[Illustration: FIG. 26.--LEAF PRINT. BY T. GAFFIELD.]
Nothing can exceed the beauty of form and structure of the leaves of
different plants. Ruskin observes: "Leaves take all kinds of strange
shapes, as if to invite us to examine them. Star-shaped, heart-shaped,
spear-shaped, fretted, fringed, cleft, furrowed, serrated, sinuated;
in whirls, in tufts, in spires, in wreaths; endlessly expressive,
deceptive, fantastic, never the same, from footstalk to blossom, they
seem perpetually to tempt our watchfulness and take delight in
outstripping our wonder." Photography has placed in our hands a simple
method of preserving facsimiles of their ever varying shapes that will
last long after the leaf has died and crumbled to dust. Although the
discovery of the darkening action of silver chloride when exposed to
light was discovered by Scheele as far back as 1777, little was
apparently known of the possibilities attending the discovery until
1839, when Fox Talbot read a paper on "A Method of Photogenic
Drawing," in which he described various experiments that could be made
with paper coated with this substance, and showed many pictures of
leaves, ferns, and pieces of lace which he had obtained.
[Illustration: FIG. 27.--LEAF PRINT. BY T. GAFFIELD.]
The illustrations which we reproduce herewith are reproductions from
leaf prints made by Mr. Thomas Gaffield, who has made quite a study of
this fascinating pastime. In a little work entitled "Photographic Leaf
Prints," published in 1869, he describes his method. The leaves and
ferns are first selected and pressed between the leaves of a book.
They must not be dried, as in that state they do not so readily permit
the light to pass through and the delicate structure of the leaf would
not be reproduced. They should therefore only be pressed sufficiently
to allow the excess of moisture to be extracted. A sheet of glass is
put into the printing frame and the leaves artistically arranged. When
the arrangement is satisfactory the leaves are attached to the glass
with a little mucilage to prevent them from slipping out of their
places. A sheet of sensitive paper, albumen, gaslight, or platinum is
then inserted, the frame closed up and exposed to the light until a
very dark print is obtained. The time required in printing must be
found by practice; it will, of course, differ according to the
intensity of the light. It is a good plan to employ an actinometer to
judge the correct exposure. It is not possible to open the frame, as a
double or blurred picture would result. The halves should be exposed
sufficiently long to enable the light to penetrate through them and
give a distinct image of the veins and structure.
When the printing is completed the paper is removed and toned and
fixed in the usual manner. If platinotype or gaslight paper is used,
this, of course, requires development. The resulting picture gives us
a light impression of the leaves on a dark background, but if so
desired, the print thus obtained can be used as a negative. It can be
made transparent with wax or vaseline, and prints obtained from it
giving a dark image on a white ground. It is difficult to say which
picture is the more beautiful. We give illustrations of pictures of
both kinds. (Figs. 26 and 27.)
Naturally enough, the beauty of these pictures lies in the careful
selection and arrangement of the leaves. Those which are too thick
should not be used. Delicate ones, showing all the veins by
transmitted light, are the most suitable. They can be arranged
artistically, in any shape or form. We prefer, however, a life-like
arrangement to the construction of various shapes and designs.