that miasma arose from the soil surrounding the River Thames. It contained decaying organic matter which contained miasmatic particles and was released into the London air. Miasma theorists believed in "cleansing and scouring, rather than through the purer scientific approach of microbiology". Farr later agreed with Snow's germ theory following Snow's publications. Germ theory In contrast, the germ theory held that the principal cause of cholera was a germ cell that had not yet been identified. Snow theorised that this unknown germ was transmitted from person to person by individuals ingesting water. John Simon, a pathologist and the lead medical officer for London, labelled Snow's germ theory as "peculiar". Excerpt from John Simon: This doctrine is, that cholera propagates itself by a 'morbid matter' which, passing from one patient in his evacuations, is accidentally swallowed by other persons as a pollution of food or water; that an increase of the swallowed germ of the disease takes place in the interior of the stomach and bowels, giving rise to the essential actions of cholera, as at first a local derangement; and that 'the morbid matter of cholera having the property of reproducing its own kind must necessarily have some sort of structure, most likely that of a cell. Even though Simon understood Snow's theory, he questioned its relation to the cause of cholera. Investigation by John Snow The Broad Street outbreak was an effect rather than a cause of the epidemic. Snow's conclusions were not predominantly based on the Broad Street outbreak, as he noted that he hesitated to come to a conclusion based on a population that had predominantly fled the neighbourhood and redistributed itself. He feared throwing off results of the study. From a mathematics perspective, John Snow's innovation was focusing on death rates in areas served by two water companies which drew water from the River Thames, rather than basing it on data from victims of the Broad Street pump (which drew water from a well). Snow's work also led to a far greater health and safety impact than the removal of the Broad Street pump handle. Deactivating the pump "hardly made a dent in the citywide cholera epidemic, which went on to claim nearly 3,000 lives". Snow was sceptical of the prevailing miasma theory, which held that diseases such as cholera or the Black Death were caused by pollution or a noxious form of "bad air". The