Dictionarium polygraphicum. Emerald (colours)

Dictionarium Polygraphicum:
Or, The Whole Body of Arts Regularly Digested.
Vol I.
London: Printed for C. Hitch and C. Davis in Pater-noster Row, and S. Austen in St. Paul's Church Yard. MDCCXXXV.
1735
To make a paste for an oriental emerald.
It is shewn elsewhere under the article GLASS of LEAD. The way of tinging crystal and glas of lead of a very fair Emerald colour, or to make a stone that shall imitate a true natural gem, which may be us'd in rings or otherwise.

There are divers sorts of Emeralds, but at present they are all distinguish'd into oriental and occidental; the oriental ones are the harder of the two, and the occidental less so.

To imitate them there are several ways as follows:

Take two ounces of natural Crystal prepar'd as directed, and four ounces of common minium or red lead, powdered and searc'd, and forty-eight grains of verdegrease well pounded and of a good colour, with eight grains of crocus martis prepar’d with vinegar. See the article CRYSTAL.

Mix the whole well together, and put it into a good crucible that will resist the fire, leaving an inch of it empty.

Then cover the crucible with an earthen cover, lute it well, Het it be dried, and then put it into the hottest place of a potter's furnace, where they bake their earthen vessels, and let it stand as long as their pots.

When it is grown cold, break the crucible, and you will find within a matter of the colour of a very fine Emerald; which if set in gold, will surpass in beauty the true oriental Emerald.

If it happens that your matter is not enough refined and purified, you must set it in again the second time into the same furnace, where it will be purified as much as it need to be; which may be known by lifting up the cover, if the matter appears shining.

If it is not so, lute the cover on again, and put the whole into the furnace.

You may observe this once for all, that you must not break the crucible, before the matter is thoroughly bak'd and purisy’d; for if you do, and so are oblig'd to put the matter into another crucible, the paste will be painted and full of blisters.

If you cannot easily have the conveniency of using a potter's furnace, you may make one your self with a little charge, wherein you may put twenty crucibles at once, each of different colours; so one baking may serve for a great deal of matter.

You must make use of hard wood to dry and heat the furnace, as is also directed in the baking of glass, and continue the fire twenty-four hours, in which time the matters ought to be bak'd and purified enough; but for more surety, you may continue the fire six hours longer, and they will be certainly bak’d enough.

The matter being thus rightly bak’d, you may have it polish'd at the wheel, and set it in a foil in gold, as is done with true gems, and you will have an emerald brighter than the oriental.


Another deeper EMERALD colour.
That which makes Emerald deeper than the precedent, proceeds stom the smaller quantity of crystal employ'd in it, with more of the other materials, which make it indeed more fair; but at the same time more brittle.
You must bake it at least fix hours longer than the preceding, to take away that imperfection, which lead usually gives.
The dose of this paste is, one ounce of natural crystal prepared, six ounces and a half of red-lead, seventy-five grains of verdegrease, ten grains of crocus martis made with vinegar; the whole pulveriz'd and well mixt together. Then proceed as directed in the article preceding; only let the matter stand lon ger in the fire, and you will have an admirable oriental Emerald colour, which being set in gold with a foil of the same metal underneath, will be inexpressibly fair.


Another way to make a fairer paste for EMERALDS.
This paste will be as brittle as the preceding for the reasons before given; for you must take seven ounces of minium, to two ounces of natural crystal prepar'd; to which add full eighteen grains of verdegrease, ten grains of crocus martis; the whole pulveriz'd and well mix’d.
Then proceed as directed before, and you will have an Emerald fit for all small works; but not so hard as the former, by reason of the great quantity of lead in it. Therefore it ought to be kept longer in the fire, that the pale colour of the lead may vanish.


Another fairer paste for EMERALDS.
The colour of this paste will surpass the others in beauty, if there be care taken in the operation.
Take two ounces of natural crystal prepar’d, six ounces of minium in powder, and eight grains of verdegrease also in powder; mix the whole well together; then put them into a large crucible, cover'd and well luted, and set it in the furnace as before directed, and do all as directed in the first article, and you will have an extraordinary fair Emerald colour.


Another very fair EMERALD colour.
This stone will be far harder and finer than the preceding.
To make it, take four ounces of natural crystal prepar’d, a quarter of an ounce of red-lead, and the same quantity of verdegrease; pulverize the whole, and sift it fine; put them together into a crucible well clos'd and luted in the furnace, as before directed, letting it stand there for thirty-six hours.
After which, if you will, you may cast your melted matter into a marble mould heated, putting it near the fire to cool gently, and you will have a very fine Emerald.


Another way of making a fair EMERALD.
Take two ounces of crystal, add to it forty-eight grains of crocus martis, and two ounces and forty-eight grains of pure salt of tartar prepar'd; the whole reduc’d into fine powder in a brass mortar; put these into a crucible covered with another, lute them well together; then set it into a glass-house fire, and bake it for twenty-four hours, and then in the annealing furnace for twelve hours, that the matter may cool by little and little, which then take out of the crucible, and you may cut and polish, and you will have a perfect Emerald.


