Pasteur was in his late fifties now, but he was still as impetuous and enthusiastic as he had been at twenty-five. He had been a chemist and an expert on beet-sugar fermentations, he had shown the vintners how to keep their wines from spoiling, he had rushed from this job into the saving of sick silkworms, he had preached the slogan of Better Beer for France and had really made the French beer better; but during all these hectic years while he was doing the life work of a dozen men Pasteur dreamed about the tracking down of microbes that he knew must be the scourges of the human race, the authors of disease. Then suddenly he found Koch had done the trick ahead of him. He must catch up with this Koch. “Microbes are in a way mine--I was the first to show how important they were, twenty years ago, when Koch was a child....” you can imagine Pasteur muttering. But there were difficulties in the way of his catching up. In the first place, Pasteur had never felt a pulse or told a bilious man to stick out his tongue, it is doubtful if he could have told a lung from a liver, and it is certain that he did not know the first thing about how to hold a scalpel. As for those cursed hospitals--phew! The smell of them gave him nasty feelings at the pit of his stomach, and he wanted to stop his ears and run away from the moans that floated down their dingy corridors. But presently--it was ever the way with this unconquerable man--he got around his medical ignorance. Three physicians, Joubert at first, and then Roux and Chamberland became his assistants; youngsters they were, these three, radicals who were Bolshevik against ancient idiotic medical doctrines. They sat worshiping Pasteur at his unpopular lectures in the Academy of Medicine, believing every one of his laughed-at prophecies of dreadful scourges caused by sub-visible bugs. He took these boys into his laboratory and in return they explained the machinery of animals’ insides to Pasteur, they taught him the difference between the needle and the plunger of a hypodermic syringe and convinced him--he was very squeamish about such things--that animals like guinea-pigs and rabbits hardly felt the prick of the syringe needle when he injected them. Privately these three men swore to be his slaves--and the priests of this new science....