Microbe Hunters

by Paul De Kruif

  In that spit-gland, feebly, lazily moving in it, but swarming in such myriads that they made it quiver, almost, under his lens, were those regiments and armies of spindle-shaped threads, hopeful valiant young microbes of malaria, ready to march up the tube to the mosquito's stinger. . .

  “It's by the bite mosquitoes carry malaria then,” Ross whispered—he whispered it because that was contrary to the theory of his scientific father, Patrick Manson. “It is all nonsense that birds—or people either—get malaria by drinking dead mosquitoes, or by inhaling the dust of mosquitoes. . . ” Ronald Ross had always been loyal to Patrick Manson. But now! Never has there been a finer instance of wrong theories leading a microbe hunter to unsuspected facts. But now! Ronald Ross needed no help. He was a searcher.

  “It's by the bite!” shouted Ronald Ross, so, on the twenty-fifth day of June in 1898, Mr. Mahomed Bux brought in three perfectly healthy sparrows—fine sparrows with not a single microbe of malaria in their blood. That night, and night after night after that night, with Ronald Ross watching, Mr. Mahomed Bux let into the cage with those healthy sparrows a flock of poisonous she-mosquitoes who had fed on sick birds. . . And Ronald Ross, fidgety as a father waiting news of his first-born child, biting his mustache, sweating, and sweating more yet because he used up so much of himself cursing at his sweat—Ross watched those messengers of death bite the healthy sparrows. . .

  On the ninth of July Ross wrote to Patrick Manson: “All three birds, perfectly healthy before, are now simply swarming with proteosoma.” (Proteosoma are the malarial parasites of birds.)

  Now Ronald Ross did anything but live remotely on his mountain top. He wrote this to Manson, he wired it to Manson, he wrote it to Paris to old Alphonse Laveran, the discoverer of the malaria microbe; he sent papers to one scientific journal and two medical journals about it; he told everybody in Calcutta about it; he bragged about it—in short, this Ronald Ross was like a boy who had just made his first kite finding that the kite could really fly. He went wild—and then (it is too bad!) he collapsed. Patrick Manson went to Edinburgh and told the doctors of the great medical congress about the miracle of the sojourn and the growing and the meanderings of the malaria microbes in the bodies of gray she-mosquitoes: he described how his protegé Ronald Ross, alone, obscure, laughed at, but tenacious, had tracked the germ of malaria from the blood of a bird through the belly and body of she-mosquitoes to their dangerous position in her stinger, ready to be shot into the next bird she bit.

  The learned doctors gaped. Then Patrick Manson read out a telegram from Ronald Ross. It was the final proof: the bite of a malarial mosquito had given a healthy bird malaria! The congress—this is the custom of congresses—permitted itself a dignified furore, and passed a resolution congratulating this unknown Major Ronald Ross on his “Great and Epoch-Making Discovery.” The congress—it is the habit of congresses—believed that what is true for birds goes for men too. The congress—men in the mass are ever uncritical—thought that this meant malaria would be wiped out from to-morrow on and forever—for what is simpler than to kill mosquitoes? So that congress permitted itself a furore.

  But Patrick Manson was not so sure: “One can object that the fact determined for birds do not hold, necessarily, for men.” He was right. There was the rub. This was what Ronald Ross seemed to forget: that nature is everlastingly full of surprises and annoying exceptions, and if there are laws and rules for the movements of the planets, there may be absolutely no apparent rime and less reason for the meanderings of the microbes of malaria. . . Searchers, the best of them, still do no more than scratch the surface of the most amazing mysteries, all they can do (yet!) to find truth about microbes is to hunt, hunt endlessly. . . There are no laws!

  So Patrick Manson was stern with Ronald Ross. This nervous man, feeling he could stand this cursed India not one moment longer, must stand it months longer, years longer! He had made a brilliant beginning, but only a beginning. He must keep on, if not for science, or for himself, then for England! For England! And in October Manson wrote him: “I hear Koch has failed with the mosquito in Italy, so you have time to grab the discovery for England.”

