PHOTOGRAPHIC NOTES AND QUERIES.
Sir W. Newton's Process.—Having been requested by several friends to give them a statement of my mode of proceeding with reference to the calotypic art, and as I am of opinion that we ought to assist each other as much as possible in the pursuit of this important branch of photography, I beg therefore to offer the following for insertion in your "N. & Q.," if you should deem them worth your acceptance.
To iodize the Paper.—1st. Brush your paper over with muriate of barytes (half an ounce, dissolved in nearly a wine-bottle of distilled water): lay it flat to dry. 2nd. Dissolve sixty grains of nitrate of silver in about an ounce of distilled water. Ditto sixty grains of iodide of potassium in another bottle with the like quantity of water. Mix them together and shake well: let it subside: pour off the water, and then add hot water: shake it well: let subside: pour off the water, and then add three ounces of distilled water, and afterwards as much iodide of potassium as will redissolve the iodide of silver.
Brush your previously prepared paper well with this, and let dry; then place them in water, one by one, for about one hour and a half or two hours, constantly agitating the water. As many as a dozen pieces may be put into the water, one after the other, taking care that there are no air-bubbles: take them out, and pin to the edge of a board at one corner.
When dry they will be ready for exciting for the camera by the following process:
(These are supposed to be in six 1-ounce bottles with glass stoppers.)
| 1. 1 drachm of No. 4., 6 drachms of distilled water. | 2. 20 min. of No. 3., 6 drachms of distilled water. | 3. A saturated solution of gallic acid. | |
| 4. 25 grains of nitrate of silver to half an ounce of water. Add 45 minims of glacial acetic acid. | 5. 2 drachms of No. 4., 6 drs. of water. | 6. Equal parts of Nos. 1. and 2. N.B.—This must be mixed just before using, and the bottle cleaned afterwards. | |
To excite for the Camera.—Mix equal parts of Nos. 1. and 2., and with a glass rod excite the iodized paper and blot off; and it may be put in the slide at once, or the number you require may be excited, and put into a blotting paper book, one between each leaf, and allowed to remain until required to be placed in the slide.
Time of Exposure.—The time varies from three minutes to a quarter of an hour, according to the nature of the subject and the power of the sun; but five minutes is generally the proper time.
To bring out.—Bring out with No. 3., and when the subject begins to appear, add No. 5.; and when sufficiently developed hold it up, and pour water upon it; and then put it into hyposulphite of soda to fix it, for about half an hour
or more, and then into water: this is merely to fix it for the after process at your leisure.
To clean the Negative.—Get a zinc tray about three or four inches deep, with another tray to fit in at the top, about one inch deep; fill the lower tray with boiling water, so that the upper tray may touch the water; put your solution of hyposulphite of soda, not strong, in the upper tray, and then your negatives one by one, watching them with care until the iodine is removed; then put them in hot water, containing a small piece of common soda (the size of a nutmeg to about two quarts of water), for about ten minutes; pour off the dirty water, and then add more hot water, shaking them gently for a short time; pour off the water again, and then add fresh hot water, and let it remain until it is cold, after which take them out CAREFULLY, one by one, and put them in clean cold water for an hour or two; then take them all out together, and hold up to drain for a short time, and then put them between three or four thicknesses of linen, and press as much of the water out as you can; then carefully (for now all the size is removed) lay them out flat upon linen to dry.
Mode of Waxing the Negatives.—Melt the pure white wax over a lamp of moderate heat, just merely to keep it in a liquid state; then fill the same deep tray as above described with boiling water, and with another similar to the upper one before described (which must be kept for this purpose only); put a clean piece of blotting-paper in this tray, and lay your negative face downwards, and with a soft flat hog's hair-brush, about an inch wide, dip it into the liquid wax, and brush the negative over, when it will be immediately transparent, and it can be done so that there is very little redundant wax, after which it may be put between two or three thicknesses of blotting-paper and ironed, if necessary, which, however, should not be very hot, when it is ready to take positives from.
Positives on Negative Paper.—Take one part of the iodide of silver before described, and add two parts of water; then add as much iodide of potassium as will redissolve it. Brush your paper with the foregoing, let dry, put into water, and proceed, in all respects, as above described for the negatives.
Excite for Positives.—Excite with No. 1.; blot off: lay it in your press, place the negative face downwards: expose to the light from ten seconds to half a minute, or more, according to the light (not in the sun), and bring out with No. 3.; and when it is nearly developed add No. 1.; then take it up and pour water upon it, and then place it in hyposulphite of soda (cold) until the iodine is removed; after which put it into allum water, about half a teaspoonful of powdered allum in two quarts of water; this will readily remove the hyposulphite, and also fix the positive more particularly; it will also take away any impurities which there may be in the paper, after which put it into clean cold water, and change two or three times.
I have been thus particular in describing the process which I have adopted, more especially for beginners; and with great cleanliness and care in each process, and especially in keeping all the bottles with the chemicals free from dirt of every kind, the foregoing will lead to favourable results.
W. J. Newton.
I have been making some experiments in preparing the iodized paper in the following manner, more especially in consideration of the present price of iodide of potassium:—60 grains of nitrate of silver; 60 ditto of iodide of potassium, cleaned and prepared as before described, by the addition of three ounces of water,—that is 3 oz. altogether; 60 grains of cyanide of potassium; add a little of this at a time, and shake it up; and I generally find that this quantity is sufficient to redissolve the 60 grains of iodide of silver. Brush the paper over with the above, and when the wet surface disappears, dip it into cold water containing one drachm of dilute sulphuric acid to one quart of water; and then into water for half an hour, changing the water once: pin up to dry. I have not had an opportunity of trying this for negatives, but I have taken some good positives with the paper so prepared.
N.B.—I find that if the paper is allowed to dry with the cyanide of potassium, or that it is allowed to remain in the dilute sulphuric acid water too long, it weakens the paper so much as to be very absorbent. I would therefore wish to know from any of your correspondents whether this arises from taking away the size, or injuring the fibres of the paper? and, if so, whether a paper prepared with starch, instead of size, would be better? as it appears to me that this mode of iodizing might be an improvement. At all events, it is an enormous saving of iodide of potassium; as, for instance, to redissolve the 60 grains, it would take 1½ oz. of iodide of potassium (about four shillings); whereas 60 grains of cyanide would not cost more than one penny or twopence.
W. J. N.
Collodion Film on Copper Plates.—Would any of your correspondents kindly describe the manner in which the collodion film may be transferred to prepared copper plates?
It was noticed by your correspondent H. W. D. in Vol. vi., p. 470.
J. M. S.
Treatment of the Paper Positive after fixing.—1. Is it absolutely necessary for the preservation of the picture, that the size should be wholly removed from the paper? It seems to me that the hot-water treatment materially injures the tone.
2. In re-sizing, what is the kind of size and degree of strength generally made use of, and mode of application? I have tried gelatine and isinglass size, of various degrees of strength, without satisfactory results.
3. Should the hot iron, used for improvement of tone, be applied previous to the picture being re-sized, or as a finishing operation? I find much difficulty from the liability of the paper to shrivel under it.
4. Is the glossy appearance, observed in finished photographs, attained solely by use of the burnisher?
5. What is albumenized paper? used, I believe, by some in printing; and the mode of its preparation?
H. B. B.
P.S.—If I am not presuming too much upon your kindness, I should feel greatly indebted for information upon the above points, either privately or through the medium of "N. & Q.," according to the importance you may attach to them.