June 3, 1922] 



NATURE 



709 



mere cliches. The introduction contains valuable ob- 

 servations on living species, an addition to the scanty 

 literature of this subject which has real interest. Dr. 

 Cushman here directs attention to the protective colora- 

 tion of a small crab which has reddish spots of the same 

 colour as Homotrema rubrum (Lamarck), the remainder 

 of its carapace and legs being of the same colour as 

 the dead coral with which both the crab and Homotrema 

 are associated. So far as we remember, this is the first 

 record of a rhizopod in such a connection. There is 

 also a short note on the colours of living Foraminifera, 

 but this adds little to our knowledge of the subject, 

 and we regret that Dr. Cushman, with the facilities at 

 his disposal, has not gone more deeply into this ques- 

 tion, especially as regards Homotrema, Globigerina 

 rtibra, and Truncatidina rosea. 



Space does not permit us to discuss many interesting 

 points raised by the author, but his observations are 

 always temperate and demanding attention. We can- 

 not, however, agree with his suggestion that Marsipella 

 cylindrica, Brady, is really a species of Haliphysema. 

 If we have any quarrel with Dr. Cushman it is but the 

 old feud between " lumpers " and " splitters." Dr. 

 Cushman has an enthusiasm for the creation of new 

 species and varieties for what in many cases appear 

 to be merely local variations, a practice which, in our 

 opinion, is to be deprecated as tending to increase an 

 already intolerable state of confusion. There is less 

 excuse for him than for most " splitters," as his know- 

 ledge of the literature of the order is phenomenal. In 

 this memoir, out of 144 species and varieties recorded 

 23 are described as new to science, and there are 9 

 others previously separated by the author. Con- 

 sideration being had to the existing literature of West 

 Indian Foraminifera, we cannot help regarding the 

 proportions as excessive. E. H.-A. 



A. E. 



Our Bookshelf. 



Organic Chemistry, or Chemistry of the Carbon Com- 

 pounds. By Victor von Richter. Edited by Prof. 

 R. Anschutz and Dr. R. Meerwein. Translated from 

 the eleventh German edition by Dr. E. E. Fournier 

 D'Albe. Vol. 2 : Chemistry of the Carbocyclic Com- 

 pounds. Pp. xvi + 760. (London : Kegan Paul, 

 Trench, Trubner and Co., Ltd., 1922.) 35^. net. 

 " Richter " is too well known to need description, 

 and the only matter requiring attention is the way 

 in which the translator has done his work. In the 

 first place, it must be pointed out that the German 

 edition on which the translation is based was published 

 so long as ten years ago, and the volume for review is, 

 therefore, relatively out of date. In the second place, a 

 much more serious fault is the surprisingly inexact way 

 in which the translation has been carried through. Even 

 I an elementary knowledge of chemistry and of technical 



I NO. 2744, VOL. 109] 



German would have prevented such translations as 

 " carbohydrate " for " Kohlenwasserstoff," and would 

 have allowed the German names " benzol," " anilin," 

 " hydrazin," " hydrokinone," " mono-sulpho-per-acid," 

 etc., to have been rendered into their English equiva- 

 lents. As examples of chemical errors may be men- 

 tioned the use oi ferric sulphate as a reducing agent, 

 MnKO as the formula of potassium permanganate, 

 etc. These are but a few of the elementary blunders 

 for which the translator is responsible, and as a result 

 the book will be found very confusing by students. 

 As a book of reference for those who already have a 

 good knowledge of organic chemistry it will certainly 

 be found very useful. 



The Chemistry of Combustion. By Dr. J. Newton 

 Friend. Pp. viii + iio. (London: Gurney and 

 Jackson, 1922.) 45. net. ^ 



The account given by Dr. Friend of the chemistry of 

 combustion, including flame, ignition temperatures, 

 and the propagation of flame in gaseous mixtures, is 

 clear and concise and should be of interest to students. 

 Most of the newer work, especially that of Dixon and 

 his students, is covered, and adequate references are 

 usually given. If one might venture a criticism of 

 many recent monographs, including that under review, 

 it would be that far too little attention is now paid 

 to the experimental methods. To young students a 

 study of the way in which practical difficulties have 

 been faced and overcome is of much greater value 

 than a bald abstract of the results finally won. One 

 misses here, for example, an adequate account of the 

 highly ingenious apparatus of Dixon for the measure- 

 ment of the velocities of detonation waves (is there 

 not a difference between " detonation " and " ex- 

 plosion " ?), and that of Petavel and of Pier for the 

 measurement of explosion pressures (there is not even 

 a reference to the latter). The collected numerical 

 data in the book are useful ; a more critical treatment 

 would perhaps have been possible only if the author 

 had been an expert. 



A Course of Instruction in Quantitative Chemical 



Analysis for Beginning Students : With Explanatory 



Notes, Questions, and Analytical Problems. By 



Prof. G. McP. Smith. Revised edition. Pp. x + 218. 



(New York : The Macmillan Co. ; London : Mac- 



millan and Co., Ltd., 1921.) 125. net. 



Prof. Smith's book is intended for students who have 



completed a year's work in elementary chemistry, 



including qualitative analysis, and are beginning the 



study of quantitative analysis. In England a certain 



amount of volumetric analysis is usually included in 



the first year's course at the university, so that some 



of the second half of this book could be used with 



intermediate students. The directions are usually 



arranged under the headings of " Method," in which 



a brief but fully adequate account of the process is 



given ; " Procedure for the Determination," in which 



all the needful practical details of manipulation are 



described, so that the work of the demonstrator may 



be reduced to a minimum ; and, finally, " Notes," in 



smaller type, which give the reasons for the procedure, 



equations, theoretical explanations (in which physical 



chemical conceptions are explained and used), and 



