^OO AKIMALCULA OF INFUSIONS. I» 



hour to two hours, that thefe animalcula, I fay, or 

 part of them, may come from the external air, 

 from that in the veffels or the feeds attached to 

 their fides, or from all three ? This conclufion 

 feems the more probable concerning the higher 

 clafles. Indeed, if we fuppofe that they or their 

 feeds lodged in the infufed matter, there is np 

 reafon why they Ihould not appear in veffels her- 

 inetically fealed, and expofed to the heat of boil- 

 ing water, if that degree was not prejudicial tq 

 their appearance. You have proved that they 

 are ftill feen in fealed velTels of infufions, which 

 have not been expofed to heat. The higher 

 cl'afSj therefor^, did not pre-exift in the infufed 

 mitter : But I do not thence mean to infmuate, 

 that they ax their germs could not pre-exifl in it, 

 for animal and vegetable fubftances are probably 

 covered with them. I only mean, that thefe ani? 

 jualcula, or their germs, are probably deftroyed 

 by boiling the fubftances where they are lodged. 

 Are you not furprifed, my dear friend, that I do 

 jaot fay certainly deftroyed ? But I dare not make 

 fuch a pofitive aflertion concerning beings fo littl^ 

 known. Is it not poffible, that the heat of boil- 

 ing water, or any other of equal or even greater 

 degree, produces no effed but deficcation of ani- 

 jnalcula or their germs, and thus reduces them to 

 a ftate analogous to that of pennated polypi's 

 eggs, which may be kept dry feveral months, as 



