The experimenter would now proceed to heat a quantity of a mineral containing lead in an open vessel made of pulverized bones; the lead slowly disappeared, and at the close of the experiment a button of silver remained. Might he not triumphantly assert that he had transmuted lead into silver?
In order that the doctrine of the transmutation of metals might rest on yet surer evidence, the alchemist placed a piece of copper in spirits of nitre (nitric acid); the metal disappeared; into the green liquid thus produced he then placed a piece of iron; the copper again made its appearance, while the iron was removed. He might now well say that if lead was thus demonstrably changed into silver, and copper into iron, it was, to say the least, extremely probable that any metal might be changed into any other provided the proper means for producing the change could be discovered.
But the experimental alchemist had a yet stranger transmutation wherewith to convince the most sceptical. He poured mercury in a fine stream on to melted sulphur; at once the mercury and the sulphur disappeared, and in their place was found a solid substance black as the raven's wing. He then heated this black substance in a closed vessel, when it also disappeared, and in its place there was found, deposited on the cooler part of the vessel, a brilliantly red-coloured solid. This experiment taught lessons alike to the alchemist, the philosopher, and the moralist of these times. The alchemist learned that to change one kind of matter into another was an easy task: the philosopher learned that the prevalence of change or transmutation is one of the laws of Nature: and the moralist learned that evil is not wholly evil, but contains also some germs of good; for was not the raven-black substance emblematical of the evil, and the red-coloured matter of the good principle of things?[1]
On such experimental evidence as this the building of alchemy was reared. A close relationship was believed to prevail through the whole phenomena of Nature. What more natural then than to regard the changes which occur among the forms of matter on this earth as intimately connected with the changes which occur among the heavenly bodies?
Man has ever been overawed by the majesty of the stars; yet he has not failed to notice that the movements of these bodies are apparently capricious. The moon has always been to him a type of mutability; only in the sun has he seemed to find a settled resting-point. Now, when we remember that in the alchemical scheme of things the material earth and material heavens, the intellectual, the moral, and the spiritual world were regarded as one great whole, the parts of which were continuously acting and reacting on each other, we cannot wonder that the alchemist should regard special phenomena which he observed in his laboratory, or special forms of matter which he examined, as being more directly than other phenomena or other forms of matter, under the influence of the heavenly bodies. This connection became gradually more apparent to the student of alchemy, until at last it was fixed in the language and the symbols which he employed.
Thus the sun (Sol) was represented by a circle, which likewise became the symbol for gold, as being the most perfect metal. The moon (Luna) was ever changing; she was represented by a half-circle, which also symbolized the pale metal silver.
Copper and iron were regarded as belonging to the same class of metals as gold, but their less perfect nature was denoted by the sign + or ↑. Tin and lead belonged to the lunar class, but like copper they were supposed to be imperfect metals. Mercury was at once solar and lunar in its properties.
These suppositions were summed up in such alchemical symbols as are represented below—
