j - s Influence of Inanition on Metabolism. 



The heat of vaporization of water is taken as 0.592 calorie per gram, and 

 by means of this factor and the weight of water vaporized from the body, the 

 energy absorbed by the water is computed. The weights of water vaporized 

 from the lungs and skin are recorded in columns d and e of table 220, and the 

 energy absorbed in their vaporization is recorded in columns d and e, of table 

 231, the total heat required to vaporize all the water being recorded in 

 column /. 



The total heat elimination for the different days of the experiment is 

 recorded in column g. It is to be noted that these values are not identical 

 with those given elsewhere for the total heat production, and it must be borne 

 in mind that heat elimination, as distinguished from the heat production, is 

 here under discussion. The proportions of the total heat eliminated from the 

 body in the various ways have been computed and recorded in columns h to m 

 inclusive. 



From these data, it may be seen that not far from 75 per cent of the total 

 heat eliminated leaves the body by radiation and conduction; 2.3 per cent is 

 utilized in warming the inspired air; as a rule less than 2 per cent is given 

 up by the excreta; about 10 per cent is required to vaporize the water from 

 the lungs; and 12 per cent is required to vaporize the water from the skin. 



The individual fluctuations from these averages are noticeable chiefly in the 

 heat of urine and feces, which is to be expected from the marked variations in 

 the volume of urine excreted. All the other factors, while varying somewhat, 

 are relatively constant, and the average of these experiments with fasting men 

 at rest shows that 1440 calories are eliminated by radiation and conduction, 

 44 calories are required to warm the inspired air, 22 calories are given off by 

 the urine and feces, 424 calories appear in the water vaporized from the lungs 

 and skin, the total average heat elimination being 1931 calories. 



No noticeable abnormalities are to be observed in the similar data for the 

 experiments with food. 



HEAT PRODUCTION 



In the katabolism of protein, fat, and glycogen during inanition, heat is 

 produced. A comparison of the heat production with the katabolism can not 

 be made by simply measuring the heat lost from the body through radiation, 

 conduction, and vaporization of water. The principles involved in the compu- 

 tation of this production as distinguished from the heat elimination have 

 already been discussed in considerable detail in connection with experiment 

 No. 59 (see p. 46). It is only necessary to call to mind here that changes in 

 body-weight and body temperature are theoretically at least of great importance 

 in determining the heat production as distinguished from the heat elimination. 

 As the fast progresses, the body loses weight. The material lost is cooled from 

 the temperature of the body to the temperature of the calorimeter, but the 



