xxxii THE BEGINNINGS OF II FE. 



the two following days (twenty-second and twenty-third) the 

 turbidity became most obvious : much sediment was depo- 

 sited, and the fluid assumed a much lighter colour^. (On 

 the twenty-second day the temperature of the bath was raised 

 to 1 00° Fahr,, for two or three hours.) 



No. IX. Turnip Infusion remained for four days with- 

 out 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 con- 

 tinued 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 a 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 inbend- 

 ing of the glass showed that the vacuum was still preserved. 

 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 loc F. for three or four hours, 

 and in the evening the fluid was observed to be very slightly 

 turbid. In two days more (z>., after sixteen days in vacuo) the 

 turbidity was well marked, and when the fluid was examined 

 microscopically it was found to contain an abundance of very 

 languid Bacteria and Vibriones. On opening the flask 

 there was an outrush of very foetid gas, and the reaction of 

 the fluid was acid^. 



^ Flask still in my possession, unopened, 



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

 splashed over was found to be still slightly acid. 



^ This experiment is very interesting in two or three respects. A 

 neck of half the usual length — with only four bendings — sufficed to pre- 

 serve the fluid for several days ; and when this fluid (which had been in 

 the bent-neck apparatus for nine days) was sealed up in the same flask 

 during ebullition, it remained in vacuo for thirteen days without under- 



