The ferrotype and how to make it - The Grian Press

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THE FEliUOTYPE.
evenly over the whole surface of the plate, with
out allowing it to rest at any part until the whole
is covered ; and for that purpose the plate should
be held so as to incline downward, and always
away from tlie holder. After the whole surface
shall have been covered, the solution should be
caused to flow backward and forward, by gently
rocking the plate, taking care not to allow any
of the solution to run off, either when pouring on
or afterward, until the process is complete.
The solution will hardly have covered the
plate before an image will begin to be developed,
at first slowly, then quicker and more plainly it
will appear, until in a short time the perfect
image will stand out boldly, when the develop-
ment is complete.
It is the process of development, and the chem-
ical and other changes which take place under
the action of the developing solution, which it is
desired to explain and make clear to the intelli-
gence of the reader.
First, then, we will try to explain the chemical
action which takes place in the sensitized collodion
film, when exposed in the camera. The
collodion plate, upon being taken from the silver
} ath, has received in and on its surface a deposit,
more or less dense, of iodide of silver, which,
upon being exposed in the camera to the action of
light reflected from an inanimate object or from a
person sitting for a portrait, is converted to a
sub-iodide by the loss of oxygen, chlorine, etc.;