It is then to be well ironed with a smooth iron, heated so as barely not to injure the paper, placing it, for greater security against scorching, between clean smooth paper. If then the process have been successful, a perfectly black positive picture is at once developed.

At first it most commonly happens that the whole picture is sooty or dingy to such a degree that it is condemned as spoiled, but on keeping it between the leaves of a book, especially in a moist atmosphere, by extremely slow degrees this dinginess disappears, and the picture disengages itself with continually increasing sharpness and clearness, and acquires the exact effect of a copper-plate engraving on a paper more or less tinted with a pale yellow.

I ought to observe, that the best and most uniform specimens which I have procured have been on paper previously washed with certain preparations of uric acid, which is a very remarkable and powerful photographic element. The intensity of the original negative picture is no criterion of what may be expected in the positive. It is from the production by one and the same action of light, of either a positive or negative picture according to the subsequent manipulations, that I have designated the process, thus generally sketched out, by the term Amphitype,--a name suggested by Mr. Talbot, to whom I communicated this singular result; and to this process or cla.s.s of processes (which I cannot doubt when pursued will lead to some very beautiful results,) I propose to restrict the name in question, though it applies even more appropriately to the following exceedingly curious and remarkable one, in which silver is concerned:

At the last meeting I announced a mode of producing, by means of a solution of silver, in conjunction with ferro-tartaric acid, a dormant picture brought into a forcible negative impression by the breath or moist air. (See Cyanotype.) The solution then described, and which had at that time been prepared some weeks, I may here incidentally remark, has retained its limpidity and photogenic properties, quite unimpaired during the whole year since elapsed, and is now as sensitive as ever,--a property of no small value. Now, when a picture (for example an impression from an engraving) is taken on paper washed with this solution, it shows no sign of a picture on its back, whether that on its face is developed or not; but if, while the actinic influence is still fresh upon the face, (i.e., as soon as it is removed from the light), the back be exposed for a very few seconds to the sunshine, and then removed to a gloomy place, a positive picture, the exact complement of the negative one on the other side, though wanting of course in sharpness if the paper be thick, slowly and gradually makes its appearance there, and in half an hour or an hour acquires a considerable intensity. I ought to mention that the "ferro-tartaric acid" in question is prepared by precipitating the ferro-tartrate of ammonia (ammonia-tartrate of iron) by acetate of lead, and decomposing the precipitate by dilute sulphuric acid. When lead is used in the preparation of Amphitype paper, the parts upon which the light has acted are found to be in a very high degree rendered water proof.--Sir J. Herschel.

This process is a new invention of our countryman, J. A. Whipple, Esq., of Boston, and has been patented by M. A. Root, Esq., of Philadelphia.

It will be seen, however, from the previous pages of my work that Mr.

Root is mistaken in regard to his being the first improvement patented in this country, although it is unquestionably the first by an American. Of this improvement Mr. Root says:

VI. "CRAYON DAGUERREOTYPE."

"The improvement to which you refer is denominated "The Crayon Daguerreotype." This invention made by Mr. J. A. Whipple, is the only improvement in Daguerreotyping, I believe, for which Letters Patent for the United States were ever issued. The pictures produced by this process--which is of the simplest description imaginable--have the appearance and effect of very fine "Crayon Drawings," from which the improvement takes its name. Some of our most distinguished artists have given it their unqualified admiration. Among them, our Mezzotinto Engravers, especially John Sartain, Esq., who, from his rich embellishments to most of the leading Magazines and Annuals of the country, as well as from the celebrity of the superb Magazine which bears his name, is so well known and so well qualified to judge of its merits. As an auxiliary to the artist, in furnishing heads to the Magazines, or other works, it is invaluable; the great object which it accomplishes being to give a finer effect and more distinct expression to all the features--the whole power of the instrument being directed to, and confined to the head."

"The late hour at which this subject has been brought to our notice prevents so full a description as we would otherwise have been glad to furnish. The New England States have been disposed of; negotiations for any of the others can be made through M. A. Root, 140 Chestnut street, Philadelphia."

"A series of beautiful portraits are about being prepared by the "Crayton Process" for the express purpose of being placed on the exhibition at the "Art Union," when amateurs, artists, and the public generally will have an opportunity of witnessing its effect. We are especially gratified with this striking improvement, from the advantages which it promises to the Daguerrean art."

"It is admirably designed to excite a new interest on the subject through the community, and in this way--and from its tendency to render the art more generally useful, and to elevate and distinguish it--to make it to all a matter of more general importance."

