(b. St. Nicolas-de-Port, Lorraine, ca. 1547; d. Vaucouleurs, France, ca. 1620)
Little is known of Guibert’s family and early life. A Catholic, he studied medicine at the University of Perugia and, after receiving his degree, traveled in Italy, France, Germany, and Spain. During this period, Guibert became well known as an alchemist, working for several important persons, including Francesco de’ Medici, grand duke of Tuscany, and Cardinal Granvelle, viceroy of Naples and a leader of Philip II’s Spanish faction at Rome. He also associated for a time with Giambattista della Porta in Naples. Settling in the Italian town of Casteldurante, Guibert established a successful medical practice and in 1578 was appointed chief medical authority of one of the papal states. He held this position until leaving Italy at the end of 1579 to work as alchemist for Otto Truchsess, archbishop of Augsburg, whom he advised to commission a translation of Paracelsus’ complete works into Latin.
Guibert’s growing frustration with alchemical pursuits, however, accentuated his dissatisfaction with the obscurity and pretensions of much of sixteenth-century alchemy, and he emerged finally as a vehement critic of the profession. His first published attack came in 1603. In Alchymia ratione et experientia ita demum viriliter impugnata et expugnata, Guibert attempted to refute the major alchemical literature by demonstrating that alchemy is false and that most important alchemical treatises are of no authority. He branded the Tabula smaragdina and other alchemical writings attributed to Ibn-Sīnā, Albertus Magnus, and Thomas Aquinas as spurious. Moreover, the works whose authorship he accepted as genuine, such as the writings of Arnald of Villanova, Roger Bacon, Agrippa, and Paracelsus (the “limb of Satan”), were condemned by him as quackery and heresy. Despite its often exaggerated tone and unsubstantiated claims concerning the literature, Guibert’s Alchymia did serve to reinforce several significant, albeit not widely held, ideas. Most important was his demonstration that metals are distinct species and not transmutable; he rejected the common argument for the transmutation of metals based on analogy to the organic realm—such as the change from larva to butterfly—and contradicted the influential belief that iron can be changed into copper.
His attack on the fundamental tenets of alchemy elicited a vigorous response from Andreas Libavius, the famous German iatrochemist, whose Defensio alchymiae transmutatoriae opposita Nicolai Guiberti (Ursel, 1604) defends the apparent conversion of metals—as in iron-copper replacement reactions—as genuine transmutations. Libavius further asserted that the growth and change of plants and animals afforded a valid analogy for maintaining the reality of chemical transmutations. Guibert, in turn, attacked Libavius’ position in detail in his second major work, De interitu alchymiae (1614). The controversy concerning alchemy was part of the broader debate, which persisted throughout the sixteenth and seventeenth centuries, on the relations between occult science, natural magic, and emerging modern science. Guibert’s rejection of alchemy derived from his revulsion from the activities of those charlatans who styled themselves scientists; from an orthodox Catholic suspicion of heresy in Renaissance Neoplatonism and the Hermetic revival of the sixteenth century; and, finally, from a recognition of certain theoretical and experimental inconsistencies of alchemy.
I. Original Works. Guibert’s scientific works include Assertio de murrhinis, sive de iis quae murrhino nomine exprimuntur (Frankfurt, 1597); Alchymia ratione et experientia ita demum viriliter impugnata et expugnata (Strasbourg, 1603); and De interitu alchymiae metallorum transmutatoriae tractatus aliquot. Adiuncta est eiusdem apologia in sophistam Libavium, alchymiae refutatae furentem calumniatorem (Toul, 1614).
II. Secondary Literature. Information on Guibert’s life and work may be found in Dom Calmet, Contenant la bibliothéque Lorraine vol. IV of Histoire de Lorraine (Nancy, 1751), 454–455; and F. Hoefer. ed., Nouvelle biographie générale, XXII (Paris, 1858), 518. The most reliable assessment of Guibert’s scientific work is Lynn Thorndike. A History of Magic and Experimental Science (New York, 1941), V, 648, and VI, 244–247, 451–452. See also James R. Partington. A History of Chemistry (London. 1961). II, 268.