Linen is dyed of the shades of olive and drake's neck green, by first giving it a blue ground, then galling and dipping it in a bath of acetate of iron; afterwards passing it through a bath of weld, combined with verdigris; and through another containing sulphate of copper, finally brightening the color by immersion in a solution of soap.

246. The green, says M. Berthollet, obtained by giving a yellow color to a stuff which has been previously dyed blue, and afterwards washed, presents nothing obscure. The color inclines more or less to yellow, or to blue, according to the tint of blue given, and the strength of the yellow bath. The intensity of the yellow is increased by alkalis, by sulphate of lime, by ammoniacal salts. It is diminished by acids, alum, and solution of tin. The shades vary likewise from the nature of the yellow substance employed.

These different effects will be obtained with the same ingredients in the formation of the Saxon green, according to the process adopted. If the Saxon blue be first dyed, and the yellow color be next given separately, the effects will be analogous to those just mentioned. But if solution of indigo be mixed with the yellow ingredients, the results are not the same, because the sulphuric acid acts in this case on the coloring particles, impairing the intensity of the yellow. If a succession of shades be dyed in a bath composed of yellow and the solution of indigo, the last approach more and more to yellow, because the particles of indigo become attached to the stuff in preference to the yellow ones, which therefore become predominant in the bath.

OF DYEING VIOLET COLOR, &c. 247. Of Dyeing Wool Violet, &c.-From the mixture of red and blue are obtained violet, purple (columbine), dove-color, pansy, amaranth, lilac, mallow, and a great many other shades, determined by the nature of the substances, whose red color is combined with a blue color, of which one becomes more or less predominant over the other, according to the proportions of the ingredients, and the other circumstances of the process. Hellot observes, that stuff which has been dyed scarlet, takes an unequal color when blue is to be united with it. The blue is therefore given first, which, even for violet and purple, ought not to be deeper than the shade distinguished by the name of sky-blue; a boiling is given with alum mixed with two-fifths of tartar; the stuff is then dipped in a bath composed of nearly two-thirds as much cochineal as for scarlet, to which tartar is always added.

248. The circumstance which distinguishes the process for purple from that for violet, is that for the former a lighter blue ground is given, and a larger proportion of cochineal is employed. These colors are frequently dyed after the reddening for scarlet, such quantities of cochineal and tartar being added as are necessary; the operation is managed in the same way as for scarlet. But lilacs, pigeon's necks, &c., are commonly dipped in the boiling, which has served for violet, after alum and tartar have been added to it: the blue ground having been proportioned

to the shade required, the quantity of cochineal is also adjusted in a similar manner; a little solution of tin is added for some reddish shades, snch as peach blossom. It is to be observed, that, though the quantity of cochineal is diminished according to the lightness of the shade required, the quantity of tartar is not lessened, so that the proportion of it, compared with that of the cochineal, is so much the greater, as the color required is lighter.

249. M. Poerner is of opinion, that, to procure the colors composed of red and blue, it is advantageous to employ the solution of indigo in sulphuric acid, because a great variety of shades is thus more easily obtained, and the process is not so long or expensive. But the colors thereby obtained are less durable than when the blue vat is employed. He says, however, that they have sufficient permanence, if a solution of indigo be used to which some alkali has been added.

The effects may be easily varied, by giving a preparation to the stuff with different proportions of alum and tartar, or with solution of tin; and by dyeing with different proportions of cochineal and solution of indigo.

250. A process for dyeing wool of a purple color is given by M. Berthollet, as having been communicated to him by Descroizilles. It is this:-If it be wool in the fleece which is to be dyed, one-third of its weight of mordaut is required; if it be a woven stuff, only a fifth is necessary. A bath is prepared at a temperature which the hand can bear; the mordant is well mixed with it; and the wool or stuff is then immersed. It is to be properly agitated, and the same degree of heat is to be kept up for two hours, which may be even increased a little towards the end. It is then lifted out, aired, and very well washed. A new bath of pure water at the same heat is prepared; a sufficient quantity of violet wood is added to it; the stuff is then let down, and agitated; and the heat is urged to the boiling point, at which it is maintained for a quarter of an hour. The stuff is then lifted out, aired, and carefully rinsed. The dye is now completed. If a decoction of one pound of logwood has been used for three pounds of wool, and proportionately for the stuffs which require a smaller dose, a beautiful violet is obtained, to which a sufficient quantity of Brasil-wood gives the shade known by the name of prune de monsieur.

