from furnaces charged with portions of gold which had been admittedly slipped in while it was molten.
"Some alchemists have imposed on their spectators with nails half of iron and half of gold or silver. They make believe that they effect a real transmutation of half of these nails by dipping it into a pretended tincture. Nothing is more seductive at first; but it is, after all, only a trick. The nails, which seemed to be all iron, were really in two pieces neatly soldered, the gold or silver to the iron, and washed with an iron-colored wash, that disappeared when they were dipped into a suitable liquid. Of this character was the gold and iron nail formerly to be seen in the cabinet of the Grand Duke of Tuscany; of like nature are those half-silver and half-iron nails which I present to this society today. Such also was the knife which a monk once presented to Queen Elizabeth of England, in the earlier years of her reign, the end of the blade of which was of gold; as well also those knives, half silver and half iron, which a famous quack scattered a few years ago over Provence. It is true that they say that this last performer operated on knives that were given him, and which he gave back after a time with the ends of the blades silvered. But there is reason for supposing that the change was made by cutting off the end of the blade and soldering on a similar end of silver.
"There have been also pieces of money and medals half gold and half silver. Such pieces were said to have been originally all silver, half of which was turned into gold by dipping them half-way into the philosopher's mixture, without the outer form or the engraved designs being essentially changed. I say that no such medal was ever all silver, but that they were in two pieces, one of silver the other of gold, so soldered together as to preserve the proper arrangement of the characters. The thing could be easily done by having several silver medals of the same kind, a little worn, and making molds of them in sand for casting copies in gold. The sand would not even have to be very fine. Then let the medals be cut exactly to rule, fitted by filing, and the complementary halves soldered together with care, to have the designs precisely correspond. Any trifling flaw could be mended with the graver. The part of the medal that is of gold, having been cast in sand, looks a little grainy and is rougher than the silver part, which was pressed; but this fault was given out to be an effect or a proof of the transmutation; because a given quantity of silver, having a larger volume than a like quantity of gold, the silver shrunk some in changing into gold, leaving the pores or spaces that constituted the grain. The operator, besides, took pains to make the golden part a little thinner than the silver, to keep up the semblance; and to use only as much or not quite as much
