John French, holder of degrees from Oxford University (BA 1637, MA 1640), was a Paracelsian physician who practiced his profession with the Parliamentary army during the Civil War. He wrote the popular Art of Distillation; or, a treatise of the choicest spagyricall preparations that appeared in several editions beginning in 1651, and another treatise on medicinal spas in Yorkshire. Besides espousing Paracelsian iatrochemistry, French's works often reveal a strong mystical and millenarian emphasis, along with a bias against the “tyranny” of Aristotle and Galen. French was also a notable translator of alchemical and medical works; we have already seen that A New Light of Alchymie, the Sendivogian work included in this collection, was “faithfully translated out of the Latin into the English tongue. By J. F. M. D.”

Further confirmation of French's belief in the truth of alchemy appears in his brief address “To the Reader,” prefixed to the first edition of John Everard's English translation of The Divine Pymander of Hermes Mercurius Trismegistus, published in 1650. He categorically affirms the authenticity of the translation's original, which can “justly challenge the first place for antiquity, from all the Books in the World, being written some hundreds of yeers before Moses his time.” French's assertion appeared nearly forty years after Isaac Casaubon's correct dating of the Hermetic writings. The text of French's preface is from the 1650 edition of The Divine Pymander.