Theatrum chemicum, praecipuos selectorum auctorum tractatus de chemiae et lapidis philosophici antiquitate, veritate, iure, praestantia, & operationibus, continens: in gratiam verae chemiae, et medicinae chemicae studiosorum ... congestum, et in sex partes seu volumina digestum; singulis voluminibus, suo auctorum et librorum catalogo primis pagellis: rerum vero & verborum indice postremis annexo. Volumen primum [- sextum]

Which that Hermes Trismegistus calls true without falsehood, certain, and most true: and which Plato, Eustathius, Suidas, Solinus, Strabo, Pliny, and many others prove, and which Geber asserts to be a gift of the highest, blessed, sublime, and glorious God. By whose wonderful art that Royal powder is composed, or fusible salt, oil, or non-burning sulphur of nature, earth of the philosophers, Elixir, potable gold, or the Water of life of the philosophers, tincture, precious stone—Indus or Indicus, or philosophical—or Medicine, which performs wonderful actions on the three genera of things: animal, vegetable, and mineral, as will be explained to you more fully in the third chapter. For that reason, the ancient philosophers said that the stone is animal, vegetable, and mineral.

Hence Arnaldus in the Rosary: "Alchemy is one hidden part of natural philosophy, necessary beyond other parts: from which one art is constituted, to which there is no equal. For by it, imperfect precious stones are perfected; the sick human body is restored to health; and imperfect metals are transmuted into gold and silver, by one certain medicinal, universal body, to which all particularities of medicine are reduced and infused."

Alber. on Minerals, lib. 3, chap. 9. those who whiten with white, and yellow with yellow, etc. On sophists and impostors.

But may God, the greatest and best, grant that you do not perniciously fall into the hands and snares of those impostors who miserably waste their effort on useless, or perhaps forbidden, things, such as white or red sophistic tinctures, augmentations, multiplications, and extractions of gold (as they falsely speak), knowingly and maliciously deceiving the common people everywhere, to whom they promise much, or golden mountains. For they consume their own wealth and that of others in various and vain sophistic labors; they pass their age and wear out their whole life in false, dangerous, harmful, and sophistic studies of practice and a thousand impostures, some of whom pursue drinks, others fortunes, others luxuries, others honors, others the most disgraceful lusts. Whence that true, natural, rare, hidden, and divine Chemical art sometimes has a bad reputation among many, indeed it is considered an illusion and mere deception. You should account those rascals, sycophants, impostors, and sophists as nothing, you should spurn them, and keep them far from your mind, for they are certainly not worthy of the title of Chemical philosophers: rather, you should embrace and unfold sincere or proven Chemical books and philosophy itself for a long time, much, and anxiously, not for the sake of profit or glory:

Geber. lib. 1, chap. 7.

And you should admire that sublime Chemistry, sent down from heaven by the Father of lights, and be consecrated to it, favor it, and pray well for it. For that art is preserved in divine power, and He bestows it upon whom He wills, and withdraws it, He who is glorious and sublime, and filled with all justice and goodness. To whom thanks are always to be given, and praises to be sung, for His ineffable goodness,