Copper. Progress reports, Metallurgical Division: 18, Studies in metallurgy of copper, Distribution of manganese between matte and slag in smelting of copper, by F. S. Wartman, G. M. Potter, and M. D. Schmid; Graphic representation of ratio of manganese distribution between matte and slag, by Merle D. Schmid; Experiments in flash-roasting of copper concentrates, by F. S. Wartman and others.