251. The ingenious author from whom we quote the above, thus endeavours to explain the process :-

If we may venture an opinion, without having made direct experiments on a complicated process, such as that communicated by Descroizilles, and which is still employed advantageously in some manufactories with modifications which we do not know, we would suggest the following explanation.

The muriate of soda is decomposed by the sulphuric acid, and the muriatic acid set at liberty dissolves the tin.

A portion of the tin is precipitated by the tartaric acid, whence the deposite is occasioned. But a portion which remains in solution serves to modify the effect, as we have seen with regard

to cochineal. The oxide of copper, present in this preparation, forms blue with the coloring particles of the indigo; the oxide of tin with the same wood gives violet, and red with the coloring matter of Brasil-wood.

252. Of Dyeing Silk Violet, &c.-There are two kinds of violet colors given to silk, these are, by the French writers on dyeing, distinguished into the fine and the false. The fine violet may be given by dyeing the silk with cochineal, and afterwards passing it through the indigo vat. The preparation and dyeing of the silk with cochineal are the same as for crimson, with the omission of tartar and solution of tin, by means of which the color is heightened. The quantity of cochineal made use of is always proportioned to the required shade; but the usual proportion for a fine violet color is two ounces of cochineal for every pound of silk. When the silk is dyed, it is washed at the river, twice beetled, dipped in a vat of a strength proportioned to the depth of the violet shade, and then washed and dried with precautions similar to those which all colors require that are dyed in a vat. If the violet is to have greater strength and beauty, it is usual to pass it through the archil bath, a practice which, though frequently abused, is not to be dispensed with for light shades, which would otherwise be

too dull.

253. When silk has been dyed with cochineal, as above directed, a very light shade of blue must be given it for purple. Only the deepest shades are passed through a weak vat. For those which are less so, cold water is had recourse to, into which a little of the blue vat is put, because they would take too much blue in the vat itself, however weak it may be. The light shades of this color, such as pink, gridelin, and peach-blossom, are made in the same manner, with a diminution of the proportion of cochineal.

254. The spurious violets are given to silk in various ways. The most beautiful, and those most in use, are prepared with archil. The strength of the archil bath is proportioned to the color wished for: the silk, to which a beetling in the river has been given on its coming out of the soap, is turned through it round the skein sticks. When the color is thought to be deep enough, a trial is made on a pattern in the vat, to see if it takes the violet that is wanted. If it is found to be at the proper pitch, a beetling is given to the silk at the river, and it is passed through the vat as for fine violets. Less blue, or less archil, is given, according as the violet is wished to incline to red or to blue.

255. A violet color may be imparted to silks by immersing them in water impregnated with verdigris, as a substitute for aluming, and then giving them a bath of logwood, in which they assume a blue color; which is converted into a violet, either by dipping them in a weaker or stronger solution of alum, or by adding it to the bath; the alum imparts a red shade to the coloring matter of the logwood. This violet possesses but little beauty, or permanence, but if the alumed silk be immersed in a bath of Brasilwood, and next in a bath of archil after washing it at the river, a color is obtained possessing a much higher degree of beauty and intensity.

M. Decroizilles' process, above related, for dyeing wool, was found to succeed equally well, according to his account, in communicating a violet color to silk.

256. Of Dyeing Cotton and Linen Violet, &c.— The process in most common use for dyeing cotton and linen of the violet colors is the following:The stuffs have first a blue ground communicated to them in the indigo vats according to the shade required; they are then dried. After this they must be galled in the proportion of three ounces of galls to a pound: they are left for twelve or fifteen hours in the gall bath, after which, they are wrung and dried again. They are then passed through a decoction of logwood, and when well soaked are taken out, and two drachms of alum,and one of dissolved verdigris, for each pound of stuff are added to the bath; the skeins are then redipped on the sticks, and turned for a full quarter of an hour, when they are taken out to be aired; after which they are again completely immersed in the bath for a quarter of an hour, then taken out and wrung. The vat which has been employed is then emptied; half of the decoction of logwood which had been reserved is poured in; two drachms of alum are added, and the stuff dipped afresh, until it is brought to the shade required. The decoction of logwood ought to be stronger or weaker according to the shade required; this violet stands the action of the air tolerably well, but is not so durable as that obtained by madder.

257. Permanent purple and violet colors may be given to cotton stuffs that have been dyed a Turkey-red, by adding to the alum steep a proportion of sulphate of iron suited to the shade required. Cotton also that has been dyed a light blue with indigo, may be changed to purple or violet by passing the stuff through a bath prepared with the aluminous mordant, and dyeing with madder.

