Microbe Hunters/Chapter 6

It was to save babies that they killed so many guinea-pigs!

Émile Roux, the fanatical helper of Pasteur, in 1888 took up the tools his master had laid down, and started on searches of his own. In a little while he discovered a strange poison seeping from the bacillus of diphtheria—one ounce of the pure essence of this stuff was enough to kill seventy-five thousand big dogs. A few years later, while Robert Koch was bending under the abuse and curses of sad ones who had been disappointed by his supposed cure for consumption, Emil Behring, the poetical pupil of Koch, spied out a strange virtue, an unknown something in the blood of guinea-pigs. It could make that powerful diphtheria poison completely harmless. . . . These two Emils revived men's hopes after Koch's disaster, and once more people believed for a time that microbes were going to be turned from assassins into harmless little pets.

What experiments these two young men made to discover this diphtheria antitoxin! They went at it frantic to save lives; they groped at it among bizarre butcherings of countless guinea-pigs; in the evenings their laboratories were shambles like the battlefields of old days when soldiers were mangled by spears and pierced by arrows. Roux dug ghoulishly into the spleens of dead children—Behring bumped his nose in the darkness of his ignorance against facts the gods themselves could not have predicted. For each brilliant experiment these two had to pay with a thousand failures.

​But they discovered the diphtheria antitoxin.

They never could have done it without the modest discovery of Frederick Loeffler. He was that microbe hunter whose mustache was so militaristic that he had to keep pulling it down to see through his microscope; he sat working at Koch's right hand in that brave time when the little master was tracking down the tubercle bacillus. It was in the early eighteen eighties, and diphtheria, which several times each hundred years seems to have violent ups and downs of viciousness—diphtheria was particularly murderous then. The wards of the hospitals for sick children were melancholy with a forlorn wailing; there were gurgling coughs foretelling suffocation; on the sad rows of narrow beds were white pillows framing small faces blue with the strangling grip of an unknown hand. Through these rooms walked doctors trying to conceal their hopelessness with cheerfulness; powerless they went from cot to cot—trying now and again to give a choking child its breath by pushing a tube into its membrane-plugged windpipe. . . .

Five out of ten of these cots sent their tenants to the morgue.

Below in the dead house toiled Frederick Loeffler, boiling knives, heating platinum wires red hot and with them lifting grayish stuff from the still throats of those bodies the doctors had failed to keep alive; and this stuff he put into slim tubes capped with white fluffs of cotton, or he painted it with dyes, which showed him, through his microscope, that there were queer bacilli shaped like Indian clubs in those throats, microbes which the dye painted with pretty blue dots and stripes and bars. In nearly every throat he discovered these strange bacilli; he hurried to show them to his master, Koch.

There is little doubt Koch led Loeffler by the hand in this discovery. "There is no use to jump at conclusions," you can hear Koch telling him. "You must grow these microbes pure—then you must inject the cultivations into animals. . . . If those beasts come down with a disease exactly like human diphtheria, then . . ." How could Loeffler have gone wrong, ​with that terribly pedantic, but careful, truth-hunting little czar of microbe hunters squinting at him from behind those eternal spectacles?

One dead child after another Loeffler examined; he poked into every part of each pitiful body; he stained a hundred different slices of every organ; he tried—and quickly succeeded—in growing those queer barred bacilli pure. But everywhere he searched, in every part of each body, he found no microbes—except in the membrane-cluttered throat. And always here, in every child but one or two, he came on those Indian club-shaped rods. “How can these few microbes, growing nowhere in the body but the throat—how can these few germs, staying in that one place, kill a child so quickly?” pondered Loeffler. “But I must follow Herr Koch’s directions!” and he proceeded to shoot the germs of his pure cultivations into the windpipes of rabbits and beneath the skins of guinea-pigs. Quickly these animals died—in two or three days, like a child, or even more quickly—but the microbes, which Loeffler had shot into them in millions, could only be found at the spot where he had injected them. . . . And sometimes there were none to be found even here, or at best a few feeble ones hardly strong enough, you would think, to hurt a flea. . . .

“But how is it these few bacilli—sticking in one little corner of the body—how can they topple over a beast a million times larger than they are themselves?” asked Loeffler.

Never was there a more conscientious searcher than this Loeffler, nor one with less of a wild imagination to liven—or to spoil—his almost automatic exactness. He sat himself down; he wrote a careful scientific paper; it was modest, it was cold, it was not hopeful, it was a most unlawyer-like report reciting all of the fors and againsts on the question of whether or no this new bacillus was the cause of diphtheria. He leaned over backward to be honest—he put last the facts that were against it! “This microbe may be the cause,” you can hear him mumbling as he wrote, “but in a few children dead of diphtheria I could not find these germs . . . none of my inoculated animals ​get paralysis as children do . . . what is most against me is that I've discovered this same microbe—it was vicious against guinea-pigs and rabbits too!—in the throat of a child with never a sign of diphtheria."

