of the Humours of the Ei/e. S6Q 



sheep's eyks. 

 Aqueous Humour, 



The aqueous humour is a clear transparent liquid, of the 

 specilic gravitv of 10090*, at 6o" of Fahrenheit. When 

 fresh, it ha^ verv little smell or taste. 



It causes very little change in the vegetable re-active co- 

 lours; and this little would not, I believe, be produced im- 

 intdiatelv after death. I imagine it to be owuig to a gene- 

 ration of amuionia, sonic traces of wiiich I discovered. 



When exposed to the air, at a moderate temperature, it 

 evaporates slowlv, and becomes slightlv putrid. 



W'hen made to boil, a coagulum is formed, but so small 

 as hardiv to be perceptible. Evaporated to dryness a resi- 

 duum remains, weigliing not more than 8 per cent, of the 

 original liquor. 



Tannin causes a precipitate in the fresh aqueous humour 

 both before and after it has been boiled, and consequently 

 shows the presence of gelatine. 



Nitrate of silver causes a precipitate, which is nutriate of 

 silver. No metallic salts, except those of silver, alter the 

 aqueous humour. 



From these and other experiments it appears that the 

 aqneous humour is composed of water, albumen, gelatine, 

 aiul a muriate, the basis of which I found to be soda. 



I have omitted speaking of the action of the acids, of the 

 alkalis, of alcohol, and of other re-agents, upon this hu- 

 moiu\ It is such as mav be expected in a solution of al- 

 bumen, of gelatine, and of muriate of soda. 



Crystalline Humour. 



To follow the order of their situation, the next of the 

 kumours is the crvstalline. 



This dirti.TS very materially from the others. 



Its specilic gravity is 11 000. 



When fresh, it is neither acid nor alkaline. It putrefiesi 

 very rapidly. It is nearly all soluble iu cold water, but is 

 partly coagulated by heat. Tannin gives a very abundant 

 precipitate ; but I could not perceive anv traces of muriatic 

 acid when I had obtained the crystalline quite free from the 

 ether humours. It is comi)osed, therefore, of a smaller 

 proportion of water than the others, but of aanuch larger 

 proportion of albumen and gelatine. 



* All these specific gravities aie mean proportionals of scvcr.il cxpe- 

 rinicnTs. Tiie t-yts of rh(- sr^me species of animal do not differ mw\\ in' 

 tilt upccii'c gravity vt' tJioir liumoiiri. 



yitreous 



