On Sept 8, 1854, the Board of Governors of St James' Parish, London, removed the handle of a communal water pump on Broad Street in Soho. They acted on the advice of John Snow, a local doctor and anaesthetist, who believed that disabling the pump would end a violent cholera epidemic in the parish. Many writers have construed this event as a pivotal moment in the history of disease: proof that cholera (and, by implication, all infectious diseases) was caused by a specific contagious agent rather than by a miasma—a bad smell. In The Ghost Map Steven Johnson reminds us that the story was not so straightforward. Rather than making a material contribution to the end of the epidemic, the removal of the pump handle reflected Snow's persuasive way with the Board.
The Ghost Map fits neatly into an extremely successful genre: the “biography of a thing”. Johnson uses many perspectives—genetic, pathological, social, historical, demographic—to construct a biography of cholera, interleaved with a detailed narrative of the Soho outbreak. The eponymous map was, incidentally, drawn up by Snow to illustrate the clustering of cholera cases around the Broad Street pump. Like Peter Ackroyd and A N Wilson, Johnson is adept at evoking Victorian London, the social and sanitary implications of 2 million people living within 5 miles of London Bridge, the economy of excrement underpinning urban life. In the hands of Ackroyd or Wilson, this “biographical” approach can be breathtaking. In Johnson's hands the result is sometimes engaging, more often disappointing.
Good historians, like good anthropologists, resist the temptation to reduce their subjects to crudely drawn heroes or villains. The fact that we now accept Snow's account of contagion is perhaps the least important aspect of this complex historical narrative. But Johnson stages a Victorian melodrama in which Snow is Right and the miasmatists are Wrong—end of story. Snow is a cold, glassy, Victorian sort of hero, a Sherlock Holmes without the wit. The miasmatists, by contrast, are windy, pompous, duplicitous, “blind”. As history The Ghost Map is hopelessly one-sided, leaving the reader with little sense of the wider medical and political contexts in which Snow and the miasmatists worked. The final chapter, an essay on the future of urban life, seems to be the real subject of Johnson's interest, and it is a pity that his talents as essayist and commentator have been occupied so fruitlessly. Hindsight is always 20/20, but history need not be this myopic.