age of inductive science.

But there was one experiment to which the alchemist pinned his
faith in showing that metals could be "killed" and "revived,"
when proper means were employed. It had been known for many
centuries that if any metal, other than gold or silver, were
calcined in an open crucible, it turned, after a time, into a
peculiar kind of ash. This ash was thought by the alchemist to
represent the death of the metal. But if to this same ash a few
grains of wheat were added and heat again applied to the
crucible, the metal was seen to "rise from its ashes" and resume
its original form--a well-known phenomenon of reducing metals
from oxides by the use of carbon, in the form of wheat, or, for
that matter, any other carbonaceous substance. Wheat was,
therefore, made the symbol of the resurrection of the life
eternal. Oats, corn, or a piece of charcoal would have "revived"
the metals from the ashes equally well, but the mediaeval
alchemist seems not to have known this. 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