FERMENTATION. 77 



and maintains that he has observed that fermentation 

 and the formation of ferment cells begin simulta- 

 neously. He observed that acetic, lactic, phosphoric, 

 and tarfcaric acid materially assist the formation of 

 ferment, whilst the presence of sulphuric, muriatic, 

 and nitric acid retards this process.* 



No more details are necessary concerning this mat- 

 ter, as these appear to me conclusive. 



It cannot, indeed, be affirmed that this opinion 

 respecting the action of ferment has always been ad- 

 mitted. Perhaps nothing in science has been so 

 variously represented as the theory of fermentation ; 

 the most extravagant ideas have been repeatedly 

 formed concerning it, and each was grounded upon 

 observation and experiment. We will notice the 

 following as shortly as possible. We may dismiss 

 with one word the promulgators of the opinion that 

 fermentation is an operation caused by a plant in 

 process of formation (even supposing that plant to 

 consist of a single cell, to which other cells may, at a 

 later period, affix themselves independently), such as 

 Schwann,t Quevenne,J Kiitzing, Turpin,|| Cagniard 

 la Tour.^[ They have the merit of having describe^! 

 and drawn attention to the cellular nature of well- 



* See also Helmholz. Journ. f. Prakt. Chemie, Bd. 31. s. 429. 

 Brendecke (Archiv. der Pharm. Bd. 90, s. 10, and Bd. 93, s. 133.) 

 Dubrunfaut, Ann. de Ch. et de Phys. t. xxi. p. 169. 



t Pogg, Ann. Bd. 41, s. 284. J Journ. de Pharm. An. 1841. 



Erdraann's Journ. 1838. || L'Institut. 1835, 1836, 1841. 



; Journ. de Pharm. t. xLi. p. 244. 



