The homogeneous characters of this fluid admit of no alteration, and, like atmospheric air, are still obtained as pure most probably as when they first emerged from chaotic matter. The same principles are found in the clouds, the fogs, the dews, the rain, the hail, and the snow. For the preservation of the world it was indispensable that water should be endowed with the property of ever retaining its fluid form, and in this respect become subject to a law different from that of other bodies, which change from fluid to solid. This is a deviation from a general decree of Nature. Were it not for this wise provision of the Creator, the world would shortly have been converted into a frozen chaos. All bodies contract their dimensions, and acquire a greater specific gravity by cooling; but water is excepted from this law, and becomes of less specific gravity, whether it be heated, or cooled below 42 deg. 5'. Were it not for this exemption, it would have become specifically heavier by the loss of its caloric, and the waters that float on the surface of rivers would have sunk as it froze, until the beds of rivers would have been filled up with immense masses of ice. From the observations of Perron, there is reason to believe that the mountainous accumulations of ice that have hitherto arrested the progress of polar navigators have been detached from the depths of the ocean to float upon its surface. This circumstance would account for the difference of temperature of the sea according to its depth. The experiments of Perron, made with an instrument of his own invention, which he called the thermobarometer, gave the following results: 1st, The temperature of the sea upon its surface, and at a distance from shore, is at the meridian, lower than that of the atmosphere in the shade; much more elevated at midnight, but in a state of equilibrium morning and evening. 2nd, The temperature rises as we approach continents or extensive islands. 3rd, At a distance from land, the temperature of the deep parts of the sea is lower than that of the surface, and the cold increases with the depth. It is this circumstance which led this ingenious philosopher to conclude that even under the equator the bottom of the sea is eternally frozen. Humboldt is of a contrary opinion, and maintains that the temperature is from two to three degrees lower in shallow water; and he therefore is of opinion that the thermometer might prove of material use to navigators. He attributes this diminution of temperature to the admixture of the lower bodies of water with that of the surface. Who is to decide between these two ingenious experimentalists? "Experientia fallax, judicium difficile." The curious reader may consult in this investigation the tables of Forster in Cook's second voyage, those of Lord Mulgrave when Captain Phipps, and various other navigators.