Gamboge


Gamboge is a partially transparent deep saffron to mustard yellow pigment. It is used to dye Buddhist monks' robes because it resembles the traditional colour used for the robes of Theravada Buddhist monks. It was this pigment that was used to prove Brownian motion by the physicist Jean Perrin in 1908.

Production

Gamboge is most often extracted by tapping resin from various species of evergreen trees of the family Clusiaceae. The tree most commonly used is the gamboge tree, including G. hanburyi, G. morella, and G. elliptica and G. heterandra. The orange fruit of Garcinia gummi-gutta is also known as gamboge or gambooge.
The trees must be at least ten years old before they are tapped. The resin is extracted by making spiral incisions in the bark, and by breaking off leaves and shoots and letting the milky yellow resinous gum drip out. The resulting latex is collected in hollow bamboo canes. After the resin is congealed, the bamboo is broken away and large rods of raw gamboge remain.

Uses

The pigment first reached Europe in early 17th century, and was used by artists such as Rembrandt, J.M.W. Turner, and Sir Joshua Reynolds. William Hooker mixed it with Prussian blue to create Hooker's Green. By the early 20th century it was replaced by a synthetic, more lightfast pigment, aureolin; however Winsor & Newton continued to sell the resin form until 2005.
Gamboge has strong laxative properties. Small doses are sufficient to produce watery feces, while large doses can be fatal.

Etymology

The word comes from gambogium, the Latin word for the pigment, which derives from Gambogia, the Latin word for Cambodia. Its first recorded use as a colour name in English was in 1634.