So, in 1899, when he was forty-five, if he had died then, Ehrlich would certainly still have been called a failure. His efforts to find laws for serums had resulted in a collection of fantastic pictures that nobody took very seriously, they certainly had done nothing to turn feebly curative serums into powerful ones--what to do? First, this to do, thought Ehrlich, and he pulled his wires and cajoled his influential friends, and presently the indispensable and estimable Mr. Kadereit, his chief cook and bottle-washer, was dismounting that laboratory at Steglitz--they were moving to Frankfort-on-the-Main, away from the vast medical schools and scientific buzzings of Berlin. What to do? Well, Frankfort was near those factories where the master-chemists turned out their endless bouquets of pretty colors--what could be more important for Paul Ehrlich? Then there were rich Jews in Frankfort, and these rich Jews were famous for their public spirit, and money--_Geld_, that was one of his four big “G’s,” along with _Geduld_--patience, _Geshick_--cleverness and _Glück_--luck, which Ehrlich always said were needed to find the magic bullet. So Paul Ehrlich came to Frankfort-on-the-Main, or rather, “WE came to Frankfort-on-the-Main,” said the valuable Mr. Kadereit, who had the very devil of a time moving all of those dyes and that litter of be-penciled and dog-eared chemical journals. Reading this history, you might think there was only one good kind of microbe hunter: the kind of searcher who stood on his own absolutely, who paid little attention to the work of other microbe hunters, who read nature and not books. But Paul Ehrlich was not that kind of man! He rarely observed nature, unless it was the pet toad in his garden, whose activities helped Ehrlich to prophesy the weather--it was Mr. Kadereit’s first duty to bring plenty of flies to that toad.... No, Paul Ehrlich got his ideas out of books.