PHOTOGRAPHIC NOTES AND QUERIES.
The Albumen Process.—In answer to Mr. Lawrence's Queries regarding the albumen process (in Vol. vii., p. 116.), I think I can supply him with the information he requires.
The albumen should be placed in a cup, or some wide-mouthed vessel, and, after carefully removing from its surface every trace of air-bubbles, it is to be poured carefully on the plate, and after being flooded over the surface of it, the plate being tilted on one side, the greater portion of the albumen may be run off into the cup again. The plate must not be held sideways, however, for more than an instant; and it must be brought as soon as possible into the horizontal position, face downwards, between the points of the wire support, as used by Messrs. Ross and Thompson; and being held by the cord attached to the wire support, it must be given a slow rotary motion. The rate at which to cause it to rotate must be a matter of experience, but must be such as to keep the surface of albumen even, and neither to let it settle in the centre, nor to leave that and pass completely to the edges; neither must too much of it be allowed to flow off, as then the coating will not be thick enough. The best plan is to fix on the wire support at the corner of the plate, and then pour on the albumen, and then no time need be lost between pouring off and giving the rotary motion. The albumen will keep some time in a bottle; but as soon as it begins to get curdy and opalescent, it begins to lose in sensitiveness. The plate, if well prepared, will remain sensitive and in good order for two days at least, and being kept in a dry and cool place is a great assistance to its preservation. The addition of about five drops of saturated solution of bromide of potassium to every ounce of previously-iodized albumen causes great depth and brilliancy in the negative. The same sensitive bath answers over and over again, as with collodion. The time of exposure cannot be specified, as that varies almost indefinitely from ten minutes to an hour and a half.
In regard to obtaining a greater sensitiveness, the addition of starch size in the place of the water to the albumen appears to increase it, and certainly gives great improvement in depth of the blacks. A very good way of beating up the albumen is as follows:—Take a round stick, and having cut several slits in it, from the bottom half-way up it, insert into these several pieces of quill, so that they may project on each side of the stick to the length of about half an inch or a little more, and tie up the bottom of the stick with some string wound round it to keep the quills in place. Take then the albumen, iodized as directed by Thornthwaite or any other successful manipulator, and place it in a tall cylindrical glass vessel; and taking the whisk as above prepared between the palms of the hands, roll it backwards and forwards, keeping the part armed with the quills immersed in the albumen. This is the most effective method I know, and much less tiring than the old method with the common whisk.
In answer to another Querist, I have only to reply that the black tints in the French positives are due to the presence of starch, used as a size for the paper. I have lately succeeded in producing several very beautiful and brilliant effects of this kind by passing the paper—French or English, it does not much matter which—first over a size of starch, and next (after being dried) over a combination of albumen and thin starch size, composed of equal parts of each, to which, according to the process of M. Le Gray, may be added one-fifth of a saturated solution of chloride of ammonium. This is only an improvement in the process as described by M. Le Gray, and the rest of the process will be found in his own book, or in Thornthwaite's Guide.
F. M. L.
Torquay.
Queries on Mr. Weld Taylor's Process.—I hope Mr. Weld Taylor will not withhold (from those
who would most thankfully acknowledge the favour) an amended description of his paper process, embracing replies to the following Queries:
1. How strong should the cyanide solution be that is to be added "drop by drop;" and how much of it is likely to redissolve the precipitate formed by the first mixture?
2. Should the paper be brushed with, floated on, or immersed in the solution? If either of the latter, for how long a time; and what then?
3. How is the bath of nitrate of silver prepared, and the mode of applying it to the paper?
4. How much sulphuric acid is added to a given quantity of water, in which the paper is placed after removal from the exciting bath; and is it immersed or floated?
5. Is the paper, when removed from the water, to be partially dried with blotting-paper, and used in its damp state? or will it keep, and how long?
6. What is the probable time of exposure in the camera?
7. How is the picture developed? and, finally, how fixed?
John James.
Difficulties in the Wax-paper Process.—Can any of your photographic correspondents give me some hints regarding the following difficulties, which I (in common with many other amateurs) have met with in working according to Le Gray's wax-paper process?
The proportions I used were exactly those published by Le Gray, and the paper and other materials were of the description he recommends; but nearly every picture, on being placed in the gallic acid, was spoiled, by the appearance of numerous small black spots, all well defined on one and the same side, but comparatively undefined on the other. These may possibly have been owing to iron in the paper, and may therefore, perhaps, be obviated by following the method of Mr. Crookes. But I am anxious to learn if others have experienced these spots in their pictures, and to what they attribute them, as well as how they can best be prevented.
My second difficulty was in the want of intensity in the pictures, which completely prevented my obtaining even a tolerable impression from them. I tried many different times of exposure, and even after working long with Le Gray's slightly-different proportions, but always without success. The margin of the pictures, however, which had been exposed to the daylight, always became of the most intense black, after the picture had been developed.
