the Carinthian Molybdate of Lead. 303 
T now proceeded to examine the ore with the acids. 
As the results which I obtained when the ore was digested 
with nitric acid were the same as those mentioned by Mr. 
Klaproth, I shall not repeat them, but shall only observe, 
that it does not appear possible to decompose the ore com- 
pletely by means of this acid. 
§ IX. Molybdate of Lead with Muriatic Acid. 
240 Grains of the purified ore in fine powder were put into 
a glass matrass, with three ounces of pure muriatic acid. 
The matrass was then placed in a sand bath ; in about an 
hour the whole was dissolved, excepting some muriate of lead, 
which I dissolved by pouring water on it. 
After this there only remained a very small residuum of 
siliceous earth. 
A. The solutions were then added together, and formed 
a liquor which was transparent, and of a greenish-yellow co- 
lour. 
1. Prussiate of pot-ash produced a copious precipitate of 
molybdsena, in the form of a reddish-brown flocculent matter. 
B. Lixivium of carbonate of pot-ash precipitated a yellow- 
ish-white matter, and turned the liquor to a deep blue. 
C. Carbonate of soda had the same effect. 
D. Solution of carbonate of ammoniac produced a similar 
precipitate, and caused the liquor to become blue. 
acid before any precipitation could be made. The cause of this was, that the first 
liquor contained nitric acid in excess, which was afterwards expelled by the subse- 
quent evaporations. 
mdccxcvi. R r 
