t6 ANIMALCULA OF INFUSIONS. |, 



fufions, the feeds in which were expofed to the 

 heat of boiling water. To difcover the proper 

 period for examining the fealed veflels, fimilar 

 infufions were at the fame time made in open 

 veff^ls ; and, when animalcula abounded there, 

 thofe fealed up were vifited. In eleven days, the 

 nine open infufions being full of animalcula, it 

 feemed fit to examine the others. On breaking the 

 firft hermetic feal, ? faint hifling was heard, not 

 unlike that mentioned above. Then it did oc- 

 cur to me that heat had truly injured the elafti- 

 city of the internal air, and excited me to ob- 

 ferve, v/ith the utmoll attention, what happened 

 on breaking the feal. The hifiing was obvious 

 an all ; but I foon difcovered it arofe from an op- 

 pofite caufe, namely, encreafed elafticity of the 

 air. In the firfl place, the flame of a candle was 

 driven from the orifice; fecondly, on juft touch- 

 ing the fealed part with a file, it tv/ice fprung 

 more than a fpan from the veflel ; in the third 

 place, on maldng the infufion flow towards the 

 feal, and then breaking i' the infufion .violently 

 fpouted out ; fourthly, the feal being broken 

 under water, inftead of running into the veflel, 

 the water was forced away. Reflecting on the 

 nature of macerating . fubfl:ances, I faw it could 

 not be otherwife. Vegetable feeds are well 

 known to contain a great quantity of air. Dur- 

 ing 



