by Thomas Goetz
Pasteur deserves criticism not only for his defective methods, but also for the way in which he has publicized his investigations. In industry it may be permissible or even necessary to keep secret the procedures that lead to a discovery. However, in science different customs prevail. Anyone who expects to be accepted in the scientific community must publish his methods, so that everyone is able to test the accuracy of his claims. Pasteur has not met this obligation. . . .
Thus, Pasteur follows the tactic of communicating only favorable aspects of his experiments, and of ignoring even decisive unfavorable results. Such behavior may be appropriate for commercial advertising, but in science it must be totally rejected. At the beginning of his Geneva lecture, Pasteur placed the words “Nous avons tous une passion supérieure, la passion de vérité.” [We all have a greater passion, a passion for truth.] Pasteur’s tactics cannot be reconciled with these words. His behavior is simply inexplicable.
On and on it goes like this, for page after page. Koch interspersed his derisive volleys with dismissive critiques of Pasteur’s methods. Repeatedly, Koch claims to be championing proper scientific procedures, and every time, he places Pasteur as being outside this method. He even tossed in what he regarded as the worst insult of all: “Pasteur is not a physician.” By this time, the entire European community of medical scientists was reading, agog, the testy battle between these two titans of science. And it was only going to get worse.
Pasteur composed his response, an open letter, published in the Revue scientifique on Christmas Day 1882, a fact that shows how deeply the attacks affected the French scientist. This time, Pasteur uncorked his sense of outrage and let it spew. “You ascribe to me errors that I have not committed,” he cried; “you denounce them and make a lot of noise with your triumph. . . . You are wrong, sir, you are setting yourself up for another foiled expectation in which you will be forced to change your opinion.” And so the Frenchman railed on against the German, giving as well as he got.
The feud between Pasteur and Koch is one of the great battles of science, in part because they were so foolishly public with it. But behind the quarrels over the science itself, there have been few explanations for the rancor and its pointedly personal nature. Many historians, understandably, have attributed the whole thing to French-German antagonism, citing Pasteur’s remarks in letters and Koch’s appeals for German diligence. Undoubtedly, the two were both patriots and relished the chance to take on a fight with national significance. There’s reason to believe part of the initial antagonism was sparked through simple miscommunication. In his remarks in Geneva, Pasteur evidently referred to Koch’s published work as “recueil allemand,” meaning “collection of German works.” But Koch’s translator in the front row heard this as “orgueil allemand”—“German arrogance.” Hearing this mistranslation, Koch felt personally insulted and reacted in kind. (Ironically, his reaction was a perfect display of what may be described as German arrogance.) Pasteur, of course, had no way of knowing that his words had been erroneously transformed into an insult, so he was rightly shocked when what he considered a scientific debate turned personally ugly.
But patriotism was only part of what was going on. Reading the petulant dialogue closely, one sees that, at root, theirs was a debate over an issue that has long turned respected scientists into petulant sticklers: the matter of credit and recognition for one’s work. Pasteur and Koch were each aggrieved that the other had denied him the equivalent of a citation—a footnote or a reference or some indication that the one recognized the other’s work.
In the middle of Koch’s critique, he includes this:
Pasteur believes that he has discovered the etiology of anthrax. This etiology could only be established by identifying the enduring forms of anthrax bacilli, the conditions of their origin, their characteristics, and their relation to soil and water. Although I have no interest in priority disputes, these matters are so obvious that I cannot ignore them. I can only answer Pasteur’s claims by referring to my publication of 1876 that describes the generation of anthrax spores and their relation to the etiology of anthrax. Pasteur’s first work on anthrax was published one year later, in 1877. This requires no further comment.
Reading this, Pasteur obviously spotted a sore spot for Koch, and he picked at the scab accordingly. First, Pasteur pointed out that he had, in fact, been among the first scientists outside Germany to give Koch a public nod—which he had, not in the 1877 original paper, but in a speech that same year before the Academy of Sciences in Paris, where he described Koch’s anthrax paper as “a remarkable memoir.”
But then Pasteur throws the same offense back at Koch, noting that Koch’s etiology of anthrax bore a great debt to Pasteur’s own work with silkworms.
Why did you hide all of this to the readers of your first memoir? Are you going to say that you have ignored the existence of my work on the diseases of the silk worm, which was published in 1869–70? Your assertion would be insignificant because, in matters of science, no one is permitted to ignore a discovery, and moreover, how many opportunities did you not have, since 1877, to come back on these facts! . . . In one word, sir, it is not you who has made the discovery of the mode of generation of the bacilli, and the vibrio spoors; it is not you who has brought attention to their curious mode of formation; it is not you who has recognized their preservation in dust form and the long duration of their vitality. The precision with which I have described the formation of these ganglia, corpuscular-germs, and spoors, is such that you could have resorted simply to making a copy of the figure which illustrates this on page 228 of my work in order to introduce it in your memoir of 1876, and make use of it to illustrate what you have said about the bacillus anthracis.
