The ease with which the largest gas-light flame is instantly extinguished by shutting the stop-cock, and the readiness with which a long line of gas catches fire by applying a lighted taper to one extremity, are properties that cannot fail to recommend it for the purposes of telegraphic communications by night. Another application of the gas unquestionably might be the lighting of barracks, arsenals, dock-yards, and other establishments where much light is wanted in a small place. The annual expence of lighting the barracks of Great Britain is said to fall little short of 50,000l. a small part of which on the new plan, would supply them with a much purer and safer light. The uses of the gas-lights already enumerated must of themselves, justify us in attaching great importance to the discovery, and if reduced to practice all over the kingdom, would employ a large capital in a way the most advantageous and productive. But the utility of this light will be almost indefinitely increased to the use of private families. That such an application is practicable, in all towns of Great Britain, is obvious, from what has been done already, and that it would be highly economical and ornamental, there can be little doubt. By means of gas we may have a pure and agreeable light at command in every room of our house, just as we have the command of water, with this singular advantage, that these lights may burn for hours within an inch of the most combustible substance without danger, because they neither can burn down like a candle nor emit sparks. These properties make the gas-lights a most desirable light on board our ships of war, where severe regulations are necessary to prevent danger from fire, which after all are frequently evaded. The gas-light might be used in the store-rooms, and even in the powder magazine, and the captain would completely command the supply of light by the possession of the key which opens and shuts the stop-cock. A small apparatus which may be erected at a trifling expence would be sufficient for that purpose. In shops, counting-houses, and public offices, the advantages are a white light, nearly equal to day-light, a warmth which almost supersedes the use of fires, a total absence of smoke, smell, and vapour, and great economy of labour. The heat produced by gas-lights must be observed by every one who has had an opportunity of attending to it in the most superficial manner, and the reason why gas-lights produce more heat than oil or candle-light will not appear strange to our chemical readers (and who is there now that does not know something of chemistry?) when it is considered that the gas-light flame condenses more air than the flame of oil and tallow, and consequently must produce more heat. The flame of gas may be produced in so large a surface, as to be applied to heat the most spacious apartments as well as to light them.