Of course, it is sure as the sun following the dawn of to-morrow, that the high deeds of the microbe hunters have not come to an end; there will be others to fashion magic bullets. And they will be waggish men and original, like Paul Ehrlich, for it is not from a mere combination of incessant work and magnificent laboratories that such marvelous cures are to be got.... To-day? Well, to-day there are no microbe hunters who look you solemnly in the eye and tell you that two plus two makes five. Paul Ehrlich was that kind of a man. Born in March of 1854 in Silesia in Germany, he went to the gymnasium at Breslau, and his teacher of literature ordered him to write an essay, subject: “Life is a Dream.” “Life rests on normal oxidations,” wrote that bright young Jew, Paul Ehrlich. “Dreams are an activity of the brain and the activities of the brain are only oxidations ... dreams are a sort of phosphorescence of the brain!” He got a bad mark for such smartness, but then he was always getting bad marks. Out of the gymnasium, he went to a medical school, or rather, to three or four medical schools--Ehrlich was that kind of a medical student. It was the opinion of the distinguished medical faculties of Breslau and Strasbourg and Freiburg and Leipsic that he was no ordinary student. It was also their opinion he was an abominably bad student, which meant that Paul Ehrlich refused to memorize the ten thousand and fifty long words supposed to be needed for the cure of sick patients. He was a revolutionist, he was part of the revolt led by that chemist, Louis Pasteur, and the country doctor, Robert Koch. His professors told Paul Ehrlich to cut up dead bodies and learn the parts of dead bodies; instead he cut up one part of a dead body into very thin slices and set to work to paint these slices with an amazing variety of pretty-colored aniline dyes, bought, borrowed, stolen from under his demonstrator’s nose. He hadn’t a notion of why he liked to do that--though there is no doubt that to the end of his days this man’s chief joy (aside from wild scientific discussions over the beer tables) was in looking at brilliant colors, and making them. “Ho, Paul Ehrlich--what are you doing there?” asked one of his professors, Waldeyer. “Ja, Herr Professor, I am _trying_ with different dyes!” He hated classical training, he called himself a modern, but he had a fine knowledge of Latin, and with this Latin he used to coin his battle cries. For he worked by means of battle cries and slogans rather than logic. “_Corpora non agunt nisi fixata!_” he would shout, pounding the table till the dishes danced--“Bodies do not act unless fixed!” That phrase heartened him through thirty years of failure. “You see! You understand! You know!” he would say, waving his horn-rimmed spectacles in your face, and if you took him seriously you might think that Latin rigmarole (and not his searcher’s brain) carried him to his final triumph. And in a way there is no doubt it did!