Part 2 - Purification of copper

First process.

Copper is purified and freed from the five defects referred to above, if it is melted with ksharas, amlas, and gairika by means of a fire of cowdung cakes, and then immersed in butter milk prepared out of buffalo’s milk, the process being performed for seven times.

Second process.

Leaves of copper, freed from alloys, are purified medicinally, if they are smeared with rock salt, rubbed with lime juice, heated, and then immersed into gruel made of barley, the process being performed for eight times.

Third process.

Leaves of copper are purified, if they are smeared with lime juice mixed with saltpetre, heated, and then immersed in the juice of nirgundi, the process being performed for eight times.

Fourth process.

Copper leaves are purified, if they are boiled with cow’s urine for three hours on a strong fire.

Fifth process.

See process two page 242.

Sixth process.

Copper leaves are to be heated and immersed in the juice of nirgundi, after having been smeared with the milks of snuhi and arka, salt, and kanji. The process is to be repeated for 12 times. The leaves are then to be smeared again with chalk, and salt, rubbed with butter milk, heated, and while still hot, to be immersed in the juice of nirgundi, rubbed with a sour vegetable juice. This last process is to be performed for six times. This is how copper is purified.