Doctor Fehleisen, to take one instance, went out from Koch’s laboratory and found a curious little ball-shaped microbe, hitched to its brothers in chains like the beads of a rosary--he cultivated these bugs from skin gouged out of people sick with erysipelas, that sky-rockety disease that used to be called St. Anthony’s Fire. On the theory that an attack of erysipelas might cure cancer--a mad man’s excuse!--Fehleisen shot billions of these chain microbes, now known as streptococci, into people hopelessly sick with cancer. And in a few days each one of these human experimental animals of his flamed red with St. Anthony’s Fire--some collapsed dangerously and nearly died--and so this desperado proved his case: That streptococcus is the cause of erysipelas. Another pupil of Koch was the now forgotten hero, Doctor Garrè of Basel, who gravely rubbed whole test-tubes full of another kind of microbe--which Pasteur had alleged was the cause of boils--into his own arm. Garrè came down horribly with an enormous carbuncle and twenty boils--the tremendous dose of microbes he shot into himself might easily have finished him--but he dismissed his danger as merely “unpleasant” and shouted triumphantly: “I now know that this microbe, this staphylococcus, is the true cause of boils and carbuncles!” Meanwhile, at the end of 1882, when Koch had finished his virulent and partly comic wrangle with Pasteur, who was just then with prodigious enthusiasm saving the lives of sheep and cattle in France, the discoverer of the tubercle bacillus started sniffing along the trail of one of the most delicate, the most easy to kill, and yet the most terribly savage of all microbes. In 1883 the Asiatic cholera knocked at the door of Europe. This cholera had stolen out of its lurking place in India and slipped mysteriously across the sea and over desert sands to Egypt; suddenly a murderous epidemic of it exploded in Alexandria and Europe across the Mediterranean was frightened. In Alexandria the streets were still with fear; the murderous virus--no one had the slightest notion of what kind of an invisible beast it was--this virus, I say, sneaked into healthy men in the morning, doubled them into knots of spasm-racked agony by afternoon, and put them to rest beyond the reach of all pain by night.