 In 1921 Douglas was appointed director of the Department of Bacteriology and Experimental Pathology in the National Institute for Medical Research under the direction of Sir Henry Dale at Mount Vernon Hospital in Hampstead and also deputy director for the NIMR under the director Dale.As head of his department, Douglas organised the research of Laidlaw, Dobell, William E. Gye (who worked on the Rous sarcoma virus), Ian A. Galloway (who worked on foot-and-mouth disease) and other researchers.Much of the research dealt with immunology and virology, especially viruses that cause dysentery.