e84 Experiments on Allanite. 
culty, both in nitric and sulphuric acids.. The solutions 
had a reddish-brown colour, a slight metallic astringent 
taste, but no sweetness. 
f. The solution of this matter in nitric and muriatic acid, 
when examined by re-agents, exhibited the following phe- 
nomena: 
(1.) With prussiate of potash, it threw down a white 
. precipitate in flocks. It soon subsided; readily dis- 
solved in nitric acid; the solution was given. 
(2.) Prussiate of mercury. A light yellow precipitate, 
soluble in nitric acid. 
(3.) Infusion of nut galls. No change. 
(4.) Gallic acid. ‘No change. 
(5.) Oxalate of ammonia. No change. 
(6.) Tartrate of potash. No change. 
(7.) Phosphate of soda. No change. 
(8.) Hydro-sulphuret of ammonia. Copious black flocks, 
Liquor remains transparent. 
(9.) Arseniate of potash. A white precipitate. 
BE Pe a ae Copious — yellow-co- 
(11.) Carbonate of soda. .... > Joured flocks; readily 
(12.) Carbonate of ammonia. } dissolved in nitric acid, 
(13.) Succinate of ammonia. A white precipitate. 
(14.) Benzoate of potash. A white precipitate. 
(15.) A plate of zinc being put into the solution in mu- 
riatic acid, became black, and threw down a black 
powder, which was insoluble in sulphuric, nitric, 
muriatic, nitro-muriatic, acetic, and phosphoric 
acids, in every temperature, whether these acids 
were concentrated or diluted. 
(16.) A plate of tin put into the nitric solution, occasioned - 
no change. 
(17.) A portion being inclosed in a charcoal crucible, and 
exposed for an hour to the heat of a forge, was not 
reduced to a metallic button, nor could any trace of 
it be detected when the crucible was examined. 
These properties were all that the small quantity of the 
matter in my possession enabled me to ascertain. They 
unequivocally point out a metallic oxide. Upon comparing 
them with the properties of all the metallic oxides known, 
none will be found with which this matter exactly agrees. 
Cerium is the metal the oxides of which approach the 
nearest. The colour is nearly the same, and both are pre- 
cipitated white by prussiate of potash, succinate of am- 
monia, and benzoate of potash. But, in other respects, 
the two substances differ entirely. Oxide of cerium is pre- 
cipitated 
