tion, to which the researches of Pouchet had just given fresh interest. Trained as Pasteur was in the experimental sciences, he had an immense advantage over Pouchet, whose culture was derived from the sciences of observation. One by one the statements and experiments of Pouchet were explained or overthrown, and the doctrine of spontaneous generation remained discredited until it was revived with ardor, ability, and, for a time, with success, by Dr. Bastian.
A remark of M. Radot's on page 103 needs some qualification. "The great interest of Pasteur's method consists," he says, "in its proving unanswerably that the origin of life in infusions which have been heated to the boiling-point is solely due to the solid particles suspended in the air." This means that living germs can not exist in the liquid when once raised to a temperature of 212° Fahr. No doubt a great number of organisms collapse at this temperature; some, indeed, as M. Pasteur has shown, are destroyed at a temperature 90° below the boiling-point. But this is by no means universally the case. The spores of the hay-bacillus, for example, have in numerous instances successfully resisted the boiling temperature for one, two, three, four hours; while in one instance eight hours' continuous boiling failed to sterilize an infusion of desiccated hay. The knowledge of this fact caused me a little anxiety some years ago when a meeting was projected between M. Pasteur and Dr. Bastian. For though, in regard to the main question, I knew that the upholder of spontaneous generation could not win, on the particular issue touching the death temperature he might have come off victor.
The manufacture and maladies of wine next occupied Pasteur's attention. He had, in fact, got the key to this whole series of problems, and he knew how to use it. Each of the disorders of wine was traced to its specific organism, which, acting as a ferment, produced substances the reverse of agreeable to the palate. By the simplest of devices, Pasteur, at a stroke, abolished the causes of wine-disease. Fortunately the foreign organisms which, if unchecked, destroy the best red wines, are extremely sensitive to heat. A temperature of 50° C. (122° Fahr.) suffices to kill them. Bottled wines once raised to this temperature, for a single minute, are secured from subsequent deterioration. The wines suffer in no degree from exposure to this temperature. The manner in which Pasteur proved this, by invoking the judgment of the wine-tasters of Paris, is as amusing as it is interesting.
Moved by the entreaty of his master, the illustrious Dumas, Pasteur took up the investigation of the diseases of silk-worms at a time when the silk-husbandry of France was in a state of ruin. In doing so he did not, as might appear, entirely forsake his former line of research. Previous investigators had got so far as to discover vibratory corpuscles in the blood of the diseased worms, and with such corpuscles Pasteur had already made himself intimately acquainted. He was,
