274 Influence of Inanition on Metabolism. 



Nitrogen Metabolism Experiments. 



Second only in importance to the study of the effect of inanition on meta- 

 bolism is the study of the recovery of material lost during fasting. In the 

 original plan under which the fasting experiments were projected a study of 

 the recovery after fasting was contemplated. It was soon seen that such 

 experiments were impracticable because as a rule, the subjects were unable 

 to consume large amounts of food on the day immediately following a fast. 

 It became necessary to modify materially the original plan and continue the 

 food experiments in the respiration chamber for only a few days and with a 

 small ration (hardly more than maintenance). None of the food experiments 

 reported above were therefore of more than 3 days' duration. But although it 

 was impossible to continue the experiments in the respiration calorimeter and 

 thus obtain the complete balance of income and outgo, the plan was adopted 

 of weighing and sampling all the food of the subject and noting the amounts 

 of nitrogen, phosphorus, and sulphur in the food, feces, and urine of each day. 

 This was done in the hope of obtaining much new information on the recoup- 

 ment after prolonged inanition, since the recorded observations on the effect on 

 metabolism of the ingestion of food after a period of inanition are extremely 

 few. 



Arrangements were made therefore to weigh and analyze all the food eaten 

 by the subject S. A. B. from March 14, the first day after metabolism experi- 

 ment No. 76, until the beginning of metabolism experiment No. 77 and from 

 the first day after experiment No. 77, i. e., April 12, until April 25, when he 

 left Middletown, and hence was beyond our control. 



During these periods all the food and the urine and feces were sampled and 

 analyzed. The data thus obtained constitute a study of the complete intake 

 aud output of nitrogenous material for a period of 53 days, i. e., from the 

 first day of fasting experiment No. 75 until April 25. The intake and output 

 of phosphorus were likewise studied and hence the gains or losses of this 

 element can be determined. In a measure the same is true of the sulphur 

 balance. Furthermore, since the heat of combustion of the food eaten was 

 determined each day, much valuable information regarding the energy con- 

 sumption was secured. 



Diet. With the exception of experiment No. 77, each fast made by the 

 subject S. A. B. was followed by an experiment in the respiration chamber 

 in which food was given (experiments Nos. 72, 74, and 76). The change 

 from fasting to food metabolism, therefore, was studied while the subject was 

 in the chamber. Usually the quantities of food that the subject wished to take 

 on the first day after the fasting period were small, barely more than enough 

 for maintenance. 



