132 II L. Wells — Caesium- and Potassium-Lead Hcdides. 



The analyses were as follows 



A. 



Potassium.. 6 -14 



Lead 6474 



Chlorine ... 28-11 



Water O'll 



B. 



5-97 

 66-43 



C. 



6-18 



65-85 



28-13 



D. 



6-07 

 65-72 



28-08 



Calculated 

 for KPb 2 Cl s 



6-20 

 65-65 

 28-15 



0-00 



99-10 100-16 99-87 100-00 



There was no indication of the formation of any other 

 double chloride as the dilution was increased beyond that 

 given for the above products, and when a solution containing 

 I s of KC1 in ll ce was used pure lead chloride was deposited. 



K^PoB r )\ . H 2 '. — This salt is obtained by dissolving lead 

 bromide in the most concentrated solutions of potassium 

 bromide. It forms brilliant, prismatic crystals which are 

 permanent in the air. The largest of these which were ob- 

 tained were about l mm in diameter and 5 mm in length. A num- 

 ber of crops were made under the following conditions : 



Volume 

 KBr. PbBr 2 . Volume. for lgKBr. 



A 400S 70S <700 co If 



B 400 90 700 If 



C 400 120 800 2 



D 400 130 650 lyV 



E 500 130 850 1 T V 



F ...500 130 775 1 T 6 T 



These products gave the following analyses : 



K. Pb. Br. H 2 0. 



A 12-51 34-25 51-47 2-50=100-73 



B 12-21 34-59 51-21 2-51 = 100-52 



C 11-89 34-47 51-14 2'44 = 99'94 



D 12-37 34-50 51-35 



E 34-26 51-40 2-61 



F 12-70 33-89 51-46 2-57 = 10062 



Calculated for ) 2-89 = 100-00 



K 2 PbBr 4 . H 9 j 



This salt is apparently stable in the air, but it loses water 

 very slowly over sulphuric acid. A finely powdered sample of 

 A lost 0*23 per cent after remaining 12 hours in the desiccator, 

 and the same portion suffered an additional loss 0*33 after 

 eight days. A sample which was not pulverized lost only 

 - 09 per cent in 12 hours and, in addition, 017 per cent in 

 eight days. About one-half of the water went off when the 

 substance was heated for 12 hours in a steam drying-oven. At 

 200° the water is rapidly and completely expelled. 



