For the successful application of bromine as an accelerating agent, we
are indebted to Mr. John Goddard of London, who at the time was
associated with Mr. John Johnson, now a resident of this city.

Preparation.--The mother-liquor containing bromides is treated with a
current of chlorine gas, which decomposes these salts, setting the
bromine free, which at once colors the liquid to a reddish brown color.
Ether is added and shaken with the liquid, until all the bromine is
taken up by the ether, which acquires a fine red color and separates
from the saline liquid.

{74}

Solution of caustic potash is then added to the ethereal solution,
forming bromide of potassium and bromate of potash. This solution is
evaporated to dryness, and the salts being collected are heated in a
glass retort with sulphuric acid and a little oxide of manganese. The
bromine is distilled, and is condensed in a cooled receiver, into a red
liquid.

Properties.--Bromine somewhat resembles chlorine in its odor, but is
more offensive. At common temperatures it is a very volatile liquid,
of a deep red color, and with a specific gravity of 3, being one of the
heaviest fluids known. Sulphuric acid floats on its surface, and is
used to prevent its escape. At zero it freezes into a brittle solid.
A few drops in a large flask will fill the whole vessel when slightly
warmed, with blood red vapors, which have a density of nearly 6.00, air
being one. It is a non-conductor of electricity, and suffers no change
of properties from heat, or any other of the imponderable agents. It
dissolves slightly in water, forming a bleaching solution.

Chloride of Bromine.--This as an accelerating agent is by many
considered superior {75} to the other Bromide combinations. It can be
readily prepared by passing a current of chlorine through a vessel
containing bromine. A mixture of two parts muriatic acid and one of
black oxide of manganese, should be put into a flask having a bent tube
to conduct the chlorine vapor into the bromine in another vessel. This
last vessel should also be supplied with a bent tube for conducting the
combined vapors with a third vessel or receiver. On the application of
the heat from a spirit lamp to the bottom of the flask, a current of
chlorine gas will be disengaged, and pass into the bromine, when it
readily combines, and gives off a vapor, which, when condensed in the
third vessel, forms a volatile yellowish-red liquid. It is best,