A late discourse made in a solemne assembly of nobles and learned men at Montpellier in France; by Sr. Kenelme Digby, Knight, &c. Touching the cure of wounds by the powder of sympathy; with instructions how to make the said powder; whereby many other secrets of nature ar unfolded. Rendred faithfully out of French into English by R. White. Gent [ Translation of "Discours fait en une célèbre assemblée, touchant la guérison des playes par la poudre de sympathie".] de Digby, Kenelm, Digby 1603-1665 - 1658

London: printed for R. Lownes, and T. Davies, and are to be sold at their shops in St. Pauls Church yard, at the sign of the White Lion, and at the Bible over against the little north door of St. Pauls Church, 1658. Duodecimo: 12.5 x 8.5 cm. Signatures: A-G¹² H⁶. Adverstisement: "Books printed for, and to be sold by, Thomas Davis", p. [1] at end. The Second edition [same year as the first] corrected and augmented, with the addition of an index. With two leaves of eighteenth century English manuscript text at the end. This copy has been expertly rebound in seventeenth century style. With two leaves of eighteenth century English manuscript text at the end.. ¶This remarkable book is one of the most imaginative attempts to add a mechanistic development to the pharmacopeia. The Powder of Sympathy, is the substantive manifestation of Sympathetic magic which is based on the metaphysical belief that like affects like. But with
¶ Digby's 'discovery' of The Powder of Sympathy which facilitates an extra-perceptible connection between a wound and its cause; specifically rapier wounds. Expanding the concepts of healing, and for that matter weapons.
Digby's discovery is depicted in Umberto Eco's novel The island of the day before. Where Dr. Byrd, the scientist on board a lost ship , can tell the time at the ship's port of departure and can then calculate accurately how far they have traveled west. Byrd then uses The Powder of Sympathy, in the attempt to solve the problem of longitude. A dog's wound is kept open on a ship in the South Pacific. At an agreed upon hour the knife that opened that wound is touched in London. The dog howls and whimpers. The seamen then know London time, and from that they can determine longitude.