"He became interested in two theories that possibly explained how cholera killed people.
The first suggested that cholera multiplied in the air. A cloud of dangerous gas floated
around until it found its victims. The second suggested that people absorbed this disease
into their bodies with their meals. From the stomach the disease quickly attacked the body
and soon the affected person died."John Snow suspected that the second theory was correct
but he needed evidence. So when another outbreak hit London in 1854, he was ready to begin
his enquiry. As the disease spread quickly through poor neighbourhoods, he began to gather
information. In two particular streets, the cholera outbreak was so severe that more than
500 people died in ten days. He was determined to find out why."