  But Ronald Ross—alas—could not grab that discovery of human malaria, not for science, nor humanity, nor for England—nor (what was worst) for himself. He had come to the end of his rope. And among all microbe hunters, there is for me no more tortured man than this same Ronald Ross. There have been searchers who have failed—they have kept on hunting with the naturalness of ducks swimming; there have been searchers who have succeeded gloriously—but they were hunters born, and they kept on hunting in spite of the seductions of glory. But Ross! Here was a man who could only do patient experiments—with a tragic impatience, in agony, against the clamoring of his instincts that yelled against the priceless loneliness that is the one condition for all true searching. He had visions of himself at the head of important committees, and you can feel his dreams of medals and banquets and the hosannahs of multitudes. . .

  He must grab the discovery for England. He tried gray mosquitoes and green and brown and dappled-winged mosquitoes on Hindus rotten with malaria—but it was no go! He became sleepless and lost eleven pounds. He forgot things. He could not repeat even those first crude experiments at Secunderabad.

  And yet—all honor to Ronald Ross. He did marvelous things in spite of himself. It was his travail that helped the learned, the expert, the indignant Battista Grassi to do those clean superb experiments that must end in wiping malaria from the earth.

  6

  You might know Giovanni Battista Grassi would be the man to do what Ronald Ross had not quite succeeded in bringing off. He had been educated for a doctor, at Pavia where that glittering Spallanzani had held forth amid applause a hundred years before. Grassi had been educated for a doctor (Heaven knows why) because he had no sooner got his license than he set himself up in business as a searcher in zoology. With a certain amount of sunfishes he always insisted: “I am a zoologo—not a medico!” Deliberate as a glacier, precise as a ship's chronometer, he started finding answers to the puzzles of nature. Correct answers! His works were pronounced classics right after he published them—but it was his habit not to publish them for years after he started to do them. He made known the secret comings and goings of the Society of the White Ants—not only this, but he discovered microbes that plagued and preyed upon these white ants. He knew more than any man in the world about eels—and you may believe it took a searcher with the insight of a Spallanzani to trace out the weird and romantic changes that eels undergo to fulfill their destiny as eels. Grassi was not strong. He had abominable eyesight. He was full of an argumentative petulance. He was a contradictory combination of a man too modest to want his picture in the papers but bawling at the same time for the last jot and tittle of credit for everything that he did. And he did everything. Already, when he was only twenty-nine, before Ross had dreamt of becoming a searcher, Battista Grassi was a professor, and had published his famous monograph upon the Chaetognatha (I do not know what they are!).

  Before Ronald Ross knew that anybody had ever thought of mosquitoes carrying malaria, Grassi had had the idea, had taken a whirl at experiments on it, but had used the wrong mosquito, and failed. But that failure started ideas stewing in his head while he worked at other things—and how he worked! Grassi detested people who didn't work. “Mankind,” he said, “is composed of those who work, those who pretend to work, and those who do neither.” He was ready to admit that he belonged in the first class, and it is entirely certain that he did belong there.

  In 1898, the year of the triumph of Ronald Ross, Grassi, knowing nothing of Ross, never having heard of Ross, went back at malaria again. “Malaria is the worst problem Italy has to face! It desolates our richest farms! It attacks millions in our lush lowlands! Why don't you solve that problem?” So the politicians, to Battista Grassi. Then too, the air was full of whispers of the possibility that I don't know how many different diseases might be carried from man
to man by insects. There was that famous work of Theobald Smith, and Grassi had an immense respect for Theobald Smith. But what probably finally set Grassi working at malaria—you must remember he was a very patriotic and jealous man—was the arrival of Robert Koch. Dean of the microbe hunters of the world, Tsar of Science (his crown was only a little battered) Koch had come to Italy to prove that mosquitoes carry malaria from man to man.

  Koch was an extremely grumpy, quiet, and restless man now; sad because of the affair of his consumption cure (which had killed a considerable number of people); restless after the scandal of his divorce from Emmy Fraatz. So Koch went from one end of the world to the other, offering to conquer plagues but not quite succeeding, trying to find happiness and not quite reaching it. His touch faltered a little. . . And now Koch met Battista Grassi, and Grassi said to Robert Koch:

  “There are places in Italy where mosquitoes are absolutely pestiferous—but there is no malaria at all in those places!”

