For conclusion, we are to treat of the manner of projection, which is the accomplishment of the work, the desired and expected joy. The red Elixir turns into a citrine color infinitely, and changes all metals into pure gold. And the white Elixir does infinitely whiten, and brings every metal to perfect whiteness.

“Mirror Of Alchemy” by Roger Bacon, 1250


When the artist would transmute any metal- for instance, lead- let a quantity be melted in a clean crucible, to which let a few grains of gold in filings be cast; and when the whole is melted, let him have in readiness a little of the powder, which will easily scrape off from his “stone,” the quantity inconsiderable, and cast it on the metal while in fusion. Immediately there will arise a thick fume, which carries off with it the impurities contained in the lead, with a crackling noise, and leaves the substance of the lead transmuted into most pure gold, without any kind of sophistication; the small quantity of gold added, previous to projection, serves only as a medium to facilitate the transmutation, and the quantity of your tincture is best ascertained by experience, as its virtue in proportioned to the number of circulations you have given after the first has been completed.

“On The Philosopher’s Stone”


Now the projection is after this manner to be done: put the body, or metal upon the fire in a crucible, and cast thereon the elixir as aforesaid, moving, or stirring it well; and when it is melted, become liquid, and mixed with the body, or with the spirit, remove it from the fire, and you shall have fine gold or silver, according to what you elixir was prepared from.

“Root Of The World” by Roger Bacon, 1250


When you wish to make projection proceed as follows: Take a hundred parts of Mercury, cleansed with vinegar and salt; place it in a crucible over the fire; when it begins to bubble up, add one part of your Elixir, and project the whole upon one hundred other parts of boiling purified Mercury. Then project one part of this entire mixture upon one hundred parts of purified Mercury, and the whole will be turned into our Elixir. Then project one part of this last, coagulated, upon one hundred parts of purified Mercury, and it will become the purest gold, or silver, according as the Tincture is red or white.

“The New Pearl Of Great Price” by Peter Bonus, 1339