Gold and mercury

[Richard P Hayes]

> I urgently need the following information and I will be extremely grateful
> for any help:
> 1. In ancient India, how was "new" gold obtained, i.e. by mining, panning
> etc?
> 2. Do we know the general quality of that mined/panned gold? Some newly
> obtained gold is relatively a pure metal, other gold has to be purified by
> various chemical and heating methods.

Owing to being in a rush, I cannot check the precise sources for you
now, but I recall seeing discussion in Dharmakiirti's Pramaa.navaartika
in the Pramaa.na-siddhi chapter where there is some reference to the
role of mercury in refining gold. Not being a metallurgist, I was unable
to understand what exactly was being done but did eventually find some
explanations in some books my father (who is a geologist) had on his
shelf. As I recall, the process involves mixing mercury with heated
or pulverized gold ore; small particles of gold dust adhere to the
mercury and can then be precipitated out. My memory is dim on the
details. Indeed, my whole mind is dim on nearly everything. If this
reference in Dharmakiirti is something you'd like to pursue, please
contact me next week after I return from the AAR. Or ask John Dunne,
also at Harvard. He knows lots of mostly useless things.

Richard Hayes (cxev at musica.mcgill.ca)