Silica Refractories SIR: Since the article on “Silica Refractories“ [Herdle, -4.J., and Wolthorn, H. J., ASAL. CHEJI.,21,705 (1949)l was published it has come to our attention that when varying amounts of the
Table I.
calcium oxide are present as such, high results will be obtained by the method as described. In most cases, this has been overcome by using the follorving excitation conditions: Capacitance. mfd. Prespark period, sec. Exposure period, see. Filter
Supplementary Determinations
Per Cent Calcinm Oxide Chemical Original method method 2.49 2.63 2.39 2.29 2.14 2.31 2.40 2.67 2.09 1.99 2.50 2.71 2.24 2.24 1.68 1.80 9 1.73 1.80 2.18 10 4.18 Average deviation (excluding 10) 0.13 NO. 1 2 3 4 5 6 7 8
Revised method 2.31 2.42 2.14 2.46 2.04 2.47 2.12 1.69 1.83 2.85 0 06
60 10
20 Screen
Other parameters are the same as for the original method. This modification is less reproducible than the original, so that determinations are made in triplicate. Table I compares results obtained by the two methods with those obtained by a chemical method. Calibration curves mere Iiased on the same standards.
A. J. HERDLE H. J. WOLTHORX Cainegie-Illinois Steel Corporation I’oungctown 9, Ohio
Electronic Interpretations of Organic Chemistry. .4. Edward Remick. 2nd edition. vii 600 pages. John Kiley 8: Sons, Inc., 440 Fourth .4ve., New Tork, X. Y., 1949. Price, $6.00.
could have been formed only by disproportionation of free radicals.” I t is difficult to consider seriously that Hantzsch’s results on the acidification of the sodium salt of nitroethane find an “evident interpretation” ;i the assumption that the folloa ~ n g proress i- a qloi~one (page 241):
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The second edition of this well-knoivn book has been awaited with interest by all those concerned with electronic interpretations of organic chemistry. There are many good features in this book, especially in the sections on contributions from chemical physics and in the new chapter on stereochemistry. This reviewer strongly feels, however, that a rather confusing picture would be considerably clarified if the author abandoned the attempt to folloiv the English school terminology with its large number of special effects. Inasmuch as the theory is only roughly qualitative, albeit extremely serviceable, it seems rather pointless to devote much time to terminology of Is, Id, +E - E type, to say nothing of proposals (page 62) that “heteroelectromeric” and “homoelectronieric” might be useful additions to the list. The uninitiated niay \vel1 be bewildered by the fact that although it is clearly stated on page 58 that mesomerism is not to be thought of as a kind of tautomerism, the author quotes 011 page 79 an interpretation of 1,4 addition through an ion “which may tautomerize.” Some interpretations given of well-kno~vnorganic reactions are misleading-for instance, the discussion of the Diels-Alder reaction (page 447) in IThich it is stated that pyridine and quinoline have been successfully substituted for alkadienes; that there is no kno\vn catalyst for the reaction (disregarding the work of \Vassrrman); that the reaction of maleic anhydride with unconjugated olefins involves primary dissociation of the diene to form a carbanion (no evidence whatever). Furthermore, steric factors which provide a ready interpretation of, for instance, the diallyl case (page 449) are ignored. There may well be some evidence that free radicals are involved in the Grignard reaction, but it is hard to accept the statement (page 501) that the “reaction products [ethane and ethylene]
,03
CH 2CH=K ‘0
-
e
0
CH~-CH--S/
NO
rl number of topics n-hich are absent from the book could h a r e been profitably included-although there is a discussion of Raman qpectra, nothing is said of infrared spectra. We might further nish that in a book on electronic interpretation there would be some discussion of a number of reactions of considerable intereqt, w c h as Wagner-Meernein, benzilic, Bechmann, or Clai-en I carrangements. The last-mentioned rearrangement is, it is true, considered on page 509, but is immediately dismissed n ith the statement that there can “no longer be much doubt as to Ilts] mechanism,” implied to be free radical in type. GILBERTSTORK Chemie fur Bauingenieure und Architekten. Richard G/,tcn. viii 212 pages. Springer Verlag, 1 Jebensstrasse, Charlottenburg 2, Berlin, Germany, 1949. Price (paper), 16.50 marks.
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This book deals with the chemistry of most structdral niateyials. I t should be of interest to all who would like to know about the chemical properties of concrete, steel, wood, cements, aqphalt, and plastics, to name a few of the materials described. The subject matter is described in an interesting manner but suffers from both superficiality and inaccuracy. All metals other than steel are discussed in three pages, paint and protective coatings in one. Xhile the chemistry in the test is mainly de622
