130 PL. L. Wells — Ccesium- and Potassium-Lead Halides. 



CsPh(Cl, Br\. — This occurred in small rectangular prisms, 

 like the chloride and bromide and having a yellow color inter- 

 mediate between them. Two crops gave the following- 

 analyses : 



Found. 



Ccesium 30'24 30-50 



Lead 44-23 43-55 



Chlorine 21-44 18-94 



Bromine 4-00 8"79 



99-91 101-96 



Ratio Br : CI 1:12 1:4-8 



CsPb^Cl, £r) 5 . — This was obtained in white plates resem- 

 bling the two double salts. Two products were analyzed. 



Found. 



Caesium 18-94 



Lead 51-40 51-97 



Chlorine 16-29 19-31 



Bromine 13-27 8'62 



99.90 

 Ratio Br: CI 1:2-8 1:5 



The Potassium Lead Halides. 



In studying these bodies care has been taken to record the 

 conditions under which they were made. These conditions, 

 in many cases are only approximately given, because uncertain 

 quantities of salts had often been removed from the solutions, 

 either for analysis or in order to obtain smaller and better 

 crops of crystals. A large number of analyses have been made 

 in some cases. This was due to the fact that the salts often 

 varied so little in appearance that it was necessary to analyze 

 many products in order to identify them and to be certain that 

 they were not different compounds. 



ZKPbCl % . PL % 0. — When lead chloride is dissolved in a hot 

 solution of potassium chloride which is so concentrated as to 

 be nearly saturated when cold, this double salt is deposited on 

 cooling. It forms brilliant prismatic crystals which are largest 

 in the most concentrated potassium chloride solutions. The 

 largest crystals obtained had a length of more than 10 mm and 

 a diameter of 1 or 2 mm . It was noticed that, when sufficiently 

 concentrated solutions were used, pure potassium chloride 

 crystallized upon this compound, and no evidence was ob- 

 tained of the existence of a double salt containing a larger 

 proportion of potassium chloride than this. 



