DISCOVERY 



277 



tion of the rare earths, to do with the subject ? For the 

 best books, even the best textbooks, are written when the 

 author wTites what he knows about and from his own 

 angle, and withstands the desire to say a few words on 

 everything theoretically embraced by his subject. Mr. 

 E\ans has done a great work in producing this useful 

 work single-handed, but a critic mu.st affirm that he need 

 not ha\-e taken four \-olumes to say his say. 



Atomic Structure and Spectral Lines. By Arnold 



SoMMERFELD. Translated from the third German 



edition by Henry L. Brose, M.A. (Methuen & Co., 



Ltd., ij^s.) 



This work of the professor of theoretical physics at 



Munich is the standard book on atomic structure in use 



on the Continent, and contains an accurate and singularly 



luminous account of the subject up to the year 1922. 



It is for the advanced student only ; indeed, " quite a 



lot of algebra " is necessary for its finer points to be 



understood. All students of physics and of physical 



chemistry are indebted to the translator and to the 



publisher for this book in its English dress. Its place is 



already with the great monographs on Physics which in 



our day include Rutherford's Radio-active Substances, 



the Braggs' X-ravs and Crystal Structure, Bolir's Theory 



of Spectra and Atomic Constitution, and Aston's Isotopes. 



Stories of Scientific Discoveries. By D. B. H.\mmoxd. 

 (Cambridge University Press, 65.) 



Mrs. Hammond gi\'es in this excellent book short 

 accounts of ten scientists of the front rank and their 

 work. The book has been carefully compiled from the 

 original biographies and is most interestingly written. 

 It is pleasant to have an account of scientific workers 

 which is not marred by untempered enthusiasm, or by 

 the irrelevancies and inaccuracies of the hack writer. 

 The book, in addition, is beautifully printed and the 

 illustrations are good. The authoress has chosen her 

 subjects from different branches of natural science, and 

 selected those lives which are interesting both on the 

 human and on the scientific side. The subjects chosen 

 are Priestley, Lavoisier, and the chemical revolution ; 

 Count Runiford ; Herschel and the discovery of the 

 planet Uranus ; Jean Fabre ; Faraday and liis electrical 

 discoveries ; the Curies and the discovery of radium ; 

 Darwin, Wallace, and the theory of evolution ; and 

 finally Pasteur and his work on germs and inoculation. 

 The book is heartily recommended to our readers. 



Light and Colour. By R. A. HousToux, M.A., D.Sc. 

 (Longmans, Green & Co., 7s. 6d.) 



This book deals in a popular manner with those aspects 

 of light and colour which the author, a distinguished 

 worker in the subject of Optics, has found to appeal most 

 to the man in the street. It contains chapters on the 

 spectrum, the nature of Ught, invisible rays, the structure 

 of atoms and of stars, the primary colours, colour- 

 blindness, colour photography, the light of the future, 

 photochemistry, phototherapy, and the psychology of 

 colour. I do not know anv book of a popular or a semi- 



popular kind, published since Sylvanus Thompson's 

 Light Visible and Invisible, that covers the ground so 

 thoroughly or that will so well meet the needs of those 

 interested in light as this one. 



Dr. Houstoun has an advantage o\'er manv writers of 

 books of knowing his subject inside and outside, up and 

 down, and he has succeeded in writing not only accurately 

 and with interest, but with a good deal of humour. And 

 though he is evidently very familiar with the literature 

 of the past, from which he makes several pertinent quota- 

 tions, his standpoint is, of course, the modern one. He 

 has not much to say for journalists who " explain 

 Einstein." He thinks the soundest attitude with regard 

 to that scientist's theory is to " wait and see." " While 

 Einstein's formulae are mathematically accurate, it is no 

 disparagement of his great work to suggest that he has 

 not correctly interpreted them. Christopher Columbus 

 died under the impression that it was a new route to the 

 East Indies he had discovered, not America." . . . "Some 

 of the authors who wish to upset Fresnel's work in order 

 to explain the new deflection . . . have about as much 

 sense of proportion as the man who would burn down 

 the house to boil his tea-kettle." 



The chapters on colour-blindness, on the light of the 

 future, and on the psychology of colour will be found 

 most interesting by the general reader. 



The Discovery of the Nature of Air and of its Changes 

 during Breathing. By Cl.a.r.\ M. Taylor, M.A. (G. 

 Bell & Sons, is. 6d.) 



This is the second of the Classics of Scientific Method, 

 of which Dr. Singer's The Circulation of the Blood was 

 the first. We may apply to the second what was said of 

 the first, " authentic, well wTitten and well produced," 

 and add " wonderful value for the money." This one, 

 by the Head Mistress of the Northampton School for 

 Girls, contains a history of the knowledge of respiration 

 from the time of Harvey (1578-1667) to the time of 

 Lavoisier (i 743-1 794), and contains a description of the 

 views and experiments of these men and of van Helmont, 

 Robert Boyle, Lower, Mayow, Hales, Stahl, Joseph 

 Black, and Priestley. It is suitably illustrated. This 

 book is heartily recommended to all readers interested in 

 the history of science. 



The Structure of the Atom. By E. N. D.\ CosT.\ Andr.-\de, 

 D.Sc, Ph.D. (G. Bell & Sons, 165.) 



Dr. Andradfc was in Sir Ernest Rutherford's laboratory 

 in Manchester in the years before the war, and was 

 consequently in touch with the w-orkers whose experiments 

 and ideas led to the theory of the structure of the atona 

 now widely accepted. He has done advanced students 

 of physics a service in selecting the important facts and 

 theories, and in setting them forth in a clear and accurate 

 manner that shows throughout independent thinking 

 and judgment. This book and Sommerfeld's transla- 

 tion noticed above are at present the only all-embracing 

 works on this subject in English. Dr. Andrade's book is 

 more suitable for a first reading of the subject, for it does 

 not treat details in so extended a manner as Sommerfeld, 