OF DYEING ORANGE.

258. Of Dyeing Wool Orange.-Orange colors are produced by the mixture of red and yellow; and, by varying the proportions of the ingredients, an almost endless variety of shades may be obtained.

Poerner describes a great many varieties which he obtained by employing weld, saw-wort, dyers' broom, and some other yellow substances; as also by introducing into the preparation of the cloth, or into the bath, tartar, alum, sulphate of zinc, or sulphate of copper.

Different colors may in like manner be procured from the madder, which is associated with yellow substances. It is thus that the mordores and the cinnamons are dyed; colors commonly formed in two baths. The maddering is first given, preceded by a bath of alum and tartar as for ordinary maddering; and then a bath of weld is employed.

For cinnamon a weaker maddering is given, and commonly a bath is used which had served for the mordore. The proportions are varied according as the red or the yellow is wished to predominate. Sometimes nut-galls are added, and sometimes the color is deepened by a browning.

Occasionally the sole object is to give a reddish tone to the yellow; the stuff just dyed yellow may, in this case, be passed through a bath of madder, more or less charged according to the intention.

Brasil-wood is likewise employed along with the yellow substances, and sometimes it is associated with cochineal and madder.

When, instead of weld or other yellow substances, root of walnut, walnut-peels, or sumach, are used, tobacco, snuff, chestnut, musk colors &c., are produced.

259. Of Dyeing Silk Orange.-Morrones, cinnamons, and all the intermediate shades are given to silk, by logwood, Brasil, and fustic a bath is prepared by mixing decoctions of these three woods made separately; the proportion of each is varied according to the shade required, but that of fustic ought to prevail; the bath should be of a moderate temperature; and the silk, after being scoured and alumed in the usual manner, is immersed in it. The silk is turned on the skein sticks in the bath, and when taken out, if the color be uniform, it is wrung and dipped in a second bath of the three ingredients, the proportions of which are regulated according to the effect of the first bath, in order to obtain the shade required.

For some colors blue is united to red and yellow, it is thus olives are produced: a blue ground is first given, then the yellow dye, and lastly, a slight maddering. Olive may be dyed without using the blue vat, by dipping the silk in a very strong weld bath, after being first alumed; to this a decoction of logwood is afterwards added, and, when the silk is dipped, a little solution of alkali is put in, which turns it green, and gives the silk the olive color. The silk is repeatedly dipped in this bath until it has acquired the proper shade.

260. For the color termed russet olive, or rotten olive, fustet and logwood, without alkali, are added to the bath after the welding. If a more reddish color be wished for, only logwood is added. A kind of reddish olive is also made by dyeing the silk in a bath of fustet, to which more or less sulphate of iron and logwood are added.

ACIDS, their action on colors, 15. ALKALIS, their action on colors, ib. ALUM, its use as a mordant, 20. ALUMINA, acetite of, ib.

261. Of Dyeing Cotton and Linen Orange.The usual combinations of scarlet and orange, are produced with difficulty. On this head Dr. Bancroft remarks, that, as cochineal and the tin mordant cannot be advantageously employed to dye linen or cotton, it is necessary for these substances solely to rely on the aluminous mordant, and to select the red coloring matter from other dye stuffs, especially from madder, with which the yellow of weld, quercitron bark, or fustic may be combined in such proportions as may be sufficient for the required color. M. Berthollet gives some processes for colors, which he regards as mixtures of red and yellow, though some of them may more properly be considered browns or greens. The various shades of morrone are given to cotton, by first galling, and then dipping it in a bath of acetate of iron, formed by the pyroligneous acid, and afterwards in a bath of weld and verdigris, after which it is dyed with fustic, sometimes with the addition of soda and alum. It is then completely washed, passed through a strong madder bath; then dipped in a weak solution of sulphate of copper; and, lastly, passed through a bath containing soap.

262. The shades cinnamon and mordore are thus given: the stuffs are first dyed with verdigris and weld, then dipped in a solution of sulphate or acetate of iron, out of which they are wrung and dried. After this they are galled, allowing three ounces of galls to each pound of stuff, again dryed, alumed, and passed through a madder bath. They are then washed and immersed in a warm soap lie, through which they are turned till the color is sufficiently bright.

263. The shades of color usually denominated gray, have already been treated of, and the processes for dyeing them need not here be repeated.

