Daniell, John Frederic

(b. London, England, 12 March 1790; d. London, 13 March 1845)

meteorology, chemistry, electricity.

The eldest son of George Daniell, a bencher of the Middle Temple, John received an extensive private education in the classics, after the fashion of the prosperous professional classes of late Georgian London. Even so, his predilection for natural and experimental philosophy was apparent from an early age. He eventually found his métier in a blending of useful observation and elegant codification, and in pioneering improvements in instruments and procedures across a wide spectrum of scientific activity. In this respect his life reflects the rapid advances in technical sophistication of the still imperfectly differentiated physical sciences. His teaching, administrative, and governmental work illuminates other facets of the research enterprise in the early nineteenth century. At that time the polite Anglican professionalism which he exemplified was an important mediating force between the declining dilettante tradition of natural philosophy and the more aggressive self–interest of the often provincial and Dissenting autodidacts and entrepreneurs of newly self–conscious science.

As a young man Daniell joined the sugar–refining business of a relative. Improvements in the manufacturing process were one outcome. Of more importance to Daniell was his acquaintance and resulting lifelong friendship with William T. Brande, professor of chemistry at the Royal Institution. Together they made several scientific excursions both in Britain and on the Continent, And in 1816 they revived the defunct journal of the Royal Institution, jointly conducting twenty issues. These contain many of Daniell’s early papers, principally on the phenomena of crystallization and other chemical subjects.

In September 1817 Daniell married Charlotte, youngest daughter of Sir William Rule, surveyor of the navy. She bore him two sons and five daughters. Her death in 1834 was a deep blow to Daniell, a man of reserved manner and warm family attachments. As a consequence of his marriage, Danniel became managing director of the Continental Gas Company, formed to profit from the technological lead enjoyed by the new British lighting industry. He visited various French and German cities to suggest plans for their illumination. Characteristically, he was also soon at work on a new process to generate gas by the destructive distillation of resin dissolved in turpentine. This process saw considerable success in place where coal was expensive, notably in New York and some other American cities. Despite his obvious gifts for such manufacturing enterprises, Daniell found administration, teaching, and research in theoretical aspects of science more congenial to his tastes.

In 1820 he published a description of a new dewpoint hygrometer. Its operation depended on the rapid indirect cooling and slow reheating of a glass bulb, the mean between the temperatures at which moisture first appeared and last disappeared from the surface of the bulb being taken as the dew point. This hygrometer enjoyed wide popularity and quickly became a standard instrument.

In 1823 Daniell collected and published his various Meteorological Essays. Extending and codifying current knowledge, the work had a considerable success, reaching a third edition in 1845. His wide–ranging interests are also revealed in an important 1824 paper to the Horticultural Society, pointing out the necessity of maintaining an appropriate humidity as well as temperature in any hothouse. He was awarded a silver medal for this contribution. In the Philosophical Transactions of the Royal Society for 1830 he published an account of a new pyrometer for ascertaining the heats of furnaces. Together with a second paper showing additional applications of the new pyrometer, this work won him the Rumford Medal of the Royal Society (1832).

Daniell’s technical ingenuity and love of new instruments also led to the devising of a plan for an elaborate water barometer with which to study more accurately the fluctuations in atmospheric pressure. The Royal Society commissioned him to build such an instrument, which functioned only erratically. Nothing daunted, Daniell moved to new fields and in 1835 begun the work with which his name is most frequently connected.

Research in the still new field of current electricity was at this time hindered by the rapid decline in power of the voltaic cell when in use, because of “reverse polarization.” Investigating the standard zinc–copper battery, he found that the decline in power was caused by the liberation of hydrogen gas on the copper plate during electrolysis. In an 1836 Philosophical Transactions paper he therefore proposed a new form of apparatus (known familiarly as the Daniell cell) to prevent such liberation and thus maintain a continuous and even current. In this apparatus the zinc and its attendant dilute sulfuric acid are separated from the opposite copper electrode and a solution of copper sulfate by a porous barrier, such as a piece of ox gullet. This arrangement effectively prevents the formation of hydrogen gas at the copper electrode and thus enables the battery to function unimpaired for long periods of time.

The use of such cells, often coupled together in long chains to give a large electromotive force, gave great impetus to research in all branches of current electricity and also led to commercial applications in gilding, electroplating, and glyphography. Daniell himself went on to publish a series of papers on various more theoretical aspects of electrochemistry. He investigated the wide–ranging applicability of Ohm’s law. He also showed that the ion of the metal, rather than of its oxide, is the carrier of the electric charge when a metal–salt solution is electrolyzed. These researches served to confirm Daniell’s skill as an experimenter, but it was the actual construction of the new battery which won him the Copley Medal, the Royal Society’s highest award, in 1837.

While active in scientific research and invention all his life (he published more than forty original papers), Daniell also worked vigorously as a popularizer and teacher. He was one of the originators of the society for Promoting Useful Knowledge (1827), writing and editing several of the early works of the society, including their treatise on chemistry. His early papers on crystallization had already established his reputation as a chemist. In combination with his social standing and religious and political views, this reputation made him an obvious choice as first professor of chemistry at the newly established King’s College, London, in 1831. For the rest of his days he devoted great effort to his teaching there, developing careful and elaborate experimental illustrations for his lectures. He also supervised a practical class and gave private instruction in laboratory technique. This teaching work led naturally to his elegant Introduction to the study of chemical philosophy (London, 1839), dedicated to his admired friend Michael Faraday. Among its other successes, the book was edited and adapted for the more than 5,000 schools of New York State within a year; a second English edition appeared in 1843.

Daniell was continuously active and influential in the affairs of King’s College, being largely responsible for the establishment of its department of applied science. A man of such eminent talent and judicious personal views was also much in demand as the calls and pressures on national scientific activity increased and multiplied in the 1830’s. He was early involved with the scientific aspects of what became Commander Ross’s 1839–1843 Antarctic expedition. He was largely responsible for the meteorological parts of the associated Royal Society report of 1840 on establishing and equipping magnetic and meteorological observatories in the British dominions. In 1839 he was appointed to an Admiralty commission on defending ships from lightning. He also supplied advice on the continual and troubling problem of the corrosion of the copper sheathing of ships on the African station. His report was published in the Nautical Almanac for 1841. In that same year Daniell was actively involved in the formation of the Chemical Society of London, serving as a vice–president.

Civil recognition of his abilities came in the form of an Oxford D. C. L. in 1842. The Royal Society itself also recognized the talent of this loyal, active, and scientifically gifted member, and he served as its foreign secretary from 1839. His sudden death, while at a meeting of the Council of the Society, left a considerable gap in the ranks of scientist–administrators. His importance in the changing and professionalizing science of his days was well caught by an obituarist who observed that the “habits of business he acquired in early life, and his extensive intercourse with men in general, added to his natural perspicacity, gave him a clear insight into character, and conferred on him advantages which men of science in general do not possess.”

BIBLIOGRAPHY

Listings of Daniell’s many publications may be found in the Royal Society Catalogue of Scientific papers and on pp.xxxiii–xxxv of the third edition of his meteorological essays, published as Elements of Meteorology, 2 vols.(London,1845). This latter also contains an interesting obituary (PP. xiii–xxxii), as does proceedings of the Royal Society (London), 5 (1845),577–580. His hygrometer and water barometer are discussed respectively in W. E. K. Middleton’s Invention of the Meteorological Instruments (Baltimore, 1964) and history of the Barometer (Baltimore, 1969). The Daniell cell and the electrical researches are extensively treated in vol. IV of J. R. Partington’s History of Chemistry (London, 1964).

Arnold Thackray