270 STUDIES ON FERMENTATION. 



In short, fermentation is a very general phenomenon. It is 

 life without air, or life without free oxygen, or, more generally 

 still, it is the result of a chemical process accomplished on a 

 fermentable substance, i.e. a substance capable of producing heat 

 by its decomposition, in which process the entire heat used up 

 is derived from a part of the heat that the decomposition of the 

 fermentable substance sets free. The class of fermentations, 

 properly so called, is, however, restricted by the small number 

 of substances capable of decomposing with the production of 

 heat, and at the same time of serving for the nourishment of 

 lower forms of life, when deprived of the presence and action of 

 air. This, again, is a consequence of our theory, which is well 

 worthy of notice. 



The facts that we have just mentioned in reference to the 

 formation of alcohol and carbonic acid in the substance of ripe 

 fruits, under certain special conditions, and apart from the 

 action of ferment, are already known to science. They were 

 discovered in 1869 by M. Lechartier, formerly a pupil in the 

 Ecole Nonnale Supirienre, and his coadjutor, M. Bellamy.* 

 In 1821, in a very remarkable work, especially when we 

 consider the period when it appeared, Berard demonstrated 

 several important propositions in connection with the matura- 

 tion of fruits : — 



I. All fruits, even those that are still green, and likewise 

 even those that are exposed to the sun, absorb oxygen and set 

 free an almost equal volume of carbonic acid gas. This is a 

 condition of their proper ripening. 



II. Ripe fruits placed in a limited atmosphere, after having 

 absorbed all the oxygen and set free an almost equal vohxrae of 



result from the use of pits, in -which the beetroots are preserved, when 

 the air is not renewed, and that the original oxygen is expelled by the 

 vital processes of fungi, or other deoxidizing chemical actions. We have 

 directed the attention of the manufacturers of beetroot sugar to this 

 point. 



* Lechartier and Bellamy, Comptes rendus deVAcademie des Sciences, 

 vol. Ixix., pp. 3(36 and 4GG, 1869. 