  “Well—what of it?”

  “Right off, that would make you think mosquitoes had nothing to do with malaria,” said Battista Grassi.

  “So?”. . . Koch was enough to throw cold water on any logic!

  “Yes—but here is the point,” persisted Grassi, “I have not found a single place where there is malaria—where there aren't mosquitoes too!”

  “What of that?”

  “This of that!” shouted Battista Grassi. “Either malaria is carried by one special particular bloodsucking mosquito, out of the twenty or forty kinds of mosquitoes in Italy—or it isn't carried by mosquitoes at all!”

  “Hrrrm-p,” said Koch.

  So Grassi made no hit with Robert Koch, and so Koch and Grassi went their two ways, Grassi muttering to himself: “Mosquitoes—without malaria. . . but never malaria—without mosquitoes! That means one special kind of mosquito! I must discover the suspect. . .”

  That was the homely reasoning of Battista Grassi. He compared himself to a village policeman trying to discover the criminal in a village murder. “You wouldn't examine the whole population of a thousand people one by one!” muttered Grassi. “You would try to locate the suspicious rogues first. . .”

  His lectures for the year 1898 at the University of Rome over, he was a conscientious man who always gave more lectures than the law demanded, he needed a rest, and on the 15th of July he took it. Armed with sundry fat test-tubes and a notebook, he sallied out from Rome to those low hot places and marshy desolations where no man but an idiot would go for a vacation.

  Unlike Ross, this Grassi was a mosquito expert besides everything else that he was. His eyes—so red-rimmed and weak—were exceedingly sharp at spotting every difference between the thirty-odd different kinds of mosquitoes that he met. He went around with the fat test-tube in his hand, his ear cocked for buzzes. The buzz dies away as the mosquito lights. She has lit in an impossible place. Or she has lit in a disgusting place. No matter, Battista Grassi is up behind her, pounces on her, claps his fat test-tube over her, puts a grubby thumb over the mouth of the test-tube, paws over his prize and pulls her apart, scrawls little cramped pothooks in his notebook. That was Battista Grassi, up and down and around the nastiest places in Italy all that summer.

  So it was he cleared a dozen or twenty different mosquitoes of the suspicion of the crime of malaria—he was always finding these beasts in places where there was no malaria. He ruled out two dozen different kinds of gray mosquitoes and brindled mosquitoes, that he found anywhere—in saloons and bedrooms and the sacristies of cathedrals, biting babies and nuns and drunkards. “You are innocent!” shouted Battista Grassi at these mosquitoes. “For where you are none of these nuns or babies or drunkards suffers from malaria!”

  You will grant this was a most outlandish microbe hunting of Grassi's. He went around making a nuisance of himself. He insinuated himself into the already sufficiently annoyed families of those hot malarious towns. He snooped annoyingly into the affairs of these annoyed families: “Is there malaria in your house?. . . Has there ever been malaria in your house?. . . How many have never had malaria in your house. . . how many mosquito bites did your sick baby have last week?. . . What kind of mosquitoes bit him?” He was utterly without a sense of humor. And he was annoying.

  “No,” the indignant head of the house might tell him, “we suffer from malaria—but we are not bothered by mosquitoes!” Battista Grassi would never take his word for that. He snouted into pails and old crocks in the back yards. He peered beneath tables and behind sacred images and under beds. He even discovered mosquitoes hiding in shoes under those beds. . .

  So it was—it is most fantastical—that Battista Grassi went more than two-thirds of the way to solving this puzzle of how malaria gets from sick men to healthy ones before he had ever made a single experiment in his laboratory! For, everywhere where there was malaria, there were mosquitoes. And such mosquitoes! They were certainly a very special definite sort of blood-sucking mosquito Grassi found.

  “Zan-za-ro-ne, we call that kind of mosquito,” the householders told him.

