Free The Great Influenza by John M Barry

up for it, attracted as Welch had been to this new science, to the microscope, to experimentation. And Welch did not simply teach; he inspired. His comments always seemed so solid, well grounded, well reasoned. A colleague observed, 'He would leak knowledge.' And the excitement! Each time a student fixed a specimen on a slide and looked through a microscope, an entire universe opened to him! To some, discovering that universe, entering into it, beginning to manipulate it, was akin to creating it; they must have felt almost godlike.
    The College of Physicians and Surgeons had to offer a laboratory course to compete. It beseeched Welch to teach it. He declined out of loyalty to Bellevue but recommended the hiring of T. Mitchell Prudden, an American he had known (and considered a rival for the Hopkins job) in Europe. It was the first of what would be uncounted job offers that he engineered. Meanwhile one of his students recalled 'his serious, eager look, his smiling face, his interest in young men which bound them to him. He was always ready to drop any work in which he was engaged and answer even trivial questions on any subject - in fact he was never without an answer for his knowledge was encyclopedic. I felt instinctively that he was wasted at Bellevue, and was destined to have a larger circle of hearers.'
    But despite the throngs of motivated students taking the two courses, neither Prudden nor Welch prospered. Two years went by, then three, then four. To cobble together a living, Welch did autopsies at a state hospital, served as an assistant to a prominent physician, and tutored medical students before their final exams. As he passed his thirtieth birthday he was doing no real science. He was making a reputation and it was clear if he chose to concentrate on practice he could become wealthy. Little medical research was being done in America (although the little that was done was significant) but even that little he had no part of. In Europe science was marching from advance to advance, breakthrough to breakthrough. The most important of these was the germ theory of disease.
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    Proving and elaborating upon the germ theory would ultimately open the way to confronting all infectious disease. It would also create the conceptual framework and technical tools that Welch and others later used to fight influenza.
    Simply put, the germ theory said that minute living organisms invaded the body, multiplied, and caused disease, and that a specific germ caused a specific disease.
    There was need for a new theory of disease. As the nineteenth century progressed, as autopsy findings were correlated with symptoms reported during life, as organs from animals and cadavers were put under a microscope, as normal organs were compared to diseased ones, as diseases became more defined, localized, and specific, scientists finally discarded the ideas of systemic illness and the humours of Hippocrates and Galen and began looking for better explanations.
    Three theories stood as rivals to the germ theory.
    The first involved 'miasma.' Several variations of this concept existed, but they basically argued that many diseases were caused by some kind of putrefaction in the atmosphere, or by some climactic influence, or by noxious fumes from decaying organic materials. In China the wind was originally regarded as a demon that caused illness. Miasmas seemed a particularly good explanation of epidemics, and the unhealthiness of swamp regions seemed to support the theory. In 1885, when Welch considered the germ theory as proven, the New York City Board of Health warned that 'laying of all telegraph wires under ground in one season' would prove highly detrimental to the health of the city' through the exposure to the atmosphere of so much subsoil, saturated, as most of it is, with noxious gases'. Harlem Flats [had] a sufficient supply of rotting filth to generate fetid gases adequate to the poisoning of half the population.' As late as the 1930s one