He even went so far as to underestimate the importance of his exact fine searching, but at the end of his treatise he gave a clew to the more imaginative Roux and Behring who came after him. A strange man, this Loeffler! Without seeming to be able to make a move to do it himself, he predicted what others must find:

"This bacillus stays on a little patch of dead tissue in the throat of a baby; it lurks on a little point under a guinea-pig's skin; it never swarms in millions—yet it kills! How?

"It must make a poison—a toxin that leaks out of it, sneaking from it to some vital spot in the body. Such a toxin must be found, in the organs of a dead child, in the carcass of a guinea-pig dead of the disease—yes—and in the broth where the bacillus grows so well. . . . The man finding this poison will prove what I have failed to demonstrate." Such was the dream Loeffler put into Roux's head. . . .

Four years later Loeffler's words came true—by what seemed an utterly silly, but what was surely a most fantastical experiment you would have thought could only result in drowning a guinea-pig. What a hectic microbe hunting went on in Paris just then! Pasteur, in a state of collapse after his triumph of the dog bite vaccine, was feebly superintending the building of his million-franc Institute in the Rue Dutot. The wild, half-charlatan Metchnikoff had come out of Odessa in Russia to belch quaint theories about how phagocytes gobble up malignant germs. Pasteurians were packing microscopes in satchels and hurrying to Saigon in Indo-China and to Australia to try to discover microbes of weird diseases that did not exist. Hopefully frantic women were burying Pasteur—he was too ​tired!—under letters begging him to save their children from a dozen horrid diseases.

"If you will," one woman wrote him, "you can surely find a remedy for the horrible disease called diphtheria. Our children, to whom we teach your name as a great benefactor, will owe their lives to you!"

Pasteur was absolutely done up, but Roux—and he was helped by the intrepid Yersin who afterward brilliantly discovered the germ of the black death—set out to try to find a way to wipe diphtheria from the earth. It wasn't a science—it was a crusade, this business. It was full of passion, of purpose; it lacked skillful lying-in-wait, and those long planned artistic ambushes you find in most discoveries. I will not say Émile Roux began his searching because of this pitiful note from that woman—but there is no doubt he worked to save rather than to know. From the old palsied master down to the most obscure bottle wiper, the men of this house in the Rue Dutot were humanitarians; they were saviors—and that is noble!—but this drove them sometimes into strange byways far off the road where you find truth. . . . And in spite of this Roux made a marvelous discovery.

Roux and Yersin went to the Hospital for Sick Children—diphtheria was playing hell with Paris—and here they ran on to the same bacillus Loeffler had found. They grew this microbe in flasks of broth, and did the regular accepted thing first, shooting great quantities of this soup into an assorted menagerie of unfortunate birds and quadrupeds who had to die without the satisfaction of knowing they were martyrs. It wasn't particularly enlightened searching, this, but almost from the tap of the gong, they stumbled on one of the proofs Loeffler had failed to find. Their diphtheria soup paralyzed rabbits! The stuff went into their veins; in a few days the delighted experimenters watched these beasts drag their hind legs limply after them; the palsy crept up their bodies to their front legs and shoulders—they died in a clammy, dreadful paralysis. . . .

​"It hits rabbits just the way it does children," muttered Roux, full of a will to believe—— "This bacillus must be the true cause of diphtheria. . . . I shall find the germ in these rabbits' bodies now!" And he clawed tissues out of a dozen corners of their carcasses; he made cultivations of their spleens and hearts—but never a bacillus! Only a few days before he had pumped a billion or so into them, each of them. Here they were, drawn and quartered, carved up and searched from their pink noses to the white under-side of their tails. And not a bacillus. What had killed them then?

Then Loeffler's prediction flashed over Roux: "It must be the germs make a poison, in this broth, to paralyze and kill these beasts . . ." he pondered.

For a while the searcher came uppermost in him. He forgot about possible savings of babies; he concentrated on vast butcheries of guinea-pigs and rabbits—he must prove that the diphtheria germ drips a toxin out of its wee body. . . . Together with Yersin he began a good unscientific fumbling at experiments; they were in the dark; there were no precedents nor any kind of knowledge to go by. No microbe hunter before them had ever separated a deadly poison (though Pasteur had once made something of a try at it) from the bodies of microbes. They were alone in the dark, Roux and Yersin—but they lighted matches. . . . "The bacilli must pour out a poison into the broth we grow them in—just as they pour it from their membrane in a child's throat into his blood!" Of course that last was not proved.

