258 DR SUTHERLAND SIMPSON ON 
while that of the mouth and of the rectum rises. The mouth and axilla curves separate 
at that point and do not meet again until the following morning. On the resting days, 
when the subject remained in bed, the figures for the mouth and axilla are practically 
identical at every observation, and the two curves run fairly parallel with that of the 
rectum. In the case of a patient confined to bed then, are the mouth and axillary 
temperatures as unreliable as they are held to be? The temperature of the mouth 
particularly, and also of the axilla, is affected by the temperature of the surrounding air, 
rising and falling with it, and when this is fairly regular, as it usually is in a sleeping- 
room, the parallelism between the mouth and axillary curves and that of the rectum 
appears to be on the whole pretty constant. With the subject outside in the open air 
and exposed to atmospheric changes, the case, of course, is different. 
The above remarks, it must be remembered, are meant to apply only to the case of 
the person who was the subject of this experiment. There may be, and there probably 
are, great variations amongst different individuals in this relation. For example, in a 
sparely built person the walls of the buccal chamber will be thinner, and it will be more — 
ditheult to convert the axilla into a closed cavity than in a stout individual, so that the — 
temperature of both localities will be more susceptible to changes in the surrounding 
air in the former than in the latter. 
With regard to the question of individual differences in the response of the mouth and 
skin temperatures to muscular activity I was interested to find, in reading over the report 
of LinpHARD,” that his results were different from mine. He says: ‘‘ With regard to the 
mouth temperature, its relation to the work of the muscles is quite inconstant. As a 
rule it does not rise during work. On working indoors, it is almost constant; on work- 
ing in the open air it always falls, but in a single case | have found it so much raised 
while staying indoors soon after working in the open air, that the rise must without 
doubt be ascribed to the work. On the other hand, I have seen that even energetic 
exercise indoors was not able to prevent the mouth temperature, raised by the meal, — 
from falling. . . . For the temperature of the skin pretty much the same holds good 
as for the mouth temperature; as a rule I have not been able to notice any rise 
occasioned by muscular work.” 
In order to test this matter further in the case of my own temperature | have lately 
made a few experiments, the results of which are given in tabular form below. These 
observations were made in September, when the outside temperature was fairly high, 
and again in November, when the weather was colder. The readings were taken first 
in the recumbent posture just before getting out of bedt in the morning, then in the 
sitting position half an hour later, after dressing but before breakfast, again after break-_ 
fast, and finally immediately after a walk of about three-quarters of a mile up a pretty 
steep hill and then two flights of stairs to a room in the laboratory. The same clothing 
was worn and the same muscular energy expended on each day in approximately the _ 
* LINDHARD, loc. cit., p. 18. 
+ The bed was outside on the verandah. 
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