142 



NATURE 



[April 25, 1918 



upon when he expounds scientific theory. It is a 

 little disconcerting, for example, to find (p. 5) 

 Dr. A. A. Robb's theory of time and space re- 

 ferred to as a form of the theory of relativity. 

 The misprint Rolls' for Rohh's is perhaps pardon- 

 able carelessness, but the account of Einstein's 

 principle of relativity is so slight and inadequate 

 as to be positively misleading-. 



(4) "Thomas Sharnol " describes his adven- 

 ture as "a popular study of the creative mind." 

 It deals with the problem which is the most deeply 

 interesting of all the problems of philosophy, yet 

 the impression the reader is likely to derive is one 

 of bewilderment in regard to the precise concept 

 of "originality " he is invited to study. The book 

 is an amazing pot-pourri of opinions, sentiments 

 grave and gay, quotations from, and references to, 

 writers of all .sorts, past and present. The main 

 philosophical motive which serves to hold the 

 attention amidst the author's exuberance is the 

 notion with which Bergson has familiarised us, 

 that life is an impetus finding expression in the new 

 forms it creates. Combined with this is the notion 

 of the structure of unconscious mind which we 

 owe to the discoveries of Freud and Jung. The 

 book is very uneven, sinking at times to sheer 

 triviality, yet pleasantly written and always good- 

 humoured. It is intentionally addressed to the 

 thoughtful man of general culture, and not to the 

 student of technical philosophical problems. 



H. W. C. 



PHYSICS TEXT-BOOKS. 



(i) A Text-hook of Physics for the Use of Students 

 of Science and Engineering. By J. Duncan and 

 S. G. Starling. Pp. xxiii+1081. (London: 

 Macmillan and Co., Ltd., 1918.) Price 155. net. 



(2) Advanced Text-book of Magnetism and Electri- 

 city. By R. W. Hutchinson. Vol. i.. Magnetism 

 and Electrostatics. Pp. vii + 372 + Index xii. 

 Vol. ii.. Electrodynamics. Pp. vi + 468+ Index 

 xii. (London: University Tutorial Press, Ltd., 

 1917.) Price, 2 vols., 85. 6d. 



(3) Lecture Notes on Light. By J. R. Eccles. Pp. 

 vi + 217. (Cambridge: At the University Press, 

 1917.) Price 125. 6d. net. 



(4) A Manual of Physics, Theoretical and Practi- 

 cal, for Medical Students. By H. C. H. Candy. 

 Second edition. Pp. viii + 451. (London : 

 Cassell and Co., Ltd., 1918,) Price 75. 6d. net. 



(i) T7NGINEERING students too often look 

 •*--/ upon physics as little more than a neces- 

 sary evil, and a book that connects the scientific 

 aspects of the subject with its modern practical 

 applications fills a real need. The authors of this 

 volume — one an engineer and the other a physicist 

 — are to be congratulated on the successful way in 

 which they have accomplished this task. 



The book, which is both theoretical and practi- 

 cal, gives a course in dynamics, sound, light, heat, 

 magnetism and electricity, which the authors claim 

 is suitable for intermediate examinations. A stu- 

 dent, however, who knew all in the book would be 

 NO. 2530, VOL. lOl] 



well beyond this stage. Few of the objectionable 

 features of examination text-books occur, and the 

 treatment is lucid and up-to-date. Modern high 

 vacuum pumps, internal-combustion engines, peri- 

 scopes, range-finders, kinemacolor, dynamos, 

 X-rays, and radio-activity, are all considered. 

 Strangely, there is no reference to wireless tele- 

 graphy, and some criticism might be offered of the 

 treatment of Newton's "Laws of Motion." Minor 

 details apart, however, the book is most satis- 

 factory and should make a strong appeal to all 

 engineering students. 



(2) This is a text-book for final degree exam- 

 inations, and it will probably appeal to the 

 student who has but little outside assistance. The 

 explanations are very full, and definitions and 

 statements of special importance are printed in 

 heavy type. There is a large collection of prob- 

 lems, taken chiefly from university examination 

 papers, and some of these have been fully worked 

 out. Brief directions for practical work are also 

 given in the text. 



The treatment mostly follows on stereotyj>ed 

 lines, but references to modern developments are 

 interspersed, and the chapters on radio-activity, the- 

 passage of electricity through gases, and elec- / 

 tionic theories are well written, and it is here diflfi- 

 cult to find any of the more important developments 

 of the subject that are left untouched. 



(3) This book was originally written for the 

 pupils of Gresham's School," Holt, and it probably 

 forms a satisfactory supplement to the author's 

 course of lessons; but it is nevertheless unlikely to 

 make any gfeneral appeal. 



The master is supposed to "lecture on the lines 

 of the notes and draw the diagrams on the board, ".• 

 whilst the boys enter the diagrams in special copies 

 of the book with blank left-hand pages. The pre- 

 sent volume is intended as a guide to the master, 

 and the diagrams — some very carefully drawn — 

 are inserted. The wording throughout is some- 

 what loose, but in spite of this the author wishes 

 his definitions to be "learnt by heart." On p. 117 

 the "edge of a prism " is defined ! Further, we are 

 told that, " since light travels in straight lines, any 

 one of these straight lines is called a ray of light." 

 The objection to the corpuscular theory is that, " if 

 the corpuscles travelled with this immense velo- 

 city, they would possess considerable momentum, 

 of which there is no evidence " ; whilst, after three 

 lines of explanation, the wave theory is dismissed 

 as "the one that is now in vogue." 



(4) Students working for the First Examina- 

 tion of the Conjoint Board, or even pos- 

 sibly for the London University First Medical, 

 will find in this book most of the information they 

 need. In addition to the ordinary theoretical 

 work, about forty pages of the book are devoted to 

 brief instructions for carrying out a number of 

 illustrative experiments. The style is simple 

 throughout, sometimes even at the expense of 

 accuracy, and descriptions of out-of-date pieces of 

 apparatus still occur. Nevertheless, those who 

 have never studied physics before will find the book 

 very useful. The present edition appears to be a 



