64 A'NIMALCULA OF INFUSIONS, L 



Among the germs producing infufion animalcu- 

 la, there is one fpecies that does not perifh at boil- 

 ing heat, whence the fmallefh animalcula originate, 

 or, as we have termed them, of the lowed clafs. 

 The refemblance in minutenefs of fuch animalcula, 

 and thofe originating at freezing, made me fuf- 

 pe6t, that the germs refilling boiling might be the 

 fame with thofe expanding at freezing. Rigo- 

 rous experiment was neceffary to afcertain whe- 

 ther it was aftually fo. While feveral new infu- 

 fions were buried in fnow, others hermetically 

 fealed were expofed to boiling heat ; and I examin- 

 ed both at a proper time, but I never could dif- 

 cover any fenfible difference in the figure, fize, 

 organization, or motions of the refpeftive animal- 

 cula ; whence I think there is fufficient reafon to 

 conclude they are identically the fame fpecies. 

 The identity of the animalcula eflabliflies the 

 identity of the germs. Two moft fmgular pro- 

 ■pertles, therefore, exifl in thefe minute animated 

 ■beings ; one the power of refilling the heat of 

 -boiling water ; the other the peculiarity of ori- 

 ginating at freezing, 

 r 



CHAP. 