264. Several highly respectable writers who have done great justice to the subject of dyeing have connected with their treatises on it a brief view of the process of calico printing: we should have followed their example in the present instance, nad we not considered the subject, in its present highly improved state, as meriting a distinct notice, which will be found in another part of our work. See PRINTING, CALICO.

FLAX, method of treating it for dyeing, 101.
FRENCH CHEMISTS, dyeing indebted to them, 1.
FUSTET, or Venus's sumach, 201.

FISTIC superseded by quercitron bark, 239.

GALL-NUT, account of, 53. Different kinds of, ib.
Use of, in dyeing black, 121. In making ink, 60.
GRAY, how dyed, 138.

GRREKS, their ignorance of dyeing, 5.

GREEN, of dyeing wool, 236. Silk, 240. Linen and
cotton, 243. English, how to dye, 242.

HAUSSMANN, his method of preserving vats, 165.
HELLOT, his treatise on dyeing, 10.
HENRY, Dr., on mordants, 18.

INDIA, parent of the arts and sciences, 6. State of
lyeing in, 7.

INDIGO VAT, 152.

PURPLE COLOR, the origin of, 4. Whence

tracted, ib.

PYROLIGNEOUS ACID, 137.

PYROLIGNITE OF IRON, of dyeing cotton with, ib.

QUERCITRON BARK produces a fine yellow, 192. Ex-
periments on, by Bancroft, 191-196.

RED, how to dye, on wool, 169. On silk, 173. On
totton, 178. Adrianople or Turkey, 180. How
dyed at Rouen, 182.

ROSE COLOR, a lively, 177. ·

SANDERS, or sandal wood, 229. Coloring matter
of, how extracted, ib.

SAW-WORT, its use in dyeing orange shades, 258.
SAXON BLUE, how dyed, 166. Green, how dyed, 239.
SCARLET, how dyed, 184. Improved method, by
Bancroft, 191. Effect of candle light on, 196.
SHELL-FISH producing purple color, 4.

SILK, how freed from its gum, 92-97. How dyed
black, 126. Blue, 154. Green, 240. Purple,
253. Yellow, 214.

SPIRIT, dyers', 193. Superior and cheaper kind, ib.
SUMACH, Berthollet's experiments on, 228.

TANNIN, what, 66.

TARTAR, an earthy mordant, 22. Its action on alum,
23.

TIN, oxide of, used as a mordant, 27.
TURKEY-RED, method of dyeing, 180.

KERMES used in dyeing red, 168.

LAC used in dyeing, 168.

LAVOISIER, his experiments on galls, 62.

URE, Dr., his analytical experiments on the four
principal subjects of dyeing, 84.

URINE, a solvent of indigo, 153.

VAT, indigo, 152.

133.

144. Liable to accidents, 147. Repelled, what,
ib. Two described by Hellot, 153. Method of re-
covering repelled, 148. Method of constructing at
Rouen, 160.

VELVET, method of dyeing at Genoa, 132.
VENUS'S SUMACH, or fustet, 201.

VERDIGRIS used in dyeing black, 121. In dyeing
green, 245.

VIOLET COLOR, how dyed on wool, 247. On silk,
252. On cotton, 256.

WALNUT-PEELS, their use in dyeing, 227.

OIL, its use in dyeing cottons black, 137.

OLIVE COLOR, how dyed, 259, 260.

paring, 116. Hard, how to soften, 117.
WELD, its use in dyeing yellow, 203.
WOAD used in dyeing blue, 144.

Rome are perhaps of this kind; and the various landscapes in The Fleece have been particularly admired. On his return to England he published The Ruins of Rome, 1740. As his turn of mind was rather serious, he was advised to enter into holy orders; and he found no difficulty in obtaining them. He was ordained by the bishop of Lincoln. About the same time he married a lady of Coleshill named Ensor, whose grandmother was a Shakspeare, descended from a brother of the great Shakspeare. His ecclesiastical provision was, for a long time, but slender. His first patron, Mr. Harper, gave him, in 1741, Calthorp in Leicestershire, of £80 a year, on which he lived ten years; and in April 1751 exchanged it for Belchford in Lincolnshire, of £95 which was given him by lord chancellor Hardwicke. His condition now began to mend. In 1752 Sir John Heathcote gave him Coningsby, of £140 a year; and in 1756, when he was LL.B. without any solicitation of his own, obtained for him from the chancellor, Kirkby on Bane, of £110. In 1757 he published the Fleece, his greatest poetical work; but a consumptive disorder, with which he had long struggled, carried him off in 1758. Mr. Dyer's character, as a writer, has been fixed by three poems, Grongar Hill, The Ruins of Rome, and The Fleece; wherein a poetical imagination, perfectly original, a natural simplicity connected with and often productive of the true sublime, and the warmest sentiments of benevolence and virtue, have been universally observed and admired. These pieces were published separately in his lifetime; but, after his death, they were collected and published. in one volume 8vo. in 1761, with a short account of him prefixed.