  “Always, where the ”zan-za-ro-ne“ buzzed, there Grassi found deep flushed faces on rumpled beds, or faces with chattering teeth going towards those beds. Always where that special and definite mosquito sang at twilight, Grassi found fields waiting for some one to till them, and from the houses of the little villages that sat in these fields, he saw processions emerging, and long black boxes. . .

  There was no mistaking this mosquito, zanzarone, once you had spotted her; she was a frivolous gnat that flew up from the marshes towards the lights of the towns; she was an elegant mosquito proud of four dark spots on her light brown wings; she was not a too dignified insect who sat in an odd way with the tail-end of her body sticking up in the air [that was one way he could spot her, for the Culex mosquitoes drooped their tails]; she was a brave blood-sucker who thought: “The bigger they are the more blood I get out of them!” So zanzarone preferred horses to men and men to rabbits. That was zanzarone, and the naturalists had given her the name Anopheles claviger many years before. Anopheles claviger! This became the slogan of Battista Grassi. You can see him, shuffling along behind lovers in the dusk, making fists of his fingers to keep himself from pouncing on the zanzarone who made meals off their regardless necks. . . You can see this Grassi, sitting in a stagecoach with no springs, oblivious to bumps, deaf to the chatter of his fellow-passengers, with absent eyes counting the Anopheles claviger he had discovered—with delight—riding on the ceiling of the wagon in which he journeyed from one utterly terrible little malarious village to another still more cursed.

  “I'll try them on myself!” Grassi cried. He went up north to his home in Rovellasca. He taught boys how to spot the anopheles mosquito. The boys brought boxes full of these she-zanzarone from towns where malaria raged. Grassi took these boxes to his bedroom, put on his night shirt, opened the boxes, crawled into bed—but curse it! not one of the zanzarone bit him. Instead they flew out of his room and bit Grassi's mother, “fortunately without ill effect!”

  Then Grassi went back to Rome to his lectures, and on September 28th of 1898, before ever he had done a single serious experiment, he read his paper before the famous and ancient Academy of the Lincei: “It is the anopheles mosquito that carries malaria if any mosquito carries malaria. . . ” And he told them he was suspicious of two other brands of mosquitoes—but that was absolutely all, out of the thirty or forty different tribes that infected the low places of Italy.

  Then came an exciting autumn for Battista Grassi and an entertaining autumn for the wits of Rome, and a most important autumn for mankind. Besides all that it was a most itchy autumn for Mr. Sola, who for six years had been a patient of Dr. Bastianelli in the Hospital of the Holy Spirit, high up on the top floor of this hospital that sat on a high hill of Rome. Here zanzarone never came. Here nobody ever got malaria. Here was the place for experiments. And here was Mr. Sola, who had never had malaria, every twist and turn of whose health Dr. Bastianelli kn
ew, who told Battista Grassi that he would not mind being shut up with three different brands of hungry she-mosquitoes every night for a month.

  Grassi and Bignami and Bastianelli started off, strangely enough, with those two minor mosquito suspects—those two culexes that Grassi had discovered always hanging around malarious places along with the zanzarone. . . They tortured Mr. Sola each night with hundreds of these mosquitoes. They shut poor Mr. Sola up in that room with those devils and turned off the light. . .

  Nothing happened. Sola was a tough man. Sola showed not a sign of malaria.

  (It is not clear why Grassi did not start off by loosing his zanzarone at this Mr. Sola.)

  Maybe it was because Robert Koch had laughed publicly at this idea of the zanzarone—Grassi does admit that discouraged him.

  But, one fine morning, Grassi hurried out of Rome to Moletta and came back with a couple of little bottles in which buzzed ten fine female anopheles mosquitoes. That night Mr. Sola had a particularly itchy time of it. Ten days later this stoical old gentleman shook horribly with a chill, his body temperature shot up into a high fever—and his blood swarmed with the microbes of malaria.

  “The rest of the history of Sola's case has no interest for us,” wrote Grassi, “but it is now certain that mosquitoes can carry malaria, to a place where there are no mosquitoes in nature, to a place where no case of malaria has ever occurred, to a man who has never had malaria—Mr. Sola!”