82 CHLORIDE OP AMMONIUM IN CHEMISTRY. 
ART. XXI. — ON THE APPLICATION OF CHLORIDE OF AMMO- 
NIUM IN ANALYTICAL CHEMISTRY. 
By Prof. H. Rose. 
Prof. Rose recently drew attention to the very great use 
that might be made of the chloride of ammonium in quanti- 
tative analysis, from its converting several metallic oxides, 
when heated with them, into chlorides; the more volatile 
chlorides escape, and can thus be separated from the less 
volatile. Not merely oxides, but likewise several sulphu- 
rets are converted by chloride of ammonium into chlorides ; 
for instance, the sulphurets of antimony, arsenic, tellurium 
and tin. The following additional observations respecting 
the behaviour of various bodies towards chloride of ammo- 
nium have been since published: — 
Titanates. — When titanic acid is calcined with chloride 
of ammonium, the ammonical salt is driven off, and the ti- 
tanic acid does not decrease in weight. 
Titanic acid forms with the alkalies only acid insoluble 
salts; they dissolve in hydrochloric acid, except when de- 
prived of their water by a red heat ; they are then perfectly 
insoluble. It is consequently very difficult to ascertain their 
composition, especially when it is desired not to determine 
their amount of water by the loss. However, this is very 
easily accomplished by treating them with chloride of am- 
monium. The amount of water is rirst determined by ig- 
nition, the calcined compound mixed with sal-ammoniac, 
the mixture heated to redness, and this operation repeated 
until no further increase in weight results. While the tita- 
nic acid continues unaltered, the alkali exchanges its oxygen 
for chlorine, and the entire composition of the anhydrous 
salt can therefore be calculated merely from the increase in 
weight, for the difference between the atomic weight of the 
