Collection consists of 36 autograph letters written to James Cameron and his son Archie. The correspondence includes letters by friends, associates, and members of the Cameron family in Toronto, Lake Beauport, Scotland, England, Hull, and Montreal. Subjects include family news, freemasonry, business (regarding deed of sales), factory work in Toronto, curling, and an April Fools' Day letter. With three extant envelopes.

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.

The collection contains private records and papers relating to the medical and teaching career of Maude Abbott. It consists in large part of correspondence, 1894-1920, including family correspondence with, among others, her sister Alice Abbott, 1904-1919, and her brother Rev. Harry M. Babin, 1916-1920. Also included are manuscripts and drafts of articles and addresses; case reports; post-mortem records; glass slides and drawings; exhibit panels largely pertaining to her research on congenital heart disease; programmes of medical meetings, 1902-1937; reprints and papers relating to the history of medicine in Montreal and Quebec, as well as to the history of McGill, 1829-1936. In addition, there are photographs, some poems, an autobiographical sketch and a printed copy of her Classified and Annotated Bibliography of Sir William Osler's Publications, 1939, with corrections and annotations by W. W. Francis. Fonds also includes a draft of Abbott's letter to the Dean of Faculty of Medicine, McGill University, regarding admission (1889).

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.

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.

The collection contains correspondence, curriculum vitae, a poem written by his wife, Elizabeth Turnor, a record of medical examinations for the Coroner's Court of Montreal, 1894 and lectures notes. The greater part of the notes consists of embryology notes made at the Anatomisches Institut, Munich, around 1900.