148 ON THE DEPRESSION OF THE FREEZING-POINT 
As a change in the atmospheric pressure would cause a corres- 
ponding change in the thermometer, the freezing-point of the 
water used was determined about every three hours. The 
temperature of the room was kept as low and as constant as 
possible during the experiments, and no observation was made 
when it was above 5°C. 
Since the freezing of my solutions was started about 0.1 
degree below the freezing-point, the amount of ice formed was so 
small that the correction usually applied for the change in con- 
centration, and, therefore, in the depression, comes within my 
limit of error. Thus the results are recorded without any 
correction. ; 
Simple Solutions. 
With the electrolytes K Cl, NaCl, and H Cl, there is only 
one possible way for their molecules to dissociate, namely, into 
two ions. Hence expression (1) reduces to 
t) 
For the determination of the values of M, the other quanti- 
ties, 6, 7 and @ are obtained from observations on simple solu- 
tions; @ being taken equal to the ratio of the specific molecular 
conductivity to the specitic molecular conductivity at infinite 
dilution. As the solutions are at a temperature of about 0°C. in 
the determination of the freezing-point, the ionization coefficients 
should be obtained at approximately the same temperature. 
For this purpose measurements were made of the conductivity 
at 0°, both of solutions of the range of concentration used in the 
observations of the freezing-point and also of very dilute 
solutions of the electrolytes. These latter measurements are 
required for the determination of the specific molecular con- 
ductivities at infinite dilution for 0°C. 
Determination of the Specific Molecular Conductivities at 
Infinite Dilution for O°C. 
A series of simple solutions varying in concentration from 
.01 to .0001 in the case of the salts, and from .01 to .001 for the 
