ictures instantly; a process of great importance
in securing the likeness of a child, or in taking views of animated
nature. Colonel Whitney informs me that he once took a view of the
steeple of the St. Louis Court House after sundown by this means, and
also secured the image of a man in the act of stepping into a store,
and before he had time to place his foot, raised for that purpose, on
the door step. Mr. Whitney is well known as the talented editor of the
Sunday Morning news.

New York, January 16, 1849.
Mr. H. H. SNELLING.

Dear Sir,--As you are about publishing a history of the Daguerreotype,
and request a description of my mode of taking pictures instantaneously
by the aid of galvanism, I comply with great pleasure.

In the year 1841, while practicing the art in St. Louis, Mo., I was at
times, during the summer, much troubled with the electric influence of
the atmosphere, especially on the approach of a thunder-storm. At such
times I found the coating of my plates much more sensitive than when
the atmosphere was comparatively free from the electric fluid, and the
effect was so irregular that no calculation could counteract the
difficulty. This satisfied me that electricity was in some measure an
important agent in the chemical process, and it occurred to me that the
element might be turned to advantage. I determined, therefore, to
enter on a series of experiments to test my theory. Finding it
impossible to obtain an electric machine, and unwilling to abandon the
examination, it occurred to me, that the galvanic influence might
answer the same purpose. I therefore proceeded to make a galvanic
battery in the following simple manner. I obtained a piece of zinc
about two inches long, one inch wide, and an eighth of an inch thick.
On this I soldered a narrow strip of copper, about six inches long, the
soldered end laid on one side of the zinc, and extending its whole
length. The battery was completed by placing the zinc in a glass
tumbler, two-thirds full of dilute sulphuric acid, strong enough to
produce a free action of the metals. The upper end of the copper slip
extending above the tumbler was sharpened to a point, and bent a little
over the glass.

The method of using, was thus:--After preparing the plate in the usual
manner and placing it in the camera, in such manner as to expose the
back of the plate to view, the battery was prepared by placing the zinc
in the acid, and as soon as the g