The collection consists of two series:

Hodgson used much of his time in both Nepal and Darjeeling in research, wanting to discover and understand about the architecture, languages, ethnography, religion, zoology and botany. He collected specimens and manuscripts, and had many drawings made, which he donated to many collections throughout Europe. He was also politically involved during his Residency in Nepal, and also later in England, when he continued to show an active interest in the Indian subcontinent, particularly regarding trade and vernacular education. These Personal Papers reflect these interests and are a record of much of his activity - Hodgson and his wives seemed to have a need to record all his successes. He was also a keen annotator of material, so that most of the printed material also bears his handwritten comments.

Letter from Joseph Hooker to Brian Houghton Hodgson. He apologises for the paper he is using as all his writing paper has been used up on the accompanying journal which will explain to Hodgson what he has been doing. He writes of his surprise at the geology of the Himalayas and that he has collected rhododendrons and seeds for his father. He is thinking of staying a day or two at Pemiongchi. He writes about [Chamamaya] being a splendid fellow. There is a list of his food requirements and he asks Hodgson to send [Burchess] and Co. if he thinks appropriate. Handwritten, 1 piece, undated [1848-1850].

Letter from Joseph Hooker to Brian Houghton Hodgson. He writes that he had last written to Hodgson on his way to meet the Rajah. They have left [bamsong] after Christmas after a final interview with the Dewan who had been extremely attentive. The Rajah had told Archibald Campbell that Hooker could start for [Lachen] in spring. Hooker had informed the Dewan that he was certainly going. Hooker does not foresee much difficulty, Campbell having given the Dewan a warning. Hooker writes that Campbell had insisted on one who speaks Hindustani and the only one was the heir apparent's servant. Hooker continues to report on the negotiations between Campbell and the Rajah. He then talks about the geology and vegetation of the area he is travelling through. With accompanying envelope. Handwritten, 4 sides, dated 28 December 1848.

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 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 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 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 in which he describes the measures that he has taken to obtain an assistant for Wallich. He regrets the delay in Wallich receiving his publications. He remarks on geological specimens and asks Wallich to thank Capt. G. for the vocabulary of the Kunawar language and is unsure whether to deposit it in the Company's Library or that of the Royal Asiatic Society. He discusses his forestry plantations and the possibility of Wallich obtaining leave. He appends a memo concerning geological specimens. Handwritten, dated 27 July 1825, received 10 December 1825.

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.