The Materia Medica of the Hindus, compiled from Sanskrit Medical Works c4.s7.t2.7

c4.s7.t2.7

Several methods of roasting orpiment are described. The *Bhávaprakása* recommends that orpiment should be powdered and made into a ball with the juice of *Boerhaavia diffusa* (*punarnavá*) and placed in the centre of a pot full of the ashes of that plant. The pot should be now covered with a dish, luted with clay, and heated over a fire for twenty hours. When cool the ball of roasted orpiment is taken out from the pot and reduced to powder. Another process is as follows. Take of purified orpiment and *yavakshára*, equal parts, rub them together with the juice of *Vitex Negundo* (*nirgundi*), and roast the mixture in a closed crucible. The resulting compound from both these processes is described as a white camphor-like substance.