Tuhia he haere tonu mo tenei whitianga - Ko te mahi a John Snow he mea nui ki te awhina i te hononga i waenga i te mate pukupuku me te mate pukupuku me nga puna wai poke, i uru ki te matenga o te kaupapa miasma. I te pakarutanga o te mate pukupuku i te tau 1854
I te tau kotahi mano, i kitea e Snow he nui te mate i roto i nga tangata o Soho ki te papu wai i Broad Street. I whakaponohia e Snow te kāwanatanga ā-rohe ki te tango i te ringa o te papu, nā reira i tino heke iho ai ngā take o te mate korera i te rohe. I te tau 1857, i tukuna e Snow he pepa ki te British Medical Journal e kii ana he maha nga keehi o te mate pukupuku ki nga puna wai kua poke i te paru tangata. I whakamahia e Snow ngā raraunga tatauranga hei whakaatu he iti ake te tūponotanga o te mate korora ki ngā tāngata i whiwhi wai mai i ngā puna i runga ake i te awa, i te hunga i whiwhi wai mai i ngā puna i raro iho. Ahakoa i tautokona e tana rangahau tana whakaaro ko te wai poke, ehara i te hau poke te pūtake o te korera