Da Costa came from a
Sephardi family that had moved to
England in the 1600s from
Portugal. His parents were Abraham and Esther. Abraham is thought to have been in the
diamond trade business. One of his brothers became a wealthy businessman. Emanuel worked in the office of a
notary and qualified while working for the
Scriveners' Company in 1762. Da Costa pursued his interest in
natural history from around 1736 onward. He began to trade in
seashells,
corals and
fossils. He corresponded with
Carl Linnaeus,
Hans Sloane, and other naturalists of the period. Da Costa was elected one of the first
Jewish Fellows of the
Royal Society in 1747, sponsored among others by
Martin Folkes. In 1750, da Costa married Leah, whose brother Abraham del Prado was a wealthy contractor for the English army, supplying food. Around 1740, Abraham had employed da Costa in the
Netherlands but this led to unpaid
debts and resulted in da Costa's imprisonment for two years. In 1763, the death of
Francis Hauksbee, who had served for forty years as clerk to the Royal Society, led to an opening that he bid for by enlisting the votes and endorsements from his friends and correspondents. He was appointed simultaneously as
clerk,
librarian, keeper of the
repository and
housekeeper for the Royal Society. But in 1767 he was discovered to be withholding members' subscription fees, was convicted of
fraud, and sentenced to five years in
debtors' prison. The
evidence was detected when
John Hope was listed as an annual instead of a perpetual member and sought an
investigation of the matter. Da Costa released the annual membership fees to the Royal Society while profiting personally from
interest incurred on the remainder of the life membership subscriptions. After his release from prison, he struggled to make a living lecturing about fossils and dealing in shells and
minerals. His last scientific publication was
British Conchology (1778), which included an autobiographical preface. Some friends remained loyal even after his imprisonment. These included Ingham Forster (1725-1782), brother of Jacob Forster (1739-1806). Da Costa died in his home in the Strand and was buried in the Bethahaim Velho, 243 Mile End Road, London. Da Costa was also a fellow of the
Antiquarian Society of London from 1752; a member of the Botanic Society in Florence (
Società botanica fiorentina), the
Aurelian Society, and the
Gentleman's Society at Spalding. He was married twice, first to Leah, who died in 1763 without issue. His second wife, Elizabeth Skillman, outlived him and they had a daughter. ==Works==