Consists of an English translation of a letter to the Marquis de la Jonquière written by Antoine-Louis Rouillé, comte de Jouy, secretary of state for the French Navy, at Versailles, dated 28 February 1750. The letter discusses an immediate release of prisoners of war taken during conflicts between the French and British colonies. It also includes a mention of Indigenous allies of England and France, and Indigenous people captured during the conflicts: "the Indian Prisoners among the two Nations be likewise released, but after all the French and English Prisoners are released" The letter also includes the name of examiner Josiah Willard, secretary of the province of Massachusetts-Bay.

The collection consists of autographed signed letters from multiple senders, representing authors, artists, politicians, and other figures from Canada and Europe. The letters were accumulated by the Rare Books and Special Collections unit of the McGill Library over many years and assembled into the collection.

This collection consists of translations from Terence, begun in 1778, and correspondence on military, political and private matters, 1787-1821, mostly addressed to Thomas Coutts, banker.

Frobisher's papers comprise a letterbook of the North-West Co. containing copies of letters written by Frobisher from April 1787 to October 1788, two original letters to Simon McTavish, 1796, and one from him, 1787, business and legal documents, largely concerning the estate of James McGill, 1810-1834, and a diary, 1806-1810, mostly a record of where he dined.

There is business correspondence, 1792-1800, with letters from among others Alexander Mackenzie, Joseph Frobisher, Alexander Henry, Simon Fraser and Roderick Mackenzie. There are also minutes and resolutions of the Executors of McTavish in a bound volume; and a contemporary copy of the minutes of the executors of his will, 1805.

The Sir William Osler Collection, distinct from the Bibliotheca, is an extensive archival holding of Osler's correspondence (including eighteen hundred original letters), daybooks, accounts, engagement books, legal documents, book invoices, membership certificates, notebooks, lectures, addresses, newspaper clippings, photographs, books with manuscript additions, and miscellaneous loose items formerly inserted into individual books in his library. The collection also contains various family papers, including correspondence of Lady Grace Revere Osler and Edward Revere Osler.

The collection consists primarily of correspondence on natural history topics between scientists and natural historians. Letters are sometimes accompanied by journal articles.

Figures with significant correspondence within the collection include: Casey Albert Wood, Henry Mousley, Robert Ridgway, and Bowdler Sharpe.

This collection consists of contemporary copies of letters written by T. Blackwood from Michilimackinac to James and Andrew McGill & Co., to Ch. Chaboillez, and to T. and J. McGregor.

Collection of correspondence between the years 1818 and 1828, predominantly on the matters of The Society of Antiquaries of London, addressed to Daniel Lysons, a British antiquarian and topographer. Comprises 25 letters mounted on paper. The first letter of September 5, 1818, is addressed to Samuel Lysons (1763-1818).

This collection reflects Henry S. Chapman's relationships with a number of important figures in Montreal's political and business history, between roughly 1833 and 1853, the period following Chapman's return to London. A significant amount of the material in this collection is related to the 1837-1838 Upper and Lower Canada Rebellions (especially in Montreal), as well as events occurring immediately after the uprisings.

Consists of copies of original material, chiefly correspondence, arranged roughly by date. The contents of letters (1835-1853) include business partnerships, political reform, and personal news. Significant correspondents include Louis-Joseph Papineau, Louis-Hippolyte La Fontaine, Jacob Dewitt, François-Antoine Larocque (of Laroque and Bernard), Joseph Perreault, and Edmund Bailey O’Callaghan. There is also a partial manuscript on Canadian history and pages from a scrapbook, both dating from the 1830s.