Source: USA Today, October 16, 2006.

BOOK REVIEW

The Ghost Map The Story of London's Most Terrifying Epidemic — and How It Changed Science, Cities, and the Modern World

by Steven Johnson Riverhead Books, New York, 2006. ISBN: 1594489254.

'Ghost Map' Traces Cholera's Legacy

By Thomas Mullen, Special for USA TODAY

EDITOR'S NOTE: Thomas Mullen is the author of The Last Town on Earth.

The London cholera epidemic of 1854 may be the primary subject of Steven Johnson's thought-provoking The Ghost Map, but it's the many secondary subjects that make it such an engaging read.

Johnson builds suspense in detailing the intersecting quests of Dr. John Snow and young clergyman Henry Whitehead to find the source of the illness as it strikes the city's population.

But the most interesting passages in Ghost Map (subtitled The Story of London's Most Terrifying Epidemic — And How It Changed Science, Cities and the Modern World) come when Johnson notes how the development of cities and the merging of minds from different fields not only helped solve the cholera crisis but also shaped the world we live in today.

Ghost Map details Snow's efforts to prove his theory that cholera was a water-borne illness. Johnson, author of the provocative Everything Bad Is Good For You, which laid a defense for video games and reality TV based on cognitive science, obviously sees a soul mate in Snow, who had to fight the scientific community's belief that all disease was attributable to "miasma," or a  putrefaction of the air.

Johnson is interested not only in how groundbreaking theories are developed but also in how faulty ideas can persist. He shows how London officials were so convinced foul smells caused illness that they tried to purify the air by flushing waste out of cellars and into the Thames, which poisoned the water supply and made the cholera epidemic possible.

Ghost Map also contains surprising historical nuggets: Did you know, for instance, that because citizens who drank alcohol rather than water were less likely to fall ill, "most of the world's population today is made up of descendants of those early beer drinkers, and we have largely  inherited their tolerance for alcohol"?

Johnson notes that cities in the 1800s made epidemic disease likely, thanks to overcrowding and inefficient waste disposal. But he also argues that only in urban environments would people from such disparate backgrounds as Snow and Whitehead be able to share their expertise to solve seemingly intractable problems.

In Victorian London, cities were vilified as physical and moral cesspits. Johnson argues that, though still occasionally criticized as hotbeds of pollution and social ills, cities are in fact humankind's best strategy for survival in an age of finite energy sources and information-driven economies. If life in the big city (Johnson lives in Brooklyn) led to the creation of Ghost Map,  then that's strong evidence, indeed.

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