# Dictionary of National Biography, 1927 supplement/Roscoe, Henry Enfield

​ROSCOE, Sir HENRY ENFIELD (1833–1915), chemist, was born in London 7 January 1833. His father, Henry Roscoe [q.v.], judge of the court of Passage, Liverpool, was the youngest son of William Roscoe [q.v.], banker, well known for his biographies of Lorenzo de' Medici and Pope Leo X; his mother, Maria, daughter of Thomas Fletcher, a Liverpool merchant, was granddaughter of William Enfield [q.v.], the last rector of the Warrington Academy. Roscoe began his scientific training at the high school of the Liverpool Institute under W. H. Balmain, known for his ‘luminous paint’. In 1848 he entered University College, London, and worked in the Birkbeck laboratory under Alexander William Williamson [q.v.] who, on succeeding Thomas Graham [q.v.] as professor of chemistry, appointed Roscoe his assistant. Gaining his B.A. degree with honours in chemistry in 1852, Roscoe proceeded to Heidelberg to work under R. W. von Bunsen, and on graduating Ph.D. in 1854 began his long research with Bunsen on the measurement of the chemical action of light. The reaction chosen was the gradual union of hydrogen and chlorine under the influence of light, originally observed by John Dalton [q.v.]. This had been investigated in 1843 by John William Draper [q.v.], who had demonstrated the initial ‘inert period’ and its abolition by the sun shining on the chlorine standing over water previous to its mixture with hydrogen. Bunsen and Roscoe made many experiments without being aware of Draper's work; on learning of it they repeated his experiment on the abolition of the inert period and found that ‘insolated’ chlorine, when mixed with hydrogen over water, still exhibited ‘photo-chemical induction’. This delay was afterwards proved to be due to a minute trace of an ammonia compound which had been destroyed in Draper's experiment. By the preparation of a standard photographic paper Roscoe secured a ready means of comparing the light of the sun at different altitudes, and of measuring the diffused light from the sky.
Soon after Roscoe's return to England he was elected (1857) to the chair of chemistry vacated by (Sir) Edward Frankland at the Owens College, Manchester. He came to Manchester when the college (opened in 1851) had reached its lowest ebb, but he grasped the great need for scientific education in an industrial centre, and the success of the chemistry school under Roscoe was a large factor in the rise of the college in efficiency and public estimation.
Roscoe's most important contribution to chemistry was the preparation of pure vanadium, and the proof which he gave from the study of its oxides and chlorides that vanadium was a member of the phosphorus-arsenic family, and not related to chromium as J. J. Berzelius had supposed. The new atomic weight assigned by Roscoe to vanadium fitted it for its rightful place in the fifth group when D. I. Mendeléeff published his Periodic System (1869). Roscoe's Lessons in Elementary Chemistry (1866) passed through ​many editions in England and abroad, and the inorganic portion of his Treatise on Chemistry (1877), written with Carl Schorlemmer, has been revised through several editions and remains a standard work. From a study of Dalton's laboratory note-books he published (with Dr. Arthur Harden) A New View of the Origin of Dalton's Atomic Theory (1896), showing that the law of multiple proportions was not the genesis but the sought-for confirmation of the idea of chemical atoms.
Roscoe was active in founding the Society of Chemical Industry (1880) and was its first president; he was also president of the Chemical Society (1881–1883), and of the British Association at Manchester in 1887. From 1878 he forwarded the movement to make the Owens College a university for Lancashire, but the opposition of other interests led to the establishment (1880) of the federal Victoria University, to which the Liverpool and Leeds colleges were afterwards admitted. In 1903–1904 the federated colleges received separate charters. Appointed vice-chancellor of London University in 1896, he took an active part in its reconstitution. The same year he became chairman of the 1851 Exhibition scholarship committee; in 1901 he joined the executive of the Carnegie Trust.
Roscoe served on the royal commission on technical instruction (1882–1884) which led to the Technical Instruction Act of 1889 and to the partial appropriation of the ‘whiskey money’ to technical education. Knighted for his services in 1884, he was elected M.P. in the liberal interest for South Manchester in 1885 and resigned the chair of chemistry at Owens College. Roscoe promoted legislation on ventilation in weaving-sheds, on sewage disposal, and on the legalization of the metric system; he asked for and served on a commission to report on Pasteur's treatment of hydrophobia, and from the first was a governor of the Lister Institute. In 1895 he began experimenting on the intermittent filtration of sewage—a process that has been largely adopted. He was made a privy councillor in 1909.
Roscoe married in 1863 Lucy (died 1910), daughter of Edmund Potter, M.P.; one son and two daughters were born of the marriage. He died at Woodcote, his summer home near Leatherhead, Surrey, 18 December 1915.
[The Life and Experiences of Sir Henry Enfield Roscoe, written by himself, 1906; Journal of the Chemical Society, 1916; personal knowledge.]
H. B. D.
ROSS, MARTIN (pseudonym), novelist. [See Martin, Violet Florence.]