LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



FEBRUARY 1894. 



XIII. The Phases and Conditions of Chemical Change* 

 By V. H. Veley, M.A* 



" Was nun die Beobachter einer scientifisclien Methode 

 betriift, so haben sie bier die Wabl entweder dogniatiscb oder 

 skeptiscb, in alien Fallen aber docb die Verbindlichkeit sys- 

 tematiscb zu yerfabren." — Kant, Kritik der reinen Vernunft. 



Introductory* 



THE investigations on the subject of chemical change 

 published in the course of the past ten or twelve years 

 have more than ever rendered it difficult to give a satisfactory 

 answer to the questions : first, what is chemical change ? 

 and, secondly, what is the cause of its commencement ? It is 

 pretty plain, however, that in the long run these two problems 

 resolve themselves into the first. Recently there have arisen 

 two schools of thought, which, though widely opposed in 

 matters of detail, yet agree in the general principle that 

 chemical and electric phenomena are more exclusively related 

 to one another than to any other form of energy. On the 

 one hand, there are writers who hold that chemical change is 

 the reverse of electrolysis ; and, on the other, there are those 

 who consider that chemical change is conditioned by the 

 separation or dissociation of compounds into oppositely elec- 

 trified ions. Both schools have set forth answers to the 



* Communicated by tbe Autbor. 

 Phil. Mag. S. 5. Vol. 37. No. 225. Feb. 1894. N 



