Mr. Trevelyan on a peculiar Colouring Matter. 151 



and in alcohol, and to paper stained by these solutions, the original 

 colour is restored by nitric, muriatic, sulphuric, tartaric, acetic, and 

 arsenic acids ; the three latter of which have no effect on the green co- 

 louring matter in the wood, or on its solution in nitric acid or in alcohol ; 

 the sulphuric acid gradually decomposes it, becoming of a dark colour. 



This paper was accompanied with specimens of the Wood, and of 

 the solution of the colouring matter in nitric acid. 



Since writing the above observations, I find the green solution in 

 nitric acid, after keeping for a few months, gradually loses its colour. 



W. C. T. 



VOL. II. R r 



