8o6 STUDIES ON FERMENTATION. 



and carbonic acid gas, after the decomposition of this last ; 

 they would be formed where they are found in the cells them- 

 selves, by some process of union between the carbo-hydrates 

 imported by the sap, and the phosphates of potassium and 

 magnesium and salts of ammonia. Lastly, in vegetable growth, 

 bv means of a carbo-hydrate and a mineral medium, since the 

 carbo-hydrate is capable of many variations, and it would be 

 difficult to understand how it could be split up into its elements 

 before serving to constitute the proteic substances, we may hope 

 to obtain as many distinct proteic substances, and even cellulose 

 substances, as there are carbo-hydrates. We have commenced 

 certain studies in this direction. 



If solar radiation is indispensable to the decomposition of 

 carbonic acid and the building up of the primary substances in 

 the case of higher vegetable life, it is still possible that certain 

 inferior organisms may do without it and nevertheless yield 

 the most complex substances, fatty or carbo-hydrate, such as 

 cellulose, various organic acids, and proteic matter ; not, how- 

 ever, by borrowing their carbon from the carbonic acid which 

 is saturated with oxygen, but from other matters still capable 

 of acquiring oxygen, and so of yielding heat in the process, such 

 as alcohol and acetic acid, for example, to cite merely carbon 

 compounds most removed from organization. As these last com- 

 pounds, and a host of others equally adapted to serve as the 

 carbonaceous food of mycodenns and the mucedines, may be 

 produced synthetically by means of carbon and the vapour of 

 water, after the methods that science owes to Berthelot, it 

 follows that, in the case of certain inferior beings, life would 

 be possible even if it should be that the solar light was 

 extinguished.* 



* See on this subject the verbal observations which we addressed to 

 the Academy of Sciences, at its meetings of April lOtb and 24th, 1876. 



