a well known colour, supposed to be owing to the absence of light; all the rays thereof being ab- sorbed by the black bodies. See Optics.

Black, among dyers, one of the five simple and mother colours used in dying. It is made differently, ac- cording to the several qualities of the stuffs that are to be dyed. For stuffs of a high price, as woollen cloth an ell and a half or an ell and a quarter wide, broad and narrow rattens, fine woollen druggets, &c. they must use a black made of the best woad and indigo, inclining to a bluish brown. The goodness of the composition consists in there being not above six pounds of indigo ready prepared to each ball of woad, when the latter, being in the tub, begins to cast its blue flower; and in not being heated for use above twice; after which it must be boiled with alum, tartar, or ashes of lees of wine, then maddered with common madder, and lastly the black must be given with gall- nuts of Aleppo, copperas, and sumach. As for more indifferent stuffs, such as small rattens, and thallos, as they cannot pay for the expense of madderding it is sufficient that they be well boiled with woad, and after- wards blacked with gall and copperas. There is like- wise jesuits black, which is made with the same ingre- dients as the good black, but without having first dyed the stuff blue.

German Black, called by some Frankfort black, is made with the lees of wine, burnt, washed afterwards in water, then ground in mills made for that purpose, with ivory, bones, or peach-stones, also burnt. It comes from Frankfort, Mentz, and Strasbourg, either in lumps or powder, and must be chosen moist, without having been wetted, of a fine shining black, soft, fri- able, light, and with as few shining grains as possible.

Ivory Black, otherwise called velvet black, is burnt ivory, which becoming quite black, and being reduced to thin plates, is ground in water, and made into tro- ches, to be used by painters, and by jewellers, who set precious stones, to blacken the ground of the col- lets, and give the diamonds a teint or foil. In order to be good, it ought to be tender, friable, and tho- roughly ground.

Bone-Black is made with the bones of oxen, cows, &c. and is used in painting; but is not so much esteemed as ivory black.

Hart's-Black, that which remains in the retort after the spirits, volatile salt, and oil, have been extracted from hart's-horn. It answers the purposes of painters almost as well as ivory-black.

Spanish Black is nothing but burnt cork: It is used in several works. It should be light, and have as few grains of sand mixed with it as possible.

Lamp-Black, or Lam-Black, the footy smoke of ro- sin. There is some in powder and some in lumps, and is mostly brought from Sweden and Norway, and pays duty £1. 10s. 4½d. the hundred weight. It is used on various occasions, particularly for making the print- er's ink, for which purpose it is mixed with oil of wal- nuts, or linseed, and turpentine, all boiled together.

Earth-Black, a sort of coals found in the ground, with which the painters and limners use to paint in fresco, after it has been well ground. There is also a black made with gall nuts, copperas, or vitriol, such as common ink. And a black made with silver and lead, which serves to fill up the cavities of ingrained things.

Currier's Black, a black made with gall-nuts, sour beer, and old iron, termed the first black. The second black, which gives the glofs to the leather, is composed of gall-nuts, copperas, and gum-arabic.

Black-bank, in geography, a town of Ireland, about seven miles south of Armagh, in $6^\circ 50'$ W. long. and $54^\circ 12'$ N. lat.

Black-berry, in botany. See Rubus.

Black-book of the exchequer. See Exchequer.

Black-burn, a market-town of Lancashire, about nine miles east of Preston, in $2^\circ 20'$ W. long. and $53^\circ 40'$ N. lat.

Black-cap, in ornithology, the English name of the muscicapula utricapilla. See Muscicapa.

Black-eagle. See Falco.

Black-forest, a part of Swabia, divided from Switzerland by the river Rhine.

Black-game. See Tetrao.

Black-mail, a link of mail, or small pieces of metal or money. In the counties of Northumberland, Cumberland, Westmoreland, and several parts of Scotland, it was formerly taken for a certain rent of money, corn, cattle, or other consideration, paid by poor people near the borders, to persons of note and power, allied with some moss-troopers, or known robbers, in order to protect them from pillage.

Black-order. See Order.

