68 MANUAL OF PHYSIOLOGY. 



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

 ple dehydration. It can also be split up into sarcosiu 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 6 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. 



C 2 H 3 



Glyein ( Glycocoll or Glycocine), C 2 H 2 (NH 2 )O.OH, or H N, 



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. 



C.H.,0,) 



Leudn, C 6 H 10 (NH 2 )O.OH, or y N, amido-caproic acid, 



H ) 



is found in the secretion of the pancreas and some other glands. 

 It is one of the principal products of the decomposition of albu- 

 minous bodies, from which it can be obtained by boiling with sul- 

 phuric acid. 



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

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

 decomposition of albuminous bodies, and normally in the pan- 

 creatic secretion. 



Taurin, C 2 H 7 NO 3 S, or 25 SO 3 , is a constituent of one of 



the bile acids, and is also found in muscle-juice. It may be re- 

 garded as amido-ethyl-sulphonic acid. 



Uric Add, C 6 H 4 N 4 O 3 (dibasic), is found in large quantities in 

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

 quantity in the urine of man. Traces have been found in many 

 tissues, in some of which large quantities accumulate as the result 

 of pathological processes (gout). It forms salts which are much 

 oluble in cold than in hot water, and make the common 

 sediment in urine. The acid salts are less soluble than the neutral. 

 The common test for uric acid consists of slowly evaporating the 



