[ 4 79 } 
XXXI. Experiments en the Power that Animals % when placed in 
certain Circumjlances , pojfefs of producing Cold. By Adair 
Crawford, M. D . ; communicated by Sir Jofeph Banks, Bart.. 
P. R. S. 
Read June 14, 1781* 
I N the following paper I fhall lay before the Society the 
reftilt of feme experiments, which I made in the courfe of 
the laft fummer, on the power that animals, when placed in cer- 
tain circumftances, polfefs, of producing cold, having pre~ 
mifed a few remarks on the progreffive improvements which 
have been made in the knowledge of heat in general. 
The opinions of the ancients, refpeCting the nature and pro- 
perties of fire, confifted of bold conjectures, which feem 
rather to have been the offspring of a lively and vigorous ima- 
gination, than of a juft and correCt judgement : their ideas on 
this fubjeCt being evidently derived, not fo much from an accu- 
rate obfervation of facts, as from thofe fentiments of admira- 
tion and awe which many of the phenomena of fire are calcu- 
lated to excite. Thus, this element was fuppofed, on the ori- 
ginal formation of the univerfe, to have afcended to the higheft 
place, and to have occupied the region of the heavens : it was 
conceived to be the principle which firft communicated life and 
activity to the animal kingdom : it was confidered as confti- 
tuting the effence of inferior intellectual beings ; and, by many 
of the ancient nations, it was reverenced as the fupreme Deity. 
Indeed the profound veneration with which the element of 
Vol, LXXI. R r r fir® 
