for the chemicals.

d. If by accident (we would not advise a trial to any extent
of this), you should inhale a quantity of the vapor of bromine,
immediately inhale the vapor of aqua ammonia, as this
neutralizes the dangerous effect of the bromine vapor.
every operator should be provided with a bottle of ammonia,
as a little sprinkled about the chemical room soon disinfects
it of all iodine or bromine vapor, and also tends to facilitate
the operation in the camera.


IODINE.

History of Iodine.--This is one of the simple chemical bodies
which was discovered in 1812 by M. Courtois, of Paris, a manufacturer
of saltpetre, who found it in the mother-water of that salt.
Its properties were first studied into by M. Gay Lussac.
It partakes much of the nature of chlorine and bromine.
Its affinity for other substances is so powerful as to prevent
it from existing in an isolated state. It occurs combined with
potassium and sodium in many mineral waters, such as the brine
spring of Ashby-de-la-Zouche, and other strongly saline springs.
This combination exists sparingly in sea-water, abundantly in many
species of fucus or sea-weed, and in the kelp made from them.
It is an ingredient in the Salt Licks, saline, and brine springs
of this country, especially of those in the valley of the Mississippi.
It is sparingly found in fresh-water plants, as well also in coal,
and in combination with numerous other bodies.