Great care and judgment will be required in the application of this vapor to the plate; if the plate remain over the vapor too long, the developed picture will have a faint and misty appearance; if not exposed long enough, the "high light" will be solarized.

I have great hope of the ultimate use of this process, as it is the only means yet discovered to be enabled to secure specimens of extremes of light and shade, yet producing harmony of effect; and I would call the attention of the profession to the fact, that a plate may be exposed to the action of light for any length of time (a thousand times longer than required to act for the lesser quantity of mercury to deposit itself, or that amount necessary to form a perfect specimen), and be restored by the application of any of the vapors above mentioned, remarking that for extremes for solarization, denser vapors will be required.

Much remains to be done with this discovery to the application of the Daguerreotype.
HUMPHREY'S JOURNAL OF THE DAGUERREOTYPE & PHOTOGRAPHIC ARTS.
The above-named publication is well known as the best and most valuable one devoted to the Photographic Science in this country.

Humphrey's Journal made its appearance November 1st, 1850, and consequently is the first and oldest serial offered to the Photographic world.
The art of producing Portraits and Landscapes by means of Light, has recently taken a new and enlivening impulse, which will in all probability lead to important and interesting results.

No practical Daguerreotypist, Photographer, or amateur, should be without the means at hand for securing all of the information upon this subject.