Douglas William Greig was the eldest son of J.H. Greig and his wife M. Greig, of Newcastle-on-Tyne, England. He was employed at the Modderfontein Dynamite Factory and as co-author of William Cullen* published a paper on "Analysis of gases from burning nitro-glycerine explosives" in the Journal of the Chemical, Metallurgical and Mining Society of South Africa (1909/10, Vol. 10, p. 90).
Greig was a member of the Modderfontein church choir. He died at Modderfontein, at the age of 26, and was buried there.