18-19TH CENTURY: CHOLERA - Britain in 1831, became an epidemic in 1832 killing over 21,0000 people that year, reappeared as epidemic in 1848, 1853-54, 1865-66, spread when infected sewage gets into drinking water, caused severe diarrhoea often killing people due to dehydration and minerals, didn't know what caused it so guess miasma