ORIGIN OF LOWEST ORGANISMS. 69 



No. VIII. Hay Infusion remained bright and clear for 

 twelve days. On the thirteenth day a very slight 

 (almost inappreciable) sediment was seen, which scarcely 

 underwent any obvious increase during the next eight 

 days, though on the two following days (twenty-second 

 and twenty-third) the turbidity became most obvious : 

 much sediment was deposited, and the fluid assumed 

 a much lighter colour.* (On the twenty-second day 

 the temperature of the bath was raised to 100 R, for 

 two or three hours.) 



No. IX. Turnip Infusion remained for four days without 

 undergoing any apparent change. Its neck was then 

 accidentally broken at the fourth joint a certain amount 

 of fluid still filling the third joint. In this condition 

 the flask was allowed to remain in the water-bath, and 

 the fluid continued quite unchanged in appearance for 

 five days. It was then boiled \ for three minutes, and 

 the neck of the flask was hermetically sealed whilst the 

 fluid was boiling. The flask being re-immersed in 

 water-bath, the fluid continued quite clear for thirteen 

 days. Its neck was then carefully heated in the spirit- 

 lamp flame till, when red-hot, the rapid inbending 

 of the glass showed that the vacuum was still pre- 

 served. This being ascertained, the flask was, after 

 a few minutes, replaced in the bath. The next day 

 the temperature of the bath was allowed to go up 

 to 100 F. for three or four hours, and in the evening 

 the fluid was observed to be very slightly turbid. In 

 two days more (i.e., after sixteen days in vacuo) the 



* Flask still in my possession, unopened. 



f The vapour had lost all odour of turnip. Some of the fluid 

 which splashed over was found to be still slightly acid. 



