104 On the Analogy between Solutions and Gases. 



initial concentration ; and the fraction x to denote that 

 portion which after contact with zinc sulphide has finally re- 

 acted, forming zinc chloride. Hence we have 



3*96 log-^p 3*57 log^ =const. ; 



and also 



V 0,11 = const. 



This function is really nearly constant : 



Volume (V). Portion reacted (x). - V°n 



(1 — or) 1 " 11 



1 0*0411 0-043 



2 0-038 0*0428 

 4 0-0345 0-0418 

 8 0*0317 0-0413 



Similar experiments with sulphuric acid, where i for H 2 S0 4 

 and ZnS0 4 is respectively 2*06 and 0*98, gave 



V*» 3 = const.: 



(1-a?) 1 ' 02 



and here also a; is nearly a constant, as is seen from the 

 following experimental numbers : — 



Volume V. Portion reacted (#). 



2 0-0238 



4 0-0237 



8 0-024 



16 0-0241 



5. The experiments of Engel on the solubility of magnesium 

 carbonate in water containing carbonic acid ( Comptes rendus, 

 c. pp. 352, 444) also deserve notice. The state of equili- 

 brium is 



MgC0 3 + H 2 C0 3 ^Mg (HC0 3 ) 2 ; 



and our formula leads to the following relation, where ^ = 2*64 

 for acid magnesium carbonate : — 



0*379 log C H . 2 co3—log C M g(Hco 3 ) 2 =K. 

 The number found was 



0-370 log Ch 2 co 3 — log C M g(Hco 3 ) 2 =K. 



6. Other experiments by the same author on the simul- 

 taneous solubility of copper and ammonium sulphates ( Comptes 

 rendus, cii. p. 113), are shown by the reversible equation 



CuS0 4 + (NH 4 ) 2 80. 4 ^Cu(NH 4 )o(S0 4 ) 2 . 



