3. On the Colouring Matter of the Rottlera tinctoria

Extract

The Rottlera tinctoria is a large tree which is found distributed over the whole Indian peninsula, and is particularly abundant in the hill jungles of Mysore, Canara, and Malabar. The fruit, which is about the size of a pea, is covered with curious stellate hairs and red glands, which are easily separated by rubbing, and form without further preparation the colouring matter which is sold in the bazaars. It is a perfectly uniform brick-dust coloured powder, which repels water, and is scarcely soluble in that fluid. Alcohol and ether extract a red colouring matter, as do also the alkalies and their carbonates.