V ■ r , ^ S ■■ " n*» THE SCHOOL OF USEFUL ARTS: Containing upwards of 300 RECEIPTS HOUSE PAINTING. VARNISHING, CEMENTING, DYEING, WOOD STAINING, INK MAKING, i STAIN REMOVING, AND MISCELLANIES. GILDING, SILVERING, TINNING, BRONZING, SOLDERING, LACQUERING, JAPANNING, LONDON : PRINTED BY AND FOR WILLIAM COLE, No. 10, NEWGATE-STREET. Price One Shilling* - • -'• > rr’* ‘ 4 -,< • tv-' ;■, THE SCHOOL OF USEFUL ARTS. 4 - GILDING. Gilding is the application of gold to the surface of bodies. Wood, leather, paper, and similar substances, are gilt by fastening on leaves of gold by means of cement or varnish ; but metals are gilded by a chemical application of the gold to the surface. This last is called Water Gilding, The gilding of wood, and similar substances, is of three kinds : — Oil Gilding^ Burnuhed Gilding^ and Japan- ners* Gilding; which we shall severally describe, after noticing the materials and tools necessary for this kind of work. Pure Gold Leaf is made by hammering gold between the leaves of a book made of skins, till they are suf- ficiently thin. Pale Leaf Gold has a greenish colour, and is made of gold alloyed with silver. Dutch Gold is brought from Holland, and is in fact only copper-leaf, coloured by the fumes of zinc. It is much cheaper than true leaf-gold, and is very useful, where large quantities of gilding are wanting, which can be defended from the weather, and where great nicety is not required ; but it changes its colour entirely when ex- posed to moisture ; and indeed, in all cases, its beauty is soon impaired, unless well secured by varnish. A 2 4 THE SCHOOL OF USEFUL ARTS. TOOLS, &C. FOR GILDING. Tlic first itislnimeui is the cushiony for receiving the It aves of gold from the books in which they are bought. It is made by covering a board of about eight inches square, with a double thickness of flannel, and over that a piece of bufl' leather, and fastening it tight round the edges. The knife y for cutting the leaves into the requisite sizes, should be made like a palette knife, and should not have its edge too sharp. The tip is a tool made by fastening the long hairs of a squirrel’s tail between two cards, and is used for taking up the gold leaf after it is cut, and applying it to the article to be gilded. A fitch pencil is used for the same purpose as the last, in taking up very small bits of gold leaf. A hall of cotton is neceesary for pressing down the leaf, after it is laid on. A large cameVs hair-brush is used for dusting the work, and clearing away the superfluous gold. An afjute burnisher is used for rubbing the gold, after it is laid on. OIL GILDING. Virst, prime the work with boiled linseed-oil and white lead -j and when that is dry, do it over with a thin coat of gold size, made of stone ochre ground in fat oil. When that is so dry as to feel clammy to the fingers, or to be, as the gilders call it, tachey, it is fit for gilding. Having spread the leaves upon the cushion, cut them into slips of the proper size for covering the work j then breathe upon the tip, which will cause it to take up the leaves from the cushion. Having applied them by the tip on the proper parts of the work, press them down by the ball of cotton. Observe to repair, by putting small pieces of gold on any parts which you have omitted to cover. When all the work is sufficiently covered, let it dry, and clean it off* with the brush. This sort of gilding is the easiest, least expensive, and stands the weather best, ami may be cleaned with a little water at any time j but wants the lustre of burnish gilding. THE SCHOOL OF USEFUL ARTS. 5 Burnished Gilding . — This is the sort of gilding gene^ rally used for picture-frames^ looking-glasses, &c. The wood intended to be gilt iii this manner, should first be well sized, and then done over with seven or eight coats of size and whiting, so as to cover it with a body of considerable thickness. Having got a sufficient quantity of whiting upon the work, it must be carefully cleaned off, taking care to free all the cavities and hol- lows from the whiting that may have choked them up, and by proper moulds and tools restoring the sharpness of the mouldings intended to be shewn. It is then to receive a coat of size, which is made by boiling Armenian bole with parchment size. This must also remain till it is sufficiently dry for the gold. It must not be quite dry, therefore it would not be prudent to lay on more at a time than can be gilt before it becomes too dry. The work being thus prepared, place it a little de- clining from you, and having ready a cup of clean water, and some hair pencils, moisten a part of the work, and then apply the gold by the tip to the moistened part. The gold will immediately adhere close to the work : pro- ceed to wet the next part, and apply the gold as before, repeating this operation till the whole is completed ; taking care not to let any drops of water come upon any part of the gold already laid on. Care should therefore be taken, that no part be missed in going over it at first, as it is not so easily mended as the oil gilding. The work being thus gilt, it is suffered to remain about twenty-four hours ^ when the parts that are designed to be burnished are polished with a dog’s tooth, or what is better, with an agate burnisher. The gilding must not be quite dry when it is burnished : there is a state proper for the purpose, which is only to be known by experience. Japanners* Gilding . — The gilding of japanned work consists in drawing with a hair pencil, in gold size, the intended ornaments, and afterwards applying gold leaf or gold powder. The gold size may be prepared in the following manner : — ^Take of linseed oil and of gum elemi four ounces ; set the oil to boil in a proper vessel, and then add gum elemi 6 THE SCHOOL OF USEFUL ARTS. gradually in powder, stirring each quantity about in the oil till it appear to be dissolved, and then putting in another, till the whole be mixed with oil. Let the mix- ture continue to boil, fill, on taking a small quantity out, it appear of a thicker consistence than tar, and then strain the whole through a coarse cloth, and keep it for use ; but it must, when applied, be mixed with vermillion and oil of turpentine. Having laid on the gold size, and suffered it to dry, the gold leaf is applied in the usual way; or if it is not wanted to shine so much, gold powder is applied, which is made by grinding gold leaf upon a slope with honey, and afterwards washing the honey away with water. If the gilding is to be varnished over, Dutch gold may be used, or aurum musivum may be used instead of real gold powder. To write on Paper with Letters of Gold. — Put some gum arabic into common writing ink, and write with it in the usual way. When the writing is dry, breathe on it ; the warmth and moisture softens the gum, and will cause it to fasten on the gold leaf, which may be laid on in the usual way, and the superfluous part brushed off ; or, instead of this, japanners’ size may be used. To gild Earthen-ware, or Glass. — With japanners’ gold size draw the design upon the vessel to be gilt, moistening the gold size, as you find necessary, with oil of turpentine. Set the work in a clean place to dry, fur about half an hour, and then place it so near the fire. Chat you can but just bear the heat of it w ith the hand for a few seconds. Let it remain there till it feels ipiite clammy ; then, having procured a cushion, and some leaf gold, cut it into slips of the proper size, and lay it on with a little cotton wool. When the gold is all on, l>ut the ware into an oven to be baked for two or three hours. Glasses, &c. may be gilt, by drawing the figures with shell gold, mixed with gum arabic and a little borax. Ihtn apply sufficient heat to it, and lastly, burnish it. To gihlon Glass or Porcelain, by burning-in. — Dissolve gold lu aqua regia, and evaporate the acid by heat ; you will obtain a gold powder 3 or precipitate the gold fiom THE SCHOOL OF USEFUL ARTS. 7 fhc solution by pieces of copper. Lay this gold on with a strong solution of borax and gum water, and it will be ready for burning-in. To gild Metals , — One method of applying gold upon metals, is by first cleaning the metal to be gilt; then gold leaf is laid on it, which, by means of rubbing with a polished bloodstone, and a certain degree of heat, are made to adhere perfectly well. In this manner silver leaf is fixed and burnished upon brass, in the making of what j is called French plate ; and sometimes also gold leaf is burnished upon copper and iron. Gilding hy Amalgamation , — This is by previously forming the gold into a paste, or amalgam, with mercury. In order to obtain an amalgam of gold and mercury, the gold is first to be reduced into thin plates or grains, which are heated red-hot, and thrown into mercury previously heated, till it begins to smoke. Upon stirring the mercury with an iron rod, the gold totally disappears. The proportion of mercury to gold is generally as six or eight to one. The method of gilding by amalgamation is chiefly used for gilding copper, or an allc^ of copper wdth a small portion of zi :c, which more readily receives the amalgam, and is also preferable on account of its colour, which more resembles that of gold than the colour of copper. When the metal to be gilt is wrought or chased, it ought to be previously covered w'ith quicksilver before the amalgam is applied, that this may be easier spread ; but when the surface of the metal is plain, the amalgam may be directly applied to it. The metal required to be gilt is first rubbed over with a little aquafortis, by which the surface is cleaned from any rust or tarnish that might prevent the union of the two metals. The amalgam being then equally spread over the surface by means of a brush, the mercury is evaporated by a heat just sufficient for that purpose; for if it be too great, part of the gold may also be expelled, and part of it will run together, and leave some of the surface of the metal bare. While the mercury is evapo- rating, the piece is to be from time to time taken from the fire, that it may be examined ; that the amalgam may 8 THE SCHOOL OF USEFUL ARTS. be spread more equally by means of a brush 5 that any defective parts of it may be again covered, and that the heat may not be too suddenly applied to it. When the mercury is evaporated, which is known by the surface becoming entirely of a dull yellow colour, the metal must then undergo other operations, by which the fine gold colour is given to it. First, the gilded piece of metal is rubbed with a scratch^ brush (which is a brush composed of brass-wire,) till its surface is made smooth 5 then it is covered over with a composition, called gilding waofy and is again exposed to the fire till the wax be burnt off. This wax is composed of bees-wax, mixed with some of the following sub- stances : — red ochre, verdigris, copper scales, alum, vitriol, borax ; but, according to Dr. Lewis, the saline substances are sufficient. By this operation the colour of the gilding is heightened ; and this effect seems to be produced by a perfect dissipa- tion of some mercury remaining after the former ope- ration. The gilt surface is then covered over with a saline com- position, consisting of nitre, alum, or other vitriolic salt, ground together, and mixed up into a paste with water or urine. The piece of metal thus covered is exposed to a certain degree of heat, and then quenched in water. By this method its colour is further improved, and brought nearer to that of gold. This effect seems to be produced by the acid of nitre (which is disengaged by the sulphuric acid of the alum, during the exposure to heat) acting upon any particles of copper which may happen to lie upon the gilded surface. Lastly, some artists think that they give an additional lustre to their gilt work, by dipping it in a liquor pre- pared by boiling some yellow materials, as sulphur, or piment, or turmeric. The only advantage of this opera- tion is, that part of the yellow matter remains in some of the hollows of the carved work, in which the gilding is apt to be more imperfect, and to which it gives a rich and solid appearance. THE SCHOOL OF USEFUL ARTS. 9 GILDING IRON OR STEEL. A solution of blue vitriol is applied with a cameVs- hair pencil to the parts of the steel intended to be gilt. By a chemical action, exactly similar to what we have described as taking place when a solution of nitrate of mercury is employed, a thin coating of copper is pre- cipitated on the metal. Copper having an affinity for mercury, a kind of union may by this means be effected between the amalgam and the iron or steel, as the case may be. In whichever of these ways the amalgam is brought into union with the steel, the surface is injured by the action of the acid employed, and still a heat suffi- cient to volatilize the mercury must be afterwards used. To gild Iron by Heat , — When the surface is polished bright, it must be heated till it becomes blue. Gold leaf is then applied to its surface, and burnished down. It is then heated again, and another layer of gold burnished on it. In this manner three or four coats are given, accord- ing to the strength of the gilding intended. This is a more laborious process than the tw^o last, but it is not attended with so much risk. Ethereal gilding on Iron or Steel . — ^The first part of the process consists in pouring over a solution of gold in nitro-muriatic acid (aqua regia) about twice as much ether, which must be done with caution, and in a large vessel. These liquids must then be shaken together ; as soon as the mixture is at rest, the ether will be seen to separate itself from the nitro-muriatic acid, and to float on the surface. The nitro-muriatic acid becomes more transparent, and the ether darker, than they were before ; the reason of which is, that the ether has taken the gold from the acid. The whole mixture is then to be poured into a glass funnel, the lower aperture of which is small 5 but this aperture must not be opened till the fluids have completely separated themselves from each other. It is then to be opened ; by which means the liquid which has taken the lowest place by its greater gravity, viz. the nitro-muriatic acid, will run off ; after which the aper- ture is to be shut, and the funnel will then be found to contain nothing but ether mixed with fhe gold, which is 10 THE SCHOOL OF USEFUL ARTS. to be put into well-closed bottles, and preserved for use. In order to gild iron or steel, the metal must first be well polished with the finest emery> or rather with the finest crocus martis or colcothar of vitriol, and common brandy. The auriferous pther is then to be applied with a small brush ; the ether soon evaporates, and the gold remains on the surface of the metaL The metal may then be put into the fire, and afterwards polished. By means of this auriferous ether, all kinds of figures may be delineated on iron, by employing a pen, or fine brush. It is in this manner that the Sohlinger sabre blades are gilded. Instead of ether, the essential oils may be used, such as oil of turpentine, or oil of lavender, which will also take gold from its solution. To gild Silver , — Dissolve gold in the nitro-muriatic acid, and dip some linen rags in the solution ; then burn them, and carefully preserve the ashes, which will be very black, and heavier than common. When any thing is to be gilded, it must be previously well burnished; a piece of cork is then to be dipped, first into a solution of salt in water, and afterwards into the black powder ; and the piece, after being rubbed with it, must be burnished. This powder is frequently used for gilding delicate articles of silver. To gild Brass or Copper . — Fine instruments of brass, in order that their surface may be kept longer clean, may be gilded in the following manner Provide a saturated solution of gold, and having evaporated it to the con- sistence of oil, suffer it to shoot into crystals. These crystals must then be dissolved in pure water, and the articles to be gilded being immersed in it, are then to be washed in pure water, and afterwards burnished. This process may be repeated several times, till the articles are well gilt. A solution of gold crystals is preferred to a mere solution of gold, because, in the latter, there is always a portion of free acid, which will not fail to exer- cise more or less action on the surface of the brass or copper, and injure its polish. Grecian Gilding . — Dissolve some mercury in muriatic acid (spirits of salt), which will give a muriate of mer- cury. Mix equal parts of this and sal ammoniac, and THE SCHOOL OF USEFUL ARTS. 11 ture chills this kind of varnish, and prevents its taking proper hold of the substance on which it is laid. When the work is so prepared, by the priming with the composition of size and whiting above described, the proper japan ground must be laid on. This is much the best formed of shell-lac varnish, and the colour desired, except while, which requires a peculiar treatment. If brightness be wanted, other means must be pursued. The colours used with the shelUlac varnish may be any pigments whatever, which give the tint of the ground desired. As metals never require to be undercoated with whiting, they may be treated in the same manner as wood or leather. White Japan Grounds . — To form a ground perfectly white, and of the first degree of hardness, remains hitherto a desideratum in the art of japanning, as there are no substances which form a very hard varnish, but which have too much colour not to injure the whiteness, when laid on with a due thickness over the work. The nearest approach, however, to a perfect white var- nish, already known, is made by the following composition : Take flake white, or white lead, washed over and ground up with one-sixth of its weight of starch, and then dried, and temper it properly for spreading with mastic varnish. Lay these on the ground to be japanned, prepared either with or without the under coat of whiting, in the manner above ordered ; and then varnish it over with five or six coals of the following varnish : — Provide any quantity of the best seed-lac, and pick out of it all the clearest and whitest grains, reserving the more coloured and fouler parts for the coarse varnishes, such as that used for priming or preparing wood or leather. Take of this picked lac two ounces, and of gum elemi three ounces, and dissolve them, being previously reduced to a gross powder, in about a quart of spirits of wine, and strain off the clear varnish. The seed-lac will give a slight tinge to this composition, but it cannot be omitted where the varnish is wanted to be hard; though, when a softer will answer the end, the 22 THE SCHOOL OF USEFUL AUTS. proportion may be diminished, and a little crude turpen- tine added to the gum elemi to take oft' the brittleness. Blue Japan Grounds . — But japan grounds may be formed of bright Prussian blue, or of verditer, glazed over by Prussian blue or smalt. The colour may be best mixed with shell-lac varnish, and brought to a polishing state by five or six coats of varnish of seed-lac ; but the varnish, nevertheless, will somewhat injure the colour, by giving to a true blue a cast of green, and fouling, in some degree, a warm blue by the yellow it contains ; where, therefore, a bright blue is required, and a less degree of hardness can be dispensed with, the method before directed in the case of white grounds must be pursued. Red Japan Grounds . — For a scarlet japan ground Vermillion may be used 5 but the vermillion has a glaring effect, that renders it much less beautiful than the crimson produced by glazing it over with carmine or fine lake, or even with rose pink, which has a very good effect used for this purpose. For a very bright crimson, nevertheless^ instead of glazing with carmine, the Indian lake should be used, dissolved in the spirit of which the varnish is compounded, which it readily admits of when good; and in this case, instead of glazing with the shell-lac varnish, the upper or polishing coats need only be used, as