rface, the plate should be
perfectly cleaned. In this point, many who have tried the electrotype
process have failed, attributing their ill success to other than the
proper cause.

DAGUERREOTYPES WITHOUT MERCURY.

The following process possesses some interest, and is worthy a trial
from operators. M. Natterer, of Vienna, discovered a process for
obtaining proofs on iodized plates with the chloride of sulphur,
without the use of mercury. A plate of silver is iodized in the usual
manner, and then placed on the top of a vessel six or eight inches
high, having at the bottom, in a small cup, a few drops of chloride of
sulphur; it should remain exposed to the action of the vapor until the
sombre yellow color is changed to a red, after which it is brought to a
focus in the camera, where it is exposed to the light in the camera,
for about the time necessary to produce an ordinary daguerreotype. The
plate is then taken out and examined in the camera by the light of a
candle. It often occurs that no trace of the image is as yet
perceptible, but if the plate is heated by placing over a spirit lamp
the unprepared side, or if left for some time in the dark, or, lastly,
if exposed only a few seconds to a weak, dimmed light, the positive
picture then appears with all its shades. Of these three modes of
bringing out the image, the second is superior to the others.

MANAGEMENT OF CHEMICALS.

It is necessary, first of all, to know that you have a chemical which
is capable of producing good results when in skillful hands. For this
reason it is best to prepare your own quick, after some formula which
is known to be good. Those quick-stuffs which contain chloride of
iodine are noted for their depth of tone while they probably operate
with less uniformity than those which are destitute of it. For
operating under ordinary circumstances, especially with an inferior
light, probably no accelerator is more quick and sure than Wolcott's.
It also produces a very fine, white pleasing picture, though lacking
that depth of impression so much to be desired. The dry quick operates
with surety, and its use is simple and easy, producing an impression
much like Wolcott's. For those having a good and permanent light,
however, we would recommend a chemical giving more body to the
impression.

There is a class of accelerators called sensitives, claiming to work in
from three to ten seconds, which, however, will be found very little,
if