284 STUDIES ox FETIMENTATIOX. 



^ IV. — Fermentation of Dkxtro-Taktrate of Lime.* 



Tartrate of lime, in spite of its insolubility in water, is 

 capable of complete fermentation in a mineral medium. 



If we put some pure tartrate of lime, in tbe form of a 

 granulated, crystalline powder, into pure water, together with 

 some sulphate of ammonia and phosphates of potassium and 

 magnesium, in very small proportions, a spontaneous fermenta- 

 tion will take place in the deposit in the course of a few days, 

 although no g^erms of ferment have been added. A living:, 

 organized ferment, of the vibrionic type, filiform, with tortuous 

 motions, and often of immense length, forms spontaneously by 

 the development of some germs derived in some way from the 

 inevitable particles of dust floating in the air or resting on the 

 surface of the vessels or materials 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 fur- 

 nished by the ammonia of the ammoniacal salt, the mineral 

 principles by the phosphate of potassium and magnesium, and 

 the sulphur by the sulphate of ammonia. How strange to see 

 organization, life, and motion originating under such con- 

 ditions ! Stranger still to think that this organization, life, 

 and motion are effected without the participation of free 

 oxygen. Once the germ gets a primar}'^ 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. 



• See Pasteur, Comptes rendus de V Academie dts Sciences, t. Ivi. p. 416. 



