Notices respecting Neio Books. 515 



much to me, I cannot consider my opinion as proved, and there- 

 fore give it with some reserve as one of several hypotheses. ... If 

 in solutions I see and can frequently prove distinct evidences of 

 the existence of those definite compounds which form the more 

 generalized province of chemical data, I could not refrain from 

 going into certain dttails respecting solutions ; otherwise there 

 would have remained no trace of that general idea, that in them 

 we have only a certain instance of ordinary definite or atomic 

 compounds, subject to Dalton's laws." 



In accordance with this statement many allusions to the current 

 theories of solution will be found throughout the work, generally, 

 in the form of foot-notes. A summary of the two aspects of the 

 solution question, the physical and the chemical, is given in a 

 lengthy note, running through pages 64-67 of the first volume, 

 and from this it will be seen that the author does not regard these 

 apparently conflicting views as irreconcilable. At the same time 

 he correctly points out that solution cannot be a purely physical 

 phenomenon since it " does not take place between any two 

 substances, but requires a special and particular attraction or 

 affinity between them." In other words, the purely chemical 

 aspect of solution cannot be ignored. 



In noticing the first English edition some six years ago we had 

 occasion to call attention to the suggestiveness of the foot-notes, 

 and a re-examination of the present edition from this point or! 

 view will serve to bring out even more forcibly the extraordinary 

 breadth of the author's grasp of his subject. All the fundamental 

 philosophical conceptions which have been introduced into chemical 

 science appear to have been considered, not simply in the 

 perfunctory "professorial" sense, but with the calm deliberation 

 of an original mind given to weigh doctrines as well as to enunciate 

 them in the lecture-room. Many of the notes are in fact of the 

 nature of disquisitions on special doctrines, and are often complete 

 from the historical point of view as well as concise in literary 

 treatment. It remains only to indicate that there is a marked 

 improvement in the translation of the present edition, and the 

 ambiguities which were observable here and there in the text of 

 the earlier edition have been removed. The third appendix of 

 the former edition is now replaced by a paper on Argon written 

 in 1895, which is extremely interesting as indicating that the 

 author still had a lingering idea that this gas might be a polymeric, 

 condition of nitrogen formed under natural as distinguished from 

 artificial laboratory conditions. Helium was too recent a discovery 

 to be treated of at length, and one can only regret that we have 

 not the advantage of Mendeleeff's latest and most matured views 

 on the influence of the discovery of these inert gases on the 

 periodic arrangement of the elements. In confirming the favour- 

 able opinion which was formerly expressed with respect to the 

 value of this treatise — an opinion which the new edition enhances 

 in a very high degree — we may add that both translator aud 

 editor have done their work remarkably well. 



