve and contain the Crystalline and waterish humor, but with∣all transparent, so to give the object a free passage to the Crystalline. It hath its original from the Crassa Meninx, proceeding forth from the inner holes of the orb of the eye, for it compasses the eye on every side.

The third is called Uvea or Grapy coat, because in the exterior part it represents the colour of black grape; it arises from the Pia Mater, and encompasses all the eye, except the pupilla or apple of the eye, for here being perforated, it adheres to the horny coat by the veins and arte∣ries which it communicates to it for life and nourishment. But when it arrives at the Iris, then forsaking the Cornea, it descends deep in the eye, and in some sort is turned about the Crystalline humor, to which also it most firmly adheres, so bounding the waterish humour, and also prohi∣biting that the Albugineous humor do not overwhelm the Crystalline. This grapy coat is as it were dyed on the inside with divers colours, as black, brown, blew, or green like a rain-bow, and that for these ensuing benefits.

The first is, if that it had been tinctured with one colour, all objects would have appeared of the same colour, as it comes to pass when we look through green or red glass. But it must be coloured, that so it may collect the spirits dissipated by the Sun and seeing.

[illustration]

The figure of the Eye.

• Table 3. Figure 1. sheweth the Membranes and humors of the eye, by lines drawn after the manner of a true Eye.
• F. 2. sheweth the horny coat with a portion of the optick nerve.
• Fig. 3. sheweth the same divided by a transverse section.
• Fig. 4. sheweth the Uvea, or grapy coat, with a portion of the Optick Nerve.
• Fig. 5. The grapy coat of a Mans Eye.
• Fig. 6. The Horny, Grapy, and the Choroides.
• Fig. 7. The Interiour superficies of the Grapycoat.
• Fig. 8. The posterior part of the hornycoat together with the said net-coat separated from the Eye.
• F. 9. the coat of the vitreous or glassy humor called Hyaloides.
• Fig. 10. The humors joyned together.
• Fig. 11. The former part of the Crystallyne.
• Fig. 12. The Crystalline humor covered yet with his coat.
• Fig. 14. The Crystalline of a Mans Eye.
• Fig. 15. His Coat.
• Fig. 16. The watery humor disposed upon the Crystalline round about.
• Fig. 17. The hairy processes beamingly sprinkled through the foreside of the coat of the glassie humor.
• Fig. 18. The foreside of the glassie humor.
• Fig. 19. The place of the watery humor.
• Fig. 20. The glassie humor containing or comprehending the Crystalline.

The explication of the first Figure by it self.

• a, The Crystalline humor.
• b, the glassie humor.
• c, the watery humor.
• d, the utmost Coat called Adnata.
• e, the dark part of the Horny-tunicle, which is not transparent.
• f, the Grapy coat called Retiformis.
• h, the coat of the glassie humor called Hualoides.
• i, the coat of the Crystalline.
• kk, the hairy processes called Processus ciliares.
• l, the impression of the Grapy coat where it de∣parteth from the thick coat.
• m, the horny coat, a part of the thick coat.
• nn, the fat betwixt the Muscles.
• o, the optick Nerve.
• p, the Dura meninx.
• q, the Pia mater, or thin meninx.
• rr, the Muscles.

The explication of the other 19. Figures to∣gether.

• a 2, 4, 8, the Optick nerve.
• b, 2, 4. the thin Meninx cloathing the Nerve,
• c, 2, 3. the thick Meninx cloathing the Nerve.
• d, 8, the posterior part of the horny coat.
• e, 8, the coat called Retina gathered together on an heap.
• f. 2, 3. the rain-bow of the eye.
• g, 2, 3. the lesser circle of the Eye or the pupilla.
• h 2, 3. Vessels dispersed through the Dura meninx.
• i 3, 6, the grapy coat, but i, in the 3. Fig. sheweth how the vessels do joyn the hard membrane with the grapy coat.
• k 6. the horny or hard membrane turned over.
• ll 3, 4. Certain fibers and strings of vessels, where∣by the grapy coat is tyed to the horny.
• mm 4, 5 the impression of the grapy coat where it recedeth or departeth from the horny coat.
• nn 4, 5, 6, 7. the pupilla or apple of the eye.
• oo 7. the ciliar or hairy processes.
• p 7. the beginning of the grapy coat made of a thin

