12 
The observations were invariably taken while actually 
rowing or climbing. 
These numbers are, in the main in accordance with those 
of Dr. Forel, and shew that a slight increase took place in 
my body-temperature during physical exertion. This in- 
crease was decidedly marked during the first half hour while 
rowing, and the first one and a-half hours while climbing, 
after which times a diminution of temperature took place, 
the final temperature being in no case, however, so low as 
the initial temperature. 
Dr. Anderson, (loc. cit.) has attempted to explain the 
varying results of different observers by supposing that in 
some men the heat transformed into motion, and spent in 
doing work is restored by quick oxidation of material with- 
in the organism, while in the case of others whose power of 
oxidation is slower, no such equilibrium is maintained, and 
a decrease in body temperature consequently ensues. 
Looked at in this light the above numbers seem to show 
that during the earlier phases of physical exertion oxidation 
was more than sufficient to restore heat spent in doing work, 
but that as the work was continued and grew harder the 
excess of heat was gradually encroached upon. In the paper 
already cited from Nature (vol xii, p. 132) the abstractor 
shews that if body-temperature be taken as the exponent of 
internal work, then a greater increase ought to be observed 
during extra muscular work if unaccompanied by external 
work than if so accompanied. The results which I have 
obtained during canoeing bear out this theory. The follow- 
ing were the numbers : — - 
Experiment IY. 
Initial temperature 9S°*3 F. 
After 20 minutes hard paddling 99° # 4 
After 30 „ „ „ 99°'4 
The external work .done in propelling a light canoe 
through the water must be less than that needed for the 
