38 ORIGIN OF LOWEST ORGANISMS. 



ration." These experiments were soon repeated by 

 other observers, who, using different fluids, obtained 

 quite opposite results. Thus it became obvious to 

 impartial critics, that whilst the means adopted by 

 M. Pasteur might be adequate to check the processes 

 of fermentation or putrefaction in certain fluids, they 

 were quite powerless to effect this when many other 

 fluids were employed. 



These particular experiments, however, still seem 

 to exercise a very great influence on the minds of many 

 in this country, who are either unaware of, or disbe- 

 lieve in, the possibility of obtaining opposite results. 



The chapter in which M. Pasteur detailed these 

 experiments is thus entitled : "Another very simple 

 method of demonstrating that all the organised products 

 of Infusions (previously heated) oive their origin to the 

 corpuscles which exist suspended in the Atmosphere" 

 Whilst claiming to have already rigorously established 

 the validity of this conclusion by the experiments 

 described in previous chapters, M. Pasteur adds : " If 

 there remained the least doubt on this subject, in the 

 mind of the reader, it would be dissipated by the ex- 

 periments of which I am now about to speak." (p. 66.) 



Sweetened yeast-water, urine, infusions of pear and 

 of beetroot, were placed in flasks with long necks, 

 variously drawn out and bent. The flasks were sub- 

 sequently treated as follows. M. Pasteur says : " I 

 then raise the liquid to the boiling-point for several 

 minutes until steam issues abundantly from the ex- 



