CHEMICAL PHYSIOLOGY. 55 



Then there is omicholine, empirical formula C 33 H 38 N0 5 , omi 

 an organic base with fluorescent properties and a 

 peculiar spectrum, and omicholic acid, C 15 H 33 N0 4 , also 

 fluorescent, but slightly differing in its spectrum and 

 composition from omicholine ; further, acetic and formic 

 acid. From these products it is evident that urochrome 

 must possess a very high atomic weight ; it may, per- 

 haps, be a derivate of hematocrystalline ; uromelanine no 

 doubt represents the nucleus of hematine. The 

 ingredient which occurs in urine in the largest quantity 

 is urea, CH 4 N 3 0, of which a man secretes about 30 Urea . 

 grammes in twenty-four hours. Then there is kreati- 

 nine C 4 H 7 N~ 3 0, the same as that which occurs in the 

 muscles. It is partly changed into kreatine, C 4 H 9 N 3 3 , 

 by taking up an atom of water during the process of 

 preparation. From kreatinine is derived sarkosine, sarkosm 

 which is isomeric, or perhaps identical with alanine 

 CoELNOo. There is further contained in urine uric acid, Uric :ici<1 



o / ' group. 



C 5 H 4 N 4 3 , which may form calculi and cause much 

 trouble, and a series of bodies being less oxydised than 

 uric acid, namely, guanine, C 5 H 5 N 5 0, hypoxanthine, 

 CgHJS^O, and xanthine, C 5 H 4 N 4 3 . Further, there is 

 an acid which from having been first discovered in 

 horses' urine is termed hippuric, C 9 H 9 N0 3 , remarkable ; 

 by its consisting of a combination of glykokoll C 3 H 5 N0 3 , 

 and benzoic acid, C 7 H 6 3 , less an atom of water, H 3 O, 

 and by its being formed in considerable quantity 

 in the human body when benzoic acid is being 

 taken, or greengages are consumed. The extractives 

 are at least three in number; of these I have fully 

 identified kryptophanic acid which if considered 



