After his death on 11 January 1753, George II proved indifferent to the purchase, and rather than offering the collection to the Royal Society or one of the other bodies specified in the will, Sloane's trustees decided to petition parliament to purchase the collection for the nation.
Sloane's former curator, James Empson, estimated the collection's value as between £80,000 and £100,000, and parliament voted to buy it, along with Sloane's library of books and manuscripts and manuscripts collected by the Harleys, first and second earls of Oxford.
An act of parliament on 7 June 1753 combined Sloane's 50,000 volumes and 3,560 manuscripts, including tracts on science and medicine, collected letters and papers and the collector's voluminous correspondence, with the Harleian collections and documents left to the nation in 1700 by Sir Robert Cotton, to form the founding collection of the British Museum.
Sources: Chambers Biographical Dictionary; Robert Huxley, Sir Hans Sloane: 350 years of preserving history; L.E. Elliott Joyce, Lionel Wafer and His Times; M. McCarthy, A Brief Dampier Chronology; Arthur MacGregor, Sir Hans Sloane baronet (1660–1753); Wikipedia