THE ORIGIN OF THE SALT OF THE SEA.

Daily Telegraph (Napier), Issue 3127, 6 July 1881, Page 4

THE ORIGIN OF THE SALT OF THE SEA.

Sonncnstadt has found that tbe water of the ocean contains gold in solution, and he estimates the quantity at nine-tenths of a gramme (about 14 grains troy) to every ton of sea water. Many years ago silver was found in the sea water, in spite of the apparent insolubility of its chloride. Minute analysis, when exhaustively applied, appears to bring out from sea water any and every element thus sought for. Many authors have treated the saltness of the sea, as a great physical mystery, but a few simple considerations will, I think, prove pretty clearly that there would be far more reason for wonderment if the sea were composed of fresh water. The ocean covers the lower valleys of the earth, and tho land generally slopes towards it. It thus receives nearfv all the drainage and washings of the exposed surface of the earth. Some of the materials of the solid earth are readily soluble in water; none are absolutely insoluble. Therefore the rain that falls upon the earth must exert its solvent power, must take up as much as it can of whatever it meets on its way downwards, and carry this dissolved mattor into the general receptacle. When the water leaves the ocean again by rising as vapour it does not carry tho dissolved earthy matter with it,_ but is distilled as pure water, to fall again and re-enter the ocean as river water, or water more or less hardened by tho matter it has dissolved from the earth. Thus, every river or streamlet that pours into the sea carries with it fresh contributions of salinity, and this having gone on as long as the surface of the earth has consisted of land and water, the saltness of the ocean i 3 but a natural and necessary matter of course. This view of the origin of the saline matters dissolved in the ocean is confirmed by an examination of other bodies of water similarly related to surrounding land, i.e., of lakes which occupy hollows in tho land and receive the inflow of a river or rivers, without having any outlet but that which is due to evaporation. Such model oceans are essentially abundant on the great table land of Asia, extending northward from the Himalayas and their eastward extensions to the Altai and the general ridge which forms the watershed of the great rivers of Russia, that vast region where tho Chinese, Russian, and British empires meet, and which has been aptly named the " Eoof Of tbe World," The boundary mountains

forming tho ridge of this roof or plateau slop: outwards to the sea and inwards to the great elevated basin, tho bottom of which is from tea to fifteen thousand feet higher than the sea level. The "thousand and one" rivers and rivulets, that flow inwards all terminate in small selfcontained seas, that have no other outlet than by evaporation. Thus all the soluble contributions of the rivers remain, and all these pools are salt lakes of varying density, some even more saline than the ocean itself. A detailed map of this wild country displays a number of tadpole like delineations, or bags with strings attached. These are the shut-up salt lakes and their tributary rivers. The salt deserts around some of these lakes indicate former extension of their waters, which probably were united, and firmed a great Asiatic Mediterranean Sea during the glacial epoch, when there T <:-3 ir : *e x'ain ■~ Mess craporatioi: n tl. ■ northern hemisphere than at present. The Sea of 4ral and the ' "aspian are but larger examples of the same series. The saltness of the»e is commonly cited in evidence of their former continuity with the ocean, but if I am right it really affords no such evidence at all, as these inland seas would be salt whether they were portions of the main oceans or independent little oceans, i.e.. ultimate receptacles of river water and all that flows with it. The Dead Sea, which receives the Jordan at one end and a multitude of minor rivers or rivulets from all its other sides, is the best-known example of a saline ultimate receptacle of river waters. This, as everybody knows, is a sea or lake of brine. Its redundance of saline matter is at once explained by the above hypothesis, seeing that it is situated in a region of great evaporation, and that it receives the drainage of a disproportionately large area. The total area of land draining into the great ocean does not exceed onefourth of its own area, while the Dead Sea receives the drainage and soluble matter of an area above twenty times greater than its own. It would extend this note too far to describe in detail the saline constituents of the ocean, but I may state generally that each particular base and acid is there found to exist in a proportion nearly corresponding to the general solubility of its ordinary compounds ; showing that tho rain water in its couise over the earth carries down into the sea the most soluble materials of the land and leaves them thero, and that therein lies the whole of the salt water.—W. Mattieu Williams, in the Gentleman's Magazine.