Dictionarium polygraphicum. Black enamel.

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
The mixture or matter for Enamels in general.
Take leaden bullets thirty pounds, tin in bits thirty three pound; mix them and calcine them, as is directed in the article CALCINATION (which see) searce the calx, put it into a glaz'd earthen pot full of water; set it over a fire, let it boil a little, take it off the fire, decant off the water gently into another vessel, which carries along with it the finest flower of the calx, repeat this till no more flower will rise; then calcine the remaining calx, as you did before.
Put these waters into one large body or vessel, and evaporate to a dryness, over a very gentle fire.

The mixture for Enamels.
Take of this calx twenty five pounds, of fritt of white tars, searced twenty five pounds, fine salt of tartar four ounces; mix all well together in a pot, and let it stand in a glass-house fire furnace, for ten hours to meliorate and purify; then take it out and reduce it to an impalpable powder, which keep close in a dry glass for use.

I. Thus is the matter prepar'd to receive colours for Enamel.
Take of this mixture six pounds, zaffer prepar'd three ounces, manganese prepar'd three ounces, reduc’d to a very fine powder, put them into a glaz'd earthen pot in the furnace for some hours; let the pot be very large, because the metal will swell much; when it is purified, cast it into cold water, and dry it, put it into the pot again to melt and purify; then if the colour is good, keep it for use, if not you must put in more or less of the colouring matter, till it is perfect, and then make it into cakes.

II. Another black Enamel.
Take of the above mention’d mixture six pounds, zaffer prepar'd, Crocus Martis made with vinegar, feretto, of each two ounces, all being reduc’d into a fine powder; mix them well together, put them into a glaz'd earthen pot in a furnace to melt and purify; when it is well digested, cast it into water; then dry it, and put it into the pot again; let it melt and refine, then take it out and make it up into cakes.

III. Another velvet black Enamel, finer and fairer than the former.
Take of the said mixture six pounds, red-tartar fix pounds, manganese prepar'd three ounces, reduce all to a very fine powder; mix them and put them into a very large we glaz'd earthen pot, because the mass will swell; melt and purify, cast it into water, dry it and put it into the pot again, melting and purifying as before; make it up into cakes, and keep it for use.

A black for painting on Enamel.
1. The former black Enamel, levigated with oil of spike, makes an excellent colour.
2. Take black Enamel of either fort, peregrine well calcin'd of each four ounces, mix and make an impalpable powder; then add oil of spike, and it will agree excellently with the Enamel.