recoat over the first about one fourth as long as
first coating.

Gurneys American Compound.--Of this compound there are two
combinations, one for use, when the temperature of the atmosphere is
above 65 or 70 deg., and the other at a lower temperature. The first
is called No. 1, the second No. 2.

No. 1 is prepared by placing hydrate of lime in a bottle, say to three
quarts of the hydrate of lime, add one ounce of pulverized burnt alum,
and as much chloride of lime as can be put on a quarter of a dollar,
and from 15 to 30 grains of dry pulverized iodine, or enough to change
the color of the hydrate of lime, to the slightest possible tinge of
yellow. There had better be less than carry the color to a deeper
shade. The object of using the iodine is to form a compound with
bromine that is not so volatile as the bromine itself. No matter how
little iodine is combined with the bromine, the vapors possess their
relative proportion; hence, only enough iodine to prevent "flaring," or
as it is often termed a "scum-coating," is used. The iodine should be
thoroughly combined with the lime, which will take about one or two
days. Should add bromine the same as in bromide of lime, until the
compound assumes a light red color.

No. 2 is prepared in the same manner as No. 1, except the addition of
the iodine, which is omitted.

Use.--No. 1. Coat over the iodine to a bright yellow color, then over
the compound, No. 1, to red color, recoat over iodine, about one sixth
as long, as the time occupied in first coating.

No. 2. Coat over iodine same as above, except recoat over the iodine
about one fourth to one half as long as first coating.

Dry Quick, No. 1.--Bromide of Lime and Starch.--The following compound
forms an excellent accelerator, and is used by many. It is claimed for
this preparation, that it will hold the bromine longer than others
where starch is not employed. As regards this claim we do not think it
can be substantiated. Our experience in practice has led us to the
conclusion that there is no great difference as respects durability,
but there is some little difference as regards the tone of the
impressions produced by its use.

To one quart of hydrate of lime add one quart of finely pulverized
starch. To this mixture add bromine, until it assumes a deep yellow or
pink color.

Starch may be added to any of the dry mixtures.

Use.--Coat over the iodine to a deep yellow, then over this quick to a
red c