Finally, if pure alcoholized water does not become acetified, though germs can drop into it from the air, it is because it does not offer to those germs the food necessary to the plant--food which is present in wine but not in alcoholized water. But if a suitable aliment for the little plant is added to the water, acetification takes place. When the acetification is complete, the mycoderma, if not submerged, continues to act, and, when not arrested in time, its oxidating power becomes dangerous; having no more alcohol to act upon, it ends by transforming acetic acid itself into water and carbonic acid gas, and the work of death and destruction is thus achieved. Speaking of that last phase of the mycoderma aceti, he went on to general laws--laws of the universe by which all that has lived must disappear. “It is an absolute necessity that the matter of which living beings are formed should return after their death to the ground and to the atmosphere in the shape of mineral or gaseous substances, such as steam, carbonic acid gas, ammoniac gas or nitrogen--simple principles easily displaced by movements of the atmosphere and in which life is again enabled to seek the elements of its indefinite perpetuity. It is chiefly through acts of fermentation and slow combustion that this law of dissolution and return to a gaseous state is accomplished.” Coming back to his special subject, he pointed out to vinegar manufacturers the cause of certain failures and the danger of certain errors. It was imagined for instance that some microscopic beings, anguillulæ, of which Pasteur projected an enlarged wriggling image on the screen, and which were to be found in the tubs of some Orleans vinegar works, were of some practical utility. Pasteur explained their injurious character: as they require air to live, and as the mycoderma, in order to accomplish its work, is equally dependent on oxygen, a struggle takes place between the anguillulæ and the mycoderma. If acetification is successful, if the mycoderma spreads and invades everything, the vanquished anguillulæ are obliged to take refuge against the sides of the barrel, from which their little living army watches the least accidental break of the veil. Pasteur, armed with a magnifying glass, had many times witnessed the struggle for life which takes place between the little fungi and the tiny animals, each fighting for the surface of the liquid. Sometimes, gathering themselves into masses, the anguillulæ succeed in sinking a fragment of the mycodermic veil and victoriously destroying the action of the drowned plants.