The air is another storehouse of fire. When lucid igneous particles are strongly attracted to one another in great quantities, their heat becomes intolerable, and is capable of destroying the most solid bodies. It is well known, that when converged in the focus of one of Hartsocker’s burning-glasses, they will produce wonderful effects: tin, lead, or any soft metal, will dissolve at the first touch; and iron, which requires a very strong fire for liquefaction, will melt before one of these glasses almost as soon as applied. They will consume wood, though wet, in a moment; vitrify bricks and pumice stones, and dissolve earthen vessels full of water; and plume-allum, which will resist the fire of the hottest glass-houses, without alteration, is instantly melted. Even gold, that resists the force of common fire, is soon liquefied by their powerful agency. This plainly shows us that, provided there were not a wise and almighty Providence, superintending all his works, those materials which are of the greatest utility to the harmony and order of things, would have a direct tendency to destroy the whole. If lucid igneous particles were to form solid bodies, and depart from their state of fluidity, they would, in an instant, reduce this globe to ashes, or render it liquid fire. Were they all of one kind, it is probable they might unite in solid bodies; but the wisdom of Providence has formed them of various colors, and of different reflections and refrangibility. This prevents them from associating in such a manner as to do harm, which can only be produced by converging them with some instrument which prevents their flying off. As all these have not the same degree of reflexibility and refrangibility, but as some are capable of greater reflections and refractions than others, they cannot, without force, be united in one solid body, yet they are all serviceable for important purposes, contributing to the happiness of man, and the welfare of all living creatures.