THE DOMESTIC COMMONPLACE-BOOK;

Containing authentic Receipts and miscellaneous Information in every Branch of Domestic Economy, and of general Utility.

ON THE COMPOSITION OF ENAMEL; || also altered by coloured enamels: WHITE, PURPLE, RED, YELLOW, so that gold and platina are the GREEN, BLUE, VIOLET, &c. only metals upon which colourTHE beautiful art of enamelinged enamels can be laid without beconsists in the application of a ing altered by them. The enasmooth coating, or vitrified var-meling on earthen ware or porcelain nish, melted upon the substance to forms a different branch of the art. which it is applied, so as to proWhite Enamel. duce a glossy varnish, either transparent or opaque, and with or without colour, figures, or other designs, which are likewise melted on the surface by the action of heat.

The simplest kind of enamel on metals is that fine opaque glass which is applied to the dials of watches: a good enamel of this kind, fit to be applied both to porcelain and metals, should be of a very clear, fine, white colour, so nearly opaque as only to be transparent at the edges; and at a moderate red heat it should run into that kind of paste, or imperfect fusion, which allows it to extend itself freely and uniformly, and to assume a vitreous glossy even surface, without, however, fully melting into a thin liquid. The opaque white colour of this enamel is given by oxide of tin, which possesses, even in a small portion, the capability of rendering vitreous mixtures opaque white. This enamel, either for earthen ware, or the pur

The general principles on which the art of the enameler is founded, are, on the whole, very simple; but there is perhaps none, of all the chemical processes of the arts, which requires a greater practical skill than the art of enameling. The only metals that are enameled upon, are gold, platina, and copper, and with the latter the opaque enamels are only used. Transparent enamels can only be applied to the surface of such metals as do not become oxidated by open exposure to a red heat, nor which suffer a chemical change by the contact of a vitreous fluid abound-poses of being applied on metals, ing with a metallic oxide. Hence is best prepared in the following coloured enamels, upon metals, manner :cannot be applied to silver: though this metal suffer no oxidation by mere heat, yet if, for example, a yellow enamel, made of oxide of lead or antimony, is laid on a surface of polished silver, and kept melted on it for a certain time, the silver and enamel act on each other, and the colour, instead of being a clear yellow, becomes brown. Copper is

Calcine 100 parts of lead with from 15 to 20, 30, or even 40, of tin. A mixture of these metals. calcines very easily when in contact with air. As soon as it is brought to a red heat, it burns like charcoal, and is oxidated very speedily. The composition which calcines best, is that in which the lead is to the tin as 100 to 20 or 25.

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pitate. The solution of tiu must be added gradually, until the purple colour begin to appear; you then stop; and having suffered the

ed, it must be washed by the repeated affusions of soft water, and suffered to dry slowly in a dark place, or defended from light. The different solutions of gold, in whatever manner precipitated, provid

In proportion as the calcination is | tin is sufficient to form this precieffected, the oxidated or calcined part must be taken away, and the operation continued till the whole becomes pulverulent. As some small particles always escape oxi-coloured precipitate to be depositdation, you must expose to the fire a second time the oxide obtained, in order to oxidate it completely, which may be easily known by its ceasing to sparkle. When the proportion of tin exceeds 25 or 30 parts, a stronger fire is necessary to pro-ed the gold be obtained in the duce oxidation. In a word, by varying the degrees of heat, the operator will easily be able to discover the temperature best suited to the mixture on which he ope

state of a purple oxide, always give a purple colour, which will be more beautiful in proportion to the purity of the oxide: the presence of the minutest portion of iron materially injures the colour. The gold precipitated in the form of fulminating gold, which loses the property of fulminating when mixed with fluxes, gives a tolerably good purple. Saline fluxes are better suited for this colour than those in which there are metallic oxides. Those, therefore, which have been made of silex or powdered flint, borax and chalk, or white glass, borax and a little white oxide of antimony, with a minute portion of nitre, may be employed with it. Purple enamel will bear from 4 to 24 parts of flux, and even more, according to the shade required. It is to be remarked, that this colour will not bear a strong heat.

Red Enamel.

We have no substance capable of giving directly a fine red colour. To obtain this colour, it must be compounded different ways. Take

* Some valuable information concerning the general nature and preparation of this precipitate, is to be found in 41, 2, or 2 parts of green sulphate practical Essay on Chemical Re-agents, of iron, and sulphate of alumine, or Tests, p. 156, published by J. Cal- or alum; fuse them together in their low, Crown-court, Princess-street, Soho, water of crystallization, taking care that they are well mixed.

1516.

