526 LIQUID PARTS OF ANIMALS. 



neither carbonate nor phosphate of an alkali, but a considerable 

 quantity of phosphates of lime and magnesia, with traces of per- 

 oxide of iron. 



Henri and Chevalier extracted by alcohol and water the mat- 

 ter of respiration from the hair of cows.* They obtained, 



1. A fatty matter. 



2. A brownish-black matter. 



3. A bitter substance soluble in water. 



4. A yellow colouring matter, soluble in alcohol and water. 



5. Carbonate and hippurate of soda. 



Dr Donne assures us that, in a state of health, the skin and 

 the matter of perspiration is always acid.f Berthollet had ob- 

 served this many years ago, and concluded that the acid present 

 was the phosphoric. J 



Thenard obtained acetic acid, and Berzelius has rendered it 

 probable that the true acid of sweat is the lactic. Though dogs 

 and cats do not sweat, yet their skin, according to Donne, is al- 

 ways acid, while that of rabbits and horses is alkaline. Donne 

 has observed that the matter of perspiration frequently becomes 

 alkaline during disease, especially during those of the chronic 

 kind. 



CHAPTER XX. 



OF THE LIQUOR OF THE AMNIOS. 



THE foetus in the uterus is enveloped in a peculiar membrane 

 or covering, to which anatomists have given the name oi amnios. 

 Within this amnios there is a liquid, distinguished by the name 

 of liquor of the amnios, which surrounds the foetus. This liquid 

 in women is a fluid of a slightly milky colour, a faint but not 

 disagreeable smell, and a saltish taste. The white colour is owing 

 to a curdy matter suspended in it, for it may be rendered tran- 

 sparent by filtration. 



Its specific gravity, as determined by Vauquelin and Buniva, 

 is 1*005. || These chemists analyzed it in 1800. It was again 



Jour, de Pharm. xxv. 422. f Ann. de Chim. et de Phys. Ivii. 401. 



J Jour, de Phys. xxviii. 275. Ann. de Chim. et de Phys. Ivii. 401. 

 II Ann. de Chim. xxxiii. 270. 



