Letter from Henry Thomas Colebrooke to Nathaniel Wallich in which Colebrooke thanks Wallich for his reports on timber forests. He is pleased that Wallich continues to send specimens to India House and distribution is now less of a problem. He thanks Wallich for seeds which he has given to Mr Lambert. He also wishes to express his thanks to Wallich and Mr Hodgson for their present to the Royal Asiatic Society which when it arrives will be presented. He also asks whether Mr Hodgson would like to be proposed as a member of the Royal Asiatic Society. He discusses bills that Wallich has sent and closes with the news that Wallich's Lady is in town and Colebrooke hopes to call on her soon. Handwritten, dated 30 May 1826, received 17 January 1827.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich concerning Wallich's concern on sending specimens to India House and publications to be sent to Wallich from Richardson. There is a postscript in which Colebrooke reports that Law desires to be remembered to Wallich, that the plants have been given to the Horticultural Society and the seeds given to the Court of Directors to distribute among their friends, However, generally, Indian seeds do not germinate in England. Handwritten, dated 6 November 1823, received 31 May 1824.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich in which he discusses the possibility of the introduction of rice to England. Colebrooke thanks for letters, boxes of specimens and anthropological drawings. Colebrooke asks Wallich to express his thanks to the gentlemen that provided geological specimens. Colebrooke has petitioned the Chair of the Court of Directors, East India Company on Wallich's behalf. He wishes Wallich a speedy recovery to health. Handwritten, dated 8 August 1820, received 25 February 1821.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich asking for him to supply botanical information in order for him to complete a publication on Indian plants. The letter includes a list of the information that he needs. He also asks for information about certain teak plantations. Handwritten, dated April 1817 from Albany London, with mention of Lord Castlereagh, 4 September in Wallich's hand (Boat on which the letter arrived).

Letter from Henry Thomas Colebrooke to "My dear Lord". Acting in his role of President of the Asiatick Society (role held from 1806--1815) he was requesting that the Lord, as Patron, would act to enable Dr Wallich, keeper of the Society's museum to continue at the Presidency rather than be sent to his recent appointment at an outstation. Handwritten, dated 19 October 1814 from Calcutta. Appended to this letter is a copy of a note written by Wallich about his debt to Colebrooke in obtaining his position at the Calcutta Garden. Handwritten, dated 15 October [1820]. This has further handwritten annotation stating that "The following... Extract from letter of Dr Wallich to Dawson Turner and is in the handwriting of the latter."