URINE. 291 



the fermentation of carbohydrates and the putrefaction of proteins. 

 The acids containing the fewest carbon atoms (formic and acetic) 

 are found to be present in larger percentage than those which con- 

 tain a larger number of such atoms. The volatile fatty acids occur 

 in normal urine in traces, the total output for twenty-four hours, 

 according to different investigators, varying from 0.008 gram to 

 0.05 gram. 



Pathologically, the excretion of volatile fatty acids is increased 

 in diabetes, fevers, and in certain hepatic diseases in which the 

 parenchyma of the liver is seriously affected. Under other patho- 

 logical conditions the output may be diminished. These variations, 

 however, in the excretion of the volatile fatty acids possess very 

 little diagnostic value. 



CH 3 



PARALACTIC ACID, CH(OH) 



Paralactic acid is supposed to pass into the urine when the supply 

 of oxygen in the organism is diminished through any cause, e. g., 

 after acute yellow atrophy of the liver, acute phosphorus poisoning 

 or epileptic attacks. This acid has also been found in the urine of 

 healthy persons following the physical exercise incident to pro- 

 longed marching. Paralactic acid has been detected in the urine 

 of birds after the removal of the liver. Underbill reports the oc- 

 currence of this acid in the urine of a case of pernicious vomiting 

 of pregnancy. 



CH 2 -CO-NH-CH 2 -COOH. 

 /\ 



PHENACETURIC ACID, 



Phenaceturic acid occurs principally in the urine of herbivorous 

 animals but has frequently been detected in human urine. It is pro- 

 duced in the organism through the synthesis of glycocoll and 

 phenylacetic acid. It may be decomposed into its component parts 

 by boiling with dilute mineral acids. The crystalline form of 

 phenaceturic acid (small rhombic plates with rounded angles) re- 

 sembles one form of uric acid crystal. 



PHOSPHORIZED COMPOUNDS. 



Phosphorus in organic combination has been found in the urine 

 in such bodies as glycerophosphoric acid, which may arise from 



