It need not be supposed that any definite table of the planetary symbols was ever drawn up and agreed to. These only very gradually became uniform. Even the association of the planets and the metals was by no means invariable in different nations. Among the Persians, for example, copper was assigned to Jupiter; but the Egyptians dedicated a compound of gold and silver called electron to him, while in more recent systems Jupiter and tin are allied. Venus controlled tin according to Persian lore; but the Egyptian attribution of brass or copper to her has prevailed. Iron belonged to Mercury before quicksilver was recognised as a metal and at that time Mars was the god-father of an alloy similar to bronze. The oldest table known is one given by Olympiodorus in the fifth century, and in that electron is still associated with Jupiter and tin with Hermes (Mercury). Berthelot’s laborious researches into the origin of alchemy, and his reproductions of ancient manuscripts show that while signs were used by the ancient Greek writers of about the first century of our era, they were not used by the Latin authors, but seem to have been in full adoption in the Middle Ages. The manuscript of St. Mark at Venice, which Berthelot believed was written about the year A.D. 1000, probably for some prince, contains a multitude of these symbols. A regular system is followed. Gold, for example, is represented by [symbol]; gold filings by [symbol]; gold leaf, thus [symbol]; and a combination of gold and silver by [symbol]. A similar modification of the original symbols is found in connection with the other metals. There is scarcely any allusion to the symbols in the Arabic manuscripts, for that race had a holy horror of all forms of Greek paganism, though it may be noted that their physicians made a superstition of the practice of bleeding on Tuesdays and Wednesdays only, unconscious perhaps of the origin of this ritual, which depended on the fact that Mars, the god of blood and iron, superintended Tuesday’s operations, and Mercury, who had the management of the humours, was in charge on Wednesdays. It was really not until the fifteenth, sixteenth, and seventeenth centuries, when the European alchemists were trying to find a way to transmute the baser metals into gold, that the code became “conventionalised.” As already stated, the signs for the seven metals have not been invariable, but for many centuries they have been distributed thus:-- ☉ Sol, the Sun, Gold. ☽ Luna, the Moon, Silver. ♃ Jupiter, Tin. ♀ Venus, Copper. ♂ Mars, Iron. ☿ Mercury, Quicksilver. [astrological symbol] Saturn, Lead.