# Dictionary of National Biography, 1885-1900/Costa, Emanuel Mendes da

​COSTA, EMANUEL MENDES da (1717–1791), naturalist, was the sixth but second surviving son of Abraham, otherwise John, Mendes da Costa, a Jewish merchant who lived in the parish of St. Christopher-le-Stocks, London. He was born on 5 June 1717, and, being intended for the lower branch of the legal profession, served his articles in the office of a notary (Gent. Mag. vol. lxxxii. pt. i. pp. 22–4). From his early years he had applied himself with enthusiasm to the study of natural history; the branches he most excelled in were conchology and mineralogy. In November 1747 he was elected a fellow of the Royal Society, and from that period until his withdrawal in 1763 he enriched the ‘Philosophical Transactions’ with many papers upon his favourite studies. He was admitted fellow of the Society of Antiquaries on 16 Jan. 1751–2, and was also a member of several other scientific associations, English and foreign. Although he early obtained the reputation of being one of the best fossilists of his time, and was in correspondence with many of the most celebrated naturalists of Europe, his life appears to have been a continual struggle with adversity. In 1754 ​we find him imprisoned for debt, and his cabinets held in bond (A Selection of the Correspondence of Linnæus, &c., edited by Sir J. E. Smith, ii. 482–3). Upon his release in the following year he set about preparing for the press his long-promised ‘Natural History of Fossils,’ the proposals for which had been issued in 1751. Of this work vol. i., part i., appeared in 1757, but no more was published, the author not finding or deserving encouragement. Through the benevolent efforts of Dr. Stukeley, Peter Collinson, and other scientific friends, Da Costa was elected to the clerkship of the Royal Society on 3 Feb. 1763, in place of Francis Hauksbee, deceased. He had held the appointment barely five years, when, being detected in various acts of dishonesty, he was summarily dismissed in December 1767, and shortly afterwards arrested at the suit of the society and committed to the king's bench prison. His library and collections were seized and sold by auction in the following May. He continued a prisoner until the end of 1772, supporting himself by his pen and lecturing, but was frequently in want. We next hear of him in 1774, when he petitioned to be allowed to read a course of lectures on fossilology to the university of Oxford in the ensuing Act term; but his reputation had preceded him, and permission was peremptorily refused. Towards the close of his life he resumed authorship with some success. He published ‘Elements of Conchology; or an introduction to the Knowledge of Shells,’ 8vo, London, 1776, and ‘Historia naturalis Testaceorum Britanniæ, or the British Conchology, containing the … Natural History of the Shells of Great Britain and Ireland … in English and French,’ 4to, London, 1778. He also revised and contributed additional notes to Engeström's translation of Cronstedt's ‘Essay towards a System of Mineralogy,’ 8vo, London, 1770 (second edition, enlarged by J. H. de Magellan, 2 vols. 8vo, London, 1788). In these undertakings he was greatly assisted by his steady friends Dr. John Fothergill and Dr. Richard Pulteney. Da Costa died at his lodgings in the Strand in May 1791, and was buried in the Portuguese Jews' cemetery at Mile End (Will. reg. in P.C.C., June 1791; Lysons, Environs, iii. 478). He was twice married: first, in March 1750, to his cousin Leah, third daughter of Samuel del Prado, who died in 1763, leaving no issue; secondly, about 1766, to Elizabeth Skillman, or Stillman, by whom he had an only daughter. Many of his manuscripts are preserved in the British Museum; the more important are: his letters to and from scientific friends, which cover a period of fifty years (1737–1787), in Addit. MSS. 28534–44 (a few are printed in Nichols, Literary Illustrations, vol. iv.); ‘Commonplace Book,’ in Addit. MS. 29867 (portions of which appeared in Gent. Mag. vol. lxxxii. pt. i. pp. 205–7, 513–17); ‘Collections relating to the Jews,’ in Addit. MS. 29868 (portions in Gent. Mag. vol. lxxxii. pt. ii. pp. 329–31); ‘Minutes of the Royal Society and Society of Antiquaries, 1757–1762,’ in Egerton MS. 2381. Da Costa also mentions his ‘Athenæ Regiæ Societatis Londinensis,’ in three folio volumes, which he presented to the society's library in 1766; but of this all traces have disappeared.
[Nichols's Lit. Anecd. ii. 292, iii. 233, 757, v. 712, vi. 80, 81, viii. 200, ix. 607, 799, 812, 813, 816; Gent. Mag. lxxxiii. (pt. i.) 429, new ser. xxvi. 493; Quarterly Rev. cxxxix. 391; Munk's Coll. of Phys. (1878), ii. 156.]
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