6;o 



NA TURE 



[November i i, 1922 



The new system of practice, which forms the subject 

 of the last chapter, is obvious!)- chiefly concerned with 

 rapid (time-saving) work, with a view to the inclusion 

 of some crystallographical account of all new sub- 

 stances, as well as existing ones, in a comprehensive 

 catalogue, or to the identification of a crystallised 

 substance by the comparison of such rapidly acquired 

 data with that contained in such a compendium of 

 measured substances. Two-circle methods are used, 

 and the table of angles characteristic of a substance 

 consists of the theodolitic <£ azimuth and p altitude 

 values. It is suggested that " two, or at most three, 

 crystals be measured," that " the indices be determined 

 by a time-saving method," that " the mean observed 

 angles be published without any citation of limits," 

 and that " the practice of computing theoretical 

 angular values (apart from those involved in the 

 elements) be discontinued." This may satisfy Mr. 

 Barker, and may possibly be adequate for the particular 

 purpose which he has in view. But it is most sincerely 

 to be hoped that serious crystallographic research is 

 not to be so circumscribed, and that absolute accuracv 

 will be placed before time-saving. Otherwise we shall 

 rapidly' revert to former chaos. It has been, indeed. 

 only by the most accurate and laborious work, in 

 which time was regarded as subservient to the highest 

 accuracy, that the subject has been brought to its 

 present high position ; this alone has rendered possible 

 the wonderful confirmation, by the absolute measure- 

 ments now made by the Bragg X-ray spectrometric 

 method, of the work of the later crystallographers. 



Our Bookshelf. 



Magnetism and Electricity. By J. Paley Yorke. New- 

 edition, completely rewritten. Pp. viii + 248. 

 (London : E. Arnold and Co., 1922.) 5.?. net. 



Wkittkn in colloquial language, this book, which is 

 a first-year course on magnetism and electricity, will 

 appeal to many beginners besides the students in 

 technical institutions, for whom it is primarily intended. 

 " These students have one great quality : they are 

 out to learn and to understand, and as they are not 

 hampered by the immediate necessity of cramming 

 for any particular examination, are able to enjoy the 

 pleasures of understanding instead of suffering the 

 terrors of memorising. . . . Memory is useful for 

 examinees, but understanding is essential for engineers." 

 There is abundant evidence throughout these pages 

 that the author is familiar with the difficulties met 

 with by the beginner, and he is always careful to explain 

 the technical terms which are apt to be used freely by 

 text-book writers who have almost forgotten that 

 their jargon is not that of the man in the street. 

 Magnetism is first dealt with, and then the ideas of 

 static and current electricity are introduced. The 

 author is particularly successful in developing the 

 self-contained water circuit analogy, the basic idea 



NO. 2767, VOL I 10] 



of which is that energy can be distributed without any 

 consumption of the water. Experience has convinced 

 him that the plan of introducing the measurement of 

 electrical energy at an early stage is very effective. 

 The basic ideas of electro-magnetic induction are 

 discussed in some detail, and in the final chapters the 

 phenomena of electrostatics are briefly treated. We 

 can recommend the book to those for whom it is 

 intended, but fear to think what the modern relativist 

 would have to say to such statements as, " Anything 

 which has weight is called Matter : magnetism is 

 therefore not matter " (page 21) ; " This something 

 which is called energy has not got weight " (page 57) ! 



The Climates of the Continents. By W. G. Kendrew. 



Pp. xvi + 387. (Oxford: Clarendon Press, 1922.) 



215. net. 

 Mr. Kendrew strikes new ground by giving a descrip- 

 tion of the actual climates of the regions of the world. 

 The scope of the treatment must naturally vary with 

 the nature of the original sources which are available, 

 but no detailed local descriptions are attempted. A 

 general knowledge of meteorology is assumed. There 

 is no explanation of the omission of polar climates, 

 north and south. Quite enough is now known of these 

 climates to enable useful accounts to be included in a 

 book of this sort. The oversight mars the usefulness 

 of the volume. We notice that Mr. Kendrew adheres 

 to the idea that the heating of north-west India 

 furnishes an explanation of the south-west monsoon. 

 The comparatively poor rainfall in the north-west he 

 attributes to the previous course of the winds reaching 

 that region, which has deprived them of much of their 

 moisture. According to Dr. G. C. Simpson, the 

 explanation is far more complex, and depends on 

 several factors, of which one of importance is the dry 

 upper-air current from the west, which prevents cloud 

 formation in the ascending air. These and other recent 

 theories regarding the monsoon are not discussed by 

 .Mr. Kendrew. There are many clear diagrams and 

 maps, and numerous meteorological data. All students 

 of geography wall be grateful for this well-arranged and 

 lucidly written volume. 



Miracles and the New Psychology : A Study in the 



Healing Miracles of the New Testament. By E. R. 



Micklem. Pp. 143. (London : Oxford University 



Press, 1922.) 75. 6d. net. 

 This work is concerned with a comparison between 

 the healing miracles described in the New Testament 

 and the case records of modern psychotherapy chiefly 

 drawn from war practice. A brief description of modern 

 psychotherapeutic measures is given, but the com- 

 plexity and difficulty of the subject almost necessarily 

 makes such a sketch confusing to the uninitiated 

 reader. The sources of the New Testament narratives 

 are examined and the inexactitude of observation is 

 commented upon, especially in the fourth gospel. The 

 current superstitions anent the relationship of sin and 

 disease and demonology are noticed as likely to colour 

 and detract still further from the trustworthiness of the 

 descriptions. 



The miracles are then dealt with seriatim, and where 

 possible, recent parallel cases are quoted. Finally, the 

 author disclaims the belief that all the subjects of the 



