COʻLOR, v. a., v. n., & n. s. 196 COLORS. Lat. coloro, pays but single duty, when he ought to pay double. color. The substantive has applications which distinguish it from the verb, and these we must mark. The appearance of bodies to the eye only; hue; dye. The freshness or appearance of blood in the face. In the plural, a standard; an ensign of war. Colours ne know I non, withouten drede, Chaucer's Canterbury Tales. Her hair shall be of what colour it please God. Shakspeare. He at Venice gave Id. Richard II. Id. Merry Wives of Windsor. When on the east the morning ray, Hangs out the colours of the day, The bee through these known allies hums, Beating the dian with its drums. Marve.. All in a moment through the gloom were seen Each gaudy bird some slender tribute brings, Gay's Rural Sports. It is a vulgar idea of the colours of solid bodies, when we perceive them to be a red, or blue, or green tincture of the surface; but a philosophical idea, when we consider the various colours to be different sensations, excited in us by the refracted rays of light, reflected on our eyes in a different manner, according to the different size, or shaps, or situation of the particles of which surfaces are composed. Watts. The verb signifies to mark with some hue or dye; to palliate; to excuse; to dress in specious colors, or fair appearances belied by the reality; to make plausible. In the neuter sense to blush. These applications are common to the substantive, and to all the other branches of the word; technically, to color strangers' goods, is when a freeman allows a foreigner to enter goods at the custom-house in his name, so that the foreigner They have now a colourable pretence to withstand innovations, having accepted of other laws and rules already. Spenser. Had I sacrificed ecclesiastical government and revenues to their covetousness and ambition, they would have found no colourable necessity of an army. King Charles. He colours the falsehood of Eneas by an express command from Jupiter to forsake the queen. Dryden's Dedicat. Æneid. Titian, Paul Veronese, Van Dyck, and the rest of the good colourists, have come nearest to nature. Dryden's Dufresnoy. The rays, to speak properly, are not coloured: in them there is nothing else than a certain power and disposition to stir up a sensation of this or that colour. Newton's Optics. Transparent substances, as glass, water, and air, when made very thin by being blown into bubbles, or otherwise formed into plates, exhibit various colours, according to their various thinness; although at a greater thickness they appear very clear and colour less Id. Pellucid colourless glass or water, by being beaten into a powder or froth, do acquire a very intense whiteness. Bentley. ture. skies. Pope. We have scarce heard of an insurrection that was not coloured with grievances of the highest kind, or countenanced by one or more branches of the legisla Addisons's Freeholder. But as the slightest sketch, if justly traced, Is by ill 'colouring but the more disgraced; So by false learning is good sense defaced. Flowers fresh in hue, and many in their class, Implore the pausing step, and with their dyes Dance in the soft breeze in a fairy mass; The sweetness of the violet's deep blue eyes, Kissed by the breath of heaven, seems coloured by its Byron's Childe Harold. COLORS, in the Latin and Greek churches, are used to distinguish several mysteries and feasts celebrated therein. Five colors only are regularly admitted, viz. white, green, red, violet, and black. The white is for the mysteries of our Saviour, the feast of the Virgin, those of the angels, saints and confessors; the red is for the solemnities of the holy sacrament, the feasts of the apostles and martyrs; the green for the time between pentecost and advent, and from epiphany to septuagesima; the violet in advent and Christmas, in vigils, rogations, &c. and in votive Gules, fig. 1, is expressed by lines perpendicular from top to bottom. Azure, fig. 2, by horizontal lines from side to side. Sable, fig. 3, by horizontal and perpendicular lines crossing each other. Vert, fig. 4, by hatched lines from right to left diagonally. Purpure, fig. 5, by hatched lines from the sinister chief to the dexter base, diagonally; and Tenne, tawny, fig. 6, by diagonal lines from the dexter to the sinister side of the shield, traversed by perpendicular lines. it their interest to conceal their methods, it hap pens that there is not only no distinct theory of this art, but few good receipts to be obtained for making any color. SECT. I.-GENERAL DIVISIONS OF COLORS. 1. The first general division of colors is into opaque and transparent. The former comprehends such colors as, when laid over paper, wood, &c. cover them fully, so as to efface any other painting or stain that might have been there before. The latter includes colors of such a nature as to leave the ground on which they are laid visible through them. Of the first kind are white lead, red lead, vermilion, &c., of the second are the colors used for illuminating maps, &c. 2. A second division is into oil colors and water colors; or such as are appropriated to painting in oil and water. Most of those which are proper for painting in water, are also proper for being used in oil. There is, however, this remarkable difference betwixt colors when mixed with water and with oil, that such as are quite opaque in water will become perfectly transparent in oil. Thus, blue verditer, though