M. Fremy maintains that certain experiments which he has made controvert the position of the upholders of the physiological theory. At a session of the French academy of sciences held in October, 1872, a discussion of the subject took place between M. Pasteur and M. Fremy, in which the latter contended that the influence of atmospheric dust in the phenomena of fermentation is only secondary and accidental, and that the true origin of ferments is in the mass of the fermentable substance. Fremy is disposed to believe that Pasteur did not establish fermentation in the boiled must in which he had placed grape juice, because he placed it in other conditions, besides those of exclusion of air, in which alcoholic fermentation could not take place. He recounted some experiments which he had made, among which was the following: He squeezed the pulp of some pears and other fruits, but without breaking the skins, and placing them in favorable situations, found at the end of several days that they contained notable quantities of alcohol; fermentation having been produced in the interior of the fruit where, in his opinion, the dust of the air could not exert any influence.

Fremy therefore believes that the parenchyma of fruits contains the material which is capable of taking on conditions by which it may form ferments. He contends that there is a great number of ferments that are neither organized nor living, which are capable of producing various kinds of fermentation, depending upon the conditions in which the fermentable matter is placed. Liebig compares the action of a ferment to that of heat, by which the atomic constituents of organic molecules are shaken asunder and left to recombine under the influence of forces that may be present. Acetic acid is separated by heat into carbonic acid and acetone; just as sugar is separated by yeast into carbonic acid and alcohol. He regards vital action and chemical action as phenomena which must be considered separately in seeking an explana-' tion of fermentation, and holds that the fact that yeast causes fermentation in a pure solution of sugar is opposed to the idea that the decomposition of sugar is caused by the development and increase of yeast cells; for yeast consists chiefly of a substance containing nitrogen and sulphur, besides phosphates, and these cannot be furnished by the sugar; and more-over, beer yeast causes a similar decomposition of other substances, malate of lime being converted into carbonic acid, acetate, carbonate, and succinate of lime.

Salicine is also decomposed by yeast into saligenine and salicylic acid; and a similar decomposition of salicine is produced by emulsine without any recognizable physiological process being concerned in the change. Emulsine acts upon amygdaline in like manner, its effects being recognizable in a few minutes by the new products. Emulsion of sweet almonds also undergoes active vinous fermentation when mixed with grape sugar. But if substances containing sulphur and nitrogen, like emulsine, are, by reason of alteration in the arrangement of their atoms, capable of inducing change in other organic molecules, so that they separate into new products, there is reason for suspecting that in the action which yeast exerts upon sugar its sulphuretted and nitrogenous constituent plays a similar part." On the other hand, the experiments of Hallier are more in support of the views of Pasteur. According to this observer, the same germinal molecules develop, according to the nature of the fermentable substances in which they are deposited, into the fungoid forms peculiar to each fermentation. The forms which induce putrefaction, fermentation, and mildew are all varieties of one another.

When they are de-veloped within the fluids they are cellular formations, but when they grow upon the surface they produce fructification. Hallier agrees with Pasteur's view that the germs are all carried. by the air. The following, condensed from the Quarterly Journal of Science," is a brief summary of Hallier's views. The most abundant source of germs appears to be the penieillium crustaceum (fig. 4), whose spores are universally spread because it is more hardy, more fertile, and develops at lower temperatures than others of its kind. A spore of penicillium falling into a watery fluid bursts into a multitude of particles, each of which may be the radicle of a living fungus. The minute particles unite in twos, forming a double cell, and divide with great rapidity. (See fig. 5.) The minute particles then unite in chains, constituting lepto-thrix, which is not a species, but a form of vegetation common to many species. In pure water development can go no further, and after a few hours the organisms cease to be formed, the presence of a nitrogenous substance being necessary for further development. The minute spherules, micrococci, are the special ferment of putrefaction.

In the presence of sugar the spherule enlarges and becomes a nucleated cell, cryptococcus, which is identical with the yeast cell. (See tig. 6.) In milk, during lacteous fermentation, the micrococcus elongates and forms jointed staff-like cells, as in tig. 7, arthrococcus; and in acetic fermentation the cells become lancet-shaped. According to these views, alcoholic and putrefactive fermentations are both due to the influence of a single agent, transported from place to place in the air, which everywhere contains germinal matter, protoplasm, bioplasm, or whatever it may be called; the living molecules growing wherever they find a suitable soil, and in different soils developing into different forms, producing by their vital acts different effects. The microscopic investigations of Dr. Beale upon the development of the yeast plant show that the cells vary in size more than is usually represented, and that the development of buds is greater, the layer cells having as many as ten or more buds. (See figs. 1 and 3.) He says: The different germinal matter within the yeast cell is the material upon which alone all growth and action depends.