Let us for a moment consider this fluid we call water, especially sea water. Chemically speaking, pure water is one of the rarest things—that is, water absolutely free from all foreign matter, divested of everything save hydrogen and oxygen in the combining proportions, by weight one part of hydrogen to eight of oxygen; by volume, two of hydrogen to one of oxygen, we have pure water—an _oxide_ of _hydrogen_. But absolutely pure water must be prepared in a vacuum, and it must never have contact with air of any kind. Pure water would be instantly fatal to any animal that had to breathe it with gills, as a fish, simply because it contains no oxygen in solution, which the animal can use to oxydize the blood in the gills. We in breathing air get oxygen by decomposing the air, but animals that breathe in water do not decompose the water, but take from it the free oxygen that is found mechanically mixed with the water. Pure water, being the standard of measurement of liquors and solids, is taken as one or one thousand. Sea water is 1,020, or near, whilst the water of the Dead Sea, or of lakes and seas with no outlet go as high as 1,225, or even to a point where they are saturated, or can not dissolve any more. Such is the case with the Great Salt Lake of Utah, and Mono Lake, of California. Water of this kind is not usually inhabited by any kind of gill breathing animals. How did the sea become salt? By the washings out of the land, and the disintegration of the rocks by the elements, such as ice, wind, heat, rain, etc. The sun causes evaporation; so that the sea is being constantly lifted into the air and carried in the shape of clouds to the land, where it is drawn down and flows again into the sea. The solid matter carried down to the sea does not return. It remains in solution, or is deposited on the bottom. The clouds contain almost pure water. They distribute the visible ocean throughout the invisible air. The rocks and the trees, the animals and the air all receive their respective shares of water; and in the course of time it is returned to the sea. Were evaporation to continue at the present rate, it would require about 1,600 years before the ocean beds would become dry land. But in one way and another there is just as much water returned to the sea each year as is taken out. Not one drop is lost. The seas may change their beds—they may flow where the forest now stands, and their waters may cover our highest mountains, and their bottoms may rise many hundred feet above their present level, and still there will not be one drop more or less of the great body of water that now covers more than two-thirds of the earth’s surface. The sea will still claim its own. The water that floats to-day in the clouds may to-morrow course through some giant tree of the forest, or be taken up in forming a beautiful crystal, or aid in the bloom and fragrance of a flower, or be taken into the lungs of some animal and