S E W BOOKS
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Certain errors in the labeling of the graphs in the first edition have been corrected on pages SI- and S V I I . S. C. LIND.
Orgunic Analutical Reagents. Vol. I I I . By FRASKJ. WELCHER.593 pp. Kew Tork: D. I-an Kostrand, Co., Inc., 1947. Price: $8.00 (series price, $7.00). The main purpose of this comprehensive work has already been stated in the reviex of the first volume (J. Phys. Colloid Chem. 51, 1035 (1947)). The present volume is of particular interest to all analytical chemists because it gives all the applications of such important reagents as dipyridyl and its derivatives, diouimes, monoosimes, nitroso compounds, (including cupferrnn) carbazides, and diphenylthiocarbazone. The book is divided into three parts. Part I (157 pages) deals with heterocyclic nitrogen compounds and contains five chapters; P a r t I1 (258 pages) deals with the oximes (nine chapters); and P a r t I11 (164 pages) discusses acidic imino compounds (five chapters). The literature is covered almost completely and few omissions have been found. The use of pyridine in the Karl Fischer reagent for the determination of water might have been mentioned. A list of oxidation potentials of the ferrous-ferric iron complexes of dipyridyl and derivatives should have been included, and also their use as indicators certainly deserves a special section. Analytical chemists are indebted t o the author and his coworkers for making this important reference book available. The author also deserves praise for the rapid appearance of the successive volumes. I. M. KOLTHOFF. Monograph on t h e Progress u j Research i n Holland During the War. Technological and Physical Investigations on L\7utural and Synthetic Rubbers. By A . J. WILSCHUT. 14.5 x 173 pp.; 72 fig.; 17 tables. S e w Tork: Elsevier Publishing Company, 20.5 cm. s i Inc., 1946. Price: $3.00. This monograph is one of a series on the progress of research in Holland during World War 11. P a r t I of the monograph deals with technological investigations and P a r t I1 with physical investigations on rubbers. I n Chapter 1 elastic high-polymeric substances are classified into “real” rubbers and rubber-like materials. The distinction is based on vulcanization, the former being vulcanizable and the latter non-vulcanizable. Compounding formulae for both pure gum and carbon black stocks are given and the mechanical, electrical, chemical, and physical properties, together v-ith aging d a t a of the stocks, are given and discussed. Chapter 2 includes measurements on the plasticity of unvulcanized rubbers, special aging tests, and a discussion of the mechanism of aging. This is followed by a niathematical interpretation of the stress-strain curve. Chapter 3 discusses vulcanization with non-sulfur vulcanizing agents. I n addition t o those known to the authors up to the year 1939, 2,4-toluylene diisocyanate is mentioned as being capable of vulcanizing rubber in benzene solution. The greater part of this chapter is devoted t o a discussion (Ivith data) of the vulcanization of rubber with synthetic resins, A discussion of 1-an der lleer’s theory of the vulcanization of rubber by phenolic resins, based on the formation of quinones as intermediates, is given. Chapter 4 of Part I1 is devoted to a resume of the iniportance of fundamental physical measurements in the determination of the structure of high polymers. Chapter 5 on “Plasticity and Elasticity” is somcwhat of a review and not entirely a report of investigations which \$ere carried out in the Setherlands during the war period, as indicated in the introduction. The calculation of degree of crystallization of rubber from therniodynamic d a t a . as is done on page 105, is open to question because the points for tension of the partly crystallized rubber are time dependent (see Bekkedahl: J . Research S a t l . Bur. Standards 13, 411 (1934)). Several hours may be required for equilibriuni t o be reached betn een the amor-
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