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Pasteur's life was becoming more and more unlike the austere cloistered existence that most men of science lead. His experiments became powerful answers to the objections that swarmed on every side against his theory of germs, they became loud public answers to such objections—rather than calm quests after facts; but in spite of his dragging science into the market place, there is no doubt that his experiments were marvelously made, that they fired the hopes and the imagination of the world. He got himself into a noisy argument on the way yeasts turn grape juice into wine, with two French naturalists, Frémy and Trécul. Frémy admitted that yeasts were needed to make alcohol from grape juice, but he argued ignorantly before the amused Academy that yeasts were spontaneously generated inside of grapes. The wise men of the Academy pooh-poohed; they were amused, all except Pasteur.

"So Frémy says that yeasts rise by themselves inside the grape!" cried Pasteur. "Well, let him answer this experiment then!" He took a great number of round-bellied flasks and filled them part full of grape juice. He drew each one out into a swan's neck; then he boiled the grape juice in all of them for a few minutes and for days and weeks this grape juice, in every one of all these flasks, showed no bubbles, no yeasts, there was no fermentation in them. Then Pasteur went to a vineyard and gathered a few grapes—they were just ripe—and with a pure water he washed the outsides of them with a clean, heated, badger hairbrush. He put a drop of the wash water under his lens—sure enough!—there were globules, a few wee globes, of yeasts. Then he took ten of his swan neck flasks and ingeniously sealed straight tubes of glass into their sides, and through these straight tubes in each one he put a drop of this wash water from the ripe grapes. Presto! Every one of