In the Hunterian Museum at the Royal College of Surgeons of England is a silver nose, painted pink, affixed to a pair of wire earpieces. The nose was fashioned for a woman who had lost her own to syphilis. When she married a man who liked her better without a nose, she gave the prosthetic away, and it ended up in the collection of the experimental surgeon John Hunter. This is the same Hunter who injected himself with pus drawn from a gonorrhea-infected prostitute on the assumption that she couldn't possibly have syphilis as well, since in his view, it was a different stage of the same disease. He was wrong, and died of it—deceived by one of the many masks/aliases/false noses of the Pox.

Syphilis is a trickster. In 1879, Jonathan Hutchinson, the first researcher to catalogue its many guises, dubbed it "The Great Imitator" for its ability to mimic other diseases. The initial outbreak might feature the unmistakable lesions exuberantly described by Théophile Gautier: "Boils are exploding in groins like shells, and purulent jets of clap vie with the fountains in the Piazza Navona." It also might not. After that the illness seemed to go away of its own accord, except that as the years went by, the infected fell victim to a battery of afflictions. Blindness, heart disease, stomach cramps, depression, headaches: Only a doctor possessed of a very long view could see a pattern in these seemingly unrelated disorders. You might almost say that the lack of a pattern was the pattern.

The Great Imitator was also the great secret, for reasons ranging from pudency to the security of nations. Doctors' files were burned. Genteel biographers left their suspicions unvoiced. Letters to friends were circumspect; one does not brag about a case of syphilis—unless one is Guy de Maupassant, crowing in a transport of schadenfreude:

I've got the pox! at last! the real thing! not the contemptible clap . . . no—no, the great pox, the one which Francis I died of. . . . Allelujah, I've got the pox, so I don't have to worry about catching it any more, and I screw the street whores and trollops, and afterward I say to them "I've got the pox." They are afraid, and I just laugh.

With less forthcoming subjects, scholars must become detectives, listening for the thing not said. The history of syphilis is told largely by omission. In Pox, Deborah Hayden attempts to put words to the unmentionable, pursuing a disease whose most recognizable attribute is that it cannot be recognized. Maybe it's not surprising that she does not entirely succeed.

Pox is most interesting when tracing the early history of the disease: Did the New World give Columbus, who imported so many new ways to die, a poisonous thank-you gift? The Pox that devastated Naples broke out just two years after Columbus's return. In ten years it had conquered Europe; in seventeen it had reached Japan. Cures included perching over a pot of hot mercury inside a one-man tepee and wrapping the afflicted organ in spiderwebs. Hayden has a plodding style prone to repetition (the occupation of Naples is narrated several times over), but she has rounded up some choice tidbits for readers with a taste for malpractice: the injection of a group of young prostitutes with infected pus, a chimpanzee's infected clitoris "proudly displayed to enthusiastic onlookers," chocolates laced with mercury so men could treat their wives without their knowledge.

A peculiar feature of Pox is its preface, a lyrical evocation of syphilitic delirium ("electricity lights my brain, i am the lightning rod of god, i am a zigzag doodle drawn by god's hand"). In Hayden's fantasy, syphilis is painful but revelatory, and not without a noxious seductiveness. Maybe the disease has its compensations. One symptom of late-stage syphilis is megalomania. In the right person, might delusions of grandeur become, well, just grandeur? If so, Hayden only hints as much, shy about giving syphilis too much credit (Beethoven) or blame (Hitler). Some of her subjects are bolder. Nietzsche declares, "In the midst of torments . . . I . . . thought things through for which I am not enough of an acrobat, not cunning and not cool enough under healthier conditions." That Hayden does not go so far is to her credit as a scholar, but deprived of this polemic, the book lacks direction. Exceptional lives lose their individual character in lists of afflictions: abdominal cramps, facial neuralgia, blindness, headaches, vomiting. After all, Beethoven's stomach cramps are not that different from Joyce's, yours, or mine. The cautious conclusion of each story begins to seem laughably foregone as, with a fanfare stuck on repeat, Hayden pulls a spyrochete out of every notable's hat. Biographers may bridle at the damage to the reputations of their pet subjects. Others will wonder why they should care.

There is an answer, I think. History does not make much room for the body, and yet there is no history without it. It is tonic to consider the bodies of influential people, to remember that we are not summed up by our biographies. Something escapes transcription. That something is the essential mystery—that out of a mash of cinders and saltwater comes the capacity to love an idea, hum a tune, tell a lie. The diseased body stages a revolt against those functions that biographers record, reasserting the animal in pain, so similar in the end to other animals in pain. What makes these stories redundant, handled differently might make them resonate with one another and with our own lives: that we all have at least one thing in common—a vulnerable body.

Shelley Jackson is the author of The Melancholy of Anatomy (Anchor, 2002).