252 DR SUTHERLAND SIMPSON ON 
I would take this opportunity of expressing my indebtedness to both for their ready 
consent to pass through this, to healthy young people, somewhat trying ordeal. 
Miss A. B. (age 27, weight 116 lbs., height 5 ft. 7} ins., and of slender build) 
made observations at irregular hours on November 27 and 29, while engaged in her 
ordinary work at the University, to obtain curves on days of activity for comparison, 
and on the 28th took readings every hour, keeping bed from 10.15 p.m. on the 27th 
till 6 a.m. on the 29th, at the same time abstaining from food, “except a glass of 
milk and some crackers between six and seven in the evening.” When examining her 
figures I found that twice there were somewhat sudden elevations in the temperature 
(at 3 p.m. and 6 p.m, fig. 12), which then quickly dropped again, and on writing to 
her to find out the cause of these, her reply was: “. . . I read some, slightly propped up 
in bed. The rises in temperature came at the periods when I was disturbed by callers. 
I tried to keep my room at the same temperature as I had it at night—heat off and 
window open. I remember that during the afternoon I was very restless, even 
when alone.” It is quite evident to me that she had difficulty in restraining her 
muscular movements to the same extent that I did, and this is shown in her 
temperature chart for that day (fig. 12). 
Mr X. Y. (age 27, weight 134 lbs., height 5 ft. 84 ins., and sparely built) also continued 
his experiment for three days. On January 29 and 31, 1910, in his rooms and while 
at work in the laboratory, he made observations every two hours, and on the 30th 
every hour from 5 am. till 10 p.m. Like Miss A. B., he kept bed from 10 p.m. on 
the 29th till 6 a.m. on the 31st, but he had three meals at his usual hours—breakfast 
at 8 a.m., dinner at 1 p.m., and supper at 6.30 p.m. Besides, he was reading most 
of the time, and this implies a fair amount of muscular exertion, since in the recumbent 
posture a book is not easily held in front of one in such a position that it can be read. 
In this experiment, although the curve is distinctly modified when compared with that 
of the day before or the day after (fig. 13), the temperature range is considerably 
greater than in either the case of Miss A. B. or that of the writer. It may be 
mentioned in passing that neither of these (A. B. nor X. Y.) was a good subject for 
this experiment, since both are naturally energetic and somewhat restless individuals. 
In the literature of this subject which I have consulted several temperature charts 
are presented from healthy individuals “resting in bed” during the day, and most show 
a very distinct diurnal variation. For example, in PEmprey’s article on ‘“ Animal 
Heat” in ScHArer’s Text-book of Physiology (vol. i. p. 800), a curve, copied from 
RinceR and Srvarr,* is given which “ shows the daily fluctuations of temperature im a 
boy 12 years old; the thermometer—a non-registering one—was kept in the closed 
axilla throughout the time, and the readings were taken every hour. The boy was in 
good health, and was kept in bed during the observations,” which extended over fifty 
hours. The range for each of the twenty-four hour periods is almost 2° C. (from about 
36° to about 38°). I cannot help thinking that this must have been a particularly 
* RINGER and Stuart, Proc. Roy. Soc., Lond., vol. xxvi., 1877, p. 187. 
