PASTEUR: LACTIC FERMENTATION 71 



a little acid the carbonate of lime which I have had to 

 add to it. And then it is easy to observe it and to recog- 

 nize it as an organized being, all the individuals of which 

 resemble one another. 



Furthermore, this ferment reproduces itself. Just 

 make, as I did, a clear must containing sugar and chalk: 

 sow there a trace of the deposit from a former fermenta- 

 tion, as small an amount as you wish, and you will see 

 a new fermentation begin. The lactic ferment will 

 multiply, as does the yeast of beer. You will have more 

 of it than you sowed, and with this deposit you will be 

 able to start in different liquids as many lactic fermen- 

 tations of sugar as you wish, provided these liquids are 

 well chosen, for this ferment, being a living creature, has 

 its special requirements and develops well only when it 

 finds within reach all that it needs. 



On the other hand, when this is the case, it accom- 

 plishes with rapidity the transformation over which it 

 presides. "The purity of a ferment, its homogeneity, 

 its free unrestrained development by the aid of food 

 substances well adapted to its individual nature, these 

 are some of the essential conditions for good fermenta- 

 tion." Here we have, let us say, in our turn, a revolu- 

 tionary phrase, one that goes out to meet the enemy, 

 drums beating and fuse lighted. 



There is still more in this short memoir of 15 pages. 

 There is a very exact statement of the good or bad 

 influence, as the case may be, of the acidity or alkalinity 

 of the liquid. The yeast prefers sugared media which 

 are acid; the lactic ferment, neutral sugared media, and 

 it is for that reason we add to the cultures carbonate of 

 lime. There is also a hint, as it were an apparition, 

 of the effect of antiseptics. "The essential oil of onion 

 juice inhibits completely the formation of the yeast 

 of beer: it appears equally harmful to Infusoria. It 



