glass and the light traversing the
painting produced a kind of copy upon the prepared paper, those parts
in which the rays were least intercepted being of the darkest hues.
Here, however, terminated the experiment; for although both Mr.
Wedgwood and Sir Humphry Davey experimented carefully, for the purpose
of endeavoring to fix the drawings thus obtained, yet the object could
not be accomplished, and the whole ended in failure."

This, by their own showing, was the earliest attempt of the English
savans. But this much of the principle was known to the Alchemists at
an early date--although practically produced in another way--as the
following experiment, to be found in old books, amply proves.

"Dissolve chalk in aquafortis to the consistence of milk, and add to it
a strong solution of silver; keep this liquor in a glass bottle well
stopped; then cutting out from a piece of paper the letters you would
have appear, paste it on the decanter, and lay it in the sun's rays in
such a manner that the rays may pass through the spaces cut out of the
paper and fall on the surface of the liquor the part of the glass
through which the rays pass will be turned black, while that under the
paper remains white; but particular care must be observed that the
bottle be not moved during the operation."

Had not the alchemists been so intent upon the desire to discover the
far famed philosopher's stone, as to make them unmindful of the
accidental dawnings of more valuable discoveries, this little
experiment in chemistry might have induced them to prosecute a more
thorough search into the principle, and Photogenic art would not now,
as it is, be a new one.

It is even asserted that the Jugglers of India were for many ages in
possession of a secret by which they were enabled, in a brief space, to
copy the likeness of any individual by the action of light. This fact,
if fact it be, may account for the celebrated magic mirrors said to be
possessed by these jugglers, and probable cause of their power over the
people.

However, as early as 1556 the fact was established that a combination
of chloride and silver, called, from its appearance, horn silver, was
blackened by the sun's rays; and in the latter part of the last century
Mrs. Fulhame published an experiment by which a change of color was
effected in the chloride of gold by the agency of light; and gave it as
her opinion that words might be written in this way. These incidents
are co