BRAZIL WOOD.

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by Bolley for bresiline leads to the conclusion that bresiline and hsematoxylinonly differ by the elements of phenol—

Bresiline.C22H20O7

Hsematoxylin. Ci6H I4 C>6

Difference.CcHeO = Phenol.

Some authors hold the opinion that bresiline and hsematoxylin are identical,but though there exist a great analogy between these substances they are notidentical, as is proved, moreover, by practice on the large scale as well asby recent chemical researches. Hsematoxylin when adted upon by nitric acidyields only oxalic acid, whereas bresiline under the same conditions yieldstrinitro-phenic or picric acid. Brazil wood, or the colouring matter containedtherein, is employed in dyeing in the following conditions :—

1. The wood itself, either reduced to shavings, raspings, or powder, servesfor the production of red, rose-red, amaranth colour, and carmine-red ; some-times the wood is mixed in smaller or larger proportion with garancin for thedyeing of the so-called garancin colours. The wood is used in a mechanicallydivided state for the preparation of the decodtion and concentrated extradts.

2. Decodtion, or liquor of Brazil wood, obtained by boiling by means ofsteam the raspings of the wood with from 18 to 20 times its weight ofwater, or by the exhaustion of the wood by displacement with boiling water.This liquor is used for dyeing, for the preparation of concentrated extradls,and for the manufacture of the Brazil lakes.

3. The concentrated extradts having a sp. gr. of 1*075, i , ii6, 1*162, oreven evaporated down to solidity. In these states the dye is more convenientfor carriage, whence the employment of such extradts is rather increasing.The mode of preparation of these and similar extradts will be fully describedin a separate chapter. It need hardly be said that the quality of these extradtsvaries greatly, not only in respedt of the richness of the colouring mattertherein contained, but also as regards the purity and freshness of the shadesproduced; these differences depend partly upon the kind of wood used, andpartly also upon the care taken to prevent oxidation during the process.

4. Lakes, of which there are a great variety, made with Brazil wood, knowncommercially by various names, as, for instance, Venice ball lake, Vienna,Florentine, Berlin, and New lakes; they are chiefly used for the preparationof coloured paper, for printing paper-hangings, and by artists, decorators, andcarriage painters. The mode of manufacture of these and other lakes willalso occupy our attention more fully hereafter.

Bresiline belongs to that class of pigments which cannot be fixed upon anykind of textile fibre, except by the aid of a mordant, which, in this instance,just as in the case of madder, not only fixes the pigment, but also determinesand develops the shade. With a piece of cotton previously mordanted withalumina, hydrated oxide of iron, or a mixture of the two, we obtain withbresiline, or any preparation of Brazil wood, colours which to some extentresemble those produced by madder, or rather by cochineal. The aluminamordants will produce red or rose-reds; the iron mordants, a greyish violet orblack ; the mixture of alumina and iron mordants yields a brown. Binoxide oftin again yields red; the black is nothing very particular ; the violet absolutelyu giy; the reds and roses are temporarily brilliant, but soon become dull, and

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