The term "cement" includes all those substances employed for the purpose of causing the adhesion of two or more bodies, whether originally separate, or divided by an accidental fracture. As the various substances that may require cementing differ very much in texture, &c., a number of cements possessed of very different properties are required, because a cement that answers admirably under one set of circumstances may be perfectly useless in others. The general principles upon which the success or failure of cementing usually depends are:

The different parts of a solid are held together by an attraction between their several particles, which is termed the attraction of cohesion. This attraction acts only when the particles are in the closest possible contact: even air must not be between them. If, after breaking any substance, we could bring the particles into as close a contact as before, and perfectly exclude the air, they would re-unite, and be as strongly connected as ever. But in general this is impossible: small particles of grit and dust get between them; the film of interposed air cannot be removed; and thus, however firmly we press the edges of a broken cup together, it remains cracked china still.

The cohesion between the particles of the cement is very much less than the adhesion of the cement to other bodies; and if torn apart, the connected joint gives way, not by the loosening of the adhesion, but by the layer of cement splitting down the centre. Hence the important rule that the _less_ cement in a joint the stronger it is. To unite broken substances with a thick cement is disadvantageous, the object being to bring the surfaces as closely together as possible. The general principles that ought always to be borne in mind having been mentioned, the manufacture and uses of some of the more useful cements may be described.

The very useful preparation sold under this title is merely a thin cake of soluble glue, which, when moistened with the tongue, furnishes a ready means of uniting papers, &c. It is made by dissolving one pound of fine glue or gelatine in water, and adding half a pound of brown sugar, boiling the whole until it is sufficiently thick to become solid on cooling; it is then poured into moulds, or on a slab slightly greased, and cut into the required shape when cool. (

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Paste is usually made by rubbing up flour with cold water, and boiling; if a little alum is mixed before boiling it is much improved, being less clammy, working more freely in the brush, and thinner, a less quantity is required, and it is therefore stronger. If required in large quantity, as for papering rooms, it may be made by mixing one quartern of flour, one quarter pound of alum, and a little warm water; when mixed, the requisite quantity of boiling water should be poured on whilst the mixture is being stirred. Paste is only adapted to cementing paper; when used it should spread on one side of the paper, which should then be folded with the pasted side inwards, and allowed to remain a few minutes before being opened and used; this swells the paper, and permits its being mere smoothly and securely attached. If kept for a few days, paste becomes mouldy, and after a short time putrid; this inconveince may be obviated by the use of:

Permanent Paste, made by adding to each half-pint of flour paste without alum, fifteen grains of corrosive sublimate, previously rubbed to powder in a mortar, the whole to be well mixed; this, if prevented from drying, by being kept in a covered pot, remains good any length of time, and is therefore convenient; but unfortunately it is extremely poisonous, though its excessively nauseous taste would prevent its being swallowed accidentally. It possesses the great advantage of not being liable to the attacks of insects.

The liquid glue of the shops is made by dissolving shellac in water, by boiling it along with borax, which possesses the peculiar property of causing the solution of the resinous lac. This preparation is convenient from its cheapness and freedom from smell; but it gives way if exposed to long-continued damp, which that made with naphtha resists.

Of the use of

very little need be said; it should always be prepared in a gluepot or double vessel, to prevent its being burned, which injures it very materially. The chief objection to the use of this contrivance is, that it renders it impossible to heat the glue in the inner vessel to the boiling point; this, however, can be obviated by employing in the outer vessel some liquid which boils at a higher temperature than pure water, such as a saturated solution of salt (made by adding one-third as much salt as water). This boils at 224° Fahr., 12° above the heat of boiling water, and enables the glue in the inner vessel to be heated to a much higher temperature than when pure water is employed. If a saturated solution of nitre is used, the temperature rises still higher.

Soak isinglass in water till it is soft; then dissolve it in the smallest possible quantity of proof spirit, by the aid of a gentle heat; in two ounces of this mixture dissolve ten grains of ammoniacum, and whilst still liquid add half a drachm of mastic, dissolved in three drachms of rectified spirit; stir well together, and put into small bottles for sale.

