remain absent forever, because that which constitutes essentially the life of those beings, for the nourishment of which this liquid is appropriate, has not been added. Let us then introduce life there, let us sow vibrios in it. We place in the little funnel which surmounts the straight tube of our flask, the one closed by a glass faucet, a small quantity of one of those organic liquids in which vibrios are found after exposure to the air; or, better yet, and that is what has been done here, let us place in the funnel some liquid, the same exactly as that contained in the flask, but which has been exposed to the air and in which vibrios have appeared. Let us now turn the faucet and introduce a few drops with their vibrios into the flask.
Singular phenomena appear soon after this sowing of life in our mineral solution. The liquid, which was as limpid as distilled water, becomes little by little opalescent during the following days, and at the same time gases are set free and rise in the form of small bubbles to the top of the flask. This gas is a mixture of hydrogen and carbonic acid, and at the same time the lactic acid is transformed into butyric acid, which unites with a part of the lime of the lactate, the rest of which combines with the carbonic acid. It is a real putrefaction of the lactic acid which has taken place, but a putrefaction without putridity, for the lactic acid contains neither sulphur nor phosphorus, those elements of offensive gaseous combinations which are deleterious for man but inoffensive for vibrios. No, I am wrong: putridity shows itself, but in so slight a degree that it is almost inappreciable. Phosphorus and sulphur are present in the phosphates and sulphates; these are decomposed, hence a slight odor and even quite frequently a gray color given to the precipitate, probably by a little sulphuret of iron, for iron is almost always present, even in the purest materials.
Whence come all these mysterious transformations? Microscopical examination of a drop of this liquid which has lost its primitive limpidity will tell us. Wonderful spectacle! Beings in the form of small rods go and come, stop and recommence their movements. They are single or united in pairs, twos, threes, and even more. Here are a pair which separate from one another by a sort of effort, more or less prolonged on the part of the two individuals composing it. And now each half has its own movements; this is generation by scission. Now I know why the liquid is milky. What our eyes in their weakness call milkiness the microscope shows us is a consequence of the life of these little beings and of their incessant movements. And the experiment, patiently followed out, will tell us that the life lasts as long as does the principal food of our little beings, that is, the lactic acid of the lactate of lime, provided always that all the other general conditions of existence be satisfied; for it is not enough to have food at our disposal, we must be able to assimilate it, and it is necessary that the functional trouble which you call pathology should
