44 F. H. Storer on the Carbonates of Lime and Baryta. 
soda. lorid of sodium and of potassium also retard in a 
with equal facility by mixing their solution with that of an alka- 
line carbonate and adding a solution of a lime or baryta salt to — 
the mixture. A few examples will illustrate this point. : 
(1.) A solution of chlorid of calcium produces no precipitate, 
except on boiling, when added to a mixed solution of carbonate — 
of soda and sulphate of soda excepting when the carbonate 18 — 
in excess. In this experiment the sulphate of soda may be re — 
placed by any of the alkaline sulphates or chlorids. Ps 
(2.) A solution of;chlorid of barium produces no precipitate, 
except on boiling, when added to a mixed solution of carbonate 
of soda and chlorid of ammonium and if the latter be ) 
in considerable quantity there will be no precipitate even On — 
boiling. When the chlorid of ammonium is  cectaa in smaller — 
uring twenty-four hours, but on being filtered and the cleat — 
filifate oiled, 
anes 
(4.) When a mixed solution of carbonate of soda artd nitrate 
of potash is quickly added, in large excess, to a small quantity — 
of a solution of chlorid of barium or of hydrate of baryta, 20 — 
immediate precipitate is produced except on boiling. ee 
The most remarkable solvent action which I have noticed 18 
seen in the inability of the alkaline carbonates to precipitate — 
baryta, and especially lime, from their solutions, when added in — 
great excess. That such solvent power exists may be proved — 
by precipitating a small quantity of a salt of lime with carbon — 
ate o and then redissolying the precipitate in a very — 
great excess of the precipitant. Buta much more satisfactory — 
proof may be obtained by adding quickly a large excess of the — 
solution of the alkaline carbonate to a small portion of a dilute © 
solution of a lime or baryta salt; so quickly that the precipitate — 
