The collection of James Humphreys contains company reports, notices to shareholders, articles in mining journals, press clippings, correspondence and photographs relating to the mining of gold, coal, metals, minerals and precious jewels in South Africa, Bechuanaland, Nyasaland, Rhodesia and East Africa.

Subject matter includes metallurgy, geology, mineralogy, mining law and legislation, labour and the recruiting of Black labour, mining history, personalities and Rand Pioneers and mining groups, covering the years 1926-1967.