Microbe Hunters

by Paul De Kruif

  The devotion of the workers in his laboratory was amazing. They let him feed them virulent cholera bacilli (even one of those pretty inspirational girls swallowed them!) to prove that the blood has nothing to do with our immunity to cholera. For years—he himself said that it was an insanity of his—he was fond of toying with the lives of his researching slaves, and the only thing that excused him was his perfect readiness to risk death along with them. He swallowed more tubes of cholera bacilli than any of them. In the midst of this dangerous business, one of the assistants, Jupille, became violently sick with real Asiatic cholera and Metchnikoff's remorse was immoderate. “I shall never survive the death of Jupille!” he moaned, and Olga, that good wife, had to be on her guard day and night to keep her famous husband from one of his (always fruitless) attempts at suicide. At the end of these strange experiments, Metchnikoff jabbed needles into the arms of the survivors, drew blood from them, and triumphantly found that this blood did not protect guinea-pigs from doses of virulent cholera germs. How he hated the idea of blood having any importance! “Human cholera gives us another example,” he wrote, “of a malady whose cure cannot be explained by the preventive properties of the blood.”

  When some more than ordinarily independent student would come whispering to him that he had discovered a remarkable something about blood, Metchnikoff became magnificent like Moses coming down off Mt. Sinai—searchers for mere truth had a bad time in that laboratory, and you can imagine the great dauntless champion of phagocytes ordering a dissenter from his theory to be burned, and then weeping inconsolably over him afterwards. But, just the same, Metchnikoff—so great was the number of experiments made by an always changing crowd of eager experimenters in his laboratory—this Metchnikoff was partly responsible for the discovery of some of the most astounding virtues of blood. For, in the midst of his triumphs, Jules Bordet came to work with the master. This Bordet was the son of the schoolmaster of the village of Soignies in Belgium. He was timid, he seemed insignificant, he had careless ways and water-blue, absent-minded eyes—eyes that saw things nobody else was looking for. Bordet set to work there, and right in the shadow of the master's beard, while the walls shook with the slogan “Phagocytes!”—the Belgian pried into the mystery of how blood kills germs; he laid the foundation for those astounding delicate tests which tell whether blood is human blood, in murder cases. It was here too, that Bordet began the work which led, years later, to the famous blood test for syphilis—the Wassermann reaction. Metchnikoff was often annoyed with Bordet, but he was proud of him too, and whenever Bordet found anything in blood that was harmful to microbes, and might help to make people immune to them, Metchnikoff consoled himself by inventing more or less accurate experiments which showed that these microbe-killing things came from the phagocytes, after all. Bordet did not remain long in Metchnikoff's laboratory. . .

  Toward the end of the nineteenth century, when romantic microbe hunting began to turn into a regular profession, recruited from good steady law-abiding young doctors who were not prophets or reckless searchers—in those days Metchnikoff's bitter trials with people who didn't believe him began to be less terrible. He received medals and prizes of money, and even the Germans clapped their hands and were respectful when he walked majestically into some congress. A thousand searchers had spied phagocytes in the act of gobbling harmful germs—and although that did not explain at all why one man dies from an attack of pneumonia microbes, while another breaks into a sweat and gets better—just the same there is no doubt that pneumonia germs are sometimes eaten and so got rid of by phagocytes. So Metchnikoff, after you discount his amazing illogic, his intolerance, his bullheadedness, really did discover a fact which may make life easier for suffering mankind. Because, some day, a dreamer, an experimenting genius like the absent-minded Bordet may come along—and he may solve the riddle of why phagocytes sometimes gobble germs and sometimes do not—he might even teach phagocytes always to eat them. . .

  7

  At last Metchnikoff began really to be happy. His opponents were partly convinced, and partly they stopped arguing with him because they found it was no use—he could always experiment more tirelessly than they, he could talk longer, he could expostulate more loudly. So Metchnikoff, at the beginning of the twentieth century, sat down to write a great book on all that he had found out about why we are immune. It was an enormous treatise you would think it would take a lifetime to write. It was written in a style Flaubert might have envied. He made every one of the ten thousand facts in it vivid, and every one of them was twisted prettily to prove his point. It is a strange novel with a myriad of heroes—the wandering cells, the phagocytes of all the animals of the earth.

