English natural philosopher · 1731–1810
Henry Cavendish
Henry Cavendish was the first to recognise hydrogen as a distinct substance. A wealthy recluse who barely spoke to anyone, he also showed that water is a compound and measured the density of the Earth.
How Hydrogen was found
In 1766 Cavendish dropped metals such as zinc, iron and tin into acids and collected the gas that bubbled off. He showed it was the same gas whatever metal he used, that it was far lighter than air, and that it burned. He called it “inflammable air”.
In 1781 he exploded inflammable air with ordinary air and found that the only product was water. Lavoisier repeated the experiment, concluded that water is made of two elements, and named the gas hydrogen, “water-former”.
Life and career
Born 1731 · Died 1810
Cavendish was born in Nice to an aristocratic English family and studied at Cambridge, leaving without a degree. He inherited a fortune and spent it on books and instruments, working alone in his London house.
He was so shy that he communicated with his servants by note. In 1797–98 he used a torsion balance to measure the gravitational pull between lead spheres, which gave the density, and so the mass, of the Earth. Many of his findings on electricity were only published a century after his death, by James Clerk Maxwell.
Also known for
- The Cavendish experiment, which weighed the Earth
- Showed that water is a compound
Legacy
The Cavendish Laboratory at Cambridge, where the electron was discovered and DNA’s structure worked out, is named after his family.
Discovered in the same era
Other elements identified within ten years of 1766.