the heat being not of the same kind, but quick and fierce, tending not to nourish but to consume and dissipate all those noxious fumes which the other kind of heat rather exhaled and stagnated than separated and burnt up. Besides, it was alleged that the sulphurous and nitrous particles that are often found to be in the coal, with that bituminous substance which burns, are all assisting to clear and purge the air, and render it wholesome and safe to breathe
