Footnote 76: We found, after the lapse of another year, in December, 1873, that the ferment of the _mucor_ in the test glass might still be easily revived; that it was able to propagate, both in the mycelium and in the cellular form, in wort, and that it might produce a fermentation, more or less active, according to the condition of aeration; in short, that it was capable of producing all the characteristic phenomena described. By means of the method of cultivation that we employ, our study, which was continued for years, was pursued without the least fear of any foreign fungoid growths being introduced into the vessels, although they remained constantly open, and the air in them was being perpetually renewed by the action of diffusion and variations of temperature. In 1875 nothing remained alive in our flask, and further revival became impossible. Footnote 77: We do not here take into account certain phenomena of oxidation of which the fungoid growths are the seat, and which remind us of those that are presented in so remarkable a degree by _mycoderma vini_ and _mycoderma aceti_. Footnote 78: [There are 15·43 grains in the gramme.] Footnote 79: [For English equivalent see Experiment 1, p. 135.] Footnote 80: The figure given below supplies this omission. The cells that are isolated or are in chains, _b.b.b._, show this state of the old cells. The cells _a.a.a._ are younger, and may be more easily revived. We may see by the dimensions of some of these how greatly, in certain cases, the cells of _mucor_ resemble cells of yeast; nevertheless, in the state of the contents and the aspect of the outlines, there are always some differences sufficiently appreciable to strike the practised observer. [Illustration: Fig. 23.] The figures adjoining the cells indicate fractions of a millimetre. (A millimetre may be taken as ½5-in.) Footnote 81: [0·000089 in., 0·00026 in. and O·00089 in. respectively.] CHAPTER V. The Alcoholic Ferments. § I.—On the Origin of Ferment. Amongst the productions that appear spontaneously, or, we should rather say, without direct impregnation, in organic liquids exposed to contact with the air, there is one that more particularly claims our study. It is that one which, by reason of its active energy as an agent of decomposition, has been distinguished and utilized from the earliest times, and is considered as the type of ferments in general; we mean the ferment of wine, beer, and more generally, of all fermented beverages.