SAND out of a River near Conimbria, in which there are some few sparks of GOLD. Together with a Knob of Gold fus'd out of it. Given by Sir Robert Southwell.

Gold hath the least variety of regular figure, in the Ore, of any Metal. Because, more solid, and therefore, less wanton, than the rest. 'Tis a rare Specimen, mention'd by Georgius de Sepibus, (a) (a) Mus. Roman. which he calls Aurum Ramescens. The Ductility of Gold is admirable: one Grain, in Leaves, is extended to above fifty inches square: and one ounce employ'd in gilding small Hair-Wyre, will be extended to almost an 100 miles in length; as Mr. Boyle hath observ'd. (b)(b) Of Effluv. p. 13. & 14.

The Uses of Gold for Vessels, Coins, Armour, Garments, &c. are infinite. The Luxury of Galienus the Emperour, taught him to powder his Hair with the Dust of Gold. Some Painters, saith Ambrosinus, (c) (c) Aldrov. Mus. Met. hang plated Gold over Vinegar, whereby is produced a pure Blew (as Ceruss out of Lead) which they prefer before the Ultramarine. Of the Art of Refining, see the Phil. Transactions, (d)(d) N. 142. Communicated by Dr. Christ. Merret.

Chymically manag'd, it is reduced to several forms, called Aurum Potabile, Aurum fulminaus, A. Vitæ; as also, Auri Calx, Crocus, Sal, Sulphur, Tinctura, Oleum, Vitriolum, Flos: of which see Libavius, Crollius, Schroder, and others. One principal use of Gold in Medicine is, for the Correction of Mercurial Medicines. The original use of Leaf-Gold in Electuaries, and divers other Preparations, was not only for better grace, but from the opinion of its adding Virtue to them. And Plates of Gold, anciently, have been us'd, especially for Children, as an Amulet. Which I take to be the true reason, why the Kings of England hang a piece of Gold upon those they Touch.