Dictionary of National Biography, 1885-1900/Delaval, Edward Hussey
DELAVAL, EDWARD HUSSEY (1729–1814), chemist, was a member of an ancient Northumbrian family, represented by two branches at Ford and at Seaton in that county. He was born in 1729, being a younger brother of Lord Delaval, a title now extinct. On Lord Delaval's death in 1808 he succeeded to his entailed estates at Seaton-Delaval and Doddington. Edward took the degree of M.A. and became a fellow of Pembroke Hall, Cambridge. His classical attainments were considerable, and he was conversant with many modern languages. His favourite pursuit, however, was the study of chemistry and experimental philosophy. Having been elected a fellow of the Royal Society (December 1759), he contributed to their ‘Transactions’ in 1764 an account of the effects of lightning in St. Bride's Church, Fleet Street, with explanatory plates. Five years later he was appointed with Benjamin Franklin and others to report to the Royal Society on the means of securing St. Paul's Cathedral against danger from lightning. On 22 March 1772 St. Paul's was struck with lightning, and Delaval, after examination, gave an account of the effects produced. In a controversy which arose as to the use of pointed or blunt lightning-conductors Delaval (February 1773) gave excellent reasons for using blunt conductors in buildings of ordinary size. Following up Sir Isaac Newton's treatise on optics Delaval experimentalised on the specific gravities of the several metals and their colours when united to glass, and wrote a paper on the subject (Phil. Trans. lv.), for which he received the Royal Society's gold medal. The subject was further developed in a quarto volume on ‘The Cause of Changes in Opaque and Coloured Bodies,’ which he published in 1777. Seven years later he obtained the gold medal of the Manchester Literary and Philosophical Society for a paper on ‘The Cause of the permanent Colours of Opaque Bodies’ (Memoirs, ii.) These various scientific writings attracted the notice of many European inquirers, and were translated into several foreign languages. He was elected member of the Royal Societies of Göttingen and Upsala, and of the Institute of Bologna.
Among Delaval's minor achievements were the manufacture, under his direction, of the completest set of musical glasses until then known in England. He also manufactured artificial gems, and devised a method of abstracting the fluor from glass, of which he left some curious samples. The house in Parliament Place, near the Thames, in which he lived till his death, was lined, under his direction, with artificial stone as a preservative against fire. His death took place on 14 Aug. 1814 in his brother's house.
A list of his papers will be found in the index to ‘Philosophical Transactions,’ published by Dr. Thomas Young. The ‘Inquiry into the Cause of Changes in Opaque and Coloured Bodies’ was published in London, 4to, 1777, and a second edition at Warrington, 8vo, 1785.
[Philosoph. Mag. xlv. 29; Dr. Thomas Young's index to Phil. Trans. in his Course of Lectures, 4to, 1807.]