In the same treatise Basil Valentine describes spirit of salt which he had obtained by the action of oil of vitriol on marine salt; brandy, distilled from wine; and how to get copper from pyrites by first obtaining a sulphate, then precipitating the metal by plunging into the solution a blade of iron. This operation was a favourite evidence with later alchemists of the transmutation of iron into copper.
According to some of his biographers Basil Valentine was born in 1393; others are judiciously vague and variously suggest the twelfth, thirteenth, or fourteenth century. That he was a Benedictine monk, he tells us himself, and several monasteries of the order have been named where he is supposed to have lived and laboured.
Many medical historians have doubted whether such a person as Basil Valentine ever existed. His writings are said to have been circulated in manuscript, but no one has ever pretended to have seen one of those manuscripts, and the earliest known edition of any of Basil Valentine's works was published about 1601, by Johann Thölde, a chemist, and part owner of salt works at Frankenhausen in Thuringia. It is rather a large claim on our credulity, or incredulity, to assume that Thölde was himself the author of the works attributed to the old monk, and that he devised the entire fiction of the alleged discoveries, chemistry and all. It was not an uncommon thing among the alchemists and other writers of the middle ages to represent their books as the works of someone of acknowledged fame, just as the more ancient theologians were wont to credit one of the apostles or venerated fathers with their inventions. But it was not common for a discoverer to hide himself behind a fictitious sage whose existence he had himself