exceedingly opaque in water, if ground with oil, seems totally to dissolve, and will become very transparent. The same thing happens to such colors as have for their basis the calx of tin, alabaster, or calcareous earth. The most perfectly opaque colors in oil are such as have lead, mercury, or iron, for their basis: to the latter, however, Prussian blue is an exception; for, though the Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. basis of that color is iron, it proves quite trans 00000 COLORS, in the military art, are large silk flags fixed on half pikes, and carried by the ensign; whence the purchase of an ensigncy is called the purchase of a pair of colors. The size of the colors, in England, should be six feet six inches flying, and six feet deep on the pike, and the length of the pike nine feet ten inches. The cords and tassels of the whole are crimson and gold mixed. COLORS, CAMP, a small sort of colors placed on the right and left of the parade of the regiment when in the field: they are eighteen inches square, and of the color of the facing of the regiment, with the number of the regiment upon them. COLOR-MAKING is the act of preparing the diferent kinds of colors used in painting, drawing, dyeing, calico-printing, &c. The art of dyeing is sufficiently important to claim our distinct notice; the colors of calico-printing follow; our remarks and directions in this paper are more particularly directed to the preparing of colors used in drawing and painting. This art is altogether, as we have seen, a branch of chemistry; and one of the most curious, though least understood, parts of it. The principles on which color-making depends differ greatly, however, from those en which the theory of other parts of chemistry is founded; and the practical part being in the hands of those who often find parent when ground with oil. In water colors, those prepared from metals, Prussian blue alone excepted, are always opaque; from vegetables or animals, transparent. Charcoals, however, whether vegetable or animal, are opaque both in water and oil. 3. Colors are farther divided into simple and compound. The simple are such as require nothing to be superadded, to make a full strong color, without regarding whether they are formed of many or few ingredients. In this view, white lead, red lead, vermilion, calces of iron, &c. are simple colors. The compounds are formed by the union of two or more coloring substances: as blue and yellow united together to form an orange, a white earth or calx mixed with the red color of cochineal or Brasil to form a lake, &c., and thus carmine, lake, rose pink, Dutch pink, English pink, &c. are compound colors. 4. The last and most important division of colors is into true and false. By true colors are meant those which retain their color under every possible variety of circumstances, without fading in the least the false are such as do not; but either lose their color altogether, or change to some other. SECT. II.-OF THE CAUSES OF THE FADING OF COLORS. Colors are chiefly affected by their being exposed to the sun in summer, and to the cold air in winter; but to this there is one exception, viz. white lead; which, when ground with oil, retains its whiteness if exposed to the weather, but degenerates into a brownish or yellow color if kept close. In water this substance is very apt to lose its color, whether exposed to the air or not. The great desideratum in color-making is to produce such colors as will not fade by exposure to the weather; and, indeed, it is to be regretted, that the most beautiful are in general the least permanent. It may for the most part, however, be expected, that the more simple any color is, the less liable it will be to change upon exposure to the air. The principal difficulty of ascertaining whether a color will fade or not, arises from our ignorance concerning the nature of coloring substances. We may hold it as a rule, however, that whatever change of color is produced in any substance by exposure to the sun and air, that color to which it changes will bid fair for being permanent, and therefore ought to be employed where it can be done. Of such changes the instances are rare. One is in the purple of the ancients, which assumed its color by exposure to the sun, and consequently was exceedingly permanent. Another is in the solution of silver; which, being mixed with chalk, the precipitate turns to a purplish black where it is exposed to the sun. A third is in solutions of indigo by alkaline substances, which constantly appear green till exposed to the air by spreading them very thin, upon which they become almost instantaneously blue, and continue so ever after. Sometimes, though still more rarely, a very remarkable change of color happens, upon mixing two vegetable juices together. Almost the only instance of this we have on the authority of Mr. Foster, who says that the inhabitants of Otaheite dye their cloth of a crimson color, by mixing together the yellow juice of a small species of fig with the greenish juice of a fern. But the most remarkable alterations of color are effected by different metallic and saline solutions, mixed with certain animal and vegetable substances; and with these the color-maker will be principally conversant. It is a fact well known in chemistry, that acids mixed with blue vegetable juices turn them red, and alkalis green. It is equally certain, though not so generally known, that acids of all kinds