Table XI. 









Na Ac. 



Ca Form. 



Ca Ac. 



Ea Form. 



Ba Ac. 



•058 



•094 



•086 



•079 



•088 



1-0309 



10664 



10505 



1-0815 



1-0677 



7-486 



7-491 



7-363 



7-523 



7-392 



1-56 



1-08 



1-11 



•42 



•72 



73 



85 



9-8 



9-9 



11-2 



9-0 



8-2 



8-3 



4-7 



76 



and the Surface -Tension of Solutions. 487 



The mean value of cCpJa^M^M^/p^-^^H^ for these 

 compounds is 8*1, which is not far from the 8*5 found for the 

 inorganic compounds of types NaCl and MgCl 2 . 



Some transition cases between organic and inorganic com- 

 pounds can be studied by means of some data of Traube's for 

 formates and acetates of Na, Ca, and Ba, for which we can 

 calculate the values for (M 2 2 Z 2 )* hy using 2*9 for HCOO 

 and 3*8 for CH 3 COO, and 3*5 for Na, remembering that in 

 the case of the dyad metals (M 2 %)V2 5 for the formates and 

 acetates is found by adding the values just given for HCOO 

 and CH 3 COO to 3-2 for Ca and 4*2 for Ba. 



.Na Form. 



p 2 '075 



p 1-0598 



a 7-577 



Aa^/padA^)* ... 1-19 



(MA) 1 6-4 



70 



Here again the value of the ratio, except for Ba Form., is 

 not far from the 8*1 just found for organic compounds, or the 

 8*5 for inorganic of the types NaCl and MgCl 2 . 



The general result may, therefore, be stated that a value 

 of 1 A 2 a///3 2 (iA 12 A 2 ) 5 for water and a compound of a monad 

 metal with a monobasic acid, or for water and an organic 

 compound, can be got from the surface-tension of a dilute 

 aqueous solution according to the equation (10); for water 

 and a compound of a monad metal with a dibasic acid accord- 

 ing to (11) ; and for water and a compound of a dyad metal 

 with a monobasic acid according to (12) ; and that then from 

 this a value of (M 2 2 / 2 ) * for the dissolved substance can be got 

 by the equations 



(M 2 %)* = AM^M^)- V/ft 8-5 (A 2 A 2 )* \ (13) 

 for the types NaCl and MgCl 2 J ' ^ ° } 



(M 2 %)*= A(M 2 /p 2 ) V/^4 (A A) 1 X . (U) 



for the type K 2 S0 4 J' [ } 



to organic compounds we cannot say which of these forms 

 applies. 



Now we formerly took jAg/dA^A^ as being given pro- 

 visionally by 7*25/13 for the type NaCl, but in harmony with 

 the majority of our data this should be 8 '5/1 3 or '65, and for 



