12. JBS Haldane
JBS Haldane was a polymath studying the physiology of Navy divers. His father had been at the forefront of such research in the early 20th century, and Haldane hoped to follow in his footsteps but on a much more personal level. In order to study the physiological effects of various gases within the body, he repeatedly put himself in a decompression chamber, motivated for the welfare of sailors who sometimes became trapped in disabled submarines.
His work took a toll on his body, blowing out his eardrums and causing him to suffer from oxygen poisoning and crushed vertebrae. However, his research helped the science community better understand nitrogen narcosis, as well as how to calibrate gases in diving equipment for better use.