And now for our last yarn, a true one. Some years ago a large vessel, having on board a valuable cargo, including gold bars, was run down and sunk by a steamship in the Thames between Northfleet and Gravesend. She was afterwards successfully raised by Captain George Wilson, of Milton, the famous oyster place, near Sittingbourne, in Kent, and which is also famous for its divers. It is principally, however, to the names of the vessels concerned that attention is directed. The _United Kingdom_ was run down by the _Queen of Scotland_! CHAPTER VIII. THE OCEAN AND SOME OF ITS PHENOMENA. The Saltness of the Sea—Its Composition—Tons of Silver in the Ocean—Currents and their Causes—The Great Gulf Stream—Its Characteristics—A Triumph of Science—The Tides—The Highest Known Tides and Waves—Whirlpools—The Maelström—A Norwegian Description—Edgar Allan Poe and his Story—Rescued from the Vortex—The “Souffleur” at the Mauritius—The Colour of the Sea—Its Causes—The Phosphorescence of the Ocean—Fields of Silver—Principally Caused by Animal Life. Many features and phenomena of the ocean have been incidentally noted in the foregoing pages; but there are points, hitherto untouched, which deserve our attention. Its saltness is due, not merely to the presence of chloride of sodium, or what we call common salt, but to a large number of other minerals, including the chlorides of magnesium and potassium, the sulphates of magnesia and lime, carbonate of lime, sulphuretted hydrogen, bromide of magnesia, hydrochlorate of ammonia, iodine, iron, copper, and even silver, varying in proportion according to locality. The copper plates of a ship examined at Valparaiso showed unmistakable traces of silver deposits. Calculations have been made showing that the ocean contains 2,000,000 tons of silver. In 1,000 grains of sea‐water there are thirty‐eight grains of these ingredients and some little organic matter. The saltness of the sea is generally greater towards the poles, but to this statement there are exceptions. In parts of the Irish Channel the water contains salts equal to the fortieth of its weight, the saline matter rising to one‐sixteenth of its weight off the coast of Spain. In many places the ocean is less salt at the surface than at the bottom. Its saltness increases its density and its buoyancy.