Letter from Henry Thomas Colebrooke to Nathaniel Wallich in which he gives advice on when to send plants as the current specimens were all dead when he retrieved them from the Custom House. He writes of jealousy among the Directors of India House if plants arrive for private persons and so therefore asks Wallich to send specimens to them but to continue to send him seeds. He adds thanks for geological specimens and for Wallich to forward letters of acknowledgement to General Hardwick and Dr Adams. He asks whether the other gentlemen might be interested in joining the Geological Society. Handwritten, dated 20 January 1820, received 9 July 1820.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich in which he thanks Wallich for Nepal seeds and for rock specimens sent to him. He gives details of how various seeds and plants are growing in England mentioning Sir Joseph Banks and Mr Lambert. Wallich has been elected to the Linnaean and Geological Societies. Colebrooke will pay his fees if Wallich will reimburse to Colebrooke's agent. Colebrooke thanks for interesting papers that Wallich has sent including Captain Webb's account concerning the Himalayan mountains. Handwritten, dated 22 April 1819, dated in Wallich's hand, received 8 October.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich in which Colebrooke discusses the periodicals that are being sent and how much the remittance will cover. He writes that he has just learnt, with regret of the death of Dr Jack. Handwritten, dated 8 January 1823, received 17 June, 1823.

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]

Letter from Henry Thomas Colebrooke to Nathaniel Wallich concerning publications that Colebrooke will forward to Wallich. He reiterates his request to send specimens direct to the Geological Society because of the cost incurred at the Custom House. Handwritten, dated 12 March 1821, received 30 August 1821.

"Extracts of three letters from Mr. H. Colebrooke to Dr. W. Carey". These concern the appointment of Dr Wallich at the Botanic Gardens and are dated 6th January, 13 January and 26 January, 1817. At first Colebrooke would not recommend Wallich because he thought another eminent botanist had been appointed but on discovering that this botanist had no wish to travel to India, Colebrooke and Dr Fleming petitioned the Court of Directors, East India Company, with the support of Sir Joseph Banks, for Wallich to be appointed to the role. Handwritten, copied by unknown hand.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich to ask Wallich whether he would like the earlier volumes of the Geological Transactions to complete his set as they are available at modest terms. Colebrooke and Mr Lambert have had an interview to request an assistant for Wallich but, as yet, do not know the outcome. The specimens that Wallich sent are still undistributed and therefore Colebrooke suggests that Wallich apportions them to men of science in future. In a postscript Colebrooke mentions that Richardson is still sending publications to Wallich. Handwritten, dated 30 March 1824, received 29 September 1824.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich from Cape of Good Hope. Colebrooke has been more concerned with matters to do with his landed property than with botanical matters but has gathered some geological specimens. He requests that Wallich send seeds to the Cape to James Gosling, that he thinks might be profitable for the region. Handwritten, dated 12 March 1822.