hich impostors persuaded the
world that they had succeeded in making gold, and of which so many stories
were current about this period, a very satisfactory report was read by M.
Geoffroy the elder, at the sitting of the Royal Academy of Sciences at
Paris, on the 15th of April, 1722. As it relates principally to the
alchymic cheats of the sixteenth and seventeenth centuries, the following
abridgment of it may not be out of place in this portion of our history.
The instances of successful transmutation were so numerous, and apparently
so well authenticated, that nothing short of so able an exposure as that
of M. Geoffroy could disabuse the public mind. The trick to which they
oftenest had recourse was to use a double-bottomed crucible, the under
surface being of iron or copper, and the upper one of wax, painted to
resemble the same metal. Between the two they placed as much gold or
silver dust as was necessary for their purpose. They then put in their
lead, quicksilver, or other ingredients, and placed their pot upon the
fire. Of course, when the experiment was concluded, they never failed to
find a lump of gold at the bottom. The same result was produced in many
other ways. Some of them used a hollow wand, filled with gold or silver
dust, and stopped at the ends with wax or butter. With this they stirred
the boiling metal in their crucibles, taking care to accompany the
operation with many ceremonies, to divert attention from the real purpose
of the manoeuvre. They also drilled holes in lumps of lead, into which
they poured molten gold, and carefully closed the aperture with the
original metal. Sometimes they washed a piece of gold with quicksilver.
When in this state, they found no difficulty in palming it off upon the
uninitiated as an inferior metal, and very easily transmuted it into fine
sonorous gold again with the aid of a little aquafortis.

Others imposed by means of nails, half iron and half gold or silver. They
pretended that they really transmuted the precious half from iron, by
dipping it in a strong alcohol. M. Geoffroy produced several of these
nails to the Academy of Sciences, and shewed how nicely the two parts were
soldered together. The golden or silver half was painted black to resemble
iron, and the colour immediately disappeared when the nail was dipped into
aquafortis. A nail of this description was, for a long time, in the
cabinet of the Grand Duke of Tuscany. Such also, said M. Geoffroy, was the
k