98
JOURNAL OF CHEMICAL EDUCATION
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JANUARY,
1932
AND HENDERSON, "A C o m e in General Chemistry, 3rd edition, (2) MCPHERSON Ginn & Co., New York City, 1927, 702 pp., p. vi. (3) KENDALL,"General Chemistry," The Century Co., New York City, 1927, 676, p. viii. "Smith's College Chemistry," The Century Co., New York City, (4) KENDALL, 1929, 759 pp., p. v. (5) KENDALL,"Smith's College Chemistry," ref. (4). p. 268. KENDALL, "Smith's Introductory College Chemistry," The Century Co., New York City, 1931, 555 pp.. p. 226. (6) SLATER,"Directed Valence in Polyatomic Molecules," Phys. Rm.,37, 481-9 (Mar. 1, 1931); "Annual Reports of the Progress of Chemistry for 1930," The Chemical Society, London, 1931, p. 15. (7) Science (Sup.). 73, 14 (June 26. 1931). (8) Encyclopedia Britannica, fourteenth edition, Encyclopedia Rritannica. Inc.. New York City, 1929, Vol. 23, p. 850. (9) "Annual Survey of American Chemistry," The Chemical Catalog Co., New York Citv. .. 1930. Vol. V...n. 10:. "Annual Renorts of the Promess of Chemistrv for 1930," ref. (6), p. 289. (10) . . HALL.N. F.. "Modern Canceotions of Acids and Bases." . 1. CEEM.EDUC.. . 7., 782-93 (April, 1930); WALDEN."Salts. Acids, and Bases," McGraw-Hill Book , Conductivity of Solutions." Co., New York City, 1929, 391 pp.; D a v r ~ s "The John Wiley & Sons, Inc., New York City, 1930, 204 pp.; LEWIS, "Valence and the Structure of Atoms and Molecules." The Chemical Catalog Ca.. New York City, 1923, 172 pp. (11) GERMANN, J. Am. Chem. Sac., 47, 2461 (1925). (12) LEWIS, lac. cit., p. 142. (13) DAVIES,106. dl., P. 156. (14) See HALL,loc. cit., p. 787. C (15) WALDEN, 106. cit., p. 158. (16) WALDEN,bc. cit.. p. 159. (17) See WALDBN, 106. cil., p. 96. (18) See WALDEN,106. tit., p. 159. (19) HALL,IOC. tit.. p. 788.
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Radium 5 d s a ~ ~ l i c s t i oinn inspectinn steel welds. Radium's gamma rays have found another use. D'; Gilbert E. ~ o i of n Lehigh University reportedto the ~ k e r i c a n Society for Steel Treating recently. They make rapid and sure testing of steel welds possible. While ordinary testing of electrically made joints in steel necessitates breaking the joints, according to Dr. Doan, gamma-ray photographs of the joints disclose defects inherent in the welding without fracturing them. Previous use of X-ray and gamma-ray photographs of steel castings gave Dr. Doan the idea, he said, of using radium to reveal the flaws of welds. Dr. Doan's experiments showed that his method is adequately sensitive and definite. Under the previous proeess, photographs of the fractures of the welds were insufficient because the coloring as well as the outlines of the fractures was necessary to show if defects had existed. But simple inspection of the gamma-ray photographs hy one who can interpret them, according to Dr. Doan, reveals all that is needed to know about Service the steel joints.-Sku