Then Roux stopped arguing in a circle. He searched. He worked with his hands. It was worse, this fumbling of his, than trying to get a stalled motor to go when you know nothing about internal combustion machinery. He took big glass bottles and put pure microbeless soup into them, and sowed pure cultivations of the diphtheria bacillus in this broth; into the incubating oven went the large-bellied bottles—— "Now we will try separating the germs from the soup in which they grow," said Roux, after the bottle had ripened for four days. ​They rigged up a strange apparatus—it was a filter, shaped like a candle, only it was hollow, and made of fine porcelain that would let the soup through, but so tight-meshed that it would hold the tiniest bacilli back. With tongue-protruding care to keep themselves from being splashed with this deadly stuff, they poured the microbe-teeming broth around the candles held rigid in shiny glass cylinders. They fussed—maybe, or at least I hope so, with the blessed relief of profanity—but the broth wouldn't run through the porcelain. But at last they pushed it through with high air pressure—and finally they breathed easy, arranging little flasks full of a clear, amber-colored filtered fluid (it had never a germ in it) on their laboratory bench.

"This stuff should have the poison in it . . . the filter has held back all the microbes—but this stuff should kill our animals," muttered Roux. The laboratory buzzed with eager animal-boys getting ready the rabbits and guinea-pigs. Into the bellies of these beasts went the golden juice propelled from the syringe by Roux's deft hands. . . .

He became a murderer in his heart, this Émile Roux, and in his head as he came down to the laboratory each morning were half-mad wishes for the death of his beasts. "The stuff should be hitting them by now," you can hear him growling to Yersin, but they looked in vain for the ruffled hair, the dragging hind legs, the cold shivering bodies to tell them their wish was coming true.

It was beastly! All of this fussing with the delicate filter experiments—and the animals munched at the greens in their cages, they hopped about, males sniffed at females and engaged in those absurd scufflings with other males which guinea-pigs and rabbits hold to be necessary to the propagation of their kind. . . . Let these giants (who fed them well) inject more of this stuff into their veins, their bellies—poison? Imagination! It made them feel happy. . . .

Roux tried again. He shot bigger doses of his filtered soup into the animals, other animals, still more animals. It was no go, there was no poison.

​That is, for a merely sensible man there would have been no poison in the filtered soup that had stood in the incubator for four days. Hadn't enough animals been wasted trying it? But Roux (let all mothers and children and the gods caring for insane searchers bless him!) was no reasonable man just then. For a moment he had caught Pasteur's madness, his strange trick of knowing what all men thought wrong to be right, his flair for good impossible experiments. "There is a poison there!" you can hear that hawk-faced consumptive Roux shout to himself, to the dusty, bottle-loaded shelves of his laboratory, to the guinea-pigs who would have snickered—if they could have—at his earnest futile efforts to murder them. "There must be a poison in this soup where the diphtheria germs have grown—else why should those rabbits have died?"

Then—I have told scientific searchers about this and they have held their noses at such an experiment—Roux nearly drowned a guinea-pig. For weeks he had been injecting more and more of his filtered soup, but now (it was like facing a night on a park bench with your last dime on the two dice) he injected thirty times as much! Not even Pasteur would have risked such an outlandish dose—thirty-five cubic centimeters Roux shot under the guinea-pig's skin and you would expect that much water would kill such a little beast. If he died it would mean nothing. . . . But into the belly of a guinea-pig and into the ear-vein of a rabbit went this ocean of filtered juice—it was as if he had put a bucketful of it into the veins of a middle-sized man.

But that was the way Roux carved his name on those tablets which men while they are on earth must never allow to crumble; for, though the rabbit and the guinea-pig stood the mere bulk of the microbe-less broth very well, and appeared perfectly chipper for a day or so afterwards, in forty-eight hours their hair was on end, their breath began to come in little hiccups. In five days they were dead, with exactly those symptoms their brothers had, after injections of the living ​diphtheria bacilli. So it was that Emile Roux discovered the diphtheria poison. . . .

By itself this weird experiment of the gigantic dose of feebly poisonous soup would only have made microbe hunters laugh. It was scandalous. "What!—if a great flask of diphtheria microbes can make so little poison that it takes a good part of a bottle of it to kill a small guinea-pig—how can a few microbes in a child's throat make enough to do that child to death? It is idiotic!"

But Roux had got his start. With this silly experiment as an uncertain flashlight, he went tripping and stumbling through the thickets, he bent his sallow bearded face (sometimes it was like the face of some unearthly bird of prey) over a precise long series of tests. Then suddenly he was out in the open. Presently, it was not more than two months later, he hit on the reason his poison had been so weak before—he simply hadn't left his germ-filled bottles in the incubator for long enough; there hadn't been time enough for them really to get down to work to make their deadly stuff. So, instead of four days, he left the microbes stewing at body temperature in their soup for forty-two days, and when he ran that brew through the filter—presto! With bright eyes he watched unbelievably tiny amounts of it do dreadful things to his animals—he couldn't seem to cut down the dose to an amount small enough to keep it from doing sad damage to his guinea-pigs. Exultant he watched feeble drops of it do away with rabbits, murder sheep, lay large dogs low. He played with this fatal fluid; he dried it; he tried to get at the chemistry of it (but failed); he got out a very concentrated essence of it though, and weighed it, and made long calculations.

