ASSAYER'S GUIDE; OR, PRACTICAL DIRECTIONS TO ASSAYERS, FOR THE TESTS AND ASSAYS, BY HEAT AND BY WET PROCESSES. OF THE ORES OF ALL THE PRINCIPAL METALS, OF GOLD AND SILVER COINS AND ALLOYS, BY OSCAR M. LIEBER, LATE GEOLOGIST TO THE STATE OF MISSISSIPPI PHILADELPHIA: HENRY CAREY BAIRD & CO., 810 WALNUT STREET. |