262 Proposal fur Sestroying 



munity. It is written in a popular mannet, and, we think, 

 deserves the attention of those to whom it is addressed. 



The decomposition of water when carloniuxons matter, 

 or coaly comes in contact with it, and the affinity which 

 the oxygen of the water has for carhon, account satisfac- 

 torily for the formation both of fire-dumf) (hydrogen gas) 

 and of ckoak-damp (carbonic acid gas) . The hydrogenous 

 gas, from its specih'c gravity being so much less than that 

 of atmospheric air, as 13 to 1, or \Q to 1, if perfectly pure, 

 ascends to the roof of the mine: the carbonic acid gas, owing 

 to its specific graviiv being more than twice that of common 

 air, falls to the bottom. When these two do not by their 

 bulk (ill the space between the floor and top of the n)ine, 

 a stratum of atmospheric air lies between them, being nei- 

 ther so heavy as the choak-domp nor so light as the fire- 

 damp. Neither the hydrogen nor carbonic acid gas arc 

 respirable, if unmixed with atmospheric air; and wherever 

 the former takes fire it must be in contact ar mixture with 

 atmospheric air, as it cannot be inflamed without ii : — the 

 result of the combustion is the formation of water which 

 consists of hydrogen O'lo and of oxygen 0"S5 ; and thus 

 pit-men who liave been scorched with the explosion of fire- 

 damp appear as if drenched with water. — Such, briefly, 

 are the facts brought to view by the author, Dr. Trotter. 



Dr. Trotter, in prosecuting his object, points out, 

 1st, The means to prevent the formation of noxious airs 

 in the mines : 2d, For removing them when formed. 



For the first, the mines should be as well ventilated as 

 possible by the usual means : but one great object ought to 

 be to prevent all sta;:nation of water ; for where there is no 

 moisture there can be no generation of the foul airs. Wliere- 

 eyer water can stagnate, a stream of pare water should be 

 admitted at intervals to dilute ar^d sweeten it, that the whole 

 mav be pumped out ; and no chips of wood, or horse dung, 

 should be allowed to mix with the water that may become 

 ?ta'i;nate. 



To destroy fire-damp " we have only to employ some 

 of the stronger acids in a state of vapour, such as the acetic, 

 nitrous, or oxygenated muriatic. These acid vapours seize 

 the hydrogen. In the expansible stale of the acid gas its 

 oxygen quits the radical or base of the acid and attracts the 

 hydrogen; wau r is rccomposed, but the caloric disengaged 

 during the combination of the oxygen and hydrogen con- 

 verts it into steam, so that it is not seen inacondcnsed state. 

 This is the w hole secret of destroying hydrogenous gas, 

 or fire-damp." The oxygenated muriatic acid gas, on ac- 



CQlUlt 