Black-root. See Rod.

Black-sea, the same with the Euxine sea, lying north of Natolia, between $29^\circ$ and $44^\circ$ E. long. and $42^\circ$ and $46^\circ$ N. lat.

Black-tin. See Tin.

Black-water, the name of two rivers in Ireland; one of which runs through the counties of Cork and Waterford, and falls in Youghal bay; and the other after watering the county of Armagh, falls into Lough Neagh.

Blacks, in physiology. See Negroes.

Bladder, in anatomy. See p. 269, col. 2.

Air-bladder, in physiology. See Air.

Oil-bladders. See Oil.

Blæria, in botany, a genus of the tetrandria monogynia clas. The calyx is divided into four segments, as also the corolla; the stamens are inserted into the receptacle; and the capsule has four cells, containing many seeds. There is but one species, viz. the criocides, a native of the cape of Good Hope.

Blafart, in commerce, a small coin, current at Cologn, worth something more than a farthing of our money.

Blain, among farriers, a distemper incident to beasts, being a certain bladder growing on the root of the tongue, against the wind-pipe, which swells to such a pitch as to stop the breath. It comes by great chafing and heating of the stomach, and is perceived by the beast's gaping and holding out his tongue, and foaming at the mouth. To cure it, cast the beast, take forth his tongue, and then, slitting the bladder, wash it gently with vinegar and a little salt.

Blair, of Athol, a small town of Athol in Scotland, situated about twenty-eight miles north of Perth.

Blairia, in botany. See Verbena.

Blakea, in botany, a genus of the dodecandra monogynia clas. The calyx has five leaves; the petals are six; the antherae are connected; and the capsule has six cells. There is only one species, viz. the trinervia, a native of Jamaica.

Blamont, a town of Lorrain, about twenty-eight miles south-east of Nancy, in E. long. $6^\circ 45'$ and N. lat. $48^\circ 33'$.

Blanc. See Blank.

Blanch-holding, in Scots law, a tenure by which the vassal is only bound to pay an elusory yearly duty to his superior merely as an acknowledgment of his right. See Scots Law, tit. The several kinds of holdings.

Carte-Blanche. See Carte.

Blanching, in a general sense, denotes the art of bleaching or whitening.

Blanching of copper is done various ways, so as to make it resemble silver. If it be done for sale, it is felony by 8 and 9 William III. chap. xxvi.

Blanching, in coinage, the operation performed on the planchets or pieces of silver, to give them the requisite lustre and brightness. They also blanch pieces of plate, when they would have them continue white, or have only some parts of them burnished.

Blanching, as it is now practised, is performed by heating the pieces on a kind of peel with a wood fire, in the manner of a reverberatory; so that the flame passes over the peel. The pieces being sufficiently heated and cooled again, are put successively to boil in two pans, which are of copper: in these they put water, common salt, and tartar of Montpelier. When they have been well drained of this water in a copper sieve, they throw sand and fresh water over them; and when dry, they are well rubbed with towels.

Blanching, among gardeners, an operation whereby certain sallets, roots, &c. are rendered whiter than they would otherwise be.

It is this: After pruning off the tops and roots of the plants to be blanched, they plant them in trenches about ten inches wide, and as many deep, more or less, as is judged necessary; as they grow up, care is taken to cover them with earth, within four or five inches of their tops: This is repeated from time to time, for five or six weeks, in which time they will be fit for use, and of a whitish colour where covered by the earth.

Blanching also denotes the operation of covering iron plates with a thin coat or crust of tin.

Blanco, or Cape-Blanco, a promontory of Peru, in S. America, W. long. $81^\circ$, and S. lat. $3^\circ 45'$. Blanco is also the name of one of the Antille-islands, on the coast of Terra Firma, in W. long. $64^\circ$, and N. lat. $12^\circ$.

Cape-Blanco is also a promontory of Africa, in $18^\circ$ W. long. and $20^\circ$ N. lat.

Blanford, a market town of Dorsetshire, ten miles north north of Pool, in $2^\circ 30'$ W. long. and $50^\circ 50'$ N. lat.