Collectanea Chemica, ed. by A.E. Waite, [1893], at sacred-texts.com
A Further Description of the Process.
WHEN the putrefaction of our seed has been thus completed, the fire may be increased till glorious colours appear, which the Sons of Art have called Cauda Pavonis, or the Peacock's Tail. These colours come and go, as heat is administered approaching to the third degree, till all is of a beautiful green, and as it ripens assumes a perfect whiteness, which is the White Tincture, transmuting the inferior metals into silver, and very powerful as a medicine. But as the artist well knows it is capable of a higher concoction; he goes on increasing his fire till it assumes a yellow, then an orange or citron colour; and then boldly gives a heat of the fourth degree, till it acquires a redness like blood taken from a sound person, which is a manifest sign of its thorough concoction and fitness for the uses intended.