Among the Sloane manuscripts now at the British Library are papers relating to the naturalist and collector William Courten (1642–1702), whose collection at Middle Temple could be visited from around 1685. The papers contain lists of acquisitions by Courten from the late 1680s, and record dates, objects, prices and the people from whom he purchased collectable objects, both naturalia and artificialia. These lists, transcribed in an online appendix, provide evidence of his daily collecting habits and of the availability of collectable items in London; several of Courten’s suppliers were Londoners who are otherwise unknown.