The first use of quicksilver is commonly reckoned a Spanish invention, discovered about the middle of the sixteenth century; but it appears from Pliny, that the ancients were acquainted with amalgam and its use, not only for separating gold and silver from earthy particles, but also for gilding[29]. Vitruvius describes the manner of recovering gold from cloth in which it has been interwoven. The cloth, he says, is to be put into an earthen vessel, and placed over the fire, in order that it may be burnt. The ashes are to be thrown into water, and quicksilver added to them. The latter attracts the particles of the gold, and unites with them. The water is then to be poured off, and the residue put into a piece of cloth; which being squeezed with the hands, the quicksilver, on account of its fluidity, oozes through the pores, and the gold is left pure in a compressed mass[30]. Isidore of Seville says also, that quicksilver is best preserved in vessels of glass, as it penetrates all other substances; and that without it neither silver nor brass can be gilded[31]. Modern mineralogists however have this advantage over the ancient, that they know how to separate the quicksilver from gold and silver without losing it. Instead of exposing the amalgam to an open fire, as formerly, and driving off the volatile metal, it is now put into a retort, and the quicksilver is collected in a receiver for further use. Those also who wash gold from the sand found near rivers, use quicksilver before their work is completed; and I am strongly inclined to believe that this method prevailed in Germany long before the discovery of the mines in America. In the year 1582, John Michael Heberer described the washing of gold as he saw it practised at Selz, not far from Strasburg; and at that time quicksilver had been long employed for that purpose. In Treitlinger’s Dissertation, also, concerning the collecting of gold, and particularly in the Rhine, there is a description of the manner in which gold sand is washed by means of quicksilver, but no date is mentioned[32].