to the
exclusion of every other. It contains, when pure, 25.7 per cent ammonia.

It is now manufactured of excellent quality for agricultural use, and
when good, contains from 95 to 97 per cent of actual sulphate, the
remainder consisting chiefly of moisture and a small quantity of fixed
residue; but specimens are occasionally met with containing as much as
10 per cent of impurities, which, as its price is high, makes a material
difference in its value. Inferior descriptions are also occasionally
sold, among which is a variety distinguished by containing a large
quantity of water and fixed salts, although it appears to the eye a good
article. Its composition is--

I. II.
Water 9.05 5.77
Sulphate of ammonia 79.63 85.21
Fixed salts 11.17 9.02
------ ------
100.00 100.00
Ammonia 20.55 21.94

An article called sulphomuriate of ammonia is also sold for agricultural
use. It is obtained as a refuse product in the manufacture of magnesia,
and is a mixture of sulphate and muriate of ammonia, with various
alkaline salts. It differs somewhat in quality, and is sold by analysis
at a price dependent on the ammonia it contains.

I. II.
Water 14.49 25.39
Sulphate of ammonia 62.55 47.79
Muriate of ammonia 15.3 ...
Sulphate of soda ... 9.12
Sulphate of magnesia ... 18.38
Chloride of potassium 4.75 2.94
Chloride of sodium 17.35 0.35
------ ------
100.00 100.00
Ammonia 16.50 11.28

The quality of sulphate of ammonia may generally be judged of from its
dry and uniformly crystalline appearance, and it may be tested by
heating a small quantity on a shovel over a clear fire, when it ought to
volatilize completely, or leave only a trifling residue. Some care,
however, is necessary in applying this test, as in the hands of
inexperienced persons it is sometimes fallacious. The salts of ammonia
may be applied in the same way as guano; but they are most
advantageously employed as a top-dressing, and principally to grass
lands. In this way very remarkable effects are produced