484 COBALT SULPHATE SOLUTIONS—MORRISON. 
of hydrated salt to 100 molecules of water. Hence, according to 
him, 1.04123 is the density at 20° ©. of a solution containing 
4.1434 per cent. of anhydrous salt. My experiments, as repre- 
sented by the above formula, give 1.04508 as the density of this 
solution. Wagner} gives 1.0860 as the specific gravity at the 
temperature of the laboratory (not given) of a solution contain- 
ing 7.239 per cent. of anhydrous salt. If we take the temperature 
of the laboratory to have been 15° C., and assume that his spe- 
cific gravities were referred to water at 15° C., the density of 
this solution according to him would be 1.08581. My experi- 
ments would make it 1.08117. Wagner’s result is thus about as 
much greater than mine for this solution as Nicol’s is less than 
mine for the solution which he examined. 
The above observations were made in the Physical Laboratory 
of Dalhousie College, Halifax, N. 8. 
+ Wied Ann, XVIII, (1883), p. 269. 
