Notices respecting New Boohs. 529 



In this country it is at present one of the disadvantages of any 

 science which has important industrial applications, that the treat- 

 ment of it in the universities proceeds upon lines which are more 

 appropriate to the technical schools. In the course of a few years 

 the technical schools may afford a partial relief to the universities ; 

 but we cannot help thinking that the necessity of adapting their 

 lectures to the student of technology will always tend in some 

 measure to draw the attention of the university teachers away 

 from the development of the theory of their subject. Professor 

 FitzGrerald has, on more than one occasion, claimed for the 

 university teacher increased opportunity for " useless " research, 

 that is, for investigations of a theoretical character without any 

 visible practical applications. This claim is worthy of most serious 

 consideration at the present time. "While the future of our higher 

 technical schools is trembling in the balance, could not a division 

 of labour be effected which would relieve the university of some of 

 the teaching at present assigned to it ? 



In the work at present before us Professor van 't Hoff does not 

 tell us anything new concerning the nature of molecules ; he pos- 

 tulates the existence of reacting molecules just as in ordinary 

 dynamics force and matter are accepted as facts. But, by assuming 

 that the rate of decomposition of the substances involved in any 

 reaction is proportional to the concentrations of these substances, 

 he shows how a knowledge of the degree of complexity of the 

 reaction (as measured by the number of different kinds of molecules 

 taking part in it) can. be obtained. The assumption is justified by 

 experiment in a few cases ; in many reactions, however, disturbing 

 influences cause a departure from this simple law. The author 

 was therefore led to investigate the nature and magnitude of the 

 more obvious forms of disturbance, such as the action of the 

 medium in the case of liquids and of the walls of the containing 

 vessel in gaseous reactions. The influence of temperature on 

 chemical change is next discussed, and is naturally followed by an 

 inquiry into the conditions of chemical equilibrium, with special 

 reference to the relations between temperature and equilibrium. 

 The volume concludes with a chapter on affinity. 



The subject is one which affords much scope for research, and 

 we hope that the appearance of this translation will serve to direct 

 attention to it. Both the reviser and the translator have pei- 

 formed their duties with care, while the printing of the volume is 

 a good example of what Holland can produce — very different from 

 some of the specimens of English and typography which occasionally 

 reach us from that countrv. — J. L. H. 



