An opportunity soon offered itself to try the powers of the famous powder.  Mr. J. Howell, having been wounded in endeavoring to part two of his friends who were fighting a duel, submitted himself to a trial of the Sympathetic Powder.  Four days after he received his wounds, Sir Kenehn dipped one of Mr. Howell’s gaiters in a solution of the Powder, and immediately, it is said, the wounds, which were very painful, grew easy, although the patient, who was conversing in a corner of the chamber, had not, the least idea of what was doing with his garter.  He then returned home, leaving his garter in the hands of Sir Kenelm, who had hung it up to dry, when Mr. Howell sent his servant in a great hurry to tell him that his wounds were paining him horribly; the garter was therefore replaced in the solution of the Powder, “and the patient got well after five or six days of its continued immersion.”

King James First, his son Charles the First, the Duke of Buckingham, then prime minister, and all the principal personages of the time, were cognizant of this fact; and James himself, being curious to know the secret of this remedy, asked it of Sir Kenelm, who revealed it to him, and his Majesty had the opportunity of making several trials of its efficacy, “which all succeeded in a surprising manner.” [Dict. des Sciences Medieales.]

The king’s physician, Dr. Mayerne, was made master of the secret, which he carried to France and communicated to the Duke of Mayenne, who performed many cures by means of it, and taught it to his surgeon, who, after the Duke’s death, sold it to many distinguished persons, by whose agency it soon ceased to be a secret.  What was this wonderful substance which so astonished kings, princes, dukes, knights, and doctors?  Nothing but powdered blue vitriol.  But it was made to undergo several processes that conferred on it extraordinary virtues.  Twice or thrice it was to be dissolved, filtered, and crystallized.  The crystals were to be laid in the sun during the months of June, July, and August, taking care to turn them carefully that all should be exposed.  Then they were to be powdered, triturated, and again exposed to the sun, again reduced to a very fine powder, and secured in a vessel, while hot, from the sunshine.  If there seem anything remarkable in the fact of such astonishing properties being developed by this process, it must be from our short-sightedness, for common salt and charcoal develop powers quite as marvellous after a certain number of thumps, stirs, and shakes, from the hands of modern workers of miracles.  In fact the Unguentum Armarium and Sympathetic Powder resemble some more recent prescriptions; the latter consisting in an infinite dilution of the common dose in which remedies are given, and the two former in an infinite dilution of the common distance at which they are applied.

Whether philosophers, and more especially metaphysicians, have any peculiar tendency to dabble in drugs and dose themselves with physic, is a question which might suggest itself to the reader of their biographies.