Besides, you must also provide your self of red or reddish kind of flints, which (besides iron) do also contain in them a volatile gold. Out of these is the tincture to be extracted by the spirit of salt, or by Aq. Regis; after that manner I delivered at large in the first Century, and in the [Appendix to the fifth part of the prosperity of Germany], and will yet farther teach more clearly and more compendiously in this Century.
These extractions are to be poured upon the lead-ashes, that they may be well moistened therewithall; the unprofitable phlegm is to be evaporated by a gentle heat, and the fire to be augmented that the spirits also may follow; of which more heavy spirits there will be enough remaining in the secret Cementatory Pot, and as much as is sufficient for the due operation upon the lead, that so being bettered it may afterwards prove a gainfull emitter of its gold and silver.
He that has a desire of exercising this labour with greater profit, may satisfie his desire, if he will but pour on such extractions twice or thrice upon the said lead ashes, that they may be con-centrated by them afore they are cemented in the Cementatory Vessel, and may be reduced into the bettered lead. For by this means, all the labours and costs will be more largely recompenced, and the more plenty of gain gotten.
This now is the making the lead-ashes, whether you do either per se, or by the help of the other metals, convert it by Cementation into a better metal.
V. A brief description of the secret Cementatory Pot, which admits not of any spilling, and which is sealed with the Seal of Hermes, of which I made mention in the first Century.
Build with Stones or Clay or Potters earth such a Furnace as that is, which I described in the first part of my Furnaces, as necessary for the making of spirit of salt. But let the lower part thereof be a little broader that so the Metals being cast upon the Coals may not stick to the walls of the Furnace and so be somewhat lost, but may fall directly down on the live Coals. It must be made four square and of such a bigness as may serve the purpose according as you are minded to cement a greater or lesser quantity of metal therein.
VI. Of the Cover of the Cementatory-pot, what it ought to be, that so it may suffer nothing to goe away in fume.
This Cover of this Cementatory Box or Furnace which I told you was to be made of the Lute of Wisedom, is not properly a Cover but a Leaden Cistern, serving for the reception of those spirits which are driven up by the fire out of the Lead-ashes. This Lead receiver is to lie in another Leaden Cistern, which is to be filled with water, and ’tis to be so fitted to a pipe that is to come out of the Furnace, that the ascending spirits passing thereinto may be the better refrigerated by the water, and the sooner condensed, and saved for farther uses.
VII. Of the use and benefit of this secret Cementing Pot.
When any one has a mind to cement the Lead ashes, from which the extractions of the coloured Flints have been sometimes abstracted in the said Cementatory Box, and to graduate them, or so bring to pass that they may contain [or hold the] Gold and Silver, let him first of all fill his Furnace with Charcoal, and let him so order it that his fire may kindle by little and little till the Furnace be well heated red hot; till this is done, the Cover that is at top is to be taken so long off, that so neither the heat nor smoke may pass out at the side through the Pipe into the adjoyned Leaden Cistern.