October 7, 1922] 



NA TURE 



477 



in tie bar joints, cotter joints, and coupling boxes. 

 The following chapters deal in succession with other 

 engineering details, such as belt and rope pulleys, 

 chain drives including sprocket wheels, bearings of 

 various kinds, and details of shafting, cylinders, and 

 pistons. Finally, structural details involving the 

 usual angles, tees, and channels with the more elaborate 

 columns, girders, and roof truss joints in which t he- 

 sections are employed give the student a useful intro- 

 duction to this side of engineering practice. 



The book covers much ground in its 158 pages. It 

 is very clearly written, and the publishers' part, in so 

 far as concerns the type and diagrams, is quite perfect. 

 For the purpose of familiarising the budding engineer 

 with the elements of machines and structures the 

 author has produced a most excellent book. 



Juvenile Delinquency. By Henry Herbert Goddard. 



Pp. vi + 120. (London: Kegan Paul and Co., Ltd., 



n.d.) 3.?. 6d. net. 

 No student of modern life can fail to be perturbed by 

 the number of juveniles who come before the courts 

 yearly for offences covering a very wide range. That 

 our present system does not deal with them adequately 

 is obvious. 



Delinquent behaviour is fundamentally unsocial 

 behaviour, i.e. the child is obeying his own instincts 

 instead of modifying them according to the demands 

 of society. It becomes therefore necessary to ask 

 why a child behaves unsocially. These unsocially 

 behaved children fall into at least two groups, (a) those 

 who are mentally too unintelligent to understand social 

 behaviour; and (b) those known as psychopaths, who, 

 while having normal intelligence, have not normal 

 control. 



The author suggests that these children should be 

 cared for by some bureau organised by the State, which 

 should undertake research work, be able to diagnose 

 cases before the behaviour has become seriously wrong, 

 and also to control the lives of those who will never be 

 able to control them for themselves. He describes in 

 this connexion the Ohio Bureau of Juvenile Research 

 which, although only established in 1914, has yet 

 justified itself by its work. 



Outwitting our Nerves : A Primer of Psychotherapy. 



By Dr. Josephine A. Jackson and Helen M. Salisbury. 



Pp. viii + 403. (London: Kegan Paul and Co., 



Ltd., n.d.) 75. 6d. net. 

 The stream of books concerned with explanations 

 of modern psychologists in general, and of Freud in 

 particular, for people of little or no psychological 

 knowledge, still flows on. Many fail entirely in their 

 avowed object, being either too condensed to be in- 

 telligible, or too popular to be scientific. The effect of a 

 conversion to Freudian doctrines is, only too frequently, 

 of the nature of a wholly uncritical acceptance of much 

 that Freud would call problematical. It is therefore 

 a relief to turn to this book, which not only gives a 

 very fair and balanced account of the findings of 

 psvcho-analysis, but also keeps these findings in per- 

 spective, showing them in relation to the known laws 

 of biology and psychology; The whole book is char- 

 acterised by r a sense of humour foreign to many writers 

 on the subject, and by sanity of outlook. Written in 



NO. 2762, VOL. I IO] 



an easy and popular style it can be safely recommended 

 to the student of, or sufferer from, " nerves," and even 

 to the reader already cognisant with the literature of 

 psycho-analysis it will prove helpful and interesting. 



Imperial Institute: Monographs on Mineral Resources 

 with Special Reference to the British Empire : Silver 

 Ores. By Dr. H. B. Cronshaw. Pp. ix+152. 

 (London: John Murray, 192 1.) 6jr.net. 

 This addition to the useful Imperial Institute Mono- 

 graphs gives details and statistics of the sources of 

 silver throughout the world. In 1918 the British 

 Empire produced nearly one-fifth of the world's supply, 

 Canada being responsible for the larger part of this 

 amount. The United States headed the list of pro- 

 ducers during the war period, but has now been passed 

 again by Mexico. About two-thirds of the world's 

 silver comes from base metal ores, and much of the 

 remainder is obtained from ores worked primarily for 

 gold, so that silver is mainly a by-product of other 

 metallurgical operations. The extraction and uses of 

 silver are dealt with only r very briefly in this monograph, 

 and some information as to the metallurgical processes 

 employed in the most important mining regions would 

 have added to its value. This remark applies particu- 

 larly to the account of the rich and metallurgically in- 

 teresting Cobalt district of Ontario, which is responsible 

 for the greater part of the Canadian production. These 

 monographs provide much information in a handy 

 form. 



A Systematic Qualitative Chemical Analysis : A Theoreti- 

 cal and Practical Study of Analytical Reactions of the 

 more Common Ions of Inorganic Substances. By 

 Prof. G. W. Sears. Pp. vi+119. (New York: 

 J. Wiley and Sons, Inc. ; London : Chapman and 

 Hall, Ltd., 1922.) 8s. 6d. net. 

 The introductory part of the work under notice con- 

 tains a brief account of such matters as equilibrium, 

 ionisation, and solubility product. The section on the 

 detection and separation of the metals is in the form of 

 numbered experiments, and is much less clear and 

 useful than the usual arrangement in tables. The 

 explanations of the reactions, however, are very clearly 

 and fully described, and would be useful in supplement- 

 ing analysis tables. The section on acids relies on pre- 

 cipitation methods with a single sample, and all pre- 

 liminary tests are omitted. This seems to be a mistake, 

 as many acids are readily found by simple preliminary 

 methods. There appear to be no features which would 

 indicate any marked superiority of the book over 

 existing treatises. 



An Introduction to the Chemistry of Radio-Active Sub- 

 stances. By Dr. A. S. Russell. Pp. xi+173. 

 (London : J. Murray, 1922.) 6s. net. 

 There is at present a real need for a small but up-to- 

 date book on radioactivity, in which the subject is 

 dealt with from the chemical as well as the physical side. 

 Dr. Russell's book would seem to supply this need very 

 satisfactorily. It is not overburdened with detail, but 

 gives a balanced account of the subject, which will be 

 found very useful to students. A particularly good 

 feature is the inclusion of the chemical methods of 

 separation and analysis, which sometimes tend to get 

 lost in theoretical speculations. 



