e establishments in this city, and the superiority of the
pictures produced by it was considered as an equivalent for the
additional time required to bring out the impressions.

Chlorine as an Accelerator.--I shall here refer to but a single
experiment in which I employed chlorine gas for coating the plate. I
was provided with a retort, the neck of which was fitted to the jar of
my coating-box, through a hole drilled for its reception. This was
fitted perfectly tight in my coating-box. I placed some pure undiluted
bromine water and the agents necessary for producing chlorine gas (in
small quantity) in the retort. The result was that my first experiment
produced an impression completely solarized in all its parts by an
exposure of four seconds of time, which would have required an exposure
of twenty seconds to produce a perfectly developed impression by the
usual process.

Another trial immediately produced one of the finest toned impressions
I ever saw, perfectly developed in one second of time.

My next two or three experiments proved total failures. I was unable
to produce even a sign of an impression. By accident my retort was
broken, and not being in a locality convenient to obtain another, my
experiments were necessarily suspended.

My attention was not called to this subject again for several years,
when I noticed an account of some similar experiments by F. A. P.
Barnard and Dr. W. H. Harrington, the latter of whom is now of the firm
of Dobyns & Harrington, of New Orleans.

From reading this article, I found my own difficulties explained. Too
much of the chlorine gas was present in my coating jar. I would like
to see some of our enterprising operators investigate this combination.

It is a singular fact, that the vapors of bromine and chlorine
combining upon the iodide of silver, produce a more sensitive coating
than when the two are combined in solution, as in chloride of bromine
solution. Those having Humphrey's Journal at hand, can refer to vol.
i. p. 142.

To use Bromine Water or other Accelerators in Hot Weather.--An
excellent plan for using bromine water is as follows:

Fill a two-ounce bottle quarter full of it, and then fill the bottle
with fine sand, which serves to preserve a low temperature; then place
the bottle in a porous cup, same as used in the battery; fill this also
with sand, and close the end with plaster of Paris. Place this in a
coating-box, and it will be found to act with