316 



SCIENCE 



[N. S. Vol. XXXIV. No. 871 



to others I suggest this. " Which is the worse, 

 the English of scientists or of politicians ? " 

 Will and shall barred. 



Arthur Gordon Webster 

 Worcester, Mass., 

 August 4, 1911 



SCIENTIFIC BOOKS 

 A History of the Theories of JEther and Elec- 

 tricity from the Age of Descartes to the 

 Close of the Nineteenth Century. By E. 

 T. Whittaker. London, Longmans, Green 

 & Co.; Dublin, Hodges, Figgis & Co., Ltd. 

 1910. Pp. xiv + 475. 



In this excellent volume, the Royal Astron- 

 omer of Ireland traces the development of our 

 ideas concerning the nature of the ether and 

 of electricity, as expressed by the various the- 

 ories which have been proposed from time to 

 time about these entities. 



The treatment includes an account of those 

 discoveries in light, electricity and magnetism 

 which have been influential in shaping and 

 supporting theory, and these facts are inter- 

 woven with the discussion of the theories 

 themselves in such a way that a historically 

 continuous narrative results. Everything is 

 made subservient, however, to the explanation 

 of the theories themselves. These are dis- 

 cussed at sufficient length to bring out their 

 chief features, and often too their limitations 

 are noted. The discussions are not confined 

 to verbal description, but preference is given 

 rather to a deeper treatment from the mathe- 

 matical side. The book is intended, therefore, 

 mainly for the advanced student who alone is 

 in a position to go into the details of the sub- 

 ject. 



The work opens with a chapter on the the- 

 ory of the ether in the seventeenth century, 

 covering a period in which the wave theory of 

 light had but begun to receive attention. The 

 next two chapters deal with the fundamental 

 discoveries in electrostatics and about steady 

 currents in conductors, and with the earlier 

 electrical theories. Then come two chapters 

 on the ether in that period when the wave 

 theory of light had its greatest development, 

 although light was still not associated with 

 electrical action. 



The following five chapters, beginning with 

 one on Faraday, cover a half century in which 

 attention was directed more and more upon 

 the action in the dielectric surrounding a con- 

 ductor, which finally resulted in the electro- 

 magnetic theory of light. The two closing 

 chapters deal chiefly with the rise of the the- 

 ory of electrons and the part they play in 

 optical and electrical phenomena. 



The book will be welcomed by all physicists 

 as a valuable contribution. J. Z. 



The Social Direction of Human Evolution: 

 An outline of the science of Eugenics. By 

 William E. Kellicott. New York, D. 

 Appleton & Company. 1911. 

 William Morris once said that a cause, in 

 winning its way to acceptance, had to pass 

 through three stages: first, all men ignored it; 

 second, all men opposed it; third, all men ac- 

 cepted it. The cause of eugenics has survived 

 the first stage without really entering upon 

 the second. It even seems possible that it 

 may contrive to skip a considerable part of 

 the second stage of the metamorphosis, and 

 enter into its heritage with little opposition. 

 It is much too early, however, to confidently 

 predict anything of the sort, and it may be 

 necessary to go through troublous times, if 

 only to arrest the attention of an easy-going 

 and unscientific public. 



Just now, the time is not ripe for an ex- 

 tended work on eugenics, but, on the other 

 hand, the moment is opportune for the ap- 

 pearance of a little book such as that of Pro- 

 fessor Kellicott. Wot long ago. Dr. C. B. 

 Davenport issued a very convenient little 

 pamphlet, which has been widely read. Pro- 

 fessor Kellicott's book is larger, but has a 

 similar aim, both being admittedly ephemeral 

 works intended to inform the general public. 

 Now that interest has been aroused in several 

 quarters, and important investigations bear- 

 ing upon the subject are being made, a new 

 book, or a new edition of an old one, will be 

 needed perhaps nearly every year for some 

 time to come. The volume before us will ex- 

 cellently serve present needs, and perhaps as 

 the necessity arises its author will prepare 