Their mutual spite, it turns out, was based on their mutual impression that their landmark work had been not just slighted, but also deliberately ignored. Each felt that his greatest rival had not had the respect to give him his proper due. To men such as Koch and Pasteur, who were so aware of the portentous nature of their discoveries, this wasn’t just an insult; it was an attempt to write the other out of history. They may have been enlisted in a common fight for the germ theory, and against all that passed as science before the germ theory, but that larger fellowship was overshadowed by pique. Without the public recognition of one for the other, there was no room for magnanimity; each could only take umbrage at the insult.
If there’s a silver lining here, it’s that each plainly cared about the opinion of the other—and was hurt when his rival didn’t note how his work was drawing on the other’s. It’s unfortunate as well because both were in favor of standards for science, and it was both of them, together, who were advancing the cause of science. Building on each other’s work, building on each other’s discoveries, pushing for the reproducibility of the results—this is how science is supposed to happen. Even their argument itself, as public and hostile as it was, demonstrated that science was shifting toward clearer standards and protocols. Their mistake was to make that process so personal and for each to search so vigorously for the other’s failures rather than recognize his merits. The sight of these two great visionaries sullying themselves may have made for great theater, but it was surely embarrassing to two men who, otherwise, stood as champions of reason over emotion.
So who was right? From our vantage point today, we can see that while Koch may have been right about a detail or two in Pasteur’s process, he was altogether wrong to castigate Pasteur’s work as a whole. Koch may have resented Pasteur’s theatrical methods or his experimental élan, but Pasteur’s instincts had rightly guided him to a valid conclusion about the role of earthworms and about the viability of the vaccine. The keen powers of observation that had served Koch so well previously—as when he assessed wound infections in Wöllstein or when he recognized that a simple potato could be a transformative medium for cultures—had failed him this time. The cool demeanor that had allowed his every success had been, at least
in this exchange, abandoned. In its place were pique and anger and unseemly ruthlessness. Koch was too quick to light wildfires where candles would have been more appropriate—and it wouldn’t be the last time.
• • •
BACK IN BERLIN, THE ROUTINE WORK IN KOCH’S NEW LAB WAS thankfully far removed from the drama of open letters and public denunciations. In this small warren of rooms, with the stench of caged animals and the acrid pinch of chemicals filling the air, the day-to-day lab work would have been nearly overwhelming, leavened only by the discoveries that the work so steadily yielded.
For Koch in particular, the daily work was all-consuming. Gaffky and Loeffler, two lab assistants he’d been assigned when he arrived in 1880, were soon joined by two more assistants, and then still others. Koch’s work started to gain official attention, and accordingly, his resources grew. This was surely a mixed blessing, not just because of the effort it took to manage a growing laboratory. He was completely untrained for such a role and, apart from his days in university at Göttingen, hadn’t spent much time even with other scientists. In the space of a few months, he went from being a solo scientist, with his own procedures and habits, to working in a busy laboratory filled with assistants. Koch had to determine quickly not only how to perform science in this new milieu, but also how to lead others, teach them his methods, and externalize what had been, for years, a strictly internal process.
To his credit, he seemed to handle it. Within the first year in Berlin, his staff published a half dozen breakthrough papers on their bacteriological discoveries. Koch himself published at least three major papers, including one on plating techniques and cultures, another on disinfection. The disinfection paper was notable because it was one of the first rigorous analyses of Lister’s carbolic acid and how it worked. Koch found that, in fact, carbolic acid didn’t kill all microbes, leaving some room for improvement. So Koch explored different combinations of boric acid, hydrochloric acid, sulfuric acid, quinine, iodine, chlorine, calcium, and even salt, all in different concentrations and several combinations. Eventually he settled on mercuric chloride, a powerful acid that had been avoided as a disinfectant because it was considered an outright poison. But his experiments showed that, when significantly diluted, with up to five thousand parts water, it killed microbes quickly and could then be safely rinsed away with water. Rather than take Koch’s work as an affront, Lister was entirely grateful, and he soon altered his own methods accordingly.
Koch and his colleagues continued to push for disinfection, moving on from antisepsis (disinfecting a wound directly) to asepsis (sterilizing the surgical environment of implements and the operating environment). Soon, Koch’s team had devised a process for steam sterilization that, even at short durations, completely killed any present bacteria. (As with other of Koch’s breakthroughs, these procedures continue to be practiced today.)
In Paris, meanwhile, Pasteur kept pace. In 1880 he proved definitively that bacteria caused septicemia in the blood. In 1881, Koch published his new plating techniques, followed by Pasteur’s work on infectious pleuropneumonia in cows and erysipelas in swine. In 1883, Koch’s assistant Friedrich Loeffler identified the causal agent of diphtheria. And in 1885, Pasteur developed an effective vaccine for rabies. It was a remarkable time to be a bacteriologist, an era of apparently endless opportunity for discovery.
