THEORY OF FERMENTATION 333 



taneous fermentation will take place in the deposit in the 

 course of a few days, although no germs of ferment have 

 been added. A living, organized ferment, of the vibrionic 

 type, filiform, with tortuous motions, and often of im- 

 mense length, forms spontaneously by the development of 

 some germs derived in some way from the inevitable par- 

 ticles of dust floating in the air or resting on the surface 

 of the vessels or material which we employ. The germs 

 of the vibrios concerned in putrefaction are diffused around 

 us on every side, and, in all probability, it is one or more 

 of these germs that develop in the medium in question. 

 In this way they effect the decomposition of the tartrate, 

 from which they must necessarily obtain the carbon of their 

 food without which they cannot exist, while the nitrogen 

 is furnished by the ammonia of the ammoniacal salt, the 

 mineral principles by the phosphate of potassium and mag- 

 nesium, and the sulphur by the sulphate of ammonia. How 

 strange to see organization, life, and motion originating 

 under such conditions ! Stranger still to think that this 

 organization, life, and motion are effected without the par- 

 ticipation of free oxygen. Once the germ gets a primary 

 impulse on its living career by access of oxygen, it goes 

 on reproducing indefinitely, absolutely without atmospheric 

 air. Here then we have a fact which it is important to 

 establish beyond the possibility of doubt, that we may 

 prove that yeast is not the only organized ferment able 

 to live and multiply when out of the influence of free 

 oxygen. 



Into a flask, like that represented in FIG. 9, of 2.5 litres 

 (about four pints) in capacity, we put: 



Pure, crystallized, neutral tartrate of lime.... 100 grammes 



Phosphate of ammonia i " 



magnesium x " 



potassium as " 



Sulphateof ammonia 0.5 " 



(i gramme = 15.43 grains) 



To this we added pure distilled water, so as entirely 

 to fill the flask. 



In order to expel all the air dissolved in the water and 

 adhering to the solid substances, we first placed our flask 



