193 



Metabolism of Healthy Man. 



weight per hour during sleep for all the subjects was 1.07 calories. Basing the 

 calculation on the area of body-surface we find that for every square meter of 

 body-surface the average heat production per hour is 35.3 calories, ranging from 

 29.1 calories with A. H. M. to 42.7 calories with H. E. S. 



In table 75 most of the results are of experiments in which the data permitted 

 the computation of the heat production. In some instances only the data for 

 the heat elimination were available. The results for the experiments here 

 reported are in nearly all cases for sleep following rest rather than for work 

 experiments. In a few instances, namely, with J. C. W., A. L. L., E. 0., 

 B. F. D., and J. F. S., the results likewise include the experiments made while 



1 In computing body-surface the formula of Meeh has been used : 12.312 Vbody-weight. 



the subjects were sleeping after muscular work. If only the experiments in 

 which sleep followed rest were included, the values would be somewhat less for 

 these. For example, with B. F. D., who may be said to fairly represent the 

 other subjects, the values for the amount of heat production per hour, per kilo- 

 gram per hour, and per square meter of body-surface per hour would be 70, 1.05, 

 34.7 calories, respectively, values slightly lower than those given in the table. 



Influence of Previous Muscular Activity on Heat Production during Sleep. 



As was pointed out in the preceding paragraph, the influence of previous 

 muscular activity tends to increase somewhat the heat production during sleep. 

 Several of the experiments render possible a comparison of sleep after rest, sleep 

 after moderate work, sleep after severe work, and, in one instance, sleep after 

 very severe work, a comparison which has previously been made for the carbon- 

 dioxide excretion and the oxygen consumption. The results are presented in 

 table 76. Here again it is necessary at times to use values which involve only 

 the heat elimination instead of the heat production. Since the results are the 

 averages in most instances of a number of experiments, they represent with con- 

 siderable accuracy the exact conditions and the differences are particularly well 



