Its attraction for basis is such that it separates or expels all
other acids, more or less perfectly, from their combinations.
Its affinity for water is such that it rapidly absorbs it from
the atmosphere, and when mixed with water much heat is evolved.
It acts energetically upon animal and vegetable substances,
and is a poisonous, dangerous substance to get on the skin.
It is a powerful oxidizing agent; hence its use in the galvanic battery,
for which purpose it is mostly used by the Daguerreotypist.
The fumes of this being so much more offensive than nitric acid,
the latter is sometimes used. It is also employed in some of
the more sensitive accelerators.


ACCELERATING SUBSTANCES.

Remarks on the Accelerating substances Used in the Daguerreotype.--
I have now arrived at a point in this work, where the eye of
the Daguerreotype public will intently search for something new.
This search will prove in vain, at least so far as regards
those who have enjoyed and embraced the opportunities for studying
the principles of our art. Every experienced operator has in a degree
become familiar with the mechanical uses of all the agents employed,
while I fear but few understand the properties, and laws governing
those properties, which are so indispensable to produce an image
impressed upon the silver surface.

There are three substances which form the bases for
producing a Daguerreotype; silver, iodine and bromine.
Each forms a separate body which is indispensable to the
operators success as the art is now practiced in America.