Though competition was an essential component of the Koch and Pasteur rivalry, internally each team thrived because of the closeness of the group. For his part, Pasteur recruited largely veterinarians and chemists, a preference that reflected his nonmedical background, while Koch recruited biologists and physicians for his lab. This gave each team a shared philosophy and likewise guided them in certain directions. Koch’s group, steeped in Wissenschaft, excelled at the minutiae of the microscope, the exacting process of identification and confirmation. Pasteur’s team was more focused on applications than technique. (Pasteur famously said that all science is applied science, a sentiment that would have been intuitive among his group but that would have seemed beside the point for Koch’s team.) This steered the French team toward work that, in 1885, led to the vaccination for rabies, even though it would be decades before the causative agent (a virus, not a bacterium) was identified.
As the competition between Paris and Berlin increased, the cooperation within the two teams must have been a steadying force, driving the team members to work harder and harder, sacrificing nights and families in order to push themselves to a new discovery. Pasteur and Koch’s would be one of the great rivalries of science—and without the rivalry, there would have been far less science. The two men may have been from competing schools and may have had different dogmas, but they were fellow revolutionaries. Their every discovery made it more difficult for other scientists to continue doubting the germ theory.
Of course, as with any revolution, there would be holdouts and counterrevolutionaries. Into the 1880s and ’90s, plenty of noteworthy scientists denounced Koch and Pasteur equally as mischief-makers. As late as 1883, Michel Peter, a Parisian physician held in high esteem by his colleagues, went so far as to denounce Pasteur’s work to his face, at an address at the National Academy of Medicine. “What do I care about your microbes? . . . I have said, and I repeat, that all this research on microbes are not worth the time spent on them or the fuss made about them, and that after all the work nothing would be changed in medicine, there would only be a few extra microbes. Medicine . . . is threatened by the invasion of incompetent, and rash persons given to dreaming.”
But as the discoveries mounted, these holdouts were increasingly marginalized. Every discovery chipped away at the skepticism—and created new expectations for science. Increasingly, there was a reason to believe that science and medicine could explain things, that they could create solutions to the ailments of humanity. Pasteur himself boldly claimed, “It is within the power of man to eradicate infection from the earth.”
This, more than the individual discoveries of any one bacterium, was the real revolution. Bacteriology was, in today’s parlance, a plat-form for innovation, one that could apparently be used for various challenges and, with enough work and discipline, produce a result.
As the race between Koch and Pasteur took on greater stakes, Koch realized the rhetoric wasn’t getting him anywhere; in fact, it was distracting him from the laboratory. What he needed was a new breakthrough. It wasn’t enough to develop procedural innovations and mechanical improvements; it wasn’t enough to publish significant but incremental discoveries. He needed something dramatic. He needed a discovery that could establish, definitively, his leadership in science—and, along the way, his primacy over Pasteur. He needed to move beyond the small stakes of a disease such as anthrax, which had a great economic cost in lost livestock but a human death toll of a few hundred annually, to one that deeply affected humanity, with a death toll in the millions.
What he needed, he realized, was a disease so ubiquitous, so pervasive, and so deadly that it was almost invisible.
CHAPTER 4
1882 • The Breakthrough
“The Etiology of Tuberculosis,” Robert Koch’s paper, published in 1882
On the brisk evening of March 24, 1882, Robert Koch left his rooms at the Imperial Health Office, walked across the Spree River, and headed toward the University of Berlin’s Physiology Institute, a hulking caramel brick building a few blocks to the south. He was carrying boxes of equipment and specimens, but he couldn’t tote the load by himself; his assistant Friedrich Loeffler shared the burden. As they walked, Koch volunteered that he was nervous. He was about to demonstrate an important discovery, a finding so startling that he scarcely expected anybody to believe him. At the least, he told Loeffler, he anticipated all sorts of quarreling to follow, “a year of hard battle.”
Arriving at the institute, Koch and Loeffler climbed a few stairs to the library, where the demonstration would take place. The room was lined floor to ceiling with
glass-doored bookshelves, each stocked with scientific journals, decades of estimable research that Koch was about to make obsolete, all at once. In the front of the room, Koch began laying his equipment out upon a large wooden table, an array of microscopes, test tubes, flasks, and tissue specimens taken from a variety of animals. Finally, he laid out dozens of small glass plates smeared with a white gelatin film, each containing a bacteria culture.
In the middle of the room, a large conference table held a dozen or so chairs, but as the room filled up, the table was moved to the side, until finally there were more than a hundred men standing elbow to elbow. The most eminent scientists in Germany were there. Some were admirers of Koch, who after less than two years in Berlin had established himself as a man to be watched. Paul Ehrlich was among these. Years earlier, he had witnessed Koch’s anthrax demonstrations in Breslau, and he was now a junior member of Koch’s team. Soon he would go on to develop the field of immunology; in 1908 he would win the Nobel Prize in medicine.
Others were skeptics; for them, Koch’s germ theory was far from settled science. Chief among these was Rudolf Virchow, Berlin’s “professor of professors,” who stood, quiet and stern, among the others in the room. Years earlier, Koch had admired Virchow, even taking a special trip to Berlin during medical school to hear him lecture on physiology. But as a professional, Virchow had given Koch nothing but grief. As Koch’s work grew more influential and as his stature in Berlin grew, Virchow had publicly scorned both, deeming the germ theory inessential for medicine. It was a mean insult, one that Koch couldn’t help but take personally.