  His fame made him take a real delight in being alive. Twenty years before, detesting the human race, sorry for himself, and hating life, he had told Olga: “It is a crime to have children—no human being should consciously reproduce himself.” But now that he had begun to take delight in existence, the children of Sèvres, the suburb where he lived, called him “Grandpa Christmas” as he patted their heads and gave them candy. “Life is good!” he told himself. But how to hang onto it, now that it was slipping away so fast. In only one way, of course—by science!

  “Disease is only an episode!” he wrote. “It is not enough to cure (he had discovered no cures). . . it is necessary to find out what the destiny of man is, and why he must grow old and die when his desire to live is strongest.” Then Metchnikoff abandoned work on his dead phagocytes and set out to found fantastic sciences to explain man's destiny, and to avoid it. To one of these, the science of old age, he gave the sonorous name “Gerontology,” and he gave the name “Thanatology” to the science of death. What awful sciences they were; the ideas were optimistic; the observations he made in them were so inaccurate that old Leeuwenhoek would have turned over in his grave had he known about them; the experiments Metchnikoff made, to support these sciences, would have caused Pasteur to foam with indignation that he had ever welcomed this outlandish Russian to his laboratory. And yet—and yet—the way really to prevent one of the most hideous microbic diseases came out of them. . .

  Metchnikoff dreaded the idea of dying but knew that he and everybody else would have to—so he set out to devise a hope (there was not one particle of science in this) for an easy death. Somewhere in his vast hungry readings, he had run across the report of two old ladies who had become so old that they felt no more desire for life—they wanted to die, just as all of us want to go to sleep at the end of a hard day's work. “Ha!” cried Metchnikoff, “that shows that there is an instinct for death just as there is an instinct for sleep! The thing to do is to find a way to live long enough in good health until we shall really crave to die!”

  Then he set out on a thorough search for more of such lucky old ladies, he visited old ladies' homes, he rushed about questioning old crones, with their teeth out, who were too deaf to hear him. He went all the way from Paris to Rouen to interview (on the strength of a newspaper rumor) a dame reported to be a hundred and six. But, alas, all of the oldsters he talked to were strong for life, he never found any one like the two legendary old ladies. Just the same he cried: “There is a death instinct!” Contrary facts never worried him.

  He studied old age in animals; and people were always sending him gray-haired dogs and dilapidated ancient cats; he published a solemn research on why a superannuated parrot lived to be seventy. He owned an ancient he-turtle, who lived in his garden, and Metchnikoff was overjoyed when this venerable beast—at the great age of 86—mated with two lady turtles and became the father of broods of little turtles. He dreaded the passing of the delights of love, and exclaimed, remembering his turtle: “Senility is not so profoundly seated as we suppose!”

  But to push back old age? What is at the bottom of it? A Scandinavian scientist, Edgren, had made a deep study of the hardening of the arteries—that was the cause of old age, suggested Edgren, and among the causes of the hardening of the arteries were the drinking of alcoh
ol, syphilis, and certain other diseases.

  “A man is as old as his arteries, that is true,” muttered Metchnikoff, and he decided to study the riddle of how that loathsome disease hardens the arteries. It was in 1903. He had just received a prize of five thousand francs, and Roux—who, though so different, so much more the searcher, had always stuck by this wild Metchnikoff—Roux had got the grand Osiris prize of one hundred thousand francs. Never were there two men so different in their ways of doing science, but they were alike in caring little for money, and together they decided to use all of these francs—and thirty thousand more which Metchnikoff had wheedled out of some rich Russians—to study that venereal plague, to attempt to give it to apes, to try to discover its then mysterious virus, to prevent it, cure it if possible. And Metchnikoff wanted to study how syphilis hardened the arteries.

