The fonds contains correspondence related to the Osler Library and its holdings with people such as Maude Abbott, Edward Archibald, William B. Bean, Edward Horton Bensley, Archibald Malloch, Casey Wood, as well as John Farquhar Fulton, Keeper of the Medical History Collections at Yale University's library; the fonds also contains a typescript of talks by W.W. Francis (titled "Showman's Patter") about books and other items held in the Osler Library.

The Alice Johannsen fonds reflects her lifelong involvement in nature, museums, community and her fealty towards her father, Herman-Smith (Jackrabbit) Johannsen. It consists of three series; personal and family series, 1994 to 1991, the Redpath series, 1919-1971 and a professional activities series, 1919-1971.

The fonds includes Dr. Archibald’s correspondence and reports pertaining to the Ministry of National Defence, 1940-1945; certificates and diplomas; and a photograph. The correspondents include family members, Dr. John McCrae and Sir William Osler. There is also a draft of a book on wound ballistics and gas gangrene; an Army Field Service book, 1916 and two notebooks on internal and external pathology, “matiere medicale et therapeutique,” and “medecine legale et toxicologie,” 1895.

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.

Fonds documents Burton Chance's links with Casey A. Wood from 1922 until Wood's death in 1942. The fonds contains correspondence between the two men, reprints of C.A. Wood and letters from various correspondents concerning C.A. Wood.

Fonds contains correspondence mostly between George Dock and Sir William Osler but also with Lady Osler, W.W. Francis and Archibald Malloch, from 1891 to 1919. The fonds includes 106 letters, originals and carbon copies.

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.

Fonds consists of records (originals, printed materials, photographs and motion pictures) that are almost entirely of a professional and research nature, covering Barnes’ general scientific and university work during World War I, a number of special research problems, and his involvement in scientific and social organizations.

His general scientific and university files (1914-1915) contain correspondence, including copies of some of Barnes' outgoing letters on departmental adminstration, Barnes' lectures, publications, scientific apparatus, research problems and the exchange of information. Correspondents include colleagues in other institutions (including Ernest Rutherford), learned societies, and private industry. This series also contains a file on purchases for the University Library, and inventories of Barnes' library.

Far more extensive are the materials on special research problems. These comprise notes, essays and correspondence on the detection of submarines (1915-1917) and on the development of anti-freezing devices for fire extinguisher and sprinkler systems (1917). A report by Barnes on the effect of ice conditions on St. Lawrence navigaton is supplemented by printed background materials and copies, or extracts from other reports. Barnes' work on icebergs is documented by five binders of clippings, photographs, maps and diary notes on research expeditions to Newfoundland (1924-1929). Practical experiments in ice clearance are illustrated by bound notebooks of clippings and photographs, as well as a number of loose photographs showing ice and flooding damage, use of thermite and calcium chloride, apparatus and ice-crushers (ca 1921- 1929). Finally, two reels of 35 mm motion picture film (ca 1930) show Barnes experimenting with a new mercury microthermometer.

Barnes' work as Hon. Secretary of the Canadian Committee of the British Science Guild is documented by correspondence from 1907 to 1919, largely concerning the recruitment of members and officers, but also touching on a survey of science teaching in schools and the Panama-Pacific Exposition of 1917. Less extensive files cover Barnes' involvement in the International Council for the Exploration of the Sea (1912-1914), the Rotary Club (1917) and the McGill Graduates' Society (1919)

Fonds consists of general professional correspondence, 1913-1961, including Maass’ outgoing letters for 1946-1954. Topics covered include defence research, the Pulp and Paper Institute, N.R.C. appointments, visits of scientists, and political questions (e.g. letters to and from Lester Pearson on NATO and the nuclear deterrant). There are also letters of recommendation by Maass, and personal communications from colleagues. A special binder of congratulatory letters marks his election to the Royal Society (1940), and there are similar files on his retirement (1955), and of condolences to his widow at his death (1961). Maass also assembled photostat copies of letters by eminent 19th century British scientists addressed to his great uncle, Prof. Plucker of Bonn.

Studies and research are documented by a physics laboratory notebook (1908-1909), and a "summary of data on hydrogen peroxide" collected in collaboration with W. Hatcher (1918-1919). A few addresses on the Canadian Institute of Chemistry (1939), the Pulp and Paper Research Institute (1945), and the relation between the Defence Research Board and the universities are included.