102 
RESEARCHES ON THE AMMONIAC AL COMPOUNDS. 
muriate of ammonia was procured, from which the ammonia 
was estimated at 6.72 per cent. 
The same process, substituting iodide of potassium for the 
sulphuret, gave the ammonia as 6.33. 
In all the theories previously advanced, oxygen is enume- 
rated as one of the ingredients in white precipitate, in suffi- 
cient amount to peroxidize the whole of the mercury. Accord- 
ing to the results of the decomposition by heat, the only pro- 
duct in which the oxygen is to be found is the aqueous vapor, 
which, if this element be present, should result from its union 
with the hydrogen of the ammonia, and thus liberating nitro- 
gen, which is also one of the products. To ascertain the 
amount of this vapor, a desiccating tube, sometimes containing 
lime, at others potassa, was attached to the apparatus used in 
this decomposition, its increase of weight denoting the amount 
of water retained. The results of four experiments, in the 
last of which no perceptible increase of the desiccating tube 
could be perceived, gave, as a mean, 0.583 per cent, of water, 
an amount so small as to afford strong presumption that it 
was derived from an imperfect drying of the precipitate. The 
average of the ammonia derived from the same experiments, 
the nitrogen being previously converted into ammonia and ad- 
ded to the amount of that alkali obtained, was 6.61 per cent. 
Summing up the results of these various operations, and tak- 
ing the mean of the whole, the composition of white precipi- 
tate will be 
Hg 78.60 
CI 13.85 
NH 3 6.77 
£ loss 0.78 
100.00 
From which the following formula may be deduced : 
Hg+Cl+NH 3 
Omitting the water as too small to constitute one of the con- 
stituents of the compound. 
