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NEW BOOKS
literature references are thoroughly covered and no doubt practically all have been seen in the original, as in previous volumes of the work. The mineralogy and geology of barium and the physical properties of the element and its compounds are fully dealt with and the literature includes the year 1932. The book is indispensable both to chemists and physicists and maintains the high standard of previous volumes, J. R. PARTINQTON.
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W. D. HACKH.viii Structure Svmbols of Organic Compounds. By INGO 139 pp. Philadelphia, P. Blakiston’s Son and Co. Price: $2.50. The author has devised an ingenious set of shorthand symbols for organic compounds, which he advocates as a substitute for-or rather, improvement on-the ordinary structural or graphic formulas using the chemical symbols of the elements and the usual connecting bonds. As a teaching device, the reviewer doubts very much if these symbols would have the value claimed for them, namely, that they make i t possible to include a larger amount of organic chemistry in the usual courses; and it would appear that the new symbols might have the definite disadvantage of getting the student even further away from reality than the usual structural formulas do, since in the new symbols no symbols for carbon, hydrogen, nitrogen, or oxygen appear’. But as a tool for advanced students and research workers, these new symbols appear highly advantageous, for they amount to a shorthand way of representing the structural formulas and can be written in much less time than even the most abbreviated structural formulas. This, i t seems to the reviewer, is the field in which these symbols have their greatest advantage, and this advantage is a considerable one. The first thirty-five pages of the book are given over to a discussion of the formulas, and then follow twenty-nine plates showing the formulas for about a thousand typical organic compounds. There is an index. LEE IRVIN SMITH. Einfuhrung i n die Tonphotographie. Photographische Grundlagen der LichttonAND R. SCHMIDT.23 x 15.5 cm.; vi 137 pp. Leipaufzeichnung. By J. EQGERT zig: S. Hireel, 1932. Price RM. 7. Card covers. The ear is far less tolerant in judging the reproduction of sound than the eye in judging the scale of intensities in a monochrome photograph. The difficulties encountered in reproducing sound free from distortion are therefore very considerable, and it is partly for this reason that so much experimental work has been carried out to investigate the photographic technique of sound recording. Few people could be found who are in better position to write an explanatory book on this difficult subject than Professor Eggert and Dr. Schmidt. They have been working in this field for some years and have now produced an excellent little book which should be welcomed by all interested in the general problems of photographic sensitometry as well a s by those engaged more narrowly in the actual problems of sound-recording. The book is well printed on good paper; there are one hundred and twenty-two very good illustrations, together with literature and general indexes. S. 0. RAWLING.
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Handbuch der Spectroscopie. Band VIII, Lieferung 1. By H. KAYSERand H. 654 pp. Leipzig: S. Hirzel, 1932. Price RM.67.50. KONEN. 26 x 18 cm.; i v It is now thirty-two years since the first volume of Kayser’s Handbuch was published, and it is interesting to read today in the preface t o that volume the scheme Professor Kayser had in mind for the complete work. The fourth volume was to
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