Enamels.

Scientific American 23, 26.2.1848

For the Scientific American.

Yellow enamel.
Take four parts of a flux, made of glass of lead one pound, pearl ashes 6 owes, and borax four ounces, and mix with one part of antimony and the same of sulphured of silver, made by putting plates of silver into a crucible with flowers of sulphur and submitting them to a red heat, and afterwards reducing it to powder. These should be mixed and vitsitied together and afterwards levigated (ground fine) with one part of the salts of tin. It is then ready for enamel painting and makes a splendid opaque yellow. If six parts of the above flux be used with calcined silver two puts, and antimony half a part, and fluxed in a proper vessel till all are transparent and atterwardslevigated, it makes a bright transparent yellow and the antimony can be omitted it greater transparency is wanted. If crocus (the sulphate of iron burnt in a crucible) be used instead of the antimony in the foregoing receipt, a very firm and clear cool yellow is the result, one fit for farming some kind of greens; or for a deep dull yellow omit the silver and add antimony, flux until perfectly vitrified and afterwards levigate with one part of the salts of tin, when it will be fit for use. It is a very good and strong yellow, and very cheap.
A yellow enamel verging towards orange, can be made with the above first mentioned flux fused until transparent with one part sf crocus This enamel is valuable for brown mixtures and shading different yellows. Ochre used in fluxing is also a good and cheap subgenee for making yellows. Orpiment is also used for making yellows with the above flux, but it must not receive much heat.

Bright Orange.
Take of ultramarine, or cobalt, and the opaque yellow mixture, first described in this article, each one part, and of the flux first mentioned two parts, and just mix them well together, when they will be ready for painting. If the same flux be used in six parts, to one part of the precipitate of copper from a sulphate by an alkali, and fluxed together until they are transparent, a composition for a fine deep green enamel is the result. It can be made to any shade of lightness by using any quantity necessary of the transparent yellows previously described. If cobalt and a yellow made from crocus mixed with their proper fluxes, be levigated together, they make a fine mixture for a bright transparent enamel green.

If the first mentioned flux six parts, of ochre one part, and copper calcined to a purple color one part, be well fluxed to, her and afterwards ground fine with one plot of the calx of tin, it makes a good composition fur a cheap green. By the greater quantity of cobalt used so are these greens made dark, and light by adding the salts of tin or antimony in greater proportions to the lightness required.

If the precipitate of gold and calcined silver be used with their proper fluxes and mixed together, it makes a splendid bright orange enamel. Antimony used along with these red and yellow coloring substances in different proportions, will make all the different shades of orange.

Copper calcined to redness and red tartar or argil, one part each, with any of the fluxes mentioned, if fused together until they are transparent and no longer, and then levigated with an equal part of the glass of antimony, a very cheap orange composition fur enameling is the result. Transparent purple and opaque purples are made by mixtures of the precipitate of gold along with cobalt or ultramarine and any if the fluxes mentioned. For the transparent purples the coloring matter us first vitrified with the fluxes and afterward levigated for the painting, but for opaque purples the coloring matters are only well mixed with the fluxed at a medium heat and not vitrifled. This is the difference between the two ways, transparent and opaque enamel colors.

Brown Enamels.
By mixing any of the purples mentioned along with bright yellow and a very small portion or manganese and an equal part of calcined tin, a fine brown enamel is the result. They must be levigated for use. According as the browns are wanted on the yellow shade, more yellow is added, and for the red shade more red, for the dark blackish brown more manganese, and for the clear olive use ultramarine and yellow and a small portion of manganese. Light and dark shades can be made by adding a greater or less quantity of the calx of tin for lightness, and of the dark coloring matter for darkness.

Black enamel.
Take of the flux first described six parts, of cobalt one part, of antimony one part, of scarlet ochre and magnesia each a fourth part, mix and fuse them together until they become a black of the deepest cast. If borax be used in a greater quantity, a softer enamel is the result. This composition is good for painting enamel dial plates or painting on china, or enamel grounds, is the manner of prints, or for light or shade, like India ink for water colors. By using with this the greater quantity of borax and arsenic, fine outward touches may be trade on hard enamel grounds, as they will run with but little heat and show the finest shade without any danger of fusing a hard ground that has much flint or Venitian glass in its composition.
The fine colors on china, so dazzling and so truly beautiful, are all made of the foregoing compositions. Great skill is used and much practice required to do them well and touch secrecy observed regarding the business —The source from whence the foregoing information is derived is rarely opened.

- M. K.