PHOTOGRAPHIC CORRESPONDENCE.
Difficulties in making soluble Cotton.—In making soluble cotton according to the formula given by Mr. Hadow in the Photographic Journal, and again by Mr. Shadbolt in "N. & Q.," I have been subject to the most provoking failures, and should feel obliged if Mr. Shadbolt or any other of your correspondents could explain the causes of my failures, which I will endeavour to describe.
1st. In using nitrate of potash and sulphuric acid, with a certain quantity of water as given, I have invariably found that on adding the cotton to the mixture it became completely dissolved, and the mass began to effervesce violently, throwing off dense volumes of deep red fumes, and the whole appearing of a similar colour. I at first thought it might be the fault of the sulphuric acid; but on trying some fresh, procured at another place, the same effects were produced.
Again, in using the mixed acids (which I tried, not being successful with the other method) I found, on following Mr. Hadow's plan, that the cotton was also entirely dissolved.
How is the proper temperature at which the cotton is to be immersed to be arrived at? Are there any thermometers constructed for the purpose? as, if one of the ordinary ones, mounted on wood or metal, was used, the acids would attack it, and, I should imagine, prove injurious to the liquids.
At the same time I would ask the reason why all the negative calotypes I have taken lately, both on Turner's and Sandford's papers, iodized according to Dr. Diamond's plan, are never intense, especially the skies, by transmitted light, although by reflected light they look of a beautiful black and white. I never used formerly to meet with such a failure; but at that time I used always to wet the plate glass and attach the paper to it, making it adhere by pressing with blotting-paper, and then exciting with a buckles brush and dilute gallo-nitrate. But the inconvenience attending that plan was, that I was compelled to take out as many double slides as I wished to take pictures, which made me abandon it and take to Dr. Diamond's plan of exciting them and placing them in a portfolio for use. I imagine the cause of their not being so intense is the not exposing them while wet.
A bag made of yellow calico, single thickness, has been recommended for changing the papers in the open air. I am satisfied it will not do, especially if the sun is shining; it may do in some shady places, but I have never yet seen any yellow calico so fine in texture as not to allow of the rays of light passing through it, unless two or three times doubled. I have proved to my own satisfaction that the papers will not bear exposure in a bag of single thickness, without browning over immediately the developing fluid is applied.
With regard to the using of thin collodion, as recommended by Mr. Hardwick in the last Number of the Photographic Journal, I am satisfied it is the only plan of producing thoroughly good positives; and I have been in the habit of thinning down collodion in the same manner for a long time, finding that I produced much better pictures with about half the time of exposure necessary for a thick collodion.
H. U.
Light in Cameras.—I cannot sufficiently express my acknowledgments to "N. & Q." for the photographic benefits I have derived from its perusal, more especially from the communication in No. 240. of Lux in Camera. Since I took up the art some months ago, I have had (with two or three exceptions) nothing but a succession of failures, principally from the browning of the negatives, and on examining my camera, as recommended by Lux in Camera, I find it lets in a blaze of light from the cause he mentions[[3]], and thence doubtless my disappointments. But why inflict this history upon you? I inclose for your acceptance the best photograph I have yet produced from Dr. Diamond's "Simplicity of the Calotype." Printed from Delamotte's directions:—
First preparation, 5 oz. of aq. dist.; ¼ oz. of muriate of ammonia.
Second process, floating on solution 60 grains of nitrate of silver, 1 ounce of distilled water.
Is there any better plan than the above?
Charles K. Probert.
P.S.—The view inclosed is the porch and transept of Newport Church, Essex, from the Parsonage garden. Is it printed too dark? I wish I could get the grey and white tints I saw in the Photographic Exhibition.[[4]] Had your readers behaved with ordinary gratitude, your photographic portfolio ought to have overflowed by this time.
Footnote 3:[(return)]
It was an expensive one, bought of one of the principal houses for the supply of photographic apparatus, &c.
