We concluded a previous notice of some of the uses to which water is subservient in nature, by mentioning that modern science had fully proved the incorrectness of the ancient idea of the elementary nature of water; and that by the processes which chemistry places at our disposal, we are now able to resolve water into its elements, or, having obtained these elements from other sources, to cause them to unite, and to produce water in combining. In the present article we shall point out the manner in which this may be accomplished, and describe some properties and uses of water which the space at our disposal did not allow us to notice before. Water consists in great part of the substance to which is due the power the atmosphere possesses of supporting life and combustion, and of which we have formerly spoken under the name of oxygen. Every nine ounces of water contain eight ounces of oxygen, the remainder being made up of another and very peculiar substance, termed hydrogen. Hydrogen is a gas, invisible, colourless, and transparent, and consequently in all external characters precisely like the air we breathe. But it differs from it very much in other respects. If a lighted candle be placed in hydrogen gas, the candle is extinguished, for hydrogen does not support combustion, but the gas itself takes fire, where it mixes with the air, and burns with a pale yellowish flame, scarcely visible in broad day-light. Hence hydrogen is in its properties the very reverse of oxygen: it burns, which oxygen does not; oxygen supports combustion, which hydrogen cannot do. When hydrogen burns with oxygen, water is always formed.