May 27, 1922] 



NATURE 



^11 



international waste, and any system which is concerned 

 primarily with alleviating the suffering entailed rather 

 than removing its cause must be inadequate. By 

 proper planning of work so as to meet seasonal fluctua- 

 tions, by a wiser use of the competitive system and 

 certain methods of standardisation, much can be done 

 to remove a social evil which is probably doing more 

 to destroy the vital energy of the industrial population 

 than any other one cause. 



The book contains a great deal of carefully arranged 

 statistical matter which provides useful data for 

 those wishing to study certain problems independently. 

 Many of the recommendations made are naturally 

 more applicable to American conditions than to 

 British^ and it is to be hoped one outcome of the 

 publication of this book will be that a similar inquiry 

 will be undertaken in this countrv. 



Our Bookshelf. 



A Text-Book of Inorganic Chemistry. By Prof. A. F. 

 Holleman. Issued in English in co-operation with 

 H. C. Cooper. Sixth English edition, revised. Pp. 

 viii + 528 -t- 1 plate. (New York : J. Wiley and Sons, 

 Inc. ; London : Chapman and Hall, Ltd., 1921.) 

 195. net. 



Prof. Holleman's text-book is well known as one of 

 the best introductory treatises on the subject, and, it is 

 only necessary to point out that the new edition has 

 been revised and brought up to date. In this operation 

 a few minor inaccuracies have escaped notice. Thus, 

 on p. 133 it is stated that of the nine oxy-acids of 

 sulphur (one is omitted), only sulphuric acid has been 

 obtained in a pure state, whereas on p. 146 the two 

 persulphuric acids are described as crv'stallising in the 

 pure state. The descriptions of preparations are some- 

 times so condensed as to be almost inaccurate, e.g. 

 (p. 54) hydrogen peroxide " in a very concentrated 

 state can be obtained by direct distillation in vacuo of 

 a mixture of sodium peroxide and sulphuric acid," and 

 on p. 69, in connection with the preparation of hydro- 

 bromic acid, the usual method is scarcely adequately 

 described as " the decomposition of a bromine com- 

 pound with a hydrogen compound, phosphorus penta- 

 bromide and water being employed." The statement 

 (p. 29) that " the atomic weights of most elements are 

 determined from the composition of their oxygen com- 

 pounds," although common, is quite incorrect, and 

 should be compared with the true state of affairs, given 

 on p. 306. 



Typical Flies : A Photographic Atlas. By E. K, 

 Pearce. Second series. Pp. xiv-f-38. (Cambridge: 

 At the University Press, 1921.) 155. net. 



The atlas of photographic illustrations of typical 

 British Diptera under notice is supplementary to the 

 one published by the author in 1915. It consists of a 

 series of well-executed half-tone figures arranged on 

 36 pages. The difficulties experienced in photograph- 

 ing such objects as flies really effectually are consider- 



able. In photographing on the enlarged scale required, 

 no amount of " stopping down " will produce an image 

 sharp all over, since all the parts of an insect do not lie 

 in the same plane. Many of the figures are excellent 

 examples of what can be executed by this method. On 

 the other hand, those of the larvae and pupae are not 

 very successful : Fig, 16 of the larvae of Coretha, for 

 example, is far inferior to a good line drawing. It is 

 difficult, however, to understand why some of the 

 specimens used for illustration were not better chosen. 

 Why, for example, figure a Trypetid fly the abdomen of 

 which is so distorted as to appear to be missing ; or, in 

 other cases, utilise specimens in which the legs have 

 never been displayed in the process of setting. We 

 gather the object of this work is to stimulate the study 

 of this neglected but highly important order of insects 

 and, by means of suitable illustrations, to guide the 

 beginner in relegating his specimens to their respective 

 families. In the latter respect this atlas will probably 

 prove of distinct service. 



The Yearbook of the Universities of the Empire, 1922. 



Edited by W. H. Dawson and published for the 



Universities Bureau of the British Empire. Pp. 



' XV -I- 653. (London : G. Bell and Sons, Ltd., 1922.) 



75. 6d. net. 



The changes which have been made in this valuable 

 handbook since last year's issue was published are 

 due mainly to an increase in scope and therefore in 

 size. Nearly two hundred pages of useful information 

 have been added, in spite of the fact that the price has 

 been reduced to one-half. Brief accounts are given 

 of the universities, together with lists of their staffs, 

 of England, Wales, Scotland, and Ireland, followed 

 by similar statements for the universities of Canada, 

 Australia, New Zealand, South Africa, India, Malta, 

 and Hong-Kong, in the order given. The appendices, 

 which formed a valuable feature of previous editions, 

 have been extended, so that now most of the learned 

 and professional institutions are dealt with. There are 

 also brief notes on continental universities and uni- 

 versities in the United States of America, as well as 

 information on the subjects of inter-university scholar- 

 ships and grants for research both at home and abroad. 

 The text is reduced to a minimum, but the essential 

 facts are given, and it is difficult to find any other 

 single volume which will serve so effectively as a refer- 

 ence book on institutions for higher education in 

 the British Empire. 



Memoires sur V Electroniagnetisme et V Electrodynamiqne. 

 Par Andre-Marie Ampere, (Les Maitres de la 

 Pens^e Scientifique : Collection de Memoires et 

 Ouvrages. Publiee par les soins de Maurice Solo- 

 vine.) Pp. xiv+iii. (Paris: Gauthier-Villars et 

 Cie, 192 1.) 3 francs net. 



The two memoirs given in this volume have been 

 taken from Ampere's wonderful " Recueil d'observa- 

 tions electrodynamiques," published in 1822. CErsted 

 had described a few years previously the action of an 

 electric current on a compass needle, and in the first 

 memoir under notice, the mutual action of two electric 

 currents on one another is described. The author 

 then describes the apparatus he made and the 



NO. 2743, VOL. 109] 



