Some Peculiar Double Salts of Lead 9 



determined in the usual way, by burning with lead chromate. 

 The following results were obtained: 



■0.5585 gram substance gave 0.3273 gram lead sulfate and 0.0791 



gram sodium sulfate. 

 0.4078 gram substance gave 0.2396 gram lead sulfate and 0.0590 



gram sodium sulfate. 

 0.3957 gram of the white substance gave 0.1821 gram silver iodid. 

 0.3762 gram of the same gave 0.1723 gram silver iodid. 

 0.6849 g^am of the pale yellow substance gave 0.3143 gram 



silver iodid. 

 0.2494 gram substance gave 0.1032 gram CO^ and 0.0364 gram 



H.O. 

 0.4424 gram substance lost on heating 4^ hours 0.0255 gram 



in weight. 

 0.2237 gram substance lost on heating 8 hours 0.0133 gram in 

 weight. 

 The analyses lead to the formula 



The acetic acid of crystallization was determined by heat- 

 ing weighed portions of the pulverized substance in a 

 double walled vacuum air bath, containing alcohol as the 

 heating liquid. The heating was carried out at a temperature 

 of 78° C. and in a vacuum reading 650-710 mm. Under these 

 conditions the substance loses weight slowly, the weight 

 becoming constant after 33^ to 5 hours heating. In one 

 instance the temperature was raised, by substituting water in 

 place of alcohol in the jacket, to 98°C., but without causing 



315 