One ounce of that purified stuff was enough to kill six hundred thousand guinea-pigs—or seventy-five thousand large dogs! And the bodies of those guinea-pigs who had got a six hundred thousandth of an ounce of this pure toxin—the tissues of those bodies looked like the sad tissues of a baby dead of diphtheria. . . .

​So it was Roux made Loeffler's prophecy come true; it was that way he discovered the fluid messenger of death which trickles from the insignificant bodies of diphtheria bacilli. But he stuck here; he had explained how a diphtheria germ murders babies but he had found no way to stop its maraudings. There was that letter from the mother—but Roux's researches petered out into various directions to doctors how to grow germs pure out of children's throats at the bedside, and into suggestions for useful gargles. . . . He hadn’t Pasteur's tremendous grim stick-to-itiveness, nor his resourceful brain.

But away in Berlin there toiled another Émile—the Germans leave off the last "e"—Emil August Behring. He worked in Koch's laboratory, in the dilapidated building called the "Triangel" in the Schumann street. Here great things were stirring. Koch was there, no longer plain Doctor Koch of Wollstein, but now a Herr Professor, an eminent Privy Councilor. But his hat still fitted him; he peered through his spectacles, saying little; he was enormously respected, and against his own judgment he was trying to convince himself he had discovered a cure for tuberculosis. The authorities (scientists have reason occasionally to curse all authorities no matter how benevolent) were putting pressure on him. At least so it is whispered now by veteran microbe hunters who were there and remember those brave times.

"We have showered you with medals and microscopes and guinea-pigs—take a chance now, and give us a big cure, for the glory of the Fatherland, as Pasteur has done for the glory of France!" It was ominous stuff like this Koch was always hearing. He listened at last, and who can blame him, for what man can remain at his proper business of finding out the ways of microbes with Governments bawling for a place in the sun—or with mothers calling? So Koch listened and prepared his own disaster by telling the world about his " ​Tuberculin." But at the same time he guided his youngsters in fine jobs they were doing—and among these young men was Emil August Behring. How Koch pointed the gun of his cold marvelous criticism at that poet's searchings!

And what a house of microbe hunters it was, that dingy Triangel! Its walls shook under the arguments and guttural cries and incessant experiments of Koch's young men. Paul Ehrlich was there, smoking myriads of cigars, smearing his clothes and his hands and even his face with a prismatic array of dyes, making bold experiments to find out how baby mice inherit immunity to certain vegetable poisons from their mothers. . . . Kitasato, the round-faced Japanese, was shooting lock-jaw bacilli into the tails of mice and solemnly amputating these infected tails—to see whether the creatures would perish from the poisons the microbes had made while the tails were still attached. . . . And there were many others there, some forgotten and some whose names are now famous. With a vengeance the Germans were setting out to beat the French, to bury them under a vast confusion of experiments, to save mankind first.

But particularly, Emil Behring was there. He was a little over thirty; he was an army doctor; he had a little beard, neater than Koch's scraggly one, but with less signs of originality. Just the same Behring's head, in spite of that prosaic beard, was the head of a poet; and yet, though he was fond of rhetoric, no one stuck closer to his laboratory bench than Behring. He compared the grandeur of the Master's discovery of the tubercle bacillus to the rosy tip of the snow-capped peak of his favorite mountain in Switzerland, while he probed by careful experiments into why animals are immune to microbes. He compared the stormy course of human pneumonia to the rushing of a mountain stream, while he discovered a something in the blood of rats-this stuff would kill anthrax bacilli! He had two scientific obsessions, which were also poetical: one was that blood is the most marvelous of the juices circulating in living things (what an extraordinary mysterious sap ​it was, this blood!)—the other was the strange notion (not a new one) that there must exist chemicals to wipe invading microbes out of animals and men—without hurting the men or the animals.

“I will find a chemical to cure diphtheria!” he cried, and inoculated herds of guinea-pigs with cultivations of virulent diphtheria bacilli. They got sick, and as they got sicker he shot various chemical compounds into them. He tried costly salts of gold, he tried naphthylamine, he tested more than thirty different strange or common substances. He believed innocently because these things could kill microbes in a glass tube without damaging the tube, they would also hit the diphtheria bacilli under a guinea-pig’s hide without ruining the guinea-pig. But alas, from the slaughter house of dead and dying guinea-pigs his laboratory was, you would suppose he would have seen there was little to choose between the deadly microbes and his equally murderous cures. . . . Nevertheless, being a poet, Behring did not have too great a reverence for facts; the hecatombs of corpses went on piling up, but they failed to shake his faith in some marvelous unknown remedy for diphtheria hidden somewhere among the endless rows of chemicals in existence. Then, in his enthusiastic—but random —search he came upon the tri-chloride of iodine.

