$12 ANIMALCULA OF INFUSIONS. - I* 



which appeared 1765. In page 117, you rea- 

 foil plaufibly, without fufpefliing that experiment 

 made by yourfelf would one day be adverf^ to it. 

 You undertake to refute the author of Lett res a 

 un Jmericain, who thinks, without any direct 

 proof, that heat of great intenfity is requifite for 

 the produfiion of certain animalcula, and exprefs 

 yourfelf thus, ' It is enough that we view the 

 ' fine and delicate texture compofmg the inter- 

 ^ nal mechanifm of the animal, which may be 



* confidered an aifemblage of the llendereft filk- 



* en filaments, and we fhall eafily be fenfible 

 .'' what ravages and deilruftion an irregular intef- 

 ' tine heat would caufe among them : If we fee 



* this heat, jn warming the fmid, kill adult and 

 " vigorous animalcula, fo much the more will it 

 ' aifeft them in their integuments while yet weak 



* and tender.' Nature itfelf evinces, that it is 

 -the germs or integuments of animals which fup- 

 port the heat of boiling water, whereas the ani- 

 malcula them^felves perifh at 106** and 108°. 

 This inilance, like many others, proves how the 

 moft fpecious arguments may becom.e deceitful 

 in philofophy, and that vi^e fhould diflrufl con- 

 clufions merely rational in fubjefts of natural hif- 

 tory and philofophy. Thirty years ago, if one 

 had alked the moil acute philofopher, or the 

 moH cxoert anatomifl. Whether he conceived 

 that an animal could be multiplied by cutting it 



in 



