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 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 acknowledging letters sent and stating that he has sorted Wallich's remittances and arranged for the periodicals he requests to be sent to him. He was pleased with the geological specimens sent to him, including gold from Tartary and specimens from Lieutenant Gerard and Mr Scott and Colebrooke has used the notes sent by Gerard to write a paper on the geology of the valley of the Sutlej. He has proposed Lt Gerard and Dr Jack as members of the Geological Society. He thanks Wallich for seeds sent but advises because of the cost to be careful in thinking through which to send. Handwritten, dated 9 January 1821, received 5 June 1821.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich in which he writes concerning the high cost of importing specimens. He therefore asks that they are no longer sent to him individually but to send seeds to other sources who have requested them and geological specimens direct to the Geological Society. Mr Scott, Dr Jack and Lt Gerard have all been made members of the Geological Society. Handwritten, dated 22 February 1821, received 14 July 1821.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich concerning the Botanic Library. The East India Company Court of Directors have agrees £200 annually for 10 years for the purchase of books old and new. Thus he will ask Richardson to send certain publications at Colebrooke's discretion until he hears from Wallich. He writes of the cost of certain books that he has already sent and discusses other possible volumes. Handwritten, dated 22 September 1821, received 21 March 1822.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich in which he confirms the remittance for the Botanic Library by the East India Company Court of Directors. Colebrooke is on board boat headed for the Cape where he will stay a short time before returning to Europe. Dated 18 December 1821, received 24 March 1822.

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.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich regarding providing an annual supply of seeds for his plantations in the Cape. He lists varieties that he would particularly like Wallich to send and asks that they be directed to James Gosling Esq., at the Cape of Good Hope. Handwritten from Cape Town, dated 10 April 1822.

Letter from Henry Thomas Colebrooke to Nathaniel Wallich in which he congratulates Wallich for his success in research in Nepal. Colebrooke discusses publications to send to Wallich. He again reiterates the need to send specimens directly to such institutions as the Linnaean and Geological Societies rather than to him personally. Handwritten, dated 31 July 1822, received 1 February 1823.

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.