Kyaukpyu contains numerous "mud volcanoes," from which marsh gas is frequently discharged, with occasional issue of flame.
According to this theory a " chemical type " embraced compounds containing the same number of equivalents combined in a like manner and exhibiting similar properties; thus acetic and trichloracetic acids, aldehyde and chloral, marsh gas and chloroform are pairs of compounds referable to the same type.
Fire-damp and dust explosions are caused by the presence of marsh-gas in sufficient quantity to form an explosive mixture, or by a mixture of small percentages of marsh-gas and coal-dust, and in some cases by the presence of coal-dust alone in the air of the mine.
Explosive mixtures of marsh-gas and air may be fired by an unprotected light.
But when coal-dust is present, and little or no marsh-gas, an initial explosion - such as is produced by a blown-out shot - is required.