# Dictionary of National Biography, 1885-1900/Ingenhousz, John

​INGENHOUSZ, JOHN, M.D. (1730–1799), physician and physicist, was born at Breda in 1730, and educated for the medical profession. He practised for six years in the Netherlands, and came to England in 1764 or 1765. After spending more than three years in or near London, during which time he followed the new practice of inoculating small-pox in its mitigated form, which had been introduced by Dr. W. Watson at the Foundling Hospital and by Dr. Dimsdale in Hertfordshire, he was selected by Sir John Pringle in 1768 to proceed to Vienna to inoculate several members of the imperial family of Austria, Dimsdale having himself been sent for in July of that year to inoculate the Empress Catharine at St. Petersburg. Ingenhousz received early in 1769 ‘a pension for life from the emperor of nearly 600l., and was made body physician to Joseph II and Maria Theresa, and aulic councillor. He remained some years in Vienna, and set up a laboratory for physical experiments, which the emperor is said to have frequented. In his endeavours to introduce inoculation into Austria he was opposed by De Haën, then at the head of the medical school of Vienna (Hãser). In 1775 he began to send researches to the Royal Society, the first of the series having been made at Leghorn in 1773 upon the torpedo-fish, a favourite subject of study in those days. He contributed nine papers in all to the 'Philosophical Transactions,' the last appearing in 1782; five treated of electricity and magnetism, and four of the atmospheric gases. In 1779 he came back to London, and was elected F.R.S. He appears to have spent most of his remaining years in England, a prominent figure in scientific circles, always willing to show his experiments to his friends, especially considerate, it is said, to young people, and noted for his simple and kindly disposition. When on a visit to the Marquis of Lansdowne at Bowood, in the autumn of 1798, shortly after Jenner's essay on cow-pox came out, he made inquiries as to the Wiltshire milkers' experiences of the alleged protective against small-pox, and formed an opinion adverse to Jenner's contention, but confined his opposition to a private letter, and declined further controversy. He was taken ill during a visit to Bowood in the autumn following, and died there on 7 Sept. 1799. Besides his papers sent to the Royal Society, his chief work was 'Experiments on Vegetables, discovering their great Power of purifying the common Air in Sunshine, but injuring it in the Shade or at Night,' London, 1779 (French translation by the author, with additions, 2 vols., Paris, 1787-9). This contained the discovery, also ascribed to Saussure, of plants in the sunshine giving off oxygen, and in the shade carbonic acid. A collection of his papers was published at Paris, 'Nouvelles experiences et observations sur divers objets de physique,' 2 vols., 1785-9. A collection in German was published by Molitor at Vienna in 1782. His work on the ‘Respiration of Plants' also appeared at Vienna in 1786. A work in Latin, Vienna, 1795, called 'Miscellanea Physico-Medica,' edited by Scherer, is a series of his open letters to foreign savants, chiefly on questions of pneumatics. In 1796 he sent to the board of agriculture an essay on 'The Food of Plants and the Renovation of Soils.' An ​engraved portrait is prefixed to the 'Experiments on Vegetables.'
C. C.