6
Compared to this sly murderer the bacillus of anthrax had been reasonably easy to discover—it was a large bug as microbes go, and the bodies of sick animals were literally alive with anthrax germs when the beasts were about to die. But this tubercle germ—if indeed there was such a creature—was a different matter. Many searchers were looking in vain for it. Leeuwenhoek, with his sharpest of all eyes, would never have found it even if he had looked at a hundred sick lungs; Spallanzani's microscopes would not have been good enough to have revealed this sly microbe; Pasteur, searcher that he was, had neither the precise methods of searching, nor, perhaps, the patience, to lay bare this assassin.
All that was known about tuberculosis was that it must be caused by some kind of microbe, since it could be transmitted from sick men to healthy animals. An old Frenchman, Villemin, had pioneered in this work, and Cohnheim, the brilliant professor of Breslau, had found that he could give tuberculosis to rabbits—by putting a bit of the consumptive's sick lung into the front chamber of a rabbit's eye. Here Cohnheim could watch the little islands of sick tissue—the tubercles—spread and do their deadly work; it was a strange clever experiment that was like looking through a window at a disease growing. . .
Koch had studied Cohnheim's experiments closely. “This is what I need,” he meditated. “I may not use human beings for experimental animals, but now I can give the disease, whenever I wish, to animals. . . here is a real chance to study it, handle it, to look for the microbe that must cause it. . . there must be a microbe there. . .”
So Koch set to work—he did everything with a cold system that gives one the shivers when one reads his scientific reports—and he got his first consumptive stuff from a powerful man, a laborer aged thirty-six. This man had been superbly healthy three weeks before, when all at once he began to cough, little pains shot through his chest, his body seemed literally to melt away. Four days after this poor fellow entered the hospital, he was dead, riddled with tubercles—every organ was peppered with little grayish-yellow, millet-seed-like specks—
With this dangerous stuff Koch set to work, alone, for Loeffler had set out to track down the microbe of diphtheria and Gaffky was busy trying to find the sub-visible author of typhoid fever. Koch, meanwhile, crushed the yellowish tubercles from the body of the dead man between two heated knives; he ground these granules up and delicately, with a little syringe, injected them into the eyes of numerous rabbits and under the skins of flocks of foolish guinea-pigs. He put these beasts in clean cages and tended them lovingly. And while he waited for his creatures to develop signs of the consumption, he began to peer with his most powerful microscope through the sick tissues that he had taken from the body of the dead workman.
For days he saw nothing. His best lenses, that magnified many hundred times, showed him only the dead ruins of what had once been good healthy lung or liver. “If there is a tubercle microbe, he is such a sneaky fellow that I won't be able, perhaps, to see him in his native state. But I can try painting the tissue with a powerful dye—that may make this bug stand out. . .”
Day after day, Koch set about staining the stuff from the dead workman brown and blue and violet and most of the colors of the rainbow. Carefully, dipping his hands in the germ-killing bichloride of mercury after almost every move—blackening and wrinkling them with it—he smeared the perilous material from the tubercles on thin clean bits of glass and kept these pieces of glass for hours in a strong blue dye. . .
Then one morning he took his specimens out of their bath of stain, and put them under his lens, and focussed his microscope and out of the gray mist a strange picture untangled itself. Lying among the shattered diseased lung cells were curious masses of little, infinitely thin bacilli—blue colored rods—so slim that he could not guess their size, and they were less than a fifteen-thousandth of an inch long.
“Ah! they are pretty,” he muttered. “They're not straight like the anthrax bugs. . . they have little bends and curves in them. Wait! here are whole bunches of them. . . like cigarettes in a pack—Heh! here is one lone devil inside a lung cell. . . I wonder. . . have I found him—that tubercle bug, already?”
