FERMENTATION. 57 



the cause of the phenomena of fermentation made a 

 forcible impression upon all thinking minds. ' In 

 these infinitely small organisms,' M. Dumas said one 

 day to M. Pasteur before the Academy of Sciences, 

 ' you have discovered a third kingdom the kingdom 

 to which those organisms belong which, with all the 

 prerogatives of animal life, do not require air for their 

 existence, and which find the heat that is necessary 

 for them in the chemical decompositions which they 

 set up around them.' 



The work of Pasteur, demonstrating that fermen- 

 tation was always dependent on the life of a micro- 

 scopic organism, continued without interruption. One 

 of the most remarkable of his researches is that 

 which relates to the fermentation of the tartrate of 

 lime. The demonstration of life and of fermentation 

 without free oxygen is in this paper carried to 

 the utmost limits of experimental rigour and pre- 

 cision. 



III. 



But there is still another class of chemical pheno- 

 mena where the life without air of microscopic or- 

 ganisms is fully shown. Pasteur proved that in the 

 special fermentation which bears the name of putre- 

 faction the primum movens of the putrefaction resides 

 in microscopic vibrios of absolutely the same order 

 as those which compose the butyric ferment. The 



