METABOLISM 



585 



The collection and analysis of the urine during a short fast (three 

 to seven days) will demonstrate many important facts. The following 

 table, which contains data from fasting tests made in the author's 

 laboratory, 1 illustrates some of the points in which fasting metabolism 

 differs from normal metabolism: 



METABOLISM IN FASTING 



Abstinence from food for a few days can in no way operate to the 

 disadvantage of a normal person. In fact individuals affected with 

 certain types of gastro-intestinal disorders are benefited by fasting. 

 The fasting treatment 2 is also being used with success in cases of diabetes 

 mellitus. 



In order to determine experimentally how the fasting metabolism differs from 

 normal metabolism proceeds as follows : Ingest an ordinary mixed diet and col- 

 lect your urine (see page 565) for a day. Measure the volume and analyze the 

 sample for total nitrogen, ammonia, creatine, sodium chloride, total phosphates 

 and acidity 3 (for methods see Chapter XXVI). For the next few days (three to 

 seven as desired) ingest nothing but water and collect the urine accurately and 

 analyze for the constituents enumerated above. Tabulate your results and 

 compare them with those given in the table above. 



23. Synthesis of Hippuric Acid in Human Body. Hippuric Acid is 

 present in human urine in small amount, about 0.7 gram being excreted 



1 The chloride, phosphate and acidity determinations were collected during one seven- 

 day fast and the other data collected during a different fast on the same man. (See 

 Howe, Mattill and Hawk: Jour. Amer. Chem. Soc., 33, 568, 1911; and Wilson and Hawk: 

 Jour. Amer. Chem. Soc., 36, 137, 1914-) 



2 Allen: Amer. Jour. Med. Sci., 150, 480, 1915. 



3 A more accurate experiment may be carried out by ingesting a uniform diet of known 

 composition (see page 569) for a few days before the fast. 



