Thus in Egypt, Thoth the Second, known to the Greeks as Hermes Trismegistus, a fabulous demi-god of the period succeeding the reign of the great gods, is said to have invented the alphabet and the art of writing. The analysis of primary sounds varies a little in different times and countries in order to suit peculiarities in the pronunciation of different races and convenience in writing; but about sixteen primitive sounds, which is the number of the letters of the first alphabet brought by Cadmus to Greece, are always its basis. In our own alphabet it is easy to see that it is not formed on strictly scientific principles, some of the letters being redundant. Thus the soft sound of 'c' is expressed by 's,' and the hard sound by 'k'; and 'x' is an abbreviation of three other letters, 'eks.' Some letters also express sounds which run so closely into one another that in some alphabets they are not distinguished, as 'f' and 'v,' 'd' and 't', 'l' and 'r'; while some races have guttural and other sounds, such as 'kh' and 'sj,' which occur so frequently as to require separate signs, while they baffle the vocal organs of other races, and in some cases syllables which frequently occur, instead of being spelt out alphabetically, are represented by single signs. But these are mere details, the question substantially is this--if a collection of unknown signs is phonetic, and we can get any clue to its alphabet, it can be read; if not it must remain a sealed book. To apply this to hieroglyphics; it had been long known that the monuments of ancient Egypt were carved with mysterious figures, representing commonly birds, animals, and other natural objects, but all clue to their meaning had been lost. It seemed more natural to suppose that they were ideographic; that a lion for instance represented a real lion, or some quality associated with him, such as fierceness, valour, and kingly aspect, rather than that his picture stood simply for our letter 'l.' The long-desired clue was afforded by the famous Rosetta stone. This is a mutilated block of black basalt, which was discovered in 1799 by an engineer officer of the French expedition, in digging the foundations of a fort near Rosetta. It was captured, with other trophies, by the British army, when the French were driven out of Egypt, and is now lodged at the British Museum. It bears on it three inscriptions, one in hieroglyphics, the second in the demotic Egyptian character employed for popular use, and the third in Greek. The Greek can of course be read, and it is an inscription commemorating the coronation of Ptolemy Epiphanes and his Queen Arsinoe, in the year 196 B.C. It was an obvious conjecture that the two Egyptian inscriptions were to the same effect, and that the Greek was a literal translation of this. To turn this conjecture, however, into a demonstration, a great deal of ingenuity and patient research were required. The principle upon which all interpretation