History of Technology in India, Vol. I: From Antiquity to c. 1200 A.D. v1.c18.10

v1.c18.10

Then coming down to the classical age of Ayurvedic medicine again there are references of six metals only i.e. *suvarṇa* (Gold), *rajata* (Silver), *tāmra* (Copper), *kṛṣṇayasa* (Iron), *trapu* (Tin) and *śīsā* (Lead) alongwith *lohamala/mandura* (Rusted iron) or *lohamalas* (slag part of all the later five metals except gold). In this period these are included in *bhauma/pārthiva* group or in *trapvadi* group. Further, in this period number of metallic compounds are found referred to for internal uses to achieve *Rasāyana* as well as therapeutic effects. In this period metals are mostly used for obtaining Rasayana effects and less commonly for therapeutic effects. Their processing methods are also found described in this period though, from pharmaceutical point of view these may not be considered as very suitable in converting metals for internal use and probably for this reason only their uses are found very much limited. In this period the metals could be processed in such a way that these are reduced to collyrium like fine powder form or sometimes to solution form.