Enameling

“ Then when you want to apply your enamels, having put a morsel of each colour on your palette (the finger palette I described to you above fixed on to the stem of your leaden pear) you mix with every bit of enamel you lay on your work, a tiny drop of this quince-seed-water, the effect of which is to produce a kind of gum which holds the enamels together so that they don’t fall, & no other gum has a like effect. ”

“ Of the many decorative arts, enamelling is one of the most beautiful, having a singular charm of limpid or opalescent colour of great purity, richness and durability, and being capable of a most refined and varied treatment for the enrichment of metals.
Enamel is a vitreous or glass compound, translucent, semi-translucent or opaque, owing its colouring properties to mineral oxides, or sulphides, a fine opaque white being produced by oxide of tin. These enamels require different degrees of heat in order to fuse them and to cause their adhesion to the metal. ”

“ Enamel is coloured white by oxide of tin, blue by oxide of cobalt, red by gold, and green by copper. Different kinds of enamel are (1) inlaid or incrusted. (2) Transparent, showing designs on the metal under it. (3) Painted as a complete picture. “Many fine specimens of ancient Chinese enamel were seen in the Exhibition of 1851. They have the enamel on copper, beautifully coloured and enlivened with figures of flowers, birds, and other animals. The colouring is most chaste and effective. ”

“ To make enamel. Enamel is thus made: take lead, and melt it, continually taking off the pellicle which floats on the surface, until the whole of the lead is wasted away; of which take one part, and of the powder here- after mentioned, as much; and this is the said powder: take small white pebbles which are found in streams, and pound them into most subtle powder; and if you wish to have yellow enamel, add oil of filberts and stir with a hazle rod; for green, add filings of copper, or verdigris ”

“ A highly polished enamel is passed through the fire a number of times in the process of painting; otherwise it would be impossible to imitate any great delicacy of tint—as the colors are considerably changed by burning. "As the plates are every time subjected to a high red heat, it is obvious that enamels must be the most durable of all kinds of paintings." At an enamel factory for lining metal vessels with a porcelain coating, I saw a woman who has been employed for four years to mix enamel in the consistency of buckwheat dough, and pour it into vessels to form an enamel lining. ”

“ STONING After a piece of enamel has been fired, it is often found that too much enamel has been used, that is, that the enamel may have run over the edge of the part to be enameled, or it may not present a smooth surface but instead consist of a series of humps, or, especially in the case of transparent enamels, it may be on in such layers that the color is deepened or even lost entirely. ”

“ Plique-à-jour enamel is similar to cloisonné except that the wires are soldered to each other without any background, thus forming a sort of filigree, the spaces within which, when filled with enamel, somewhat resemble a stained-glass window.
In enamel painting a picture is painted on the enamel. Usually white opaque enamel is used for the background, and the painting is executed with finely ground enamel or china paints, after which it is covered with a layer of transparent enamel which serves as a protection for the painting. ”

“ The method of laying a white upon the enamel ground is a matter of individual taste, so far as the medium is concerned. By some, pure distilled water is preferred to any other liquid for mixing the enamel. ”

“ Disposition to caries shows itself even in the developing tooth in the composition of its enamel, which is undulating, whereas teeth with quite smooth enamel have much greater power of resistance. The enamel appears to be the only tissue in the body which is subject to no metabolism, and which remains quite unchanged. Every alteration in it which is caused by external influences, and every defect of the enamel, remains during the whole of life, and can never be repaired. Dentine also shows differences in structure as regards its disposition to caries. ”

“ Great care is required in compounding dentifrices and mouth-waters, and special attention must be paid to the correct selection of the material. The substances used must be chemically pure, and no caustic or sharp or grating materials, such as pumice, sand, ossa sepiæ, etc., should be employed, they destroying the enamel of the teeth.
The coloring substances used to give the dentifrices and mouth-waters a pleasing appearance should under no condition be injurious or poisonous, such as, for instance, brilliant rosa, cinnabar, aniline, chrome yellow, picric acid, etc. ”

“ And when all the preliminary work is carefully done, and all the interstices nicely filled with the coloured enamels, you put the whole thing in the furnace, in order to make the enamel flow. To begin with you must only subject it to a slight heat, after which, when you have filled up any little openings with a second coat of enamel you may put it in again under a rather bigger fire, & if it appear after this that there are still crannies to be filled up, you put it to as strong a fire as the craft allows and as your enamels will bear. ”

“ We will confine our attention to what is known as hard enamel in contradistinction to japans, lacquers, and enamel paints, which are often called soft enamels. Hard enamels are compounds of glass with different metallic oxides which produce the different colors. ”

“ Metals are the usual foundations to which enamels are applied, but stone, earthenware, and glass may be enamelled. When one speaks of “an enamel” we understand it to mean a metal that is ornamented by a vitreous decoration fused and fixed to the metal surface by heat. There are three principal kinds of enamels: the “embedded or encrusted,” the “translucent upon relief,” and the “painted.” Some enamelled objects have a mixture of two methods.
The embedded or so-called encrusted kind has two varieties, which are best known under their French names, the Cloisonné and the Champlevé. ”

“ In the manufacture of the substance enamel a much greater advance has been made, for whereas the colours, and consequently the schemes of colour, were extremely limited, we now possess an infinite gradation in the colours, as well as the transparency and opacity, the hardness and softness of enamels. There are only two colours which cannot yet be obtained; these are opaque vermilion and lemon yellow in a vitrified state. Many of the colours we now employ were not known by enamellers such as Léonard Limosin. ”

“ If for some reason a piece has been enameled wrong, so that it is desirable to take the enamel off the metal, this can best be done by leaving the piece for a few hours in a solution of hydrofluoric acid which will eat the enamel, so that it can easily be brushed off the metal, leaving it bright. ”

