148 PHYSIOLOGY OF THE BACTERIA. 



A high power shows them divided into a series of 

 shorter rods, scarcely born, not yet mobile at the 

 articulations, which are scarcely indicated." 



2. Micrococcus of a beer, having a particular 

 acidity, distinct from that of beer pique, having 

 an acetic odor. " It consists of grains resembling 

 little spherical points jointed by pairs or in fours 

 square " (Pasteur), etc. 



2. ROLE OF THE BACTERIA IN PUTREFACTION 

 AND NITRIFICATION. 



While in the fermentations which we have just 

 passed rapidly in review, we have always been 

 able to study, at least summarily, the chemical 

 action of the different organisms, we are now 

 about to find ourselves in presence of phenomena 

 far more complex. We will have to consider a 

 great number of these vegetables at work, without 

 its being possible to assign to each its role, or to 

 say what is its function. The agent of the nitric 

 fermentation has not as yet even been seen, and it 

 is only by analogy that we class this nitrification 

 with the true fermentations. 



It is not only because of the obscurity which 

 still exists in regard to a great number of peculiar- 

 ities of these two phenomena, that we have united 

 them in the same study. From the point of view 

 of the circulation upon the surface of our globe 

 of the elements essential to the constitution of 

 organisms, they play an analogous role, although 

 opposite the one to the other. 



