ON ANTIMONIATE OF POTASH AND EARTHS. 39 
The aqueous solution of the sulphate of lirne affords, 
immediately on the addition of antimoniate of potash, 
a voluminous flocculent precipitate, which undergoes no 
change in its state of aggregation even after long standing. 
The liquid deposits no crystals. The smallest quantity of 
lime in salts of potash, especially in the carbonate of potash, 
may be detected instantly by the antimoniate of potash 
from the opacity produced. 
Salts of Magnesia. — Magnesia is thrown down from the 
aqueous solution of its salts, especially from that of the sul- 
phate of magnesia, in a voluminous and flocculent state by 
the antimoniate of potash. The antimoniate of magnesia 
redissolves to an almost clear solution in an excess of sul- 
phate of magnesia, but a few white flakes generally separate 
after standing. On this account no flocculent precipitate is 
produced in very dilute solutions of magnesia, except when 
a sufficient quantity of the test is employed ; small quanti- 
ties of magnesia are easily overlooked even when the solu- 
tion is but moderately dilute. Frequently, however, a crys- 
talline opacity results on agitating the liquid which might 
easily be confounded with that which is formed with salts 
of soda ; when the solution is excessively dilute, so that no 
precipitate results on the addition of the test, small crystals 
are deposited within twenty-four hours in considerable 
quantity. 
The crystals appear to be the neutral salt, since they do 
not form in an aqueous solution of carbonate of potash to 
which a small quantity of sulphate of magnesia has been 
added. Such a solution affords with antimoniate of potash 
a flocculent precipitate similar to the antimoniate of lime. 
The crystals are nearly insoluble in pure water, and but very 
slightly soluble in a cold dilute solution of carbonate of pot- 
ash, sulphuret of ammonium, and sulphuret of potassium ; 
they are rapidly decomposed by muriatic acid. Tersul. 
phuret of antimony is therefore immediately produced when 
