the sensitive plates were always timed
exactly right. Correct exposure, however, is the exception rather than
the rule of amateur photography. To get good negatives, therefore, the
amateur must learn to distinguish between a correct and incorrect
exposure of the plate, and how to treat it, if incorrectly exposed, in
order to preserve the image which is impressed on it.

Over-exposure is the most common fault of the beginner in photography. A
properly exposed plate grows into a negative step by step, until the
whole image, with all its delicate gradations of lights and shadows, is
fully developed. An over-exposed plate acts in a very different manner.
When placed in the developer, instead of the high lights first appearing
and the objects coming out gradually, the whole image comes out almost
at once--"flashes up" is the technical and really appropriate term. If
the plate is left in the developer, the image will fade away almost as
quickly as it came out, and the result will be a thin negative, from
which satisfactory prints cannot be made.

TREATMENT.

As soon as the image flashes up, showing that the plate has been
over-exposed, take it from the developer and place it in a dish of clean
water to stop development. Turn the developer from the tray and rinse
the tray. Mix up a weak solution of developer, or dilute this same
developer one-third with water. Add to this weak developer a few drops
of a solution of bromide of potassium, prepared with a quarter of an
ounce of bromide of potassium and five ounces of water. This solution
should be mixed and kept always ready for use. Label the bottle
"Restrainer." The bromide is called a restrainer, as it makes the
development of the image proceed more slowly.

Put the plate back in the tray, and turn the developer, to which the
bromide has been added, over it, rocking the plate gently. Watch the
development closely, and if the image still comes up too fast add a few
more drops of bromide. Unless the plate has been very much over-exposed,
by taking it from the developer and using the restrainer carefully, a
good negative can usually be obtained. If the plate has been too much
over-exposed, there is no way of saving it.

If one knows or thinks that a plate has been over-exposed, the plate
should not be put in a normal developer--that is, a developer which
would be used for a correctly exposed plate--but it should be put into
the weak developer to which bromide has been add