they will equally receive and convey the tinge of the Indian lake, which may be actually dissolved by spirits of wine ; and this will be found a much cheaper method than by using carmine. If, however, the highest degree of bright- ness is required, the white varnish must be used. Yellow Japan Grounds . — For bright yellow grounds, King^s yellow, chromate of lead, or turbith mineral, should be employed, either alone or mixed with fine Dutch pink ; and the eft'ect may be still more heightened by dis- solving powdered turmeric root in the spirits of wine, of which the upper or polishing coat is made, which spirits of wine must be strained off from the dregs before the seed-lac be added to it, to form the varnish. The seed-lac varnish is not equally injurious here, or with greens, as is the case with other colours; because, being only tinged with a reddish yellow, it is little more than an addition to the force of the colours. THE SCHOOL OF USEFUL ARTS. 23 Yellow grounds may be likewise formed of Dutch pink only, which, when good, will not he wanting in bright- ness, though extremely cheap. Green Japan Grounds, — Green grounds may be pro- duced by mixing King's yellow and bright Prussian blue, or rather turbith mineral and Prussian blue. And a cheap, but fouler kind of verdigj-is, with a little of the above- mentioned yellows or Dutch pink. But where a very bright green is wanted, the crystals of verdigris, called distilled verdigris, should be employed ; and to heighten the effect, they should be laid on a ground of leaf>gold, which renders the colour extremely brilliant and pleasing. Orange Japan Grounds, — Orange coloured japan grouiKls may be formed by mixing vermillion, or red lead, with King’s yellow or Dutch pink, chromate of lead, or the orange lake, which will make a brighter orange ground than can be produced by any mixture. Purple Japan Grounds. — Purple .Japan grounds may be produced by the mixture of lake and Prussian-blue; of a darker kind, by vermillion and Prussian-blue. They may be treated as the rest with respect to the varnish. Black Japan Ground without Heat. — Black grounds may be formed by ivory black or lamp black j the former is preferable wdien perfectly good. These may always be laid on with shelLlac varnish; and have their upper or polishing coats of common seed-lac varnish, as the tinge or foulness of the varnish can here be no injury. Black Japan Grounds on Iron or Copper ^ by Heat . — For forming the black japan grounds by means of beat, the piece of w'ork to be japanned must be painted over >vith drying oil, and a little lamp black ; and when it is of a moderate dryness, must be exposed to such a degree of heat as will change the oil to black, without burning, so as to destroy or weaken its tenacity. The stove should not be too hot when the work is put into it, nor the heat increased too fast, either of which errors would make it blister ; but the slower the heat is augmented, and the longer it is continued, provided it be restrained within the due degree, the harder will be the coat of japan. This kind of varnish requires no polish, having received, when properly managed, a sufficient one from the heat. 24 THE SCHOOL OF USEFUL ARTS. Tortoise Shell Japan Ground^ hy Heat , — ^Tlie best kind of tortoise shell ground produced by heat is not less valu- able for its great hardness, and enduring to be made hotter than boiling water without damage, than for its beautiful appearance. It is to be made by means of a varnish prepared in the following manner : Take of good linseed-oil one gallon, and of umber half a pound ; boil them together till the oil become very brown and thick ; strain it through a coarse cloth, and set it again to boil ; in which state it must be continued till it acquire a pitchy consistence, when it will be fit for use. Having thus prepared the varnish, clean w’ell the iron or copper plate, or other pieces which are to be japanned, and lay Vermillion tempered with shell-lac varnish, or with drying oil diluted with oil of turpentine, very thinly, on the places intended to imitate the more transparent parts of the tortoise shell. When the vermillion is dry, brush over the whole with the black varnish, tempered to a true consistence with oil of turpentine; and when it is set and firm, put the work into a stove, where it may undergo a very strong heat, and must be continued a considerable time : if even three weeks or a month, it will be the better. This was given amongst other receipts byKunckel; but appears to have been neglected till it was revived with great success in the Birmingham manufactures, where it was not only the ground of snuff-boxes, dressing- boxes, and other such lesser pieces, but of those beautiful tea trays, which have been so justly esteemed and ad- mired in several parts of Europe, where they have been sent. This ground may be decorated with painting and gilding, in the same manner as any other varnished sur- face, which had best be done after it has been duly hardened by the hot stove ; but it would be best to give a second annealing with a more gentle heat, after it is finished. Method of painting Japan Work * — ^Japan work ought properly to be painted with colours in varnish ; though, for the greater dispatch, and in some very nice work in small, for the freer use of the pencil, the colours are sometimes tempered in oil,— which should previously have a fourth part of its weight of gum elemi dissolved in it; THE SCHOOL OF USEFUL ARTS. 25 or ill default of that, gum-sandarac or gum-mastic. When the oil is thus used, it should be well diluted with oil of turpentine, that the colours may lay more evenly and thin; by which means, fewer of the polishing or upper coats of varnish become necessary. In some instances, water colours are laid on grounds of gold, in the manner of other paintings; and are best when so used in their proper appearance, without any varnish over them ; and they are also sometimes so managed as to have the effect of embossed work. The colours employed in this way for painting are best pre- pared by means of isinglass size, corrected by honey or sugar candy. The body on which the embossed work is raised, need not, however, be tinged with the exterior colour, but may be best formed of very strong gum-water, thickened to a proper consistence by Armenian bole and whiting in equal parts ; which being laid on the proper figure, and repaired when dry, may be then painted with the proper colours, tempered with the isinglass size, or in the usual manner, with shell-lac varnish. Manner of varnishing Japan Work . — The finishing of japan work lies in the laying on and polishing the outer coats of varnish, which are necessary as well in the pieces that have only one simple ground of colour, as with those that are painted. This is in general done best with com- mon seed-lac varnish, except in the instances, and on those occasions, where we have already shewn other methods to be more expedient; and the same reasons w hich decide as to the fitness or impropriety of the var- nishes, with respect to the colours of the ground, hold equally w'ith regard to those of the painting. For where brightness is the most material point, and a tinge of yellow will injure it, seed-lac must give way to the whiter gums ; but where hardness and a greater tenacity are most essential, it must be adhered to ; and where both are so necessary, that it is proper one should give way to the other in a certain degree reciprocally, a mixed varnish must be adopted This mixed varnish should be made of the picked seed- lac. The common seed-lac varnish, which is the most useful preparation of the kind hitherto invented, may be thus made c 26 THE SCHOOL OF USEFUL ARTS. Take of seed-lac three ounces, and put it into water, to free it frona the sticks and filth that are frequently intermixed with it 5 and which must be done by stirring it about, and then pouring off the water, and adding fresh quantities, in order to repeat the operation, till it be freed from all impurities, as is very effectually done by this means. Dry it then, and powder it grossly, and put it, with a pint of rectified spirits of wine, into a bottle, of which it will not fill above two thirds. Shake the mixture well together, and place the bottle in a gentle heat, till the seed-lac appears to be dissolved; the shaking being in the mean time repeated as often as may be con- venient , and then pour off all that can be obtained clear by this method, and strain the remainder through a coarse cloth. The varnish thus prepared must be kept for use in a bottle well stopped. The manner of using the seed-lac or white varnish is the same, except with regard to the substance used in polishing ; which, where a pure white of a great clearness of other colours is in question, should be itself white ; whereas the browner sorts of polishing-dust, as being cheaper, and doing the business with greater dispatch, may be used in other cases. The pieces of work to be varnished should be placed near a fire, or in a room where there is a stove, and made perfectly dry ; and then the varnish may be rubbed over them by the proper brushes made for that purpose, beginnhig in the middle, and passing the brush to one end, and then with another stroke from the middle, passing it to the other. But no part should be crossed, or twice passed over, in forming one coat, where it can be possibly avoided. When one coat is dry, another must be laid over it ; and this must be continued at least five or six times or more, if, on trial, there be not sufficient thickness of varnish to bear the polish without laying bare the painting or ground- colour underneath. When a sufficient number of coats is thus laid on, the work is fit to be polished; which must be done, in common cases, by rubbing it with a rag dipped in Tripoli or rotten-stone finely powdered ; but towards the end of the rubbing, a little oil of any kind should be used along with the powder ; and when the work appears sufficiently THE SCHOOL OF USEFUL ARTS. 27 bright and glossy, it should be well rubbed with the oil alone^ to clean it from the powder, and give it a still brighter lustre. In case of white grounds, instead of Tripoli or rotten- stone, tine putty or whiting must be used ; both of which should be washed over to prevent the danger of damaging the work, from any sand or gritty matter that may happen to be mixed with them. It is a great improvement in all kinds of japan work, to harden the varnish by means of heat ; which in every degree that it can be applied, short of what would burn or calcine the matter, tends to give it a more firm and strong texture. Where metal forms the body, a very hot stove may be used ; and the pieces of work may be continued in it a considerable time, especially if the heat be gradually in- creased j but where wood is in question, heat must be sparingly used, as it would otherwise warp or shrink the body, so as to injure the general figure. HOUSE-PAINTING. This branch of painting is very extensive, comprehend- ing the mechanical processes for preserving and orna- menting walls of houses, furniture, &c. Of the utensils, brushes and pencils of all sizes are requisite : the brushes ought to be straight, round, and smooth ; they should before using be washed some time in warm water, that the wood of the handle may swell and retain the hairs, which would otherwise be apt to fall off, and adhere to the work. The brushes are commonly made of boar’s bristles, or of a mixture of bristles and hair 5 the pencils are made of badger’s or other fine hair, and fixed in quills of different sizes. The vessels used to hold the various paints should all be well varnished, to prevent their drying quickly. When the colours are ground in water, they should be diluted in size made from parchment. Colours ground in oil are also diluted with pure oil, or oil mixed with tur- pentine, which makes them easy to work ; but when the varnish is added, only what is requisite for the moment c 2 28 THE SCHOOL OF USEFUL ARTS. should be prepared, as it must be immediately applied. The addition of varnish gives the colours great brilliancy, and dries speedily, but more art is necessary in using them. This part of painting is divided into water and oil colours, with or without the admixture of any varnish. WATER COLOURS. Painting in water colours is to be done with those which are ground down in water, and then diluted in size j it is also divided into common and varnished paint- ing. Before any of these are applied, it is necessary to take care that no grease remain on the substance to be painted. The several layers or coats, especially the first, should be laid on warm, but not so as to affect the wood ; and the last coat, given immediately before the varnish, is the only one which should be applied cold. Whatever colour is to be laid, a white ground is the most proper, as it unites well with all other colours, which always par- take a little of the nature of the ground. Works re- quiring no particular care or preparation, such as stair- cases, cielings, and the like, are commonly done with water colours, applied with size ; for a common w'hite Spanish whitening is employed, pounded and steeped in water until it be dissolved 5 then infuse a due quantity of charcoal black for the same time, and mix it with the white until you have got the tint desired. These are next mixed together with good size, sufficiently thjck and warm, and laid on in as many coats as may be requisite. If the walls to be painted are new built, a greater quantity of size is necessary than when they are old. In general it is to be observed, that all colours should be ground, and mixed to the proper degree of tint in water only, and the size added afterwards, to give them consistency. A very beautiful white colour is given to walls by the following preparation. Take a quantity of the very best lime, and pass it through some fine linen into a large tub, furnished with a spigot at the height of the surface of the lime : fill the tub with clean soft water, then beat up the mixture with a piece of wood, and let it settle for twenty-four hours. The spigot is then opened, and the water diawn off ; in the same way fresh water is added. THE SCHOOL OF USEFuL ARTS. 29 and drawn oil* repeatedly, until the lime has acquired a very brilliant whiteness. When the last water is carried off, the lime will be found in the consistency of paste ; but, before it be used, a small quantity of Prussian blue, or indigo, must be added, to relieve the brightness of the white, and a little turpentine to improve its brilliancy. The proper size for using with this composition is made of glove-leather and alum, to be applied with a strong brush in five or six layers on new plaster. The wall is next to be rubbed strongly, after the painting is dry, with a stiff brush, which will give it a lustre resembling stucco or marble. Cielings and roofs of rooms, when new, may be done with good whitening, mixed with a little charcoal black, to prevent the white from turning reddish. Infuse them separately in water, and mix the whole with half water and half glove-^leather size. If the roof has been whitened before, the old colour must be entirely scraped off, and two or three layers of lime applied for a ground, and the new colour laid on in two or three coats. But however expeditious and beautiful the method of using water colours may be, yet, by the introduction of varnish, several advantages are produced, such as that the colours are not liable to fade, they reflect the light, give no offen- sive smell, but permit the chamber or house to be in- habited soon after the operation, and the wood is preserved from insects and moisture. To make a fine varnish water colour, sundry operations are necessary ; namely, to size the wood, to prepai*e the white, to soften and rub the work, to clean the mouldings and carved parts, to paint, to size, and varnish the whole. The wood is sized in this manner : take three heads of garlic, and a handful of leaves of wormwood, boil them in three pints of water down to one, pass the juice through a linen cloth, and mix it with a pint of parch- ment size, add half a handful of salt, and half a pint of vinegar, and boil the whole over a fire. With this boiling liquor size the wood, allowing it to penetrate into the carved and smooth places, but taking care to take it as clean off the work as possible, or at least to leave it at no place thicker than at another. The first operation fills up the pores of the wood, and prevents the materials afterwards from collecting in a body, which would cause c a 30 THE SCHOOL OF USEFUL ARTS. the other layers to fall off in scales. The next things to be (lone is, in a pint of strong parchment glue or size, diluted with four pints of warm water, put two handsful of fine whitening, and infuse the whole for half an hour ; stir this well, and give a single coat of it very warm, but not boiling, laid on smooth and equal, dashing repeated strokes into the hollows and carved parts. To prepare the white colour, take some strong parchment size, and sprinkle lightly over it with the hand, the fine whitening to the thickness of half an inch : allow this to soak in, for half an hour, near the fire, to keep the size warm, and then stir it with the brush till the lumps are broken down, and the composition be properly mixed. With this white lay on as many coats as the nature of the work requires, observing that the layers should be all as nearly as possible of the same colour and consistency. The last coat, however, ought to be cleaner and thinner than the others, and this is produced by adding a little water; it is applied more lightly, taking care with small brushes to cover all the difficult places of the carvings and mould- ings. It is also necessary, between the drying of the different layers, to fill up all the defects with white mastich and size. What is called softening the work, is to give it, when whitened, a smooth and equal surface, and to rub it over with pumice. When the wood is dry, take small pieces of wood and of pumice shaped in different ways, for working on the pannels and mouldings ; then take cold water, (for any heat would destroy this sort of work) moisten the wall with a brush, or at least so much of it as can be worked at once, lest the water should penetrate too much, and spoil what has been formerly done : then rub and smooth it with the pieces of wood and pumice ; next wash it with a brush as the polishing goes on, and rub it over with a piece of new linen, which will give a fine lustre to the whole. OIL COLOURS. By means of oil, all colours are longer preserved, and not drying so speedily as water colours, they give the artist more time to smooth, finish, and retouch his work : the colours also being more marked, and mixing better THE SCHOOL OF USEFUL ARTS. 31 together, give more distinguishable tints, and more vivid and agreeable gradations j the colouring is thus rendered more sweet and delicate. Paintings are executed either with simple oil : or with oil and varnish. When bright colours, such as white and light grey, are ground and diluted in oil, that of walnuts is the’ best, but for dark colours, linseed oil is to be preferred. They must be laid on cold, unless it be on new or moist plaster, which re- quires them to be boiling. Stir the colour often, to pre- vent it from subsiding, and leaving the oil on the surface ; but if, notwithstanding care, the colour should be thick at the bottom, a little more oil must be added from time to time. In general, all works to be painted in oil ought to receive a coat or two of white lead ground, and diluted in oil. Where the painting is to be exposed to the air, as in doors, windows, and other similar works where var- nishing is not applied, the layers of paint should be made with pure walnut oil, in work within doors, or when the painting is to be varnished, the first layer ought to be ground and diluted in oil. When there are many knots in the wood, as is the case with fir, which do not easily take