I am constrained to believe that there is the Stone which makes Gold, and which makes Silver; because I have at distinct turns, made projection with my hand, of one grain of the Powder, upon some thousand grains of hot Quick-silver; and the business succeeded in the Fire, even as Books do promise; a Circle of many people standing together with a tickling Admiration of us all... He who first gave me. the Gold-making Powder, had likewise also, at least as much of it, as might be sufficient tor changing two hundred thousand Pounds of Gold... For he gave me perhaps half a grain of that Powder, k and nine ounces and three quarters of Quick-silver were thereby transchanged: But that Gold, a strange man, being a Friend of one evening's acquaintance, gave me.
Some decades later the Dutch physician Helvetius told an almost identical yarn about a mysterious "Artist Elias" who gave him a grain of the Stone (which looked like yellow glass) wherewith he turned three ounces of lead to gold, but who went off on a pilgrimage to Palestine and was never seen again. As this tale occurs again and again with little variation, it was evidently borrowed by one biographer from another to pad his narrative. The mysterious stranger with the Stone, we can infer, never existed, and men like van Helmont can have fine reputations for honesty and still draw a long bow.