February 27, 1913] 



NATURE 



69 = 



opened up by the discovery of new types of 

 penetrating radiation. 



(2) The work of Prof. H. A. Wilson is confined 

 to a discussion of the electrical properties of 

 incandescent bodies and of flames. Under the 

 influence of the ionisation theor_y of gfases this 

 important field of inquiry has rapidly developed, 

 and a large amount of experimental data has now 

 been accumulated. An account is first given of 

 the character and conditions of the discharge of 

 negative and positive electricity from glowing 

 bodies, followed by a discussion of the conductivity 

 of flames under different conditions. It has been 

 clearly established that the rapid discharge of 

 electricity from hot bodies is due to the escape 

 of free electrons, and the author discusses the 

 result in the light of the theory developed partly 

 by himself and partly by Prof. O. W . Richardson. 

 This theory supposes that the free electrons in 

 a metal acquire sufficient velocity at high tempera- 

 tures to escape from the metal and to give rise to 

 the observed discharge of negative electricity. 



The earlier experiments certainly afforded strong 

 ground for this conclusion. Since the publication 

 of this book, however, experiments have been made 

 by Pring and Parker and others which throw 

 same doubt on the completeness of this explana- 

 tion. It has been show'n that carbon at very high 

 temperatures and in a thoro"<7hIy exhau«;ted soace 

 gives only a minute fraction of the current to 

 be expected from the application of the theory 

 to the earlier measurements at lower temperatures. 

 There seems to be little doubt that, at any rate 

 in the case of glowing carbon, the large electronic 

 currents initially observed were due not to the 

 escape of electrons in the carbon itself, but rather 

 to some interaction between the carbon and the 

 residual gases. The theory of the subject is at 

 present in a somewhat unsatisfactory state, and 

 it would appear that more complete experimental 

 data are required before any theory can be 

 adequately tested. 



Prof. Wilson gives a brief but concise account 

 of the important experiments on the subject, 

 followed in every case by a discussion of the 

 results in the light of the theories proposed. An 

 excellent description is given of the experiments 

 on flames with and without the additions of salt 

 vapours, and the results are interpreted in terms 

 of the ionisation theory. The author himself was 

 a pioneer in this field and laid the foundation 

 of the present theory on a firm basis of experiment. 



The book is in no sense popular, but is written 



for the advanced student or investigator who is 



already familiar with the fundamental facts of 



the electronic theory and the ionisation theory 



XO. 2261, VOL. 90] 



of gases. It will be found very useful by all 

 physicists as giving a concise and straightforward 

 account of the present state of our knowledge of 

 a very interesting but difficult field of investiga- 

 tion. E. R^ 



PHILOSOPHY AND PSYCHOLOGY. 

 (i) The Nature of Woman. By J. Lionel Tayler. 

 Pp. 186. (London: A. C. Fifield, 1912.) 

 Price 3^. 6d. net. 



(2) Tlic Fundamentals of Psychology. Bv B. 

 Dumvillc. Pp. ix + 382. (London: W. B. 

 Clive, 1912.) Price 45. 6d. 



(3) Evolution and the Need of Atonement. By 

 Stewart .\. McDowall. Pp. xvi+155. (Cam- 

 bridge: University Press, 1912.) Price35.net. 



(4) On the Consciousness of the Universal and 

 the Individual. By Dr. F. Aveling. Pp. x + 

 255. (London: Macmillan and Co., Ltd., 

 1912.) Price 55. net. 



(5) Science and the Human Mind. By W. C. D. 

 Whetham, F.R.S., and Catherine D. Whetham. 

 Pp. xi + 304. (London: Longmans, Green and 

 Co., 1912.) Price 55. net. 



(6) The Note-Books of Samuel Butler, Author of 

 " Ercivhon." Selections arranged and edited 

 by Henry F. Jones. Pp. xii + 438. (London : 

 .\. C. Fifield, 1912.) Price 6s. net. 



(7) Tlic Spiritual Interpretation of Nature. By 

 Dr. J. Y. Simpson. Pp. xv + 383. (London: 

 Hodder and Stoughton, 1912.) Price 6s. net. 



(8) Papers on Psycho-.4.nalysis. By Dr. E. Jones. 

 Pp. XV + 432. (London: Bailli^re, Tindall and 

 Cox, 1913.) Price 105. 6d. net. 



(9) Qu.estions of the Day in Philosophy and 

 Psychology. By Dr. H. L. Stewart. Pp. x-;- 

 284. (London : Edward Arnold, igi2.) Price 

 lo.'.-. 6rf. net. 



(i) A DESCRIPTION, historical and bio- 

 Jr\. logical, of the feminist movement. 

 The conclusions of the author, who is a London 

 University Extension lecturer on biology and 

 sociology, are : that w-oman, not being merely 

 a female man, but of different aptitudes, has her 

 own proper sphere and direction of development ; 

 that her speciality is motherhood — not merely the 

 physical fact, but also the ennobling influences 

 involved ; that the married woman should not 

 work in factories, &c. , but should be economically 

 dependent on the man, as he is domestically 

 dependent on her ; and that a standard marriage- 

 able wage should be secured to the male worker. 

 The book closes with a reprint of W. C. Roscoe's 

 article, "Woman," in The National Review for 

 October, 1858. In this pioneer essay, "every 



