This outline of the metallurgy of the common metals, namely, gold, silver, iron, copper, lead, and zinc, is devoted to the description of the processes of winning the metals from their ores and to the refining of these metals, except iron, the metallurgy of which is treated only to the point where pig iron is obtained.<br><br>Following the description of ores, as well as of the fuels used in treating them, and the materials of which the furnaces are composed, we come to their sampling, for the determination of their exact value before treatment.<br><br>A chapter has been devoted to the subject of thermo-chemistry as applicable to igneous methods of extraction.<br><br>The winning or reduction of the various metals is then taken up in order and is followed by a description of the methods of refining them.<br><br>Attention is then given to commercial considerations, since the processes must be conducted in a profitable way.<br><br>The author is indebted to Mr. F. L. Bosqui, who has not only read the manuscript, but has modified the portion devoted to the cyaniding of gold and silver ores, as his special knowledge has justified.<br><br>For the subject matter relating to the smelting of silver-lead and copper ores, the author has drawn on his own experience, gained during upwards of a quarter of a century of practical work.