Field Testing for Gold and Silver: A Practical Manual for Prospectors and Miners. E-book. Formato PDF William Hamilton Merritt   -  Forgotten Books, 2017  - 

The more I worked with prospectors the more convinced I became that the usual blow-pipe sets prepared for colleges, etc., were much too complicated and too expensive for the field, and that a simpler and cheaper set of apparatus was desirable. How this want may be met I have endeavoured to show in the following pages. I do not claim, nor could I claim, any originality for the pan-amalgamation process, but by introducing a cheap and effective little balance, the procedure.