.— Liquefy the cement by plunging the bottle in hot water, and use it directly. The cement improves the oftener the bottle is thus warmed; it resists the action of water and moisture perfectly.

An excellent cement may be made from rice flour, which is at present used for that purpose in China and Japan. It is only necessary to mix the rice flour intimately with cold water, and gently simmer it over a fire, when it readily forms a delicate and durable cement, not only answering all the purposes of common paste, but admirably adapted for joining together paper, cards, &c., in forming the various beautiful and tasteful ornaments which afford much employment and amusement to the ladies. When made of the consistence of plaster-clay, models, busts, bas-relievos, &c., may be formed of it; and the articles, when dry, are susceptible of high polish, and are very durable.

The white of an egg, well beaten with quicklime, and a small quantity of very old cheese, forms an excellent substitute for cement, when wanted in a hurry, either for broken china or old ornamental glassware.

This cement being nearly colourless, possesses advantages which liquid glue and other cements do not.—Dissolve half an ounce of gum acacia, in a wineglass of boiling water; add plaster of Paris sufficient to form a thick paste, and apply it with a brush, to the parts required to be cemented together.

Lime and Egg Cement is frequently made by moistening the edges to be united with white of egg, dusting on some lime from a piece of muslin, and bringing the edges into contact. A much better mode is to slake some freshly-burned lime with a small quantity of

water; this occasions it to fall into a very fine dry powder, if excess of water has not been added. The white of egg used should be intimately and thoroughly mixed, by beating with an equal bulk of water, and the slaked lime added to the mixture, so as to form a thin paste, which should be used speedily, as it soon sets. This is a valuable cement, possessed of great strength, and capable of withstanding boiling water. Cements made with lime and blood, scraped cheese, or curd, may be regarded as inferior varieties of it.

Cracked vessels of earthenware and glass may often be usefully, though not ornamentally, repaired by white lead spread on strips of calico, and secured with bands of twine.

In point of strength, all ordinary cements yield the palm to Jeffery's Patent Marine Glue, a compound of India-rubber, shellac, and coal-tar naphtha. Small quantities can be purchased at most of the tool warehouses, at cheaper rates than it can be made. The colour of this glue, however, prevents its being much used.

An exceedingly strong, and at the same time a transparent and colourless cement is made by Messrs. Kay Brothers, of Stockport, and is sold by most fancy stationers and chemists under the name of Coaguline. It is easily and quickly applied, and will be found extremely serviceable in repairing glass, china, and stone articles. It is inexpensive.

Red Cement which is employed by instrument makers for cementing glass to metals, and which is very cheap, and exceedingly useful for a variety of purposes, is made by melting five parts of black rosin, one part of yellow wax, and then stirring in gradually one part of red ochre or Venetian red, in fine powder, and previously

. This cement requires to be melted before use, and it adheres better if the objects to which it is applied are warmed.

A soft cement, of a somewhat similar character to that just described, is useful for covering the corks of preserved fruit, and other bottles. It is made by melting yellow wax with an equal quantity of rosin, or of common turpentine (not oil of turpentine, but the resin), using the latter for a very soft cement, and stirring in, as before, some dried Venetian red.

This is employed for making a superior coating to inside walls, but must not be confounded with the

. It is made by mixing twenty parts of well-washed and sifted sharp sand with two parts of litharge and one of freshly burned and slaked quicklime, in fine _dry_ powder. This is made into a putty, by mixing with linseed oil. It sets in a few hours, having the appearance of light stone; and we mention it, as it may be frequently employed with advantage in repairing broken stone-work (as steps), by filling up the missing parts. The employment of Roman cement, plaster, &c., for masonry work, hardly comes within the limits of Domestic Manipulation.

An adhesive material for uniting the parts of boots and shoes, and for the seams of articles of clothing, may be made thus:—Take one pound of gutta-percha, four ounces of India rubber, two ounces of pitch, one ounce of shellac, two ounces of oil. The ingredients are to be melted together, and used hot.

Take any quantity of linseed oil, say half a pint; put it into an old pot, or any vessel that will stand the fire without breaking—the vessel must not be more than one-third full; put it on a slow fire, stir it occasionally until it thickens as much as required; this will be known by cooling the stick in water, and trying it with the fingers. It is best to make it rather harder than for use. Then pour it into cold water. It can be brought back to the consistency required with a little Archangel tar.

