The Holy Guide

John Heydon (1629 - 1667 or 1670) was an English Rosicrucian, alchemist, and attorney. He published more than ten books during the last twelve years of his life. In this work is a chapter called "Chemical Dictionary," which contains a useful set of definitions of various terms used in Alchemy. That chapter includes much excellent advice for students of Alchemy, such as, "Try not at first experiments of great cost, or great difficulty, for it will be a great discouragement to thee, and thou ...