The fonds consists of manuscript travel journals, engravings, and letters of naturalist, artist, and author James Forbes. The fonds containsa five-volume fair copy of a manuscript travel journal prepared by Forbes describing his travels and stays in Germany, Italy, and Switzerland during 1796 and 1797. Entries describe the climates, cultures, art, monuments, and historical sites of the places he visited. Some entries also reflect current events, such as the French Revolution, and comparison between the places he visited and his native England. The journals were prepared by Forbes ostensibly for his daughter, to whom the first volume contains a dedication. The fifth volume contains an addendum dated 1799. The The fonds also contains two letters, one a letter to Forbes from his grandson, the Count of Montalembert, and one a letter from Forbes to his sister, Eliza Fothergill, dated 1788. The final materials in the fonds are two hand-coloured engravings of illustrations created by Forbes in 1771 and 1783, and published by Richard Bentley (London, 1834).

Collection consists of 57 illustrations of birds, eggs, snakes, and plants by James Forbes chiefly to illustrate his work "Oriental Memoirs," published in four volumes between 1813 and 1815. The majority of the illustrations are either engraved or hand-drawn and then coloured, and have been cut out and mounted on paper. In many cases, a background has been drawn in and coloured or partially coloured. Approximately thirty of the images depict tropical birds, many from the Indian subcontinent, as well as some from Brazil and Australia. A number of these drawings also feature insects, particularly butterflies, and trees and flowers. Fifteen drawings depict bird eggs, including many of forest birds. The images generally contain captions by Forbes or a contemporary, identifying the subject of the drawing. Some birds are unidentified. Numerous drawings also contain species identifications or annotations in pencil by Henry Mousely, librarian of the Blacker Wood Library at McGill University during the 1920s and 1930s. These drawings are tentatively dated to approximately 1811. A note on one drawing indicates that it was originally based on drawings created during Forbes's voyages during the 1780s, then recopied in 1811. Items 44 through 57 depict snakes and reptiles and are tentatively dated to between approximately 1811 and 1818, based on a small number of drawings which are signed and dated. Many of these drawings of snakes and reptiles feature as plates in Patrick Russell's "A Continuation of an Account of Indian Serpents: Containing Descriptions and Figures, from Specimens and Drawings" (1801).