d, prepared by the inhabitants of the western
islands, and the northern shores of Scotland and Ireland. It is
treated with water, which washes out all the soluble salts, and the
filtered solution is evaporated until nearly all the carbonate of soda
and other saline matters have crystallized out. The remaining liquor,
which contains the iodine, is mixed with successive portions of
sulphuric acid in a leaden retort, and after standing some days to
allow the sulphureted hydrogen, etc., to escape, peroxide of manganese
is added, and the whole gently heated. Iodine distills over in a
purple vapor, and is condensed in a receiver, or in a series of
two-necked globes.

Properties.--Iodine is solid at the ordinary temperature, presenting
the appearance of dark-grey or purple spangles, possessing a high
degree of metallic lustre. It somewhat resembles plumbago, with which
it is sometimes diluted, particularly when it is fine. Operators
should endeavor to secure the larger crystals. It melts at 224.6 deg.,
forming a brown or nearly black liquid. It boils at about 356 deg.,
and emits a very deep violet colored vapor. It gives off a very
appreciable vapor, sufficient for all purposes of forming the iodide of
silver on the daguerreotype plate, at a temperature of 45 deg. or even
lower. Iodine crystallizes readily. Every operator has found upon the
side of the jar in his coating-box, perfectly regular crystals,
deposited there by sublimation.

Water dissolves but a small proportion of iodine, requiring 7000 parts
of water to dissolve one of iodine, {85} or one grain to the gallon of
water. Alcohol and ether dissolve it freely, as does a solution of
nitrate or hydrochlorate of ammonia and of iodides.

The density of solid iodine is 4.95; that of its vapor 8.716. It
greatly resembles chlorine and bromine in its combinations, but its
affinities are weaker. It does not destroy the majority of organic
substances, and vegetable colors generally resist its action. It
combines with several organic substances, imparting to them peculiar
colors. It colors the skin brown, but the stain soon disappears.

Chloride of Iodine--Is formed by passing chlorine into a bottle
containing some iodine. This can be readily done by pouring one ounce
and a half of muriatic acid upon a quarter of an ounce of powdered
black oxide of manganese, and heat it gradually in a flask, to which is
adapted a bent glass tube. This tube must connect with