Although Galen was interested in learning through observation, he believed that some concepts were irrefutable.  

Health reforms instituted in France in the 18th Century collapsed as a consequence of

Pasteur used the same protocol he used for inoculating experimental animals with rabies vaccine on a boy who had been bitten by a rabid dog, and the boy survived

Paracelsus had an unusual medical education that allowed him to do this

A study of the use of sound waves by bats led to this discovery

This son of a famous singer used a bellows to blow air through the larynges of animals to study how pitch was achieved.

Which surgery professor, experimenting with chloroform, was found unconscious along with his entire lab staff because a container of chloroform was accidentally knocked over?

The first human kidney transplant was performed between two identical twins by

Immunosuppression was a major issue in the first kidney transplant performed by Joseph Murray on Richard Herrick

Chadwick believed that bad odors were responsible for disease in London.