348 Dr. Vest on Vestium. {[May, 
sulphate of vestium, boil the solid portion with an alkaline ley, 
and try the clear portion for vestium, after having treated it with 
caustic ammonia, to separate the iron, and filtered it. If it be 
green, it still contains some nickel. By decomposing it by pot- 
ash and evaporating, we obtain the oxide of vestium. 
Having by one or other of the methods just. described 
obtained a solution of vestium in muriatic acid, I examine 
whether or not the solution be pure in the following manner. 
The impurities are owing to the presence of nickel, cobalt, 
and iron. 
Nickel is known when a portion of the concentrated solution 
is precipitated by carbonate of potash, and the precipitate is 
digested in ammonia. If nickel be present, the ammonia 
assumes a blue or green colour; for a mixture of nickel and 
vestium colours ammonia green. 
The solution still contains a great deal of nickel, which will 
be known by the blue colour; it must be decomposed by carbon- 
ate of potash, the precipitate dissolved in sulphuric acid, and 
the rick must either be separated in crystals of sulphate of 
nickel-and-potash, or the whole being thrown down by carbon- 
ate of potash, some carbonate of ammonia is to be poured upon 
the precipitate ; and after some agitation, the liquid is to be 
passed rapidly through the filter. By this means, the vestium 
will be left upon the filter mixed with only a very small propor- 
tion of nickel ; and it may be still further purified by washing it 
with hot distilled water. The clear solution which passes 
through the filter contains most of the nickel; but it contains 
likewise some vestium, which gives it a green colour. 
It is very difficult to free vestium from cobalt. On that’ 
account, it is advisable to free beforehand the ore employed 
from every perceptible portion of cobalt pyrites. A portion of 
the cobalt indeed may be separated by means of carbonate of 
ammonia in the same way as the nickel; or we may proceed in 
this way. We may dissolve the vestium containing cobalt in 
nitric, muriatic, or sulphuric acid, evaporate to dryness, and 
dissolve off the cobalt salt, which is much more soluble than the 
other; but by this process, we lose a portion of the vestium. 
But I am not at present acquainted with any better method of 
separating these two metals from each other. 
The iron is detected in consequence of the blue colour which 
it strikes with prussiate of potash. The vestium may be freed 
from it by adding some nitric acid to the muriatic acid solution, 
heating to peroxidize the iron, and then throwing it down by 
means of a little caustic ammonia, and filtrating rapidly. But 
by this process, we lose a portion of vestium. [tried to sepa- 
rate the iron by means of prussiate of potash ; but the filtered 
solution remained always either blue or green. It may be thrown 
down from neutral solutions by means of succinate of potash or 
a benzoate. 
