The Most Secret Rosary of the Philosophers

Therefore, the diversity of things is caused by the diversity of their parts. Recognize, therefore, the clean from the unclean, because nothing gives what it does not have. The clean is of one essence, empty of alterations; the unclean is diverse and gathered from contrary parts, susceptible to easy corruption. The proof of these is clear in the Sun and Saturn, because Saturn is entirely corrupted, but the Sun not at all; and therefore all planets need its light. The knowledge, therefore, of the contrariety of bodies and the principle of their creation makes this magisterium the alchemical work easy; for filth adheres to filth, since they are of the same genus, but the clean overcomes the nature of the unclean, not suffering the defect of mixture. Therefore, do not seek in nature what is not in it. Since things are not made except according to their nature, and the greater corruption is in the passive thing than in the active.

And the tincture the coloring/transformative agent is in the stone the subject of the work, just as the heart is in a human. Therefore, use the nobler and simpler member, and it suffices for you. Yet the member of the heart is from the body, just as the member of the brain is from the head, because in the heart is the power of the irrational soul, just as in the brain is the power...