The object in writing the following pages has been to present the reader with a thoroughly practical account of the simplest and most accurate methods of recovering the gold, silver, and platinum from the sundry waste liquid residues of goldsmiths, silversmiths, and other workers in the precious metal trades, and thereby provide a long felt want for the direct guidance of practical men engaged in the different kinds of manufacturing establishments wherein the precious metals are employed.<br><br>The text-books, as yet published, barely touch this subject, for, speaking generally, they only treat the matter from a hypothetical standpoint, and such information is altogether insufficient for service in the large precious metal manufactories wherein the manipulatory art of ornamental construction is taught and practised.<br><br>This book is written by a practical man, for practical men employed in the different branches of the precious metal industries of the nation, and the author has given full detailed descriptions of the processes and formulas, with illustrations of the apparatus to be severally employed in extracting the waste metals from all kinds of liquids, so as to make the book of special value to all concerned in the manufacture of jewellery and other kindred wares.