However, in this experiment the metal seemed actually to be destroyed and revivified, and, as science had not as yet explained this striking phenomenon, it is little wonder that it deceived the alchemist.
Since the alchemists pursued their search of the magic stone in such a methodical way, it would seem that they must have some idea of the appearance of the substance they sought.

Probably they did, each according to his own mental bias; but, if so, they seldom committed themselves to writing, confining their discourses largely to speculations as to the properties of this illusive substance.
Furthermore, the desire for secrecy would prevent them from expressing so important a piece of information.

But on the subject of the properties, if not on the appearance of the "essence," they were voluminous writers.

It was supposed to be the only perfect substance in existence, and to be confined in various substances, in quantities proportionate to the state of perfection of the substance.

Thus, gold being most nearly perfect would contain more, silver less, lead still less, and so on.