Herodotus also mentions a letter engraven on plates of stone, which Themistocles, the Athenian general, sent to the Ionians, about five hundred years before the birth of Christ. Lead, however, and similar metals being less difficult to write upon, and more simple and convenient, afterwards superseded to a great extent the use of such unwieldy substances as bricks and stone. And subsequently we find others of a still more pliable texture employed, such as the skins of animals, bark, wood, and the leaves of trees. Solomon, for instance, in the Book of Proverbs, in allusion to the practice of writing upon thin slices of wood, advises his son to write his precepts upon the _tables_ of his heart. And the prophet Habakkuk was commanded to write a vision and make it plain upon _tables_, that he may run that readeth it. Solomon, as you are aware, lived a thousand years, and Habakkuk about six hundred and twenty six, before the Christian era. At a later period, Zacharias, the father of John the Baptist, when enquired of as to what he would have his child called, asked, we are told, for “a _writing table_, and wrote, saying, his name is John.” Amongst the Romans, it was customary for the public affairs of every year to be committed to writing by the high priest, and published on a table; such tables being exposed to view, either in their market-places or temples, in order that the people might have an opportunity of becoming acquainted with their contents. At an early period in their history, both Greeks and Romans appear to have commonly used either those plain wooden boards, or boards covered with wax. It is probable, that at first the tables were written upon just as they were planed, and that the overlaying them with wax was an improvement on that invention. A very decided advantage being thus obtained, in the facility afforded for erasing any inaccuracies that might have occurred, and consequently of correcting the manuscript. The practice of writing upon tablets of one kind or another, appears not to have been entirely laid aside, until the commencement of the fourteenth century; and, indeed, even in our day, tablet books of ivory are occasionally used, for writing upon with black lead pencils. The use of _boards_ was in some measure superseded by that of the leaves of palm, olive, poplar, and other trees. And, although in Europe, all these disappeared upon the introduction of the papyrus and parchments, in some countries the use of them remains even to this day. Perhaps a record of this old custom may still be found in the word _leaf_, which we continue to apply to sheets of paper, when sewed up into the form of a book. According to the account of Pliny, the Egyptians were the first to use the palm leaf, and books written on it are still preserved in the East India Museum, as also in the Library of the British Museum.