THE BEGINNINGS OF LIFE. 407 



results. The same substance would decompose in the 

 same way on different occasions, if placed under the in- 

 fluence of similar conditions, so that if certain kinds of 

 organisms arose de novo on any occasion during the 

 occurrence of such changes, similar organisms ought 

 also to be produced whenever these changes were re- 

 peated. Therefore, whether the organisms which are 

 undoubtedly to be met with in association with certain 

 fermentations are to be regarded as causes or as conco- 

 mitant results, is a question which can only be settled 

 by having recourse to experiment. If living things are 

 shown to be capable of arising de novo, then the doctrine 

 that fermentations cannot be initiated without the 

 agency of living things must receive its death-blow. 



M. Pasteur did appeal to experiment to support him 

 in maintaining this particular doctrine of fermentation, 

 which, as the reader should not forget, is repugnant to the 

 teachings of many chemists equally eminent with himself. 

 We have endeavoured to show that the experimental 

 evidence on which M. Pasteur relies in support of his 

 doctrine is insufficient and inconclusive nay, more, 

 that many other careful experimenters, who have no 

 theory whatever to support, have failed to get results 

 similar to those which he has recorded. We have, more- 

 over, attempted to explain why his own results cannot 

 fairly receive the interpretation that he has applied to 

 them. Thus, not only has M. Pasteur been unable to 

 establish his point with reference to the nature of the 

 relation existing between organisms and those ferment- 



