The apparatus was used by Cavendish for making and collecting hydrogen.
Why is Cavendish famous? Henry Cavendish determined the value of the universal constant of gravitation, made noteworthy electrical studies, and is he also given credit for the discovery of hydrogen and the composition of water. He discovered Hydrogen in 1766 in London. Background Henry Cavendish was born in Nice, France, on October 10, 1731. He was the oldest son of Lord Charles Cavendish and Lady Anne Grey, who died a few years after Henry was born.He never married and was so reserved that there is little record of his having any social life except occasional meetings with scientific friends. Cavendish went back to London, England to live with his father. There, Cavendish built himself a laboratory and workshop. When his father died in 1783, Cavendish moved the laboratory to Clapham Common (a district in south London) , where he also lived. Contributions to Chemistry At the time Cavendish began his chemical work, chemists were just beginning to recognize that the "airs" that were evolved in many chemical reactions were clear parts and not just modifications of ordinary air. Cavendish reported his own work in "Three Papers Containing Experiments on Factitious Air" in 1766. These papers added greatly to knowledge of the formation of "inflammable air" (hydrogen) by the action of dilute acids (acids that have been weakened) on metals. In 1766 he found a gas over mercury and referred to it as "inflammable air from the metals". He published his findings to the Royal Society the same year. Since he was the first to discover hydrogen he was credited with the discovery. The name Hydrogen came from the Greek words hydro and genes, which together mean "water forming." Cavendish's other great achievement in chemistry is his measuring of the density of hydrogen. Cavendish also investigated the products of fermentation, a chemical reaction that splits complex organic compounds into simple substances. He showed that the gas from the fermentation of sugar is nearly the same as the "fixed air" characterized by the compound of chalk and magnesia (both are, in modern language, carbon dioxide). One of Cavendish's researches on the current problem of combustion (the process of burning) made an outstanding contribution to general theory. In 1784 Cavendish determined the composition (make up) of water, showing that it was a combination of oxygen and hydrogen.