The collection consists of two series:

Letter from Henry Thomas Colebrooke to Nathaniel Wallich in which he thanks Wallich for his correspondence and his Geological and Botanical Despatches and for Mr D Scott's remarks. He enquires whether Scott would like to be a member of the Geological Society. He writes of Limestone specimens that Wallich sent and of that he is pleased that the Gayal cattle have not been sent. He suggests that Wallich might write to his relative, Mr James Gosling, at the Cape of Good Hope who would be happy to try any specimens in his garden that Wallich thinks could flourish there. He asks about various species and botanical drawings. Handwritten, dated 8 September 1819, received 16 March 1820.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich, pleased to hear that Wallich has resumed his role at the Botanic Gardens and thanking Wallich for his responses to Colebrooke's previous inquiries. He thanks Wallich also for sending seeds and that the plants that he sent are doing well at Kew. He asks if more can be sent. Wallich will be proposed for the Linnean Society after the Easter break and can also be proposed to the Geological Society. Colebrooke is keen to promote study on the geology of India and states information that he would like to collect. Colebrooke is pleased that Wallich is in contact with Mr Alexander of the Cape of Good Hope. He is also contemplating whether the "Gayal" would be suitable cattle for Cape of Good Hope and England and is looking into the possibility of shipping some heifers and steers. Handwritten, dated 18 March 1818, with Wallich's dating, arrived 28 July by Marchioness of Ely, answered 29 July by [Oriton]

"H.T. Colebrooke - Memoirs and Autographs", A red calf bound book, containing printed and handwritten material including biographical material concerning Colebrooke, obituary notices for Horace Hayman Wilson, and correspondence from Colebrooke to Nathaniel Wallich. On the inside cover there is a bookplate with "Ex Libris Frederick Hendricks, F.S.S., F.S.A., Knight of Vasa. 1893" and a printed auction listing "226. Colebrook (H.T.) Notice historique sure la vie et les ouvrages de M. Colebrooke par M. C.A. Walckenaer, Paris, 1848, with biographical notices from various periodicals and numerous interesting autograph letter of Colebrooke, half red calf". Frederick Hendricks is an ancestor of the donor who also has family connections with the Colebrooke family.