The initiation of the fermentation process does not require so complicated an apparatus as is represented by the living cell. The agent responsible for the fermenting action of the press juice is rather to be regarded as a dissolved substance, doubtless a protein; this will be denoted zymase.

This [discovery of a cell-free yeast extract] will make him famous, even though he has no talent for chemistry.

Through the discovery of Buchner, Biology was relieved of another fragment of mysticism. The splitting up of sugar into CO₂ and alcohol is no more the effect of a 'vital principle' than the splitting up of cane sugar by invertase. The history of this problem is instructive, as it warns us against considering problems as beyond our reach because they have not yet found their solution.