. Having spread a piece of silver leaf on a pane of glass,
and thrown a particle of iodine upon it, I observed that coloured rings
formed themselves around the central particle, especially if the glass was
slightly warmed. The coloured rings I had no difficulty in attributing to
the formation of infinitely thin layers or strata of iodide of silver; but
a most unexpected phenomenon occurred when the silver plate was brought
into the light by placing it near a window. For then the coloured rings
shortly began to change their colours, and assumed other and quite unusual
tints, such as are never seen in the "colours of thin plates." For
instance, the part of the silver plate which at first shone with a pale
yellow colour, was changed to a dark olive green when brought into the
daylight. This change was not very rapid: it was much less rapid than the
changes of some of the sensitive papers which I had been in the habit of
employing, and therefore, after having admired the beauty of this new
phenomenon, I laid the specimens by, for a time, to see whether they would
preserve the same appearance, or would undergo any further alteration.

Such was the progress which I had made in this inquiry at the close of the
year 1838, when an event occurred in the scientific world, which in some
degree frustrated the hope with which I had pursued, during nearly five
years, this long and complicated, but interesting series of
experiments--the hope, namely, of being the first to announce to the world
the existence of the New Art--which has been since named Photography.

I allude, of course, to the publication in the mouth of January 1839, of
the great discovery of M. Daguerre, of the photographic process which he
has called the Daguerreotype. I need not speak of the sensation created
in all parts of the world by the first announcement of this splendid
discovery, or rather, of the fact of its having been made, (for the actual
method made use of was kept secret for many months longer). This great
and sudden celebrity was due to two causes: first, to the beauty of the
discovery itself: secondly, to the zeal and enthusiasm of Arago, whose
eloquence, animated by private friendship, delighted in extolling the
inventor of this new art, sometimes to the assembled science of the French
Academy, at other times to the less scientific judgment, but not less
eager patriotism, of the Chamber of Deputies.

But, having brought this brief notice of the