[illustration]

• membrane dilated, but p in the 17. figure sheweth the Ciliar processes sprinkled through the fore-part of the glassie humor.
• r 9, the bosom or depression of the glassie humor receiving the Crystalline.
• s 12, 15, the bredth of the Coat of the Crystalline.
• t 12, 13, 14, 16, the posterior part of the Crystalline humor, which is sphe∣rical or round.
• u 11, 14, 20, the fore-part of the same Crystalline depressed.
• x 10, 20, the amplitude of the glassie humor.
• y 10, 16, 19, the amplitude of the watry humor.
• z 19, the place where the glassie hu∣mour is distinguished from the watry by the interposition of the Hyaloides or coat of the glassie humor.
• α 10, 16, the place where the Grapy-coat swimmeth in the watry humor.
• β 18, the cavity or depression of the glassie humor which remaineth when the Crystalline is exempted or taken from it.
• δ 19, the cavity or de∣pression of the watry humor made by the same means.

Thirdly, it was convenient it should be painted with infinite variety of colours for the pre∣servation of the sight. For as the extream colours corrupt and weaken the sight, so the middle refresh and preserve it, more or less, as they are neerer, or further remote from the extreams. It was fit it should be soft, that so it might not hurt the Crystallyne humor upon whose circumfe∣rence it ends; and perforated in the part objected to it, lest by its obscurity it should hinder the passage of the objects to the Crystalline, but rather that it might collect by its blackness, as a con∣trary, the great, and as it were, diffused variety of colours, no otherwise than we see the heat is strengthened, by the opposition of cold; some call this coat Choroides, because it is woven with many veins and arteries, like the coat Chorion which involves the infant in the womb.

Now follows the fourth coat called Amphiblestroides or Reti-formis, the Net-like coat, because proceeding from the Optick-nerve dilated into a coat, it is woven like a Net with Veins and Arteries which it receives, from the grapy-coat, both for the life and nourishment both of it self, also of the glassie humor which it encompasses on the back-part. The principal commodity of this coat is, to perceive when the Crystalline humor shall be changed by objects, and to lead the visive spirit instructed or furnished with the faculty of seeing, by the mediation of the glassie hu∣mour, even to the Chrystallyne, being the principal instrument of Seeing. It is softer than any o∣ther coat, lest the touch of it should offend that humor. Wherein thou wilt admire the singular order of Nature, which as in other things it passes not from one extreme to another, unless by a Medium; so here it hath not fitted the hard horny-coat to the soft humors, but by interpositi∣on of divers media of a middle consistence. For, thus, after the harder coats Adnata and Cornea, it hath placed the Grapy-coat; by so much softer than these two, as the Net-like coat is softer than it, that thus it might pass from extreme to extreme, as it were, by these degrees of hardness and softness.

The fifth and last coat is called Arachnoides, because it is of the consistence of a Spiders web. And we may well resemble this coat, to that skin of an Ynion which exceeds the other in clear∣ness, whiteness, and thinness. This Araneosa or Cobweb-like coat encompasses the Crystalline humor on the fore-side, peradventure that so it might defend it, as the chief instrument of seeing, if the other humors should at any time be hurt. It hath its original from the excrementitious hu∣midity of the Crystalline humor, hardned into that coat by the coldness of the adjacent part; ab∣solutely like the thin skin which encompasses the white of an Egg.