Continue to heat them to complete
dryness, then increase the fire so as
to bring the mixture to a red heat,
and keep the mixture heated until
it has every where assumed a beau-
tiful red colour, which may be as-
certained by taking out a little of
it, from time to time, and suffering
it to cool in the open air. The
proportions of sulphate of alumine,
or alum, and sulphate of iron, may
be varied. The more alum be add-
ed, the paler will be the colour.
Three parts of alum to 1 of sul-
phate of iron, gives a flesh colour.
It is alum also which gives this co-pure: lay a light coating on the
lour the property of being perma-
nent in the fire. This enamel does
not require much flux; that which
is best suited for it, is composed of
alum, red lead or minium, common
salt, and ground flint: in general,
3 parts of flux, with 1 of the colour;
but this ought to be varied accord-
ing to the shade required.

into a vessel over a fire, sufficient
to sublime the muriate of ammo-
nia; and when the mass has as-
sumed a yellow colour, the opera-
tion is finished. Yellow enamels
require so little flux, that 1 or 2
parts, to 1 of the colour, is in ge-
neral sufficient: saline fluxes are.
improper for them, especially those
which contain nitre. They must
be used with fluxes composed of
flint, oxide of lead, and borax,
without any salt. The best method
of employing the oxide of silver
to produce a yellow, is to use it

Yellow Enamel.

Though this colour may be obtained in a direct manner, compound yellows are preferred, because they are more certain in their effect, and more easily applied, than yellow obtained in a direct manner from the substance which produces it; namely, silver.

The metallic oxides which form the basis of the yellow colour, besides silver, are generally those of lead, such as red lead or minium, white lead, and white oxide of antimony. The following are the different compositions that may be used :-One part of white oxide of antimony, 1, 2, or 3 of white oxide of lead, I of alum, and 1 of muriate of ammonia. When these matters have been pulverized and mixed together, they may be put

place which you wish to stain yellow, and heat the vessel gently, to give it the colour; when it has been sufficiently heated, you take it from the fire, and separate the coating of oxide, which will be in a great measure reduced to a metallic state, and you will find the place which it occupied tinged yellow. This process succeeds best on glass. Sulphate of silver, ground up with water, answers better than muriate of silver, which is commonly employed.

Green Enamel

is obtained directly from oxide of copper. All the oxides of this metal may be employed. They require but little flux, which must not even be too fusible. One part or 2 of flux is sufficient for 1 of oxide. Green may also be produced from a mixture of blue and yellow. Oxide of chrome gives a fine emerald green colour.

Blue Enamel

is obtained from oxide of cobalt: it is, of all enamel colours, the most certain and easily manageable: it is also the most fixed of all colours, and becomes equally

beautiful with a weak as with a strong fire. The more pure the oxide of cobalt, the more beautiful will be the blue. The presence of iron is extremely hostile to this colour, by imparting to it a muddiness. The saline fluxes which contain nitre are those best suited for it; but the flux which, with the cobalt blue, produces the greatest brilliancy and splendour, is that composed of white glass, of glass of borax, and nitre, with a minute portion of antimonial oxide.

Violet Enamel.

of oxide of cobalt improves the colour.

Black Enamel

is produced by a mixture of oxide of cobalt, and black oxide of manganese.

Those who paint on enamel, earthen ware, porcelain, &c. must regulate the fusibility of the colours by the most tender of those employed. For example, the purple: when the degree best suited to purple has been found, the other less fusible colours may be regulated by the addition of flux, when it is necessary to fuse all the colours at the same time, and with the same degree of heat.

This colour is produced by means of black oxide of antimony with saline fluxes. By varying the fluxes, the shade of the colour is The reader may conceive how also varied. It is very fixed so long much the difficulties of this nice as it retains its oxigen: this is, how- art are increased, when the object ever, difficult to fix. No combus-is to paint designs that require extible substance ought to come into treme delicacy of shading, and a contact with it. A minute portion proper selection of colours.

BIOGRAPHICAL SKETCHES AND ANECDOTES.

ANECDOTE OF MARSHAL DE BIRON.

The marshal's revenues were princely, and his style of living magnificent, without prodigality. He was remarkable for doing the honours of his nation to foreigners, to whom his table and his boxes at the theatres were always open. There is a charming anecdote re

THIS nobleman, who, during their beloved commander had lived: many years, was a colonel in the this declaration, though no excuse French guards, was not more dis- for their conduct, was yet a proof 'tinguished for his bravery and mi- of the influence which he had oblitary knowledge, than for the vir- tained over them. tues which adorned his private character; he was adored by his soldiers, who found in him a friend and father, and whose bitter regret for his loss was perhaps a stronger testimony of his virtues than the most laboured panegyric. It is well known, that, during the Revolution, his soldiers frequently en-lated of him and Admiral Rodney, deavoured to excuse the excesses of which they were guilty, by declaring that they never would have abandoned the cause of royalty if

who was detained at Paris for debt when war broke out in 1778. The marshal knew little of the admiral but by reputation, but his brave