Another oriental EMERALD.
Take ten ounces of the prepar'd matter call'd saturnus glorificatus, (which see in letter s) and natural crystal half an ounce, half an ounce of prepar’d verdegrease, half a dram of feretto of Spain also prepar'd: reduce all into fine powder; mix them well together; put them into a crucible covered with another; lute it, and let it dry; then set it in a glass-house furnace for three days, and afterwards in the annealing furnace for twelve hours. Then break the crucible, and you'll find the matter ting'd of a very fine oriental Emerald colour, which cut and polish.


To make glas of lead of a fair EMERALD colour.
The easiness of tinging glass of lead of any colour is the reason of giving it an excellent Emerald green, especially because green is also natural to it.
Take twenty pounds of crystal fritt powdered and searced, and fixteen pounds of calx of lead also sisted; mix them well together; then put them by little and little into a pot heated in a furnace, and in eight or ten hours time it will be melted; then cast the melted matter into water, and earefully take the remaining lees from it; then put the matter after it is dry’d in the same pot again, and in seven or eight hours time it will be melted again.
Repeat this of casting the melted matter into the water, and feparating the lead that sticks to the pot, as before; then this glass will be cleansed and purified from all the foulness and unctuosity the calx and powder would leave in it, and be very resplendent.
You must put it again into the pot, where it will melt and purify again in a little time.
When it is melted, put to it six ounces of scales of copper thrice calcin'd in powder, with twenty-four grains of crocus martis, made with vinegar, also in powder, and mix them together.
This powder must be cast in at six times, always mixing the glass well, and taking at each time an interval of time, as long as while you may repeat over the creed: let it rest for one hour, and then stir it again, and examine if the colour be to your mind; if it be, let it stand eight hours, that the whole may well incorporate.
Then stir it well, and let it rest a little, that the feces may precipitate to the bottom of the pot; then it may be wrought, and the colour can scarce be distinguished from true Emerald.


Another way of making a fairer EMERALD.
For this colour, which will be far fairer than the former, you must change one ingredient in the foregoing, and instead of scales of copper thrice calcin'd, put the same dose of caput mortuum of vitriolum veneris prepar’d; then proceed exactly as before directed and you will have a very excellent green.


To make a green EMERALD colour in glass.
Take common glass well purified from its salt without manganese; put it into a pot in the furnace, and when it is well melted and purified, add to it (as for example) to the proportion of an ounce and half of crocus martis, calcin'd with vinegar to fifty pounds of glass. Mix well the glass at the same time to make it incorporate with the crocus; then let it stand an hour, that it may thoroughly take the colour.
This way nothing will come out yellowish, and it will loose that foulness and blueness, which the common metal always has, and it will become green.
Then add to the same dose fifty pounds of glass, one pound of scales of copper thrice calin'd, and put it in at six divers times, mixing it well each time with the glass, and let it stand two hours to imbibe the tincture.
After the two hours are expir’d, stir it again, and see if it be as you would have it; if the colour be too blue, you must add to it some crocus martis prepar’d, and you will have a very fine Emerald colour.


Another EMERALD green fairer than the preceding.
The more pure the matter is, the finer the work will be that is made with it.

Take crystal fritt without manganese, which has been twice wash’d in water, to take out all the salt, and put it in a pot in the furnace; then add to it half the quantity of common white metal, also without manganese.

These two matters being well melted, mix’d and purified, put to fity pound of metal, a pound and a quarter of powder of copper plates thrice calcin'd, prepar'd with one ounce of crocus martis calcin’d and reverberated with sulphur.

After you have mix’d them well together, then put in those powders at six different times, stirring well the matter each time, observing what has been said in the preceding.

You may make the colour lighter or deeper as you please, adding crocus martis, if it be too blue; and calcin'd powder of Venus, if it be not enough so, and so you will have from this a Burnet green.


Another wonderful green.
Altho' this colour is admirable, yet it is only made of common glass made with pulverine, and without manganese.
This being well melted and purified, you must put in equal parts of powder of scales of copper thrice calcin'd, and scales of iron which fall from the smith's forge or anvil, without any other preparation than well washing them, to cleanse them from ashes and coals that mingle with them; afterwards dry them well, and pound them as fine as you can, and searce them. These scales serve instead of cracus martis.
You must observe the doses and way of proceeding, as has been before directed as to Emerald colours.
These scales of iron will give an admirable green; and they will drive out all the dull, natural green, which is in common glass, and make it become yellowish, or will give it a yellow green, very bright and fair.


Another oriental EMERALD green, finer than the rest.
Put four pounds of common fritt of pulverine, five pounds of common white glass pulveriz'd, five pounds of crystal fritt well wash'd; add to these three pounds of minium, mix them all together, and in a little time they will be pretty well purified.
Afterwards cast all that metal into water to purify it more, taking care that no part of the lead sink to the bottom of the pot wherein it is cast, for it will break it, if speedy care be not taken to take up again what is precipitated.
This glass being thus wash'd and afterwards dry'd, ought to be put into the pot again, to be melted and purified for the space of a day; then you must add to it a little of the caput mortuum of vitriol of Venus, without corrosive, (see VITRIOL) with a little crocus martis, stirring the metal, and proceeding, as has been shewn in the preceding process.
Then you will have an admirable oriental Emerald green, which may be wrought as you please.