76 PASTEUR 



an extraordinary power of prolificness. The in- 

 dividual cells, twice as long as they are wide, are 

 so minute that it requires 400 of them, placed 

 end to end, and 800, placed side by side, to 

 measure a millimetre in length, that thirty mil- 

 lion can find space in a square centimetre, and 

 three hundred billion are formed in twenty-four 

 hours upon a square metre of the liquid ! What 

 is the weight of these three hundred billions of 

 cells? One gram, and this gram is capable of 

 transforming ten kilograms of alcohol into 

 vinegar in the space of five days. It follows 

 that a single cell consumes, in the course of one 

 day, a quantity of nourishment equal to two 

 thousand times its own weight. From these 

 fabulous figures one can form some conception 

 of the activity of these infinitely small organ- 

 isms and of their formidable power in the 

 economy of universal life. 



Pasteur discovered that the mycoderm of 

 wine could become ill and that it produced 

 either good or bad vinegar as the case might be. 

 Through proper cultivation he obtained perfect 