Under the skins of several guinea-pigs he shot a dose of diphtheria bacilli sure to kill them. In a few hours these microbes began their work; the spot of the injection became swollen, got ominously hot, the beasts began to droop—then, six hours after the fatal dose of the bacilli, Behring shot in his iodine tri-chloride. . . . “It is no good, once more,” he muttered. The day passed with no improvement and the next morning the beasts began to go into collapses. Solemnly he put the guinea-pigs on their backs, then poked them with his finger to see if they could still scramble back on their feet. . . . “If the guinea-pig can still get up when you poke him, there may be yet a chance for him,” explained Behring to his amazed assistants. What a test that was—think of a doctor having a ​test like this to see whether or no his patient would live! And what an abominably crude test! Less and less the iodine-treated guinea-pigs moved when he poked them—there was now no longer any hope. . . .

Then one morning Behring came into his laboratory to see those guinea-pigs on their feet! Staggering about, and dreadfully scraggly looking beasts they were, but they were getting better from diphtheria, these creatures whose untreated companions had died days before. . . .

"I have cured diphtheria!" whispered Behring.

In a fever he went at trying to cure more guinea-pigs with this iodine stuff; sometimes the diphtheria bacilli killed these poor beasts; sometimes the cure killed them; once in a while one or two of them survived and crawled painfully back to their feet. There was little certainty of this horrible cure and no rime or reason. The guinea-pigs who survived, probably wished they were dead, for while the tri-chloride was curing them it was burning nasty holes in their hides too—they squeaked pitifully when they bumped these gaping sores. It was an appalling business!

Just the same, here were a few guinea-pigs, sure—except for this iodine—to have died of diphtheria; and they were alive! I often ponder how terrible was the urge forcing men like Behring to try to cure disease—they were not searchers for truth, but rabid, experimenting healers rather; ready to kill an animal or even a child maybe with one disease to cure him of another. They stopped at nothing. . . . For, with no evidence save these few dilapidated guinea-pigs, with no other proof of the virtues of this blistering iodine tri-chloride, Behring proceeded to try it on babies sick with diphtheria.

And he reported: "I have not been encouraged by certain carefully instituted tests of iodine tri-chloride on children sick with diphtheria. . . ."

But here were still some of those feeble but cured guinea-pigs, and Behring clutched at some good his murderous gropings might do. The gods were kind to him. He pondered, and ​at last he asked himself: “Will these cured animals be immune to diphtheria now?” He took these creatures and shot an enormous dose of diphtheria bacilli into them. They stood it! They never turned a hair at millions of bacilli, enough to kill a dozen ordinary animals. They were immune!

Now Behring no longer trusted chemicals (think of the beasts that had gone down to the incinerator!) but he still had his fixed notion that blood was the most marvelous of the saps coursing through living things. He worshiped blood; his imagination gave it unheard-of excellences and strange virtues. So—with more or less discomfort to his decrepit cured guinea-pigs—he sucked a little blood with a syringe out of an artery in their necks; he let the tubes holding this blood stand until clear straw-colored serum rose over the red part of the blood. With care he drew this serum off with a tiny pipet—he mixed the serum with a quantity of virulent diphtheria bacilli: “Surely there is something in the blood of these creatures to make them so immune to diphtheria,” pondered Behring; “undoubtedly there is something in this serum to kill the diphtheria microbes. . . .”

He expected to see the germs shrivel up, to watch them die, but when he looked, through his microscope, he saw dancing masses of them—they were multiplying, “exuberantly multiplying,” he wrote in his notes with regret. But blood is wonderful stuff. Some way it must be at the bottom of his guinea-pig’s immunity. “After all,” muttered Behring, “this Frenchman, Roux, has proved it isn’t the diphtheria germ but the poison it makes—it is the poison kills animals, and children. . . . Maybe these iodine-cured guinea-pigs are immune to the poison too!”

He tried it. With sundry guttural gruntings, with a certain poetic sloppiness, Behring got ready a soup which held poison but had been freed of microbes. Huge doses of this stuff he pumped from a syringe under the hides of his decreasing number of desolate cured guinea-pigs. Again, they were immune! Their sores went on healing, they grew fat. The poison ​bothered them no more than had the bacilli which made it. Here was something entirely new in microbe hunting, something Roux maybe dreamed of but couldn't make come true. Pasteur had guarded sheep against anthrax, and children from the bites of mad dogs, but here was something incredible—Behring, giving guinea-pigs diphtheria and then nearly killing them with his frightful cure, had made them proof against the microbe's murderous toxin. He had made them immune to the stuff of which one ounce was enough to kill seventy-five thousand big dogs. . . .

