The art of glass shewing how to make all sorts of glass, crystal and enamel : likewise the making of pearls, precious stones, china and looking-glasses : to which is added, the method of painting on glass and enameling : also how to extract the colours from minerals, metals, herbs and flowers ... : illustrated with proper sculptures / written originally in French, by Mr. H. Blancourt, and now first translated into English ; with an appendix, containing exact instructions for making glass-eyes of all colours.

CHAP. CL. A Turcoise-blue Enamel.

THIS Colour of the Turcois, or Turkey-stone, is very fine for Enamel, but withal very diffi∣cult to make well, and requires a great deal of Experience. Now 'tis sufficiently known, that Pra∣ctice will at length make the most uneasie Begin∣ners Masters of their Trade, therefore we must not be discouraged if we fail in our first Tryals, be∣cause by continuing to repeat them, we shall at length be sure to perform well: 'Tis always sup∣posed you understand your Undertaking, and are sufficiently qualified to distinguish when you are in the right or wrong, or you can never hope to suc∣ceed. For this cause we ought not to stand dozing on every Unsuccess, for Nature, which never fails, will still be ready to inform us, provided we have Judgment enough to determine her Precepts.

Though we have taken occasion from the Turcois, to make this Digression here, it may nevertheless be a convenient enough Consideration in Cases of a subli∣mer Nature, even in all the Undertakings of Man. Since we are so naturally apt to be impatient and di∣sturbed

if we can't effect those Matters in (as it were) a moment of Time, which Nature it self takes a whole Age to perform: And this is what mostly arrests the Accomplishments of our greatest Designs, and imposes on us a seeming Impossibility in the most easie things: Thus Obscurity interposes in the brightest Essays of the Sun, and we can't en∣joy one day, though never so serene and fair, that is not more or less over-shadowed with Clouds.

Thus far I have made my Attempt on this Thought, which I hope the Learned will freely par∣don, because I have discoursed nothing but Truth, and what they already are much more familiar with, and satisfied of. But now for our Enamel, which to make of this Turcois 〈◊〉〈◊〉 you must put of our prepared Powder, Chap. CXL••••••••. six pound, into a white glazed Pot to melt and purifie it; then cast it into Water, and when dry put it again into the Pot, and being melted over again, add to it at four times, this Composition, Scales of Copper thrice calcin'd, as in Chap. XXXIV. three Ounces of prepa∣red Zaffer, eighty six Grains of 〈◊〉〈◊〉, prepared as in Book I. forty eight Grains, all these mixt and reduced into a very fine Powder, stir the Matter ve∣ry well each time with your Iron Hook, that the Powders may incorporate, and for Reasons by us given elsewhere before.

Thus when your Matter is fully and well tinged, take the Approbation of a Goldsmith on some of it, as to the Colour, that you may have the more assurance before you proceed to empty your Pot. Your own Experience must shew you how to pro∣portion the Ingredients for tinging the Matter more or less. If you perceive that the Tinging-powders are too predominant, add the more principal prepa∣red Powder; if it be too faint, add the greater quantity of the Tinging-powders: And thus do to improve

or lessen the Colour until it be compleat or to Satisfaction.