The same facts completely upset the hypothesis recently maintained by Messrs. Fremy and Trécul on the subject of the causes of fermentation. “Side by side with the immediate, definite principles which may be formed by synthesis,” says M. Fremy, “such as glucose, oxalic acid, and urea, other substances of greatly inferior stability exist, the constitution of which is considerably more complicated, containing all the elements of living organs, such as carbon, hydrogen, oxygen, nitrogen, and even phosphorus and sulphur; and often salts of lime and of the alkalies besides. These bodies are albumen, fibrin, casein, the congeners of vitellin and others. Chemical synthesis cannot reproduce them. It is impossible, in my opinion, to regard them as immediate, definite principles. I designate them by the general name of _semi-organized_ bodies, because they hold an intermediate place between the immediate principle and the organized tissue. “These semi-organized bodies, which contain all the elements of organs, have the power, like a dry seed-grain, of existing in a state of organic immobility, and of becoming active under circumstances which favour organic development. By reason of the vital energy that they possess they undergo a succession of decompositions, giving origin to new derivatives, and to the advent of ferments, not by any process of _spontaneous generation_, but by a _vital energy_, which pre-exists in the semi-organized bodies, and is simply carried on, when this energy manifests itself, in these most varied organic changes.” After having expressed these hypothetical and confused opinions, M. Fremy continues:—“I do not consider, then, that these semi-organized bodies serve merely as nourishment for certain animal and vegetable organisms, which may be the sole agents of fermentations, but I give them a direct _rôle_ and admit that, under the influences which I have already cited[32] they may assume a real and complete organization, and produce ferments which are not derived, as we have seen, from a germ or an ovum but from a semi-organized body, the vital energy of which has become active.[33] It will be seen that these opinions are quite different from those which M. Pasteur has maintained in his works, since they attribute the origin of alcoholic and lactic ferments to an albuminous substance. Taking the case of alcoholic fermentation alone, I assert that, in the production of wine, it is the juice of the grape itself which, in contact with air, produces grains of yeast, by the transformation of the albuminous substances. M. Pasteur, on the contrary, maintains that the grains of yeast are produced by certain germs.”[34]