upon the addition of each ingredient being made exactly in the
critical moment, and in the precise degree of heat, indicated by the
colour of the vapour arising from the crucible or retort. This was
watched by the operator with inexhaustible patience; and it was often
found or supposed, that the minutest error in this respect caused the
most promising appearances to fail of the expected success. This
circumstance no doubt occasionally gave an opportunity to an artful
impostor to account for his miscarriage, and thus to prevail upon his
credulous dupe to enable him to begin his tedious experiment again.

But, beside this, it appears that those whose object was the
transmutation of metals, very frequently joined to this pursuit the
study of astrology, and even the practice of sorcery. So much delicacy
and nicety were supposed to be required in the process for the
transmutation of metals, that it could not hope to succeed but under a
favourable conjunction of the planets; and the most flourishing
pretenders to the art boasted that they had also a familiar
intercourse with certain spirits of supernatural power, which assisted
them in their undertakings, and enabled them to penetrate into things
undiscoverable to mere human sagacity, and to predict future events.


FAIRIES.

Another mode in which the wild and erratic imagination of our
ancestors manifested itself, was in the creation of a world of
visionary beings of a less terrific character, but which did not fail
to annoy their thoughts, and perplex their determinations, known by
the name of Fairies.