from an Agricultural and Veterinanj Point of View. 53 
land, Schwann in Germany, and Cagniard-Latour in France ; 
but its real function was not known, and the chemists proclaimed 
fermentation to be a purely chemical process. The experi- 
ments made by Gay-Lussac at the commencement of this 
century, seemed to them to prove that the oxygen of the air was 
t\ie primum movcns in the process ; and Liebig, in promulgating 
this theory, stated that " the ferments are all nitrogenous sub- 
stances — albumen, fibrine, casein ; or the liquids which contain 
them, as milk, blood, urine — in a state of alteration which they 
undergo in contact with the air." 
The oxygen was the prime agent in breaking up the unstable 
union between the complex molecules of these substances, and 
causing a disturbance and transformation of their ultimate par- 
ticles, resulting in the production of new compounds. Berzelius 
and Mitscherlich, however, explained the phenomena of fer- 
mentation in a different way — the process was one of catalysis — 
the ferment took nothing from, nor did it add anything to, the 
fermentable matter, and was an albuminoid substance pos- 
sessing a catalytic force which enabled it to act by its mere 
presence or contact. Dumas, nevertheless, thought that in the 
budding of the yeast-cells there should be some clue to the 
phenomenon of fermentation, as Cagniard-Latour had already 
surmised in studying the development of the yeast-plant during 
the metamorphosis of sugar in water. But until Pasteur took 
up the subject, it was not in any way or anywhere an accepted 
hypothesis that organisation or life had anv influence on the 
process. 
Pasteur's translation to Lille gave the stimulus to the train 
of thought engendered by the strangeness of the phenomena he 
had witnessed, in regard to the molecular dissymmetry of the two 
tartaric acids, and the effect of a microscopic organism upon 
them, for this had thrown a new light upon the mystery of 
fermentation. The wonderful part played by such a minute 
organism could not be an isolated fact, but beyond it there must 
lie some great general law. It was argued that all that lives 
must die, and all that is dead must be disintegrated, dissolved, 
or gasified ; the elements which are the substratum of life must 
enter into new cycles of life. If things were otherwise, the 
matter of organised beings would encumber the surface of the 
earth, and the law of the perpetuity of life would be com- 
promised by the gradual exhaustion of its materials. One 
grand phenomenon presides over this vast work — the phe- 
nomenon of fermentation. But this is only a word, and it 
suggests to the mind simply the internal movements which all 
organised matter manifests spontaneously after death, without 
the intervention of the hand of man. What is, then, the cause 
of the processes of fermentation, of putrefaction, and of slow 
