The bulk of Girdwood's papers concern his work in forensic medicine. Other materials cover his research in photography, and his general medical and scientific interests. Girdwood's career as medical-legal consultant is documented by 24 cm of his notes and reports, together with some correspondence, on four poisoning trials: People vs Emma Davis (Malone, N.Y., 1881), Queen vs Provencher and Boisclair (Sorel, 1867), Queen vs Joseph Ruel (St. Hyacinthe, 1868), and Queen vs David Prevost and Damase Brunet (L'Orignal, 1881). There are also coroner's autopsy reports and notes for four cases; Girdwood's memoires of ten cases on which he served as consultant; Rogers and Girdwood's submission to the Home Office, London, on the strychnine test, together with letters to Lancet and the Times on the same subject; and notes on the counterfeiting of stamps (1893). His interest in medical photography is reflected in lists of X-rays taken by him (1898-1899) and reprints of three articles. His general scientific and medical activities are represented by a scrapbook of newsclippings on cholera (1854), a lecture on gold presented to the Natural History Society of Montréal (n.d.), essays on strychnine (1864) and water filtration (1869), a review of a textbook in physiology (1864) and some reprints, including convocation addresses to the Medical Faculty. Finally, there is a manuscript copy of an address to the graduating class of Applied Science in 1881 and a small scrapbook of printed articles by Girdwood's father, G.F. Girdwood, M.D.