"Surely it is in the blood I will find this antidote which protects the creatures!" cried Behring.

He must get some of their blood. There were hardly any of the battered but diphtheria-proof guinea-pigs left now, but he must have blood! He took one of the veterans, and cut into its neck to find the artery; there was no artery left—his numerous blood lettings had obliterated it. He poked about (let us honor this animal!) and finally got a driblet of blood out of a vessel in its leg. What a nervous time it was for Behring, and I do not know whether it is Behring or his beasts who is most to be pitied, for every morning he came down to the laboratory wondering whether any of his priceless animals were left alive. . . . But he had a few drops of serum now, from a cured guinea-pig. He mixed this, in a glass tube, with a large amount of the poisonous soup in which the diphtheria microbes had grown.

Into new, non-immune guinea-pigs went this mixture—and they did not die!

"How true are the words of Goethe!" cried Behring. "Blood is an entirely wonderful sap!"

Then, with Koch the master blinking at him, and with the entire small band of maniacs in the laboratory breathless for the result, Behring made his famous critical experiment. He mixed diphtheria poison with the serum of a healthy guinea-pig who was not immune, who had never had diphtheria or ​been cured from it either, and this serum did not hinder one bit the murderous action of the poison. He shot this mixture into new guinea-pigs; in three days they grew cold; when he laid them on their backs and poked them with his finger they did not budge. In a few hours they had coughed their last sad hiccup and passed beyond. . . .

"It is only the serum of immune animals—of beasts who have had diphtheria and have been cured of it—it is only such serum kills the diphtheria poison!" cried Behring. Healer that he was, you can hear him muttering: "Now, maybe, I can make larger animals immune too, and get big batches of their poison-killing serum, then I'll try that on children with diphtheria. . . . what saves guinea-pigs should cure babies!"

By this time nothing could discourage Behring. Like some victorious general swept on by the momentum of his first bloody success, he began shooting diphtheria microbes, and iodine tri-chloride, and the poison of diphtheria microbes, into rabbits, into sheep, into dogs. He tried to turn their living bodies into factories for making the healing serum, the toxin-killing serum. "Antitoxin" he called such serum. And he succeeded, after those maimings and holocausts and mistakes, always the necessary preludes to his triumphs. In a little while he had sheep powerfully immune, and from them he got plenty of blood. "Surely the antitoxin [he hadn't the faintest notion what the chemistry of this mysterious stuff was] certainly it will prevent diphtheria," said Behring.

He injected little doses of the sheep serum into guinea-pigs; the next day he pumped virulent diphtheria bacilli into these same beasts. It was marvelous to watch them. There they were, scampering about with never a sign of sickness, while their companions (who had got no protecting dose of serum) perished miserably in a couple of days. How good it was to see them die, those unguarded beasts! For it was these creatures told him how well the serum saved the other ones. Hundreds of pretty experiments of this kind Behring made (there ​was little sloppiness now) and his helpers maybe pointed to their foreheads, asking whether their chief would ever have done saving one set of guinea-pigs and killing another set to prove he had saved the first. But Behring had reasons. "We made so many experiments because we wanted to show Herr Koch how far we had come in our immunizing of laboratory animals," he wrote in one of his early reports.

There was only one fly in the ointment of his success—the guarding action of the antitoxin serum didn't last long. For a few days after guinea-pigs had got their injections of serum they stood big doses of the poison, but presently, in a week or two weeks, it took less and less of the toxin to kill them. Behring pulled at his beard: "This isn’t practical," he muttered, "you couldn’t go around giving all the children of Germany a shot of sheep serum every few weeks!" And alas, his eagerness for something to make the authorities wide-eyed, led him away from his fine fussings with a way to prevent diphtheria—it sent him a-whoring after the pound of cure. . . .

"Iodine tri-chloride is almost as bad for guinea-pigs as the microbes are—but this antitoxin serum, it doesn’t give them sores and ulcers . . . I know it won't hurt my animals . . . I know it kills poison . . . now, if it would cure!"

Carefully he shot fatal doses of diphtheria bacilli into a lot of guinea-pigs. Next day, they were seedy. The second day their breath came anxiously. They stayed on their backs with that fatal laziness. . . . Then Behring took half of this lot of dying beasts, and into their bellies he injected a good heavy dose of the antitoxin from his immune sheep. Miracles! Nearly every one of them (but not all) began to breathe more easily in a little while. Next day, when he put them on their backs, they hopped nimbly back to their feet. They stayed there. By the fourth day they were as good as new, while their untreated companions, cold, dead, were being carried out by the animal boy. . . . The serum cured!

