126 Metabolism of Healthy Man. 



variations in" average body-temperature from day to day. 



While, as is seen from the foregoing discussion, there are considerable fluctu- 

 ations in the body-temperature during 24 hours, it still remains to be shown 

 whether the average daily temperature is or is not relatively constant. The 

 material collected in tables 47 and 48 throws considerable light upon this 

 subject, and a close examination of the data shows that, with the same indi- 

 vidual, even on succeeding days, there may be marked differences in the tem- 

 perature average. Thus, in table 47, with the same subject, H. F., the average 

 temperature on 3 successive days with food ranged from 36.95 C. (98.5 F.) 

 to 37.80 C. (100 F.). With other subjects the variations from day to day 

 are, it is true, much less, amounting to about 0.3 C. (0.5 F.). In table 48, 

 experiments without food, there are certain noticeable variations, particularly 

 in the widely-separated days with J. C. W., in whose case the temperature 

 varied from 36.13 C. (97 F.) to 37.11 C. (98.8 F.), or practically 1 C. 

 (1.8 F.). 



Among the shorter experiments shown in table 49, noticeable variations ap- 

 pear in the results with A. H. M. The average temperature of this subject for 

 the day, which was not, however, a 24-hour day, ranged from 36.30 C. 

 (97.3 F.) to 37.10 C. (98.8 F.). With the two other subjects, A. L. L. 

 and H. R. D., who were in more than one experiment, the temperatures were 

 remarkably constant. 



It is obvious, therefore, that the data in these tables tend to show conclusively 

 that the average temperature of any individual may vary considerably from 

 day to day. Accordingly, if such variations are found with the same individual 

 it is not surprising to find that the average body-temperature, as well as the 

 range, during 24 hours is markedly different for different individuals. Tins 

 is strikingly shown in all the tables here presented. 



The value of the average temperature for 24 hours depends, in part at least, 

 upon the number of observations taken, and when these observations were 

 made, since the higher temperatures are commonly experienced during the 

 daytime. As regards the results computed from the rectal records, there would 

 of course be a tendency for the averages to be too high in the shorter experi- 

 ments, since the observations in those experiments were made usually between 

 9 in the morning and 5 in the afternoon. As regards the clinical averages, it 

 has already been indicated that the larger portion of the clinical temperatures 

 were taken during waking hours and few, if any, were obtained during sleep. 

 This fact would tend to affect in a measure the averages given as obtained 

 from clinical observations, and these averages are undoubtedly somewhat higher 

 than they would be if night observations were included. 