This is an elegant and easy domestic art. Take yellow withered leaves, dissolve gum, black paint, copal varnish, &c. Any articles, such as an old tea-caddy, flower-pots, fire-screens, screens of all descriptions, work-boxes, &c., may be ornamented with these simple materials. Select perfect leaves, dry and press them between the leaves of books; rub the surface of the article to be ornamented with fine sand paper, then give it a coat of fine black paint, which should be procured mixed at a colour shop.

When dry rub smooth with pumice-stone, and give two other coats. Dry. Arrange leaves in any manner and variety, according to taste. Gum the leaves on the under side, and press them upon their places. Then dissolve some isinglass in hot water, and brush it over the work. Dry. Give three coats of copal varnish, allowing ample time for each coat to dry. Articles thus ornamented last for years, and are very pleasing.

An excellent imitation of carved oak, suitable for frames, boxes, vases, and ornaments in endless variety, may be made of a description of leather called basil. The art consists in simply cutting out this material in imitation of natural objects, and in impressing upon it by simple tools, either with or without the aid of heat, such marks and characteristics as are necessary to the imitation. The rules given with regard to the imitation of leaves and flowers apply to ornamental leather work. Begin with a simple object, and proceed by degrees to those that are more complicated.

Cut out an ivy or an oak leaf, and impress the veins upon it; then arrange these in groups, and affix them to frames, or otherwise. The tools required are ivory or steel points of various sizes, punches, and tin shapes, such as are used for confectionery. The points may be made out of the handles of old tooth-brushes. Before cutting out the leaves the leather should be well soaked in water, until it is quite pliable. When dry, it will retain the artistic shape. Leaves and stems are fastened together by means of liquid glue, and varnished with any of the drying varnishes, or with sealing-wax dissolved to a suitable consistency in spirits of wine. Wire, cork, gutta-percha, bits of stems of trees, &c., may severally be used to aid in the formation of groups of buds, flowers, seed-vessels, &c.

Mix some lamp-black with sweet oil. With a piece of flannel cover sheets of writing-paper with the mixture; dab the paper dry with a bit of fine linen. When using, put the black side on another sheet of paper, and fasten the corners together with small pins. Lay on the back of the black paper the pattern to be drawn, and go over it with the point of a steel drawing pencil: the black will then leave the impression of the pattern on the undersheet, on which you may draw it with ink.

Patterns on cloth or muslin are drawn with a pen dipped in stone blue, a bit of sugar and a little water; wet to the consistence wanted.

Procure the best white swan or goose feathers; have them plucked off the fowl with care not to break the web; free them from down, except a small quantity on the shaft of the feather. Get also a little fine wire, different sizes; a few skeins of fine floss silks, some good cotton wool or wadding, a reel of No. 4 Moravian cotton, a skein of Indian silk, some starch and gum for pastes, and a pair of small sharp scissors, a few sheets of coloured silk paper, and some water colours.

Having procured two good specimens of the flower you wish to imitate, carefully pull off the petals of one, and, with a piece of tissue paper, cut out the shape of each, taking care to leave the shaft of the feather at least half an inch longer than the petal of the flower. Carefully bend the feather with the thumb and finger to the proper shape; mind not to break the web.

Take a piece of wire six inches long; across the top lay a small piece of cotton wool, turn the wire over it, and wind it round until it is the size of the heart or centre of the flower you are going to imitate. If a single flower, cover it with paste or velvet of the proper colour, and round it must be arranged the stamens; these are made of fine Indian silk, or feathers may be used for this purpose. After the petals have been attached, the silk or feather is dipped into gum, and then into the farina. Place the petals round, one at time, and wind them on with Moravian cotton, No. 4. Arrange them as nearly like the flower you have for a copy as possible. Cut the stems of the feathers even, and then make the calyx of feathers, cut like the pattern or natural flower. For the small flowers the calyx is made with paste. Cover the stems with paper or silk the same as the flowers; the paper must be cut in narrow strips, about a quarter of an inch wide.

