282 



STUJ)II-:S ON FERMEXTATIOX, 



small matter tliat one more ferment should be placed in a list 

 of exceptions to the generality of living beings, for whom 

 there is a rigid law in their vital economy which requires for 

 continued life a continuous respiration, a continuous supply 

 of free oxygen. Wh)', for instance, has Dr. Brefeld omitted 

 the facts bearing on the life of the vibrios of butyric fer- 

 mentation ? Doubtless he thought we were equally mistaken 

 in these : a few actual experiments would have put him 

 right. 



These remarks on the criticisms of Dr. Brefeld are also 

 applicable to certain observations of M. Moritz Traube's, 

 although, as regards the principal object of Dr. Brefeld's 

 attack, we are indebted to M. Traube for our defence. This 

 gentleman maintained the exactness of our results before the 

 Chemical Society of Berlin, proving by fresh experiments that 

 yeast is able to live and multiply without the intervention of 

 oxygen. " My researches," he said, " confirm in an indis- 

 putable manner M. Pasteur's assertion that the multiplication 

 of yeast can take place in media which contain no trace of 

 free oxygen. . . . M. Brefeld's assertion to the contrary 

 is erroneous.'^ But, immediately afterwards, M. Traube adds : 

 " Have we here a confirmation of Pasteur's theory ? By no 

 means. The results of my experiments demonstrate, on the 

 contrary, that this theor}^ has no sure foundation." What 

 were these results ? Whilst proving that yeast could live 

 without air, M. Traube, as we ourselves did, found that it had 

 great difl&culty in living under these conditions ; indeed he 

 never succeeded in obtaining more than the first stages of 

 true fermentation. This was doubtless for the two following 

 reasons — first, in consequence of the accidental production of 

 secondary and diseased fermentations, which frequently prevent 

 the propagation of alcoholic ferment ; and," secondly, in conse- 

 quence of the original exhausted condition of the yeast 

 employed. As long ago as 1861 we pointed out the slowness 

 and difficulty of the vital action of yeast when deprived of air, 

 and a little way back, in the preceding paragraph, we have 



