Henry Cavendish (10.10.1731-24.02.1810) was an English physicist and chemist and a Fellow
of the Royal Society (1760). He was born in Nice (France). In 1749 — 53 he studied at the University of Cambridge. He spent most of his life in solitude, giving himself up entirely to scientific work.
He carried out his research in his own laboratory. He published only those papers of his whose reliability he was completely sure of. Because of this his work on electricity long remained unknown. Published in 1879 by J. Maxwell, these works showed that in some cases Cavendish was far ahead of the science of his time. Thus as early as 1771 he came to the conclusion that the forces of electrical interaction are inversely proportional to the square of the distance between the charges (in 1785 the law of electrical interaction was established by C. Coulomb). He introduced the concept of electric capacitance. He discovered the influence of the medium on the capacitance of a capacitor and determined the permittivity of a number of substances. In 1798, with the help of a torsion balance, he measured the force of attraction between two small spheres, thereby confirming the law of universal gravitation, and determined the gravitational constant and the mass and mean density of the Earth (5.18 g/cm3). He held the view that heat is a consequence of the internal motion of the particles of bodies. In 1766 he obtained hydrogen in the pure state, established its properties, determined the composition of water and showed that it can be produced artificially, and determined the content of oxygen in air (1781). His work also concerned molecular physics, heat and mathematical physics.