"He strongly maintained the virtues of aurum potabile (liquid gold), and wrote a book entitled Medicinae Chymicae et Veri Potabilis Auri Assertio (1610). Another tract, De Lapide philosophorum et Lapide Rebis, related to the older alchemy. ...[I]n alchemical symbolism "Rebis" was the name given to the hermaphrodite figure representing the union of the great philosophical principles, sulphur and mercury, in the operation of making the philosopher's stone..."