It has long, since been known to operators, that if a plate be exposed to light after being coated, unless it be again coated, a clear and distinct picture could not be obtained upon the same plate without first repolishing and recoating the same, care being taken that no light fall upon the prepared surface. To prevent solarization, coat a plate as usual, expose to the action of light any required time (according to circumstances), say from quarter to one half more time than would be required in the ordinary method of procedure;observe, before putting the plate in the mercury box, place it over the vapor of iodine, bromine, or chlorine, etc. (carefully excluding the light), for a very brief period, great care being required to have the selected vapor very much diluted with air, in order to success.
Many experiments will be required ere arriving at satisfactory results.
Specimens now unknown to general operators, for harmony of effect, have been, and may again be produced by the method pointed out above.
I have found the best general effect, and the most certain result to follow from the use of the vapor of chlorine--but this requires more than ordinary care. I would, therefore, recommend the use of iodine. Thus: to a few grains of iodine, add an ounce of warm water (which will become tinged with iodine); when cold, to half a pint of pure water in a new and clean coating box, put, of the above, fifty drops; stir and mix well this small quantity of iodine in with the water; in ten minutes this box will be ready for use.
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. Each should be ready to receive and apply the improvements as they may be developed.
In order to accomplish this, it is a matter of great importance to the Practitioner or Experimenter that he should have a reliable medium through which he can obtain information.
In what source can the inquirer better place his confidence than in a regular Journal, whose editor is literally a practical person, and familiar with the manipulations necessary for producing Portraits upon "Daguerreotype Plates," and upon glass and paper?
Such is the conductor of Humphrey's Journal.
This Journal is published once every two weeks, and contains all the improvements relating to the Art, and is the only American Journal whose editor is practically acquainted with the process for producing Daguerreotypes, Ambrotypes, and Photographs.
The first No. of Vol. X. is dated May 1st, 1858. The terms (Two Dollars per annum) are trifling compared with the vast amount of information furnished.
AMBROTYPES.--Humphrey's Journal contains everything novel which appears upon this subject, and has already presented more new, important, and original matter than can be found in any other place.
Many are the letters we have received during the term of the last volume, in which the writer has stated that a single number of Humphrey's Journal has contained information of more value to him than "several times the amount paid for the entire volume."Our resources have grown up around us, and our facilities for procuring, as well as distributing, all such facts and improvements as will benefit as well as instruct all who have the progress of the Art at heart, are as ample as they can well be made.
The future volumes will be abundantly furnished with original writings from persons of standing in the scientific world;and the practical Photographer will here find a full account of such improvements as may from time to time develop themselves.
From the editor's long practical experience in the Heliographic Science, he will be enabled to present the subject in a plain, clear, and concise manner.
Read what the Editors say of Humphrey's Journal:--"We have received a copy of a valuable Journal (Humphrey's) published in New York, which has reached the 18th number of Vol. VI.....We now have the pleasure of quoting from our trans-atlantic coadjutor."--Liverpool Photographic Jour.
"Humphrey's Journal is practical as well as scientific in character."--American Journal of Science and Arts.
"It treats the subject knowingly and with force."--New York Tribune.
"It is both a popular and interesting publication."--Mechanics' Magazine.
"It is highly useful to all who practice 'shadow catching.'"--Ohio State Journal.
