]48 EFFECTS OF HEAT ON ANIMALS. 



Berger, of Geneva, who shared the labour, and assisted 

 me with his advice. 



Sect. I. Of the Degree of Heat that Animals can endure. 

 The limits of It i s scarcely possible to investigate the effects produced 

 this faculty not on animals by heat, and the faculty they have of resisting 

 determinable . J . , , ,. . ~ 



•with precision. it, without being prompted to ask, what are the limits of 



this faculty? in other words, what is the greatest degree of 

 heat they can support, without being deprived of life ? — 

 This question however is insusceptible of a precise answer. 

 The time must The effects of heat being in the ratio of the duration as well 

 be considr ed ag } n t e nsity of its action, it is not till a very long time has 

 intensity. expired, that we can consider an animal as having under- 

 gone all the influence of the heat to which it has been ex- 

 The tempera- posed, and conclude it to be capable of resisting it. We 

 ture subject to cannot ijk ew i se prevent this temperature, on the one hand, 

 from experiencing considerable variations, which hinder its 

 and the animal being ascertained with precision ; and the animal, on the 

 affected by va- ther, from being subjected to the influence of foreign cir- 

 stances. cumstances, by which the effects of the heat will be modi- 



fied. 

 Conclusions The author here relates various experiments made on se- 



fiom the au- veral animals, from which he draws the following conclu- 

 thor's experi- 

 ments. slons - 



From these experiments it follows, as might have been 



presumed, that all animals are not equally affected by heat, 

 and that the faculty of resisting it is not the same in every 

 species. We cannot therefore derive from them any gene- 

 ral and precise conclusion with respect to the measure of 

 Small animals this faculty. These experiments however are sufficient to 



killed by a heat snew that most animals, at least those of a small size, sink 

 of!34 g orl44°. ' * ' ' 



under a temperature of 144°, or even 134°, after a certain 



space of time, which is generally pretty short. They shew 



too, that the progress of the symptoms is more rapid, and 



the arrival of death more speedy, in proportion as the heat 



is greater. 



The larger the The size of animals appears to have a marked influence 



ammal the bet- on ^g speediness of the effects of heat. The ass supported 

 ter it resist* r rr 



heat. them much longer than the cat, the dog, the rabbit, and 



the guinea-pig; and these longer than the mouse. The 



magpie 



