Minerals and Metals in Ancient India v2.c44.s1.13

v2.c44.s1.13

Suśruta recommended as drugs, the oxides (calces) of tin, lead, copper, silver, iron and gold which were prepared by roasting the metals with minerals like alum-earth and red ochre. For the roasting of iron, thin leaves of the metal were smeared with the levigated powder of the salts including common salt, saltpetre, sulphate of magnesia, and heated in the fire of cow-dung cakes. This process, called *ayaskrti*, affected the metal and produced oxides and oxy-salts. Mercury was not well-known during Suśruta’s time. Two types of pyrites (*mākṣika*) known to ‘resemble gold and silver’ were evidently chalcopyrite and ordinary iron-bearing pyrite. Compounds of arsenic (*phenasama bhasma*) and orpiment were recognised as poisons.