Koch went on, precisely, with that efficiency of his, to staining tubercles from every part of the workman's body, and everywhere his blue dye showed up these same slender crooked bacilli—strange creatures unlike any he had seen in all the thousands of animals or men, diseased or healthy, into whose insides he had pried. And now, sorry things began to happen to his inoculated guinea-pigs and rabbits. The guinea-pigs began to huddle disconsolately in the corners of their cages; their sleek coats ruffled and their bouncing little bodies began to fall away until they were sad bags of bones. They were feverish, their cavortings stopped and they looked listlessly at their fine carrots and their fragrant meals of hay—and one by one they died. And as these unconscious martyrs died—for Koch's mad curiosity and for suffering men—the little microbe hunter pinned them down on his postmortem board and soaked their sick hair with bichloride of mercury and precisely and with breathless care cut them open with sterile knives.
And inside these poor beasts Koch found the same kind of grayish-yellow sinister tubercles that had filled the body of the workman. Into the baths of blue stain on his eternal strips of glass Koch dipped them—and everywhere, in every one, he found the same terrible curved sticks that had jumped into his astounded gaze when he had stained the lung of the dead man.
“I have it!” he whispered, and called the busy Loeffler and the faithful Gaffky from their own spyings on other microbes. “Look!” Koch cried. “One little speck of tubercle I put into this beast six weeks ago—there could not have been more than a few hundred of those bacilli in that small bit—and now they've grown into billions! What devils they are, those germs—from that one place in the guinea-pig's groin they have sneaked everywhere into his body, they have gnawed—they have grown through the walls of his arteries. . . the blood has carried them into his bones. . . into the farthest corner of his brain. . .”
Now he went to hospitals everywhere in Berlin, and begged the bodies of men or women that had died of consumption, he spent dreary days in dead houses and every evening before his microscope in his laboratory where the stillness was broken only by the eerie purrings and scurryings of guinea-pigs. He injected the sick tissue from the wasted bodies of consumptives who had died, into hundreds of guinea-pigs, into rabbits and three dogs, thirteen scratching cats, ten flopping chickens and twelve pigeons. He didn't stop with these wholesale insane inoculations but shot the same kind of deadly cheesy stuff into white mice and rats and field mice and into two marmots. Never in microbe hunting has there been such appalling thoroughness.
“Ach! this is a little hard on the nerves, this work,” he muttered (thinking, perhaps of the lightning move of the paw of one of his cats jabbing the germ-filled syringe needle into his own hand). For Koch, hunting his invisible foes alone, there were so many disagreeable and always imminent possibilities of excitement—of something tragically worse than mere excitement. . .
But the hand of this completely unheroic looking little microbe hunter never slipped, it just grew drier and more wrinkled and blacker from its incessant baths in the bichloride of mercury—that good bichloride, with which in those old days the groping microbe hunters used to swab down everything, including their own persons. Then, week by week, in all of Koch's meaouwing, crowing, barking, clucking menagerie of beasts those small curved bacilli grew into their relentless millions—and one by one the animals died, and gave eighteen-hour-days of work to Robert Koch in post-mortems and blear-eyed peerings through the microscope.
“It is only when a man or beast has tuberculosis that I can find these blue-stained rods, these bacilli,” Koch told Loeffler and Gaffky. “In healthy animals—I have looked, you know, at hundreds of them—I never find them.”
“That means, without doubt, that you have discovered the bacillus that is the cause, Herr Doktor—”
“No—not
yet—what I have done might make Pasteur sure, but I am not at all convinced yet. . . I have to get these bacilli out of the bodies of my dying animals now. . . grow them on our beef broth jelly, pure colonies of these microbes I must get, and cultivate them for months, away from any living creature. . . and then, if I inoculate these cultivations into good healthy animals, and they get tuberculosis. . . ” and Koch's sober wrinkled face smiled for a moment. Loeffler and Gaffky, ashamed of their jumping at conclusions, went back awed to their own searchings.
