This private museum is described in his 1830 catalogue as Museum Brookesianum Embracing an Almost Endless Assemblage of Every Species of Anatomical, Pathological, Obstetrical, and Zootomical Preparations, as well as Subjects in Natural History. Elected a Fellow of the Royal Society in 1819, Brookes gave up teaching in 1826, in bad health. After vainly endeavouring to dispose of his museum collection entire, he sold it off piecemeal.
The final sale took place on 1 March 1830, and on 22 following days. He died 10 January 1833, in Great Portland Street, London.