Like other branches of knowledge, it has proliferated into a host of jargon-filled specialisms. One of the aims of the new book is to undo the damage, producing (apart from the decidedly institutional price tag) an account comprehensible to lay intruders.
Half the 1,100 pages are devoted to essays on general topics, and half to the histories of individual diseases and conditions, from Aids to yellow fever. Some of the 158 varieties of affliction are apocalyptic, such as the Black Death, which wiped out almost half Europe's population; some quirky, such as pica, which sounds like an occupational disease of typography, but is, in fact, the compulsion to eat earth.
Dipping into the cornucopia of miseries, we learn that those with the characteristic piebald appearance caused by vitiligo have traditionally been either reviled or given privileged status, including the honour of bearing Montezuma's litter. Michael
Jackson, said to be suffering from the condition, seems to be a case in both points. But few diseases do much for human dignity. The fearsome-sounding dracunculiasis, for instance, is still treated by the traditional method of wrapping the worm that
causes it around a stick as it emerges. It is one of those conditions confined in the West to textbooks, obscure to all but the infected, whose ranks swell by as many as 15 million a year.
The sick, even more than the poor, are always with us. In fact, we are the sick, too; it's just that we are commonly laid low once past 50, whereas the poor of the earth are lucky to reach that age. The Cambridge History has been compiled with an eye to posterity, and future historians ought to be impressed by its sobriety. Even in a rare story with a triumphant ending, such as the eradication of smallpox, the element of luck in the development of the vaccine is stressed.
The one major advance has been the quelling of the great epidemics - except for those caused by viruses, such as the influenza pandemic of 1918-19, which killed over 20 million; or Aids. Ominously, HIV is not the only newcomer to the catalogue. The editor uses the examples of Ebola, Marburg and Lassa, all new viruses, to suggest a sinister counterpart to the green campaigners' image of the rainforests as uninventoried pharmacopoeias full of cures for cancer and other sicknesses. He speculates that they could also be a Pandora's box whose opening will unleash a swarm of new pathogens upon the world.
Whatever the future may hold, medical historians have little cause for triumphalism. As Stephen R Ell observes, in his essay on the history of disease in Europe, medicine hardly comes into the story. Nor does he associate health with human happiness. The ancient Greeks were not much troubled by disease, he infers, because they abandoned their infants to die; nor were the great societies of the early Roman period - their armies could mount sustained campaigns without succumbing to epidemics.
Even the concept of disease, a human phenomenon infinitely more complex than its biology, overwhelms attempts to master it. There seem to be diseases of the Zeitgeist, limited to a particular time and culture. In 18th-century England, the better classes suffered from 'hypochondriack' disorders; in the 19th century, they were replaced by neurasthenics. But whatever afflictions disappear over the next century, and whatever new ones arise, the lesson of this edition is that disease dwarfs medicine, and probably always will.