450 



NA TURE 



[September S, 1904 



questions has to be asked alike on many planes — 

 biological, psychological, economic, ethical, &c. 

 Thus does every initiative in science open up a whole 

 system of new lines of investigation. The student who 

 gives himself to Dr. Tayler's guidance will be carried 

 no little distance along several of these new lines of 

 research ; and, moreover, it will be surprising if, after 

 that initiation, the student does not himself acquire 

 the momentum of original investigation, for 

 evolutionist conceptions are applied by Dr. Tayler with 

 a fertility and a novelty as courageous as their results 

 are inspiring. 



His evolutionist doctrines cannot be adequately 

 summarised in the space here available. But two of 

 his main contentions may be noted. Looking at 

 western civilisation from the environmental point of 

 view, he sees two large formative processes at work. 

 There is a process which operates in the direction of 

 selecting the palaeogenic types and eliminating the 

 neogenic ; and there is a process which sociologically 

 runs counter to this, and operates in the contrary 

 direction, tending to select the neogenic types and 

 eliminate the palaeogenic. The social environment 

 which, in its characteristic domestic and occupational 

 phases, pertains to the plutocratic and the aristocratic 

 scheme of life is, in point of selective efficacy, stated 

 to be the sociological equivalent of the disease and 

 poverty, the crime and vice of the urban slums. In 

 contrast to the social selection exercised alike by im- 

 poverished and luxurious environments. Dr. Tayler 

 finds the counter process in the cultural activities 

 associated with most professional and some artisan 

 occupations. 



Such being the speculative foundations, it will be 

 readily seen that Dr. Tayler's practical policy of social 

 progress lies in environmental modification consciously 

 planned by the scientific sociologist. The immediate 

 practical question thus resolves itself into asking who 

 and where is the scientific sociologist and what are 

 his credentials? The human control of environmental 

 modification has hitherto— at any rate since the Re- 

 formation — lain with the statesman and politician, 

 and such theoretical guidance as the practical re- 

 former has received from theologian and historian, and 

 in later times from economist and journalist, has not 

 been without a certain element of scientific foundation. 

 But the guidance of a new spiritual order is appear- 

 ing. Indications of this are visible on all sides. To 

 say nothing of Mr. Wells and other competent popu- 

 larists, examples may readily be drawn from more 

 recondite sources. By the president of the Scottish 

 College of Physicians, medical men were recently ex- 

 horted, with missionary fervour, to organise a crusade 

 for the development of a hygienic conscience. From 

 the rostrum of the Sociological Society Mr. Galton has 

 preached a eugenic conscience. A recent presidential 

 address of the Anthropological Institute came very near 

 to preaching an ethnic conscience ; and have not the 

 psychologists for half a generation or more been 

 preaching a pedagogic conscience ? 



It is indeed manifest that we are here in contempla- 

 tion of that most thrilling spectacle of human drama 

 NO. 18 I 9, VOL. 70] 



— the birth-throes of a new spiritual power. And in 

 the new spiritual orders there will be, as always in the 

 past there have been, individuals of the militant type- 

 brethren not content with crook and cassock, book and 

 bell, but demanding the sword of temporal power. 

 In this respect the observation may be made that 

 great as is the theoretical and scientific interest of 

 Dr. Tayler's book, yet its practical symptomatic 

 interest is perhaps still greater ; for it is diffused with 

 the militant spirit, and thus it becomes a matter of 

 political concern to ascertain how many fighting 

 brothers of Dr. Tayler's calibre are to be found in the 

 order of the Neo-eesculapians. 



ELECTRICITY. OLD AND NEW. 

 Propagation de I'Electricite. By Marcel Brillouin. 

 Pp. vi + 398. (Paris: .\. Hermann.) Price 15 

 francs. 



IN this book we have a reproduction of a course 

 of lectures delivered by Prof. Brillouin at the 

 College de France during the session 1902-03. They 

 were presumably addressed to an audience possessing 

 already a fair knowledge of electrical theory. The 

 author, therefore, does not aim at giving a complete 

 and connected account of the subject, but, with a 

 freedom which less fortunate teachers will envy, selects 

 those parts which seem to him most interesting from a 

 historical or theoretical point of view. The subject 

 matter of the course now published falls under two 

 heads; first, an exposition of fundamental principles, 

 characterised by great fulness in the historical setting 

 and originality in the order adopted, and second, a 

 detailed discussion of certain special problems. The 

 style is admirably clear, and the whole book is 

 written with a freshness which makes it very interest- 

 ing reading. 



The title is taken to cover steady as well as varying 

 currents. Accordingly, the first four chapters are 

 devoted to an account of the work of the pioneers, 

 beginning with Cavendish — that wonderful human 

 electrometer who estimated P.D. by the kick in his 

 elbows — and coming down to Kirchhoff and Clausius. 

 The author traces very clearly the gradual progress 

 towards definiteness in the ideas of the magnitudes 

 which figure in Ohm's law. Of Ohm's work a 

 specially full account is given ; stress is laid upon the 

 fact that Ohm, in formulating his theories, was 

 iniiuenced constantly by the desire to coordinate ex- 

 perimental results, and was not, as is sometimes 

 represented, guided merely by an a priori analogy 

 between thermal and electrical phenomena. 



Following this historical introduction we have the 

 development of the theory of conduction in three 

 dimensions. Among the special cases dealt with are 

 the resistance of a circular cylinder treated by 

 Bessel's functions, and the " end-correction " for a 

 wire by Lord Rayleigh's method of approximations. 



The discussion of varying currents is next taken 

 up, beginning with the case in which the influence 

 of capacity only needs to be considered. An excellent 

 account is given of Lord Kelvin's theory of the cable. 



