64 LOUIS PASTEUK. 



to an assemblage of anaerobic and aerobic germs of 

 those same germs which were mixed up in the original 

 primitive organic substances. 



Though a collection of germs becomes again in its 

 turn a collection of organic matter, subject to the 

 double action of the phenomena of putrefaction and 

 of combustion, there need be no anxiety as to their 

 ultimate destruction ; in the final analysis they repre- 

 sent life under its eternal form, for life is the germ, 

 and the germ is life. 



Thus in the destruction of that which has lived, 

 all reduces itself to the simultaneous action of these 

 three great natural phenomena fermentation, putre- 

 faction, and slow combustion. A living organism 

 dies animal, or plant, or the remains of one or the 

 other. It is exposed to the contact of the air. To the 

 life which has quitted it succeeds life under other 

 forms. In the superficial parts, which the air can 

 reach, the germs of the infinitely small aerobies hatch 

 and multiply themselves. The carbon, the hydrogen, 

 and the nitrogen of the organic matters are trans- 

 formed by the oxygen of the air, and under the in- 

 fluence of the life of these aerobies, into carbonic 

 acid, vapour of water, and ammonia gas. As long as 

 organic matter and air are present, these combustions 

 will continue. While these superficial combustions 

 are going on, fermentation and putrefaction are doing 