Testing every possible combination that his head could invent, Koch set out to try to grow his bacilli pure on beef-broth jelly. He made a dozen different kinds of good soup for them, he kept his tubes and bottles at the temperature of the room and the temperature of a man's body and the temperature of fever. He cleverly used the sick lungs of guinea-pigs that teemed with bacilli, lungs that held no other stray microbes which might over-grow and choke out those delicate germs which he was sure must be the authors of consumption. The stuff from these lungs he planted dangerously into hundreds of tubes and bottles, but all this work ended in—nothing. In brief, those slim bacilli that grew like weeds in tropic gardens in the bodies of his sick animals, those microbes that swarmed in millions in sick men, those bacilli turned up their noses—that is, they would have if they had been equipped with noses—at the good soups and jellies that Koch cooked for them. It was no go!
But one day a reason for his failures popped into Koch's head: “The trouble is that these tubercle bacilli will only grow in the bodies of living creatures—they are maybe almost complete parasites—I must fix a food for them that is as near as possible like the stuff a living animal's body is made of!”
So it was that Koch invented his famous food—blood-serum jelly—for microbes that are too finicky to grow on common provender. He went to string-butchers and got the clear straw-colored serum from the clotted blood of freshly slaughtered healthy cattle and carefully heated this fluid to kill all the stray microbes that might have fallen into it. Delicately he poured this serum into each one of dozens of narrow test-tubes, and placed these on a slant so that there would be a long flat surface on which to smear the sick consumptive tissues. Then ingeniously he heated each tube just hot enough to make the serum set, on a slant, into a clear beautiful jelly.
That morning a guinea-pig, sadly riddled with tuberculosis, had died. He dissected out of it a couple of the grayish yellow tubercles, and then, with a wire of platinum he streaked bits of this bacillus-swarming stuff on the moist surface of his serum jelly, on tube after tube of it. Then, with that drawing in and puffing out of breath that come after a nasty piece of work, well done, Koch took his tubes and put them in the oven—at the exact temperature of a guinea-pig's body.
Day after day Koch hurried in the morning to his incubating oven, and took out his tubes and held them close to his gold-rimmed glasses, and saw—nothing.
“Well, I have failed again,” he mumbled—it was the fourteenth day after he had planted his consumptive stuff—“every other microbe I have ever grown multiplies into large colonies in a couple of days, but here, confound it—there is nothing, nothing. . .”
Any other man would have pitched these barren disappointing serum-tubes out, but at this stubbly-haired country doctor's shoulder his familiar demon whispered: “Wait—be patient, my master—you know that tubercle germs sometimes take months, years to kill men. Maybe too they grow very slowly in the serum tubes.” So Koch did not pitch the tubes out, and on the morning of the fifteenth day he came back to his incubator—to find the velvety surface of the serum jelly covered with tiny glistening specks! Koch reached a trembling hand for his pocket lens, clapped it to his eye and peered at one tube after another, and through his lens these glistening specks swelled out into dry tiny scales. . .
In a daze Koch pulled the cotton plug out of one of his tubes, mechanically he flamed its mouth in the sputtering blue fire of the Bunsen burner, with a platinum wire he picked off one of these little flaky colonies—they must be microbes—and not knowing how or what, he got them before his microscope. . .
Then he knew that he had got to a warm inn on the stony road of his adventure—here they were, countless myriads of these same bacilli, these crooked rods that he had first spied in the lung of the dead workman. They were motionless but surely multiplying and alive—they were delicate and finicky about their food and feeble in size, but more savage than hordes of Huns and more murderous than ten thousand nests of rattlesnakes.
Now Koch, in taut intent months, confirmed his first success—he went after proving it with a patience and a detail that made me sick of his everlasting thoroughness and prudence as I read the endlessly multiplied experiments in his classic report on tuberculosis—from consumptive monkeys and consumptive oxen and consumptive guinea-pigs Koch grew forty-three different families of these deadly rods on his slanted tubes of serum jelly!
And only from animals sick or dying of tuberculosis, could he grow them. For months he nursed these wee murderers along, planting them from one tube to another—with marvelous watchfulness he kept all other chance microbes away from them.
“Now I must shoot these bacilli—these pure cultivations of my bacilli—into healthy guinea-pigs, into all kinds of healthy animals. If then these creatures get tuberculosis, I shall know that my bacilli are necessarily and beyond all doubt the cause!”
