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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 dies. . . .

"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