Page:Physical Geography of the Sea and its Meteorology.djvu/42

16 in office, water, whether fresh or salt, solid, fluid, marvellous in its powers.

42. It caters on land for insects of the sea.—It is one of the chief agents in the manifold workshops in which and by which the earth has been made a habitation fit for man. Circulating in veins below the surface, it pervades the solid crust of the earth in the fulfilment of its offices; passing under the mountains it runs among the hills and down through the valley's in search of pabulum for the moving creatures that have life in the sea. In rivers and in rain it gathers up by ceaseless lixiviation food for the creatures that wait upon it. It carries off from the land whatever of solid matter the sea in its economy requires.

43. Leaching.—The waters which dash against the shore, which the running streams pour into the flood, or with which the tides and currents scour the bottom of their channel ways, have soaked from the soil, or leached out of the disintegrated materials which strew the beach or line the shores, portions of every soluble ingredient known in nature. Thus impregnated, the laughing, dancing waters come down from the mountains, turning wheels, driving machinery, and serving the manifold purposes of man. At last they find their way into the sea, and so make the lye of the earth brine for the ocean.

44. Solid ingredients.—Iron, lime, silver, sulphur, and copper, silex, soda, magnesia, potash, chlorine, iodine, bromine, ammonia, are all found in sea-water; some of them in quantities too minute for the nicest appliances of the best chemists to detect, but which, nevertheless, are elaborated therefrom by physical processes the most exquisite.

45. Quantity of silver in the sea.—By examining in Valparaiso the copper that had been a great while on the bottom of a ship, the presence of silver, which it obtained from the sea, was detected in it. It was in such quantities as to form the basis of a calculation, by which it would appear that there is held in solution by the sea a quantity of silver sufficient to weigh no less than two hundred million tons, could it all, by any process, be precipitated and collected into a separate mass.

46. Its inhabitants—their offices.—The salts of the sea, as its solid ingredients may be called, can neither be precipitated on the bottom, nor taken up by the vapours, nor returned again by the rains to the land; and, but for the presence in the sea of certain agents to which has been assigned the task of collecting these