biology scientists

theodor schwann

if animals are made of cells, then they have a nucleus

edward jenner

if cowpox grants an immunity to smallpox then if exposed to cowpox won't be infected with smallpox

ignatz semmelweis

if fever was something that could be transferred from person to person, doctors must wash their hands between patients.

Francesco Redi

if maggots were spontaneously being produced from meat then meat in a covered jar would get maggots

robert koch

if microbes were responsible for anthrax then bad air doesn't cause it

alexander fleming

if mold contains a substance that kills bacteria, then when added to colonies of bacteria they will die

louis pasteur

if particles in the air could cause food to spoil, then food should be covered

john snow

if water was the cause of sickness then cholera would be centered around water sources