'Choke Damp', c 1928.

Oil painting by Gilbert Daykin showing two miners coming across of one of their colleagues who has collapsed, unconscious or possibly dead. Choke damp is a suffocating gas, primarily carbon dioxide and Nitrogen, pockets of which occur in mines and could overwhelm miners. In the 19th century it was known as 'Black Damp' because it extinguished safety lamps. Daykin (1886-1939), a miner himself, was killed in a mining accident.