92 General Aspects of Fasting [Sept. 



from fasting has not been determined. The probable reason is the 

 failure of some organ or life process (27) and not the depletion of 

 all possible nutritive material. From our experiments (10) it 

 would appear that a certain definite minimal proportion of nitrogen- 

 holding substance must be present in the body for life to exist. 



Fasts have been reported upon men covering periods of from 

 2-50 days, upon dogs as long as 117 days and Salamanders for 125 

 days. In each of the extreme cases, the subjects were subsequently 

 fed and they returned to normal. The influenae of repeated fasting 

 upon the resistance of the animal to subsequent fasts is a phenome- 

 non which appears to be intimately associated with hibernation. As 

 has been shown by Russian investigators (20), and more recently in 

 our laboratory (10), repeated fasting decreases the rate of metab- 

 olism in each succeeding fast. A French investigator (21) has 

 shown that repeated fasting, in which the subjects were alternately 

 fasted and fed during equal periods of about a week each, resulted 

 in the ultimate death of the animals. From the experimental data 

 Et band it seems that where the animal is permitted to recover 

 completely from a fast before it is subjected to another, there will 

 be an increased resistance to the ravages of the succeeding fast. 



The number of men who have made a study of the changes 

 which take place as the result of fasting is so great that it is difficult 

 to name those who have made the most important contributions 

 upon this subject without doing an injustice to others. The inves- 

 tigations of Cathcart (4) in England and of Benedict (2) in this 

 country, upon men, are the most extensive that have been con- 

 ducted with the more refined methods of analysis which we possess 

 today. The names of Succi, Cetti and Breithaupt stand out in the 

 literature as the subjects of important experimental fasts. 



What changes take place in an organism as the result of a fast? 

 Outwardly the subject becomes emaciated, his body weight de- 

 creases, he becomes weak and apathetic and, should the fast proceed 

 long enough, he would probably die in a State of coma. In man it 

 has been demonstrated that the brain retains its activities unimpaired 

 during a fast and that hunger is evident only at the beginning of the 

 ordeal. These facts are substantiated in the populär writings upon 

 fasting and also by an experiment made by us (11) in which the 



