XXX VI THE BEGINNINGS OF LIFE. 



Vibrio could be detected, and the fluid was still quite 

 odourless\ 



No. XIX. K'eutral Turnip Infusion + \ gr. of Cheese, 



showed no perceptible change in twenty-four hours, though 

 in thirty-six hours there was a well-marked pellicle on the 

 surface. When the neck of the flask was broken after 

 seventy-two hours, the fluid was found to be very foetid, 

 whilst its re-action had become slightly acid. Portions of the 

 pellicle were found to be made up by aggregations of 

 Bacteria, Vibriones, and an abundance oi Lepiothrix filaments. 

 The Bacteria all exhibited very languid movements. 



e. Fluid (in vacuo) in a Flask which had been Sealed during 



Ebullition. 



No. XX. Simple Turnip Infusion in twenty-four 



hours showed a very slight amount of turbidity \ in thirty-six 



hours this had increased, and in forty-eight hours there were 



multitudes of curdy flocculi floating in a tolerably clear fluid. 



The flask was opened after seventy-two hours, when there 



seemed to be only a very slight inrush of air. The odour of 



the fluid was somewhat foetid, and its re-action was acid. 



There were multitudes of Bacteria and Vibriones, partly 



separate and partly aggregated (constituting the flocculi 



above mentioned). The separate Bacteria exhibited only 



very languid movements. 



^ This again is a most instructive experiment when compared with 

 Nos. XVI. and XX., in which portions of the same infusion were 

 employed. The results in No. IX. would lead us to believe that a 

 vegetable infusion which does not ferment, does, nevertheless, undergo 

 some changes in molecular composition, and this notion seems to derive 

 confirmation from the present experiment. Some of the same solution 

 which has been kept for a time (twelve days) from contact with atmo- 

 spheric particles, subsequently, even when fully exposed to the air, 

 undergoes no apparent change fo.r six days, and then, instead of becom- 

 ing filled with Bacteria, swarms only with Torulce. Yet the infusion in 

 this condition was perfectly capable of nourishing Bacteria, as I subse- 

 quently proved by inoculating it. Why then was it not inoculated by 

 the living Bacteria, with which the air is thought by some to be teeming ? 



