548 LIQUID PARTS OF ANIMALS. 



Vauquelin also ascertained, according to Fourcroy, that 

 pigeons' dung contains an acid of a peculiar nature, which in- 

 creases when the matter is diluted with water, but gradually 

 gives place to ammonia, which is at last exhaled in abundance. * 



IV. The white matter voided by dogs who feed chiefly on 

 bones, was formerly used in medicine under the name of album 

 groRcum. It has not been examined by modern chemists, but is 

 supposed to consist in a great measure of the earthy part of the 

 bones used as food, f 



V. M. Lassaigne,J in 1821, made some experiments on the 

 meconium from the foetus of a calf. He found in it the follow- 

 ing substances : 



Mucus, Common salt,. 



Green matter, Carbonate of soda, 



Yellow matter, Phosphate of lime. 



VI. In the year 1815, Dr Prout examined the excrements of 

 the Boa constrictor. $ This substance was solid, of a white colour* 

 inclining to yellow. The fracture was earthy. When it was 

 rubbed against a hard body, it left a white mark like chalk. Its 

 feel was rather more dry and harsh than that of chalk, and 

 it was more friable. The smell was faint and mawkish. The 

 specific gravity, 1-385. It was found composed of, 



Uric acid, #& T. . ; .:<n 9O16 



Potash, >^!'> />:tv? t>4j(n . 3-45 



Ammonia, *">.-({ > r. r w ?l:r;i > 1-70 

 Sulphate of potash with trace of ) 



1. /" U'i/O 



common salt, . . J 

 Phosphate of lime, . ^ 



Carbonate of lime, . 0-80 



Magnesia, 

 Animal matter ; viz. mucus and) 2 . 



a little colouring matter, j 



100-00 



These facts were confirmed by Dr Davy in 1817 1| and by Vau- 

 quelin in 1822.1F Dr Davy proved by dissection that the yel- 



* Fourcroy, x. 70. f Neumann's Chemistry, p. 585. 



| Ann. de Chim. et de Phys. xvii. 304. Ann. Ixxi. 128. 

 Annals of Philosophy, v. 413. || Phil. Trans. 1818, p. 302. 



f Ann. de Chim. et de Phys. xxi. 440. 