Take common white starch and mix it with gum water until it is the substance of thick treacle; colour it with the dyes used for the feathers, and keep it from the air.

Use common ground rice, mixed into a stiff paste with any dye; dry it before the fire, and when quite hard, pound it to a fine powder. The buds, berries, and hearts of some double flowers are made with cotton wool, wound around wire, moulded to the shape with thumb and finger. Smooth it over with gum water, and when dry, cover the buds, berries, or calyx with the proper coloured pastes; they will require one or two coats, and may be shaded with a little paint, and then gummed and left to dry.

Flowers of two or more shades are variegated with water colours, mixed with lemon juice, ultramarine and chrome for blue; and to produce other effects, gold may also be used in powder, mixed with lemon juice and gum water.

Into two pennyworth of oil of vitriol mix two pennyworth of the best indigo in powder; let it stand a day or two; when wanted shake it well, and into a quart of boiling water put one tablespoonful of the liquid. Stir it well, put the feathers in, and let them simmer a few minutes.

Put a tablespoonful of the best turmeric into a quart of boiling water; when well mixed put in the feathers. More or less of the turmeric will give them different shades, and a very small quantity of soda will give them an orange hue.

Mix the indigo liquid with turmeric, and pour boiling water over it; let the feathers simmer in the dye until they have acquired the shade you want them.

Three good pink saucers in a quart of boiling water, with a small quantity of cream of tartar. If a deep colour is required, use four saucers. Let the feathers remain in the dye several hours.

In a quart of boiling water dissolve a teaspoonful of cream of tartar; put in one tablespoonful of prepared cochineal, and then a few drops of muriate of tin. This dye is expensive, and scarlet flowers are best made with the plumage of the red ibis, which can generally be had of a bird-fancier or bird-stuffer, who will give directions how it should be applied.

About two teaspoonfuls of cudbear into about a quart of boiling water; let it simmer a few minutes before you put in the feathers. A small quantity of cream of tartar turns the colour from lilac to amethyst.

The feathers must be put into hot water, and allowed to drain before they are put into the dyes. After they are taken out of the dye, rinse them two or three times in clear cold water (except the red, which must only be done once), then lay them on a tray, over which a cloth has been spread, before a good fire; when they begin to dry and unfold, draw each feather gently between your thumb and finger, until it regains its proper shape.

These are made of green feathers, cut like those of the natural flower, and serrated at the edge with a very small pair of scissors. For the calyx of a moss-rose the down is left on the feather, and is a very good representation of the moss on the natural flower.

There is no art more easily acquired, nor more encouraging in its immediate results, than that of modelling flowers and fruit in wax. The art, however, is attended by this draw-back—that the materials required are somewhat expensive.

The appliances required for commencing the making of waxen flowers will cost from 20s. to 30s., and may be obtained at most fancy repositories in large towns. Persons wishing to commence the art would do well to inquire for particulars, and see specimens of materials; because in this, as in every other pursuit, there are novelties and improvements being introduced, which no book can give an idea of.

Petals and leaves of wax flowers are made of sheets of coloured wax, which may be purchased in packets of assorted colours.

The stems are made of wire of suitable thicknesses, covered with silk, and overlaid with wax; and the leaves are frequently made by thin sheets of wax pressed upon leaves of embossed calico. Leaves of various descriptions are to be obtained of the persons who sell the materials for wax flower making.

Ladies will often find among their discarded artificial flowers, leaves and buds that will serve as the base of their wax models.

The best guide to the construction of a flower—far better than printed diagrams or patterns—is to take a flower, say a

, a

, or a

. If possible, procure

flowers, nearly alike; and carefully pick one of them to pieces; lay the petals down in the order in which they are taken from the flower, and then cut paper patterns from them, and number them from the centre of the flower, that you may know their relative positions.

The perfect flower will guide you in getting the wax petals together, and will enable you to give, not only to each petal but to the

of the flower, the characteristics which are natural to it. In most cases, they are merely pressed together and held in their places by the adhesiveness of the wax. From the paper patterns the wax petals or other portions of the flowers may be cut. They should be cut singly, and the scissors should be frequently dipped into water, to prevent the wax adhering to the blades.