Emanuel Mendes da Costa (1717-1791) is not one of the most high-profile past Fellows of the Royal Society. To the extent that he is known, it is probably not for his contributions to natural history or antiquarianism, but for his notoriety in embezzling £1,492 from the Society (equivalent to some £150,000 today) while serving as its Clerk.
In his 1944 history of the Society, Sir Henry Lyons gives a brief account of Emanuel Mendes da Costa and his career with the Society (Fellow 1747, Clerk 1763, ejected December 1767) and, while conceding that he ‘appears to have been an able man with various interests’, judges the choice of da Costa as Clerk ‘an unfortunate one’ and moves swiftly on. But then Lyons may not be entirely reliable: he also identified the Fellow Moses da Costa as Emanuel’s father, and his grandfather as the physician to ‘Queen Charlotte when she came from Portugal’; Moses da Costa was in fact Emanuel’s cousin, and the Queen (to whom his great-uncle was indeed physician) was Catherine of Braganza. The Jewish historian Albert Hyamson is similarly dismissive, saying that, although da Costa was ’eminent as conchologist, mineralogist, antiquary, and naturalist in general … unfortunately his character was weak.’
Recent scholarship has been no kinder. Dr Geoffrey Cantor writes of da Costa in pathological terms as ‘A severe case of philosophical dropsy’, while Dr George Rousseau writes that ‘Little is known about da Costa’s early life or education and, despite the vast archive of extant correspondence … He emerges from relative obscurity, and after a brief moment of renown followed by ignominy, returns to it.’ He nevertheless proceeds to a thorough character assassination of da Costa as a criminal and pathological obsessive, subject to a psychological need for excess consumption and acquisition. Rousseau ties this rather uncomfortably to da Costa’s status as (quoting a contemporary) ‘The little Jew of Crane Court’.
It took the great essayist Stephen Jay Gould to see that there might be more of value in the ‘vast archive’ of correspondence that da Costa left behind him. In his 1998 short piece on da Costa, delightfully titled ‘The clam stripped bare by her naturalists, even’, he suggested in a footnote that the da Costa volumes were ripe grounds for a PhD project. I am pleased to say that this hint was taken up by Professor Anna Marie Roos at the University of Lincoln, who, with the invaluable support of the Royal Society’s Librarian Keith Moore, has made possible my present research into the work of da Costa as an Arts and Humanities Research Council (AHRC) funded project.
Besides a number of papers printed in the Philosophical Transactions and his four published works – A Natural History of Fossils (1757), Conchology (1770), Elements of Conchology (1776) and The British Conchology (1778) – da Costa left behind the large archive mentioned above. There are 12 volumes of correspondence (both da Costa’s drafts and the replies of his 300-plus recipients), giving a total of almost 3000 letters from the period 1745-1788. His correspondents include famous naturalists like Linnaeus and Buffon, as well as obscure provincial amateur collectors, and they range from Sweden to Sicily and from South Carolina to St Petersburg, testifying to the remarkable international reach of scientific networks in the early modern period. These volumes are now in the British Library, but other manuscript material is scattered in archives from Warwick County Records Office (a further volume of correspondence with Thomas Pennant) to the Freemasons’ Library, the Royal College of Surgeons (Da Costa’s seven-volume description of his extensive collection of fossils) and other repositories.
I’ve spent the last two years sifting through these records, deciphering handwriting by turns ornate, blotched, cramped, curious, arthritic or barely legible, in English, Portuguese, Spanish, French, Italian, Hebrew and Latin, and tabulating the resulting details of the correspondence for analysis. I hope I’m now in a position to make da Costa’s life and work deservedly better known, and to understand how his identity as a Jew of Portuguese descent and as a Fellow of the Society of Antiquaries and the Royal Society allowed him to build up this extraordinary international network of exchange, both of letters and material specimens.
This coming year will see me take up a very exciting Digital Fellowship with the Early Modern Letters Online project at the Bodleian Libraries, Oxford, part of the wider Cultures of Knowledge initiative using digital methods to reassemble and interpret early modern correspondence groups. It is to be hoped that da Costa’s letters can be integrated into their database, opening up possibilities of understanding his networks in new ways, as well as making the correspondence accessible to a much wider circle of scholars and researchers. Some of the fruits of this research will be put on display in an exhibition at the Royal Society in November 2019, accompanied by an online presentation on the Society’s Google Arts & Culture site, to be prepared with the (much appreciated) help of the Society’s Digitisation Project Manager, Louisiane Ferlier.
Perhaps my most exciting discovery to date, however, has been the hitherto-hidden face of my research subject. Amongst a collection of disregarded family papers now in the London Metropolitan Archives, I came across a folded charcoal portrait of da Costa himself. It was in too fragile a condition to be opened, and so I’ve had to wait some time to meet Mr da Costa personally. The portrait is presently undergoing conservation treatment funded by the AHRC, and will be ready for its first public exhibition at the Royal Society in November. In the meantime I’ve been allowed to publish the portrait in its present state, and so I give you: Emanuel Mendes da Costa FRS, FSA, Clerk and Librarian of the Royal Society and Keeper of the Repository: