THE ELECTROLYTIC REFINING OF BASE LEAD BULLION (TITUS ULKE) 270 ELECTROLYTIC LEAD REFINING (ANSON G. BETTS) 274 PART X SMELTING WORKS AND REFINERIES THE NEW SMELTER AT EL PASO, TEXAS (EDITORIAL) 285 NEW PLANT OF THE AMERICAN SMELTING AND REFINING COMPANY AT MURRAY, UTAH (WALTER RENTON INGALLS) 287 THE MURRAY SMELTER, UTAH (O. PUFAHL) 291 THE PUEBLO LEAD SMELTERS (O. PUFAHL) 294 THE PERTH AMBOY PLANT OF THE AMERICAN SMELTING AND REFINING COMPANY (O. PUFAHL) 296 THE NATIONAL PLANT OF THE AMERICAN SMELTING AND REFINING COMPANY (O. PUFAHL) 299 THE EAST HELENA PLANT OF THE AMERICAN SMELTING AND REFINING COMPANY (O. PUFAHL) 302 THE GLOBE PLANT OF THE AMERICAN SMELTING AND REFINING COMPANY (O. PUFAHL) 304 LEAD SMELTING IN SPAIN (HJALMAR ERIKSSON) 306 LEAD SMELTING AT MONTEPONI, SARDINIA (ERMINIO FERRARIS) 311 PART I NOTES ON LEAD MINING SOURCES OF LEAD PRODUCTION IN THE UNITED STATES BY WALTER RENTON INGALLS (November 28, 1903) Statistics of lead production are of value in two directions: (1) in showing the relative proportion of the kinds of lead produced; and (2) in showing the sources from which produced. Lead is marketed in three principal forms: (_a_) desilverized; (_b_) soft; (_c_) antimonial, or hard. The terms to distinguish between classes “a” and “b” are inexact, because, of course, desilverized lead is soft lead. Desilverized lead itself is classified as “corroding,” which is the highest grade, and ordinary “desilverized.” Soft lead, referring to the Missouri product, may be either “ordinary” or “chemical hard.” The latter is such lead as contains a small percentage of copper and antimony as impurities, which, without making it really hard, increase its resistance against the action of acids, and therefore render it especially suitable for the production of sheet to be used in sulphuric-acid chamber construction and like purposes. The production of chemical hard lead is a fortuitous matter, depending on the presence of the valuable impurities in the virgin ores. If present, these impurities go into the lead, and cannot be completely removed by the simple process of refining which is practised. Nobody knows just what proportions of copper and antimony are required to impart the desired property, and consequently no specifications are made. Some chemical engineers call for a particular brand, but this is really only a whim, since the same