  So they bought apes with this money. French governors in the Congo sent black boys to scour the jungles for them, and presently large rooms at the Pasteur Institute were a-chatter with chimpanzees and orang-outangs, and the cries of these were drowned out by the shrieking of the sacred monkey of the Hindoos, and the caterwaulings of the comical little Macacus cynemolgus.

  Almost at once Roux and Metchnikoff made an important find; their experiments were ingenious and they had about them a certain tautness and clearness that was strangely un-Metchnikoffian. Their laboratory began to be the haunt of unfortunate men who had just got syphilis; from one of these they inoculated an ape—and the very first experiment was a success. The chimpanzee developed the disease. From then on, for more than four years they toiled, transmitting the diseases from one ape to another, looking for the sneaking slender microbe but not finding it, trying to find ways to weaken the virus—as Pasteur had done with the unknown germ of rabies—in order to discover a preventive vaccine. Their monkeys died miserably of pneumonia and consumption, they got loose and ran away. While Metchnikoff, not too deftly, scratched the horrible virus into them, the apes bit him and scratched him back—and then Metchnikoff did a strange and clever experiment. He scratched a little syphilitic virus into the ear of an ape, and twenty-four hours later he cut off that ear! The ape never showed one sign of the disease in any other part of his body. . .

  “That means,” cried Metchnikoff, “that the germ lingers for hours at the spot where it gets into the body—now, as in men we know exactly where the virus gets in, maybe we can kill it before it ever spreads—since in this disease we know just when it gets in, too!”

  So Metchnikoff, with Roux always being careful and insisting upon good check experiments—so Metchnikoff, after all of his theorizing about why we are immune, performed one of the most profoundly practical of all the experiments of microbe hunting. He sat himself down and invented the famous calomel ointment—that now is chasing syphilis out of armies and navies the world over. He took two apes, inoculated them with the syphilitic virus fresh from a man, and then, one hour later, he rubbed the grayish ointment into that scratched spot on one of his apes. He watched the horrid signs of the disease appear on the unanointed beast, and saw all signs of the disease stay away from the one that had got the calomel.

  Then for the last time Metchnikoff's strange insanity got hold of him. He forgot his vows and induced a young medical student, Maisonneuve, to volunteer to be scratched with syphilis from an infected man. Before a committee of the most distinguished medical men of France, this brave Maisonneuve stood up, and into six long scratches he watched the dangerous virus go. It was a more severe inoculation than any man would ever get in nature. The results of it might make him a thing for loathing, might send him, insane, to his death. . . For one hour Maisonneuve waited, then Metchnikoff, full of confidence, rubbed the calomel ointment into the wounds—but not into those which had been made at the time on a chimpanzee and a monkey. It was a superb success, for Maisonneuve showed never a sign of the ugly ulcer, while the simians, thirty days afterwards, developed the disease—there was no doubt about it.

  Moralists—and there were many doctors among these, mind you—raised a great clamor against these experiments of Metchnikoff. “It will remove the penalty of immorality!” said they, “to spread abroad such an easy and a perfect means of prevention!” But Metchnikoff only answered: “It has been objected that the attempt to prevent the spread of this disease is immoral. But since all means of moral prophylaxis have not prevented the great spread of syphilis and the contamination of innocents, the immoral thing is to restrain any available means we have of combating this plague.”

  8

  Meanwhile he was scheming and groping about and having dreams about other things that might cause the arteries to harden, and suddenly he invented another cause—surely no one can say he discovered ill—“autointoxication, poisoning from the wild, putrefying bacilli in our large intestines—that is surely a cause of the hardening of the arteries, that is what helps us to grow old too soon!” he cried. He devised chemical tests—what awful ones they were—that would show whether the body was being poisoned from the intestine. “We would live much longer,” he said, “if we had no large intestine, indeed, two people are on record, who had their large intestine cut out, and live perfectly well without it.” Strange to say, he did not advocate cutting the bowels out of every one, but he set about thinking up ways of making things there uncomfortable for the “wild bacilli.”

