154 PASTEUR 



Each fermentation is the product of the devel- 

 opment of a special microbe. 



"The second may be formulated: Each in- 

 fectious disease (or at least those which have 

 been studied by M. Pasteur or his immediate 

 disciples) is produced by the development of 

 some special microbe within the organism. 



"The third may be expressed as follows : The 

 microbe of an infectious disease, if cultivated 

 under certain specified conditions, becomes at- 

 tenuated in respect to its harmful qualities; it 

 has been converted from a virus into a vaccine. 



"As practical consequences of the first dis- 

 covery, M. Pasteur has given rules for the man- 

 ufacture of vinegar and beer, and he has shown 

 how beer and wine may be preserved from those 

 secondary fermentations which turn them sour, 

 cause I'amer, la graisse, la pousse, and prevent 

 their transportation and often even their pres- 

 ervation on the spot where they are produced. 



"As practical consequences of the second dis- 

 covery, M. Pasteur has prescribed the rules to 

 be followed in order to protect our flocks and 



