Indian yellow

After application Indian yellow produced a clear, deep and luminescent orange-yellow color which, due to its fluorescence, appears especially vibrant and bright in sunlight.

Studies in 2018 of a sample collected by T. N. Mukharji in 1883 give credibility to his observations that it was obtained from concentrated urine from cows fed on a diet of mango leaves.

[11] Indian yellow pigment is claimed to have been originally manufactured in rural India from the urine of cattle fed only on mango leaves and water.

[13] A description of the above process was given by T. N. Mukharji of Calcutta, who in response to a request from Sir Joseph Hooker, investigated an animal source in Monghyr, north-east Bihar, India.

The latter was of special interest and he noted how cows were fed with mango leaves, suffered from the poor nutrition, with the sparse urine having to be collected in small pots, cooled, and then concentrated over a fire.

[15] The Art of Painting in Oil and Fresco,[16] a translation of the French De la peinture à l’huile by Léonor Mérimée, states a possible source for the pigment: ...the coloring matter is extracted from a tree or large shrub, called Memecylon tinctorium, the leaves of which are employed by the natives in their yellow dyes.

From a smell like cow's urine, which exhales from this colour, it is probable that this material is employed in extracting the tint of the memecylon.In 1844, chemist John Stenhouse examined the origin of Indian yellow in an article published in the November 1844 edition of the Philosophical Magazine.

He carried out a chemical analysis and concluded that he believed it was in fact of vegetable origin, and was "the juice of some tree or plant, which, after it has been expressed, has been saturated with magnesia and boiled down to its present consistence.

Pigment sample