The reader who may be interested in following up this subject will find references to all the literature in the summary by Helen R. Hosmer, of the Research Laboratory of the General Electric Company, in the _Journal of Industrial and Engineering Chemistry_, New York, for April, 1917. Bucher's paper may be found in the same journal for March, and the issue for September contains a full report of the action of U.S. Government and a comparison of the various processes. Send fifteen cents to the U.S. Department of Commerce (or to the nearest custom house) for Bulletin No. 52, Special Agents Series on "Utilization of Atmospheric Nitrogen" by T.H. Norton. The Smithsonian Institution of Washington has issued a pamphlet on "Sources of Nitrogen Compounds in the United States." In the 1913 report of the Smithsonian Institution there are two fine articles on this subject: "The Manufacture of Nitrates from the Atmosphere" and "The Distribution of Mankind," which discusses Sir William Crookes' prediction of the exhaustion of wheat land. The D. Van Nostrand Co., New York, publishes a monograph on "Fixation of Atmospheric Nitrogen" by J. Knox, also "TNT and Other Nitrotoluenes" by G.C. Smith. The American Cyanamid Company, New York, gives out some attractive literature on their process. "American Munitions 1917-1918," the report of Benedict Crowell, Director of Munitions, to the Secretary of War, gives a fully illustrated account of the manufacture of arms, explosives and toxic gases. Our war experience in the "Oxidation of Ammonia" is told by C.L. Parsons in _Journal of Industrial and Engineering Chemistry_, June, 1919, and various other articles on the government munition work appeared in the same journal in the first half of 1919. "The Muscle Shoals Nitrate Plant" in _Chemical and Metallurgical Engineering_, January, 1919. CHAPTER III