Some Peculiar Double Salts of Lead 13 



acetic acid is not necessary, appearing in fact to operate against 

 the reaction. Only very slight cooling is required for the salt 

 to separate, which it does rapidly, coming out as glistening, 

 pearly white scales, forming almost a solid mass in the vessel. 

 These were redissolved by adding more alcohol and heating, 

 when on cooling they were obtained in larger flakes. For 

 washing, a mixture of ethyl acetate and alcohol was used, 

 containing 2 to 3 per cent of potassium acetate, but, on account 

 of the tendency of the thin flakes to pack together on the filter, 

 much difficulty was experienced in washing them thoroughly, 

 as it must be done rapidly, otherwise decomposition sets in. 

 The analyses show that not all of the excess of the potassium 

 acetate had been removed. The drying was accomplished in 

 the same manner as with the sodium salt; the dry substance 

 is fairly stable. The same method of analysis was used as 

 with the sodium compounds. 



The following results were obtained : 



0.2463 gram substance gave 0.1494 gram lead sulfate and 0.0517 



gram potassium sulfate, 

 0.2888 gram substance gave 0.1760 gram lead sulfate. 

 0.4028 gram substance gave 0.081 1 gram potassium sulfate. 

 0.2795 gram substance gave 0.1355 gram silver iodid. 

 0.3010 gram substance gave 0.1436 gram silver iodid. 



Another preparation gave : 



0.2868^ gram substance gave 0.1743 gram lead sulfate. 



0.4422^ gram substance gave 0.2686 gram lead sulfate. 



0.3862 gram substance gave 0.0799 gram potassium sulfate. 



0.2591 gram substance gave 0.1235 gram silver iodid. 



0.4211^ gram substance gave 0.1648 gram COo and 0.0464 gram 



H.O. 

 0.3727^ gram substance gave 0.1463 gram CO 2 and 0.0409 gram 



H,0. 



VI am indebted to Miss Mary L. Fossler, of the University of Nebraska, 

 for these results. 



3^9 



