Ignaz Philipp Semmelweis is a Hungarian physician who is known as an "early pioneer of antiseptic procedures". He discovered a very easy solution of washing hands for preventing puerperal fever,in 1847, long before Louis Pasteur came up with his "Germ theory of disease".
Despite his publications on the study, his theory was not accepted by doctors or others in his time. It was only after his death and Louis Pasteur's theory, that his contribution to the study of health and microbiology was understood by the world.
Puerperal fever is a bacterial infection that affects women during childbirth. It is also called childbed fever. During his time, Semmelweis noticed that puerperal fever was induced in women from their obstetricians. After studying different cases, he identified the causative agent of the disease as "cadaveric particles" that were carried through the hands of the medical students and doctors who attended to childbirth after autopsy sessions.
He concluded that washing hands after sessions with an antiseptic solution of chlorinated lime solution would reduce the mortality rate due to puerperal fever to less than 1%.
Though a very significant discovery in early microbiology, before anything was known about germs and their involvement in diseases, his theory got very little popularity and much rejections atleast until his death.