the colour, it is necessary when painting with pure oil, to apply a little oil mixed with litharge on the knots. As there are several colours which are difficult to dry when ground in oil, it becomes necessary to introduce other substances of a drying quality, by which the effect is produced. Of these there are vasious sorts ; one com- position frequently used is prepared in this manner : — Take half an ounce of litharge, as much calcined white lead, as much powdered umbre, and the same quantity of talc. These ingredients are boiled for two hours on a slow equal fire, with one pound of linseed oil, and kept stirring the whole time : this must be carefully skimmed and clarified, and the older it grows, it is the better for use. Doors and windows to be painted in pure oil colours, have first a coating of white lead ground in wal- nut oil, with a little of the above drying composition, or siccative ; then another coat of the same, to which, if a greyish colour be wanted, add a little Prussian blue and charcoal black, also ground in walnut oil. The last coats should have less oil in them than the first, and the colour will be more beautiful, and less apt to blister in the sun. 52 THE SCHOOL OF USEFUL ARTS. Walts that are to be painted in this way ought to be very dry, and receive two or three layers of hot linseed oil, to harden the plaster, then two layers of ochre or white lead, ground in the same oil ^ and when these are dry, the wall is ready to be painted. Arbours and all sorts of garden work require a coat of white lead ground ill walnut oil, and diluted in the same, with the addition of a little litharge^ then two layers of green, consisting of one pound of verdigris to two pounds of white lead, ground up in walnut oil. This green is also of great use in the country for doors, window shutters, seats, rails, whether of iron or wood, and in general for all works exposed to the weather. Statues, vases, and all other stone ornaments, either within doors or without, ought first to be well cleaned, then have a couple of coats of white lead ground in oil of pinks, and be finished by an additional coat of the same. In painting on walls not exposed to the air, or on new plaster, the best way is to give one or two coats of boiling linseed oil, applying it till the walls are quite soaked ; then give a coat of white ceruse, ground in walnut oil ; and lastly, two other layers of ceruse in oil of walnuts. In this way walls are painted white; but any other colours may be applied by employing them in a similar manner. To paint chairs, benches, stone or plaster, give a layer of white ceruse ground in walnut oil, and diluted in the same, having in it a little litharge to make it dry: then apply a layer of the tint you have chosen, and afterwards one or two more, varnishing the whole with spirit of wine varnish. A steel colour is produced by ceruse, Prussian blue, fine lac and verdigris, mixed in such proportions as to give the colour required. Balustrades and railings are done with lamp black and varnish of vermilion in two coats, and finished with spirits of wine varnish. Since the discovery of oil painting, and the knowledge that wood is preserved by it, and especially since the discovery of a varnish without smell, and which even takes away the smell of oil, the painting of apartments in oil has been justly preferred to any other method. Oil slops the pores of the wood, and although it does not altogether resist the impression of moisture, yet the effect is so little perceptible, that it is to be recommended as the THE SCHOOL OF USEFUL ARTS. 33 best w^ay known to preserve wood. To preserve wains- coting in the must effectual manner, it is proper to paint the wall behind it with two or three coats of common red, ground and diluted in linseed oil. The wainscot itself is painted first with a coat of white lead ground, and diluted in walnut oil; when this is dry, two other coats of the same are to be applied. Two or three days afterwards, when the colour is dry, apply a coat or two of the white varnish without smell to drown that of the colour. The first coats of this work may also he done in water colours, and the varnish applied as before. When the pores of the wood are well slopped by the white preparation, a layer of white lead, ground and diluted in walnut oil, may be applied, which will be sufficient, the w^ood being pre- viously primed, and then the intended colour and varnish. PAINTING IN VARNISH. This is to employ colours ground and diluted in var- nish, either in spirits of wine or oil, on all sorts of mate- rials! In this manner, wainscoting, furniture, carriages, &c. are painted. To paint apartments in .this way, give two layers of fine whitening diluted in a strong size, and boiling hot : then fill up any boles or unevenness of the wood with masticb in water, and when dry smooth the layers with pumice stone. When the wood is thus made even, suppose you were to paint a grey colour, take one pound of white ceruse, one drachm of Prussian blue, or of charcoal or ivory black ; put the whole into a piece of leather, so tied that the colours cannot escape, and shake them till they are sufficiently mixed ; then put two ounces of colour into a quartern of varnish, and when well mixed, apply two coats over the white ground. This being dry, put one ounce of colour into the same quantity of var- nish, and give another coat. Again, with half an ounce of colour in the same quantity of varnish, apply a third coat. As each of these dries, it must be carefully rubbed with a piece of coarse new cloth, but so as not to injure the surface of the colour. These three layers may be applied in one day, and if a still greater lustre is wanted, a fourth may be added in the same way. In this manner any other colour may be applied 5 and it is the only one 31 THE SCHOOL OF USEFUL ARTS* by which orpiment can be employed so as to preserve all its beauty, although retaining some of its defects. Another way of executing this kind of work, is to apply the colours and the varnish without previously using the size and the white ground. This method is very expeditious, but it has the defect of not being susceptible of the high polish and brilliancy of the former method. VARNISHES. The liquids in which the substances proper for making varnishes are generally dissolved in linseed oil, nut oil, sunflower oil, oil of turpentine, and spirits of wine. The resins usually employed, are copal, amber, mastic, sandarac, stick-lac and seed-lac, Chios turpentine, white rosin, dragon’s blood, gum elemi, asphaltum or Jew’s pitch, and common pitch. To these may be added, elastic gum ; cautchouc, or Indian rubber, though this is only used at present for balloons; Oil of turpentine only deadens the colour of paints : the var- nishes of amber and copal brighten them. TO MAKE DRYING OIL. The common method of making drying oil, is to put about half an ounce of litharge to each quart of the oil ; then boil it, not too hastily or violently, but with a moderate and equal fire, for about two hours, skimming it occasionally. If it be boiled too hard, it will become brown. When the sediment has subsided, separate the clean oil, which will grow clearer and better for keep- ing. When it is made perfectly drying, it will have a scum form at the top. It is supposed that white lead would answer the purpose, even better than litharge. GENERAL OBSERVATIONS ON VARNISHES OF ALL KINDS. 1st. As the substances that form varnishes are ex- tremely inflammable, they ought only to be made in a brick or stone room with a floor of the same materials. They should be cautiously kept from a fire that flames ; THE SCHOOL OF USEFUL ARTS. 35 nor should a lighted candle come near them, for the vapour, particularly of oil of turpentine and spirit of wine, will catch lire at some distance by means of flame of any kind. The operator should always have by him a woollen cloth or small blanket in a tub of water to cover the vessel containing the ingredients in case of their taking fire. They can only be put out by thus excluding the air. 2d. The substances should be freed, as much as pos- sible, from impurities of every kind, particularly sanda- rac, and preserved free from dust. The utmost clean- liness in and about the vessels is essentially necessary to good colour and transparency. 3d. The substances, after being broken into pieces, freed from impurities and heterogeneous substances, should be put by themselves into the melting-pot. If reduced to powder or very small pieces, they stick to the sides of the pot, and burn and hurt the colour. 4th. All the resins should be kept in vessels well stopt and closed from dust. So of the oils and spirit. 5th. When the varnish is made, it should be left some time for the dregs to settle : then be poured off clear, and then be filtered through silk or lawn. 6th. For goods that are not to be exposed to the heat of the sun, the spirit varnishes will answer : but as sandarac and mastic will melt in the sun, the oil var- nishes of copal and amber are the most proper. 7th. Glazed earthen vessels are better than iron: copper becomes rusted in oil, and therefore is not to be used. The most scrupulous cleanliness is necessary to success, OBSERVATIONS ON SPIRIT VARNISHES. 1st. A water-bath is the proper heat for spirit var- nishes; a sand-bath is too hot, and embers or coals dangerous. When the water once boils, keep it boiling till the substances are dissolved. This you will find by stirring it with a glass, or white wooden spatula, or a tobacco- pipe. By dissolving salt in the water, you may increase 36 THE SCHOOL OF USEFUL ARTS. the heat. When substances are not quite dissolved, never put them on the fire a second time to finish the solution. Never fill the vessels but about three parts full. 2d. Gum elemi gives consistence to the varnish, but should be used in small proportions. Brilliancy is given by Venice and Chio turpentine. 3d. Turpentine should always be melted separately, when the substances are dissolved ; it should be melted in a small quantity of spirit of wine, and then added. After the turpentine is added, give the water-bath six or eight boils, and then take it off, and strain it through a very fine sieve or fine linen. It will be still clearer by standing. 4th. The general proportion of sandarac is about ten or twelve ounces to a quart of spirit, and so of the other gums : if others are substituted, the sandarac must be proportionally diminished. The spirits of wine should fire gunpowder. 5th. If you want red or black varnishes, dragon’s blood and vermilion, Jew’s pitch and lamp black, will answer your purpose. 6th. Seed-lac makes harder varnish than shell-lac ; about ten ounces to the quart is enough. OBSERVATIONS ON OIL VARNISHES. 1st. Copal and amber are the two principal substances for oil varnishes ; as each of them possesses the property of making a hard and transparent varnish, they need not be mixed; but copal should be reserved for the lighter coloured varnishes. Amber, however, is tougher than copal, and a little of it certainly improves copal varnish, if the tinge of colour is no objection. 2d. It requires a stronger fire to dissolve copal and amber when mixed with oil than alone ; a strong heat hurts the colour. Melt therefore these resins by them- selves, broken into small pieces ; employ no more heat than is necessary to melt them ; when melted, add to them the hot linseed oil by degrees, stirring as you pour it in j then give a few boilings to incorporate the whole. THE SCHOOL OF USEFUL ARTS. 37 Sd. If you have more than one resin to add, melt the hardest first, otherwise the most fusible will burn before the other is melted. 4th. A sand-bath, or bright coals that do not flame, is the proper heat for oil varnishes : but give no more heat than is barely necessary to melt them. 6th. The vessels should be glazed earthenware with covers ; and new ones used, for copal varnish especially, every time. 6th. When the oil and the resin are incorporated and well stirred together, add the hot oil of turpentine; this should be about double the quantity of the oil employed ; but the oil should not be boiling hot when the turpentine is poured in, otherwise it may catch fire. Stir it well. 7th. Filter or strain the varnish ; then let it rest at least forty-eight hours. The sediment will do for a coarser or more coloured varnish of the same kind : the oil mixed with the sediment will tarnish the colour at the second melting. Co]pal Spirit Varnish , — Dissolve half an ounce of camphor in a pint of spirits of wine ; put it into a cir- culating glass, and add four ounces of copal, in small pieces ; set it in a sand-heat so, regulated that the bub- bles may be counted as they rise from the bottom ; and continue the same heat till the solution is completed. This is a very bright solution of copal : it is an excel- lent varnish for pictures, and may perhaps be found to be an improvement in fine japan works, as the stoves used in drying those articles may drive off* the camphor entirely, and leave the copal pure and colourless upon the work. Colourless Spirit Varnish , — To one quart of rectified spirit, add tw o ounces of mastic, in drops, and six ounces of sandarac ; when well dissolved, add four ounces of pure Venice turpentine. If it be wanted harder, substitute two ounces of gum- lac, half an ounce of gum elemi, and two ounces of clear white resin, instead of the mastic and turpentine, but the colour will not be so good. The first is proper for toilet boxes, &c. and the last for cane chairs, D 38 THE SCHOOL OF USEFUL ARTS. furniture, and wainscot, which are much handled. If required to be a reddish colour, add a little dragon’s blood. White Spirit Varnish . — Dissolve gum sandarac and gum mastic in spirits of wine ; leave it to settle for two days ; then strain it through a linen cloth, let it stand for some time, pour off the clear liquid, and bottle it for use. Another, by Dr. Withering , — Take of gum sandarac an ounce and a half ; mastic, in drops, half an ounce ; gum elemi, a quarter pf an ounce ; oil of spike lavender, a quarter of an ounce j put them into a half-pint phial, and fill it up with best spirits of wine. Let it stand in rather a warm place, till all the gums are dissolved, then pour olF the varnish into a clean phial, and it will be ready for use. To make Gold Varnish . — This ingenious process, which is at present employed throughout Europe, in gilding w^ooden frames, coaches, and various other articles, and w’^hich was formerly used in the preparation of the now old-fashioned leather tapestry, was invented towards the end of the sixteenth century. The com- position is as follows : — Take gura-lac, and having freed it from the filth and bits of wood with which it is mixed, put it into a small linen bag, and wash it in pure water, till the water be- comes no longer red, then take it from the bag and suffer it to dry. When it is perfectly dry, pound it very fine, because the finer it is pounded it will dissolve the more readily. Then take four parts of spirits of wine, and one of gum, reduced as before directed, to an im- palpable powder, so that for every four pounds of spirits you may have one of gum ; mix these together ; and, having put them into an alembic, graduate the fire so that the gum may dissolve in the spirits. When dis- solved, strain the whole through a strong piece of linen cloth ; throw away w hat remains in the cloth, as of no use, and preserve the liquor in a glass bottle closely corked. This is the gold varnish which may be employed for gilding any kind of wood. When you wish to use it, you must, in order that the THE SCHOOL OF USEFUL ARTS. 39 work may be done with more smoothness, employ a brush made of the tail of a certain quadruped called vari, well known to those who sell colours for painting ; and with this instrument dipped in the liquor, wash over gently, three times, the wood which has been sil- vered. You must, however, remember, every time you pass the brush over the wood, to let it dry ; for in so doing, your work will be extremely beautiful, and have a resemblance to the finest gold. Seed-lac Varnish. — Put a quart of spirits of wine into a wide-mouthed bottle, and add thereto eight ounces of seed-lac, that which is large grained, bright, clear, and freed from dirt and sticks. Let it stand two days, or longer, in a warm place, often shaking it ; then strain it through a flannel into another bottle, when it will be fit for use. To make Chinese Varnish, — Take of gum-lac in grains four ounces ; put it into a strong bottle, with a pound of good spirits of wine, and add about the bulk of a hazel-nut of camphor ; allow them to mix in sum- mer in the sun, or in winter on hot embers, for twenty- four hours, shaking the bottle from time to time ; pass the whole through a fine cloth, and throw away what remains upon it. Then let it settle for twenty-four hours, and you will find a clear part in the upper part of the bottle, which you must separate gently, and put into another phial, and the remains will serve for the first layers. Coloured Varnish for Drawings, Prints, — Boil four ounces of isinglass, in small pieces, in one quart of brandy or spirits of wine, expose it to the air, and when only warm, wash over the print or drawing (which should be previously mounted), and let it stand till quite dry ; then wash it again at a small distance from the fire, or it will blister, which repeat two or three times; then go twice over with the following white varnish : take of gum sandarac and gum mastic equal parts ; dissolve them in spirits of wine ; let them settle two days, then strain through a linen cloth, and pour the clear liquor into a bottle for use. D 2 40 THE SCHOOL OF USEFUL ARTS. Varnish for Violins and other Musical Instruments , — Put four ounces of gum sandarac, two ounces of lac, two ounces of gum mastich, one ounce of gum elemi, into a quart of alkohol, and hang them over a slow lire till they are dissolved ; then add two ounces of turpentine. Varnish for employing Vermilion for painting Car- riages. — Dissolve in a quart of alcohol, six ounces of gum-lac, and four ounces of resin ; afterwards add six ounces of the cheapest kind of turpentine : mix it with a proper quantity of vermilion when it is to be used. Copal Oil Varnish. — Melt slowly one pound of copal, and add half a pint of boiling drying oil. When in- corporated, add one pint of oil of turpentine, made hot. From half a pint, to three pints of boiling drying oil is to be now added, according to the consistence re- quired. Martinis Copal Var7iish. — In a large gallon earthen pot, with a cover like a chocolate pot, melt four ounces of Chio turpentine : when fluid, pour in eight ounces of amber powdered ; set it on the fire a quarter of an hour. Take off the pot ; add to it one pound of pounded copal, four or more of turpentine, and one gill of warm oil of turpentine. Increase the heat a little ; when it has been on the fire half an hour, take it off*, stir the ingredients, adding two ounces of the finest and whitest colophony, or resin. Set it again on the fire, and in- crease the heat till the whole is quite fluid. Remove the pot; let the heat subside a little; have ready twenty-four ounces (about one pint and a quarter) of drying linseed oil, poppy, or nut oil, and pour it boiling hot by degrees into your gums, and stir them well. When mixed, set it again on the fire, stirring it till it boils up ; then take it off*, and add a quart of turpentine made hot ; stir and give it one boil more ; then add another pint of turpentine made hot ; stir it well, give it one more boil, and it is enough. Strain it ; if thicker than linseed oil, thin it with oil of turpentine. Let it stand a month before it is used. It should be made in an open yard, for the frequent practice is very unwhole- some. Great danger will attend the addition of copal, as the THE SCHOOL OF USEFUL ARTS. 41 same heat which would be required to dissolve the copal would volatilize the turpentine, and take fire if the vapour were directed to the