48 ROYAL SOCIETY OF CANADA 



The Ratios of Potassium Chloride to Silver Chloride. 



average 



5-2022 



39-137 



average 



69-115 



39-141 



Mean value of Series I and II. 



39 139 



The Preparation of Pure Material. 



Chemically pure potassium sulphate was successively crystallised 

 five times, the mother liquor being discarded each time, and the crystals 

 carefully drained and washed with a little water. Barium chloride 

 •was purified first by precipitating three times with hydrochloric acid, 

 then four times with carefully purified alcohol. ^o indication of the 

 presence of strontium or calcium could be found when the residue from 

 the last two mother liquors was examined in the spectroscope. 



The pure potassium sulphate was now converted into the chloride 

 by means of the purified barium chloride, still leaving a slight excess 

 of potassium sulphate in the mother liquor. The potassium chloride 

 was then reprecipitated eight times with hydrogen chloride, generated by 

 boiling a concentrated solution of hydrochloric acid. After the third 

 precipitation no barium could be detected by means of the spectroscope 

 in the residues from the mother liquors, although traces were found in 

 the first two. These final precipitations were all carried out in platin- 

 um vessels. 



Silver: — The metho'd followed in purifying the silver was much 

 like that employed by Eichards and Parker ^ in their investigation on 



'* Proc. Amer. Acad., 1896, 32, .55. 