generally tend to heighten red colors, so as to make them approach to the scarlet or true crimson; and alkalis to darken, or make them approach to blue or purple. Mixed with yellow colors, acids also universally tend to brighten the yellow; and alkalis to turn it to an orange, and make it become more dull. But, though this is very generally the case, all acids are not equally powerful in this respect. The nitrous acid is found to heighten the most of any, and the marine acid the least of the mineral ones. The vegetable acids are less powerful than the mineral. Thus, if with a tincture of cochineal in water or spirit of wine, is mixed pure nitrous acid, it will change the color to an orange or flame color, which it will impart to cloth. If the vitriolic acid is used, a full scarlet, inclining to crimson rather than orange, is produced. With marine acid a true crimson color, bordering on purple, is the consequence. Alkalis, both fixed and volatile, change the color to a purple which is brighter with the volatile than the fixed alkalis. It is obvious that, whatever colors are produced by the mixtures of different substances together, the permanency of these colors can only be in proportion to the ability of such mixtures to resist the weather. Thus, suppose a high scarlet or orange color is produced by means of spirit of nitre, it is plain that, was such a color exposed to the air, it could remain no longer than the spirit of nitre which produced it remained. In proportion, therefore, as the spirit of nitre was exhaled, or otherwise destroyed, it behoved the color to fade, and at last to be totally destroyed: and thus, in proportion to the destructibility of the substances by which colors are produced, will be the disposition of such colors to fade, or the contrary. Alkalis are in this respect much more destructible than acids, and consequently less proper for the preparation of colors. Of the acids, the nitrous seems most destructible, the vitriolic less so, and the marine least of all. From the extreme fixity of the phosphorine acid and sedative salt, perhaps they might be of service in preserving colors. SECT. III.-OF THE FORMATION OF OPAQUE COLORS. As all colors, whether derived from the animal or vegetable kingdom, must be extracted either by pure water or some other liquid menstruum, they cannot be used for the purposes of painting till the coloring substance is united with some earthy or solid matter, capable of giving it a body, as the workmen call it; and, according to the nature of this substance, the color will be transparent or otherwise. This basis ought to be of the most fixed and durable nature; unalterable by the weather, by acids, or by alkalis. It ought also to be of a pure white color, and easily reducible into an impalpable powder. For this reason all earthy substances should be avoided as being acted upon by acids; and, therefore, if any of these were added to heighten the color, they would be destroyed, and their effect totally lost. Precipitates of lead, bismuth, &c., though exccedingly fine and white, ought also to be avoided, as being apt to turn black by exposure. Alumina, in many instances, answers very well: but the substance to be chiefly preferred to all others, is calx of tin, prepared either by fire or the nitrous acid. This is so exceedingly refractory as not only to be unalterable by alkalis, acids, or the sun and weather, but even by the focus of a very large burning mirror. It is besides white as snow, and capable of being reduced to an extreme degree of fineness, insomuch that it is made use of for polishing metalline speculums. For these reasons, it is the most proper basis for all fine colors. For coarse ones, the white precipitate of lead will answer very well. It has a very strong body, i. e. it is very opaque, and will cover well; may be easily ground fine, and is much less apt to turn black than white lead; it is besides very cheap, and may be prepared at the small expense of 3d. per per pound. The general method of extracting colors from any vegetable or animal substance, and fixing them on a proper basis, may thus be very easily understood. For this purpose, a quantity of calx of tin is to be procured, in proportion to the quantity of color desired. This must be well rubbed in a glass mortar, with a little of the substance designed for brightening the color, as alum, cream of tartar, spirit of nitre, &c. after which it must be dried, and left for some time, that the union between the two substances may be as perfect as possible. If the color is to be a very fine one, suppose from cochineal, the coloring matter must be extracted with spirit of wine without heat. When the spirit is sufficiently impregnated, it must be poured by little and little upon the calx, rubbing it constantly, to distribute the color equally through all parts of the calx. The spirit soon operates, and leaves the calx colored with the cochineal. More of the tincture is then to be poured on, rubbing the mixture constantly as before; and thus, with proper management, may very beautiful colors, not inferior to the best carmine, be prepared at a moderate expense. In like manner by substituting, for the cochineal, Brasil wood, turmeric, logwood, &c. different kinds of red, yellow, and purple, will be produced. For the coarser colors aqueous decoctions are to be used in a similar manner; only as these are much longer evaporating than the spirit of wine very little must be poured on