The project files which occupy most of the archives of J.T. Donald and Co. fall into two series: ordinary business and special assignments. Both series contain the firms report's, and correspondence. Special assignments were largely connected with wartime armaments production. A few files concern work for the Imperial Munitions Board in World War I, but most consist of reports for the Chemical and Explosives Branch of the Department of Munitions and Supply, 1939-1948. Ordinary projects involve consultation for food, pulp and paper, petroleum, and chemical manufacturies, as well as for some government departments, 1888-1940. Outgoing correspondence from 1881 to 1909 is contained in letterbooks. A file of legal documents, 1924-1946, refer to claims against the company, agreements, and partnerships. Also included are an undated notebook on chemical analysis, and scrapbooks and files of newsclippings of professional interest (e.g. reports of explosions caused by oil and gas) covering the period 1916-1958. There are also reports on mining and energy sources prepared by Donald alone and also in partnership with J.H. Ross for various private and government bodies.