Page:Transactions of the Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne 1838 Vol.2.djvu/161

Rh 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 colouring 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.