ACTION OF SOME OF THE ALKALINE SALTS 

 UPON THE SULPHATE OF LEAD. 



It has been for some time known that certain neutral salts 

 possess the property of dissolving to some extent the sulphate 

 of lead, which properly belongs neither to the acids nor bases 

 constituting these salts. By referring to Berzelius' Chemistry 

 it will be found that the acetate and nitrate of ammonia are 

 among the number. " One part of the sulphate was dissolved 

 in 47 parts of a solution of the acetate of specific gravity 1.036, 

 and in 172 parts of a solution of the nitrate of specific gravity 

 1.144." In the Annalen der Ghem. und Phar. (vol. xxxiv, 235) 

 will be found the following statement under tjhe head of Reac- 

 tionen: "Sulphate of lead is easily dissolved, and in a large 

 quantity, by a solution of neutral tartrate of ammonia; a con- 

 centrated solution forms after some time a stiff jelly like silica." 

 This last is no doubt a double tartrate of lead and ammonia. 



I had also observed some time previously that a solution 

 of the citrate of ammonia, when poured upon the sulphate 

 of lead and allowed to stand, altered the character of the sul- 

 phate, and this, with the other fact above stated, led to the 

 examination of what was really the action of these as well as 

 other ammoniacal salts in general upon the sulphate in ques- 

 tion, and it was found that in every case it was decomposed. 



Citrate of ammonia. — If a solution of citrate of ammonia be 

 poured upon the sulphate of lead and shaken together, the clear 

 solution will be found to contain the sulphate of lead, as shown 

 by hydrosulphuric acid, and a salt of baryta (taking care in 

 testing with the baryta to acidulate first with pure nitric acid, 

 to prevent the formation of the citrate of baryta.) If they be 

 allowed to remain several weeks in contact, the solution will be 

 found to contain more lead, the sulphate having undergone 

 decomposition, sulphate of ammonia and a double citrate being 

 the result ; as this latter salt is not very soluble, a large portion 

 of it remains in the form of a precipitate. The rapidity of this 



