The seed and its earth being thus prepared, nothing remains but a judicious conjunction of them together; for it too much moisture prevails, the philosophical egg may burst before it can go through the heat necessary for its hatching. To speak without a figure. Our subject must now be enclosed in a small glass vial, made strong enough to bear a due heat, which is to be raised gradually to the highest degree: the best form for this vessel being that of an oil flask, with a long neck; but these are much too thin in substance for this operation. In such a vessel the mixture is to be sealed hermetically, and digested so long till it is fixed into a dry concretion; but, if, as we observed, the moisture should predominate, there is great danger of the vessel bursting, with a vapor which cannot be concentered by the fixing quality in the matter. The intention is, nevertheless, to fix our subject in the heat, and so render its future destruction impossible.

Your sulphur and mercury being thus united, put them into a glass vial, before described, in such a quantity as to take up one-third of its contents, leaving two-thirds, including the neck, for the circulation of your matter. Secure the neck of your vial with a temporary luting at the first, and give a gentle heat, observing whether it sublimes and fixes alternately. If it easily sublimes and shows a disposition, at intervals, to subside at the bottom of the vessel, all is well conducted hitherto; for the moisture will first be predominant, which the sulphur can only perfectly absorb as the heat is increased for the perfect ripening of our Paradisiacal Fruit. Therefore, if it manifests a too early disposition for fixing, add more of the corrected mercury till Luna rises resplendent in her season; she will give place to the Sun in his turn. This is deservedly called the Great Work of the Philosophers; and the artist having done his part hitherto, must seal up his glass hermetically, an operation which every maker of barometers knows how to perform.

The glass is then to be put into a furnace with a proper nest contrived for its reception, so as to give a continual heat from the first to the fourth degree. A heat of the first degree is sufficient at the first, for some months, in which method much time may be lost by a young practitioner, till he knows how to handle his matter from experience; but then he is not so liable to be disappointed with the bursting of his vessel or the matter vitrifying. Thus you have arrived at the desired seed-time in our Philosophical Work, which, though it may appear in the artist’s power to ripen, depends no less on the Divine blessing than the harvest, which a painful husbandman has not the presumption to expect otherwise than from God’s beneficence.

We shall describe the changes which our subject undergoes during the second part of the process, commonly called the Great Work of the Philosophers. Our vessel being warily heated at the first for fear of its cracking, an ebullition of the contained matter is brought on, so that the moisture is alternately circulated in white fumes above, and condensed below, which may continue for a month or two, nay longer, increasing the heat gradually to another degree, as your matter discovers a disposition for fixing, by the vapor continuing at longer intervals condensed, and rising in a lesser quantity, of an ash color, or other dark shades, which it will assume as a medium to perfect blackness, the first desirable stage in our harvest. Other colors may be exhibited in this part of the work without danger, if they pass transiently; but if a faint redness, like that of the corn poppy, continues, the matter is in danger of vitrifying, either from an impatient urging of the fire, or the moisture not being sufficiently predominant. The whole substance resembles molten pitch, or the aforesaid bituminous substance, bubbling less and less, resting in one entire black substance at the bottom of your glass. This is called the blackness of black, the head of the crow, etc., and is esteemed a desirable stage in our philosophical generation, being the perfect putrefaction of our seed, which will ere long show its vital principle by a glorious manifestation of Seminal Virtue.

“On The Philosopher’s Stone”