J 46 EFFECTS OF HEAT ON ANIMALS. 



losophers, to make fresh researches into the influence, that 

 high temperatures have on the animal economy. Their ex- 

 periments are too well known, to be repeated here : it is 

 Supported a sufficient to say, that they could support for several minutes, 



heat above 2 12* w jthout being too seriously inconvenienced, a heat superior 



some time. o j ■> i 



to that of boiling water ; and that they confirmed, in a more 

 accurate manner than had before been done, the facalty 

 man enjoys of keeping himself at a nearly constant tem- 

 perature, though placed in an atmosphere of which the 



Ascribed it to heat is far superior to his own. These gentlemen, struck 

 ap ra ion, -with the copious perspiration, that was formed when they 

 were exposed to the heat ; observing too, that the moment 

 when this perspiration shewed itself was distinguished by a 

 diminution of the painful sensation they experienced from 

 the heat; were led to suppose, that the evaporation from 

 the surface of the body contributed greatly to this unifor- 



which appeared mity of temperature. Some experiments they made on the 



to keep liquids heating of liquids exposed in open vessels, and introduced 



under similar . . 



circumstances into the heated room, confirmed them in this opinion. In 



from boiling. f act t^gg liquids fc e pt themselves uniformly at a temperature 



below that of the surrounding medium, and could not be 



brought to boil, till they were covered by a stratum of 



Thev supposed melted wax, which prevented the evaporation. Neverthe- 



however some less these gentlemen did not think, that evaporation of the 



perspirable matter was the sole cause of the uniformity of 



temperature, which they had observed in themselves, though 



exposed to a heat so much higher. 



Dr. Dobson At the same time Dr. Dobson, of Liverpool, made some 



made similar experiments in the hospital there, which were nearly similar 



and attended with similar results. 

 J. Hunter ap. About the same period too, or a little after, Mr. John 

 P a^sof e th t0 Hunter published some inquiries he had made respecting the 

 body, heat of animals. Most of these related to their faculty of 



enduring cold ; some however respected their capacity for 

 resisting heat. The latter were not made on the whole body 

 of men or animals subjected to the experiment, but on 

 and imagined particular parts merely ; and Mr. Hunter thought he per- 

 ils effects were ceived, that this faculty, though it could not be considered 



resisted better , , , , . , „ , •, .-. ,, . r 



than those of as absolute, was more decidedly marked than that ot re- 

 coid - sisting cold. 



3 Whin 



