4 
Dr. Bell on the Generation of 
a turgefcence of the veins, and an univerfal red- 
nefs of the furface of the body, took place ; we 
are compelled to refufe credit to the affertion, 
even of Dr. Fordyce, that there was no evapora¬ 
tion. The evaporation mufi: have been great, and 
would diminifh the effect of the external heat by 
furrounding the furface with a cool atmofphere, 
from its temperature fit for the abforption of heat, 
and from its rarity, unfit for the ready tranfmif- 
fion of it into the body. 
III. But another very powerful caufe of the 
body’s having preferved its temperature in the 
given fituation, remains to be noticed ; which is, 
<The fuccefflve afflux of blood to the furface, of a tem¬ 
perature inferior to that of the furrounding air .—By 
this means, the fmall quantity of heat which 
penetrated the fkin would be immediately carried 
off, and transferred throughout the body: and it 
would have required the fpace of many hours, 
before the whole mafs could have received any 
confiderable increafe of heat *. 
It has been adduced, in proof of the exiftence 
of the power of the living body to generate cold, 
that frogs, lizards, and other animals of the fame 
• It may here be remarked, that the two Iaft mentioned 
caufes aft more powerfully in moderating the heat of the 
external air, according to the neceffity there is for their 
aftion: for both the evaporation from the furface, and the 
velocity of the circulation of the blood, are in proportion 
to the degree of heat applied. 
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