The substantial catalogues series covers most of the inventory of both the Society’s museum and library. Museum catalogues provide detailed information regarding the genus, species and origin of their Mammalia Collection while catalogues of donations to the museum also point to interesting objects in their collection. Library catalogues list publications in the Society’s holdings. The series also provides important lists related to the Journals of Assembly and to the visitors of the museum.

This series contains of Cushing's typewritten drafts of chapters from his book, The Life of Sir William Osler. The series is arranged into files corresponding to chapter divisions.

The series consists of chiefly of letters written by Osler that Cushing collecting during the preparation of his biography, The Life of Sir William Osler, between the years of 1920 and 1924. The letters in the series include both originals and transcriptions. The series also contains accompanying notes (both by Cushing and by Osler), clippings, articles, and other ephemera related to Osler.

The minutes series comprises eight bound volumes, two publications and one envelope of loose duplicate minutes. The minutes document proceedings from the annual, general, monthly, special, ordinary and extraordinary meetings held by the Society. It consists of the minutes from the Natural History Society (1827-1923), the Natural History Society Council (1827-1922), and the Natural History Society Committees (1906-1908).

The handwritten and typed minutes document the Society’s activities, including lists of members, newspaper articles, donations to the Society, elections, advertisements for sponsored lectures, and reports from committees. Handwritten copies of letters from Dr. Meade, Mr. C.U. Shepard, Major Delafield (File 5.2) and Robert Burn (File 9.1) to the Society as well as letters sent on behalf of the Society (Smithsonian Institute, File 5.1) are included with the minutes.

Included are watercolours and drawings of Egypt and India as well as details and sketches of churches in England and Italy.

The Studies & Analyses Series contains Schloss’s academic work from his studies at the Hoch Conservatory in Frankfurt and under Alban Berg, as well as his analyses of works by other composers. Listed items are grouped by genre: academic studies, analyses of works by other composers, studies of unknown works, transcriptions of melodies, and sketches.

Series consists chiefly of letters between Maude Abbott and her sisters, as well as other personal correspondence. One correspondent represented in the series is Dr. C. F. Martin, a McGill physician who was a friend and advisor to Abbott. Other correspondemts include Lady Osler, Archibald Malloch, Walter Chipman, Thomas McCrae, and Lady Drummond. Two letters exist from W. W. F. Francis. Two letters related to the No. 3 Canadian General Hospital (with correspondents H. S. Birkett and Edward Archibald).

Series documents the administrative and financial activities of the UCM from 1901-1919. Chronological files include a constitution, meeting minutes, correspondences, memorandums, convention publications, circulars, cheques and invoices, and financial reports. The series is organized and arranged chronologically, with each file contains records documenting the activities of the UCM of a particular year.

Series consists of 5 drug formularies estimated to contain approximately 1200-1300 formulas. Notebooks also contain financial data (half-yearly summaries) for approximately 12 years dated between 1896 and 1914, of great significance for quantifying the size of the business and its inventory value (see also File no. 19 for additional financial data).