58 
Having a small quantity of pure Potassium perchlorate 
at my disposal, I thought it might he interesting to deter- 
mine the solubility of this salt in water at different temper- 
atures. 
The apparatus employed was similar to that described by 
Hannay.^' 
The salt was placed in a small test tube to which a ther- 
mometer was strapped, the whole being surrouiided with ice 
or water maintained at the proper temperature. 
The following were the results obtained. 
A. Temperature 0° C. 
Weight of liquid in the bulb 4 '72 2 grins. 
Weight of residue on evaporation 0-033 3 grins. 
Weight of distilled w^ater contained in the bulb at 
0°, 4 ’75 75 grins. 
Weight of bulb itself, 5‘3954 grins. 
Hence the specific gravity of an aqueous solution of this 
salt saturated at 0° equals 1’0005: the percentage of salt in 
solution is 0’705 : and the solubility of the salt is 1 part in 
142*9 parts of water. 
B. Temperature 25° C. 
Weight of liquid in bulb 4*7418 grins. 
Weight of residue on evaporation 0*0907 grins. 
Other weights as before. 
Specific gravity of aqueous solution saturated at 25°^ 
1-0123. 
Percentage of salt in solution, 1*92. 
Solubility, 1 part in 52*5 parts of water. 
C. Temperature 50° C. 
Weight of liquid in bulb 4*798. 
V/eight of residue on evaporation 0*243. 
Specific gravity of aqueous solution saturated at 50°, 
1*0181. 
Percentage of salt in solution 5*07. 
Solubility, 1 part in 15*5 parts of water. 
J. Cliem. Soc. [2] sii, 203. 
