426 Studies in Water Drinking [April-July 



the influence of a defensive enzyme and made available for the uses 

 of the organism. The conditions are entirely different when the 

 cane sugar is ingested. In this event the carbohydrate proceeds 

 essentially unaltered until it reaches the intestinal juice, where, 

 through the instrumentaHty of the inverting enzyme invertase, or 

 sucrase, a molecide of water is added to the disaccharide molecule, 

 causing the CioHooOu to split into two monosaccharide molecules, 

 which are absorbed and utihzed by the body. The addition of the 

 tiny molecule of water (H2O) has yielded a 100 per cent. nutritional 

 efficiency from the nutritionally inefficient cane sugar. 



Many important experiments have been made to demonstrate the 



influence of an increased water Ingestion upon the processes of 



metabolism. Inasmuch as protein is a very important dietary con- 



stituent the main emphasis in these tests has been placed upon the 



metabolism of protein. These experiments show that an increased 



consumption of water is followed by an increased Output of nitrogen 



in the urine. As to the history of this nitrogen there is a difTerence 



of opinion, and two hypotheses have been suggested. Some inves- 



tigators teil us that the increased nitrogen is due to the " flushing " 



of the tissues and the consequent removal of nitrogenous waste prod- 



ucts which had accumulated there. Other investigators teil us that 



the increased nitrogen has its origin in an increased protein catabo- 



lism. The first really definite evidence favoring either of these 



views was furnished by certain of our experiments. It is well 



known that all cells contain nucleoprotein. By decomposition this 



nucleoprotein yields purin bases and uric acid. In certain lower 



animals, in particular, oxidation of uric acid may yield allantoin. 



The nitrogen in the form of purin bases, uric acid, and allantoin is 



termed " total purin nitrogen." Inasmuch as this form of nitrogen 



has its origin in the cell nucleus we may consider that an increased 



Output indicates stimulated cellular activity and increased tissue dis- 



integration. In one of our tests a dog was fasted 59 days, receiving 



700 cc. of water daily. The water ingestion was then increased 



200 per Cent, for four days, making the water ingestion 2100 cc. per 



day. Under these conditions an increased Output of total purin 



nitrogen was observed. This increased excretion of purin nitrogen, 



which followed the increase in the water ingestion to 2100 cc. per 



