DEPRESSIONS FOR ELECTROLYTES—MACGREGOR. 233 
Loomis’s curves bend towards the left, suggests that the actual 
curve after starting at the 2—8 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 MgSO,, 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—4 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 as H,PO,, if it exist in solution in single mole- 
cules, may dissociate into 4, 3 or 2 ions, will it have a 3—4, 83—3, 
or 3—2 curve. If it have double molecules, its curve may be a 
6—8, 6—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 6—4 lines. A mean curve woula be just to the right of the 
3—2 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. 
