Note:  Do not rely on this information. It is very old.

Choke Damp

Choke Damp, the name given to the carbonic acid gas which is found accumulated in coal-pits, wells, etc. After explosion of fire-damp (CH4) in coal-mines large quantities of this gas are formed, and it is also called "after-damp." It does not support life, and frequently in colliery explosions more deaths are attributable to it than to the explosion itself.