532 



NA TURE 



[April 6, 1905 



and extraneous sources of heat must be avoided, and 

 the furnaces made practically self-contained, if any- 

 thing^ approaching perfection is to be attained. It 

 must be upon simplicity, ease of working, and free- 

 dom from complicated parts that the progress of liquid 

 fuel must chiefly depend. 



" The direct pulverisation of the oil is now coming 

 to be recognised as the proper method ; it is the most 

 efficient and the most economical." 



The next two chapters are devoted to discussing the 

 use of oil fuel for marine and naval purposes, but the 

 division into two chapters is hardly needed, as the 

 naval side of the question is scarcely touched upon, the 

 bulk of the matter in that chapter being taken up 

 with the trials of liquid fuel on the s.s. Mariposa, and 

 the tests made on land by the .\merican Liquid Fuel 

 Navy Board. 



The chapter on oil fuel in locomotives is an 

 excellent summary of the work of Urquhart and 

 Holden, whilst the use of oil fuel for metallurgical 

 and domestic purposes also receives some attention. 



The whole work compares very favourably indeed 

 with the far more pretentious treatise on the subject 

 which until now has been the only book of reference, 

 and everyone interested in this important question will 

 welcome Mr. North's excellent text-book. 



THE DYNAMICS OF CHEMICAL CHANGE. 

 Chemical Statics and Dynamics. By J. W. Mellor, 

 D.Sc. (N.Z.), B.Sc. (Vict.). Pp. xiii-l-S38. (Lon- 

 don : Longmans, Green, and Co.) Price 7!.-. 6d. 

 FOR some years past a marked increase of atten- 

 tion on the part of English chemists towards 

 the rapidly developing physical chemistry has been 

 observable. Until recently, however, the available 

 English literature on the subject was confined to 

 German translations, a state of things which is now 

 being in a large measure remedied. 



The present work forms one of the series of text- 

 books of physical chemistry edited by Sir William 

 Ramsay. According to the table of contents, four 

 chapters are devoted to the consideration of homo- 

 geneous reactions, and in succeeding sections the 

 initial periods in chemical change, heterogeneous 

 reactions, 'equilibrium and dissociation, electrolytic 

 dissociation, catalysis and the theory of chemical 

 change, fermentation, the influence of temperature 

 and pressure in chemical reactions, and finally ex- 

 plosions, are dealt with. 



Since the appearance of van 't Hoff's " Etudes de 

 Dynamique Chimique " a vast amount of work has 

 been done in connection with the problems involved 

 here, and the necessity for a summary of newly dis- 

 covered facts, a criticism of recent theories, and an 

 unbiased statement of our present position in regard 

 to the dynamics of chemical change and allied 

 problems must have been felt by many. Dr. Mellor's 

 work will, therefore, receive an undoubted welcome. 



The accumulated evidence on the nature of chemical 

 change resulting from kinetic studies leads the author 

 to favour the view that the " association " or 

 " intermediate compound " theories describe in the 

 most rational manner the mechanism of the majority 

 NO. 1849, VOL. 71] 



of reactions. Simple consecutive changes determine 

 the character of many apparently complex reactions. 



In connection with the determination of the number 

 of molecules taking part in reactions in gaseous 

 systems the author sounds a very necessary warning 

 note. The rate of decomposition of phosphine or 

 arsine is a frequent text-book illustration of one of 

 the methods employed, and the experimental data fit 

 in with the assumption that the reaction is unimole- 

 cular and non-reversible. But there is another side 

 to this and similar problems. It is not improbable 

 that the reaction takes place on the surface of the 

 walls of the containing vessel, and that its rate i^ 

 conditioned solely by the rate of absorption of the gas 

 by this surface. The course of the reaction will in 

 this case also be that of a unimolecular change. 



In the section on the measurement of chemical 

 affinity we meet old and familiar friends in the illus- 

 trations of the thermal and density methods of com- 

 paring the affinities of two acids. The very moderate 

 accuracy attainable in these methods, which involve the 

 small difference between two experimental quantities, 

 and in which corrections have frequently to be intro- 

 duced in consequence of secondarj' changes, is 

 scarcely ever sufficiently emphasised, and attention 

 might have been directed to this point. A method 

 depending upon the measurement of a property 

 possessed by only one component of a system has 

 obvious advantages, even if such methods are of 

 limited application. Whether Thomsen's relative 

 avidities and the relative ionic affinity coefficients are 

 always identical conceptions is left for the reader to 

 infer. 



Chapter x., dealing with catalysis and the theory 

 of chemical change, is most attractive reading. Here 

 the processes of slow combustion or auto.xidation are 

 discussed in the light of the theories of Brodie, 

 Schonbein, Clausius, van 't Hoff, Traube, Bach, 

 Engler and Wild, and the interesting phenomena 

 included under induced or sympathetic reactions arc 

 treated. In the chapter on explosions the account of 

 older work is supplemented by many new and interest- 

 ing facts. 



In the reviewer's opinion Dr. Mellor's work is to be 

 warmly recommended. The fact that it contains three 

 thousand or so references to original papers is in 

 itself evidence of its utility to the teacher, to the 

 advanced student, and to the physical chemist en- 

 gaged in research. H. M. Dawson. 



RECENT EARTHQUAKES. 

 A Study of Recent Earthquakes. By Charles Davison, 

 Sc.D., F.G.S. Pp. xii + 355 ; So illustrations. 

 (London:, Walter Scott Publishing Co., Ltd.) 

 Price 6s. 



IN this copiously illustrated volume Dr. Charles 

 Davison, whose seismological investigations, 

 especially those relating to British earthquakes, are so 

 w fll known, gives a popular account of the results 

 which have been arrived at by modern seismology. 

 The nuihod in which he treats his subject is one that 

 appcnjs to the general nadir. Rather than grouping 



