METABOLISM 



575 



an experiment upon a normal man. 1 In this experiment the water in- 

 gestion at meals was increased 3 liters per day during the Water Period. 



INFLUENCE OF HIGH- WATER INTAKE UPON URINE VOLUME AND 

 NITROGEN PARTITION 



The above data indicate an increased catabolism of protein material 

 as is shown by an increased output of total nitrogen upon the first and 

 second days (days 7 and 8) of the Water Period. Part of this increase 

 may, however, have been due to a " flushing" of the tissues rather than 

 to increased catabolism of protein structures. 



Experiments (a) Relation of Water Intake to Volume and Specific Gravity of 

 the Urine. Ingest an ordinary mixed diet for two days. Collect the urine in 24- 

 hour periods. During the first day ingest very little fluid of any kind either at 

 meals or between meals. On the second day ingest as much water as you can 

 without physical inconvenience. A person of average size should have no diffi- 

 culty in drinking 5-6 quarts per day. 



Measure the volume of each day's urine and take the specific gravity. Note 

 the pronounced increase in volume and the low specific gravity of the urine 

 under the influence of high-water ingestion. 



(b) Influence on Protein Catabolism. That water stimulates protein catabolism 

 may easily be demonstrated as follows: Ingest a uniform diet (milk, crackers, 

 butter, peanut butter and water) for a period of four days. During the first two days 

 ingest your customary volume of water per day. During the last two days increase 

 the water ingestion to 5-6 liters per day. Collect urine in 24-hour periods and 

 analyze for total nitrogen by Kjeldahl method (see Chapter XXVI and Note on 

 page 589). Note the increased excretion of nitrogen under the influece of high- 

 water intake. If time permits other nitrogenous urinary constituents may be 

 determined (see table above). 



1 Fowler and Hawk: Jour. Expt. Med., 12, 388, 1910. 



