Haematoxylin or hematoxylin, also called natural black 1 or C.I. 75290, is a compound extracted from heartwood of the logwood tree with a chemical formula of C16H14O6. This naturally derived dye has b

Phosphotungstic acid or tungstophosphoric acid, is a heteropoly acid with the chemical formula H3. It forms hydrates H3·nH2O. It is normally isolated as the n = 24 hydrate but can be desiccated to the