Of these metals gold was supposed to be the only one that was perfect, and the belief was general that if the others could be purified and perfected they would be changed to gold. Many of the old chemists worked faithfully and honestly to accomplish this, but the path to wealth seemed so direct and the means for deception were so ready and simple, that large numbers of quacks and charlatans entered the field and held out the most alluring inducements to dupes who furnished them liberally with money and other necessaries in the hope that when the discovery was made they would be put in possession of unbounded wealth. These dupes were easily deceived and led astray by simple frauds, which scarcely rose to the level of amateur legerdemain. In the "Memoirs of the Academy of Sciences" for 1772, M. Geoffroy gives an account of the various modes in which the frauds of these swindlers were carried on. The following are a few of their tricks: Instead of the mineral substances which they pretended to transmute they put a salt of gold or silver at the bottom of the crucible, the mixture being covered with some powdered crucible and gum water or wax so that it might look like the bottom of the crucible. Another method was to bore a hole in a piece of charcoal, fill the hole with fine filings of gold or silver, stopping it with powered charcoal, mixed with some agglutinant so that the whole might look natural. Then when the charcoal burned away, the silver or gold was found in the bottom of the crucible. Or they soaked charcoal in a solution of these metals and threw the charcoal, when powdered, upon the material to be transmuted. Sometimes they whitened gold with mercury and made it pass for silver or tin, and the gold when melted was exhibited as the result of transmutation. A common exhibition was to dip nails in a liquid and to take them out apparently half converted into gold; these nails consisted of one-half iron neatly soldered to the other half, which was gold, and covered with something to conceal the color. The paint or covering was removed by the liquid. A very common trick was the use of a hollow, iron stirring rod; the hollow was filled with gold or silver filings, and neatly stopped with wax. When used to stir the contents of the crucible the wax melted and allowed the gold or silver to fall out. These frauds were rendered all the more easy because of certain statements which were current in regard to successful attempts to convert lead and other metals into gold. These accounts were vouched for by well-known chemists and others of high standing. Perhaps the most famous of these is that given by Helvetius in his "Brief of the Golden Calf; Discovering the Rarest Miracle in Nature; how by the smallest portion of the Philosopher's Stone, a great piece of common lead was totally transmuted into the purest transplendent gold, at the Hague in 1666." The following is Brande's abridgment of this singular account.