flame. Common Varnish. — Melt together one pound of resin, one ounce of gum elemi, eight ounces of drying oiJ^ and sixteen ounces of oil of turpentine. Common Turpentine Varnish. — This is frequently made by dissolving one pound of turpentine, or about ten ounces of resin, in oil of turpentine alone. Elastic Gum Va7'nish. — Digest the Indian rubber, cut in small pieces, with thirty-two parts of oil of turpen- tine, for twenty-four hours, in a warm place. Rosemary, lavender, and other essential oils also dissolve it. So does nitric ether, if softened by boiling water, or in a solution of alum ; Indian rubber may be joined after cutting. Vaimish for rendering Silk air and water tight, — Put a pound of bird-lime, and half a pint of the drying oil, into a pot of iron or copper, holding about a gallon, and let it boil gently over a slow charcoal fire, till the bird-lime ceases to crackle ; then pour upon it two pints and a half of drying oil, and boil it for about an hour longer, stirring it often with an iron or wooden spatula. As the varnish in boiling swells much, the pot should be moved from the fire, and replaced when the varnish subsides. While it is boiling, it should be occasionally examined, in order to determine whether it has boiled enough. For this purpose, take some of it upon the blade of a large knife, and after rubbing the blade of another knife upon it, separate the knives; when, on their separation, the varnish begins to form threads between the two knives, it has boiled enough, and should be removed from the fire. When it is almost cold, add about an equal quantity of spirits of turpen- tine ; mix both well together, and let the mass rest till the next day ; then having warmed it a little, strain and bottle it. If it is too thick, add spirits of turpentine. This varnish should be laid upon the stuff when per- fectly dry, in a luke-warm state ; a thin coat of it upon one side, and, about twelve hours after, two other coats D 3 42 THE SCHOOL OF USEFUL ARTS. should be laid on, one on each side ; and in twenty-four hours the silk may be used. Mr, Blanchard^ s Varnish for Air Balloons. — Dissolve elastic gum (Indian rubber,) cut small, in five times its weight of spirits of turpentine, by keeping them some days together ; then boil one ounce of this solution in eight ounces of drying linseed oil for a few minutes, and strain it. Use it warm. Amber Varnish. — Melt eight ounces of Chio turpen- tine, pour in one pound of powdered amber by degrees, stirring it all the while; set it on the fire for half an hour, then add two ounces of white resin; stop the cover close, and increase the fire till the whole is melted. To this add one pound of hot drying oil; and then by degrees a quart of oil of turpentine. Amber can only be dissolved clear, by melting it with some less glutinous gum. Same process for copal varnish. To varnish Plaster Casts or Models. — Take about a quarter of an ounce of the finest white soap ; grate it small, and put it into a new glazed earthen vessel, with an English pint of water ; hold it over the fire till the soap is dissolved, then add the same quantity of bleached wax cut into small pieces : as soon as the whole is in- corporated, it is fit for use. Mode of Application. — Dry the model well at the fire, suspend it by a thread, and dip it in the varnish ; take it out, and a quarter of an hour after dip it in again; let it stand for six or seven days, then, with a bit of muslin rolled softly round your finger, rub the model gently, and this will produce a brilliant gloss ; but this part of the operation must be done with great care and a light hand, as the coat of varnish is thin. Another Way. — Take skim milk, from which the cream has been carefully taken olf, and with a cameFs- hair pencil lay over the cast till it holds out, or will imbibe no more ; shake or blow off any that remains on the surface, and lay it in a place free from dust; and when it is dry, it will look like polished marble. N.B. This last mode answers equally well with the former, but will not resist the weather. tHE SCHOOL OF USEFUL ARTS. 43 Varnish for Earthen-ware. — To make it white, glass «,nd soda in equal proportion must be pounded together, very fine, carefully sifted, and well mixed. The mix- ture must next be exposed to a strong heat till it is Tendered very dry. It is after that to be put into vessels which have been already baked; it will then be melted, and the varnish is made. It may be applied in the usual manner. French soft Varnish for Engravings. — One ounce of wax, one ounce of asphaltum or Greek pitch, half an ounce of common pitch, and a quarter of an ounce of Burgundy pitch. N.B. The celebrated Vivares, the landscape engraver, always used this varnish, in preference to any other. Varnish for Furniture. — To one^ part of white wax, add eight parts of oil of petroleum ; lay a slight coat of this mixture on the wood with a badger’s brush, while a little warm ; the oil will then evaporate, and leave a thin coat of wax, which should afterwards be polished with a coarse woollen cloth. To make Varnish for Oil Paintings. — According to the number of your pictures, take the whites of the same number of eggs, and to each picture take the bigness of a hazel-nut of white sugar-candy, dissolved, and mix it with a tea-spoonful of brandy ; beat the whites of your eggs to a froth ; then let it settle ; take the clear, put to it the brandy and sugar, and varnish over the pictures with it; this is much better than any other varnish, as it is easily washed off* when the pictures want cleaning again. Black Varnishes for Coaches and Iron-work. — This varnish is composed of asphaltum, resin, and amber, melted separately, and afterwards mixed ; the oil is then added, and afterwards the turpentine, as directed above. The usual proportions are, twelve ounces of amber, two of resin, two of asphaltum, six of oil, and twelve of turpentine. 44 THE SCHOOL OF USEFUL ARTS, Black Japan. — Melt eight ounces of amber ; and then melt, separately, four ounces of asphaltum, and four ounces of resin. Now add to both, eight ounces of boiling oil, and then sixteen ounces of oil of turpentine ; then stir in about an ounce of lamp black, and give the whole another boil or two. To prevent the Rays of the Sun from passing^ through Windows, — Pulverize gum tragacanth, and put it to dissolve for twenty-four hours, in whites of eggs, well beaten. Lay a coat of this on the panes of glass with a soft brush, and let it dry. Varnish for Pales and coarse Wood-work. — -Take any quantity of tar, and grind it with as much Spanish brown as it will bear, without rendering it too thick to be used as a paint or varnish, and then spread i.t on the pales, or other wood, as soon as convenient, for it quickly hardens by keeping. This mixture must be laid on the wood to be var- nished, by a large brush, or house-painter^s tool ; and the work should then be kept as free from dust as poS" sible, till the varnish be thoroughly dry. It will, if laid on smooth wood, have a very good gloss, and is an excellent preservative of it against moisture ; on which account, as well as its being cheaper, it is far preferable to painting, not only for pales, but for weather-boarding, and all other kinds of wood- work for grosser purposes. Where the glossy brown colour is not liked, the work may be made of a greyish brown, by mixing a small proportion of white lead, or whiting, or ivory black, with the Spanish brown. CEMENTS. Cements require to be of various compositions, ac- cording to the substances to which they are applied, and whether they are to be exposed to heat or moisture. Common glue is formed by extracting, by means of THE SCHOOL OF USEFUL ARTS. 45 hot Water, the gelatinous part of cuttings or scraps of coarse leather, or the hides of beasts. It is never manufactured but in the large way, and therefore not necessary to be described here. Isinglass Glue,' — Isinglass glue is made by dissolving beaten isinglas in water, by boiling, and, having strained it through a coarse linen cloth, evaporating it again to such a consistence, that being cold, the glue will be perfectly hard and dry. This cement is improved by dissolving the isinglass in any proof spirit by heat, or by adding to it, when dissolved in water, an equal quantity of spirits of wine. It is still further improved by adding to the isinglass, previous to its solution in spirits, one third of its weight of gum ammoniac. Expose the mixture to a boiling heat until the isinglass and gum are dissolved, and until a drop of the composition becomes stiff instantly as it cools. This isinglass glue is far preferable to common glue for nice purposes, being much stronger, and less liable to be softened either by heat or moisture. Parchment Glue. — Take one pound of shreds of parch- ment, or vellum, and boil it in six quarts of water till the quantity be reduced to one quart; strain off the fluid from the dregs, and then boil it again till it be of the consistence of glue. The same may be done with glovers’ cuttings of leather, which are dressed with alum instead of being tanned ; this will make a colourless glue. Glue for Sign-boards to stand the Weather, — Melt common glue with water to a proper consistence ; then add one eighth of boiled linseed oil, dropping it into the glue gently, and stirring it all the time. A very strong glue is made by adding some powdered chalk to common glue. Another that will resist water, is made by adding half a pound of common glue to two quarts of skimmed milk. Lip Glue, for Paper, Silk, and thin Leather, — Take of isinglass glue and parchment glue each one ounce ; of 48 THE SCHOOL OF USEFUL ARTS. sugar-candy and gum tragacanth each two drachms ; add to them an ounce of water, and boil the whole together till the mixture appears, when cold, of the pro- per consistence of glue. Then form it into small rolls, or any other figure that may be most convenient. This glue may be wet with the tongue, and rubbed on the edges of the paper, silk, &c. that are to be cemented, which will, on their being laid together, and suffered to dry, unite as firmly as any other part of the substance. Lapland Glue . — The bows of the Laplanders are com- posed of two pieces of wood glued together : one of them of birch, which is flexible, and the other of fir, which is stiff, in order that the bow, when bent, may not break, and that when unbent it may not bend. When these two pieces of wood are bent, all the points of contact endeavour to disunite themselves ; and to pre- vent this, the Laplanders employ the following cement : they take the skins of the largest perches (it is probable that eel skins would answer the same purpose), and having dried them, moisten them in cold water until they are so soft that they may be freed from the scales, which they throw away. They then put four or five of these skins in a rein deer’s bladder, or they wrap them up in the soft bark of the birch-tree, in such a manner that water cannot touch them, and place them thus covered into a pot of boiling water, with a stone above them to keep them at the bottom. When they have boiled about an hour, they take them from the bladder or bark, and they are then found to be soft and viscous. In this state they employ them for glueing together the two pieces of their bows, which they strongly compress and tie up till the glue is well dried. These pieces never afterwards separate. Glue from Cheese . — Take skimmed milk cheese, free from the rind, cut it into slices, and boil it in water, stirring it with a spoon until it be reduced to a strong glue, which does not incorporate with water. Then throw away the hot water ; pour cold water over the glue, and knead it afterward in warm water, subjecting it to the same process several times. Put the warm glue on a grinding stone, and knead it with quick lime until THE SCHOOL OF USEFUL ARTS. 47 you have a good glue. When you wish to use this glue you must warm it ; if it be employed cold it is not so strong, but it may also be used in that manner. This glue is insoluble in water, as soon as it is dry, and it becomes so in forty-eight hours after it has beeen applied. It may be used for glueing wood, and for cementing marble, and broken stone and earthen-ware. Baits for catching fish may also be made of it. Fish are very fond of it, and it resists water. Jewellers^ Cement . — In setting precious stones, pieces are sometimes broken off by accident. In such cases, they often join the pieces so correctly, that an inex- perienced eye cannot discover the stone to have been broken. They employ for this purpose a small piece of gum mastic applied between the fragments, which are previously heated sufficiently to enable them to melt the interposed gum. They are then pressed together to force out the redundant quantity of gum. Turkey Cement for joining Metals, Glass, ^c. — Dis- solve five or six bits of mastic, as large as peas, in as much spirits of wine as will suffice to render it liquid : in another vessel dissolve as much isinglass (which has been previously soaked in water till it is swollen and soft) in brandy or rum, as will make two ounces by measure of strong glue ; and add two small bits of gum galbanum or ammoniacum, which must be rubbed or ground till they are dissolved ; then mix the whole by a sufficient heat ; keep it in a phial stopt, and when it is to be used, set it in hot water. Cement for broken China, Glass, — Take quick- lime and white of eggs, or old thick varnish; grind and temper them well together, and it is ready for use. Drying oil and white lead are also frequently used for cementing china and earthen- ware ; but this cement requires a long time to dry. Where it is not necessary the vessels should endure heat or moisture, isinglass glue, with a little tripoli, or chalk, is better. The juice of garlic also forms a strong cement, and the joining can scarcely be perceived. Cement for Chemical Glasses to hear the Fire . — Mix equal quantities of wheat flour, fine powdered Venice 48 THE SCHOOL OF USEFUL ARTS. glass, pulverized chalk, with half the quantity of fin«? brick-dust, and a little scraped lint in the whites of eggs : this mixture is to be spread upon a linen cloth, and applied to the crack of the glasses, and should be well dried before they are put into the fire. A Cement useful for Turners. — Take resin one pound, pitch four ounces; melt these together, and, while boil- ing hot, add brick-dust, until, by dropping a little upon a stone, you perceive it hard enough ; then pour it into w ater, and immediately make it up in rolls, and it is fit for use. Another, finer » — Take resin one ounce, pitch two ounces ; add red ochre, finely powdered, until you per- ceive it strong enough. Sometimes a small quantity of tallow is used, according to the heat of the weather, more being necessary in winter than in summer. Either of these cements is of excellent use for turners. By applying it to the side of a chuck, and making it warm before the fire, you may fasten any thin piece of wood, which will hold while turned ; when you want it off again, strike it on the top with the tool, and it will drop oiF immediately. Strong Cement for Electrical Purposes, — Melt one pound of resin in a pot or pan over a slow fire ; add thereto as much plaster of Paris, in fine powder, as will make it hard enough ; then add a spoonful of lin- seed oil, stirring it all the while, and try if it be hard and tough enough. If it is not sufficiently hard, add more plaster of Paris ; and if not tough enough, a little more linseed oil. This is as good a cement as possible for fixing the necks of globes or cylinders, or any thing else that requires to be strongly fixed, for it is not easily melted when cold. Another, softer, — Take resin one pound, bees-waxone ounce ; add thereto as much red ochre as will make it of sufficient stiffness ; pour it into water, and make it into rolls, and it is fit for use. This cement is useful for cementing hoops on glasses, or any other mounting of electrical apparatus. Cement for Glass Grinders, — Boil pitch, and add thereto, stirring it all the while, fine sifted wood ashes, THE SCHOOL OF USEFUL ARTS. 49 until it is of a proper temper ; the addition of a little tallow may be added, if necessary. Another for small Work , — To four ounces of resin add one-fourth of an ounce of bees wax, melted to- gether, add four ounces of whiting, made previously red hot. The whiting should be put in while hot, that it may not have time to imbibe moisture from the atmosphere. Shell-lac is a very strong cement for holding metals, glass, or precious stones, while cutting, turning, or grinding them. The metal, &c. should be warmed to melt it. For fastening ruby cylinders in watches, and similar delicate purposes, shell-lac is excellent. To solder or cement broken Glass . — Broken glass may be soldered or cemented in such a manner as to be as strong as ever, by interposing between the parts glass ground up like a pigment, but of easier fusion than the pieces to be joined, and then exposing them to such a heat as will fuse the cementing ingredient, and make the pieces agglutinate without being themselves fused. A glass for the purpose of cementing broken pieces of flint glass, may be made by fusing some of the same kind of glass previously reduced to powder, along with a little red lead and borax, or with the borax only. Cement for Derbyshire Spar and other Stones . — A cement for this purpose may be made with about seven or eight parts of resin and one of bees-wax, n^elted together with a small quantity of plaster of Paris, If it is wished to make the cement fill up the place of any small chips that may have been lost, the quantity of plaster must be increased a little. When the ingredients are well mixed, and the whole is nearly cold, the mass should be well kneaded together. The pieces of spar that are to be joined, must be heated until they will melt the cement^ and then pressed together, some of the cement being previously interposed. For marbles, &c. this cement is to be appropriately coloured. Melted sulphur applied to fragments of stones pre- vious heated (by placing them before a fire) to at least the melting point of sulphur, and then joined with the E 50 THE SCHOOL OF USEFUL ARTS. sulphur between, makes a pretty firm and durable joining. Little deficiencies in the stone, as chips out of corners, &c. may also be filled up with melted sulphur, in w^hich some of the powder of the stone has been melted. The stone should be heated. Cement that will stand against boiling Water , — In joining the flanches of iron cylinders, and other parts of hydraulic and steam engines, great inconvenience is often experienced from the want of a durable cement. Boiled linseed oil, litharge, red and white lead, mixed together to a proper consistence, and applied on each side of a piece of flannel previously shaped to fit the joint, and then interposed between the pieces before they are brought home (as the workmen term it) to their place by the screw^s or other fastenings employed, make a close and durable joint. The quantities of the ingredients may be varied with- out inconvenience, only taking care not to make the mass too thin with oil. It is difficult in many cases instantly to make a good fitting of large pieces of iron work, which renders it necessary sometimes to join and separate the pieces repeatedly, before a proper adjust- ment is obtained. When this is expected, the white lead ought to predominate in the mixture, as it dries much slower than the red. A workman knowing this fact, can be at little loss in exercising his own discretion in regulating the quantities. It is safest to err on the side of the wffiite lead, as the durability of the cement is no way injured thereby, only a longer time is required for it to dry and harden. When the fittings will not admit easily of so thick a substance as flannel being interposed, linen may be substituted, or even paper. This cement answers well also for joining broken stones, however large. Cisterns built of square stones, put