“Indian yellow used to be produced by feeding cows mango leaves and using the colour produced in the urine to make the paint pigment!
The practice was outlawed in 1908 due to malnutrition of the cows”
However that is just a tall tale, which I suppose might have made it seem more enigmatic to Avante garde artists, and small children than it is, as it's much more likely to have come from a plant.
So off to find some other believable sources of information:
...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.
Memecylon tinctorium (ironwood tree)
Also used for
- like tumeric which can also dye everything it touches a bright yellow -
And the chemist John Stenhouse published his accounts of an examination of a purree ball in The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, third series, November 1844 Philosophical magazine. He noted that his 85g sample, which had been imported from India and China, showed small needle-shaped crystals when viewed under a microscope, and smelled distinctly of castor oil. He concluded that Indian Yellow was not in fact cattle urine. It was instead either the collected gallstones of various animals (including but not limited to camels, elephants and buffalos); or alternatively it was of a vegetable origin, created from:
… 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.
The magnesium coming from bovine urine!
Now that was interesting wasn't it?!
Oh and Van Gogh is reported to have used it in his painting The starry night.