But it was to take the country’s regular physicians more than fifty years to recover completely from the drubbing Thomson had given them. Millions of Americans went on dosing themselves with herbal remedies and consulting herbal practitioners. Some of these practitioners had picked up their trade on their own, but many were graduates of one of the twenty-odd schools of botanic medicine that were founded in the United States in the nineteenth century. In 1901 a medical historian named Alexander Wilder estimated that several thousand botanic, reformed, physiopathic, and physio-medical doctors were still practicing in the United States. Most of them, according to Wilder, were treating patients pretty much along the lines laid down by Samuel Thomson nearly eighty years before.

Thomson’s ideas also unquestionably influenced the founders of the eclectic school of medicine, which flourished in the middle and late years of the century. Most eclectics were graduates of orthodox medical schools, and while they did on occasion prescribe “mineral” medicines, they stuck mainly to vegetable remedies, and eschewed both calomel and the lancet. The first eclectics often went in for heroic botanic medicine, attempting to blast out disease with potent vegetable cathartics. Alexander Wilder, who was himself an eclectic physician, conceded that in the early years of the movement the medicines prescribed by eclectics were “often distasteful and repulsive beyond the power of sensitive patients to endure.” But as time went by the eclectics came to rely on inoffensive drugs, and to prescribe them in small quantities, on the sensible theory that often the best thing to do for a sick person was to help him to rest comfortably and, as a leading eclectic physician put it, to keep “the bowels in such restful condition that they would not disturb the patient.”

After 1900, herbal medicines lost much of their appeal. Although able to hold their own in competition with calomel, they were completely outclassed by new and rational forms of therapy based on recent discoveries about human physiology and the nature of disease. As L. J. Henderson, a widely respected physiologist and medical sociologist, pointed out some forty years ago, doctors could at long last actually cure people, at least some of the time. “I think it was about 1910 or 1912,” Henderson observed, “when it became possible to say of the United States that a random patient with a random disease consulting a doctor chosen at random stood better than a fifty-fifty chance of benefiting from the encounter.”

But while most botanic doctors were put out of business by the coming of scientific medicine, the voice of Thomson and his disciples can still be heard, at least faintly, in the land. The notion that simple herbal remedies are inherently superior to the dangerous chemicals prescribed by doctors continues to be given currency by books such as Back to Eden , a work described by its publisher as a “million-copy best seller” that came out in 1939 and is still selling briskly in health-food stores. Its subtitle is “The Classic Guide to Herbal Medicine, Natural Foods, and Home Remedies,” and its author, Jethro Kloss, devotes a good deal of space to lobelia. Describing Thomson’s favorite remedy as “a most efficient relaxant, influencing mucous, serous, nervous, and muscular structures,” Kloss recommends its use for the treatment of “coughs, bronchitis, asthma, whooping cough, pneumonia, hysteria, convulsions, suspended animation, tetanus, febrile troubles, etc.”

“Lobelia possesses most wonderful properties,” Kloss goes on to say. “It is a perfectly harmless relaxant. It loosens disease and opens the way for its elimination from the body. Its action is quick and more effective than radium.” Nonpoisonous herbs like lobelia, Kloss concludes, will do everything that conventional doctors try to do with “mercury, antitoxin, serums, vaccines, insulin, strychnine, digitalis, and all [their] poisonous drug preparations. …” Samuel Thomson could not have put it better himself.

… But the patient died