ordered with banking wax
and bitten-in with a solution of ferric chloride at 45 deg. Baume, or--

Ferric chloride, crystal 20 parts
Hydrochloric acid 1 part
Water 100 parts

The parts of the gelatine film the most acted on are impermeable, so to
say, and consequently do not allow the etching fluid to penetrate to the
copper; while those the least impressed are permeated according as to
their degree of insolation, Therefore, when the ferric chloride solution
is poured upon the film and carefelly brushed over with a soft brush, in a
few moments the image progressively appears, the deep blacks first, then
the half tints, and lastly the most delicate details, the whole requiring
but a few minutes. It is now that the etching action should be stopped by
washing under the tap. However, should by excess of exposure, or any
other cause, the details not appear within five or six minutes, the ferric
chloride should nevertheless be washed off, for then it may find its way
under the film and the plate would be spoiled. After washing the gelatine
is dissolved in a solution of potash, etc., when the image would be found
slightly engraved.

Should the image be in half-tints, it would be advisable to apply a grain
of rosin on the gelatine film just before etching. To engrave on steel
the operations are the same, but on its removal from the printing frame
the plate should be soaked with water renewed several times until the
bichromate is washed off. The film is then dried spontaneously and
afterwards flowed for about two minutes with the Solution A, then, this
being thrown away, with the Solution B, which is allowed to act for a
similar period.

A. Nitric acid, pure 120 parts
Silver nitrate 6 parts
Alcohol, 95 deg 50 parts
Water 75 parts
B. Nitric acid, pure 5 parts
Alcohol, 95 deg 40 parts
Water 60 parts

GRAPHOTYPY.

This process consists in converting a cliche in half tones into one in
lines, which can be directly printed on paper, or impressed, by means of
an ink transfer made as explained before, on a stone, or on a zinc or
copper plate for etching in relief, or in intaglio, according as the
cliche is negative or positive.

A cliche on gelatine, but preferably on a collodion film, is varnished
with a solution of yellow wax and bitumen in benzole and turpentine-oil:

Bitumen of Judaea 8 parts
Yellow