The old laboratory of the Triangel was in a furor now, over this triumphant finish of Behring's sloppy stumbling Odyssey ​The hopes of everybody were purple—surely now he would save children! While he was getting ready his serum for the first fateful test on some baby near to death with diphtheria, Behring sat down to write his classic report on how he could cure beasts sure to die, by shooting into them a new, an unbelievable stuff their brother beasts had made in their own bodies—at the risk of nearly dying themselves. "We have no certain recipe for making animals immune," wrote Behring; "these experiments I have recorded do not include only my successes." Surely they did not, for Behring set down the messings and the fiascoes along with the few lucky stabs that gave him his sanguinary victory. . . . How could this pottering poet have pulled off the discovery of the diphtheria antitoxin? But then, come to think of it, those first ancient nameless men who invented sails to carry swift boats across the water—they must have groped that way too. . . . How many of the crazy craft of those anonymous geniuses turned turtle? It is the way discoveries are made. . . .

Toward the end of the year 1891, babies lay dying of diphtheria in the Bergmann clinic in the Brick Street in Berlin. On the night of Christmas, a child desperately sick with diphtheria cried and kicked a little as the needle of the first syringe full of antitoxin slid under its tender skin.

The results seemed miraculous. A few children died; the little son of a famous physician of Berlin passed out mysteriously a few minutes after the serum went into him and there was a great hullabaloo about that—but presently large chemical factories in Germany took up the making of the antitoxin in herds of sheep. Within three years twenty thousand babies had been injected and like a rumor spread the news, and Biggs, the eminent American Health Officer, then in Europe, was carried away by the excitement. He cabled dramatically and authoritatively to Dr. Park in New York:

DIPHTHERIA ANTITOXIN IS A SUCCESS; BEGIN TO PRODUCE IT.

​In the excitement of this cure, those sad ones, who had lost dear ones through the first enthusiasm about the dangerous injections of the consumption cure of Koch, forgot their sorrow and forgave Koch because of his brilliant pupil Behring.

But there were still criticisms and muttered complaints, and this was natural, for the serum was no sure-fire, one hundred per cent curative stuff for babies—any more than it was for guinea-pigs. Then too, learned doctors pointed out that what happened under the hide of a guinea-pig was not the same—necessarily—as the savage thing going on in the throat of a child. Thousands of children were getting the diphtheria serum, but some children (maybe not so many as before perhaps?) kept dying horribly in spite of it. Doctors questioned. . . . Some parents had their hopes dashed. . . .

Then Émile Roux came back into the battle. He discovered brilliantly an easy way to make horses immune to the poison—they did not die, they developed no horrid abscesses, and, best of all, they furnished great gallon bottles full of the precious antitoxin—powerful stuff this serum was; little bits of it destroyed large doses of that poison fatal to so many big dogs.

Like Behring—perhaps he was even more passionately sure than Behring—Roux believed in advance this antitoxin would save suffering children from death. He thought nothing of prevention, he forgot about his gargles. He hurried to and fro between his workroom and the stables, carrying big-bellied flasks, jabbing needles into those patient horse's necks. Just then, a particularly virulent breed (so Roux thought) of diphtheria bacillus was crawling through the homes of Paris. At the Hospital for Sick Children, fifty out of every hundred children (at least the statistics said so) were being carried blue-faced to the morgue. At the Hospital Trousseau as many as sixty out of a hundred were dying (but it is not clear whether the doctors there knew all these deaths to be from diphtheria). ​On the first of February, 1894, Roux of the narrow chest and hatchet face and black skull cap, walked into the diphtheria ward of the Hospital for sick children, carrying bottles of his straw-colored, miracle-working stuff.

In his study in the Institute in the Rue Dutot with a gleam in his eye that made his dear ones forget he was marked for death, there sat a palsied man, who must know, before he died, whether one of his boys had wiped out another pestilence. Pasteur waited for news from Roux. . . . Then too, all over Paris there were fathers and mothers of stricken ones, praying for Roux to hurry—they had heard of this marvelous cure of Doctor Behring. It could almost bring babies back to life, folks said—and Roux could see these people holding out their hands to him. . . .

He got ready his syringes and bottles with the same cold steadiness the farmers had marveled at, long before, in those great days of the anthrax vaccine tests at Pouilly-le-Fort. His assistants, Martin and Chaillou, lighted the little alcohol lamp and hurried to anticipate his slightest order. Roux looked at the helpless doctors, then at the little lead-colored faces and the hands that picked and clutched at the edges of the covers, the bodies twisting to get a little breath. . . .

Roux looked at his syringes—did this serum really save life?

"Yes!" shouted Emile Roux, the human being.

"I don't know—let us make an experiment," whispered Emile Roux, the searcher for truth.

"But, to make an experiment, you will have to withhold the serum from half at least of these children—you may not do that." So said Emile Roux, the man with a heart, and all voices of all despairing parents were joined to the pleading voice of this Emile Roux.

