Assayer's Guide; Or, Practical Directions To Assayers, Miners, And Smelters

For The Tests And Assays, By Heat And Wet Processes, Of The Ores Of All The Principal Metals, Of Gold And Silver Coins And Alloys, And Of Coal, &C » 

For The Tests And Assays, By Heat And Wet Processes, Of The Ores Of All The Principal Metals, Of Gold And Silver Coins And Alloys, And Of Coal, &C «