olor, recoat about one sixth of the time of first coating.

I will here again remark, that the exact color of the coating is not
essentially provided a proper proportion is preserved.

I have never seen it stated, though it be a fact worthy of note, that a
proportionate time for coating over the iodine and accelerator, will
not answer. For example: if a plate exposed to the vapor of iodine be
perfectly coated in sixteen seconds, and then exposed to an
accelerator, (not having iodine in its combination) receives its
coating in four seconds, it will be found that a proper proportionate
coating cannot be preserved by adopting, a proportion of time, but on
the contrary, the time will diminish; for exposure over the
accelerator, as in the above example, if it be desired to coat the
plate with twice as much iodine as in the above example, the time would
be, over iodine thirty-two seconds, and over the accelerator (to
possess a proper proportion) from six to seven seconds. Hence it is
that many inexperienced operators, when wishing to vary their usual
manner of coating, fail in producing a favorable result. They coat
calculating a proportion of time when they should not.

Dry Quick, No. 2.--Bromide of Lime and Magnesia.--To one quart of
hydrate of lime add one quart of magnesia, and mix them well together;
add bromine same as in preparing bromide of lime; coat the same as over
dry quick No. 1. This combination produces very uniform results, and
is worked with much success by beginners.

Chloro-Bromide of Lime.--To the bromide of lime add chloride of bromine
until the mixture becomes a pale yellow color, resembling sulphur. It
should be shook well, and enough of the chloride of bromine added to
bring the compound to a deep blood red color.

Use.--Coat over the iodine to a pink color, and then over the above to
a red, or just changing the color. It should be remembered that
accelerators containing chlorine do not admit of a great change of
color of coating on the plate.

Iodide of Starch.--This mixture can be employed for coating over in
warm weather, and prevent the flashing resulting at high temperatures.
It may be used the same as the iodide alone.

To six ounces of finely pulverized starch, add one fourth ounce of dry
iodine.

Use.--Same as the dry iodine alone.

The same combination may be made with lime, magnesia and other
substances.

Concentrated Solution of Iodine for First Coating.--It may appear
st