The first humor of the Eye is called Aqueus, or waterish, from the similitude of water; it is seated between the transparent part of the Horny-coat, the portion of the Crystalline humor ly∣ing towards the Apple of the Eye, and that reflection of the Grapy-coat which comes from the Iris, to the circumference of the Crystalline humor, that filling the empty space it may distend the Cornea, and so hinder the falling thereof upon the Crystalline which would spoil the sight; as also that by its moisture it might hinder the drying of the Crystalline humor. Peradventure it is made of the whayish humor sweating out of the vessels of the coats, having their orifices for the most part in that place, where this waterish humor resides. The second humor and middlemost in situation is called the Crystalline, because it imitates Crystal in the brightness and colour; if so be, that we may attribute any colour to it. For indeed, it was fit, that none of the three humors should be tinctured with any colour, as those which would be the instruments of sight, lest they might beguil us in seeing, as red and green spectacles do; for, that is true, which we have read written by the Philosopher; That the subject or matter, appointed for the reception of any form, should want all impression thereof. Hence Nature hath created a formless Matter, the hu∣mors of the Eyes without colours, Wax without any figure, the Mind without any particular knowledg of any thing, that so they might be able to receive all manner of forms. The figure of the Crystalline humor is round, yet somewhat flatted on the foreside, but yet more flatted be∣hind, that so the objects might be the better retained in that, as it were, plane figure, and that they might not fly back as from a Globe, or round body, in which they could make but short stay; lest it might be easily moved from its place by the force of any thing falling or hitting against it, because that body which is exactly round touches not a plain body, but only in a point or prick. Half this humor swims in the glassie humor, that so it may be nourished from it by transposition of matter; or rather (seeing it is encompassed on every side with the fifth coat, that the matter cannot easily be sent from the one into the other) by the benefit of the vessels produced even un∣to it as well by the Net-like coat as the by the Grapy; but it is filled with a bright spirit on the fore-part, which lies next to the waterish humor, and the space of the Apple of the Eye.

Of which thing this is an argument, that as long as a man remains alive, we see the Eye every way full, and swoln, but lank and wrinkled when he is dead; besides also, one of the Eyes being

shut, the Pupilla of the other is dilated by the spirit compelled to fly thither. And also for the same cause the horny-coat is wrinkled in very old men, and the Pupilla is straitned by the wrinckles subsiding into themselves, which is the cause that they see little, or not at all; for by age and success of time the humor is consumed by little and little, the implanted spirit vanishes away, and smaller quantity of spirits flow from the Brain, as from a fountain which is also exhausted. The horny-coat at his original, that is, in the parts next the Iris, seemeth to be very nigh the Crystal∣line humor, because all the coats in that place mutually cohere as touching one another; but as it runs further out to the Pupilla, so it is further distant from the Crystalline. Which you may easily perceive by Anatomical dissection, and the operation of touching or taking away a Catarrhact: for whereas a Catarrhact is seated between the horny-coat and Crystalline humor, the needle thrust in, is carryed about upwards, downwards, and on every side through a large and free space, neither touching the horny-coat nor Crystalline humour, by reason these bodies are severed by a good distance filled with spirit and a thin humour. The use of it is, that it may be like a Looking-glass to the faculty of Seeing carryed thither with the visive spirit.

The third and last humor is the Vitreus, the Glassie, or rather Albugineous humor; called so, be∣cause it is like molten Glass, or the white of an Egg. It is seated in the hind-part of the Crystal∣line humor, that so it may in some sort break the violence of the spirit flowing from the Brain in∣to the Crystalline humor, no otherwise than the watry humor is placed on the fore-side of the Crystalline to hinder the violence of the light and colours entring that way. This Glassie humor is nourished by the Net-like coat.

We have formerly spoken sufficiently of the Nerves of the Eye: Wherefore it remains that we speak of the veins. Some of these are internal, carryed thither with the coats of the vessels of the Brain; other some externall stretched over the external parts of the Eye, as the Muscles, and coat Adnata; and by these veins, inflammations and redness often happen in the external parts of the Eye: for which the Vena pupis must be opened, and Cupping-glasses, and Horns must be ap∣plyed to the nape of the neck and shoulders: as, in the internal inflammations of the Eye, the Cephalick-vein must be opened to avert and evacuate the morbifick humor.

Notes

• The number, site and action of the muscles.
• The 5 coats of the eye.
• 1 Conjunctiva, or Adnata.
• 2. Cornea, or the Horny coat.
• 3. Uvea, or the grapy coat.
• Why the gra∣py coat re∣sembles divers colours.
• Amphiblestroi∣des or Reti-for∣mis, Net-like coat.
• An Anatomi∣cal Axiom.
• 5 Arachnoides, sive Araneosa, the Cobweb-coat.
• The 3 humors of the Eye.
• 1 Aqueus, or watery.
• 2 Crystallinus, Crystalline.
• A Philosophi∣cal Axiom.
• Gal. Cap. 5. lib. 10. de usu part.
• In what place Catarrhact or a Suffusion breeds.
• 3 Vitreus seu Al∣bugineus, that is Glassie, or like the white of an Egg.
• The veins of the Eye.
• VVhat veins may be opened in what in∣flammations of the Eyes.