More than two-thirds of the earth’s surface is water, so that in mere quantity alone it is the most important substance with which we are acquainted. Without it life would be impossible, for, owing to its quality of dissolving other bodies, it may be regarded as the great purifier, as well as the vehicle which brings nourishment to plants and animals alike.

Not only is water useful, but is among the most beautiful of Nature’s products. It has carved the valleys between mountain ranges by its slow dropping for ages, and has made the fairy glens by rushing down their sides in torrents. The stately rivers and the roaring oceans are but forms of its might.

In another state it works out those fantastic grottoes, mountains and fields of glittering white, that make the Polar seas the very head center of dreamland.

In still another form it paints the rainbow in the sky, and hangs like a veil over the landscape, passing from the most delicate blue over the plain to the deep purple clinging to distant hills.

To it the golden and red hues of sunrise and sunset are due. The light fleecy clouds that speak the beauty of spring, and the great thunder stocks that gleam, with lightning flashes are all composed of water, and water alone.

It drives our engines and machinery, and speeds our ships across the sea. Neither is it confined to this earth alone, for astronomers tell us that vast seas and even clouds can be seen on the next great planet to the earth, Mars.

Surely, then, as this wondrous substance is examined, the ancients can be excused for worshiping the ocean as a god, and the old alchemists for believing it to be an element.

Nevertheless, water is not a simple substance. It is composed of two gases, which must be combined before water is produced. These gases are oxygen and hydrogen. Every atom of water consists of one part of the former gas and two parts by volume of the latter. This you may prove in the following way:

Buy a piece of sodium, a metal that must not be touched with the fingers, and thrust it into a small one-ounce jar half full of water; cork the jar tightly.

Through a hole in the cork pass a glass tube, the outer end being drawn in a flame to a fine point. Apply a light at the end of the tube. The escaping gas will catch fire and burn with a light blue flame. This gas is hydrogen.

Next empty the jar and fill with warm water, and place by means of another cork a small glass jar on to the tube. Into the lower jar drop a piece of blazing hot platinum. Repeat this again and again with the same piece of platinum, being careful not to uncork the upper jar, so that every time the metal is dropped into the lower jar, you remove the upper jar with the tube and two corks. After doing this a dozen times or more take a match that is still glowing after having been extinguished, and plunge it into the upper jar. It will burst into flame immediately, and the gas in the upper jar is oxygen.