Page:Popular Science Monthly Volume 5.djvu/564

546 To conclude, fermentations occasioned in certain media, by the act of development and nutrition of ascertained microscopic animal or vegetable existences, present a group of well-defined characteristics. They follow obediently all the variations that may occur in the physiological activity of the microscopic beings contained in the liquid. This does not go into fermentation all at once; it delays more or less, and molecular movement makes itself perceptible in it by degrees. The phenomenon is one of evolvement. This appears to be the characteristic of alcoholic, lactic, acetic, butyric, glyceric, and putrid fermentations—all of those, in short, which M. Pasteur has studied with so convincing accuracy. Is it the same with the conversion of amylaceous substances into sugar, under the influence of diastase or ptyaline, with the dissolving of proteic substances by pepsin, with the change of amygdaline into the essence of bitter almonds, by contact with synaptase? Evidently not. These phenomena present another aspect; they show no stages of evolvement. Doubtless they require a certain time for their completion; but they take place all at once, and without any relation to the surrounding air.

These differences between the two kinds of fermentation clearly depend on this: that, in the former, the phenomenon is subjected to the conditions and vital progress of those organized corpuscles which elaborate the ferment within the substance of the fermentable liquids, while, in the latter, the phenomenon is brought about by a ferment already formed and prepared. But this latter ferment is no less of organic origin; it, too, arises from living beings, animal or vegetable. Whether it emanates, like diastase, from the young cells of the seed, or results, like pepsin, from work done in the digestive apparatus, it is the labor of life, just as much as if it had been completed by globules of yeast or bundles of bacteria. Thus the efficient sources of all fermentations are the same. All ferments are at bottom alike, whether procured directly for the fermentable liquid by microscopic bodies inhabiting it, or emanating from corpuscles that inhabit elsewhere. The true doctrine of fermentations consists in this point.

Henceforth, then, we may consider ferments as products of a fecundation taking place in cells, as secretions elaborated by those myriads of infinitely little corpuscles, some crowded, squeezed, condensed, into the palpable organs of animals and plants—others free and moving, disseminated, as we shall see, into vast, intangible space. The energy which distinguishes these microscopic animal and vegetable growths also belongs to the microscopic elements making up the living tissues in the higher animals. We must give to this property, hitherto considered as special, the high dignity of a fundamental and universal attribute of organized cells. We must detect, in the most complex conversions and processes of nutrition in superior beings, the same untiring and primitive force that marks the subtile action of invisible and insignificant monads.