486 



NA TURE 



[March 23, 1905 



inodeni militarism — is as interesting as it is pardon- 

 able. 



The following are some of the main characteristics 

 of the author's point of view : — (i) While defending 

 metaphysics from the charge of being " built upon 

 air or quicksands," he readily admits that it has not 

 always taken full advantage of the science which it 

 knows, and that greater accuracy of scientific detail 

 ought to be displayed if it is to appeal to the " plain 

 man " with some knowledge of physics, chemistry, 

 and biology. In the same spirit the chapters on God 

 and the Absolute and Human Immortality attempt 

 to do something like justice to the religious aspira- 

 tions of the "plain man," which are so severely 

 neglected in such a work as " Appearance and 

 Reality." (2) Mr. Arnold prefers activity to existence 

 as a basis for investigation. The lower animals, in 

 his view, display only " teleological activities"; the 

 entity " mind " (self-conscious and introspective) 

 belongs only to men. And perhaps not even to all 

 men : " a human being might theoretically pass 

 through life and never be actual mind; possibly with 

 some savages this is almost the truth." (3) Again, 

 Mr. .Arnold is fond of the contrast between the in- 

 dividuation (real and objective in every sense) by 

 means of the atom or the electron — " the true physical 

 entities " — and the individuation by means of colour, 

 sound, and the like which depends on our " particular 

 sensuous evolution." The latter form of individu- 

 ation, which finds expression particularly in the 

 " material totalised image," seems therefore to show 

 that in mind (including " teleological activity ") there 

 is something new in principle. " But by asking 

 whether it is a new entity we merely confuse matters. 

 For we should thus assume that the physical world 

 is once and for all limited to atomic activities, whereas 

 all observations tend to show that the various entities 

 are continually changing and re-organising them- 

 selves, and developing new relations and qualities." 

 In one sense Mr. Arnold claims that his view of mind 

 in the non-introspective animal is as materialistic as 

 it could be, since mind under such conditions " is 

 matter totalised in a special manner in relation to an 

 external crisis." But he hastens to add that " pre- 

 mental matter was not merely the matter of physics 

 and chemistry." And mind in man he certainly re- 

 gards as something very different. 



It is impossible to do justice to this suggestive work 

 in a short notice, and we are well aware that the 

 above is only a hasty and somewhat arbitrary selec- 

 tion of a few of the topics treated. The views of 

 matter and ether, in particular, might well have a 

 notice of their own ; so might the chapter on psycho- 

 physical interaction, which is almost a model of philo- 

 sophical discussion. In this last the theory is stated 

 that the initial impulse required to liberate the energy 

 of the muscular system comes ultimately from " ex- 

 ternal sources," e.g. when the sight of some object 

 moves us to pursue it, from the ethereal vibrations 

 which we apprehend as light. But for the author's 

 defence (in many ways successful) against the obvious 

 objections to this view, we must refer to the book 



ilSflf. 



NO. 1847, VOL. 71] 



OUR BOOK SHELF. 

 Index of Spectra. (Appendix O.) By W. Marshall 



Watts, D.Sc. (Lond). Pp. 40. (Manchester: Abel 



Heywood and Son, 1904.) Price 3s. 

 This is the latest addition to the very useful series of 

 appendices which Dr. Marshall Watts has given to 

 his well-known " Index of Spectra." In it he has 

 brought together the arc spectrum of molybdenum by 

 Hassclberg, the spark spectra of calcium, scandium, 

 indium, beryllium, lithium, thallium, antimony, and 

 arsenic, by Exner and Haschek; of calcium, lithium, 

 thallium, and antimony, by Eder and Vaknta; of 

 radium, by Runge and Precht; and the oxy-hydrogen 

 flame spectra of lithium, potassium, rubidium, and 

 CEesium, by Ramage. Hasselberg's comprehensive 

 record of the arc lines of molybdenum takes up about 

 half the pages of the appendix. In the cases of 

 metals investigated both by Exner and Haschek, and 

 Eder and Valenta, the records are compared in 

 parallel columns. The oscillation frequencies cor- 

 responding to the wave-lengths of all the lines given 

 have been reduced by the compiler. 

 La Matiere, I'Ether ct les Forces physiques. By 



Lucien Mottez. Pp. 236. (Paris : Gauthier Villars, 



1904.) Price 4 francs. 

 The time is fast coming when the qualification which 

 will play the most important part in determining a 

 man's reputation as a pliysicist will be that he shall 

 abstain from writing books on the philosophy of 

 ether, matter, and the universe. The present book 

 discourses pleasantly about gravitation, heat, electri- 

 city and magnetism, polarisation of light, chemical 

 action, and such like matters. It is hardly the 

 kind of book to which a beginner would turn to 

 get his first lessons on physics, as the style is too 

 discursive, and it contains little but what an 

 average physicist either knows or has probably 

 thought of already ; and yet we can only say about 

 books of this kind, " still they come." Who reads 

 them? 

 The Uses and Wonders of Plant-hairs. By Kate E. 



Styan. Pp. iv + 65; with plates. (London: Bemrose 



and Sons, Ltd.) Price is. 

 The nature and purpose of plant-hairs will have 

 occurred to many teachers as a favourable subject for 

 a course of nature-study. The presence or absence of 

 hairs in allied plants, even in the same plant when 

 growing under different conditions, their position and 

 form, their mechanism and use, afford plenty of 

 opportunity for consideration and deduction. The 

 book offers a fair rdsumc of facts, but it is not obvious 

 that the writer is recording personal observations, 

 and the appendix of illustrations loses some of its 

 value as no allusion is made to it in the text. 



LETTER TO THE EDITOR. 

 [The Editor does not hold himsetf responsible for opinions 

 expressed by his correspondents. Neither can he undertal;e 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for tliis or any other part of Nature. 

 No notice is taken of anonynious communications.] 



The Planet Fortuna. 

 .■\ltiiougii N.ature is sr.ircoly the proper place for a 

 disquisition on a Latin quotation, perhaps you will admit 

 of a further correction of " \V. T. 's " correction (p. 461) of 

 the lines quoted by " W. E. P." Numen is, I believe, 

 never used except in the sense of good luck, beinjj derived 

 from nuo, and signifying the nodding approval of the 

 gods; hence "Nullum numen habes, si sit prudentia," 

 would mean just the opposite to the obvious sense of the 

 passage. The best editions ijivp, in both the satires where 

 the line occurs, " Nullum numen abest," and this makes 

 sense. Kxcept for this word, " W. T.'s" version is 

 correct. Spencer Pickering. 



