ate of ammonium, which is the same substance as sal
ammoniac, but before it has been purified by sublimation. This is not
usually kept by druggists, but may be readily obtained of any of the
artificial manure merchants, at a very moderate rate; and its purity
may be readily tested by placing a portion of it on a red-hot iron,
when it should fly off in a vapour, leaving scarcely any residue.

2154. Coldness of the Materials used.

It is hardly necessary to add, that in icing wines, or freezing, the
effect is great in proportion to the coldness of the materials used;
therefore, every article employed, viz., the water, tubs, mixtures,
&c., should be as cool as possible.

2155. Blackbirds.

The cock bird is of a deep black, with a yellow bill. The female is
dark brown. It is difficult to distinguish male from female birds when
young; but the darkest generally are males. Their food consists of
German paste, bread, meat, and bits of apple. The same treatment as
given for the thrush (_See par._ 2456) applies to the blackbird.

2156. Food of Blackbirds.

The natural food of the blackbird is berries, worms, insects, shelled
snails, cherries, and other similar fruit; and its artificial food,
lean fresh meat, cut very small, and mixed with bread, or German paste.

2157. Thrushes.

A cock may be distinguished from a hen by a darker back, and the more
glossy appearance of the feathers. The belly also is white. Their
natural food is insects, worms, and snails. In a domesticated state
they will eat raw meat, but snails and worms should be procured for
them. Young birds are hatched about the middle of April, and should be
kept very warm. They should be fed with raw meat, cut small, or bread
mixed in milk with hemp seed well bruised; when they can feed
themselves give them lean meat cut small, and mixed with bread or
German paste, plenty of clean water, and keep them in a warm, dry, and
sunny situation.

2158. Canaries.

To distinguish a cock bird from a hen, observe the bird when it is
singing, and if it be a cock you will perceive the throat heaving with
a pulse-like motion, a peculiarity which is scarcely perceptible in
the hen. Feed young canaries with white and yolk of hard egg, mixed
together with a little bread steeped in water. This should be pressed
and placed in one vessel, while in another should be put some boiled
rape seed, washed in