316 PRINCIPLES OF CHEMISTRY 



commencement, about 2-6. per cent, of the salt taken was decomposed in 

 the course of one minute, whilst after an hour the rate was about 

 0'5 per cent. The same phenomena are observed in every case which 

 has been investigated, and this branch of theoretical or physical 

 chemistry, now studied by many, 27 promises to explain the course of 

 chemical transformations from a fresh point of view, which is closely 

 allied to the doctrine of affinity, because the rate of reaction, without 

 doubt, is connected with the magnitude of the affinities acting between 

 the reacting substances. 



2l The researches' made by Hood, Van't Hoff, Oetwald, Warder, Menschutkin, Kono- 

 valoff, and others have a particular significance in this direction. Owing to the com- 

 parative novelty of this subject, and the absence of applicable as well as indubitable 

 deductions, I consider it impossible to enter into this provinc'e of theoretical chemistry, 

 although I am quite confident that its development should lead to very important results, 

 especially in respect to chemical equilibria, for Van't Hoff has already shown that 

 the limit of reaction in reversible reactions is determined by the attainment of equal 

 velocities for tho opposite reactions. 



