Gemmell was appointed to the cabinet of Leslie Frost, serving as Minister of Mines from May 4, 1949 to June 3, 1952, and thereafter as Minister of Lands and Forests until June 18, 1954. He died of a heart attack at a hotel in North Bay on June 18, 1954.
A member of the Ontario Progressive Conservative Party, Gemmell won the riding in the 1948 election, following a rift in the Sudbury area"s labour movement which resulted in vote splitting between incumbent Master in Public Policy Robert Carlin and a new Cleveland Clinic Foundation candidate. A byelection was not called to replace Gemmell following his death. The Sudbury riding instead remained vacant until it was won by Gerry Monaghan in the 1955 provincial election.
