Thomas Cox joined the Particular Baptist congregation in Carter Lane in December 1786, with address listed at that time as 71 Gracechurch Street (Horsleydown and Carter Lane Church Book, 1719-1808 [Metropolitan Tabernacle, London], fol. 59).  He was the husband of Elizabeth Cox, who may have maintained her membership in another congregation (possibly an Independent congregation), for she does not appear in the rolls at Carter Lane. By 1790 the Coxes had moved to St. Thomas’s Street, Borough, on the corner of High Street, where Thomas Cox operated the Medical Library. Between 1790 and 1807, Thomas Cox appeared on more than 50 imprints from his office in St. Thomas’s Street.  He published a number of medical works by Daniel Cox (most likely his brother), listed as “Chemist to his Majesty” on his title pages, but Daniel does not appear to have been involved with the publishing and selling of books from that location. It seems probably he died in 1807, for that year Elizabeth Cox assumed control of the Medical Library. Around 1815 she was joined by her son, Daniel Cox; they appeared on several imprints as “E. Cox and Son” through 1843. By that time, Elizabeth Cox had appeared on 64 imprints, usually as “E. Cox.” 

Between 1817 and 1829, Daniel Cox appeared on 30 imprints of his own, usually as “D. Cox”; with 22 of these imprints (they appeared between 1816 and 1821, with one in 1829) bearing a location of 39 High Street, Borough. This location may actually have been the same location as the St. Thomas’s Street address, since the shop appears to have been located at the intersection of St. Thomas’s Street and High Street, or it is possible Daniel worked on his own for a period of time.  Daniel Cox’s titles are almost exclusively religious, including 21 works by George Charles Smith (1782-1863), Baptist minister at Penzance, 1807-25, all printed for Cox and who served as the primary seller. Smith was present at the founding meeting of the Baptist Union in June 1812, and from 1825 to 1843 was a missionary to seaman (he founded the first Sailor’s Home in 1828). He resumed his role as minister at Penzance in 1843, remaining in that capacity until 1863.  A letter by Daniel Cox to John Rippon, his pastor at Carter Lane, dated 15 July 1816 from 39 High Street, Borough (this appears to be Daniel's primary location, with his mother and the Medical Library still around the corner in St. Thomas's Street), can be found in the The Correspondence of the Rev. John Rippon, Vol. 1, fols 291-92, British Library, Add. MS. 25386.