76 MANUAL OF PHYSIOLOGY. 



of septic agencies, in a watery solution, urea takes up two atoms 

 of water and is converted into carbonate of ammonium : 

 CO(NH 2 ) 2 + 2H 2 = CO(ONH 4 ) 2 . 



The so-called alkaline fermentation of urine depends upon this 

 change. The reader is referred to the Chapter on Excretions, 

 where more complete information is given. 



Kreatin, C 4 HN 3 O a , occurs in muscle and many other textures. 

 It may be converted into kreatinin by the action of acids by 

 simple dehydration. It can also be split up into sarcosin and 

 urea. 



Kreatinin, C 4 H 7 N 3 O, is a dehydrated form of kreatin, which is 

 a normal constituent of urine. In watery solutions it is slowly 

 converted into kreatin. 



Allantoin, C 4 H G N 4 O 3 , found in the allantoic fluid and the urine 

 of the foetus and pregnant women. It is crystallizable, and is 

 converted into urea and allantoic acid by oxidation. 



Glycin (Glycocnll or Glycocine), C.,H 2 (NH 2 )O.OH, 

 is regarded as amido-acetic acid. It does not occur free in the 

 body, but enters into the composition of the bile acids and hip- 

 puric acid. It is soluble in water. 



Lewcm,C 6 H 10 (NH 2 )O.OH, 



amido-caproic acid, is found in the secretion of the pancreas 

 and some other glands. It is one of the principal products of 

 the decomposition of albuminous bodies, from which it can be 

 obtained by boiling with sulphuric acid. 



Tyrosin, C 9 H U NO 3 , though belonging to a distinct chemical 

 series (aromatic), is only found in company with leucin in the 

 decomposition of albuminous bodies, and normally in the pan- 

 creatic secretion. 



Taurin, C 2 H 7 N0 3 S, or 2 



is a constituent of one of the bile acids, and is also found in 

 muscle juice. It may be regarded as amido-ethyl-sulphonic 

 acid. 



Uric Acid, CsH^N^Os (dibasic), is found in large quantities in 

 the excrement of birds and reptiles, but in a small and variable 



