This section is from the book "Chromatography; Or, A Treatise On Colours And Pigments, And Of Their Powers In Painting", by George Field. Also available from Amazon: Chromatography, or A Treatise on Colours and Pigments, and of Their Powers in Painting.
Cassia Fistula is a native vegetal pigment, though it is more commonly used as a medicinal drug. It is brought from the East and West Indies in a sort of cane, in which it is naturally produced. As a pigment it is deep, transparent, and of an imperfect citrine colour, inclining to dark green - diffusible in water, without grinding, like gamboge and sap-green; it is, however, little used as a pigment, and that only in water, as a sort of substitute for bistre: which sec.