  His theory was a strange one, and caused laughter and jeers and he began to get into trouble again. People wrote in, reminding him that elephants had enormous large intestines but lived to be a hundred in spite of them; that the human race, in spite of its large intestine, was one of the longest-lived species on earth. He engaged in vast obscene arguments about why evolution has allowed animals to keep a large intestine—then suddenly he hit on his great remedy for auto-intoxication. There were villages in Bulgaria where people were alleged to live to be more than a hundred. Metchnikoff didn't go down there to see—he believed it. These ancient people lived principally upon sour milk, so went the story. “Ah! there's the explanation,” he muttered. He put the youngsters in his laboratory to studying the microbe that made milk sour—and in a little while the notorious Bulgarian bacillus made its bow in the rank of patent medicines.

  “This germ,” explained Metchnikoff, “by making the acid of sour milk, will chase the wild poisonous bacilli out of the intestine.” He began drinking huge draughts of sour milk himself, and later, for years, he fed himself cultivations of the Bulgarian bacillus. He wrote large books about his new theory and a serious English journal acclaimed them to be the most important scientific treatises since Darwin's “Origin of Species.” The Bulgarian bacillus became a rage, companies were formed, and their directors grew rich off selling these silly bacilli. Metchnikoff let them use his name (though Olga insists he never made a franc from that) for the label.

  For nearly twenty years Metchnikoff austerely lived to the letter of his new theory. He neither drank alcoholic drinks nor did he smoke. He permitted himself no debaucheries. He was examined incessantly by the most renowned specialists of the age. His rolls were sent to him in separate sterilized paper bags so that they would be free from the wild, auto-intoxicating bacilli. He constantly tested his various juices and excretions. In those years he got down untold gallons of sour milk and swallowed billions of the beneficent bacilli of Bulgaria. . .

  And he died at the age of seventy-one.

  8. THEOBALD SMITH:

  Ticks and Texas Fever

  1

  It was Theobald Smith who made mankind turn a corner. He was the first, and remains the captain of American microbe hunters. He poked his nose—following the reasoning of some plain farmers—around a sharp turn and came upon amazing things; and now this history tells what Smith saw and what the trail-breakers who came after him found.

  “It is in the power of man to make parasitic maladies disappear from the face of the globe!” So promised Pasteur, palsied but famous after his fight with the sicknesses of silk-worms. He promised that, you
remember, with a kind of enthusiastic vehemence, making folks think they might be rid of plagues by a year after next at the latest. Men began to hope and wait. . . They cheered as Pasteur invented vaccines—marvelous these were but not what you would call microbe-exterminators. Then Koch came, to astound men by his perilous science of finding the tubercle bacillus, and, though Koch promised little, men remembered Pasteur's prophecy and waited for consumption to vanish. . . Years went by while Roux and Behring battled bloodily to scotch the poison of diphtheria; mothers crooned hopeful songs into the ears of their children. . . Some men giggled, but secretly hoped a little too, that the mighty (albeit windy) Metchnikoff might teach his phagocytes to eat up every germ in the world. . . Diseases were getting a bit milder maybe—the reason is still mysterious—but they seemed in no hurry to vanish, and men had to keep on waiting. . .

  Then arose a young man, Theobald Smith, at the opening of the last ten years of the eighteen hundreds, to show why northern cows get sick and die of Texas fever when they go south, and to explain why southern cows, though healthy, go north and trail along with them a mysterious death for northern cattle. In 1893 Theobald Smith wrote his straight, clear report of the answer to this riddle; there was certainly no public horn-tooting about it and the report is now out of print—but that report gave an idea to the swashbuckling David Bruce; it gave hints to Patrick Manson; it set thoughts flickering through the head of the brilliant but indignant Italian, Grassi; that report gave confidence in his dangerous quest to the American Walter Reed and that gang of officers and gallant privates who refused extra pay for the job of being martyrs to research.