Henry Cavendish
Cavendish, Henry (1731 - 1810) an English chemist and physicist, was an influential scientist who made a number of important discoveries. He was the first person to show that water consisted of oxygen and hydrogen. His research included studies on electricity, hydrogen, and specific heats.
Cavendish came from an aristocratic lineage that included dukes on both sides of his family. His father, Lord Charles Cavendish, was a respected experimental scientist and a member of the Royal Society. His mother, Lady Anne Grey, died shortly after giving birth to a second son, Frederick, when Cavendish was 2 years old.
Starting at age 11, Cavendish studied at Dr. Newcome's Academy at Hackney. From 1749 to 1753, he attended St. Peter's College, Cambridge, but left without taking a degree. Cavendish was financially independent all of his life, and he received a large inheritance from a relative. Because he was independently wealthy, he never trained for a profession and was able to devote his entire adult life to scientific pursuits that interested him. His work was distinguished for its breadth and painstaking exactness. He lived for 30 years in London with his father, who had built a laboratory in their shared residence. When Lord Cavendish died in 1783, Henry moved to Clapham Common, where he remained until his death in 1810.
Little is known about Cavendish's earliest studies after he left Cambridge. In 1764, he investigated arsenic and wrote up the results for his friends. The following year, he conducted a series of experiments on heat, including the solidification of liquids and the condensation of gases, and constructed tables of specific heats. However, the results were not publicly cited until 1783. He received the Royal Society's Copley Medal for his first published paper, Three Papers Containing Experiments on Factitious Airs, in 1766. Factitious airs are gases given off by liquids or solids during chemical reactions. Cavendish studied the properties of hydrogen, carbon dioxide, and gases produced by decay and fermentation. Because he was the first to study the properties of hydrogen systematically, he is usually credited with its discovery. During the 1770's, as part of his experiments on electricity, he studied a type of electricity-producing fish known as the torpedo.
In the summer of 1781, Cavendish demonstrated that water is produced through the combustion of hydrogen and oxygen, thus proving that water is a compound and not an element. Three years later, he read his results before the Royal Society. This paper proved to be his most controversial. Shortly after, another scientist charged Cavendish with plagiarism, stating that James Watt had made this finding before Cavendish. Several instances of misdated documents gave credence to the accusations, causing scientists to argue who had the more valid claim. By 1785, the matter had been settled, and Watt and Cavendish were on friendly terms. Apparently Watt and Cavendish, working independently, had reached a similar conclusion, but Cavendish had priority and is given the credit.
Cavendish was elected to membership in the Royal Society and the Royal Society Club in 1760. He was an active participant and attended nearly every meeting. He also was a member of the Royal Society of Arts, a fellow of the Society of Antiquaries, a trustee of the British Museum, a manager of the Royal Institution, and a foreign member of the National Institute of France.
Although Cavendish is often regarded as the leading English scientist of his day, he published relatively little—fewer than 20 articles over a 50–year period. Cavendish also lived a somewhat reclusive life, communicating with his servants by notes. Shy and nervous, he was seldom seen in public except at scientific functions. A contemporary wrote that Cavendish “probably uttered fewer words in the course of his life than any man who ever lived to fourscore years, not at all excepting the monks of La Trappe.”
However after his death, it was discovered that Cavendish had left behind numerous notebooks and unpublished manuscripts on wide range of subjects not reflected in his published papers. Topics included mechanics, industrial science, magnetism, optics, geology, and pure mathematics. Perhaps the most important unpublished works were those on electricity. By the time Cavendish finished his electrical experiments in 1781, he had discovered a number of fundamental laws, including the difference between electrical quantity and potential. In 1879, physicist James Clerk Maxwell edited a volume of Cavendish's electrical investigations.
Cavendish never married. When he died, he left a sizable bequest to his relatives. The Cavendish Laboratory at Cambridge is named in his honor.