An edition of Discovery of subterraneall treasure (1639)

A discovery of subterranean treasure

viz. all manner of mines & minerals, from the gold to the coal, with plain directions and rules for finding them in all kingdoms and countries; also the art of melting, refining and assaying them made plain and easy to every ordinary capacity, so that they may with small charge try the value of such ores as shall be found either by rule or accident: to which is added, a real experiment, to try whether a piece of gold be true or counterfeit ...

By Gabriel Plattes