“The virus is dead--or better still very much weakened,” said Pasteur, jumping at the latter conclusion with no sense or reason. “Now we’ll try drying other pieces of virulent stuff for twelve days--ten days--eight days--six days, and see if we can’t just give our dogs a _little_ rabies ... then they ought to be immune....” Savagely they fell to this long will o’ the wisp of an experiment. For fourteen days Pasteur walked up and down the bottle and microscope and cage-strewn unearthly workshop and grumbled and fretted and made scrawls in that everlasting notebook of his. The first day the dogs were dosed with the weakened--the almost extinct virus that had been dried for fourteen days; the second day they received a shot of the slightly stronger nerve stuff that had been thirteen days in its bottle; and so on until the fourteenth day--when each beast was injected with one-day-dried virus that would have surely killed a not-inoculated animal. For weeks they waited--hair graying again--for signs of rabies in these animals, but none ever came. They were happy, these ghoulish fighters of death! Their clumsy terrible fourteen vaccinations had not hurt the dogs--but were they immune? Pasteur dreaded it--if this failed all of these years of work had gone for nothing, and “I am getting old, old ...” you can hear him whispering to himself. But the test had to be made. Would the dogs stand an injection of the most deadly rabid virus--right into their brains--a business that killed an ordinary dog one hundred times out of one hundred? Then one day Roux bored little holes through the skulls of two vaccinated dogs--and two not vaccinated ones: and into all four went a heavy dose of the most virulent virus.... One month later, Pasteur and his men, at the end of three years of work, knew that victory over hydrophobia was in their hands. For, while the two vaccinated dogs romped and sniffed about their cages with never a sign of anything ailing them--the two that had not received the fourteen protective doses of dried rabbit’s brain--these two had howled their last howls and died of rabies. Now immediately--the life-saver in this man was always downing the mere searcher--Pasteur’s head buzzed with plans to wipe hydrophobia from the earth, he had a hundred foolish projects, and he walked in a brown world of thought, in a mist of plans that Roux and Chamberland, and not even Madame Pasteur could penetrate. It was 1884, and when Pasteur forgot their wedding anniversary, the long-suffering lady wrote to her daughter: “Your father is absorbed in his thoughts, talks little, sleeps little, rises at dawn, and, in one word, continues the life I began with him this day thirty-five years ago.”