acids. He treated the gas with a wide variety of substances known to have great affinity for oxygen and showed that the resultant compounds were not the oxides of the reagents employed. Although he did not prove that chlorine was an element he showed that it was not decomposable by any means which he could devise. He cautiously refrained from making any claims which his work was insufficient to support and named the gas chlorine because of its color. It is interesting t o note, also, that Davy produced the first carbon arc, although he did not attempt to make any practical use of it. Infact, the use of the carbon arc for lighting purposes would have been distinctly impractical in his day, for no economical or constant sources of current were available. The Davy safety lamp, in which the flame is protected from explosive external gases by means of a wire gauze, has been employed almost universally by miners. STUDENT CONTRIBUTIONS Is your chemistry club carrying on some worthwhile project? Have you, yourself, an interesting chemical hobby? Have you devised an original chemical experiment or piece of apparatus? Have you built a working model of a chemical plant or a piece of chemical machinery? Have you a chemical collection of any kind? Tell us and other students about it in an article of not more than one thousand words. If possible, illustrate your article with drawings or photographs, or both. I n preparing your manuscript, observe the directions to authors set forth on page 1534. Ten dollars will be awarded the high-school or undergraduate college student contributing the best item received on or before January 15, 1029. Five dollars will be paid for any other articles accepted for publication. Address your contribution to the Associate Editor, JOURNAL OF CHEMICAL EDUCATION, the Johns Hopkins University, Baltimore, Md.
Increased U. S. Tariff on Barium Carbonate. The cost, in the United States, of producing precipitated barium carbonate used in the manufacture of enamel wall paints and optical glass, exceeds the cost of production in Germany, the principal competing country, stated the United States Tariff Commission, in a report t o President Coolidge. Accordingly the president, upon the findings of the Commission, proclaimed a 50 per cent increase in the tariff. The Commission's report resulted from a cost of production investigation which it instituted upon applications from the Bertha Mineral Co., of Newark, N. J.; the Barium Reduction Co., of Charleston, W. Virginia; and the Chicago Copper and Chemical Co., of Blue Island, Illinois.-Chem. Age, 19, 289 (Sept. 29, 1928).
