54 CHEMICAL PHYSIOLOGY. 



and ether, I have found in it considerable quantities 

 of cholesterine, fat, and % paralbuinen, but neither bile 

 nor sugar. Having during many years, and in many 

 cases, observed considerable quantities of leucine in the 

 liver, and having frequently experienced great difficulty 

 in isolating this substance, and separating it from others, 

 I subjected to a special study the compounds of leucine 

 with metals, and discovered a new copper compound 

 which renders leucine entirely insoluble in water and 

 neutral fluids. For the extraction of hypoxanthine and 

 xan thine I have also devised special processes. 



Kidneys. rj^g kid ne ys contain much blood, collagene fibres, and 



some fat ; to water extraction they yield chlorrhodinic 

 acid, uric acid, and bodies resembling hypoxanthine 

 and xanthine, but urea is scarcely obtainable from them. 

 Cystine and inosite have on some rare occasions been 

 met with. The chemical changes of the kidneys in 

 diseases have not yet been sufficiently examined. 



The urine. The urine is the secretion of the kidneys. It is the 

 lixiviated refuse from the chemical processes of the 

 body. It contains a yellow colouring matter, urochrome, 

 which by chemolysis yields various remarkable products 

 of decomposition. The first is uromelanine, C 36 H 43 N 7 10 , 

 a most interesting substance, with an atomic 

 weight of 733, being one of the highest at present 

 established in organic chemistry. Accompanying 

 uromelanine there is a small quantity of a matter which 

 by treatment with sulphuric acid yields the reaction and 

 spectrum of cruentine, termed paramelanine. The 

 next product is uropittine, not as yet sufficiently studied. 