together with this cement, will never leak or want any repairs. In this case the stones need not be entirely bedded in it: an inch, or even less, of the edges that are to lie next the water need only be so treated ; the rest of the joint may be filled with good lime. THE SCHOOL OF USEFUL ARTS. 51 Cement or Mortar made on the Cotswold Hills, — On the Cotswold Hills in Gloucestershire, w'here lime is dear and sand not to be had, an excellent mortar is pre- pared at a moderate price. Invention is seldom mpre successful than when it is prompted by necessity. The scrapings of the public roads over these hills, being levigated limestone, more or less impregnated with the dung and urine of the animals travelling on them, are found to be a most admirable basis for cement. The scrapings alone are frequently used for ordinary walls ; and the general proportion, for even the best buildings, is not more than one part lime to three of scrapings. This mortar, of less than ten years standing, has been observed to possess a stone-like tenacity, much firmer than the common stone of the country, and consequently much harder than the stones from which either the basis or the lime w'as made. The method of preparing this cement is simply by collecting the road scrapings, slak- ing the lime, and mixing them very thoroughly together ; carefully picking out, as the mass is worked over, the stones or other foulnesses which may have been col- lected. For stone work, this is sufficient ; for brick work, it might be necessary to pass the materials through a sieve or screen, previously to their union in the state of mortar. Similar scrapings may be collected whenever limestone is used for repairing the roads. This admirable mortar may, therefore, be prepared with very little trouble and expense in such places. Cement for Stills, Alembics, and Retorts, — To prevent the escape of the vapour of water, spirits, and liquors not corrosive, the simple application of slips of moistened bladder will answer very well for glass, and paper with good paste for metal. Bladder, to be very adhe- sive, should be soaked some time in water moderately warm till it feels clammy : it then sticks very well : if smeared with white of eggs instead of water, it adheres still closer. Fire Lute, — For a fire lute, take porcelain clay from Cornwall (not pipe clay), let it be pounded small, and mixed up to the consistence of thick paint, with a solu- tion of two ounces of borax in a pint of hot water. For E 2 52 THE SCHOOL OF USEFUL ARTS. want of this peculiar kind of clay, slaked quick lime mixed up in the same manner may be used. This may be kept ready mixed in a covered vessel. Cold Lute, — ^Take equal parts, by measure, of the above clay and wheat flour ; mix them to a proper con- sistence with cold water. This is more tenacious than the fire lute, but does not keep so well. Another, — A very excellent lute for many purposes may be made by beating up an egg, both the white and the yolk, with half its weight of quick lime in powder. This lute is to be put upon a piece of linen, and applied as usual. It dries slowly, but becomes very compact, and acquires great hardness. Cement for Iron Flues. — Common salt and sifted wood ashes, equal parts, made into a paste with water, make a good cement for iron flues, &c. better than most other compositions, and may be applied when the flue is hot or cold. Iron filings and vinegar will do as well, or rather iron filings moistened with diluted muriatic acid. These are commonly used for filling up the spaces between cylinders. Blood Cement for repairing Copper Boilers^ — This cement is often used by coppersmiths to lay over the rivets and edges of the sheets of copper, in large boilers, to serve as an additional security to the joinings, and to secure cocks, &c. from leaking; it is made by mixing pounded quick lime with ox's blood. It must be applied fresh made, as it soon gets so hard as to be unfit for use. If the properties of this cement were duly in- vestigated, it would be found useful for many purposes to which it has never been yet applied. It is extremely cheap, and very durable. Cement for cracked Cast Iron Furnaces, — Take a small clod of fine new lime, slaked, and finely sifted, mix it up with white of eggs, well beaten, till it is of the consistence of pap or soft mortar, then add to it some iron tile dust, and with this composition fill up the inside of the crack (which will be sufficient), raising a little seam or bead upon it, and it will soon become hard and fit for use. THE SCHOOL OF USEFUL ARTS, 53 Cement to resist the Action of hot Water, — Take half a pint of milk, and mix with it an equal quantity of vinegar so as to coagulate the milk. Separate the curds from the whey, and mix the latter with the whites of four or five eggs, after beating them well up. The mix- ture of these two substances being complete, add sifted quick lime, and make the whole into a thick paste of the consistence of putty. If this mastic is carefully applied to broken bodies, or to fissures of any kind, and dried properly, it resists hot water. Cement^ to resist Moisture, may be formed by melting by heat, without water, common glue, with half its weight of resin ; to which must be added some red ochre, to give it body ; it is particularly useful for cementing hones to their frames. Japanese Cement, or Rice Glue, — This elegant cement is made by mixing rice flour intimately with cold water, and then gently boiling it. It is beautifully white, and dries almost transparent. Papers pasted together by means of this cement will sooner separate in their own substance than at the joining, which makes it extremely useful in the preparation of curious paper articles, as tea-trays, ladies’ dressing-boxes, and other articles which require layers of papers to be cemented together. It is, in every respect, preferable to common paste made with wheat flour for almost every purpose to which that article is usually applied. It answers well, in particu- lar, for pasting into books the copies of writings taken ofif by copying machines on unsized silver paper. With this composition, made with a comparatively small quantity of water, that it may have the consistence similar to plastic clay, models, busts, statues, basso- relievos, and the like, may be formed. When dry, the articles are susceptible of a high polish 5 and are very durable. Cement for joining broken Glass, China, Earthen- ware, ^c, — Take two ounces of good glue, and steep it for a night in distilled vinegar ; boil them together the next day, and having beaten a clove of garlic, with half an ounce of ox-gall, into a soft pulp, strain the juice through a linen cloth, using pressure, and add the E 3 64 THE SCHOOL OF USEFUL ARTS. same to the glue and the vinegar. Then take gum sandarac powdered, and turpentine, of each one drachm, and of sea coal and mastic powdered, each half a drachm, and put them into a bottle, with an ounce of highly rectified spirits of wine. Stop the bottle, and let the mixture stand for three hours in a gentle heat, fre- quently shaking it. Mix this tincture also with the glue while hot, and stir them w^ell together with a stick or tobacco-pipe, till part of the moisture be evaporated ; then take the composition from the fire, and it will be fit for use. When this cement is to be applied, it must be dipped in vinegar, and then melted in a proper vessel with a gentle heat; and if stones are to be cemented, it is proper to mix with it a little powdered tripoli or chalk : or if glass is to be conjoined, powdered glass should be substituted. To stop Cracks in Glass Vessels, — The cracks of glass vessels may be mended, by daubing them with a suit- able piece of linen over with white of egg, strewing both over with finely powdered quicklime, and instantly applying the linen closely and evenly. Cement for preserving Wood and Brick — This com- position is formed of mineral or coal tar, pulverized coal, (charcoal is esteemed the best), and fine well slaked lime ; the coal and lime to be well mixed together, pro- portioned at about four-fifths coal, and one-fifth lime ; the tar to be heated, and while hot, thickened with the mixture of coal and lime, until it becomes so hard that it may be easily spread upon the surface of a board, and not run when hot. Turpentine or pitch will answer nearly as well as tar, and plaster of Paris will answer instead of lime ; to be used in the same manner, and in about the same proportions. The cement must be ap- plied warm, and is found to be used easiest with a trowel. Flour Paste. — Flour paste is formed principally of wheaten flour, boiled in water till it be of a glutinous or viscid consistence. It may be prepared of these ingredients simply for common purposes ; but when it is used by book-binders, or for paper hangings, it is usual to mix with the flour a THE SCHOOL OF USEFUL ARTS. 6^ fifth or sixth of its weight of powdered alum j and where it is wanted still more tenacious, gum arabic, or any kind of size, may be added. DYEING. Permanent alterations in the colour of cloth can only be produced two ways ; either by producing a chemical change in the cloth, or by covering its fibres with some substance which possesses the wished-for colour. Re- course can seldom or never be had to the first of these methods, because it is hardly possible to produce a chemical change in the fibres of cloth without spoiling its texture, and rendering it useless. The dyer, there- fore, when he wishes to give a new colour to cloth, has always recourse to the second method. The substances employed for this purpose are called colouring matters^ ox dye stuffs; they are for the most part extracted from animal and vegetable substances, and have usually the colour they give to the cloth. As the particles of colouring matter, with which cloth when dyed is covered, are transparent, it follows, that all the light reflected from dyed cloth must be reflected, not by the dye stuff itself, but by the fibres of the cloth below the dye stuff. The colour, therefore, does not depend upon the dye alone, but also on the previous colour of the cloth. If the cloth be black, it is clear that we can- not dye it any other colour whatever : because as no light in that case is reflected, none can be transmitted, whatever dye stuff we employ. If the cloth were red, or blue, or yellow, we could not dye it any colour except black, because as only blue or red, or yellow rays, were reflected, no other could be transmitted. Hence the importance of a fine white colour when cloth is to re- ceive bright dyes. It then reflects all the rays in abundance, and therefore any colour may be given, by covering.it with a dye stuff which transmits only some particular rays. The colouring matter, however perfect a colour it possesses, is of no value, unless it adheres so firmly to 56 THE SCHOOL OF USEFUL ARTS. the cloth, so that none of the substances usually applied to cloth, in order to clean it, &c. can displace it. Now this can only happen when there is a strong affinity between the colouring matter and the cloth, and when they are actually combined together in consequence of that affinity. The facility with which cloth imbibes a dye depends upon two things ; namely, the affinity between the cloth and the dye stuff, and the affinity between the dye stuff and its solvent. It is directly as the former, and in- versely as the latter. It is of importance to preserve a due proportion between these two affinities, as upon that proportion much of the accuracy of dyeing depends. Wool has the strongest affinity for almost all colouring matters, silk the next strongest, cotton a considerably weaker affinity, and linen the weakest affinity of all ; therefore, in order to dye cotton or linen, the dye stuff should in many cases be dissolved in a substance for which it has a weaker affinity than for the solvent employed in the dyeing of wool or silk. Thus we may use oxyde of iron dissolved in sulphuric acid, or oil of vitriol, in order to dye wool; but for cotton and linen, it is better to dissolve it in acetous acid or vinegar. Were it possible to procure a sufficient number of colouring matters, having a strong affinity for cloth, to answer all the purposes of dyeing, that art would be exceedingly simple and easy. But this is by no means the case ; if we except indigo, the dyer is scarcely possessed of a dye stuff which yields of itself a good colour, sufficiently permanent to deserve the name of a dye. This difficulty, which at first sight appears insur- mountable, has been obviated by a very ingenious con- trivance. Some substance is pitched upon, which has a strong affinity, both for the cloth and the colouring matter. This substance is previously combined with cloth, which is then dipped into the solution containing the dye stuff. The dye stuff combines with the inter- mediate substance, which being firmly combqied with the cloth, secures the permanence of the dye. Sub- stances employed for this purpose are denominated mordanta. THE SCHOOL OF USEFUL ARTS. 57 The most important part of dyeing is undoubtedly the proper choice, and the proper application of mordants^ as upon them the permanency of almost every dye depends. Every thing which has been said respecting the application of colouring matters, applies equally to the application of mordants. They must be previously dissolved in some liquid, w hich has a weaker affinity to them than the cloth has, to which they are to be applied ; and the cloth must be dipped, or even steeped in this solution, in order to saturate itself with the mordant. Mordants, — Almost the only substances used as mor- dants, are earths^ metallic oxides, tan, and oil. Of earthy mordants, the most important and most generally used, is alumine. It is used either in the state of common alum, in which it is combined with sulphuric acid, or in that of acetite of alumine. Alum, when used as a mordant, is dissolved in water, and very frequently a quantity of tartar is dissolved along with it. Into this solution the cloth is put, and kept in it till it has absorbed as much alumine as is necessary. It is then taken out, and for the most part washed and dried. It is now a good deal heavier than it w^as before, owing to the alumine which has combined with it. Acetite of alumine has been but lately introduced into dyeing. This mordant is employed for cotton and linen, which have a weaker affinity than wool for alumine. It answ^ers much better than alum ; the cloth is more easily saturated with alumine, and takes, in conse- quence, both a richer and a more permanent colour. Besides alumine, lime is sometimes used as a mordant. Cloth has a strong enough affinity for it; but, in gene- ral, it does not answer so well, as it does not give so good a colour. When used, it is either in the state of lime-water, or of sulphate of lime dissolved in water. Almost all the metallic oxides have an affinity for cloth, but only two of them are extensively used as mor- dants, namely, the oxides of tin, and of iron. The oxide of tin was first introduced into dyeing by Kuster, a German chemist, who brought the secret to London in 1543. This period forms an era in the history of dyeing. The oxide of tin has enabled the 58 THE SCHOOL OF USEFUL ARTS. moderns greatly to surpass the ancients in the fineness of their colours; by means of it alone, scarle^ the brightest of all colours, is produced. Nitro muriate of tin is the common mordant employed by dyers. They prepare it by dissolving tin in diluted nitric acid, to which a certain proportion of muriate of soda, (common salt,) or of ammonia, is added. When the nitro muriate of tin is to be used as a mor- dant, it is dissolved in a large quantity of water, and the cloth is dipped in the solution, and allowed to re- main till sufficiently saturated. It is then taken out washed, and dried. Tartar is usually dissolved in the water along with nitro-muriate. Oxide of iron has a very strong affinity for all kinds of cloth. The permanency of the iron spots on linen and cotton is a sufficient proof of this. As a mordant, it is used in two states ; in that of sulphate of iron, and acetite of iron. The first is commonly used for wool. The salt is dissolved in water, and the cloth dipped in it. It may be used also for cotton, but in most cases acetite of iron is preferred. This is prepared by dis- solving iron, or its oxyde, in vinegar, sour beer, &c. and the longer it is kept, the more it is preferred. Tan has a strong affinity for cloth, and for several colouring matters ; it is therefore frequently employed as a mordant. An infusion of nut galls or of shumack^ or any other substance containing tan, is made in water, and the cloth is dipped in this infusion, and allowed to remain till it has absorbed a sufficient quantity of tan. Silk is capable of absorbing a very great proportion of tan, and by that means acquires a great increase of weight. Manufacturers sometimes employ this method of increasing the weight of silk. Tan is often employed also, along with other mor- dants, in order to produce a compound mordant. Oil is also used for the same purpose, in the dyeing of cotton and linen. The mordants with which tan most fre- quently is combined, are alumine, and oxyde of iron. Besides these mordants, there are several other sub- stances frequently used as auxiliaries, either to facilitate the combination of the mordant with the cloth, or to alter the shade of colour; the chief of these are, tartar ^ THE SCHOOL OF USEFUL ARTS. 59 ncetite of lead, common salt, sal ammoniac, sulphate, or acetite of copper, Sfc, Mordants not only render the dye permanent, but have also considerable influence on the colour produced. The same colouring matter produces very different dyes, according as the mordant is changed. Suppose, for instance, that the colouring matter be cochineal ; if we use the aluminous mordant, the cloth will acquire a crimson colour ; but the oxyde of iron produces with it a black. In dyeing, then, it is not only necessary to procure a mordant which has a sufficiently strong affinity for the colouring matter and the cloth, and a colouring matter which possesses the wished-for colour in perfection, but we must procure a mordant and a colouring matter of such a nature, that when combined together, they shall possess the wished-for colour in perfection. It is evident too, that a great variety of colours may be pro- duced with a single dye stuff*, provided we can change the mordant sufficiently. All those colours to which the dyers give the name of compound, are in fact two different colours applied to the cloth at once. Thus cloth gets a green colour, by being first dyed blue, and then yellow. The colours denominated by dyers simple, because they are the foundation of all their other processes, are four ; namely, blue, yellow, red, and black. To these they usually add a fifth, under the name of root, or brown colour. To dye Blue, — The only colouring matters employed in dyeing blue are woad and indigo. Wool and silk are often dyed blue by the sulphate of indigo ; but it can scarcely be applied to cotton and linen, because the affinity of these substances for indigo is not great enough to enable them readily to decompose the sulphate. The colour given by sulphate of indigo is exceedingly beautiful : it is known by the name of Saxon blue. One part of indigo is to be dissolved in four parts of concentrated sulphuric acid ; to the solution one part of dry carbonate of potass is to be added, and then it is to 60 THE SCHOOL OF USEFUL ARTS. be diluted with eight times its weight of water. The cloth must be boiled for an hour in a solution, containing five parts of alum and three of tartar for every thirty - two parts of cloth. It is then to be thrown into a water bath, containing a greater or smaller proportion of the diluted sulphate of indigo, according to the shade which the cloth is intended to receive. In this bath it must be boiled till it has acquired the wished-for colour. Silk is dyed of a light blue colour, by a ferment of six parts of bran, six of indigo, six of potass, and one of madder. To dye silk of a dark blue, it must previously receive what is called a ground colour ; archil is used for this purpose. Cotton and linen are dyed blue by a solution of one part of indigo, one part of green sulphate of iron, and two parts of quicklime. To dye Yellow , — The principal colouring matters for dyeing yellow are weld, fustic, and quercitron bark. Wool may be dyed yellow by the following process : let it be boiled for an hour or more with about one-sixth of its weight of alum, dissolved in a sufficient quantity of water. It is then to be plunged, without being rinsed, into a bath of warm water, containing in it as much quercitron bark as equals the. weight of the alum employed as a mordant. The cloth is to be turned through the boiling liquid till it has acquired the in- tended colour. Then a quantity of clean powdered chalk, equal to the hundredth part of the weight of the cloth, is to be stirred in, and the operation of dyeing continued for eight or ten minutes longer. By this method a pretty deep and lively yellow may be given, fully as permanent as weld yellow. For very bright orange or golden yellow, it is neces- sary to have recourse to the oxide of tin as a mordant. For producing bright golden yellows, some alum must be added along with the tin. In order to give the yellow that delicate green shade so much admired for certain purposes, tartar must be added in different proportions according to the shade. By adding a small proportion of cochineal, the colour may be raised to a fine orange, or even an aurora. THE SCHOOL OF USEFUL ARTS. 61 Silk may be dyed different shades of yellow, either by weld or quercitron bark, but the last is the cheapest of the two. 