1, ANIMALCULA OF INFUSIONS. 75 



heat ( I ). I took feveral river carp for experi- 

 ment. When the water they were in had been 

 heated to 106'^, they exhibited no fign of uneafi- 

 nefs. At 109°, they began to ftruggle, and died 

 at 116°. Experiments were made on other 

 hfhes, as eels, tench, lampreys, but none could 

 bear fo much heat. Whence, by analogy, thofe 

 inhabiting warm fprings fliould fupport greater 

 heat : and of this the fifhes we have jull mention- 

 ed afford ample evidence (2). 



But of all known animals, reptiles and infefts 

 ftand in greatell dread of cold, and feek heat the 

 moft. The heat of the fun may be called their 

 foul. Then they are full of fcnfation and motion ; 

 and as that luminary is more powerful, fo do 

 their ^ad:ivity, vivacity, and boldnefs increafe. 

 The venomous kinds, as fnakes and fcorpions, are 

 more formidable, and their poifon more danger- 

 ous. But cold produces an oppoiite effed. In- 

 numerable infeds perifh on the approach of win- 

 ter, and moft of both them and reptiles that fur- 

 vive would encounter the fame hazard, if not 

 protedled againft it. In temperate chmates, all 

 feek a fafe retreat when winter comes. Some, as 

 fcorpions, and many fpecies of flies, retire to the 

 rents of walls, or under the tiles of houfes ; 

 others are concealed in the midft of ftones, the 



c lifts 



(i) Haller, Phyfiol, Tom. 2. (2) Ibid. Tom. 4. 



