1 8 THEORIES OF FERMENTATION. 



liquid present. ... In so far as fermentation is synonymous with 

 a reciprocal reaction of organic and inorganic bodies on the con- 

 stituents of a given liquid which may be regarded as forming 

 the nutrient medium of the organic product, so is it necessarily 

 synonymous with every organic vital function : wherefore organic 

 life = fermentation. On the other hand, such processes as lead 

 to the production of vinegar from alcohol by the use of platinum 

 black or other similar methods, cannot be compared with fermen- 

 tation, being purely chemical, whilst fermentation is an organo- 

 chemical process, as is also the life process of any organic body."- 



One of the three members of the committee appointed by the 

 Acade"mie des Sciences of Paris to report on the memoir presented 

 by Cagniard namely, TURPIN (I.) took the opportunity thus 

 afforded of experimentally dilating upon his compatriot's work, 

 and of amalgamating these new "discoveries" with the revelations 

 of Schwann and Kiitzing. In this way a volume, containing more 

 pages than Latour's communication had columns, came into exist- 

 ence, without, however, adding to our knowledge in the slightest 

 degree. Turpin seems, however, to have thoroughly known his 

 public, since he is even now regarded as one of the founders 

 of the vitalistic theory of fermentation, not only by compilers 

 of text-books, but also by actual investigators, from whom one 

 might more reasonably expect a more thorough study of the 

 original works of their predecessors. 



15. Liebig's Decomposition Theory. 



Two years subsequent to the publication of the works of 

 Cagniard, Kiitzing, and Schwann, Liebig placed before his col- 

 leagues a new theory, according to which fermentation was a purely 

 chemical reaction. 



In order to avoid judging this chemist unreasonably, one must 

 bear in mind the age wherein this theory was promulgated. 

 Synthetic organic chemistry had just been founded. Eleven 

 , years previously (1828) Wohler had succeeded in artificially pre- 

 paring urea, to the astonishment of his contemporaries, who had 

 hitherto considered as impossible the artificial production of or- 

 ganic substances outside the animal or vegetable body of whose 

 vital functions they are the outcome. That organic substances 

 could not be produced without the concurrence of vital power 

 was up till that time an established maxim. To overthrow this 

 dogma, and to prove that any desired organic substance can be 

 prepared without the assistance of vital action, was the endeavour 

 of the majority of the chemists of the age, Liebig being one of the 

 foremost, most industrious, and stubbornest workers in the cause. 

 It is, therefore, small matter for astonishment that Cagniard- 

 Latour, Kiitzing, and Schwann to the contrary, notwithstanding 

 he could conceive a theory of fermentation wherein the action 



