124 Metabolism of Healthy Man. 



supposed to be the normal temperature. It is somewhat difficult to place the 

 exact history of the selection of this mark and it may be looked upon as more 

 or less of a thermometric fetich which has been worshiped by long-continued 

 usage. 



An examination of the results presented in the three foregoing tables leaves 

 no doubt as to three points: (1) that the body-temperature of a given indi- 

 vidual may fluctuate through a considerable range during the 24 hours, and 

 from day to day; (2) that the same individual may have an average body- 

 temperature which varies widely on different days; and (3) that two indi- 

 viduals may differ considerably in regard to their average body-temperature. 



DAILY RANGE AND FLUCTUATION IN RANGE FROM DAY TO DAY. 



Taking these points into consideration it is obviously erroneous to assume 

 that there is a normal body-temperature to which all body-temperature measure- 

 ments can be referred. Particularly is this the case when it is considered that 

 it is common, at least among laymen, to suppose that a temperature above 

 98.6 F. indicates a febrile condition. It is a well-known fact, however, and 

 familiar to all clinicians, that many persons, otherwise in perfectly normal 

 health, may show temperatures considerably higher than any of those recorded 

 here in these observations and still give no indications of a pathological lesion. 

 It will be profitable to examine more in detail the fluctuations in individual 

 temperatures, and the differences between individuals as shown in the data 

 presented. 



For an adequate treatment of this subject, more elaborate observations should 

 be recorded than were deemed practicable in this discussion. With the elec- 

 trical-resistance thermometer employed in these experiments, observations were 

 taken every 4 minutes, and consequently more or less continuous curves can 

 be drawn indicating the true temperature fluctuations. Curves of this nature 

 have been prepared in an elaborate discussion in an earlier publication. 1 In 

 tables 47 and 48 are recorded only the minimum and maximum temperatures, 

 and the time of day at which each was observed. 



With regard to the range of temperature that can be experienced on any 

 given day the data shown in table 47 for experiments with food may first be 

 examined. If we consider the 2 days with the first subject, J. C. W., we find 

 that the range in temperature varied from 1.27 C. (2.29 F.) on the first 

 day to 0.93 C. (1.67 F.) on the second day. Similar variations in fluctua- 

 tions from day to day may be observed with other subjects. With H. F., for 

 example, on November 10-11, the range was 0.46 C. (0.83 F.), and on the 

 next day, 1.64 C. (2.95 F.). On the other hand, with one subject, H. L. K., 

 the range was practically identical for 4 consecutive days, varying only from 

 1.08 C. (1.94 F.) to 1.27 C. (2.29 F.). On the whole, however, it is clear 



1 Benedict and Snell, loc. cit. 



