226 M. Berzelius on a New Power which acts in 



dies ; and it became possible to deduce from it certain applica- 

 tions. We now know, for example, that, in the act of fermen- 

 tation, in the transformation of sugar into alcohol and carbonic 

 acid, the change which is eflPected by the insoluble substance which 

 is calhdyi'rment or yeast, and which may be replaced, though 

 with less certainty, by animal fibrine, by albumen, by cheesy 

 matters, &c. &c. cannot be explained by any chemical action be- 

 tween sugar and yeast, and that no phenomenon in unorganis- 

 ed bodies approaches it so nearly as the action of platinum, of 

 silver, and of fibrine, in the decomposition of the peroxide of 

 hydrogen into oxygen and water. It was, therefore, only na- 

 tural to suppose that the mode of acting of yeast was analo- 

 gous. 



The transformation- of starch into sugar, by means of sul- 

 phuric acid, had not hitherto been arranged and connected with 

 the preceding facts ; nevertheless, the discovery of diastase, a 

 substance which acts upon starch in a similar manner, but with 

 much greater energy, directed attention to this analogy ; and the 

 parallel was completely demonstrated to our satisfaction by the 

 ingenious researches of M. Mitscherlich regarding the formation 

 of ether. Among the many theories respecting the formation 

 of ether, one, as is well known, made the power of the sulphuric 

 acid to transform the alcohol into ether to depend upon its power 

 of combining with water, admitting that the alcohol, considered as 

 a compound of one atom of etherine (C^ff) and two atoms of wa- 

 ter, was converted into ether, by yielding the half of its water to 

 the acid. This theory, as simple as it was ingenious, was in 

 perfect harmony with our knowledge of the actions of the affini- 

 ties of bodies ; but, notwithstanding, it did not explain why 

 other non-acidulous bodies, as strongly disposed for water, did 

 not also produce ether. The researches of M. Mitscherlich 

 now prove that sulphuric acid, properly diluted, and taken at 

 such a temperature that the refrigeration produced by the ad- 

 dition of the alcohol may compensate for the heat which is pro- 

 duced by the mixture, decomposed the former into ether and 

 water, both of which, owing to the temperature surpassing the 

 boiling point of water, separated themselves by distillation from 

 the mass, and presented, when completely condensed, a mixture 

 of the same weight with that of the alcohol employed. The 



