WOLLASTON, WILLIAM HYDE (1766-1828), chemist and natural philosopher, was born at East Dereham, in Norfolk, on August 6, 1766, the second of seventeen children. His father, the Rev. Francis Wollaston, rector of Chisleburst, grandson of William Wollaston noticed above, was an enthusiastic astronomer. Wollaston studied at Caius College, Cambridge, of which he remained a fellow until Isis death. He took the degree of ALB. in 1787, and that of M.D. six years later, and commenced to practise medicine in 1789 at Bury St Edmunds. Failing to make headway he removed to London, where he was equally unsuccessful. He applied for a vacant physician-ship at St George's Hospital, but was not appointed ; and he never got over the feeling of irritation, which indeed led him to abandon medicine altogether. Wollaston betook himself to original research, and for a time ranged pretty impartially over the sciences. Ile is said to have accumulated a fortune by the manufacture of platinum and of various optical and mechanical inventions. He devoted much attention to the affairs of the Royal Society, of which he was elected a fellow in 1793 and made secretary in 1806. For many years lie was a vice-president, but did not care to enter on competition with Sir Humphry Davy when the latter was elected president in 1820. Beyond appearing at the meetings of learned societies Wollaston took little part in public affairs ; he lived alone, conducting leis investigations in a deliberate and very exhaustive manner, but in the most rigid seclusion, no person being admitted to his laboratory on any pretext. Towards the close of 1828 he felt the approach of the fatal malady - a tumour in the brain - and devoted his last clays to a careful revisal of his unpublished researches and industrial processes, dictating several papers on these subjects, which were afterwards published in the Philosophical Transactions. On December 22, 1828, he died, as he had lived, self-possessed, stern, and silent.

Wollaston's character presents a very remarkable analogy with that of henry Cavendish : both studied all branches of science; both were highly respected by their contemporaries for intellectual power and achievements in research ; both were reserved and distant, making few friends, never acting from impulse, but occasionally displaying unexpected generosity. Wollaston's character can only he partially divined from his public actions and relations with other scientific men, and unfortunately no other data are available. A dispute as to priority in discovering electromagnetic rotation is referred to under FARADAY, vol. ix. p. 29 ; and suggestions as to the prior invention of his process of manufacturing platinum are to be found in the article PLATINUM (vol. xix. p. 190). The incidents associated with the discovery of the metal palladium were more serious than either of these. Wollaston detected this element, extracted a considerable quantity, and exposed it for sale in an instrument-maker's shop, calling attention to it by an anonymous advertisement. A chemist, Chenevix, purchased some of the metal, and concluded from a few hasty experiments that it was an amalgam of platinum. He submitted a paper to the Royal Society, which Wollaston as secretary read, after, it is said, vainly advising Chenevix to withdraw it. A controversy, supported by elaborate series of experiments, took place, and was only terminated when Wollaston acknowledged that he was the discoverer, and described the process of extraction from the ores of platinum. Chenevix was disgusted, and deserted chemistry. Yet Wollaston was a most thorough and conscientious worker : it was his extreme caution in coming to conclusions until the facts were irresistible that occasionally led him to the unfortunate method of tentative anonymous publication ; but the same quality ensured a solidity and trustworthiness in his Royal Society memoirs which make them models to subsequent investigators.

Most of Wollaston's papers deal more or less directly with chemistry, but they diverge beyond that science on all sides into optics, physiology, botany, acoustics, astronomy, and even touch on art. He discovered the metals palladium and rhodium, and proved the identity of colundthun with titanium. The minute scale on which his analytical processes were carried out was rendered possible by his extraordinary keenness of sight and neatness in manipulation.

The Royal Society awarded him a royal medal for his process of manufacturing platimum - ri work which, in its immediate effects, it is almost impossible to over-estimate. Wollaston was the first to produce the metal in a state fit to manufacture, and in quantity sufficient to make platinum crucibles generally available, thus supplying analytical chemistry with its most powerful instrument of advance. In optics his most important theoretical observation, to which, however, be gave little attention, was the discovery in 1802 of dark lines in the solar spectrum (see LIMIT, vol. xiv. p. 593), but practically the reflecting GONIOMETER and CAMERA LUCIDA (gg. v,) were of greatest value, the former supplying the crystallographer with his chief data, the latter indispensable in the development of modern microscopical research. Amongst his other papers may he mentioned those dealing with the physiology of vision, the apparent direction of the eyes in a portrait, a comparison of the light of the sun with that of the moon and fixed stars, a slide-rule for calculating chemical equivalents, sounds inaudible to certain ears, and a theory of the formation of fairy-rings.

An appreciative essay on the "Life of Wollaston" will be found in George Wilson's Religio Chettuci (1862).