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" Cryjlallme. 



'•"The fccond humour of the eye is the cryflalline, \\hich is as 

 ** tranfparent as the pared cryftal ; and though lefs in quantity than 

 *' the aqueous humour, j'et it is of equal weight, being of a more 

 " denfe and fohd nature ; in confiftency it is fomewhat hke a hard 

 *' js^^y» growing fofter from the middle outwards. Its form is that 

 " of a double convex lens, of unequal convexities, the moft convex 

 " part being received into an equal concavity in the vitreous humour, 



" The cryftalline is contained in a kind of cafe, or capfule, the 

 " fore part of which is very thick and elaftic, the hinder part is thin- 

 " ner and fofter. This capfule is fufpended in its place by a muf- 

 " cle called ligamentum ciliare, which, together with the cryftalline, 

 " divides the globe of the eye into two unequal portions ; the firfl 

 " and fmaller one contains the aqueous humour, the hinder and 

 " larger part the vitreous humour. The cryftalline has no vifible 

 " communication with its capfule, for as foon as this is opened the 

 •' humour within flips clean out. 



" The cryftalline is placed fo, that its axis correfponds with that of 

 " the pupil, and confequently it is not exaftly in a vertical plane di- 

 " viding the eye into tv/o equal parts ; but fomewhat nearer thenofe. 

 " It is formed of concentric plates or fcales, fuccecding each other, and 

 " thefe fcales are formed of fibres elegantly figured, and wound up 

 " in a ftupendous manner ; thefe are connefted by cellular fibres, 

 " fo as to form a tender cellular texture. Between thefe fcales is a 

 " pellucid liquor, which in old age becomes of a yellow colour. The 

 " innermoft fcales lie clofer together, and form at laft a fort of nu- 

 " cleus, harder than the reft of the lens. The cryftalline has no vi- 

 " fible communication with its capfule, fo that when this is opened, 

 " it readily flips out : fome fay, that a fmall quantity of water is 

 " eflfufed round it. Leeuwenhoek has computed that there are 

 "* two thoufand laminic, or fcales, in one cryftalline, and that each 



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