John Frederick Daniell, an English physicist, born in London, March 12, 1790, died there, March 13, 1845. He was a pupil of Brande, and afterward began business as a sugar refiner. In 1816 he founded, in connection with Prof. Brande, the "Quarterly Journal of Science," of which they published the first 20 volumes. In 1820 he published a description of a new hygrometer, by which for the first time regular and accurate observations on the dryness and moisture of the air were made practicable. His great work, "Meteorological Essays" (1823), was the first attempt to explain the principles of meteorology by the general laws regulating the temperature and constitution of gases and vapors. One of the most interesting of his theories was that by which he accounted for the horary oscillations or periodic daily rise and fall of the barometer, and predicted a fall near the poles coincident with the rise at the equator, a conjecture afterward confirmed by observation. In 1824 he published an essay on "Artificial Climate," and about the same time became managing director of the continental gas company. He also invented a process for extracting inflammable gas from resin. On the establishment of King's eollege in 1831 he was appointed professor of chemistry, which office he held until his death.
About 1831 he published an account of his new pyrometer for measuring high temperatures, such as are employed in fusing metals, in furnaces, etc. Thenceforth he gave his attention principally to voltaic electricity. In 1836, in a paper communicated to the royal society, he described his improvement in the voltaic battery, by which he showed how a powerful and continuous current may be kept up for an unlimited period. In 1839 appeared his "Introduction to Chemical Philosophy," a treatise on the molecular forces. He was the only person who ever received the three medals in the gift of the royal society, of which he was a zealous member, and for the last six years of his life foreign secretary. He expired suddenly of apoplexy.