Philip Joseph Hartog

“ In 1796, when his name appears in the ‘List of the Members of the Board of Agriculture,’ he lived in Leicester Square. Pearson and his colleague Woodville were among the first to recognise the value of the discovery of vaccination by Edward Jenner (1749–1823) [q. v.] , and were, indeed, the first to make experiments on a large scale in this matter. Soon after Jenner's first publications they vaccinated 160 patients, and subsequently inoculated sixty for smallpox, of whom none took the disease (20 Jan. to 17 March 1799) . ”

“ He early showed a liking for chemistry and science generally. At the age of seventeen he became clerk to a private banking firm in London, where he remained for five years, giving, however, all his leisure to scientific work. ”

“ The drawings of plants are remarkably exact. The book, which has been translated into French and German, and has become a classic, involved an immense amount of labour. Percy's work on alloys, his discovery of ‘aluminium bronze,’ and his view that in many countries the iron age preceded the bronze age, deserve special mention.
Percy was appointed lecturer on metallurgy to the artillery officers at Woolwich in 1864 (circa) (Journal of the Iron and Steel Institute, 1885, i. 8) , and retained this post till his death. ”

“ Peart in his ‘Animal Heat’ (1788) explained all chemical and physical phenomena by assuming the existence of four elements—æther, phlogiston, the acid principle, and earth. In the following year these were reduced to three, two active principles, æther and phlogiston, and one fixed. When a fixed particle is surrounded by an atmosphere of particles of æther radiating from it in straight lines, it forms an earthy (i.e. alkaline) particle; a phlogiston atmosphere producing an acid particle (The Elementary Principles of Nature, pp. 24, 285) . ”

“ He became a medical student in the university of Glasgow, where he took the degree of M.D. He first studied chemistry under Professor Penny, whose assistant he became, and subsequently entered the university of Edinburgh, where he worked under Professor Gregory. He went to Melbourne in 1855, to fill the post of lecturer on chemistry and natural science in the Scotch College of that city. ”

“ Down, was born in Dublin on 30 Sept. 1756. He was descended from Sir Philip Perceval [q. v.] , and hence related to the earls of Egmont. He entered Trinity College, Dublin, in 1772, and graduated B.A. in 1777. He then proceeded to Edinburgh, where he studied medicine, and graduated M.D. on 24 June 1780, with a thesis on the physiology of the heart. After studying two years on the continent, he returned to Dublin in 1783, when he was appointed lecturer on chemistry in the university. ”

“ Pearson sent out letters to doctors in England and abroad with regard to his work; and, in spite of the continental war, correspondence on vaccination was permitted between him and medical men in France and Italy (Gent. Mag.) On 2 Dec. 1799 a vaccine pock institution, which became the official institution for the army and navy, was established by his efforts at 5 Golden Square. He had not informed Jenner of his plan, though he eventually offered him the post of extra corresponding physician, an honour promptly declined. ”

“ Although an acute critic both of Priestley and Lavoisier, he failed to grasp the distinction made by the latter chemist between ponderable matter and caloric, and hence his constructive theories, though ingenious, were unsound and sterile, and discredited his criticisms. ”

“ His name appears as treasurer, and afterwards as vice-president, of the Geological Society in the first volumes of their ‘Transactions’ (beginning in 1811) . He was also an early member of the Mineralogical Society. He appears to have succeeded to his father's business in the Poultry, and to have extended it to philosophical-instrument making. ”

“ He will be remembered chiefly by his inauguration of popular scientific lectures, and by his popular scientific works, which, in spite of a somewhat inflated and diffuse style, are clear and interesting. ”

“ He subsequently became involved in personal controversy with his colleague, Dr. E. Hill, who was obliged, under the provisions of the act, to resign the professorship of botany, which he had held simultaneously with the regius professorship of physic. ”

“ In 1846 he worked with David Forbes (1828–1876) [q. v.] and William Hallowes Miller [q. v.] on crystallised slags. In 1847 he became a fellow of the Royal Society, and served on the council from 1857 to 1859. ”

“ Men of the Time, 11th edit.; Athenæum, 1889, i. 795; Blandford in Proc. of the Geological Soc. 1890, p. 45; Mrs. Andrew Crosse, ‘A Many-sided Man,’ in Temple Bar, lxxxix. 354, written from personal knowledge and information supplied by Percy's family; obituary in Journ. of the Iron and Steel Institute, 1889, i. 210; Times, 11 Dec. 1879, 1 Jan. 1880, and 11 and 13 Feb. 1880; Brit. Mus. Cat.; Royal Soc. Cat. of Scientific Papers; Cat. of Metallurgical Specimens formed by J. Percy, 1892. ”

“ Gent. Mag. 1856, i. 521; J. C. Poggendorff's Biogr. Lit. Handwörterbuch zur Gesch. der exacten Wissenschaften; Life of William Allen, 3 vols. 1846–7, passim; Transactions of the Geological Society, vol. i. 1811, &c.; Royal Society's Catalogue of Scientific Papers, vol. iv.; Hermann's Physiology Trans., Gamgee, p. 158; Landois and Stirling's Physiology, 1st edit. p. 259; account of the Ornithorhynchus paradoxus (belonging to W. H. P.) , Tilloch's Phil. Mag. xiii. 179, 256; and Pepys's own papers and his collection of manuscript papers relating to the Royal Institution in the Brit. Mus. Library. ”

“ Thomas's Hospital. In 1775 he travelled through France, Germany, and Holland, returning to England in 1777, and settling in Doncaster, where he became intimate with the actor John Philip Kemble [q. v.] ”