then placed between sheets of
bibulous paper. When dry the paper is highly transparent.

IV. APPLICATION OF PHOTOGENIC DRAWING.--This method of photogenic
drawing may be applied to useful purposes, such as the copying of
paintings on glass by the light thrown through them on the prepared
paper--Imitations of etchings, which may be accomplished by covering a
piece of glass with a thick coat of white oil paint; when dry, with the
point of a needle, lines or scratches are to be made through the white
lead ground, so as to lay the glass bare; then place the glass upon a
piece of prepared paper, and expose it to the light. Of course every
line will be represented beneath of a black color, and thus an
imitation etching will be produced. It is also applicable to the
delineation of microscopic objects, architecture, sculpture, landscapes
and external nature.

A novel application of this art has been recently suggested, which
would doubtless prove useful in very many instances. By rendering the
wood used for engravings sensitive to light, impressions may be at once
made thereon, without the aid of the artist's pencil. The preparation
of the wood is simply as follows:--Place its face or smooth side
downwards, in a plate containing twenty grains of common salt dissolved
in an ounce of water; here let it remain for five minutes, take it out
and dry it; then place it again face downwards in another plate
containing sixty grains of nitrate of silver to an ounce of water; here
let it rest one minute, when taken out and dried in the dark it will be
fit for use, and will become, on exposure to the light, of a fine brown
color. Should it be required more sensitive, it must be immersed in
each solution a second time, for a few seconds only. It will now be
very soon effected by a very diffused light.

This process may be useful to carvers and wood engravers not only to
those who cut the fine objects of artistical design, but still more to
those who cut patterns and blocks for lace, muslin, calico-printing,
paper hangings, etc., as by this means the errors, expense and time of
the draughtsman may be wholly saved, and in a minute or two the most
elaborate picture or design, or the most complicated machinery, be
delineated with the utmost truth and clearness.

CHAP. IX.

CALOTYPE AND CHRYSOTYPE.

The materials and apparatus necessary for the Calotype process are--

Two or Three Shallow Dishes, for holding distilled water,