Hermann von Helmholtz (1821-1894)

Credit: Wellcome Library, London

The German scientist Hermann von Helmholtz made important discoveries in fields as diverse as physics and physiology. Applying his knowledge of physics to his medical research, Helmholtz showed that living beings obey the same physical laws as other objects. Some physiologists had believed that living bodies were special because they contained a ‘vital force’. Helmholtz disproved the existence of this force.

Helmholtz was also important for medical research because he invented many new instruments to observe and measure the body, such as the ophthalmoscope. He used these instruments to investigate how the senses work - a question that fascinated him throughout his career. His research contributed, for example, to our understanding of how we see colour, and how we hear music.