The author reviews the spread of cholera and compiles clinical and epidemiological evidence to explain its transmission. He presents case studies documenting person-to-person spread and argues against airborne effluvia, using pathological and fluid analyses to show the morbid agent enters the alimentary canal. Multiple outbreak investigations link localized epidemics to polluted water sources, supported by maps, tables, and comparative mortality data across different water supplies, institutions, and neighborhoods. The work assesses environmental and infrastructural factors such as water-company networks, river contamination, elevation, and dry weather that alter exposure risk.