ess; it crystallizes in
small cubes, and dissolves readily in water. This agent is extensively
employed in the paper and glass processes.

Bromide of Lime. This the principal accelerator used in the American
practice, and is the best of all dry combinations at present employed.
There are many reasons why the dry is advantageous; these are too
familiar to repeat.

"The bromide of lime may be produced by allowing bromine vapor to act
upon hydrate of lime for some hours. The most convenient method of
doing this is to place some of the hydrate at the bottom of the flask,
and then put some bromine into a glass capsule supported a little above
the lime. As heat is developed during the combination, it is better to
place the lower part of the flask in water at the temperature of about
50 deg. Fah.; the lime gradually assumes a beautiful scarlet color,
and acquires an appearance very similar to that of the red iodide of
mercury. The chloro-iodide of lime may be formed in the same manner;
it has a deep brown color. Both these compounds, when the vapor
arising from them is not too intense, have an odor analogous to that of
bleaching powder, and quite distinguishable from chlorine, bromine, or
iodine alone."

Farther on, I have given, in connection with accelerators, a process I
adopt, which is far less tedious and equally reliable.

Bromide of Silver--May be formed by pouring an alkaline bromide into a
solution of nitrate of silver, in the shape of a white, slightly
yellowish precipitate, which is insoluble in water and nitric acid, but
readily dissolves in ammonia and the alkaline hyposulphites. Chlorine
easily decomposes bromide of silver, and transforms it into chloride.

M. Biot has expressed his opinion, that it is not possible to find any
substance more sensitive to light than the bromide of silver. This is
true to a certain extent, but in combination with deoxidizing agents,
other preparations have a decided superiority over the pure bromide of
silver.

Bromide of Gold--Is readily prepared by adding a little bromide to the
brown gold of the assayers, and allowing it to remain some time under
water, or assisting its action by a gentle heat. It forms a salt of a
bright crimson color, but in its general properties is precisely
similar to the chloride used in gilding.

Bromide of Magnesia--Is prepared in the same manner as bromide of lime.

This mixture is particularly adapted for hot climates, and is used in