"Yours respectfully, "M. A. ROOT."

In our second edition, we hope--with Mr. Root"s permission--to lay the whole process before the public, although our artists must bear in mind that Mr. Root"s patent secures to him the exclusive right of its application.

CHAP. XI.

ON THE PROBABILITY OF PRODUCING COLORED PICTURES BY THE SOLAR RADIATIONS--PHOTOGRAPHIC DEVIATIONS--LUNAR PICTURES--DRUMMOND LIGHT.

Having before noticed the fact that some advances had been made towards taking Daguerreotypes in color, by means of solar rays, and expressed the hope that the day was not far distant when this might be accomplished, I here subjoin Mr. Hunt"s remarks on this subject.

Mr. Biot, in 1840, speaking of Mr. Fox Talbot"s beautiful calotype pictures, considers as an illusion "the hope to reconcile, not only the intensity but the tints of the chemical impressions produced by radiations, with the colors of the object from which these radiations emanated." It is true that three years have pa.s.sed away, and we have not yet produced colored images; yet I am not inclined to consider the hope as entirely illusive.

It must be remembered that the color of bodies depends entirely upon the arrangement of their molecules. We have numerous very beautiful experiments in proof of this. The bi-niodide of mercury is a fine scarlet when precipitated. If this precipitate is heated between plates of gla.s.s, it is converted into crystals of a fine sulphur yellow, which remain of that color if undisturbed, but which becomes very speedily scarlet if touched with any pointed instrument. This very curious optical phenomena has been investigated by Mr. Talbot and by Mr. Warrington. Perfectly dry sulphate of copper is white; the slightest moisture turns it blue. Muriate of cobalt is of a pale pink color; a very slight heat, by removing a little moisture, changes it to a green. These are a few instances selected from many which might be given.

If we receive a prismatic spectrum on some papers, we have evidence that the molecular or chemical disturbance bears some relation to the color of each ray, or, in other words, that colored light so modifies the action of ENERGIA that the impression it makes is in proportion to the color of the light it accompanies, and hence there results a molecular arrangement capable of reflecting colors differently. Some instances have been given in which the rays impressed correspond with the colors of the luminous rays in a very remarkable manner.* One of the most decided cases is that of the paper prepared with the fluoride of soda and nitrate of silver. Sir John Herschel was, however, the first to obtain any good specimens of photographically impressed prismatic colorations.

* See Mr. Hunt"s "Researches on Light."

It was noticed by Daguerre that a red house gave a reddish image on his iodized silver plate in the camera obscura; and Mr. Talbot observed, very early in his researches, that the red of a colored print was copied of a red color, on paper spread with the chloride of silver.**

** In 1842, I had shown me a picture of a house in the Bowery, which had been repaired a few days previous, and in the wall a red brick left. This brick was brought out on the Daguerreotype plate of precisely the same color as the brick itself. The same artist also exhibited to me, the full length portrait of a gentleman who were a pair of pantaloons having a blue striped figure. This blue stripe was fully brought out, of the same color, in the picture.--AMER. ED.

"In 1840 I communicated to Sir John Herschel some very curious results obtained by the use of colored media, which he did me the honor of publishing in one of his memoirs on the subject from which I again copy it."

"A paper prepared with muriate of barytes and nitrate of silver, allowed to darken whilst wet in the sunshine to a chocolate color, was placed under a frame containing a red, a yellow, a green, and a blue gla.s.s. After a week"s exposure to diffused light, it became red under the red gla.s.s, a dirty yellow under the yellow gla.s.s, a dark green under the green, and a light olive under the blue.

"The above paper washed with a solution of salt of iodine, is very sensitive to light, and gives a beautiful picture. A picture thus taken was placed beneath the above gla.s.ses, and another beneath four flat bottles containing colored fluids. In a few days, under the red gla.s.s and fluid, the picture became a dark blue, under the yellow a light blue, under the green it remained unchanged, whilst under the blue it became a rose red, which in about three weeks changed into green. Many other experiments of a similar nature have been tried since that time with like results.

"In the summer of 1843, when engaged in some experiments on papers prepared according to the principles of Mr. Talbot"s calotype, I had placed in a camera obscura a paper prepared with the bromide of silver and gallic acid. The camera embraced a picture of a clear blue sky, stucco-fronted houses, and a green field. The paper was unavoidably exposed for a longer period than was intended--about fifteen minutes,--a very beautiful picture was impressed, which, when held between the eye and the light, exhibited a curious order of colors.

