Ferments and their actions / by Carl Oppenheimer ; Translated from the German by C. Ainsworth Mitchell.

Date:
1901
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Licence: In copyright

Credit: Ferments and their actions / by Carl Oppenheimer ; Translated from the German by C. Ainsworth Mitchell. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    fermentative process is. On the other hand, the purely biological conception renounces all dynamic investigation of the fermenta- tive process; it reduces the problem to one of the phenomena of the vital process which offers to us so many enigmas, and claims to have given an “ explanation” of a new problem, by grouping it with an old equally unsolved problem. Thus, in reality, the fight was not for the same object. Liebig contended for a theoretical conception ; Pasteur, primarily, for a biological connec- tion. It is true that Pasteur also formed a theory of the action of yeast, based upon his biological discoveries; but, on the one hand, this was also purely biological, completely separating the process of alcoholic fermentation, even in theory, from other fermentative processes; whilst, on the other hand, it could be shown to be false in its special assumptions. But since Liebig also opposed the facts on which this biological conception was based, as well as all intimate connection between vital activity and fermentation, it followed that with the refutation of his objections his whole point of view had also to give way in favour of Pasteur’s conception based upon victorious facts. And it soon became perfectly clear that in the process of alco- holic fermentation, living cells actually did play the important part which Cagniard - Latour and Schwann had ascribed to them. Proofs which confirmed and extended Schwann’s results in- creased. Helmholtz 1 found that alcoholic fermentation did not pass through membranes—a fact which supported the conclusion of living non-diffusible cells being the cause; Schroder and v„. Dusch 2 showed that mere filtration of the air through thick cotton-wool filters was sufficient to prevent fermentation in liquids. All these experiments, however, were incapable of breaking down the resistance of the opponents of this view. Then Pasteur3 entered the lists, and his experiments proved,, with absolute certainty, that living germs were really necessary for the production of fermentation, and that these living germs very rapidly gained admission to liquids as soon as they were Helmholtz, J. pr. Ch., xxxi., 429, 1884; c/., on the other hand, Popping and Struve, J. pr. Ch., xli., 41, 255, 1847. 2 Schroder and v. Dusch, quoted by Mayer, loc. cit., 55. 3 Pasteur made known the results of his researches in numerous publica- tions. See, inter alia, Comptes Pendus, h, 304, 849, 1083; li., 348, 675 lid., 1260; Ann. d. Chim. et. Phys. [3], lviii., 323; [4], xxv., 145 (against Liebig) ; also his general survey in Etudes sur la bidre; Etudes silv le vin; and Die Atkoholgdhrung, German translation by Griessmayer, Stuttgart, 1871, 2nd Ed., 1878. See also the brilliant critical survey by Dumas, Ann. de Chim. et Phys, [5], iii., 57.