The fonds consists primarily of Logan's scientific work. A small percentage relates to the affairs of his family and to memorials to Logan after his death. The great majority of the papers consists of scientific correspondence from about 1820 to 1874, but mostly for the years following his appointment to the Survey in 1842. The letters deal with the collection, exchange and description of geological specimens, expeditions under the aegis of the survey, problems of research and scientific interpretation, scientific meetings, and visits by scientists. The number of correspondents, both individuals and learned societies, is very large, but the most substantial bodies of letters are from J.W. Dawson, geologist and Principal of McGill University, James Hall, paleontologist of the New York Geological Survey, Alexander Murray, Logan's chief assistant, and James Lowe of Grenville, Québec, who supplied Logan with specimens and appears to have been casually employed by him on surveying jobs and field trips. Other correspondents include Sanford Fleming, E.D. Ashe of the Québec Observatory, Thomas Sterry Hunt, and R.I. Murchison of the Geographical Society of Great Britain. Some letters pertain to political or social affairs, but usually in close connection with the scientific work of Logan or the Survey. These files contain copies of some of Logan's outgoing letters, as well as some letters addressed to other individuals, generally his assistants. Other scientific papers consist of field trip records (a journal kept during an expedition in 1845, a weather table kept on Lake Superior in the winter of 1846-1847, work records and astronomical readings for surveying projects, notes on mineral deposits, and lists of specimens), manuscripts of three scientific papers, as well as "Observations on the proposed Geological Survey", and manuscript and printed maps and geological schemata, including some by Logan of the Bay of Fundy, Labrador, and Hamilton, Ontario regions. Manuscript catalogues of specimens were prepared by Logan for the Paris Exhibitions of 1855 and 1867. Official reports include Logan's annual reports for 1842-1844, an overview of the work of the Geological Survey, 1866, two reports by Logan on prospects for mining on the north shore of Lake Superior, 1846, 1847, and one on mineral deposits around Rivière-du-Loup, 1853, as well as Logan's copy of his proposed Geological Survey Bill, 1844, and some copies of reports on mining and cartography prepared by others. Logan's financial records include expense accounts for Geological Survey expeditions, as well as other professional expenditures, such as books. His private and family life is reflected by a very brief diary of an Atlantic crossing in 1856, letters to and from his brothers James and Henry, his father, his uncle Hart Logan, and Hart Logan's partner John Fleming, covering the years 1772-1856. There are also baptismal and burial certificates, and legal documents, particularly bills of sale pertaining to James Logan's farm. Memorials to Logan after his death include J.W. Dawson's correspondence concerning the Logan Memorial Fund and Collection, 1881, and a manuscript biography by Alexander Murray. There is a chronological and author/recipient index to these papers.

Additional materials received from McGill Library's Rare Books and Special Collections consist of correspondence, 1837-1871; notices of admission to scientific and historical societies, 1842-1867; a history of the geological survey 1850; a report on mining locations addressed to B. Papineau, 1847; and correspondence with Robert Bell, 1861-1874.

The fonds contains professional and private correspondence from Emma Albani, the first Canadian-born singer of international fame, to Parisian publisher Henri Heugel.

Collection consists of 38 letters written primarily by John Wood Senior to family members in England. Many of these were written to a sister or sister-in-law and a few are addressed to his brother, Will Wood, a watchmaker and jeweller in London, including two in which Wood includes a list of trade supplies to order. Four letters are from John Wood's son, Peter Wentworth Wood. One letter is by John's wife, Anna. Contents include topics such as the country's economy, Canadian-British politics, the Woods' watchmaking and jewellery business, crops, slavery, and the American Civil War, as well as local Montreal news on subjects such as fires, the Victoria Bridge, a cholera outbreak, the 1856 Railroad Celebration, and a visit by the Prince of Wales. Letters also include family news, particularly of John Wood's children Peter, John, and Charles, seafaring disasters, gold mines, improvements in shipping in the St. Lawrence seaway and the Atlantic Ocean, the expansion of railroads, and the Atlantic Telegraph. Letters date between 25 November 1839 and 13 December 1867. One is a crossed letter.

McDonald's correspondence, 1791-1860, mostly concerns business and property matters, but also includes personal correspondence. There are statements of account with McTavish, Frobisher & Co., 1799; with McTavish, Fraser & Co., 1803-1804; with McTavish, McGillivray & Co., 1808-1809. There are two volumes of autobiographical notes assembled in 1859 and covering the period 1791-1816.

There is a second copy of the autobiography, probably transcribed in the late 19th century. Written on the front fly leaf is the name: A.E. MacDonald. It has 63 leaves, and there are minor textual variants.

Gould's papers fall into two series. Family correspondence covers the years 1856 to 1860, when Joseph and his brother Charles were travelling in Europe, and consists of letters home from both young men, and their parents' replies. Manuscript music comprises two volumes of church anthems, with some organ music; some are original compositions by Gould and Samuel Warren. Related to this is Gould's brief manuscript account of the origin of the Mendelssohn Choir. Some family photographs are also included.

Fonds consists of letters written to P.M. Roget by various people, 1830-1856.

Fonds consists of autographed signed letter from Workman to John Auld of Montreal on Workman’s engraved stationery (Matthews lithographer), 25 November 1852.

This collection consists of 15 autograph letters between a sender who is only identified by the initials "J.T." and a Miss Fanny Caulfield. Also included is a love letter by Irish poet J. Finnerty, dated 1852.

Fonds consists primarily of correspondence between Hertel de Rouville and members of the Canadian government, including Chief Secretary of Lower Canada Sir Thomas William Clinton Murdoch (1809-1891) and Governors General Lord Gosford and Charles Bagot, regarding financial losses he incurred during the rebellions of 1837, 1838, and 1839, and half-pay claims dating from his time as captain of the Canadian Voltigeurs during the War of 1812. Also included are five envelopes with wax seals intact.

Fonds consists of six autograph signed letters written at Montreal by Ann Adams, dated between 24 March 1834 to 26 December 1937, to her son Edward H. in Providence, Rhode Island, and Philadelphia. Letters contain local news (churches and organs built, the railroad to St. Johns, fires, printing and publishing, cholera, etc.), observations on the worsening tensions between Papineau and the "Canadiens" and the "Loyalists," and accounts of preaching by an Indigenous convert to Christianity.