ORES. 
melted mass is then to be dissolved in hot water. 
white precipitate gradually separates, which is the 
white oxide of titanium. This is all that is necessa 
ry to analyse the first species. But when iron and si 
lica are present, the following method of Chenevix may 
be adopted. Saturate the alkaline solution with muri 
atic acid. White oxide of titanium precipitates. Se 
parate the precipitate, and evaporate the solution to 
dryness. Redissolve the residuum in water. The si 
lica remains behind. Precipitate the solution by an al 
kali ; add the precipitate to the white oxide obtained at 
first, and dissolve the whole in sulphuric acid. From 
this solution phosphoric acid precipitates the titanium, 
but leaves the iron*. 
The third species, which contains lime and no iron, 
is to be fused with potass, dissolved in muriatic acid, 
and the silica separated in the usual way. After this 
the titanium is first to be separated from the muriatic 
solution by ammonia ; and afterwards the lime by an 
alkaline carbonat. 
XXI. Ores of Chromum. 
1. Vauquelin analysed the chromat of lead in the fol 
lowing manner: When boiled with a sufficient quan 
tity of carbonat of potass, a lively effervescence takes 
place ; the acid combines with the potass, and the car 
bonat of lead is formed, and remains undissolved. It may 
be dissolved in nitric acid, and its quantity ascertained by 
precipitation with sulphuric acid. Or the chromat may 
be treatéd with muriatic acid ; muriat of lead precipi 
tates, and chromic acid remains in solution. This process 
* Nicholson's Journal, v. 132. 
L 2. 
163 
Chap. III. 
Menadher 
nite. 
Chromat of 
lead.