The cleaning and electro-plating of metals;

This reproduction was printed from a digital file created at the Library of Congress as part of an extensive scanning effort started with a generous donation from the Alfred P. Sloan Foundation. The Library is pleased to offer much of its public domain holdings free of charge online and at a modest price in this printed format. Seeing these older volumes from our collections rediscovered by new generations of readers renews our own passion for books and scholarship.