Indeed, why wasn’t this setting out to tame the hydrophobia virus--why wasn’t it a nonsensical wild-goose chase? There was in all human history no single record of any man or beast getting better from this horrible malady, once the symptoms had declared themselves, once the mysterious messengers of evil had wormed their unseen way into the spinal cord and brain. It was this kind of murderous stuff that Pasteur and his men balanced on the tips of their knives, sucked up into their glass pipettes within an inch from the lips--stuff that was separated from their mouths by a thin little wisp of cotton.... Then, one exciting day, the first sweet music of encouragement came to these gropers in the dark--one of their dogs inoculated with the surely fatal stuff from a rabid rabbit’s brain--this dog came down with his weird barkings and portentous shiverings and slatherings--and then miraculously got completely better! Excitedly, a few weeks later, they shot this first of all recovered beasts with a deadly virus, directly into his brain they injected the wee murderers. The little wound on his head healed quickly--anxiously Pasteur waited for his doomful symptoms to come on him, but these signs never came. For months the dog romped about his cage. He was absolutely immune! “Now we know it--we know we have a chance.... When a beast once has rabies and gets better from it, there will be no recurrence.... We must find a way to _tame_ the virus now,” said Pasteur to his men, who agreed, but were perfectly certain that there was no way to tame that virus. But Pasteur began inventing experiments that no god would have attempted; his desk was strewn with hieroglyphic scrawls of them. And at eleven in the morning, when the records of the results of the day before had been carefully put down, he would call Roux and Chamberland, and to them he would read off some wild plan for groping after this unseen unreachable virus--some fantastic plan for getting his fingers on it _inside_ the body of a rabbit--to weaken it. “Try this experiment to-day!” Pasteur would tell them. “But that is technically impossible!” they protested. “No matter--plan it any way you wish, provided you do it well,” Pasteur replied. (He was, those days, like old Ludwig van Beethoven writing unplayable horn parts for his symphonies--and then miraculously discovering hornblowers to play those parts.) For, one way or another, the ingenious Roux and Chamberland devised tricks to do those crazy experiments.... And at last they found a way of weakening the savage hydrophobia virus--by taking out a little section of the spinal cord of a rabbit dead of rabies, and hanging this bit of deadly stuff up to dry in a germ-proof bottle for fourteen days. This shriveled bit of nervous tissue that had once been so deadly they shot into the brains of healthy dogs--and those dogs did not die....