184 H. L. Wslls — Double Salts of Lead Tetrachloride. 



Calculated for 

 Found. (NH 4 ) 2 PbCl 6 . 



Ammonium 7'90 



Lead.... 44*61 45*39 



Chlorine 46'53 45'7l 



Potassium- Plumbic Chloride, K^PbCl % : — Chlorine was 

 passed into a solution saturated with potassium chloride, lead 

 chloride and hydrochloric acid at 0°, without producing the 

 double salt. Nikolukine has stated that the salt is soluble in 

 an excess of potassium chloride, and, acting upon this sugges- 

 tion, another solution was made, like the former except that 

 no potassium chloride was used. On mixing about equal vol- 

 umes of the two solutions and letting the mixture stand at 0° 

 for several hours, a well crystallized crop of the yellow double- 

 salt was obtained. The air-dry salt was analyzed. 



Calculated for 

 Found. K 2 PbCl s . 



Potassium 15-30 15*70 



Lead 41-91 41*55 



Chlorine 42-49 42-75 



99-70 10000 



Loss on heating 15*07 Cl a 14*25 



The above method of preparation gives a small yield, and it 

 would probably be better to use a method analogous to that by 

 which the ammonium salt was prepared. 



Rubidium- Plumbic Chloride, Pb % PbCl % : — When 65 g of 

 rubidium chloride were dissolved in 250 cc of water with 4 s of 

 lead chloride, no precipitate was produced by saturating the 

 solution with chlorine, but, on adding an equal volume of con- 

 centrated hydrochloric acid to this solution, an abundant, yel- 

 low, crystalline precipitate was produced. This was collected 

 on a filter, washed with hydrochloric acid containing chlorine 

 and air-dried. 



Calculated for 

 Found. Rb 2 PbCl 6 . 



Rubidium 28-62 28*93 



Lead 34*98 35-03 



Chlorine 35-85 36*03 



99-45 100-00 



Loss on heating 12-41 Cl 9 12-01 



A solution 35 cc in volume, made of equal volumes of 

 concentrated hydrochloric acid and water, and containing 

 •0619 g of rubidium and double the theoretical quantity of 

 lead chloride was saturated with chlorine. A precipitate of 

 the double salt was produced, which, after standing several 



