Following came various enthusiasts, such as Raymond, the ephemeral (died 1315), who flared like a meteor into his brief, brilliant career; Arnold de Villanova (1240), a celebrated adept, whose books were burned by the Inquisition on account of the heresy they taught; Nicholas Flamel, of France (1350), loved by the people for his charities, the wonder of his age (our age will not admit the facts) on account of the vast fortune he amassed without visible means or income, outside of alchemical lore; Johannes de Rupecissus, a man of such remarkable daring that he even (1357) reprimanded Pope Innocent VI., for which he was promptly imprisoned; Basil Valentine (1410), the author of many works, and the man who introduced antimony (antimonaches) into medicine; Isaac of Holland who, with his son, skillfully made artificial gems that could not be distinguished from the natural; Bernard Trevison (born 1406), who spent $30,000 in the study of alchemy, out of much of which he was cheated by cruel alchemic pretenders, for even in that day there were plenty of rogues to counterfeit a good thing. Under stress of his strong alchemic convictions, Thomas Dalton placed his head on the block by order of the virtuous (?) and conservative Thomas Herbert, 'squire to King Edward; Jacob Bohme (born 1575), the sweet, pure spirit of Christian mysticism, "The Voice of Heaven," than whom none stood higher in true alchemy, was a Christian, alchemist, theosophist; Robert Boyle, a conspicuous alchemical philosopher, in 1662 published his "Defense of the Doctrine touching the Spring and Weight of the Air," and illustrated his arguments by a series of ingenious and beautiful experiments, that stand to-day so high in the estimation of scientific men, that his remarks are copied verbatim by our highest authorities, and his apparatus is the best yet devised for the purpose. Boyle's "Law" was evolved and carefully defined fourteen years before Mariotte's "Discours de la Nature de l'Air" appeared, which did not, however, prevent French and German scientific men from giving the credit to Mariotte, and they still follow the false teacher who boldly pirated not only Boyle's ideas, but stole his apparatus.