378	METALS—THE NOBLER.
	index of perfection and simplicity, because enclosing the greatest space under the least superficies; all straight lines drawn from its centre to the circumference being equal. Gold was betokened as the most simple metal, the most perfect, and the heaviest, because it includes the greatest quantity of matter under the least surface. The character for the Moon (signifying silver) was a half circle, because it is half Gold, as chemists agree, but that half lies hid. The character for Copper (Venus) denotes that the body is of Gold, joined with some corrosive menstruum. The explanation of the character for Lead was the same as for Tin, but inverted, with the corrosive passing through the middle. Neither of these two significations is clear. A skull—(caput mortuum)—was designed, and shown at the end of the metallic symbols; this " caput mortuum" meaning the residue of dregs left in the retort, or alembic, after distillation. The Arabian physicians were in the habit of using Gold,—giving the metal itself in a fine powder—as a medicine, which proved highly curative in their hands. Far later, in 1811, Chretien revived in Paris the curative use of powdered metallic Gold; making public his Observations sur un Nouveau Remede dans le Traitement des Maladies Veneriennes, et Lymphatiques, wherein he communicated a number of cases illustrating the curative value of this medicine in syphilis, and scrofula. He stated that finely powdered Gold-leaf produces the same beneficial effect as the Chloride, or the Oxide, of the metal. The nasal action of the medicine has led to its successful use in raw soreness within the nostrils, with formation of crusts therein, attended with offensive smelling of putrid odours.