e newly precipitated iodide in
the lighter portions and thus the negative picture is converted into a
positive one.

The calotype process has been applied to the art of printing, in
England, but it possesses no advantages whatever over the method, with
type, now so gloriously brought to perfection; and I can hardly think
it will ever be made of any utility. For the benefit of the curious,
however, I will give Mr. Talbot's method.

Some pages of letter-press are taken printed on one side only; and
waxed, to render them more transparent; the letters are then cut out
and sorted. To compose a new page lines are ruled on a sheet of white
paper, and the words are formed by fixing the seperate letters in their
proper order. The page being ready, a negative photograph is produced
from it, from which the requisite number of positive photogenic copies
may be obtained.

Another method, which requires the use of the camera, consists in
employing large letters painted on rectangular pieces of wood, colored
white. These are arranged in lines on a tablet or board, by slipping
them into grooves which keep them steady and upright, thus forming a
page on an enlarged scale. It is now placed before a camera, and a
reduced image of it of the required size is thrown upon the sensitive
paper. The adjustments must be kept invariable, so that the
consecutive pages may not vary from one another in the size of the
type. Mr. Talbot has patented his process, but what benefit he expects
to derive from it, I am at a loss to determine.

Enlarged copies of calotype or Daguerreotype portraits may be obtained
by throwing magnified images of them, by means of lenses, upon calotype
paper.

THE CHRYSOTYPE.

A modification of Mr. Talbot's process, to which the name of Chrysotype
was given by its discoverer, Sir John Herschel, was communicated in
June 1843 to the Royal Society, by that distinguished philosopher.
This modification would appear to unite the simplicity of photography
with all the distinctness and clearness of calotype. This preparation
is as follows.

The paper is to be washed in a solution of ammonio-citrate of iron; it
must then be dried, and subsequently brushed over with a solution of
the ferro-sesquicyanuret of potassium. This paper, when dried in a
perfectly dark room, is ready for use in the same manner as if
otherwise prepared, the image being subsequently brought out by any
neutral solution of gold. Such was the firs