"True, it is a terrible burden," answered the searcher that was Roux, "but just because this serum has cured rabbits, I do not know it will cure babies. . . . And I must know. I must find truth. Only by comparing the number of children ​who die, not having been given this serum, with the number who perish, having received it—only so can I ever know."

"But if you find out the serum is good, if it turns out from your experiment that the serum really cures—think of your responsibility for the death of those children, those hundreds of babies who did not get the antitoxin!"

It was a dreadful choice. There was one more argument the searcher that was Roux could have brought against the man of sentiment, for he might have asked: "If we do not find out surely, by experiment on these babies, the world may be lulled into the belief it has a perfect remedy for diphtheria—microbe hunters will stop looking for a remedy, and in the years that follow, thousands of children will die who might have been saved if hard scientific searching had gone on. . . ."

That would have been the final, the true answer of science to sentiment. But it was not made, and who after all can blame the pitying human heart of Roux for leaving the cruel road that leads to truth? The syringes were ready, the serum welled up into them as he gave a strong pull at the plungers. He began his merciful and maybe life-saving injections, and every one of the more than three hundred threatened children who came into the hospital during the next five months received good doses of the diphtheria antitoxin. Praise be, the results were a great vindication for the human Roux, for that summer, the experiment over, he told a congress of eminent medical men and savants from all parts of the world:

"The general condition of the children receiving the serum improves rapidly . . . in the wards there are to be seen hardly any more faces pale and lead-blue . . . instead, the demeanor of the children is lively and gay!"

He went on to tell the Congress of Buda-Pesth how the serum chased away the slimy gray membrane—that breeding place where the bacilli made their terrible poison—out of the babies' throats. He related how their fevers were cooled by this marvelous serum (it was like some breeze blowing from a lake of northern water across the fiery pavements of a city). ​The most dignified congress of prominent and celebrated physicians cheered. It rose to its feet. . . .

And yet and yet—twenty-six out of every hundred babies Roux had treated—died, in spite of this marvelous serum. . . .

But it was an emotional time, remember, and Roux, and the Congress of Buda-Pesth were not assembled to serve truth but to discuss and to plan and to celebrate the saving of lives. They cared little for figures then; they cared less for annoying objectors who carped about comparing figures; they were swept away by Roux's report of how the serum cooled fevered brows. Then, Roux could have answered such annoying critics (with the applause of his famous audience): "What if twenty-six out of a hundred did die—you must remember that for years before this treatment fifty out of a hundred died!"

And yet—I, who believe in this antitoxin, I say this, twenty years after—diphtheria is a disease having strange ups and downs of viciousness. In some terrible decades it kills its sixty out of a hundred; then some mysterious thing happens and the virus seems to weaken and only ten children are taken where sixty died before. So it was, in those brave days of Roux and Behring, for in a certain hospital in England, in those very days, the death rate from diphtheria had gone down from forty in a hundred to twenty-nine in a hundred—before the serum was ever used!

But the doctors at Buda-Pesth did not think of figures and they carried home the tidings of the antitoxin to all corners of the world, in a few years the antitoxin treatment of diphtheria became orthodox, and now there is not one doctor out of a thousand who will not swear that this antitoxin is a beautiful cure. Probably they are right. Indeed, there is evidence that when antitoxin is given on the first day of the disease, all but a few babies are saved-and if there is delay, many are lost. . . . Surely, any doctor should be called guilty, in the light of what is known, who did not give the antitoxin to a threatened child. I would be quick to call a doctor to give it to one of my own children. Why not, indeed? Perhaps ​the antitoxin cures. But it is not completely proved, and it is too late now to prove it one way or another to the hilt, because, since all the world believes in the antitoxin, no man can be found heartless enough or bold enough to do the experiment which science demands.

Meanwhile the searchers, believing, are busy with other things—and I can only hope, if another wave of the dreadful diphtheria of the eighties sweeps over the world again, I can only hope that Roux was right.

But even if the diphtheria antitoxin is not a sure cure, we already know that the experiments of Roux and Behring have not been in vain. It is a story still too recent, too much in the newspapers to be a part of this history—but to-day, in New York under the superb leadership of Dr. Park, and all over America, and in Germany, hundreds of thousands of babies and school-children are being ingeniously and safely turned into so many small factories for the making of antitoxin, so that they will never get diphtheria at all. Under the skins of these youngsters go wee doses of that terrible poison fatal to so many big dogs—but it is a poison fantastically changed so that it is harmless to a week-old baby!

There is every hope, if fathers and mothers can only be convinced and allow their children to undergo three small safe pricks of a syringe needle, that diphtheria will no longer be the murderer that it has been for ages.

And for this men will thank those first crude searchings of Loeffler and Roux and Behring.