'i he proportion should be from one or two parts of bark to twelve parts of silk, according to the shade. The bark, tied up in a bag, should be put into the dyeing vessel, while the water which it contains is cold ; and when it has acquired the heat of about 100°, the silk having been previously alumed, should be dipped in, and continued till it assumes the wished-fur colour. Whim the shade is required to be deep, a little chalk or pearl ash should be added towards the end of the operation. Cotton and //wen are dyed yellow as follows : The mordant should be acetite of alumine, prepared by dissolving one part of acetite of lead, and three parts of alum, in a sufficient quantity of water. This solution should be heated to the temperature of 100°, the cloth should be soaked in it for two hours, then wrung out and dried. The soaking may be repeated, and the cloth again dried as before. It is then to be barely wetted with lime water, and afterwards dried. The soaking in the acetite of alumine may be again repeated, and if the shade of yellow is required to be very bright and durable, the alternate wetting with lime water and soaking in the mordant may be repeated three or four times. By this contrivance a sufficient quantity of alumine is combined with the cloth, and the combination is ren- dered more permanent by the addition of lime. The dyeing bath is prepared by putting twelve or eighteen parts of quercitron bark (according to the depth of the shade required), tied up in a bag, into a sufficient quan- tity of cold water. Into this bath the cloth is to be put, and turned round in it for an hour, while its temperature is gradually raised to about 120°; it is then to be brought to a boiling heat, and the cloth allowed to re- main in it after that only a few minutes. If it be kept long at a boiling heat, the yellow acquires a shade of brown. Nankeen yellow is obtained by a solution of the red sulphate of iron, which is combined with the cloth by carbonate of potass. F 6'Z THE SCHOOL OF USEFUL ARTS. To dye Red . — The colouring matters employed for dyeing red are kermes, cochineal, archil, madder, carthamus, Brazil-wood, lac, and logwood. Wool may be died red with madder or archil, but these are used only for coarse woollen stuffs. The stuffs are first boiled for some hours in alum and tartar, and then wrung out. After remaining some days, they are boiled in a decoction of madder. Scarlet is the most splendid of all reds, but is of dif- ferent shades, like other colours. AluminefWas formerly used as a mordant for fixing the cochineal which is used for dyeing red, but nitro-muriate of tin is now employed for this purpose, as it gives a brighter colour to the cochineal. To dye woollen cloth scarlet, it is first boiled in a bath of pure tartar, to which a little cochi- neal has been added, and also nitro-muriate of tin. After this it is well washed, and then subjected to a second bath of cochineal, which is called the reddening. Sometimes they do not change the bath, but add the reddening to the first bath. As the red produced by cochineal alone is rather a crimson than a bright scarlet, to produce the latter it is necessary first to dye the cloth yellow, and after crimson, as a bright scarlet is a compsound of crimson and yellow. This is done by the use of fustic, turme- ric, or quercitron bark, in the first bath, to produce the yellow; the second bath is cochineal alone, which naturally gives a crimson tinge. When Crimson is the colour required to be dyed, the tin mordant is the best, but sometimes dyers use alum baths for this purpose, and then a decoction of cochineal. The addition of archil and potass to the cochineal renders the crimson darker, and gives it more bloom, but this is very fugacious. For paler crimsons, a por- tion of madder is substituted for part of the cochineal. Silk is usually dyed red with cochineal or carthamus, and sometimes with Brazil-wood. Kermes does not answer for silk ; madder is scarcely ever used for that purpose, because it does not yield a colour bright enough. Archil is employed to give silk a bloom ; but it is scarcely used by itself, unless when the colour wanted is lilac. THE SCHOOL OF USEFUL ARTS. 63 Silk may be dyed crimson by steeping it in a solution of alum, and then dyeing it in the usual way in the cochineal bath. The colours known by the names of poppy y cherry, rose, and flesh colour, are given to silk by means of carthamus. The process consists merely in keeping the silk, as long as it extracts any colour, in an alkaline solution of carthamus, into which as much lemon juice as gives it a fine cherry colour has been poured. Silk cannot be dyed a full scarlet; but a colour ap- proaching to scarlet may be given it, by first impreg- nating the stuff with murio-sulphate of tin, and after- wards dyeing it in a bath composed of four parts of cochineal, and four parts of quercitron bark. To give the colour more body, both the mordant and the dye may be repeated. A colour approaching scarlet may be also given to silk by first dyeing it crimson, then dyeing it with carthamus, and lastly yellow without heat. Cotton wcLfi Linen are dyed red with madder. The process was borrowed from the east. Hence the colour is often called Adrianople, or Turkey-red. The cloth is first impregnated with oil, then with galls, and lastly with alum. It is then boiled for an hour in a decoction of madder, which is commonly mixed with a quantity of blood. After the cloth is dyed, it is plunged into a soda lye, in order to brighten the colour. The red given by this process is very permanent, and when properly conducted, it is exceedingly beautiful. The whole difficulty consists in the application of the mordant, which is by far the most complicated employed in the whole art of dyeing. Cotton may be dyed scarlet by means of murio- sulphate of tin, cochineal, and quercitron bark, used as for silk, but the colour is too fading to be of any value. To dye Black, — The substances employed to give a black colour to cloth, are red oxj^de of iron and tan. These two substances have a strong affinity for each other; and when combined, assume a deep black colour, not liable to be destroyed by the action of air or light. Cloth, before it receives a black colour, is usually F 2 64 THE SCHOOL OF USEFUL ARTS. dyed blue : this renders the colour much fuller and finer than it would otherwise be. If the cloth be coarse, the blue dye may be too expensive ; in that case a brown colour is given by means of walnut peels. Wool is dyed black by the following process: it is boiled for two hours in a decoction of nut galls, and afterwards kept for two hours more in a bath composed of logwood and sulphate of iron, at a scalding heat, but not boiled. During the operation, it must be frequently exposed to the air 5 because the green oxide of iron, of which the sulphate is composed, must be converted into red oxide by absorbing oxygen, before the cloth can acquire a proper colour. The common proportions are, five parts of gall, five of sulphate of iron, and thirty of logwood, for every hundred of cloth. A little acetite of copper is commonly added to the sulphate of iron, be- cause it is thought to improve the colour. Silk is dyed nearly in the same manner. It is capable of combining with a great deal of tan : the quantity given is varied at the pleasure of the artist, by allowing the silk to remain a longer or shorter time in the decoc- tion. Linen and Cotton are not easy to dye of a full black. The cloth, previously dyed blue, is steeped for twenty- four hours in a decoction of nut galls. A bath is pre- pared, containing acetite of iron, formed by saturating acetous acid with brown oxide of iron : into this bath the cloth is put in small quantities at a time, wrought with the hand for a quarter of an hour, then wrung out, and aired again *, next wrought in a fresh quantity of the bath, and afterwards aired. These alternate pro- cesses are repeated till the colour wanted is given. A decoction of alder bark is usually mixed with the liquor containing the nut galls. To dye Brown, — Brown, or fawn-colour, though in fact a compound, is usually ranked among the simple colours, because it is applied to cloth by a single pro- cess. Various substances are used for brown dyes. Walnut peels, or the green covering of the walnut, when first separated, they aie white internally, but soon assume a brown, or even a black colour, on expo- THE SCHOOL OF USEFUL ARTS. 65 sure to the air. They readily yield their colouring matter to water. They are usually kept in large casks, covered with water, for above a year before they are used. To dye wool brown with them, nothing more is necessary, than to steep the cloth in a decoction of them till it has acquired the wished-for colour. The depth of the shade is proportional to the strength of the decoc- tion. The root of the walnut tree contains the same co- louring matter, but in smaller quantity. The bark of the birch also, and many other trees, may be used for the same purpose. It is very probable that the brown colour- ing matter is in these vegetable substances combined with tan. This is certainly the case in shumac, which is often employed to produce a brown. This combination explains the reason why no mordant is necessary ; the tan has a strong affinity for cloth, and the colouring matter for the tan. The dye stuif and the mordant are already, in fact, combined together. To dye Compound Colours. — Compound colours are produced by mixing together two simple ones, or, which is the same thing, by dying cloth first one simple colour, and then another. These colours vary to infinity, according to the proportions of the ingredients employed. Mixtures of Blue and Yellow . — This forms green, which is distinguished by dyers into a variety of shades, according to the depth of the shade, or the prevalence of either of the component parts. Thus we have sea^ greeuy grass-green^ pea-green^ ^c. Wool, Silk, and Linen, are usually dyed green, by giving them first a blue colour, and afterwards dyeing them yellow ; because, when the yellow is first given, several inconveniences follow : the yellow partly sepa- rates again in the blue vat, and communicates a green colour to it, and thus renders it useless for every other purpose except dyeing green. Any of the usual pro- cesses for dyeing blue and yellow may be followed, taking care to proportion the depth of the sl»ades to that of the green required. When sulphate of indigo is employed, it is usual to mix all the ingredients to- gether, and to dye the cloth at once; this produces f3 66 the school of useful arts. what is known by the name of Saxon, or English green. 3Iixturcs of Blue and Red. — These form different shades of violet^ purple, and lilac. Wool is generally first died blue, and afterwards scarlet, in the usual manner. By means of cochineal mixed with sulphate of indigo, the process may be performed at once. Silk is first dyed crimson by means of chochineal, and then dipped into the indigo vat. Cotton and linen are first dyed blue, then galled, and soaked in a decoction of logwood ; but a more permanent colour is given by means of oxide of iron. Mixtures of Yellow and Red. — This produces orange. When blue is combined with red and yellow on cloth, the resulting colour is olive. Wool may be dyed orange by first dyeing it scarlet, and then yellow. When it is dyed first with madder, the result is cinnamon colour. Silk is dyed orange by means of carthamus ; a cin- namon colour by logwood, Brazil wood, and fustic mixed together. Cotton and Linen receive a cinnamon colour by means of weld and madder; and an olive colour by being passed through a blue, yellow, and then a madder bath. Mixtures of Black with other Colours. — These con- stitute greys, drabs, and browns. If cloth be previously combined with brown oxide of iron, and afterwards dyed yellow with quercitron bark, the result will be a drab of different shades, according to the proportion of mordant employed. When the proportion is small, the colour inclines to olive or yellow ; on the contrary, the drab may be deepened or saddened, as the dyers term it, by mixing a little shumac with the bark. STAINING WOOD. To stain Wood Yellow. — Take any white wood, and brush it over several times with the tincture of turmeric root, made by putting an ounce of turmeric, ground to powder, to a pint of spirit, and after they have stood THE SCHOOL OF USEFUL ARTS. 67 for some days, straining off the tincture. If the yellow colour be desired to have a reddish cast, a little dragon's blood must be added. A cheaper, but less strong and bright yellow, is by the tincture of French berries made boiling hot. Wood may also be stained yellow by means of aqua- fortis, which will sometimes produce a very beautiful yellow colour, but at other times a browner. Care must be taken, however, that the aquafortis be not too strong, otherwise a blackish colour will be the result. To stain Wood Red , — For a bright red stain for wood, make a strong infusion of Brazil wood in stale urine, or water impregnated with pearl ashes, in the proportion of an ounce to a gallon ; to a gallon of either of which, the proportion of Brazil wood must be a pound, which being put to them, they must stand together for two or three days, often stiring the mixture. With this infu- sion strained, and made boiling hot, brush over the wood to be stained till it appears strongly coloured ; then, while yet wet, brush it over with alum water made in the proportion of two ounces of alum to a quart of water. For a less bright red, dissolve an ounce of dragon's blood in a pint of spirits of wine, and brush over the wood w ith the tincture till the stain appears to be as strong as is desired ; but this is, in fact, rather lacquer- ing than staining. For a Pink or Rose Red, add to a gallon of the above infusion of Brazil wood two additional ounces of the pearl ashes, and use it as was before directed : but it is necessary, in this case, to brush the wood over with the alum water. By increasing the proportion of pearl ashes, the red may be rendered yet paler; but it is proper, when more than this quantity is added, to make the alum water stronger. To stain Wood Blue , — Wood may be stained blue by means either of copper or indigo. The method of staining blue with copper is as fol- lows : — Make a solution of copper in aquafortis, and brush it while hot several times over the wood; then make a solution of pearl ashes in the proportion of two 68 THE SCHOOL OF USEFUL ARTS. ounces to a pint of water, and brush it hot over the wood stained with the solution of copper, till it be of a perfectly blue colour. To stain Wood Green, — Dissolve verdigrise in vinegar, or crystals of verdigrise in water, and with the hot solution brush over the wood till it be duly stained. To stain Wood Purple. — Brush the wood to be stained several times with a strong decoction of logwood and Brazil, made in the proportion of one pound of the logwood, and a quarter of a pound of the Brazil, to a gallon of water, and boiled for an hour or more. When the wood has been brushed over till there be a sufficient body of colour, let it dry, and then be slightly passed over by a solution of one drachm of pearl ashes in a quart of water. This solution must be carefully used, as it will gradually change the colour from a brown red, which it will be originally found to be, to a dark blue purple, and therefore its effect must be restrained to the due point for producing the colour desired. To stain Wood a Mahogany Colour, — The substances used for staining mahogany are madder, Brazil wood, and logwood; each of which produce reddish brown stains, and they must be mixed together in such pro- portions as will produce the tint required. To stain Wood Black. — Brush the wood several times over with a hot decoction of logwood. Then having prepared an infusion of galls, by putting a quarter of a pound of powdered galls to two quarts of water, and setting them in the sunshine, or any other gentle heat, for three or four days, brush the wood over three or four times with it, and it will be of a beautiful black. It may be polished with a hard brush and shoemakers’ black wax. INK MAKING. Inks are fluid compounds intended to form characters, or other kinds of figures, on proper grounds of paper, parchment, or such other substances as may be fit to receive them. THE SCHOOL OF USEFUL ARTS. 69 Best Black Writing Ink , — The receipt given by M. Ribonecourt is as follows : — Take eight ounces of Aleppo galls, in coarse powder; four ounces of log- wood, in thin chips ; four ounces of sulphate of iron (green copperas); three ounces of gum arabic, in pow- der; one ounce of sulphate of copper (blue vitriol); and one ounce of sugar-candy. Boil the galls and log- wood together in twelve pounds of water for one hour, or till half the liquid has been evaporated ; strain the decoction through a hair sieve, or linen cloth, and then add the other ingredients. Stir the mixture till the whole is dissolved, more especially the gum; after which, leave it to subside for twenty-four hours. Then decant the ink, and preserve it in bottles of glass or stone well corked. To make One Gallon of Black Writing Ink , — Into a glazed stone jar or pitcher put one pound of Aleppo galls, slightly bruised; then add one gallon of rain water, nearly of a boiling heat; let these stand together for fourteen days upon the kitchen hearth, or moderately warm ; after that time add four ounces of green cop- peras or sulphate of iron, four ounces of logwood chips or shavings, one ounce of alum, one ounce of sugar- candy, and four ounces of gum arabic or gum senega!. Let the whole remain ten or twelve days longer in a mode- rate heat, the mouth of the vessel slightly covered with paper. Stir the ingredients well with a stick twice a day during the whole time; then strain off the ink through linen or flannel, bottle it, pour a little brandy on the top of the ink in each bottle, then cork them well, and keep them for use in a place of temperate heat. This ink may be depended upon as excellent, durable, and preserving the writing all of a deep black. The best galls for the purpose are those which are dark coloured, heavy, and free from grub holes. Red Writing Ink , — Take of the raspings of Brazil wood a quarter of a pound, and infuse them two or three days in vinegar. Boil the infusion for an hour over a gentle fire, and afterwards filter it while hot. Put it again over the fire, and dissolve in it, first, half 70 THE SCHOOL OF USEFUL ARTS. an ounce of gum arabic, and afterwards of alum and white sugar each half an ounce. Another Method, — Take a quarter of a pound of the best Brazil wood (get it in the log if possible, and rasp or shave it), one ounce of cream of tartar, and one ounce of alum ; boil these ingredients in a quart of clear water till half is consumed, then add to the ink, when filtered hot, one ounce of gum arabic and one ounce of fine sugar. A little salt added will prevent it from becoming mouldy. To prevent Ink from moulding, — Half a dozen cloves, bruised with gum arabic, are to be put into the bottle. If a very fine ink is wanted, white wine, or vinegar and water, should be used instead of water alone. To make Indian Ink, — Put six lighted wicks into a dish of oil ; hang an iron or tin concave cover over it, so as to receive all the smoke ; when there is a suffi- cient quantity of soot settled to the cover, then take it off gently with a feather upon a sheet of paper, and mix it up with gum tragacanth to a proper consistence. The clearest oil makes the finest soot, consequently the best ink. To make China /w^.