( -<><» ) 



proved tliis property, induced by a statement made by Le Chatki.iek '). 

 The proof given does not directly bear, however, on the case that 

 in the liquid phase also the compound (van der Waals' so-called 

 complex molecule of salt and water) is found by the side of the 

 products of dissociation. 



2. Here follows another simple and quite general proof of the 

 property in question, in which specially the condition in the liquid 

 phase is taken into consideration, in which by the side of the com- 

 pound the products of dissociation occur in varying quantities. 

 Let us suppose there three kinds of molecules : 



those of the compound A;^ B,^ ;' number ?ï„ ^ 1 — « 

 those of ^ ; ,, ?ï, =^ v^a 

 those 0Ï B ; ,, n^ = i\a -\- x. 



So « is the degree of dissociation of the compound, and x the 

 excess of B e.g. 



Now from the property, that the molecular potentials of these three 

 substances, viz. ft„, ft; and jt^, are homogeneous functions of the 0''' 

 degree with respect to the numbers of molecules, follows immediately : 

 dn„ (In, da, 



ax ax <lx 



Here the differentiations with respect to x are to be taken total, 

 so that e.g.: 



d^o _ ófJQ öft„ da 

 dx d>r d« dx 



i.e. at constant temperature. 



[The above property is proved (loc. cit.) as follows. We have viz. 

 in consequence of the mentioned peculiarity of the functions (/„, (i, 

 and fij : 



OWd 0«j o«2 



0«„ OWj OWj 



So also ^;— being equal to v". etc. for n = r— and f j =; -— h 



') Verslagen Kon. Akad. van Wetenscliappen (4) V, p. 385 (1897). 

 -) These and the following properties were already proved by me in 1894. See 

 Z. f. Ph. Ch. 15, p. 459 et seq. ("Ueber die genauen I'^ormeln, etc."). 



