Some Peculiar Double Salts of Lead 



II 



arated by picking out the coarse particles, but in general it was 

 found to be easier to effect separation by taking advantage 

 of the difference in the specific gravity of the two. To this end, 

 the whole product was shaken up in a stoppered flask with dry 

 ethyl acetate, when, upon standing a short time, the coarsely 

 crystalline substance settled almost at once, while the lighter, 

 fine portion remained for some time in suspension ; by decant- 

 ing, the separation could be effected. After several repetitions, 

 a fairly complete separation was accomplished ; the heavier 

 portion was found, upon analysis, to contain 24.61 per cent of 

 iodin, while the lighter contained 18.34. After making several 

 mechanical separations of the latter, it apparently reached a 

 constant value, the average being 18.81 per cent of iodin. 

 This method of separation, while it leaves room for doubt as 

 to the purity of the latter product, since one can not be sure that 

 it may not be mixed with sodium acetate, nevertheless led to 

 such uniform analytical results as to suggest that this was a new 

 substance. 



The following analytical results were obtained : 



0.4158 gram substance gave 0.1856 gram lead sulfate. 

 0.3477 gram substance gave 0.1559 gram lead sulfate. 

 0.4727 gram substance gave 0.15 14 gram sodium sulfate. 

 0.3477 gram substance gave 0.1109 gram sodium sulfate. 

 0.5179 gram substance gave 0.1803 gram silver iodid. 



On drying at 78 °C. for 7 hours in a vacuum of 650 mm., 

 0.5261 gram substance lost 0.0236 gram in weight. 



The most probable formula deduced from the analysis is 



317 