-r-Take dried black horse-beans, burn them to a powder, mix them up with gum arabic water, and bring them to a mass ; press it well, and let it dry. Substitute for Indian Ink, — Boil parchment slips, or cuttings of glove leather, in water, till it forms a size, which, when cool, becomes of the consistence of jelly; then having blackened an earthen plate, by holding it over the flame of a candle, mix up, with a camers-hair pencil, the fine lamp black thus obtained, with some of the above size, while the plate is still warm. This black requires no grinding, and produces an ink of the very best colour, which works as freely with the pencil, and is as perfectly transparent as the best Indian ink ; it possesses the advantage of furnishing artists with a substitute for that article, which may be prepared THE SCHOOL OF USEFUL ARTS. 71 in situations where it might be difficult to obtain the ink itself. German Black for Printers , — Take the lees of port wine, dry and burn them ; add thereto good ivory black, the stones of cherries, plums, or other stone fruit, burnt in close vessels, and fine soft charcoal made from burnt willow ; grind the whole well together into one mass, from which the best printing ink may be formed. Permanent Writing Ink , — As common writing ink is susceptible of being eftaced by oxygenated muriatic acid, and as the knowledge of this fact may be abused to very fraudulent purposes, the following composition for inks, absolutely indestructible, is recommended to the notice of the curious : — Boil one ounce of Brazil wood, and three ounces of nut galls, in forty-six ounces of water, till they shall be reduced to thirty ounces in all. Pour this decoction, while it is yet hot, upon half an ounce of sulphate of iron, a quarter of an ounce of gum arabic, and a quarter of an ounce of while sugar. After these substances are dissolved, add to the solution one ounce and a quarter of indigo, finely pulverized, with three quarters of an ounce of lamp-black, very pure, and a quarter of an ounce of smoke black, previously dissolved in one ounce of the best brandy. The following receipt is still more simple — Boil one ounce of Brazil wood with twelve ounces of water and half an ounce uf alum; continue the ebullition till the liquid mixture shall have been reduced to eight ounces ; then add an ounce of the black oxide of manganese, which has been reduced by decantation to extreme fine- ness, and, in mixture with it, half an ounce of gum arabic. The chief advantage of this ink (said to be proposed by Schever) is, that it is in part a printer's ink: the black oxide of manganese and the lamp black not being affected by acids, and the indigo in powder but slightly, so that they must be effaced by rubbing, or washing off, and not by solution. The ink, however, is not absolutely indestructible, nor equal to the common 72 THE SCHOOL OF USEFUL ARTS. iiulelible ink, which *nay he used on paper as well as silk, linen, and cotton cloths. Permanent Red Ink for marking Linen . — This useful preparation, which was contrived by the late learned and ingenious Dr. Sraellie of Edinburgh, who was originally a printer in that city, may be used either with types, a hair pencil, or even wdth a pen. Take half an ounce of vermilion, and a dram of salt of steel ; let them be finely levigated with linseed oil to the thickness or limpidity required for the occasion. Tliis has not only a very good appearance ; but will be found perfectly to resist the effects of acids, as well as of all alkaline leys. It may be made of other colours, by substituting the proper articles instead of vermilion. Sympathetic Inks . — Sympathetic inks are such as do not appear after they are written with, but which may be made to appear at pleasure. A variety of substances have been used for this purpose. We shall describe the best of them. 1st. Dissolve some sugar of lead in water, and write with the solution. When dry no writing will be visible. When you want to make it appear, wet the paper with a solution of alkaline sulphuret (liver of sulphur), and the letters will immediately appear of a brown colour. Even exposing the writing io the vapours of these solutions will render it apparent. 2d. Write with a solution of gold in aqua regia, and let the paper dry gently in the shade. Nothing will ap- pear but draw a sponge over it wetted with a solution of tin in aqua regia, the writing will immediately appear of a purple colour, 3d. Write with an infusion of galls ; and when you wish the writing to appear, dip it into a solution of green vitriol ; the letters will appear black. 4th. Write with diluted sulphuric acid, and nothing will be visible. To render it so, hold it to the fire, and the letters will instantly appear black. 5th. Juice of lemons or onions, a solution of sal ammoniac, green vitriol, &c, will answer the same pur- pose, though not so easily or with so little heat. THE SCHOOL OF USEFUL ARTS. 73 Cth. Green Sympathetic Ink . — Dissolve cobalt in nitro nuriatic acid, and write with the solution. The letters tvill be invisible till held to the fire, when they will ap- pear green, and will disappear completely again when 'emoved into the cold. In this manner they may be made to appear and disappear at pleasure. A very pleasant experiment of this kind, is to make a Irawing representing a winter scene, in which the trees ippear void of leaves, and to put the leaves on with this sympathetic ink ; then, upon holding the drawing near to the fire, the leaves will begin to appear in all the verdure of spring, and will very much surprise those who are not in the secret. 7th. Blue Sympathetic Ink . — Dissolve cobalt in nitric acid; precipitate the cobalt by potass; dissolve this precipitated oxyde of cobalt in acetic acid, and add to the solution one-eighth of common salt. This will form a sympathetic ink, that, when cold, will be invisible, but will appear blue by heat. REMOVING OF STAINS. To erase Ink just spilled . — If the ink be spilled on a ruffle, or apron, &c. while you have it on, let one hold the spotted part between his two hands over a basin and rub it, while another pours water gradually from a decan- ter upon it, and let a whole pitcherful be used if neces- sary ; or if the ruffle, apron, &c. be at liberty, let it be dipped into a basin filled with water, and there squeezed and dipped in again, taking care to change the water in abundance every two or three squeezes. If the ink be spilled on a green table carpet, it may immediately be taken out with a teaspoon so entirely, that scarcely any water at all shall be wanted afterwards, provided it was only that instant spilled, as the down of the cloth pre- vents the immediate soaking in of the ink, or of any other liquor (except oil) ; but if it have lain some time, be the time ever so long, provided the place be still wet, by pouring on it fresh clean water by little and little at a time, and gathering it up again each time with a spoon, G 74 THE SCHOOL OE USEFUL ARTS. pressing hard to squeeze it out of the cloth into the spoon, it will at last be brought to its natural colour. To remove Grease Spots . — Grease spots in cloth nriay be removed by using soap and water with a tooth or nail brush, and afterwards wiping off the lather with the wet comer of a towel. Essence of lemon, or pure spirit of turpentine, will remove pitch from cloth, &c. Bleaching Prints^ and printed Books . — An applica- tion has been made of the new mode of bleaching, to the whitening of books and prints that have been soiled by smoke and time. Simple immersion in oxygenated muriatic acid, letting the article remain in it a longer or shorter space of time, according to the strength of the liquid, will be sufficient to whiten an engraving. If it be required to whiten the paper of a bound book, as it is necessary that all the leaves should be moistened by the acid, care must be taken to open the book well, and to make the boards rest on the edge of the vessel, in such a manner that the paper alone be dipped in the liquid : the leaves must be separated from each other, in order that they may be equally moistened on both sides. The liquor assumes a yellow tint, and the paper be- comes white in the same proportion ; at the end of two or three hours, the book may be taken from the acid liquor, and plunged into pure water, with the same care and pre- caution as recommended in regard to the acid liquor, that the water may exactly touch the two surfaces of each leaf. The water must be renewed every hour, to extract the acid remaining in the paper, and to dissipate the dis- agreeable smell. By following this process, there is some danger that the pages will not be all equally whitened, either because the leaves have not been sufficiently separated, or because the liquid has had more action on the front margins than on those near the binding. On this account, the best way is to destroy the binding entirely, that each leaf may receive an equal and perfect immersion ; and this is the second process recommended by M. Chaptal. “ They begin,'’ says he, “ by unsewing the book, and separating it into leaves, which they place in cases formed THE SCHOOL OF USEFUL ARTS. 75 in a leaden tub, with very thin slips of wood, or glass, so that the leaves, when laid flat, are separated from each other by intervals scarcely sensible. The acid is then poured in, making it fall on the sides of the tub, in order that the leaves may not be deranged by its motion. When the workman judges, by the whiteness of the paper, that it has been sufficiently acted upon by the acid, it is drawn off by a cock at the bottom of the tub, and its place is supplied by clear fresh water, which weakens and carries off the remains of the acid, as well as the strong smell. The leaves are then to be dried, and after being pressed, nmy be again bound up. “ The leaves may be placed also vertically in the tub ; and tliis position seems to possess some advantage, as they will be less liable to be torn. With this view I con- structed a wooden frame, which I adjusted to the proper height, according to the size of the leaves which I wished to whiten. This frame supported very thin slips of wood, leaving only the space of half a line between them. I placed two leaves in each of these intervals, and kept them fixed in their place by two small wooden wedges, which I pushed in between the slips. When the paper was whitened, I lifted up the frame with leaves, and plunged them in cold water, to remove the remains of the acid as well as the smell : this process I prefer to the other. “ By this operation books are not only cleaned, but the paper acquires a degree of whiteness superior to what it possessed when first made. The use of this acid is attended also with the valuable advantage of destroying ink spots. This liquor has no action upon spots of oil or animal grease 5 but it has been long known that a weak solution of potass will effectually remove stains of that kind. When I had to repair prints so torn that they exhibited only scraps pasted upon other paper, I was afraid of losing these fragments in the liquid, because the paste became dissolved. In such cases 1 inclosed the prints in a cylindric glass vessel, which I inverted on the water in which I had put the mixture proper for extri- cating the oxygenated muriatic acid gas. This vapour, by filling the whole inside of the jar, acted upon the g2 76 THE SCHOOL OF USEFUL ARTS. print, extracted the grease as well as ink spots, and the fragments remained pasted to the paper.” Easy Method of preparing the Oxygenated Muriatic Acid. — ^To oxygenate the muriatic acid, nothing is neces- sary but to dilute it, and mix it in a very strong glass vessel with manganese, in such a manner that the mixture may nOt occupy the whole contents of the glass. Air bubbles are formed on the surface of the liquor ; the empty space becomes filled with a greenish vapour ; and at the end of some hours the acid may be farther diluted with water, and then used. It has an acid taste, and possesses all the virtues of the oxygenated muriatic acid. This process may be followed when there is not time to set up an apparatus for distilling, in order to procure the oxygenated acid. Method of bleaching Straw. — Dip the straw in a solu- tion of oxygenated muriatic acid, saturated with potass. (Oxygenated muriate of lime is much cheaper.) The straw is thus rendered very white, and its flexibility is encreased. To remove Iron Stains. — ^These may be occasioned by ink stains, which, on the application of the soap, are changed into iron stains, or by the direct contact of rusted iron. They may be removed by diluted muriatic acid, or by citric or oxalic acid dissolved in water. When suffered to remain long on cloth, they become extremely difficult to take out, because the iron, by repeated moistening with water, and exposure to the air, acquires such an addition of oxygen, as renders it insoluble in acids. It has been found, however, that even these spots may be discharged, by applying first a solution of an alkaline sulphuret, which must be well washed from the cloth, and afterwards a liquid acid. The sulphuret, in this case, extracts part of the oxygen from the iron, and renders it soluble in diluted acids. To remove the Stains of Fi'uit and IFiwc.— These are best removed by a watery solution of the oxygenated muriatic acid, or by that of oxygenated muriate of potass or lime, to which a little sulphuric acid has been added. The stained spot may be steeped in one of these solutions THE SCHOOL OF USEFUL ARTS. 77 till it is discharged ; but the solution can only be applied with safety to white goods, because the uncombined oxygenated acid discharges all printed and dyed colours. A convenient mode of applying the oxygenated acid, easily practicable by persons who have not the apparatus for saturating water with the gas, is as follows : — Put about a table>spoonful of muriatic acid (spirit of salt) into a teacup, and add to it about a tea>spoonful of powdered manganese ; then set this cup in a larger one filled with hot water ; moisten the stained spot with water, and expose it to the fumes that arise from the tea- cup. If the exposure be continued a sufficient length of time, the stain will disappear. To remove Spots of Grease from Cloth. — Spots of grease may be removed by a diluted solution of potass, but this must be cautiously applied, to prevent the injury to the cloth. Stains of white wax, which sometimes fall upon the clothes from wax candles, are removable by spirits of turpentine, or sulphuric ether. The marks of white paint may also be discharged by the last-mentioned agents. To discharge Grease from Books, Prints, or Paper . — After having gently warmed the paper that is stained with grease, wax, oil, or any other fat body, take out as much as possible of it by means of blotting paper ; then dip a small brush in the essential oil of turpentine, heated almost to ebullition (for when cold it acts only very weakly), and draw it gently over both sides of the paper, which must be carefully kept warm. This operation must be repeated as many times as the quantity of the fat body imbibed by the paper, or the thickness of the paper, may render necessary. When the greasy substance is entirely removed, recourse may be had to the following method to restore the paper to its former whiteness, which is not completely restored by the first process. Dip another brush in highly rectified spirit of wine, and draw it, in like manner, over the place which was stained, and par- ticularly round the edges, to remove the border that would still present a stain. By employing these means with proper caution, the spot will totally disappear, the paper will resume its original whiteness, and if the pro- 78 THE SCHOOL OF USEFUL ARTS. cess has been employed on a part written on with common ink, or printed with printers’ ink, it will experience no alteration. Portable Ballsy for removing Spots from Clothes in generaL — Take fullers’-earth, perfectly dried, so that it crumbles into powder; moisten it with the clear juice of lemons, and add a small quantity of pure pearl ashes; then work and knead the whole carefully together, till it acquires the consistence of a thick elastic paste ; form it into convenient small balls, and expose them to the heat of the sun, in which they ought to be completely dried. In this state they are fit for use in the manner following : — First, moisten the spot on your clothes with water, then rub it with the ball just described, and suffer it again to dry in the sun : after having washed the spot with pure water, it will entirely disappear. Expeditious Method of taking out Stains from Scarlet y or Velvet. — ^Take soap wort ; bruise it, strain out its juices, and add to it a small quantity of black soap. Wash the stain with this liquor, suffering it to dry be- tween whiles, and by this method the spots will in a day or two entirely disappear. To take Stains of Grease from Woollen or Silk . — Three ounces of spirits of wine, three ounces of French chalk, powdered, and five ounces of pipe clay. Mix the above ingredients, and make them up in rolls about the length of a finger. It is to be applied by rubbing on the spot either dry or wet, and afterwards brushing the place. MISCELLANEOUS RECEIPTS. To make Phosphoric Oil. — Put one part of phosphorus into six of olive oil, and digest them over a sand heat. The phosphorus will dissolve. It must be kept well corked. This oil has the property of being very luminous in the dark, and yet it has not sufficient heat to burn any thing. If rubbed on the face and hands, taking care to shut the eyes, the appearance is most hideously frightful ; all the parts with which it has been rubbed appear to be covered THE SCHOOL OF USEFUL ARTS. 79 with a very luminous lambent flame of a bluish colour, and the mouth and eyes appear in it as black spots. There is no danger attending this experiment. The light of it is sufficient to shew the hour of the night on a watch, by bolding it close to the bottle when it is un- stopped. A Test for Lead, Copper^ ^c. in Wines. — Lead and copper being sometimes used to amend the taste of wines, and these metals being of a very poisonous quality, a test that shall detect this is of great value. The following test is the discovery of Mr. Hanhemann, and is found to an- swer perfectly. Equal parts of oyster-shells and crude sulphur are to be kept in a white heat for a quarter of an hour, and, when cold, this is to be mixed with an equal quantity of acidulous tartrite of potass, and put into a strong bottle with common water for an hour, and then decanted into bottles holding an ounce each, with twenty drops of muriatic acid in each. This liquor precipitates the least