using with the red bulb. Wait a few minutes until your eyes become accustomed
to the darkness. Have your eyedropper,glass rod, and silver bromide ready.
While the gelatin in the pot is still warm enough to flow like a liquid, dissolve
2 teaspoonfuls of silver bromide in it and stir. Hold oneofthe glass plates
between your fingers by the edges to prevent any finger marks. Carefully cover
the upper surface with gelatin bydistributingit with the eyedropperand then
tipping the plate in different directions until one whole surface is evenly covered.
Put this plate aside to dry on the aluminum foil, gelatin side up. Repeat this
procedurewith all the glass plates.
Take one ofyour pieces of blackconstructionpaper and fold it in half.
When a gelatin plate is completely solid and dry, place it between the folded
halves. Fold the paper looselyaroundthe plate on the three open sides, sothat
the plate is completely sealed. Secure these folds with paper clips. Do the same
with all the gelatin-covered plates. Do not squeeze or press the plates after
enclosing them in the paper or you will disturb the gelatin coating. Stack them
loosely, side by side and on edge, between the book ends. You will need these
plates, which are now covered by a light-sensitive, gelatinous film, for the next
experiment.