H. L. Wells — Caesium- and Potassium-Lead Halides. 13 L 



The following table gives the approximate conditions under 

 which the iive samples which were analyzed were made. 



Volume 

 KC1. PbCl 2 . Volume. for IgKCl. 



A... 400e SOS 1100 co 2| cc 



B 400 80 1200 3 



C 150 40 450 3 



D 1@0 25 350 3 \ 



E 300 55 1300 4| 



The results of the analyses are as follows : 



Calculated for 

 A. B. C. D. E. 3KPb01, . H a O. 



K 11-38 11-10 10-79 10-90 



Pb.._ 57-46 57-68 57"43 57'94 57*14 57'73 



CI ... 29-91 29-87 29-81 29'70 



H„0_. 1-45 1-39 1-51 1-88 1-67 



100-20 100-04 100-00 



All the samples were thoroughly air-dried before they were 

 analyzed. By this treatment the crystals did not lose any of 

 their luster. A finely pulverized portion of sample A lost 

 only 0*02 per cent in weight after standing over concentrated 

 sulphuric acid for eight days. The same sample suffered an 

 additional loss of - 23 per cent when heated for twelve hours 

 in a steam drying-oven. The water was not rapidly given off 

 until a temperature of about 200° was reached. The salt 

 decrepitates when heated rapidly to about 200°, corresponding 

 in this respect to the salt which Remsen and Herty described 

 as anhydrous and to which they gave the formula KPbCl,. 

 There can be no doubt, therefore, that Remsen and Herty's 

 formula is incorrect. 



KPhJJl^. — This salt is formed in more dilute solutions than 

 those which produce the previously described compound. It 

 occurs, like that compound, in white prismatic crystals, but it 

 differs considerably from it in luster and form, so that the two 

 salts can be distinguished by microscopic examination. The 

 salt under consideration is anhydrous, and this fact makes it 

 easy to distinguish this compound, when pure, from the other. 



Four analyzed crops were made under the following condi- 

 tions : 



Volume 

 KC1. PbCl 2 . Volume. for IgKCl. 



A 200s 50? 1500 0c 7i cc 



B 150 30 1100 7£ 



C 150 20 1100 7£ 



D 250 55 1200 4A- 



