History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c20.s2.t4.5

v1.c20.s2.t4.5

Apart from the Sanskrit texts dealing with alchemy in ancient India, a few Tibetan texts also furnish some information on the chemical process of colouring metals with organic and inorganic dye-stuffs. *Bilva* (wood apple), *dāḍima* (pomegranate) and a special kind of dye (*smantshos*) are to be burnt and mixed with sour wine in a copper pot for three days. In this manner, a paint will be prepared which should be applied twenty one times to a thin piece of iron and it becomes copper (copper coloured) [*Dhātuvāda*, 2,3, vide Ray] for Extracts.