I, ANIMALCULA OF INFUSIONS. I^ 



neck of the veffel was drawn out at the lamp al- 

 •moft to a capillary tube : the fmalleft part was 

 then inftantaneoufly fealed, fo that the internal 

 air could fufFer no alteration, as was evident from 

 no hiiTing being heard on breaking the veffel. 



After afcertaining that the included air was of 

 the fame denfity as the atmofpherical, it was ne- 

 ceffary, before expofmg the veflels to heat, to in- 

 veftigate, whether fimple inclufion of the feeds 

 would obftruft the production of animalcula ; 

 Was it fo, it could be afcribed neither to heat 

 nor air, but the clofenefs of the velfels alone. 

 Other experiments had rendered me cautious 

 here(i). They had taught me, i. Infufion ani^ 

 nialcula are not produced in vefllls hermetically 

 fealed unlefs the veifels are capacious ; 2. They 

 are not always produced ; 3. They are never fo 

 numerous as in open veifels. I now felt the ne- 

 .celTity of fuch circ^imfpe£tion, and although it 

 was ufed, two fubflances, kidney beans and peafe^ 

 ceafed to produce animalcula. The other nine 

 feeds produced a moderate number. To thefe 

 nine only, I confined myfelf, and fubjefted each 

 to heat in the following manner. Nine veifels, 

 hermetically fealed, containing feeds, were im- 

 merfed in boiling water half a minute ; other 

 nine, a minute; nine more, a minute and a half ^ 

 and nine, two minutes. Thus I had thirty-fix iiv 



fufionsj 



(1) D'uTert. Cip, 19, 



