BREZILIN. 929 



M. Chevreul,* who first distinguished it. It is sometimes so 

 abundant as to exist in the wood in large crystals. The rasped 

 or chopped wood is exhausted by means of water of a tempera- 

 ture between 122 and 131, the solution evaporated to dryness 

 by a water bath, the residue lixiviated with alcohol of 0.843 

 density, and the filtered solution distilled to a syrup, from which 

 after the addition of a little water the hematoxylin is gradually 

 deposited. 



It crystallizes in reddish yellow scales, soluble in 1000 times 

 their weight of water, dissolving easily in alcohol and ether. 

 Acids in small quantity make it yellow, in large quantity red. 

 The alkaline bases impart to a solution of hematoxylin a 

 violet, purple or blue colour. Its decoction is deprived of 

 colour by sulphuretted hydrogen (which has the same action on 

 litmus,) and by nascent hydrogen ; much of the hematoxylin 

 probably exists in this state in the wood and acquires colour 

 in the course of its application as a dye. Cloth impregnated 

 with alumina is dyed black in a decoction of logwood, and of 

 a fine brown in a mixture of logwood and madder. It enters 

 into the materials for dyeing hats and broad cloth black ; the 

 effect of an acid in staining them red is due to its presence. 

 By dry distillation hematoxylin yields ammonia, proving that 

 it contains nitrogen. 



BREZILIN. 



This name has been applied by Chevreul to the colouring 

 matter of Brazil wood, which comes to this country from 

 Brazil and Pernarnbuco, and is the wood of several species of 

 Ccesalpina. It is obtained by similar processes with the pre- 

 ceding colouring matters. 



Brezilin crystallizes in orange prisms, soluble in water and 

 alcohol. Acids give it a yellow colour ; with citric acid the 

 yellow is particularly fine. When neutralised with alkali it 

 becomes again of a fine red, but with an excess of alkali violet 

 or blue. In the tree it is nearly colourless, owing to the presence 

 of free acid, and its fine red colour does not appear till all the 

 acid which it naturally contains is saturated. This saturation 

 is generally effected by sprinkling the ground wood with a 



* Ann. de Chim. et de Phys., t. 81, p. 128. 



2 P P 