at a time, and the colors ought to be made in large quantity, on account of the tediousness of the process. We have hitherto mentioned only the effects of the pure and simple salts, viz. acids and alkalis, on different colors; but by combining the acids with alkalis, earths, or metals, these effects may be varied almost ad infinitum; nor is there any rule yet laid down by which we can judge a priori of the changes of color that will happen on the admixture of this or that particular salt with any coloring substance. In general, the perfect neutral salts act weakly; the imperfect, especially those formed from metals, much more powerfully. Alum and sal ammoniac considerably heighten the color of cochineal, Brasil, turmeric, fustic, madder, logwood, &c. The same thing is done, though in a less degree, by common salt, Glauber's salt, saltpetre, and many other neutrals. Solutions of iron in all the acids strike a black with each of the above-mentioned substance; and likewise with sumach, galls, and other astringents. Solutions of lead universally debase red colors to a dull purple. Solutions of copper change the purple color of logwood to a pretty good blue; and, in general, solutions of this metal are friendly to blue colors. The effects of solutions of gold, silver, and mercury, are not so well known; they seem to produce dark colors of no great beauty. The most powerful solution, however, with regard to a great number of colors, is that of tin, made in aqua regia. Hence we may see the fallacy of Mr. Delaval's hypothesis concerning colors, that the least refrangible ones are produced by the most dense metals for tin which has the least density of any metal, has yet, in a state of solution, the most extraordinary effects upon the least refrangible colors as well as those that are most so. The color of cochineal is changed by it into the most beautiful scarlet; a similar change is made Brasil upon the coloring matter of gum-lac. wood is made to yield a fine purple crimson; logwood, a beautiful dark purple; turmeric, fustic, weld, and all yellow-coloring woods and flowers, are made to communicate colors far more beautiful than can be got from them by any other method. The blue colors of the flowers of violet, eye-bright, iris, &c. are heightened so as to equal, if not excel, the blue produced by a solution of copper in copper in volatile alkali. In short this solution seems to be of much more extensive use in color-making, when properly applied, than anything hitherto thought of. It is not, however, universally serviceable. The color of madder it totally destroys, and likewise that of saf-flower, changing them both to a dull orange. It likewise spoils the color of archil; and, what is very remarkable, the fine red color of tincture of roses made with oil of vitriol is changed by it to a dirty green. SECT. IV.-OF THE CHOICE OF COLORING MA TERIALS. One of the most important considerations in color-making is to choose such materials as produce the most durable colors. If these can be procured, an ordinary color from them is to be preferred to a bright one from those which fade sooner. In what the difference consists between the colors that fade and those which do not, is not known with any degree of certainty. From some appearances it would seem, that those substances which are most remarkable for keeping their color, contain a viscous glutinous matter, so combined with a resinous one as to be soluble in water and spirit of wine. The most durable red color is prepared from gum-lac. This is very strongly resinous, though, at the same time, so far glutinous, that the coloring matter can be extracted from it by water. Next to gum-lac are madder roots and cochineal. The madder is an exceedingly penetrating substance, insomuch that, when given to animals along with their food, it tinges their bones of a deep red color. Its coloring matter is soluble both in water and spirit of wine. Along with the pure red, however, there is in madder a kind of viscous astringent substance, of a dark brown color, which seems to give the durability to the whole. The coloring matter of cochineal, though soluble both in water and spirit of wine, is very tenacious and mucilaginous, in which it bears some resemblance to the purpura of the ancients, which kept its color exceedingly well. Where the colors are fugitive, the tinging rubstance seems to be too resinous or too mucilaginous. Thus the colors of Brasil, turmeric, &c. are very resinous, especially the latter; insomuch that the coloring matter of turmeric can scarcely be extracted by water. Both these are perishable, though beautiful colors; and much more the red, purple, and blue flowers, commonly to be met with. These seem to be entirely mucilaginous without the least quantity of resinous matter. The yellow flowers are different, and in general keep their color pretty well. Perhaps fugitive colors might be rendered durable, by adding a proportion of gum or resin. A process has been given by Mr. Hellot for imparting durability to the color of Brasil. It consists only in letting SECT. V. OF THE PIGMENTS COMMONLY SOLD The preceding sections contain the substance of all that can as yet be depended upon for establishing a general theory of color-making. We now proceed to give an account of the different pigments generally to be found in the color shops. 1. BLACK.