The sky was of a crimson hue, the houses of a slaty blue, and the green fields of a brick red tint. Surely these results appear to encourage the hope, that we may eventually arrive at a process by which external nature may be made to impress its images on prepared surfaces, in all the beauty of their native coloration."

PHOTOGRAPHIC DEVIATIONS.

Before taking leave of the subject of photogenic drawing, I must mention one or two facts, which may be of essential service to operators.

It has been observed by Daguerre, and others, in Europe, and probably by some of our own artists, that the sun two hours after it has pa.s.sed the meridian, is much less effective in the photographic process, than it is two hours previous to its having reached that point. This may depend upon an absorptive power of the air, which may reasonably be supposed to be more charged with vapor two hours before noon. The fuse of the hygrometer may possibly establish the truth or falsity of this supposition. The fact, however, of a better result being produced before noon being established, persons wishing their portraits taken, will see the advantage of obtaining an early sitting, if they wish good pictures. On the other hand, if the supposition above mentioned prove true, a too early sitting must be avoided.

If we take a considerable thickness of a dense purple fluid, as, for instance, a solution of the ammonia-sulphate of copper, we shall find that the quant.i.ty of light is considerably diminished, at least four-fifths of the luminous rays being absorbed, while the chemical rays permeate it with the greatest facility, and sensitive preparations are affected by its influence, notwithstanding the deficiency of light, nearly as powerfully as if exposed to the undecomposed sunbeams.

It was first imagined that under the brilliant sun and clear skies of the south, photographic pictures would be produced with much greater quickness than they could be in the atmosphere of Paris. It is found, however, that a much longer time is required. Even in the clear and beautiful light of the higher Alps, it has been proved that the production of the photographic picture requires many minutes more, even with the most sensitive preparations, than it does in London. It has also been found that under the brilliant light of Mexico, twenty minutes, and half an hour, are required to produce effects which in England would occupy but a minute; and travellers engaged in copying the antiquities of Yucatan have on several occasions abandoned the use of the photographic camera, and taken to their sketch books. Dr.

Draper* has observed a similar difference between the chemical action of light in New York and Virginia. This can be only explained by the supposition that the intensity of the light and heat of these climes interferes with the action of the ENERGIC rays on those sensitive preparations which are employed.

* I would here take occasion to remark that our country man, Dr.

Draper, is very frequently quoted by Mr. Hunt in his "Researches."

LUNAR PICTURES--DRUMMOND LIGHT.

The Roman Astronomers state that they have procured Daguerreotype impressions of the Nebula of the sword of Orion. Signor Rondini has a secret method of receiving photographic images on lithographic stone; on such a prepared stone they have succeeded in impressing an image of the Nebula and its stars; "and from that stone they have been enabled to take impressions on paper, unlimited in number, of singular beauty, and of perfect precision." Experiments have, however, proved that "no heating power exists in the moon"s rays, and that lunar light will not act chemically upon the iduret of silver."

It was at one time supposed that terrestrial or artificial light possessed no chemical rays, but this is incorrect--Mr. Brande discovered that although the concentrated light of the moon, or the light even of olefiant gas, however intense, had no effect on chloride of silver, or on a mixture of chloride and hydrogen, yet the light emitted by electerized charcoal blackens the salt. At the Royal Polytechnic Inst.i.tution pictures have been taken by means of sensitive paper acted upon by the Drummond Light; but it must of course be distinctly understood, that they are inferior to those taken by the light of the sun, or diffused daylight.

If our operators could manage to produce good pictures in this way they would put money in their pockets, as many who cannot find time during the day would resort to their rooms at night. I throw out the hint in hopes some one will make the experiment.

I have learned, since the above was written, that an operator in Boston succeeded a short time since in procuring very good pictures by the aid of the Drummond Light; but that the intensity of the light falling directly upon the sitter"s face caused great difficulty, and he abandoned it. This may, probably, be remedied by interposing a screen of very thin tissue paper tinged slightly of a bluish color.

CHAP. XII.

ON COLORING DAGUERREOTYPES.

Nearly, if not quite all the various colors used in painting may be made from the five primitive colors, black, white, blue, red and yellow, but for the Daguerrean artist it would be the best policy to obtain such as are required by their art already prepared. In a majority of cases, the following will be found sufficient, viz.

Carmine.

Prussian Blue.

White.

Chrome Yellow, Gamboge, Yellow Ochre; or all three.*

*Gamboge is best for drapery; Ochre for the face.

Light Red.

Indigo.

Burnt Sienna.

Bistre, or Burnt Umber.

© 2024 www.topnovel.cc