54 ROYAL SOCIETY OF CANADA 
tion may probably be put at 0°0015 degree. If this estimate is approxi- 
mately correct, the above table shows that the agreement between the 
observed and calculated values is very satisfactory for these mixtures, 
except in the case of the two strongest solutions. | 
Thus it may be concluded that the depressions of the freezing-point 
of mixtures of solutions of hydrochloric and sulphuric acids up to an 
average concentration of 0:2 gramme-molecule per litre can be calculated, 
according to the dissociation theory, within the limit of the error involved 
in observation and calculation, on the assumption that the sulphuric acid 
dissociates into H, H, and SO, as ions, and by taking the value of the 
molecular depression of an electrolyte in a mixture to be equal to its 
value in a simple solution of the same total concentration. 
