PHOTOGRAPHIC NOTES AND QUERIES.
Originator of the Collodion Process.—All those who take any interest in photography must agree with your correspondent G. C. that M. Le Gray is a talented man, and has done much for photography. G. C. has given a very good translation of M. Le Gray's last published work, p. 89., which work I have: but I must take leave to observe, that it is no contradiction whatever to my statement. The translations to which M. Le Gray alludes, of 1850, appeared in Willat's publication, from which I gave him the credit of having first suggested the use of collodion in photography. The subject is there dismissed in three or four lines.
M. Le Gray gave no directions whatever for its application to glass in his work published in July 1851, wherein he alludes to it only as an "encallage" for paper, classing it with amidou, the resins, &c., which he recommends in a similar manner.
I had, four months previous to this, published the process in detail in the Chemist. I never asserted that he had not tried experiments with collodion in 1849; but he did not give the public the advantage of following him: and I again repeat that the first time M. Le Gray published the collodion process was in September, 1852,—a year and a half after my publication, and when it had become much used.
It is obvious that if M. Le Gray had been in possession of any detailed process with collodion on glass in 1850, he would not have omitted to publish it in his work dated July, 1851.
F. Scott Archer.
105. Great Russell Street, Bloomsbury.
G. C., claiming for Le Gray the merit of the first use of collodion upon glass, states that a pamphlet upon the subject was published in 1850, and which was translated into English at the same time. Will he oblige me by stating who published this pamphlet, or where it may be obtained? I have heard this statement before, and have used every endeavour to obtain a sight of the publication, but without success. Were the facts as stated by your correspondent, it would deprive Mr. Archer undoubtedly of the merit which he claims; but from all I have been able to learn, Le Gray mentioned collodion as a mere agent for obtaining a smooth surface to paper, or other substance, having no idea of making it the sole sensitive substance to be employed. I have been informed that in Vienna, early in 1850, collodion was tried upon glass by being first immersed in a bath of iodide of potassium; and it was afterwards placed in a second bath of nitrate of silver. These experiments had very limited success, and were never published, and certainly were unknown to Mr. Archer.
H. W. D.
Mr. Weld Taylor's Process.—In your 167th Number (Vol. vii., p. 48.) is a communication from Weld Taylor on photographic manipulation, which, in its present form, is perfectly unintelligible. At p. 48. he says: "Twenty grains of nitrate of silver in half an ounce of water is to have half an ounce of solution of iodide of potassium of fifty grains to the ounce added." Now this is unnecessarily mystifying. Why not say: "Take equal quantities of a forty-grain solution of nitrate of silver, and of a fifty-grain solution of iodide of potassium;" though, in fact, an equal strength would do as well, and be quite as, if not more, economical.
In the next place, he directs that cyanide of potassium should be added drop by drop, &c. It
is to be presumed that he means a solution of this salt, which is a solid substance as usually sold.
What follows is so exceedingly droll, that I can do nothing more than guess at the meaning. How one solution is to be floated on another, and then, after a bath of nitrate of silver, is to be ready for the camera, surpasses my comprehension.
Also, further on, he alludes to iodizing with the ammonio-nitrate (I presume of silver). What does he mean?
Geo. Shadbolt.
Dr. Diamond's Services to Photography.—Sir, We, the undersigned amateurs of Photography in the city of Norwich, shall be obliged if you will (privately, or otherwise, at your own discretion) convey to Dr. Diamond our grateful thanks for the frankness and liberality with which he has published the valuable results of his experiments in the pages of "N. & Q." We have profited largely by Dr. Diamond's instructions, and beg to express our conviction that he is entitled to the gratitude of every lover of the Art.
We are, Sir,
Your obedient servants,
T. Lawson Sisson, Clk., (Edingthorpe Rectory).
Thos. D. Eaton.
John Crosse Koope.
James Howes.
T.G. Bayfield.
G. Brownfield.
Henry Pulley.
W. Bransby Francis.
J. Blowers (Cossey).
Benj. Russell.
[Agreeing, as we do most entirely, with the Photographers of Norwich in their estimate of the skill and perseverance exhibited by Dr. Diamond in simplifying the collodion and paper processes, and of his liberality in making known the results of his experiments, we have great pleasure in giving publicity to this recognition of the services rendered by Dr. Diamond to this important Art.]
Simplification of the Wax-paper Process.—At a late meeting of the Chemical Discussion Society, Mr. J. How read the following paper on this subject:—
"The easiest way of waxing the paper is to take an iron (those termed 'box-irons' are the cleanest and best for the purpose) moderately hot, in the one hand, and to pass it over the paper from side to side, following closely after it with a piece of white wax, held in the other hand, until the whole surface has been covered. By thus heating the paper, it readily imbibes the wax, and becomes rapidly saturated with it. The first sheet being finished, I place two more sheets of plain paper upon it, and repeat the operation upon the top one (the intermediate piece serving to absorb any excess of wax that may remain), and so on, sheet after sheet, until the number required is waxed.
