MODERN CHEMISTRY. 4'29 



hydrogen, nitrogen, and carbonic-acid gas ; of latent heat, 

 elective affinity, the composition of water and atmospheric 

 air, and the true nature of oxides and acids) can we con- 

 sider Chemistry to have acquired the foundation upon which 

 it now rests. Allied to the other experimental sciences by 

 similar methods of enquiry, yet vaster and more various in 

 its objects, it has undergone greater changes and expansion 

 than any besides; absorbing into itself some of these col- 

 lateral branches, and assuming such relation to others as to 

 indicate a future time when they may all be comprehended 

 under some more general system of physical truths. 



We have already named it as our object to present a short 

 outline of the more important changes and steps of progress 

 which mark the recent history of Chemistry; not limiting 

 ourselves to chronological order, but seeking what may best 

 illustrate the principles and present doctrines of the science, 

 and those methods of research by which it has attained its 

 actual condition. In doing this, we shall avoid as far as 

 possible all technicalities of language, and take such illus- 

 trations only as may be easily understood. A few general 

 remarks, however, are necessary in preface to those more 

 particular points on which we shall afterwards speak. 



In a recent article of this Review, we mentioned what we 

 consider the two most striking characteristics of modern phy- 

 sical science, viz. the more profound nature of the objects 

 and relations with which it now familiarly deals, and the 

 wider generalisations thence obtained ; and 2ndly, the greater 

 refinement and exactness, both of observation and experi- 

 ment, with which these objects are practically pursued. 

 Chemistry affords some of the most remarkable instances we 

 could select ; and the more closely we examine its present 

 state, and growing connection with other branches of phy- 

 sical science, the more striking will these illustrations appear. 



