The Department of Agriculture or your congressman will send you literature on the production and use of fertilizers. From your state agricultural experiment station you can procure information as to local needs and products. Consult the articles on potash salts and phosphate rock in the latest volume of "Mineral Resources of the United States," Part II Non-Metals (published free by the U.S. Geological Survey). Also consult the latest Yearbook of the Department of Agriculture. For self-instruction, problems and experiments get "Extension Course in Soils," Bulletin No. 355, U.S. Dept. of Agric. A list of all government publications on "Soil and Fertilizers" is sent free by Superintendent of Documents, Washington. The _Journal of Industrial and Engineering Chemistry_ for July, 1917, publishes an article by W.C. Ebaugh on "Potash and a World Emergency," and various articles on American sources of potash appeared in the same _Journal_ October, 1918, and February, 1918. Bulletin 102, Part 2, of the United States National Museum contains an interpretation of the fertilizer situation in 1917 by J.E. Poque. On new potash deposits in Alsace and elsewhere see _Scientific American Supplement_, September 14, 1918. CHAPTER IV Send ten cents to the Department of Commerce, Washington, for "Dyestuffs for American Textile and Other Industries," by Thomas H. Norton, Special Agents' Series, No. 96. A more technical bulletin by the same author is "Artificial Dyestuffs Used in the United States," Special Agents' Series, No. 121, thirty cents. "Dyestuff Situation in U.S.," Special Agents' Series, No. 111, five cents. "Coal-Tar Products," by H.G. Porter, Technical Paper 89, Bureau of Mines, Department of the Interior, five cents. "Wealth in Waste," by Waldemar Kaempfert, _McClure's_, April, 1917. "The Evolution of Artificial Dyestuffs," by Thomas H. Norton, _Scientific American_, July 21, 1917. "Germany's Commercial Preparedness for Peace," by James Armstrong, _Scientific American_, January 29, 1916. "The Conquest of Commerce" and "American Made," by Edwin E. Slosson in _The Independent_ of September 6 and October 11, 1915. The H. Koppers Company, Pittsburgh, give out an illustrated pamphlet on their "By-Product Coke and Gas Ovens." The addresses delivered during the war on "The Aniline Color, Dyestuff and Chemical Conditions," by I.F. Stone, president of the National Aniline and Chemical Company, have been collected in a volume by the author. For "Dyestuffs as Medicinal Agents" by G. Heyl, see _Color Trade Journal_, vol. 4, p. 73, 1919. "The Chemistry of Synthetic Drugs" by Percy May, and "Color in Relation to Chemical Constitution" by E.R. Watson are published in Longmans' "Monographs on Industrial Chemistry." "Enemy Property in the United States" by A. Mitchell Palmer in _Saturday Evening Post_, July 19, 1919, tells of how Germany monopolized chemical industry. "The Carbonization of Coal" by V.B. Lewis (Van Nostrand, 1912).