320 On Chemical Nomenclaticrc, 



ieen animated at each point of (his curve, with the same vis 

 matrix which it there really experiences^ and that' its velocity 

 at the first instant had been null. 



It is this proposition which we call the principle of the 

 preservation of active forces ; and whence we may conclude 

 that, 



In a system of hard bodies the movement of which cJmnges 

 ly insensible degrees ^ and which are not animated with any 

 vis motrix, the sum of the active forces is a constant qtian- 

 tity, i. e. the same for eve^-y instant. 



For in this cas-e we have by hypothesis p = 0, which 

 gives V = 0, and therefore 5 ?« V^ = 5 m K- ; an equation 

 besides which is extracted immedialely from that smpV dt 

 cosine R — 5mV€?V=0, found in XXIV^ which, on 

 account of p = 0, is reduced to s w V £? V = 0, the integral 

 of which completed is \ s m Y^ r=. \ s m YJ- =05 whence 

 follows the equation j; w V^ = ^ m K-. a. E. D. 



[To be continued.] 



LX. On Chemical Nomenclature, By a Correspondent. 

 To Mr, Tilloch. 



SIR, 



J. HE importance of an accurate and scientific nomenclature 

 being now admitted by every lover of chemistry, 1 shall 

 make no apology for suggesting what I consider an improve- 

 ment. The metalline salts are named after a plan which 

 is extremely defective. It proceeds upon the supposion that 

 no more than two oxides of any metal can combine with 

 the same acid. The salt whose base is the first of these 

 oxides is named as if there were no oxide present : thus, 

 the protoxide of iron and sulphuric acid form what is called 

 sulphate of iron. On the other hand, the salt which con- 

 tains the second of these oxides is known by oxy being 

 prefixed, as in the oxy- sulphate of iron. 



This mode of nomenclature is objectionable on several 

 accounts. 



1.3t, It is extremely deficient in tbe extent of application. 



as 