quantities of lead, copper, &c. from wines, in very sensible black precipitate. To make BrasSy and other Alloys of Copper. — Brass is made by fusing together lapis calaminaris (which is an ore of zinc) and copper. Tombac is formed by melting together twelve parts of copper with three of zinc. Gun-metal consists of nine parts of copper and one of tin. Bell-metal is copper alloyed with one-sixth of tin. A smaller proportion of tin is used in making church bells than clock bells, and a little zinc is added for the bells of repeating-watches, and other small bells. Cock- metal is made with copper alloyed with zinc and lead. The gold coins of this country are composed of eleven parts of gold and one of copper. Standard silver contains fifteen parts of silver and one of copper. To make a Phosphoric Fire Bottle. — Take a very small phial, and put into it a bit of phosphorus as large as a pea, and fill up the bottle with lime. Fix an iron vessel, as a shovel, for instance, with common sand, and put it 80 THE SCHOOL OF USEFUL ARTS. over the fire. Set the phial in this sand, having loosely stopped it with a cork. Stir about the ingredients with a wire, and mix them together, taking care that the phcs* phorus does not catch fire by too great an access of air. Keep the bottle in the sand till the phosphorus is thoroughly incorporated with the lime, when it will be of a reddish yellow. This bottle is extremely convenient for procuring an instantaneous light in the dark. For this purpose, no- thing more is necessary than to uncork the bottle, and to introduce a brimstone match, stirring it about a little, by which it will catch fire and light. The bottle must be always kept carefully corked, and opened as seldom as possible. A more durable kind may be made by uniting together one part of sulphur with eight of phosphorus. When this is used, a match is introduced into it, and then rubbed upon a bit of cork. To make Fulminating Powder, — ^Triturate in a warm mortar three parts, by weight, of nitre, two of mild vegetable alkali (carbonate of potass), and one of flowers of sulphur. A few grains of this laid upon a knife, and held over the candle, first fuses, and then explodes with a loud report. A drachm of it put into a shovel, and held over the fire, makes a noise as loud as a cannon, and indents the shovel as if it had received a violent blow. To make the Arhor D lance ^ or Tree of Diana. — ^Take half an ounce of fine silver, and two drachms of mercury, and dissolve them separately in a quantity of aquafortis, no longer than necessary. When the solutions are per- fectly made, mix them together, and pour them into a pint of common water, and stir it about, that the whole may be well mixed. Keep this preparation in a bottle well corked. In a glass globe, or other vessel, put the quantity of a small nut of the amalgam of silver with mercury, and pour three or four ounces of the above liquor over it. After some hours there arise from the little globular amalgam small branches, that, by increasing, will form a beautiful kind of shrub, or tree of silver. To make a Tree of Silver on Glass. — Put a few drops of the solution of silver in aquafortis on a piece of glass. THE SCHOOL OF USEFUL ARTS. 81 9U(1 having formed a bit of copper or brass wire to repre- sent a tree with its branches, but flat, so as to lie upon the glass, lay it in the liquid, and let it remain for an hour or two. A beautiful vegetation will be perceived all round the wire, which will nearly be covered by it. This may be preserved by washing it very carefully with water, and putting another glass over it. To form a Tree of Lead, — Dissolve an ounce of sugar of lead in a quart of clear water, and put it into a ! glass decanter or globe. Then suspend in the solution, | near the top, a small piece of zinc of an irregular shape, ! Let it stand undisturbed for a day, and it will begin to shoot out into leaves, and apparently to vegetate. If left undisturbed for a few days, it will become extremely beautiful \ but it must be moved with great caution. Arbor MartiSy or Tree of Mars, — Dissolve iron filings in aquafortis moderately concentrated, till the acid is satu> rated *, then add to it gradually a solution of fixed alkali, commonly called oil of tartar per deliquium, A strong effervescence will ensue, and the iron, instead of falling to the bottom of the vessel, will afterwards rise, so as to cover the sides, forming a multitude of ramifications heaped one upon the other, which will sometimes pass over the edge of the vessel, and extend themselves on the outside with all the appearance of a plant. To whiten Silver by boiling. — Whitening of silver by boiling is one of the methods of parting cppoer from silver in the humid way. For this purpose, silver wrought in any shape is first ignited to redness, and afterwards boiled in a ley of muriate of soda, and acidulous tartrite of potass. By so doing, the copper is removed from the surface, and the silver receives a better appearance. To clean Goldy and restore its Lustre, — Dissolve a little sal-ammoniac in urine ; boil your soiled gold therein and it will become clean and brilliant. To blue Mourning Buckles^ Swords^ 4 *c. — ^Take a piece of grindstone and whetstone, and rub hard on the work, to take off the black scurf from it ; then heat it in the fire, and as it grows hot the colour changes by degrees, coming first to a light, then to a dark gold colour, and 8*2 THE SCHOOL OF USEFUL ARTS. lastly to a blue. Indigo and salad oil, ground together^ is also used, by rubbing the mixture on the work with a woollen cloth, while it is heating, leaving it to cool of itself. To make Glass Toys, — Prince Rupert’s drops are made, by letting drops of melted glass fall into cold water: the drop assumes by that means an oval form, with a tail or neck resembling a retort. These drops are said to have been first invented by Prince Rupert, and are therefore called by his name. They possess this singular property, that if a small portion of the tail is broken off, the whole bursts into powder, with an explosion 5 and a consider- able shock is communicated to the hand that grasps it. The Bologna or Philosophical Phial^ is a small vessel of glass, which has been suddenly cooled, open at the upper end, and rounded at the bottom. It is made so thick at the bottom, that it will bear a smart blow against a hard body, without breaking; but if a little pebble, or piece of flint, is let fall into it, it immediately cracks, and the bottom falls into pieces : but unless the pebble or flint is large and angular enough to scratch the surface of the glass, it will not break. To cut Glass. — Take a red hot shank of a tobacco pipe, lay it on the edge of your glass, which will then begin to crack, then draw the shank end a little gently before, and it will follow any way you draw your hand. To make Blacking,~-ln three pints of small beer put two ounces of ivory black, and one pennyworth of brown sugar. As soon as they boil, put a desert-spoonful of sweet oil, and then boil slowly till reduced to a quart. Stir it up with a stick every time it is used. Another method. — Two ounces of ivory black, one tea-spoonful of oil of vitriol, one table-spoonful of sweet oil, and two ounces of brown sugar; roll the same into a ball, and to dissolve it add half a pint of vinegar. Another method, — Take ivory black and brown sugar- candy, of each two ounces ; of sweet oil a table-spoonful; add gradually thereto a pint of vinegar, cold, and stir the whole tilt gradually incorporated. THE SCHOOL OF USEFUL ARTS. 83 Another method, — To one pint of vinegar add half an ounce of vitriolic acid, half an ounce of copperas, two ounces of sugar-candy, and two ounces and a half of ivory black : mix the whole well together. Another method. — Sweet oil, half an ounce 5 ivory black and treacle, of each half a pound ; gum arabic, half an ounce 5 vinegar, thee pints; boil the vinegar, and pour it hot on the other ingredients. Another Three ounces of ivory black, one ounce of sugar-candy, one ounce of oil of vitriol, one ! ounce of spirits of salts, one lemon, one table-spoonful of sweet oil, and one pint of vinegar. — First mix the ivory ! black and sweet oil together, then the lemon and sugar- candy, with a little vinegar to qualify the blacking ; then add your spirits of salts and vitriol, and mix them all well together. The last ingredients prevent the vitriol and salts from > injuring the leather, and add to the lustre of the blacking. j Another method, — Ivory black, two ounces ; brown sugar, one ounce and a half; sweet oil, half a table- spoonful. Mix them well, and then gradually add half a pint of small beer. Another method. — A quarter of a pound of ivory black, a quarter of a pound of moist sugar, a table-spoonf»»l of flour, a piece of tallow about the size of a walnut, and a small piece of gum arabic. Make a paste of the flour, and while hot put in the tallow, then the sugar, and afterwards mix the whole well together in a quart of water, and you will have a beautiful shining blacking. To make Blacking Balls for Shoes, — Mutton suet, four ounces ; bees’-wax, one ounce ; sugar-candy and gum arabic, one drachm each, in fine powder ; melt these well together over a gentle fire, and add thereto about a spoon- ful of turpentine, and ivory and lamp black sufficient to give it a good black ; while hot enough to run, you may make it into a ball, by pouring the liquor into a tin mould ; or let it stand till almost cold : you may mould it in what form you please by the hand. Celebrated Blacking Cake for Boots and Shoes. — Take one part of gum tragacanth, four parts of river water, 84 THE SCHOOL OF USEFUL ARTS. two parts of neats-foot, or some other softening Iubrt> eating oil, two parts of superfine ivory black, one part of Prussian blue in fine powder, or indigo, four parts of brown sugar-candy ; boil the mixture, and when the cora- positon is of a proper consistence, let it be formed into cakes of such a size that each cake may make a pint of liquid blacking. Chemical Liquid for Boot Tops, ^c. — Many of the liquids, sold under various denominations, for the purpose of cleaning and restoring the colour of boot tops, &c. are found very imperfectly to answer that purpose, and often to injure the leather. The following genuine receipt may be fully relied on, for actually producing this desirable effect, as well as for readily taking out grease, ink spots, and the stains occasioned by the juice of fruit, red port wine, &c. from all leather or parchment: — Mix in a phial one drachm of oxymuriate of potass with two ounces of distilled water ; and, when the salt is dissolved, add two ounces of muriatic acid. Then, shaking well together, in another phial, three ounces of rectified spirit of wine with half an ounce of the essential oil of lemon, unite the contents of the two phials, and keep the che- mical liquid thus prepared closely corked for use. This chemical liquid should be applied with a clean sponge, and dried in a gentle heat 5 after which, the boot tops may be polished with a proper brush, so as to appear like new leather. To clean Boot TopSy or any tanned Leather, — Boil one quart of milk ; let it stand till cold, then take one ounce of oil of vitriol, one ounce of spirits of salts ; shake them well together, and add one ounce of red lavender. You may put half a pint of vinegar, with the white of an egg beaten to a froth. To prevent Shoes from taking in One pint of drying oil, two ounces of yellow wax, two ounces of tur- pentine, and half an ounce of burgundy pitch, melted carefully over a slow fire. If new boots or shoes are rubbed with this mixture, either in the sunshine, or at some distance from the fire, with a sponge or soft brush, and the operation is repeated as often as they become dry, till the leather is fully saturated, they will be imper- THE SCHOOL OF USEFUL ARTS. 85 vious to wet, and will wear much longer, as well as acquiring a softness and pliability that will prevent the leather from ever shrivelling. Note, — Shoes or boots prepared as above ought not to be worn till perfectly dry and elastic, otherwise their durability would rather be prevented than increased. Economical method. — ^This simple and effectual remedy is nothing more than a little bees^wax and mutton suet, warmed in a pipkin, until in a liquid state 5 then rub some of it slightly over the edges of the sole where the stitches are, which will repel the w'et, and not in the least prevent the blacking from having the usual effect. To restore the Lustre of tarnished Gold or Silver Lace. — When gold or silver lace happens to be tarnished, the best liquor that can be used for restoring its lustre is spirits of wine ; it should be warmed before it is applied to the tarnished spot. This application will preserve the colour of the silk or embroidery. To clean Gilt Buckles or Toys. — Rub a little soap on a soft brush, dip the same in water, and gently brush the article you intend cleaning for a minute or two, then wash the same clean off, wipe it and place it near the fire till it is perfectly dry, then burn a piece of bread, pound it to a fine powder, and brush your articles with it as you do silver goods with whiting. Black Varnish for Straw or Chip Hats, — ^Take best black sealing-wax, half an ounce ; rectified spirit of wine, two ounces ; powder the sealing wax, and put it, with the spirit of wine, into a four-ounce phial ; digest them in a sand heat, or near a fire, till the wax is dissolved ; lay it on warm with a fine soft hair brush, before a fire, or iu the sun. It gives a good stiffness to old straw hats, and a beautiful gloss equal to new, and resists wet. If the hats are very brown they may be brqshed over with writing ink, and dried before the varnish is applied. Spirit of turpentine may probably be used in the place of the spirit of wine. To prevent Hats from being spotted after a Shower of Rain. — If the hat is wet from rain, or any other cause, shake it out as much as possible 5 then, with a clean linen 86 THE SCHOOL OF USEFUL ARTS. cloth or handkerchief, wipe the hat very carefully as well as you can, observing, that in so doing you keep the beaver flat and smooth, in the same direction as it was first placed, then with your hands fix it in the original shape, and hang it at a distance from the fire to dry. A few hours after, or the next morning, lay the hat on a table, and brush it round and round several times with a soft brush in the proper direction, and you will find your hat not in the least injured by the rain. If the gloss is not quite so high as you wish, take a flat iron, moderately heated, and pass the same two or three times gently over the hat ; brush it afterwards, and it will be nearly as handsome as when first sent home from the shop. Preventives against the Ravages of the Moth . — The most usual preventives against the injury occasioned by the moth are cedar wood and tobacco leaves. A piece of the former put into a box, if sufficiently large to emit its peculiar odour to whatever may be contained in it, will effectually preserve the cloth from injury j and it is well known, that in libraries where there are books bound with Russia leather, which is tanned with cedar, no moth or w orm will corrupt. It is common to put cedar shavings and chips into boxes, &c. which answer just as well as the wood itself. Tobacco leaves may be placed at certain intervals in the folds of a piece of wollen cloth ; and it is sufficient to examine them once in six months, in order to renew the leaves, if necessary. Easy Method of preventing Moths in Furs or Wool- lens . — Sprinkle the furs or woollen stuffs, as well as the drawers or boxes in which they are kept, with spirits of turpentine; the unpleasant scent of which will speedily evaporate, on exposure of the stuff’s to the air. Some persons place sheets of paper, moistened with spirits of turpentine, over, under, or between pieces of cloth, &c. and find it a very effectual method. To preserve FurSy WoollenSy — Many w'^oollen- tlrapers put bits of camphor, the size of a nutmeg, in papers, on different parts of their shelves in their shop ; THE SCHOOL OF USEFUL ARTS, 87 and as they brush their cloths every two, three, or four months, this keeps them free from moths ; and this should be done in boxes where furs are put. A tallow candle is frequently put within each muff when laid by. To keep Mothsy BeetleSy ^c. from Clothes. — Put a piece of camphor in a linen bag, or some aromatic herbs, in the drawers among linen or woollen clothes, and neither moth or worm will come near them. To purify Wool infested with Insects^ — ^The process of purification consists in putting into three pints of boiling water a pound and a half of alum, and as much cream of tartar, which are diluted in twenty-three pints more of cold water. The wool is then left immersed in this liquor during some days, after which it is washed and dried. After this operation it will no longer be subject to be attacked by insects. Chinese Method of rendering Cloth Water-proof — ^To one ounce of white wax, melted, add one quart of spirits of turpentine, which, when thoroughly mixed and cold, dip the cloth in and hang it up to dry. By this cheap and easy method, muslin, as well as the strongest cloths, will be rendered impenetrable to the hardest rains, without the pores being filled up, or any injury done, when the cloth is coloured. New Method of cleaning Silksy Woollensy and Cot- tons. — ^The following receipt is recommended as a good method of cleaning silk, woollen, and cotton goods, with- out damage to the texture or colour of the same : Grate raw potatoes to a fine pulp in clean water, and pass the liquid matter through a coarse sieve into another vessel of water ; let the mixture stand still till the fine white particles of the potatoes are precipitated ; then pour the mucilaginous liquor from the fecula, and pre- serve the liquor for use. The article to be cleaned should then be laid upon a linen cloth on a table, and having provided a clean sponge, dip the sponge into the potatoe liquor, and apply it to the article to be cleaned, till the dirt is perfectly separated ; then wash it in clean water several times. Two middle-sized potatoes will be suffi- cient for a pint of water. The white fecula will answer 88 THE SCHOOL OF OSEFUL ARTS. the purpose of tapioca, and make an useful nourishing^ food, with soup or milk, or serve to make starch and hair> powder. The coarse pulp, which does not pass the sieve, is of great use in cleaning worsted curtains, tapestry, carpets, or other coarse goods. The mucilaginous liquor will clean all sorts of silk, cotton, or woollen goods, with- out hurting or spoiling the colour; it may be also used in cleaning oil paintings, or furniture that is soiled. Dirtied painted wainscots may be cleansed by wetting a sponge in the liquor; then dipping it in a little fine clean sand, and afterwards rubbing the wainscot with it. Permanent Ink for marking Xiwew.— *Take of lunar caustic one dram; weak solution, or tincture of galls, two drams. The cloth must be firs^ wetted with the fol- lowing liquid, viz. salt of tartar, one ounce ; water, one ounce and an half; and must be perfectly dry before any attempt is made to write upon it. 89 INDEX. Bronzing - Cementing Dyes - - - Gilding House-painting Ink-making - — Permanent Sympathetic - Japanning Lacquering - Miscellaneous Receipts Oil Colours - Painting in Varnish Silvering Soldering Stain-removing Tinning Varnish Spirit Oil - Water-colours Wood-staining Page - 16 - 44 - 55 - 3 - 27 . 68 - 71 - 72 - 20 - 17 - 78 . 30 - 33 - 11 - 16 - 73 - 15 - 34 - 35 - 36 . 28 - 66 Printed hy William Cole, 10 , Neivgate-street, THE SCHOOL OF FINE ARTS: CONTAINING AMPLE DIRECTIONS EVERY MODE OF PAINTING, IN OIL AND WATER COLOURS ; FOR 0ngraDin0 anu Copper plate printing; AND FOR MODELLING AND CASTING; WITH Miscellaneous Receipts^ necessary for the better attainment of these eeegant ARTS. LONDON : PRINTED BY AND FOR WILLIAM COLE, No. 10, NEWGATE-STREET. Pricff One Shillings it'l 6.2- 6 22 a?3i