L ANIMALCULA OF INFUSIONS, 



CHAP. III. 



EGGS AND ANIMALS, SEEDS AND PLANTS, EXPOSEI) 

 TO DIFFERENT DEGREES OF HEAT. 



In the month of May, I fiihed up the eggs of 

 frogs, which had a few hours before been depo- 

 fited in the water of ditches. The quantity was 

 divided into equal portions, and each expofed to 

 a different intenfity of heat, in this manner. The 

 eggs were completely immerfed in water, where 

 I had put the ball of a thermoyieter. The velfel 

 was then placed on a flow fire ; and, when the 

 thermometer had attained the requifite height, 

 the eggs were taken out, and each portion put in 

 a veflel of cold water. I had ten veflels, becaufe 

 there were ten portions of eggs that had experi- 

 enced different degrees of heat, as III'', 122*^, 

 133% 144°, I55^ 167% 178% 189°, 2oo% 

 212^. 



The eggs that fuffered 1 1 1*^, 122^, 133*^, pro- 

 duced young, but with fome difference. Ahnofl all 

 thofe at 111° were fertile ; fewer produced at 

 1 2 2°, and the number extremely fmall at 133°. The 

 whole that were expofed to greater heat became 



corrupted. 



