28 



NATURE 



[March 15. 19 13 



If either of the rivals could thoroughly vanquish 

 the other, or if they could settle their few differ- 

 ent ■-, all would be well, but time alone will show 

 whether Ostwald was in this instance a friend or 

 foe of progress. 



The author's proposal to divide words at any 

 letter instead of by syllables would scarcely get rid 

 of the difficulty of spacing out the line. Inci- 

 dentally, one is led to hope that such blemishes as 

 the substitution of "Zukunft" for " Folgezeit " 

 (p. 484, line 4) and the adjective "vielfachen " for 

 the corresponding adverb (p. 384, penultimate line) 

 are accidental slips rather than premature reforms. 



The distinguished founder and editor of the 

 Zeitschrift fur physikalische Chernie is at his best 

 in discussing university problems, whether in 

 connection with his biographical notes on Curie, 

 van't Hoff, Abbe, and Ramsay (the latter was 

 originally written for Nature), or with the pro- 

 posed foundation of new universities at Hamburg 

 and Frankfort. He maintains that the unit of the 

 future university must not be the faculty, but the 

 laboratory, the institute, or the clinic. Teaching 

 must be by work rather than lecture, and the 

 work must be under the personal direction of a 

 capable and enthusiastic chief in close touch with 

 theoretical advances and practical problems. 



The process of reasoning by which the irreversi- 

 bility of all actual transformations of energy is 

 made a fundamental ethical principle is one of 

 daring originality. If, says Dr. Ostwald, occur- 

 rences were completely reversible (like ideal 

 mechanical processes), then any mistake or wrong 

 action could be completely annulled by reversing 

 it. In fact, the whole world-history would read 

 just as consistently backwards as forwards. What 

 gives purpose and value and choice to life is the 

 inevitable dissipation of energy. This must be 

 directed into the most fruitful channels and put 

 to the best use before it is lost in space. Peace is 

 more fruitful and less wasteful than war, hence 

 peace is good and war is bad. This is probably 

 the first occasion on which a general physical law 

 has been made the foundation of a system of 

 ethics. E. E. Fourxier d'Albe. 



THE PRESENT POSITION OF RADIO- 

 ACTIVITY. 

 Radio-active Substances and their Radiations. 

 By Prof. E. Rutherford, F.R.S. Pp. vii + 699. 

 (Cambridge University Press, 1913.) Price 155. 

 net. 



MUCH water has flowed under the bridge 

 since 1906, when the second edition of 

 Prof. Rutherford's "Radio-activity" was reviewed 

 in Nature by the present writer. Though its title 

 has been changed, the work is not essentially 

 NO. 2263. VOL. 91] 



different in plan from its predecessor. The funda- 

 mental aspect of the subject has not changed, but 

 the pioneer investigations have for the most part 

 been supplemented, and in a sense superseded, by 

 subsequent work traversing the same ground, and 

 the author has found it impossible to incorporate 

 the newer work satisfactorily without entirely 

 rewriting the book. 



A pioneer has to encounter all the uncertainties 

 of a voyage into the unknown. A vast expanse 

 often lies before him. He has great difficulty in 

 reaching the unknown country, and cannot survey 

 it in the leisurely and methodical manner which is 

 afterwards attainable. His first hurried impres- 

 sions must often be erroneous. It is no easy matter 

 to hold the due balance between the credit which 

 properly belongs to him and that due to the suc- 

 cessors who tread in the path which he has made. 

 The skilful way in which this has been accom- 

 plished is a feature of the present work. 



The process of gleaning after the original rich 

 harvest is as yet far from complete. It is an open 

 secret that Prof. Rutherford and his colleagues 

 are now engaged on a revision of their funda- 

 mental determination of the properties of the 

 a particles. We ma} - confidently expect that the 

 charge, the electrochemical equivalent, the velocity 

 of expulsion, and the number of a particles 

 emitted by radium will soon be established within 

 a fraction of 1 per cent. It is scarcely to be 

 hoped, however, that these researches will be so 

 immediately fruitful as were the less accurate 

 determinations which they will supersede. 



The mass of detailed knowledge which Prof. 

 Rutherford is now able to record may suggest 

 that the wonderfully productive vein opened by 

 Becquerel's discovery of radio-activity is ap- 

 proaching exhaustion. It may be that this view 

 is not without foundation. The number of radio- 

 active substances now known is no fewer than 

 thirty-four, as against twenty recorded in 1906. 

 It scarcely seems likely that the next six years 

 will see an equal addition to the number, though 

 prophecy on such subjects is notoriously rash. 



In this connection it may be remarked that pro- 

 gress has not for the last few years altogether 

 followed the lines that might have been antici- 

 pated. Some of the more obvious problems have 

 been little pursued, such as the isolation of pure 

 actinium and ionium and the determination of 

 their atomic weights. The position of actinium in 

 the disintegration series is still a mystery. V\ e 

 are still unable to state definitely whether atomic 

 transformation ever occurs without the emission 

 of any ionising radiation, though the steadily 

 diminishing proportion of products regarded as 

 " rayless " suggests an answer in the negative. 



