# Dictionary of National Biography, 1885-1900/Liddel, Duncan

​LIDDEL, DUNCAN (1561–1613), mathematician and physician, born in 1561, was a native of Aberdeen. Having received an education in languages and philosophy at the school and university of that town, he went abroad at the age of eighteen to seek his fortune. After a few months' wandering he arrived at Frankfort-on-Oder, where a Scotchman, John Craig (d. 1620) [q. v.], was engaged in teaching logic and mathematics. Craig received him kindly and superintended his studies. Three years later Craig returned to Scotland, and Liddel, by his advice, removed to the university either of Wratislaw or Breslau in Silesia, where he studied mathematics under Paulus Wittichius. In 1584 he returned to Frankfort, took pupils in mathematics and philosophy, and applied himself to the study of physic. In 1587 an epidemic drove him to Rostock, where he became the friend of Caselius and Brucæus, and received the degree of master in philosophy. He had hardly returned to Frankfort once more in 1590 when he was persuaded to attach himself to the new university of Helmstadt, established by Duke Julius of Brunswick. Caselius had already been appointed to the chair of philosophy there. Next year Liddel obtained the lower mathematical chair vacated by Parcovius, and in 1594 he succeeded Erhardus Hoffmann in the higher mathematical chair. In 1596 he became M.D. of the university, and began publicly to teach physic and to act as præses at the recitation of medical dissertations. In 1599 he was dean of the faculty of philosophy; in 1603 he resigned his mathematical professorship, and in 1604 became pro-rector of the university. Three years later he returned to Scotland with a competent fortune. In 1612 he endowed the university of Aberdeen with lands for the education and support of six poor scholars, ​and in 1613 he endowed a professorship of mathematics in the Marischal College. He died on 17 Dec. 1613, in the fifty-second year of his age, and bequeathed his books and instruments to the Marischal College. A brass memorial figure of him was afterwards set up in St. Nicholas Church, Aberdeen.
As a mathematician he enjoyed considerable fame in Germany, where he is said to have been the first to teach the astronomy of Copernicus and of Tycho Brahe side by side with the Ptolemaic hypothesis. He was the author of several medical books which were in high repute. Their titles are: 1. ‘Disputationum Medicinalium Liber,’ Helmstadt, 1605; medical theses maintained by himself and his pupils, 1592–1605: the volume is dedicated to Craig. A posthumous edition, under the title ‘Universæ Medicinæ Compendium,’ was published at Helmstadt in 1720. 2. ‘Ars Medica,’ Hamburg, 1608, in five books—I. ‘De Medicinæ Definitione et Principiis;’ II. ‘De Physiologia;’ III. ‘De Pathologia;’ IV. ‘De Signorum Doctrina;’ V. ‘De Therapeutica:’—dedicated to James I. Another edition was published at Lyons in 1624 by Serranus; and in 1628 a third edition appeared at Hamburg, from a copy corrected and enlarged by the author. 3. ‘De Febribus Libri tres,’ Hamburg, 1610; republished by Serranus with the ‘Ars Medica’ in 1624. 4. ‘Tractatus de Dente Aureo,’ Hamburg, 1628, an exposure of a supposed miracle—a boy having a golden tooth—which had imposed on the credulity of Horstius, one of Liddel's colleagues at Helmstadt. 5. ‘Artis Conservandi Sanitatem Libri duo,’ Aberdeen, 1651; edited by Dr. D. P. Dun.
[The main authority for the facts of his life is a letter of Caselius to John Craig, dated May 1607, and prefixed to the Ars Medica. A sketch of his life (with portrait), by Professor Stuart, appeared at Aberdeen in 1790. He is briefly noticed in Burton's Scot Abroad, p. 304.]
C. P.