"The sheets, which now form a compact mass, are separated by passing the iron, moderately heated, over them; then placed between folds of bibulous paper, and submitted to a further application of heat by the means just described, so as to remove all the superfluous wax from the surface, and render them perfectly transparent—most essential points to be attended to in order to obtain fine negative proofs.
"I will now endeavour to describe the method of preparing the iodizing solution.
"Instead of being at the trouble of boiling rice, preparing isinglass, adding sugar of milk and the whites of eggs, &c., I simply take some milk quite fresh, say that milked the same day, and add to it, drop by drop, glacial acetic acid, in about the proportion of one, or one and a half drachm, fluid measure, to the quart, which will separate the caseine, keeping the mixture well stirred with a glass rod all the time; I then boil it in a porcelain vessel to throw down the remaining caseine not previously coagulated, and also to drive off as much as possible of the superfluous acid it may contain. Of course any other acid would precipitate the caseine; still I give the preference to the acetic from the fact that it does not affect the after-process of rendering the paper sensitive, that acid entering into the composition of the sensitive solution.
"After boiling for five or ten minutes, the liquid should be allowed to cool, and then be strained through a hair sieve or a piece of muslin, to collect the caseine: when quite cold, the chemicals are to be added.
"The proportions I have found to yield the best results are those recommended by Vicomte Veguz, which I have somewhat modified, both as regard quantities and the number of chemicals employed. They are as follow:
| 385 | grains | of iodide of potassium. |
| 60 | " | of bromide. |
| 30 | " | of cyanide. |
| 20 | " | of fluoride. |
| 10 | " | of chloride of sodium in crystals. |
| 1½ | " | of resublimed iodine. |
"The above are dissolved in thirty-five ounces of the strained liquid, and, after filtration through white bibulous paper, the resulting fluid should be perfectly clear and of a bright lemon colour.
"The iodized solution is now ready for use, and may be preserved, in well-stopped bottles, for any length of time.
"The waxed paper is laid in the solution, in a flat porcelain or gutta percha tray, in the manner described by M. Le Gray and others, and allowed to remain there for from half an hour to an hour, according to the thickness of the paper. It is then taken out and hung up to dry, when it should be of a light brown colour. All these operations may be carried on in a light room, taking care only that, during the latter part of the process,
the paper be not exposed to the direct rays of the sun.
"The 'iodized paper,' which will keep for almost any length of time, should be placed in a portfolio, great care being taken to lay it perfectly flat, otherwise the wax is liable to crack, and thus spoil the beauty of the negative. The papers manufactured by Canson Frères and Lacroix are far preferable, for this process, to any of the English kinds, being much thinner and of a very even texture.
"To render the paper sensitive, use the following solution:
| 150 grains nitrate of silver crystals. |
| 3 fluid drachms glacial acetic acid, crystallizable. |
| 5 ounces distilled water. |
"This solution is applied in the way described by Le Gray, the marked side of the paper being towards the exciting fluid. The paper is washed in distilled water and dried, as nearly as possible, between folds of bibulous paper. It should be kept, till required for the camera, in a portfolio, between sheets of stout blotting-paper, carefully protected from the slightest ray of light, and from the action of atmospheric air. If prepared with any degree of nicety, it will remain sensitive for two or three weeks: indeed I have seen some very beautiful results on paper which had been kept for a period of six weeks. At this time of year, an exposure in the camera of from ten to twenty minutes is requisite.
"The picture may be developed with gallic acid, immediately after its removal from the camera; or, if more convenient, that part of the process may be delayed for several days. Whilst at this section of my paper, I may, perhaps, be allowed to describe a method of preparing the solution of gallic acid, whereby it may be kept, in a good state of preservation, for several months. I have kept it myself for four months, and have found it, after the lapse of that period, infinitely superior to the newly-made solution. This process has, I am informed, been alluded to in photographic circles; but not having seen it in print, and presuming the fact to be one of great practical importance, I trust I shall be excused for introducing it here, should it not possess that degree of novelty I attribute to it.
"What is generally termed a saturated solution of gallic acid is, I am led to believe, nothing of the kind. In all the works on photography, the directions given run generally as follow:—'Put an excess of gallic acid into distilled water, shake the mixture for about five minutes, allow it to deposit, and then pour off the supernatant fluid, which is found to be a saturated solution of the acid.'
"Now I have found by constant experiment, that by keeping an excess of acid in water for several days, the strength of the solution is greatly increased, and its action as a developing agent materially improved. The method I have adopted is to put half an ounce of crystallized gallic acid into a stoppered quart bottle, and then so to fill it up with water as that, when the stopper is inserted, a little of the water is displaced, and, consequently, every particle of air excluded.
"The solution thus prepared will keep for several months. When a portion of it is required, the bottle should be refilled with fresh distilled water, the same care being taken to exclude every portion of atmospheric air,—to the presence of which I am led to believe, is due the decomposition of the ordinary solution of gallic acid.
"It will be needless to detain you further in explaining the after-processes, &c. to be found in any of the recent works on the Waxed-paper Process, the translation of the last edition of Le Gray being the one to which I give the preference."