That man with the terrible single-mindedness of a maniac driven by a fixed idea changed his laboratory into the weirdest kind of zoo. He became grouchy to every one—to curious visitors he was a sarcastic, spiteful little German ogre. Alone he sterilized batteries of shining syringes and shot the crinkly masses of microbes from the cultivations in his serum-jelly tubes—he injected these bacilli ground up in a little pure water into guinea-pigs and rabbits and hens and rats and mice and monkeys. “That's not enough!” he growled, “I'll try some animals that never are known to have tuberculosis naturally.” So he ranged abroad and gathered to his laboratory and injected his beloved terrible bacilli into tortoises, sparrows, five frogs and three eels.
Insanely Koch completed this most fantastic test by sticking his microbes from the serum cultivation into—a goldfish!
Days dragged by, weeks passed, and every day Koch walked into his workshop in the morning and made straight for the cages and jars that held these momentous animals. The goldfish continued to open and shut his mouth and swim placidly about in his round-bellied bowl. The frogs croaked unconcernedly and the eels kept all of their slippery liveliness; the tortoise now and then stuck his head out of his shell and seemed to wink an eye at Koch as if to say: “Your tubercle bugs are food for me—give me some more.”
But while his injections worked no harm to these creatures, that do not in the course of nature get consumption anyway—at the same time the guinea-pigs began to droop, to lie pitifully on their sides, gasping. One by one they died, their bodies wasting terribly into tubercles. . .
Now Koch had forged the last link of the chain of his experiments and was ready to give his news to the world: The bacillus, the true cause of tuberculosis, had been trapped, discovered! When suddenly he decided there was one more thing to do.
“Human beings surely must catch these bacilli by inhaling them, in dust, or from the coughing of people sick with consumption. I wonder, will healthy animals be infected that way too?” At once Koch began to devise ways of doing this experiment—it was a nasty job. “I'll have to spray the bacilli from my cultivations at the animals,” he pondered. But this was a more serious business than turning ten thousand murderers out of jail. . .
Like the good hunter that he was, he took a chance with the dangers that he couldn't avoid. He built a big box and put guinea-pigs and mice and rabbits inside it and set this box in the garden. Then through the window he ran a lead pipe that opened in a spray nozzle inside the box, and for three days, for half an hour each day, he sat in his laboratory, pumping at a pair of bellows that shot a poisonous mist of bacilli into t
he box—to be breathed by the cavorting beasts inside it.
In ten days three of the rabbits were gasping, fighting for that precious air that their sick lungs could no longer give them. In twenty-five days the guinea-pigs had done their humble work—one and all they were dead, of tuberculosis.
Koch told nothing of the ticklish job it was to take these beasts out of their germ-soaked box—if I had been in his place I would rather have handled a boxful of boa-constrictors—and he makes no mention of how he disposed of this little house whose walls had been wet with this so-deadly spray. What chances for making heroic flourishes were missed by this quiet Koch!
7
On the twenty-fourth of March in 1882 in Berlin there was a meeting of the Physiological Society in a plain small room made magnificent by the presence of the most brilliant men of science in Germany. Paul Ehrlich was there and the most eminent Professor Rudolph Virchow—who had but lately sniffed at this crazy Koch and his alleged bacilli of disease—and nearly all of the famous German battlers against disease were there.
A bespectacled wrinkled small man rose and put his face close to his papers and fumbled with them. The papers quivered and his voice shook a little as he started to speak. With an admirable modesty Robert Koch told these men the plain story of the way he had searched out the invisible assassin of one human being out of every seven that died. With no oratorical raisings of his voice he told these disease fighters that the physicians of the world were now able to learn all of the habits of this bacillus of tuberculosis—this smallest but most savage enemy of men. Koch recited to them the lurking places of this slim microbe, its strengths and weaknesses, and he showed them how they might begin the fight to crush, to wipe out this sub-visible deadly enemy.
Microbe Hunters Page 14
