32 " THE GERM THEORY OF DISEASE. 



different forms, which remained constant. I use this simply 

 as an illustration of the plan of what was known as fractional 

 cultivations. The same was done with the lactic acid fer- 

 mentation, and its characteristic plant isolated and established. 

 In time and by this process several others have been success- 

 fully isolated and established, until all of the processes here- 

 tofore known as fermentations have been certainly connected 

 with living organisms, without which none of them can succeed. 



Pasteur, after working out vinous and acetic fermentations, 

 and that peculiar fermentation which destroys, in its turn, 

 the vinegar, has followed up the process of the complete 

 return of the fruit \o the primitive inorganic state. 



After the fermentation of the vinegar, Pasteur next ex- 

 amined the putrid fermentations, or decompositions, as they 

 are usually called. The principal agents in these he found 

 to be certain very active bodies which he called vibrios, and 

 which multiply with remarkable rapidity in the depths of the 

 mass, as much as possible apart from oxygen. This charac- 

 teristic position serves to distinguish them from the ordinary 

 bacteria, which require oxygen for their growth and are found 

 near the surface. 9 



These vibrios of Pasteur are the proper authorities which 

 administer upon the ruined estates of dead bodies, animal and 

 vegetable. 



Countless swarms of bacteria may assist them, by their 

 presence near the surface, by fixing any oxygen which would 

 otherwise be absorbed by the fluid and hinder the work of 

 the vibrios, which work without free oxygen. Pasteur has 

 grown these vibrios in flasks, from which every particle of 

 free oxygen has been removed, and found them to be the 

 true agents of decomposition. 



His fluid for this purpose was prepared by placing in a 

 three-liter flask of water the following salts : 



