and the Surface- 'Tension of Solutions* 483 



The values of (M 2 %)* just given have not been taken 

 directly from the tables of " Further Studies/' but have been 

 obtained on the principle there established that in (M 2 Z)* the 

 atoms have the values Li 2'4, Na 3*5, K 4*6. CI 2*1, Br 2*7, 

 I 3*6, and N0 3 3*6. The values of M 2 /p 2 are given in 

 " Further Studies.''' In the last table the values of the ratio 

 in the last row are rather high for the Li compounds, but for 

 the Na and K compounds they agree with those in Table V., 

 though rather higher than the mean 7*25, which we shall see 

 to have been rather too small. 



The equation to apply to Rontgen and Schneider's data for 

 the compounds of these metals with C0 3 and S0 4 is 

 2 A 1 A 2 



and in the following table the values of (M 2 %)V2^ are taken 

 from table xxi. of " Further Studies," where they are 

 denoted by 2F e j — 



Table VII. 



Li 2 S0 4 . Na 2 S0 4 . Na 2 C0 3 . K 2 S0 4 . K 2 C0 3 . 



p 2 -076 -096 -074 -115 -094 



p 1064 1088 1-075 1-097 1*085 



a 7658 7-651 7752 7*651 7750 



iV.*/p.(Ai^-.» ' 80 -6 ° ' m * 68 * 75 



(M 2 2 g*/2* 7-3 7-8 6-2 8-9 7*6 



4-4 4-0 4-3 4-7 4-8 



The values of the ratio in the last row agree well with those 

 we found in Table V., from Volkmann's data ; Na 2 C0 3 does 

 not appear as an exception as it did before. 



For the haloid compounds of the dyad metals Valson's 

 data are available ( Comp. Rend, lxxiv.) for use in the equation 

 2 A. 1 A 2 



*IP*=Pl*\IPl + ^ I ^ PlPs*lW/f>lP* + ^^tf^P^P*' ^ 



Valson's values of a are given in an arbitrary unit, according 

 to which the value for water is 60*8, while in mgrm. per 

 millim. it is 7*464, so that all Valson's values for solutions 

 can be expressed in mgrm. per millim. The values of 

 (M 2 %)i are reckoned on the principle established in " Further 

 Studies," that (M 2 Z)*/25 for this type of compound is the sum 

 of parts F r /2 due to the metal R, and F s due to the halogen 

 S, Fr/2 having the following values (** Further Studies," 

 table xvii.), Mg 2*7, Ca 3*2, Sr 3*7, and Ba 4*2, while as 

 before F s for 01 is 2*1, Br 2*7, and I 3*6. For the Zn and 

 Cd compounds (M 2 %) * is taken from table xiv. The values 

 of (M 2 /p 2 ) are also given in " Further Studies." 



