8 MODERN VIEWS OF ' CATALYSIS.' [BOOK II. 



in the bodies subjected to its action. According to him, then, the body 

 undergoing fermentation is, in a sense, inductively acted upon by the 

 ferment, but the influence of the latter is a fortuitous one. Liebig believed 

 the ferments to be essentially albuminous bodies, which acquire their fer- 

 ment activities in virtue of their proneness to decomposition, which is 

 so great a characteristic of these bodies in the presence of moisture and 

 a suitable temperature. By this hypothesis, Liebig sought to explain the 

 action of the formed, as well as of the unformed ferments, believing that 

 the processes of life which are characteristic of the former led to the pro- 

 duction of the very unstable substances, whose further putrefactive decom- 

 position he held to constitute the first stage of any process of fermentation. 



There was, it will be remarked, a belief in the accidental, the for- 

 tuitous, nature of ferment actions which inspired this theory of Liebig's. 

 It partook of the spirit which pervaded theories of generation before the 

 days of Redi and Spallanzani. In a sense the view of Liebig appears 

 even more irrational than that of Berzelius, for it assumes a fortuitous 

 behaviour on the part of bodies whose constancy of behaviour under 

 given conditions is a leading characteristic. Though advanced by one 

 whose extraordinary services in the development of modern chemistry 

 cannot be gainsaid, the theory of Liebig was in opposition to a great 

 number of facts already ascertained at the time when it was promulgated, 

 and the erroneous statements upon which it was based tended more to delay 

 than to further the progress of science. 



Whilst the splendid researches of Pasteur 1 at once shewed how far 

 removed are processes of fermentation from the category of fortuitous 

 events, and that every true ferment action which is in any way connected 

 with the changes of a living organism is to be looked upon as the resultant 

 of the chemical activities of that organism, others were proving the 

 groundlessness of other of Liebig's arguments. In a master Jy memoir 2 , 

 Dumas, inter alia, dealt with the physical theory which lay at the very 

 foundation of Liebig's theory, to wit, the possibility of transmitting the 

 state of activity engendered by specific ferments through media which 

 are not pervaded by them. Research soon followed research, which shewed 

 that whilst it is difficult to free the unformed ferments from the proteid 

 bodies which constitute the ground matter of the cell protoplasm in which 

 they are formed, there are but slender grounds for coming to the con- 

 clusion that a ferment is essentially a proteid, much less a proteid in a 

 state of decomposition. 



Have then the more accurate and correct views of catalytic phenomena 

 to which the progress of science has introduced us enabled us to form 

 any conception as to the way in which an unformed ferment may exert 

 its action? To this question we may reply that amongst the phenomena 

 which used formerly to be explained on the mere hypothesis of ' catalysis,' 

 there are some which are suggestive of the kind of interchanges which 

 probably go on between the above ferments and the bodies of which they 

 effect the decomposition. 



1 Pasteur. The student will find it most convenient to read the summary of the 

 very numerous researches in this department of knowledge of this great scientific man 

 in his work entitled 'Etudes sur la Biere.' Paris, Gauthier-Villars, 1876. 



2 Dumas, ' Eecherches sur la fermentation alcoolique.' Comptes Rendus des seances 

 de V Academic des Sciences, T. 75, 1872, p. 276. 



