periodicals are full of valuable scientific observation. He was elected F.R.S. in 1876, and in 1886 received from the university of Oxford the honorary degree of D.C.L. He was a vice-president of the Society of Antiquaries, and in 1881–2 president of the Anthropological Institute, of which he was an energetic supporter. On the passing of the Ancient Monuments Preservation Act (1882), he became the first inspector of ancient monuments.
Pitt-Rivers died at Rushmore on 4 May 1900. In 1853 he married the Hon. Alice Margaret, daughter of the second Baron Stanley of Alderley, and had issue six sons and three daughters, of whom the second, Alice, became in 1884 the second wife of Sir John Lubbock (now Lord Avebury).
[Journal United Service Institution, 1858, &c.; Journal Anthropological Institute; Journal of Royal Institution, 1875; Archæologia; Proceedings of Royal Soc. of Antiquaries.]
PLAYFAIR, LYON, first Baron Playfair of St. Andrews (1818–1898), was born on 21 May 1818 at Chunar, Bengal, and was the son of George Playfair, chief inspector-general of hospitals in Bengal, by his wife Janet, daughter of John Ross of Edinburgh. James Playfair [q. v.] was his grandfather; Sir Robert Lambert Playfair [q. v. Suppl.] was his younger brother.
Lyon was sent home to St. Andrews, the seat of his father's family, at the age of two, and received his early education at the parish school, from which he proceeded to the university of St. Andrews in 1832. On leaving this university, Playfair spent a very short time in Glasgow as clerk in the office of his uncle, James Playfair, and then (1835) commenced to study for the medical profession, entering the classes of Thomas Graham [q. v.] in chemistry at the Andersonian Institute in Glasgow. In 1837, on Graham's appointment to a chair in London, Playfair entered the classes of the Edinburgh University with the object of completing his medical course, but his health broke down and he was compelled to abandon his work. He then visited Calcutta, where, at his father's wish, he again entered a business house, only to leave it after a very short interval, and return to England to resume the study of chemistry. After spending some time as private laboratory assistant to Graham at University College, London, he worked with Liebig at Giessen (1839-40), where he graduated Ph.D. In 1841 he became chemical manager of Thomson's calico works at Primrose, near Clitheroe, but resigned this position in the following year, and was appointed honorary professor of chemistry to the Royal Institution, Manchester, a post which he occupied until 1845.
Playfair had visited Giessen at the moment when Liebig, at the height of his fame as an investigator and teacher, was beginning to turn his attention to the applications of organic chemistry to agriculture and vegetable physiology, and was engaged in the composition of his celebrated work on these subjects. Playfair, as Liebig's representative, presented this book to the British Association for the Advancement of Science at the Glasgow meeting (1840), as part of a report on the state of organic chemistry, and he afterwards prepared the English edition of the book. Its publication attracted the attention of scientific men interested in the rational pursuit of agriculture, to which Liebig's influence gave a great impulse. Consequently, when Playfair proposed in 1842 to apply for the professorship of chemistry at Toronto, Sir Robert Peel was induced to seek an interview with him, and persuade him to stay at home. Thenceforth constant use was made of his services in public inquiries and on royal commissions.
In 1845 Playfair was appointed chemist to the Geological Survey, afterwards becoming professor in the new School of Mines at Jermyn Street, and in this capacity was engaged in many investigations, among the most important of which were the determination of the best coals for steam navigation, and the inquiry into the condition of the potato disease in Ireland (1845).
Although Playfair returned from Giessen in 1841, inspired with something of Liebig's enthusiasm for research, the amount of purely scientific investigation which he carried out was relatively small, owing to the fact that his time was largely spent in inquiries which rather involved the practical applications of scientific principles than the discovery of new facts. His most important investigations are those on the nitroprussides, a new class of salts which he discovered; on the atomic volume and specific gravity of hydrated salts (in conjunction with Joule), and on the gases of the blast furnace (in conjunction with Bunsen). He was elected F.R.S. in 1848, and was president of the Chemical Society in 1857-9, and of the British Association in 1885 at Aberdeen, while he twice acted as president of the chemistry section of the British Association.
In 1850 Playfair was appointed a special commissioner and member of the executive committee of the Great Exhibition of 1851. He took an active part in the general organisation of the exhibition, in securing the
