38 H. ROSE ON THE COMBINATIONS OF THE 
ammonium with salts of the oxide of ammonium, but as peculiar 
ammoniacal compounds, similar to the ammons. From their 
solutions in water, their amount of ammonia can by no means 
be precipitated entirely, but only in part, by chloride of pla- 
tinum. 
The combination of the sulphate of the chloride of sulphur 
(SC + 5 S) with ammonia.—An accurate knowledge of the 
composition of this compound is in so far of considerable interest, 
as by means of it some perhaps of the important theoretical ques- 
tions which occupy chemists at the present time may be answered. 
I have prepared this combination some time back, and made 
known the most important of its properties*. It was then, 
however, not perfectly pure; for it is exceedingly difficult 
to saturate the sulphate of the chloride of sulphur perfectly 
with ammonia. There is no volatile compound of chlorine in 
which it is effected with so much difficulty as in this. At the 
commencement, the ammoniacal gas must be conducted very 
slowly to the compound, which must be kept at the same time 
strongly cooled, in order to prevent all heating; for if the gas 
be passed too rapidly, and the vessel not kept cool, the whole 
mass becomes very much heated and yellow. The cause of 
this yellow colour, which arises from some sulphit-ammon 
(anhydrous sulphite of ammonia), I have formerly explained. 
Its presence is the cause why the solution of the ammoniacal 
combination gives with a solution of nitrate of silver a precipi- 
tate of chloride of silver which has a yellowish tint, arising 
from a slight intermixture of sulphuret of silver. The combi- 
nation is far from being completely saturated with ammonia, 
when the glass in which it is prepared and preserved contains 
free ammonia. After a long time this is absorbed; ammonia- 
cal gas must again be conducted to it, and the pieces of the 
compound be broken up as small as possible. This must be 
repeated from time to time, and continued so long, until free am- 
monia is observed in the vessel after a long interval. I have 
only succeeded, after the lapse of half a year, in saturating per- 
fectly with ammonia somewhat considerable quantities of the 
sulphate of the chloride of sulphur. 
The combination, carefully prepared, is perfectly white, and 
completely soluble in water. The best proof of its being satu- 
* Poggendorff’s dnnalen, Bd. xliv. p. 300. 
