NEW BOOKS The Phenomena of Polymerisation and Condensation. A General Discussion held by the Faraday Society, September, 1935. 25 x 17 om.; vi 412 pp. London: Gurney & Jackson, 1936. Price: 22s. 6d. It may be said without question that this volume is one of the most interesting published by The Faraday Society during recent years. Polymerisation and condensation products are of great fundamental and technical interest and are now receiving due attention. Professor Rideal in his introductory paper distinguishes between three types of polymers: first there are the polymers formed by linear accretion; secondly, those in which a large ring is the structural unit; thirdly, there is the condensation product formed by cross-linkage. The discussion is divided into two parts, called “general” and “special”; each of these contains highly instructive papers. Particular attention should be drawn to the two papers by Staudinger, the first of which is an extremely lucid survey of the formation of polymers of unsaturated substances. Readers coming to the subject freshly would do well to study this paper immediately after Rideal’s, in order to gain some idea of the types of product and the relative ease of polymerisation in the various cases. It is impossible to review individually all of the numerous contributions, but mention may be made of a few of special interest. Already attempts are being made to study the structure of polymers by means of x-rays; the difficulty is of course that most of them are “amorphous”. Kat2 however shows that interesting deductions may be made by comparing the patterns with those of monomeric substances of similar type. Houwink and de Boer are making valiant theoretical attempts to link up the physical properties of polymers with atomic linkage forces, and their papers deserve close attention. Meyer has studied polymerised sulfur and poly-phosphonitrilic chloride by means of their x-ray diffraction patterns, and Melville and Gray give evidence t o show that the vapor of red phosphorus is not polymerised but consists of PJ molecules. The well-known American authorities on hydrous oxides, Weiser and Milligan, conclude that many of these are not polymerised but simply aggregates of microcrystalline particles with strong adsorptive properties. An interesting and promising application of physical methods to organic polymerisation described by Farquharsoa consists in following the change of magnetic susceptibility during the process. For reference purposes the usefulness of these volumes would be improved very greatly by the addition of a subject index; the volume will no doubt serve the purpose of a handbook to many and the price is such that full documentation may be reasonably expected. The work of the editorial committee would be minimized in this respect if each author supplied a brief list of the important points dealt with in his paper. J. T. RANDALL.
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Fhorescenee Analysis i n Ultra-violet Light. By J. A. RADLEYand JULIUS GRANT. 5+ x 8% in.; xi 308 pp. 2nd edition. New York: D. Van Nostrand Go. This second edition, appearing only three years after the publication of the first edition, signifies the interest in fluorescence analysis as also does the faat that over three hundred papers have appeared in this three-year period. The authors pointed 855
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