422 Studies in Water Drinking [April-July 



from food, but drinks plenty of water. In fact the mental faculties 

 may be sharpened by a short fast. This point was clearly shown in 

 one of our fasting tests. A member of the chemical staff, a candi- 

 date for the Ph.D. degree, was the subject of the test. During a 

 seven-day fast he worked hard in preparation for his final examina- 

 tions and ingested nothing but water. He subsequently stated that 

 he feit he had accomplished more work, mentally, during the seven 

 days of the fast than in any other period of equal length during his 

 entire course. This Observation is in sharp contrast with another 

 Observation made by my associates and myself. In this case we 

 were to study the influenae of an increased water consumption. In 

 Order that a pronounced difference in the volume of water ingested in 

 the different experimental periods might be secured, the amount of 

 water given the subjects of the experiment (men) during the pre- 

 liminary period was reduced to a minimum. That we had exceeded 

 the physiological minimum was soon apparent; headaches, nervous- 

 ness, loss of appetite, digestive disturbances and inability to do ac- 

 curate chemical work were evident. It was necessary, therefore, to 

 increase the water content of the diet, and with this single change 

 the experiment proceeded satisfactorily. The incidents just men- 

 tioned serve to emphasize the fact that one may live longer without 

 food than without water, 



It is also a demonstrated fact that the length of time an animal 

 is able to fast will be considerably increased if it be given a uniform 

 volume of water daily instead of being subjected to a "complete" 

 fast, 1. e., without food or water. This fact was emphasized in one 

 of our experiments in which a Scotch collie dog fasted for periods of 

 117 and 105 days respectively in successive years, the animal having 

 been given a uniform volume of water daily by means of a stomach 

 tube. 



The vast majority of the processes and activities associated with 

 the digestion and absorption of our food, the utilization of the 

 digestion products as a source of energy and for constructive pur- 

 poses, as well as the transformations associated with the excretion of 

 waste products, are at basis chemical. These chemical reactions 

 take place only in Solution. A solvent is necessary ; the best, most 

 available and least injurious is water. When we turn to respiration 



