Context 159 - May 2019

22 C O N T E X T 1 5 9 : M A Y 2 0 1 9 infant diarrhoea. Crucially, however, it spreads through exposed populations in major epidem- ics of a few years’ duration, striking victims of all ages and with a high mortality rate. In 19th-century Europe it was a new and terrifying disease, unlike the endemic summer diarrhoea of infants which could be seen as a ‘normal’ hazard of childhood. The impact of cholera stimulated the develop- ment of public health. Dr John Snow (1813– 1858) pioneered the scientific investigation of disease patterns in the population, now known as epidemiology, in his meticulous investigation of cholera in London during the second and third of the listed epidemics. He was able to show repeatedly that outbreaks could be traced to sewage contamination of water supplies, whether it be a single water pump in a community (the famous Broad Street pump in Soho) or, even more tellingly, by comparison of disease rates among customers of different water companies drawing their water from heavily polluted or (relatively) clean points of the Thames. The impetus for major sanitary engineering projects was to remove the ‘miasma’ in increas- ingly populous conurbations where the streets, cesspits and local rivers had been the traditional conduits for sewage disposal. The huge pro- ject led by Joseph Bazalgette in London was prompted by the ‘Great Stink’ from the Thames in the hot summer of 1858, which caused the temporary suspension of Parliamentary busi- ness. Even when the ambitious system of sewers and pumping stations was completed in 1875, the miasmatic theory was only slowly giving way to the evidence from epidemiology and bacteriology. It was an example of the right thing being done for the wrong reason. Beginning around 1850, a system of sewers was laid with an outfall and sewage works on the River Soar north of Leicester. These works were intended to recoup their cost through a patented process to manufacture fertiliser from the efflu- ent. The design was heavily criticised from the outset and proved to be a failure. The sew- ers themselves were inadequate for the rapidly growing population and had to be supplemented by pail closets. The anticipated market for the fertiliser did not materialise. Infant mortality worsened in the town over these three decades. A memorial to Joseph Bazalgette on London’s Embankment (Photo: Prioryman, Wikimedia) CHOLERA DEATHS IN EPIDEMIC YEARS, ENGLAND ANDWALES YEARS DEATHS 1831–2 32,000 1848–9 52,000 1853–4 24,000