Subseries consists of Sir William Dawson's letters from a range of correspondents including family members, scientific and university colleagues, business and tradespeople, and friends and acquaintances. Of the 3.2 m of Dawson's general correspondence (c.1-c.19) covering the years 1837-1899, about 5,000 letters are on scientific subjects. With the passage of time, and particularly from the late 1870s onwards, the character of the correspondence becomes less substantially scientific, and more administrative, institutional and formal; at the same time, there is a marked shift towards North American correspondents. Perennial topics are geological exploration, the exchange of mineral specimens, and research or theoretical problems, but these are eventually outweighed by the business of learned societies, government science policy, demands for Dawson to lecture or write, and reactions to his publications. In the 1880s, the Darwin and Eozoon controversies are especially prominent. In 1891, there is correspondence relating to the meeting in Montréal of the Royal Society of Canada. Dawson's correspondents include academics, officials of learned societies, and a number of prominent researchers. There are substantial numbers of letters from Sir Charles Lyell, J.J. Bigsby, Sir William Logan, Spencer Baird, James D. Dana, David Penhallow and J.S. Newberry. Drafts of some of Dawson's outgoing correspondence are included. Dawson's correspondence also contains some items, largely from the Nova Scotia years, on his involvement with church affairs, missions and tract societies. Some clergy, such as the Rector of Little Metis, where Dawson kept a summer house, are amongst his regular correspondents. In later years there are inquiries from the general public on matters of science and faith, and the occasional letter from a religious eccentric. Some items amongst his general correspondence also relate to his education career as the Superintendent of Education in Nova Scotia, as well as to his applications to the University of Edinburgh; most, however, stem from his years as Principal of McGill. These letters discuss educational legislation and the activities of the Protestant Committee of the Council of Public Instruction, consult on points of information and policy with other universities and inquire about McGill's programmes. Noteworthy are the draft letters to Chancellor James Ferrier on the administration of McGill during Dawson's absence in Europe and the Near East (1883-1884), and an exchange of letters with Daniel Wilson of the University of Toronto on the question of co-education. Dawson's 30 cm of family correspondence include letters from Margaret Mercer Dawson, 1842-1845 and later; his son, George Mercer Dawson, on geological and personal matters; and other family members, ca 1869-1899 (c.48-c.49). Finally, his financial affairs are illustrated by letters amongst his general correspondence concerning his mining interests in Nova Scotia, particularly with his agent Howard Primrose and his partner E.A. Prentice. The numerous invoices and receipts are largely for domestic expenses, but include the subscriptions for his lectures to the Natural History Society of Pictou (1849), and bills for the printing and distribution of Dawson's publications.