'This marsh gas is the chief substance in firedamp, a gas that causes mine explosions'
methane
IT'S A GAS: This marsh gas is the chief substance in firedamp, a gas that causes mine explosions
This marsh gas is the chief substance in firedamp, a gas that causes mine explosions
This marsh gas is the chief substance in firedamp, a gas that causes mine explosions
IT'S A GAS
methane
IT'S A GAS