By partly roasting galena with access of air and then raising the temperature with exclusion of air, the brittle useless metal galena can be converted into the useful base metal lead. Now if this base metal is heated on a bone ash cupel, which can absorb the litharge which is formed, all the lead disappears and there is left a small amount of precious metal--silver. This precious metal when treated with spirits of nitre (nitric acid) in many cases leaves a small residue of a metal still more precious--gold.
This simple piece of metallurgy, translated into the terms of an alchemist ran thus: "You see before you a piece of galena, useless and valueless. By my art I can transmute it into lead which is useful but base. If I put the lead into a cupel and reheat it, I will transmute it into silver, and then if the silver be treated with spirits of nitre, we will transmute it into gold. Of course," the alchemist would add, "we have a good deal less gold in the end, than we had galena in the beginning--but you must realize that our science is not yet perfected--perhaps if we had a little more money to spend on equipment--?" But it was not all charlatanry. By their lights the alchemists were right; certainly they started with the useless and ended with the precious, but their balances were crude, and the quantitative relationships between the raw materials and the products were not considered sufficiently important.
They did obtain gold as the last stage in a process of transmutation from galena. But it would need more than equipment to produce an equal quantity of their most precious metal from their most useless. There is twenty per cent less lead than there was galena, ninety-nine per cent less silver than there was lead, and ninety per cent less gold than there was silver. When quantities were totally ignored, what did it matter?
Today we know that there was no transmutation taking place, that galena is an ore of lead, and that lead often contains both silver and gold. We know too that galena from some mines contains more silver and gold than that from other mines. The percentage of lead obtainable from pure galena is the same in all cases.
Alchemy persists. A substantial smelter was built on the theory that more gold can be obtained from ores than is shown in the fire assays--which, by tests innumerable, has been shown to be capable of extracting all but a very minute percentage of the gold in ore. It is our belief that the new smelter was built with the idea that it can transform some of the baser metals into gold.
The Chanouns Yemannes Tale is an excellent commentary on the trickery of alchemists, and they have always been open to the charge of charlatanry; but so have the forerunners of all science. Many sincerely believed that chemical changes were possible, and later they made notable advances in metallurgy and chemistry, developing new drugs which have been a great boon and help in easing pain and prolonging life.
Their belief in the transmutation of metals may have been unjustified, but just as the microcosm and the macrocosm have received a sudden proof in the field of atoms and planets, so the transmutation of metals has been discovered in recent years through the radio-active elements.