58 
Haying a small quantity of pure Potassium perchlorate 
at my disposal, I thought it might be 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 surrounded 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 4’7 22 grms. 
Weight of residue on evaporation 0 0333 grms. 
Weight of distilled water contained in the bulb at 
0°, 4 '75 7 5 grms. 
Weight of bulb itself, 5 '3954 grms. 
Hence the specific gravity of an aqueous solution of this 
salt saturated at 0° equals 1-0005: the percentage of salt in 
solution is Q-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 grms. 
Weight of residue on evaporation 0-0907 grms. 
Other weights as before. 
Specific gravity of aqueous solution saturated at 25 3 , 
1-0123. 
Percentage of salt in solution, 1-92. 
Solubility, 1 part in 52 '5 parts of water. 
O. Temperature 50° C. 
Weight of liquid in bulb 4 '798. 
Weight 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. Chem. Soc. [2] xit 203. 
