1863.] 635 



acid. The precipitate which falls is collected on a filter, washed, 

 dried, and treated with boiling spirit of wine, which leaves a large 

 quantity of pectine undissolved. The munjistine which dissolves in 

 the alcohol is obtained in a pure state by repeated crystallizations in 

 the way already indicated. The first process which I have described 

 is, however, by far the best. The colouring matter of munjeet can 

 likewise be extracted with boiling solutions of alum ; but I find sul- 

 phate of alumina greatly preferable, as the alum, by its tendency to 

 crystallize, very much impedes the filtration of the liquids. I likewise 

 attempted to employ Professor E. Kopp's process with sulphurous 

 acid, which gives such excellent results with ordinary madder, but I 

 found it wholly inapplicable to munjeet. 



Munjistine, prepared by the processes described, when crystallized 

 out of alcohol, forms golden-yellow plates of great brilliancy. It is 

 but moderately soluble in cold, but dissolves pretty readily in boiling 

 water, forming a bright yellow solution, from which it is deposited 

 in flocks when the liquid cools. Saturated solutions almost gelati- 

 nize. It dissolves to some extent in cold, but more readily in boiling 

 spirit of wine, and is not precipitated by the addition of water. It 

 dissolves in carbonate of soda with a bright red colour. In ammonia 

 it forms a red solution with a slight tinge of brown : caustic soda 

 produces with it a rich crimson colour. Both its aqueous and 

 alcoholic solutions, when boiled with alumina, form beautiful flakes of 

 a bright orange colour, almost the whole of the munjistine being 

 withdrawn from solution. These flakes are soluble in a large excess 

 of caustic soda, with a fine crimson colour. Munjistine dyes cloth 

 mordanted with alumina a bright orange. With iron mordant it yields 

 a brownish-purple colour, and with Turkey-red mordant a pleasing 

 deep orange. These colours are moderately permanent, and bear the 

 application of bran and soap tolerably well. The munjistine sensibly 

 modifies the colours produced by munjeet, giving the reds a shade 

 of scarlet, as has been long observed. 



Commercial nitric acid dissolves munjistine with a yellow colour, 

 but does not appear to decompose it even on boiling. Fuming 

 nitric acid (1-5) dissolves munjistine in the cold, and on application 

 of heat decomposes it, no oxalic acid being produced. It readily 

 dissolves in cold sulphuric acid with a bright orange colour ; and the 

 solution may be heated nearly to boiling without blackening or 



