himself, folding up the manuscript of Nicolas Flamel. "The hermetic
philosophers discovered--and modern science, after long evading the
issue, no longer denies--that the metals are compounds, and that their
components are identical. They vary from each other according to the
different proportions of their elements. With the aid of an agent which
will displace these proportions one may transmute mercury, for example,
into silver, and lead into gold.

"And this agent is the philosopher's stone: mercury--not the vulgar
mercury, which to the alchemists was but an aborted metallic sperm--but
the philosophers' mercury, called also the green lion, the serpent, the
milk of the Virgin, the pontic water.

"Only the recipe for this mercury, or stone of the sages, has ever been
revealed--and it is this that the philosophers of the Middle Ages, the
Renaissance, all centuries, including our own, have sought so
frantically.

"And in what has it not been sought?" said Durtal, thumbing his notes.
"In arsenic, in ordinary mercury, tin, salts of vitriol, saltpetre and
nitre; in the juices of spurge, poppy, and purslane; in the bellies of
starved toads; in human urine, in the menstrual fluid and the milk of
women."

Now Gilles de Rais must have been completely baffled. Alone at
Tiffauges, without the aid of initiates, he was incapable of making
fruitful experiments. At that time Paris was the centre of the hermetic
science in France. The alchemists gathered under the vaults of Notre
Dame and studied the hieroglyphics which Nicolas Flamel, before he died,
had written on the walls of the charnal Des Innocents and on the portal