Roger Bacon - or more probably some one who usurped his name - declared that with a certain amount of the philosopher's stone he could transmute a million times as much base metal into gold, and on Raimon Lull was fathered the boast, " Mare tingerem si mercurius esset."
The plan came to nothing, and next year Becher was again busy at Vienna, trying to transmute Danube sand into gold, and writing his Theses chemicae veritatem transmutationis metallorum evincentes.