DYER (Sir James), an eminent English lawyer, chief judge of the court of common pleas in the reign of queen Elizabeth. He died in 1581, and, about twenty years after, was published his large collection of Reports, which have been highly esteemed for their succinctness and solidity. He also left other writings behind him relative to his profession.

DYNAMICS, from ovvaus, power, that branch of mechanics which has for its object the action of forces on solid bodies, when the result of that action is motion; and in which, since all motion occupies some portion of time, we introduce time into our investigations. See MECHANICS. DY'NASTY, n. s. Avvastía. Government; sovereignty.

Some account him fabulous, because he carries up the Egyptian dynasties before the flood, yea, and long before the creation. Hale's Origin of Mankind. Greece was divided into several dynasties, which our author has enumerated under their respective princes. Pope.

I was detained repairing shattered thrones, Marrying fools, restoring dynasties, Avenging men upon their enemies, And making them repent their own revenge. Byron. DYNASTY; from dvvasns, Gr. a sovereign; among ancient historians, signifies a race or succession of kings of the same family. Such were the dynasties of Egypt. The Egyptians reckon thirty dynasties within the space of 36,525 years;

but most chronologers look upon them as fab:lous.

DYRRACHIUM, in ancient geography, a town on the coast of Illyricum, before called Epidamnum, or Epidamnus, changed by the Romans to Dyrrachium; a name taken from the peninsula on which it stood. It was originally built by the Corcyreans, and, according to Pliny, was a Roman colony. It is famous in history: its port answered to that of Brundusiu.n, and the passage between them was very ready and expeditious. It was also a very celebrated mart for the people of the Adriatic; and the free admission of strangers contributed much to its in

crease.

DYSÆ, in the Saxon mythology, inferior goddesses, messengers of Woden, whose province it was to convey the souls of such as died in battle to his abode, called Valhalla, i. e. the hall of slaughter; where they were to drink with him and their other gods, cerevisia, a kind of ma't liquor, in the skulls of their enemies. The Dysæ conveyed those who died a natural death to Hela, the goddess of hell, where they were tormented with hunger, thirst, and every kind of evil.

DYSART, a royal borough in a parish of the same name, on the north shore of the Frith of Forth, three miles east of Kinghorn, and eleven north of Edinburgh. Its charter was granted about the beginning of the sixteenth century, and it is mentioned, at that time, as one of the principal trading towns in Fife. Before the middle of the eighteenth century, however, its trade had greatly declined, and it only began to revive about 1756. The church is very ancient, and is said to have been built by the Picts. The harbour is good, and the trade considerable; employing about thirty-six vessels in the coal and foreign trade. So early as 1483 salt was manufactured here and exported to Holland. The ship-building also employs a considerable number of hands. Dysart has a weekly market, and fairs in May, June, August, and November.

DY'SCRASY, n. s. Avokpaoia. An unequal mixture of elements in the blood or nervous juice; a distemperature, when some humor or quality abounds in the body.

In this pituitous dyscrasy of blood, we must vomit off the pituita, and purge upon intermissions.

Floyer on the Humours. DYS'ENTERY, n. s. Fr. dysenterie, from dvoEvTepía. A looseness, wherein very ill humors flow off by stool, and are also sometimes attended with blood.

From an unusual inconstancy of the weather, and perpetual changes of the wind from east to west, proceed epidemical dysenteries. Arbuthnot on Ais.

DYSENTERY, DYSENTERIA; from dʊç, difficulty, and εvrɛpa, the bowels. The flux. A genus of disease in the class pyrexia, and order profluvia ot Cullen's Nosology. It is known by contagious pyrexia; tenesmus; mucous stools, sometimes mixed with blood, the natural fæces being retained or voided in small hard scybala, loss of appetite, and nausea. It occurs chiefly in summer and autumn, and is often occasioned by much moisture quickly succeeding intense heat, whereby the perspiration is suddenly checked; but the cause which most usually gives rise to it, is a