Sir Humphry Davy

Humphry Davy was born in Penzance, Cornwall, in 1778. Largely self-taught in chemistry, he made his early name at the Pneumatic Institution in Bristol investigating the physiological effects of gases, including nitrous oxide (laughing gas), whose anaesthetic potential he noted. His brilliance as a lecturer and experimenter brought him to the Royal Institution in London, where his public lectures became fashionable events.

Around 1799, while still young, Davy reportedly rubbed two pieces of ice together by clockwork in a vacuum, in surroundings kept below freezing, and observed them melt. Since no caloric fluid could have entered from the colder surroundings, he argued that the heat must have been generated by the motion itself — an early experimental blow against the caloric theory, complementing Rumford's cannon work.

Davy's greatest chemical achievements came through electrolysis. Using the powerful voltaic batteries of the Royal Institution, he isolated potassium and sodium in 1807 and calcium, strontium, barium, magnesium, and boron soon after — more elements than any other person before or since. He also showed that chlorine is an element and invented the miners' safety lamp (the Davy lamp), which saved countless lives.

He was knighted, made a baronet, and served as president of the Royal Society. Perhaps his most important act for science was hiring a young bookbinder named Michael Faraday as his assistant. Davy's health declined and he died in Geneva in 1829.