John Frederic Daniell (12.03.1790—13.03.1845) was an English scientist and inventor, a Fellow of the Royal Society (1813) and its secretary in 1839—45. He was born in London. He was a director of the Continental Gas Company and in 1831—45 professor at the University of London.
His research concerned electrochemistry, electricity, molecular physics and meteorology. He invented the hygrometer (1818), described a new pyrometer and constructed a water barometer (1830). He invented (1836) a chemical cell of copper and zinc (the Daniell cell), the first source of a steady direct current. He observed (1836) that the layer of copper deposited on the electrode in his cell reproduces the features of the surface of that electrode. He tried to explain the main atmospheric phenomena. He was a populariser of science.
The Rumford Medal (1832) and the Copley Medal (1837).