II. — Some Peculiar Double Salts of Lead 



BY JOHN WHITE 



Although it has long been known that the sulfate of lead is 

 markedly soluble in aqueous solutions of alkaline salts of certain 

 organic acids, such as the acetates and tartrates of ammonium 

 and sodium, it does not appear to have been generally remarked 

 that this property of solubility applies also to other of the diffi- 

 cultly soluble lead salts. 



In the course of some other work dealing with compounds 

 of lead, it was observed that lead iodid dissolves to an appre- 

 ciable extent in a concentrated aqueous solution of sodium 

 acetate, yielding upon evaporation a white crystalline crust, 

 which was found to contain both lead and iodin ; subsequent 

 experiments have shown that the chlorid and bromid of lead 

 behave like the iodid under similar conditions. 



Upon search, it was found that the literature of the sub- 

 ject is very meager, this property having been previously 

 observed by only a few investigators, and that none of the 

 text-books of chemistry make mention of it. The first 

 notice of it is contained in an article by Poggiale,^ in which 

 he describes a complex salt as being formed by heating together 

 lead chlorid and basic lead acetate; to this he gives the 

 formula 



PdCh. PbOCimO-2^ I ^HiO. 



The published data concerning this salt is such as to lead to 

 the conclusion that it was very impure. Later, Carius- pre- 

 pared a somewhat similar compound by dissolving lead chlorid 

 in a water solution of lead acetate, to which he ascribes the 

 formula 



M««. Chem. (Liebig), LVI, 234 (1845); Compt. rend.^^, 1180. 

 ^Ann. Chem. (Liebig), CXXV, 87 (18G3). 



307 



