BRUSHES 547 



Walnut (Juglans regia) peelings, when ripe, contain a dark brown dyestuff, -which 

 communicates a permanent colour to wool. The older the infusion or decoction of 

 the peel, the better dye does it make. The stuff is dyed in the lukewarm bath, and 

 needs no mordant, though it becomes brighter with alum ; or this dye may be com- 

 bined with the madder or fustic bath, to give varieties of shade. For dyeing silk, 

 this bath should be hardly lukewarm, for fear of causing inequality of colour. 



The peelings of horse-chestnuts may be used for the same purpose : with muriate 

 of tin they give a bronze colour, and with acetate of lead, a reddish brown. 



Catechu gives cotton a permanent brown dye, as also a bronze and mordore, when 

 its solution in hot water is combined with acetate or sulphate of copper, or when the 

 stuff is previously mordanted with the acetates of copper and alumina mixed, some- 

 times with a little iron liquor, rinsed, dried, and dyed up, the bath being at a boiling 

 heat. 



Ferrocyanide of copper gives a yellow-brown or a bronze to cotton and silk. 



The brown colour called carmelite by the French is produced by 1 Ib. of catechu to 

 4 ozs. of verdigris, with 5 ozs. of muriate of ammonia. The bronze (solitaire) is given 

 by passing the stuff through a solution of muriate or sulphate of manganese, with a 

 little tartaric acid, drying, passing through a potash-ley at 4 Baum6, brightening and 

 fixing with solution of chloride of lime. 



These examples show in how many ways the browning of dyes may be modified, 

 upon what principles they are founded, and how we have it in our power to turn the 

 shade more or less towards red, black, yellow, blue, &c. 



Under the heads of different substances employed by the dyers will be found some 

 description of the methods employed for the purpose of extracting their colours. For 

 some good practical receipts, Love's ' Art of Cleaning, Dyeing, Scouring, and Finish- 

 ing,' may be consulted. 



BROWN HJEIKATXTE. See IBON ORES. 



BROWN 1 IRON 1 ORE, or Limonitc. See IBOK OSES. 



BROWN OCHRE. The soft and decomposed varieties of brown iron ore. 



BROWN SUGAR. Strictly, the common dark Muscovado sugar ; ordinarily, the 

 common varieties of West Indian sugar. See SUGAB. 



BROWSE. A metallurgical term for a variety of slag. 



BRTTCINE. (G 46 H 28 N 2 8 [C^H^M^O 4 ] ; syn. Canimarine, Vomicine.) A very 

 bitter and poisonous alkaloid accompanying strychnine in mix vomica and in the false 

 angustura bark (Brutia antidysenterica). It is somewhat less poisonous than strych- 

 nine, and, like that base, is used in the treatment of paralysis, but in rather larger 

 doses. Brucine is prepared by the same process as strychnine. C. G. W. 



BRUCITE. Native hydrate of magnesia. So called after Dr. Bruce, of New 

 York. This mineral accompanies other magnesia minerals in serpentine. It is 

 broad foliated, folia several inches square being easily obtainable, and either opaque, 

 silvery ' white, or translucent. Thomson gives its composition: magnesia, 66'67 ; 

 protoxide of manganese, 1'57; protoxide of iron, 1-18; lime, 0*19; water, 

 30-39 = 100. 



BRUNSWICK GREEN. An oxychloride of copper, used as a pigment. Copper 

 filings or turnings are moistened with a solution of sal-ammoniac, and left in contact 

 with the air. The oxychloride thus forms : it is washed off with water, and .dried at 

 a gentle heat. 



BRUSHES. (Brasses, Fr. ; Biirsten, Ger.) Since Mr. Mason introduced his 

 mode of securing the hairs in brushes, it has, in all the better class of brushes, been 

 very generally adopted. His patent dates 1830. 262 



Modified contrivances, partaking more or less of the 

 original conditions, have been introduced in the 

 manufacture. The principles of Mr. Mason's in- 

 vention and its subsequent modifications consist in 

 a firmer mode of fixing the knots, or small bundles, 

 of hair into the stock or the handle of the brush. 

 This is done by forming grooves in the stocks of the 

 brushes for the purpose of receiving the ends of 

 the knots of hair, instead of the holes drilled into 

 the wood, as in brushes of the common construc- 

 tions. These grooves are to be formed like a 

 dovetail, or wider at the bottom than the top ; and 

 when the ends of the knots of hair have been dipped 

 into cement, they are to be placed in the grooves 264 



and compressed into an oval form, by which the 

 ends of the hair will be pressed outwards, into tho recess or wider part of the dovetailed 

 groove ; or the grooves may be formed with threads or teeth on the sides, instead of 



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