But my third difficulty was the most annoying of all, because the constant source of failure, though in itself apparently the most easily obviated. It was the difficulty of keeping the dishes which contained the solution clean; the effect of this want of cleanliness being the marbling of the pictures whenever placed in the gallic acid and aceto-nitrate of silver. This is a difficulty I never before encountered, during half a dozen years' practice of photography (during which I used to be as successful as most of my brother amateurs); and though I tried every plan I could think of to insure cleanliness, such as washing the dishes with warm water, nitric and muriatic acids, &c., and afterwards wiping them thoroughly with clean cloths, still the mixture of gallic acid and aceto-nitrate of silver, for developing the picture, brought out some marblings or blotches on the dish, which were invariably communicated to the picture, even though it was only floated on the surface of the solution, and prevented, with the greatest care, from touching the bottom of the dish. Should the dishes be kept in the dark constantly?
Have any of your correspondents tried Le Gray's plan of filtering the nitrate of silver through animal charcoal; or do they find any occasion to filter at all? With me, the animal charcoal seemed to increase the sensibility greatly.
G. H.
Mr. Archer's Services to Photography.—In Vol. vii., p. 163., Mr. Horne seems very indignant at the idea that Mr. Archer taught him to take pictures, and says Mr. Archer's published account will not succeed. Now I know that Mr. Archer and myself did take pictures by his process as published. I also assert that neither Mr. Horne nor Mr. Fry made any collodion pictures before Mr. Archer published his account in The Chemist, and, with the ordinary camera, that process must be the one now to give any chance of success, for without washing the plate the collodion will not keep five or six hours without staining. But as that process was not sufficiently quick, Mr. Archer proposed to take the pictures in the bath itself; and I have one which I took in that way on the 16th of May, 1851.
Mr. Horne, I think ungenerously, wishes to detract from Mr. Archer's merit, and to exalt himself and Mr. Fry at Mr. Archer's expense. I have a letter of Mr. Fry's, dated March 23, 1852, in which he says, "I with much pleasure accord to Mr. Archer the credit he is fairly entitled to, of being the sole inventor of the collodion process." And another letter, wherein he says he "never sanctioned the insertion in any work of any article connected with the collodion process." I also know that Mr. Archer prepared collodion for Messrs. Horne; that Messrs. Horne advertised it as prepared by Mr. Archer; and that they were glad, when the thing was new, to avail themselves of Mr. Archer's assistance.
W. Brown.
Ewell.
Mr. Weld Taylor's Iodizing Process.—The process I generally adopt in iodizing paper by the
ammonio-nitrate of silver, I have found to be the most certain of all, and I here give a formula for the benefit of your readers. They will find it admirably adapted for any objects in the shade, or any not lit by the sun's rays; it also has an excellent quality, of not darkening by exposure in the camera, as most other papers do. I have taken negatives with it all the winter, even at Christmas. It is rather slow, but certain; and as your readers try it and improve it, I hope they will communicate the results.
It rests alone on the superior sensitive property the nitrate of silver possesses after being redissolved in ammonia, which every photographer must have experienced. And it has, I believe, in prospect, the dispensing with the crystals of nitrate of silver, and simply at last employing silver leaves, which will save a great expense to the operator. The first solution is, to the proportion of a wine-bottleful of water add three grains of pure tannin, well dissolved in filtered water. Upon this float every sheet of paper, taking care of bubbles when they are to be hung up to dry. Do a great number; they will be ready for the ultimate process. Make now a solution of nitrate of silver, twenty-six grains to the ounce: if three ounces are to be made, dissolve the nitrate in half an ounce of distilled water, and add liq. ammo. fortissimus till the precipitate is redissolved. Then fill up with two and a half ounces of distilled water. This is the formula of Mr. Alfred Taylor. With this solution pass over every sheet with a brush: it cannot be floated, as exposure to the air precipitates the silver. The iodizing solution is,—
| Iodide of potassium | 250 grs. |
| Fluoride of potassium | 20 grs. |
| Cyanide of potassium | 15 grs. |
| Muriate of soda | 30 grs. |
to a full half-pint of distilled water.
The success of the operation depends upon this point, that the latter solution must be laid over the first, before the first has entirely dried, or at that point when all appearance of wet is absorbed. Three sheets of paper may be washed over at a time; and as the corner where the solution runs to is apt to remain wet longer than the rest of the paper, the drip may be assisted off with a bit of blotting-paper. Also, before the second solution is dry, it is to be floated on water; but the same conditions must be strictly observed. When it has floated a short time, "it does not require so long a time as the acid process." It is, while wet, floated again upon a weak solution of free iodine for about half a minute; it may then be dried, and is ready for the sensitive solution. This last must be acid, and any of the approved formulæ will suit it; but the solution, whatever it is, must be allowed to dry before placing between the white glasses, nor on any account ought it to be touched with blotting-paper. The image is to be brought out with gallic acid and acetic acid, laid over with a brush, and requires no heat. It is of a very red colour generally, but that does not impair its effectiveness in taking the positive impression.
Weld Taylor.
7. Conduit Street West, Bayswater.
Sir W. Newton's Process.—Will Sir W. Newton be kind enough, through the mediums of "N. & Q.," to give the rationale of the action of the common soda and powdered allum mentioned in his process published in Vol. vii., p. 140. and why the soda is used for negatives and the allum for positives, both being produced on iodized paper?
Should these chemicals destroy the power of the hyposulphite of soda, I imagine the fading of positives will no longer be a matter of uneasiness; and I am sure all amateurs will be greatly indebted to him.
W. Adrian Delferier.
40. Sloane Square.