-These are the lamp-black, ivoryblack, blue-black, and Indian-black. The first is the finest of what are called the soot-blacks, and is more used than any other. Its preparation is described in the Swedish Transactions for 1754, as a process dependent on the making of common resin: the impure resinous juice, collected from incisions made in pine and fir-trees, is boiled down with a little water, and strained whilst hot through a bag: the dregs and pieces of bark left in the strainer are burnt in a low oven, from which the smoke is conveyed through a long passage into a square chamber, having an opening on the top on which is a large sack made of thin woollen stuff: the soot or lamp-black, concretes partly in the chamber, from whence it is swept out once in two or three days, and partly in the sack, which is now and then gently struck upon, both for shaking down the soot, and for clearing the interstices betwixt the threads, so as to procure a sufficient draught of air through it. In this manner lamp-black is prepared at the turpentine houses in England, from the dregs and refuse of the resinous matters which are there manufactured. Dr. Lewis has some curious observations on this subject. The soot, says he, arising in common chimneys, from the more oily or resinous woods, as fir and pine, is observed to contain more dissoluble matter than that from the other woods; and this dissoluble matter appears, in the former, to be more of an oily or resinous nature than the latter; spirit of wine extracting it most powerfully from the one, and water from the other. The oiliness and solubility of the soot seeming therefore to depend on those of the subject it is made from, it has been thought that lamp-black must possess these qualities in a greater degree than any kind of common soot. Nevertheless, on examining several parcels of lamp-black, procured from different shops, I could not find that it gave any tincture at all, either to spirit or to water. Suspecting some mistake or sophistication, or that the lampblack had been burnt or charred, as it is to fit it for some particular uses, I prepared myself some soot from linseed oil, by hanging a large copper pan over the flame of a lamp to receive its smoke. In this manner the more curious artists prepare lamp-black for the nicer purposes; and from this collection of it from the flame of a lamp, the pigment probably received its name. The soot so prepared gave no tincture either to water or spirits, any more than the common lamp-black of the shops. I tried different kinds of oily and resinous bodies with the same event; even the soots obtained from fish oils and tallow did not appear to differ from those of the vegetable oils and resins. They were all of a finer color than the lamp-black commonly sold. Soot was also collected in like manner from fir, and other woods, by burning small pieces of them slowly under a copper pan. All the soots were of a deeper black color than those obtained from the same kinds of woods in a common chimney; and very little, if at all, inferior to those of the oils: they gave only a just discernible tincture to water and spirit, while the soots of the chimney imparted a strong deep one to both. The soot of mineral bitumens, in this close way of burning, appears to be of the same qualities with those of woods, oils, and resins: in some parts of Germany, great quantities of good lamp-black are prepared from a kind of pit-coal. It appears, therefore, that the differences of soots do not depend altogether on the qualities of the subjects, but in a great measure on the manner in which the subject is burnt, or the soot caught. The soots produced in common chimneys, from different kinds of wood, resinous and not resinous, dry and green, do not differ near so much from one another, as those which are produced from one kind of wood in a common chimney, and in the confined way of burning above-mentioned. Ivory black is prepared from ivory or bones burnt in a close vessel. This, when finely ground, forms a more beautiful and deeper color than lamp-black; but, in the common methods of manufacturing, it is so much adulterated with charcoal dust, and so grossly levigated, as to be unfit for use. An opaque deep black, for water color, is made by grinding ivory black with gumwater, or with the liquor which settles from the whites of eggs after they have been suffered to stand a little. Some use gum-water and the whites of eggs together, and say, that a small addition of the latter makes the mixture flow more freely from the pencil, and improves its glossiness. It may be observed, however, that though ivory-black makes the deepest color in water as well as in oil painting, yet it is not on this account always to be preferred to other black pigments. A deep jet black color is seldom wanted in painting; and in the lighter shades, whether obtained by diluting the black with white bodies, or by applying it thin on a white ground, the particular beauty of the ivory-black is in a great measure lost. Blue black is said to be prepared from the burnt stalks and tendrils of the vine. These, however, the color-makers seldom give themselves the trouble of procuring, but substitute in its place a mixture of ivory-black and common blue used for clothes. Indian ink is an excellent black for watercolors. It has been discovered by Dr. Lewis to consist of a mixture of lamp-black and commen glue. Ivory-black, or charcoal, he found to answer equally well, provided they were levigated to a sufficient degree of fineness, which indeed requires no small trouble. |