Colours to be observed in the Great Work

This is contained in Aurifontina Chymica: or, a collection of fourteen small treatises concerning the first matter of philosophers, for the discovery of their (hitherto so much concealed) Mercury. Which many have studiously endeavoured to hide, but these to make manifest, for the benefit of Mankind in general. London, 1680.
Colours to be observed in the
Operation of the Great Work.
YOU must expect to have it exceeding Black, within 40 days after you have put your Composition into the Glass over the Fire; if it be not black, proceed no further, for it is unrecoverable: it must be as black as the Ravens Head, and must continue a long time, and not utterly to lose it during five months.
If it be Orange colour, or half Red, within some small time after you have begun your Work, without doubt your Fire is too hot; for these are tokens that you have burnt the Radical humour and vivacity of the Stone.
Know ye not, that you may have Black or anything mixed or compounded together with moisture: But you must have Black which must come and proceed of Perfect Metalline Bodies, by a real Putrefaction, and to continue a long time.
As for the colours of Blew and Yellow, they signifie that the Solution and Putrefaction is not yet perfectly finished, and that the colours of our Mercury are not yet well mingled with the rest.
The Black aforesaid is an evident sign, that in the beginning the Matter and Composition doth begin to purge it self, and to dissolve into small Powder, less than the Motes in the Sun; or a glutinous Water, which feeling the heat, will ascend and descend in the Glass: at length it will thicken and congeal, and become like Pitch, exceeding Black; in the end it will become a Body, and Earth, which some call Terra foetida; for then by reason of the perfect Putrefaction, it will have a scent or stink like unto Graves newly opened, wherein the Bodies are not thorowly consumed. Hermes doth call it Terra foliis, but the proper name is Leton, which must be blanched and made white.
This blackness doth manifest a Conjunction of the Male and Female, or rather of the four Elements.
Orange colour then doth shew that the Body hath not yet had sufficient digestion, and that the humidity (whereof the colours of Black, Blew, and Azure do come) is but half overcome by the dryness.
When dryness doth predominate, then all will be white Powder: It first beginneth to whiten round about the outward sides of the Glass; the Ludus Philosophorum doth say, that the first sign of perfect whiteness, is the appearing of a little hoary circle passing upon the Head, shewing it self round about the Matter on the outward sides of the Glass, in a kind of Citrine colour.