DEPRESSIONS FOR ELECTROLYTES MACGREGOR. 233 



Loomis's curves bend towards the left, suggests that the actual 

 curve after starting at the 2 3 intersection, may bend consider- 

 ably to the right before association or change of mode of 

 ionization has advanced sufficiently to change the direction of its 

 curvature. 



An electrolyte such as MgS0 4 , according as it may exist in 

 solution in single, double or triple molecules, and according to its 

 mode of ionization in associated molecules, may have a 2 2, 

 4 4 or 2, or 6 6, 4, 3 or 2 curve. Jones' curve lies to the 

 right of the 2 2 (1.85) line, bending towards it, and may quite 

 readily be a 2 2 (1.85) curve, changing to a 4 4t or 4 2 curve. 

 Loomis's lies between the 2 2 and 4 4 lines. A mean curve 

 would already, at a concentration .02, have crossed the 2 2 line. 

 The data, such as they are, are consistent with the depression 

 constant having a value of about 1.85, and would indicate single 

 molecules in dilute solutions, doubling of molecules at a very 

 early stage, and a steady increase in association through- 

 out. 



According asH 8 P0 4 ,if it exist in solution in single mole- 

 cules, may dissociate into 4, 3 or 2 ions, will it have a 3 4,3 3, 

 or 3 2 curve. If it have double molecules, its curve may be a 

 6 8, G 7, etc., to 6 2 curve, according to the mode of ioniza- 

 tion. Jones' curve runs down to the right of the 3 2 (1.85) 

 line, bending towards the line. Loomis's lies between the 3 2 

 and G 4 lines. A mean curve would be just to the right of the 

 32 line, and might readily run out at the 3 2 (1.85) inter- 

 section. This would indicate single molecules in dilute solutions 

 dissociating into two ions, an early occurrence of doubling of 

 molecules, and steady increase in the extent of association as 

 dilution diminished, the double molecules formed dissociating 

 into 4, 3, or 2 ions, but not into more. Although the coefficients 

 with which the curve is plotted are doubtful, the curve is so 

 nearly parallel to the axis of ionization coefficients, that even a 

 considerable error in their values would not affect the above 

 conclusions. 



