He was influenced by Snow 's idea that cholera spreads by consumption of water contaminated by human waste .
A former believer in the miasma theory of disease , Whitehead worked to disprove false theories .
Whitehead was influenced by Snow 's idea that cholera spreads by consumption of water contaminated by human waste .
A former believer in the miasma theory of disease , Whitehead worked to disprove false theories .