It will easily be understood that the bromide of iodine can be used with a greater or less quantity of water without altering the proportion which exists between the bromine and iodine." This article forms a very good dry accelerator, and is by some persons thought superior to all others, as it works with great uniformity, and is less liable to scum the plate in coating at high temperatures, or when the thermometer indicates a heat above 60 deg.
Bromide of Potassium--Is prepared by mixing bromine and a solution of pure potass together, and evaporating to dryness; 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.