BRAZIL WOOD DYES 4^5 



which give them a purple hue ; and there are several processes in which tho alkalis, 

 oithor fixed or volatile, are used for forming violets and purples. But tho colours 

 obtained by these methods, -which may bo easily varied according to tho purpose, are 

 perishable, and possess but a transient bloom. The alkalis appear not to injure the 

 colours derived from madder, but they accelerate the destruction of most other 

 colours. 



In England and Holland the wood-dyes are reduced to powder by means of mills 

 erected for the purpose. 



The bright fugitive red, called fancy red, is given to cotton of Nicaragua, or peach 

 wood, a cheap kind of Brazil wood. See PEACH WOOD. 



The cotton being scoured and bleached, is boiled with sumach. It is then impreg- 

 nated with a solution of tin (at 5 B., according to Vitalis). It should now be washed 

 slightly in a weak bath of the dyeing wood ; and, lastly, worked in a somewhat stale 

 infusion of the peach or Brazil wood. When the temperature of this is lukewarm, the 

 dye is said to take better. Sometimes two successive immersions in the bath are 

 given. It is now wrung out, aired, washed in water, and dried. 



M. Vitalis says, that his solution of tin is prepared with two ounces of tin and 

 a pound of aqua regia, made with two parts of nitric acid at 24 B. and three parts 

 of muriatic acid at 22. 



For a rose colour, the cotton is alumed as usual, and washed from tho alum. It 

 then gets tho tin mordant, and is again washed. It is now turned through the dye- 

 bath, an operation which is repeated if necessary. 



For purple, a little alum is added to the Brazil bath. 



1 . For amaranth, the cotton is strongly galled, dried, and washed. 



2. It is passed through the black cask (tonncau noir~), till it has taken a strong 

 grey shade. See BLACK DTE. 



3. It receives a bath of lime water. 



4. Mordant of tin. 



5. Dyeing in the Brazil wood bath. 



6. The last two operations are repeated. 



Dingier has endeavoured to separate the colouring matter of the different sorts of 

 Brazil wood, so as to obtain the same tint from the coarser as from the best Pernam- 

 buco. His process consists in treating tho wood with hot water or steam, in concen- 

 trating the decoction so as to obtain 14 or 15 pounds of it from 4 pounds of wood, 

 allowing it to cool, and pouring into it two pounds of skim milk ; agitating, then 

 boiling for a few minutes, and filtering. The dun'colouring matters are precipitated 

 by the coagulation of the caseous substance. For dyeing, tho decoctions must be 

 diluted with water; for printing, they must be concentrated so that 4 pounds of wood 

 shall furnish only 5 or 6 pounds of decoction, and tho liquor may be thickened in the 

 ordinary way. These decoctions may be employed immediately, as by this treatment 

 they have acquired the same property as they otherwise could get only by being long 

 kept. A slight fermentation is said to improve tho colour of these decoctions ; some 

 ground wood is put into the decoction to favour this process. 



Gall-nuts, however, sumach, the bark of birch or alder, renders tho colour of Brazil 

 wood more durable upon alumed linen and cotton goods, but the shade is a little 

 darker. 



In dyeing wool with Pernambuco Brazil wood, the temperature of the bath should 

 never be above 150 F., since higher heats impair the colour. 



According to Dingier and Kurrer, bright and fast scarlet reds may be obtained 

 upon wool, by preparing a decoction of 50 pounds of Brazil wood in three successive 

 boils, and setting tho decoction aside for 3 or 4 weeks in a cool place ; 100 pounds of 

 the wool are then alumed in a bath of 22 pounds of alum and 1 1 pounds of tartar, 

 and afterwards rinsed in cold water. Meanwhile, we fill two-thirds with water a 

 copper containing 30 pails, and heated to the temperature of 150-* or 160 F. We 

 pour in 3 pailfuls of tho decoction, heat to tho same point again, and introduce 30 

 pounds of wool, which does not take a scarlet, but rather a crimson tint. This being re- 

 moved, 2 pails of decoction are put in, and 30 pounds of wool, which becomes scarlet, 

 but not so fine as at tho third dip. If the dyer strengthens the colour a little at the 

 first dip, a little more at the second, and adds at the third and fourth the quantity of 

 decoction merely necessary, he will obtain an uniform scarlet tint. With 50 pounds 

 of Pernambuco, 1,000 pounds of wool may bo dyed scarlet in this way, and with the 

 deposits another 100 may be dyed of a tile colour. An addition of weld renders the 

 colour faster, but less brilliant. See WELD. 



Karkutsch says tho dye may be improved by adding some ox -gall to the bath. 



In dyeing cotton, the tannin and gallic acid are two necessary mordants ; and the 

 colour is particularly bright and durable when tho cloth has been prepared with the 

 oily process of Turkey red. 