“ The first step in the formation of the teeth is a continuous invagination of the epithelium covering the jaw to form a deepish wall of tissue running in the thickness of the jaw; this is perfectly continuous from end to end of the lower jaw. From this "common enamel germ" (Schmelzleiste of the Germans [23] ) "special enamel germs" (Schmelzorgane, enamel organs) are developed here and there as thickenings in the form of buds which arise on the outer side of the fold of epithelium and some way above its lower termination. ”

“ If the silver is not “fire-stained,” red enamel will often become maroon when fired, and fondant and other delicate colors will become streaked or spotted. If the fire-staining and dipping have not been carefully done, the enamel is likely to chip out, have pit-holes in it, or contain black blotches.
As the acid fumes eat the flesh quite rapidly, it is advisable to wear rubber gloves when dipping the metals.
14 CHAPTER III
CHARGING Enamel is “charged,” or put on the metal, in the form of a watery mud, by means of a small spatula. ”

“ Enamel, Yellow. Superior yellow enamels are less easily produced than those of most other colours; they require very little flux, and that mostly of a metallic nature. The following come highly recommended by experienced artists:—
Prep. 1. From ‘frit’ or ‘flux,’ fused with oxide of lead, and a little red oxide of iron.
2. Lead, tin, ashes, litharge, antimony, and sand, of each 1 oz.; nitre, 4 oz.; mix, fuse, and powder; and add the product to ‘flux’ or ‘frit,’ q. s.
3. White oxide of antimony, alum, and sal-ammoniac, of each 1 part; pure carbonate of lead, 1 to 3 parts, or q. s. ”

“ The scalpriform incisors of the rodents, already alluded to, have the enamel band on the front face of the tooth; the softer dentine behind wears away more rapidly, keeping the cutting surface bevelled, like the edge of a chisel, while the hard enamel forms the sharp edge. In some instances the enamel is absent altogether and the teeth are composed entirely of dentine, as in the elephant tusk. ”

“ Enamel may be applied to metal objects and add a great deal to their value and attractiveness if used sparingly. The enamels most used are transparent and opaque; the transparent reflects the color of the metal adding a great deal of life to the work, the opaque gives color on the surface only. ”

“ In preparing the ground for enamel painting, there are two things which have been essentially considered in all times and countries. The enamel ground Page 95 must be more fusible than the metal on which it is placed, or else both would melt together. Also the enamel with which the final decoration is executed must be more easily made fluid than the harder enamel on which it is laid. In fact, each coat must of necessity be a trifle more fusible than the preceding one. A very accurate knowledge is necessary to execute such a work, as will be readily understood. ”

“ The teeth are composed of very hard bone and enamel. The latter is a substance exceeding in density any other in the body. It covers the crown of the teeth, and is thickest in those parts which are most exposed to forcible contact in mastication; but, in no place, is it more than the twelfth of an inch in thickness.
10. The most common disease of the teeth is caries, or decay, and almost every part of them is liable to be affected by it, but especially the sides of those in front, and the crowns of those on other parts of the jaws. ”

“ The enamel, thick on the top of the crown, grows thinner towards the root, an arrangement required by its use, which is to defend the tooth, to support principally the efforts of mastication, which are made especially upon the top of the crown. ”

“ The tooth pushes thru the gum; and as it goes by, the cells at the sides of the pocket and on top plaster it with a coating of enamel. Therefore, as most of us find out to our cost, this enamel once destroyed, can never grow again. Once clear of the pocket where it was formed, it has to last us the rest of our lives; and little boys and girls who don’t keep their teeth clean when they are young, have to put up with something not nearly so good when they are grown up. ”

“ The enamel of the teeth is formed once for all during childhood. The substance of the teeth is mineral, chiefly lime. It will therefore be appreciated that the child needs abundance of mineral in order that he may have sound tooth material. This he can get only from mineral in his food (see page 169) , or, before his birth, from his mother’s diet. Good circulation in the jaws is also essential for normal development both for teeth and jaws, therefore the importance of some hard food every day after ten months. ”

“ WONDERFUL STARCH ENAMEL.
For polishing shirt bosoms, collars, cuffs, lace curtains, etc., putting on the same gloss and hard pearl finish as when bought at the store new. Every lady should use the wonderful enamel for the following reasons: It enables an ordinary ironer to compete with any laundry; it makes the clothes clear and white; it makes clothes iron smoothly, and prevents the [203] iron sticking; it makes old linen look like new; and it saves a woman many hours' hard work each week. It is easily made, and five cents' worth will last an ordinary family six months. ”

“ They act in the following manner:—The spirit, being very liquid or thin in its nature, wets the enamel and passes by it when it rises in the stalk, so that the elevation of temperature does not affect its position, but when the spirit sinks down it drags the enamel with it, thus registering the lowest temperature, so that the distance the enamel is found down the stalk indicates how low the spirit may have descended in any particular time, say a night. ”

“ Then a deep groove is made in the middle of the upper teeth, crossing them all, and itself cutting through at least one-fourth of the whole thickness of the teeth, so that the enamel is cut quite through, a fact which we Europeans, who are taught by our dentifricators that any damage done to the enamel is mortal to the tooth, find it difficult to believe. ”

“ Haviland & Co., who may be taken as a standard, classify their faïences into six groups—viz. cream faïences, which are thus named from their color, and which are decorated with paintings under the enamel or with translucid enamels; enamelled paintings, possessing all the tone, richness and variety of oil-paintings; grand-fire fresco paintings, or exact representations of wall frescoes, and especially adapted for panels or architectural ornaments; gilt enamels, reproducing Chinese lac-paintings or vases of precious stones; Limoges enamels, very similar to the ancient enamels of Léonard Limousin ”