ALL THE ELEMENTS OF THE BLOOD. 133 



It will surely appear remarkable that this manner 

 of viewing the subject has led to the true formula 

 of bile, or, to speak more accurately, to the most 

 correct empirical expression of its composition ; 

 and has furnished the key to its metamorphoses, 

 under the influence of acids and alkalies, which had 

 previously been sought for in vain. 



24. When fresh drawn blood is made to trickle 

 over a plate of silver, heated to 140°, it dries to 

 a red, varnish-like matter, easily reduced to pow- 

 der. Muscular flesh, free from fat, if dried first in 

 a gentle heat, and then at 212°, yields a brown, 

 pulverizable mass. 



The analyses of Playfair and Boeckmann (28) 

 give for flesh (fibrine, albumen, cellular tissue, and 

 nerves) and for blood, as the most exact expres- 

 sion of their numerical results, one and the same 

 formula, namely, C48N6H39O15. This may be called 

 the empirical formula of blood. 



25. The chief constituent of bile, according 

 to the researches of Demarc^ay, is a compound, 

 analogous to soaps, of soda with a peculiar sub- 

 stance, which has been named choleic acid. This 

 acid is obtained in combination with oxide of lead, 

 when bile, purified by means of alcohol from all 

 matters insoluble in that menstruum, is mixed with 

 acetate of lead. 



Choleic acid is resolved, by the action of nuiriatic 

 acid, into ammonia^ taurine^ and a new acid, cholo- 

 idic acid, which contains no nitrogen. 