[Some of the best specimens of these tints were forwarded to us by Mr. Pumphrey, accompanying the description of his process, printed in our eighth volume, p. 349.—Ed. "N. & Q.">[
Cameras.—The note of Lux in Camera has brought in more than one letter of thanks; and a valued correspondent has written to us, suggesting "That the attention of the Photographic Society, who have as yet done far less than they might have done to advance the Art, should be at once turned, and that seriously and earnestly, to the production of a light, portable, and effective camera for field purposes; one which, at the same time that it has the advantages of lightness and portability, should be capable of resisting our variable climate." Our correspondent throws out a hint which possibly may be adopted with advantage,
that papier maché has many of the requisites desired, being very firm, light, and impervious to wet.
Progress of Photography.—As a farther contribution to the History of Photography, we have been favoured with the following copy of a letter from a well-known amateur, which details in a graphic manner his early photographic experiences.
"As there is a sort of reflux of the tide to Mr. Fox Talbot's plan, and different people have succeeded best in different ways, it may amuse you to hear how I used to work, with better luck than I have had since.
"Mr. Talbot's sensitive wash was very strong, so he floated his paper upon distilled water immediately after its application.
"Mr. G. S. Cundell, of Finsbury Circus, diluted the sensitive wash with water, instead of floating the paper. Amateurs date their success from the time Mr. Cundell published this simple modification of the original process.
"Mr. William Hunt, of Yarmouth, was my first friend and instructor in the art; and if there be any merit in the pictures I did before I knew you, the credit is due to him entirely.
"The first paper we tried was Whatman's ivory post, very thick and hard, and yet it gave good negatives. We afterwards got a thinner paper, but always stuck to Whatman. Neither were we troubled with that porosity in the skies of which you complain in the more recently-made papers of that manufacturer.
"We first washed the paper with a solution of nitrate of silver, fifteen grains to the ounce, going over the surface in all directions with a camel-hair brush. As soon as the fluid ceased to run, the paper was rapidly dried before the fire, and then immersed in a solution of iodide of potassium, 500 grains to the pint of water. We used to draw it through the solution frequently by the corners, and then let it lie till the yellow tint was visible at the back. It was then immediately taken to the pump and pumped upon vigorously for two or three minutes, holding it at such an angle that the water flushed softly over the surface. We then gave it a few minutes in a rain-water bath, inclining the dish at different angles to give motion to the water. By this time the iodide of silver looked like pure solid brimstone in the wet paper. Then we knew that it was good, and hung it up to dry.
"To make this paper sensitive, we took 5 drops of gallic acid (saturated solution), 5 drops of glacial acetic acid, 10 drops of a 50-grain solution of nitrate of silver, and 100 drops of water. The sensitive wash was poured upon a glass plate, and the paper placed thereon. We used to lift the paper frequently by one or other corner till it was perfectly limp. We then blotted off and placed in the camera, where it would keep a good many hours.
"Whether such pictures would have come out spontaneously under the developing solution, I know not, for we had not patience enough to try. We forced them out in double quick time with red-hot pokers; and great was the alarm of my wife to see me rush madly about the house armed with these weapons. Yet the plan had its advantages; by presenting the point of the poker at a refractory spot, its reluctance to appear was speedily overcome, and we persuaded out the shadows.
* * *
"P.S.—I now have the first picture I ever did, little, if at all, altered. It was done in July, 1845, with a common meniscus lens. I have just got a capital negative by Dr. Diamond's plan, but which is spoiled by the metallic abominations in Turner's paper."
A Collodion Difficulty.—With reference to Mr. J. Cook's collodion, I would suggest that his ether was indeed "still very strong" of acid; by which the iodine was set free, and gave him "nearly a port-wine colour." This is a common occurrence when the ether or the collodion is acid. The remedy is at hand, however. Powder a few grains of cyanide of potassium, and introduce about a grain at a time, according to the quantity: shake up till dissolved, and so on, until you get the clear golden tint. Thus will "the mystery be cleared up." I need not say that the essential properties of the solution will not be impaired.
Andrew Steinmetz.
P.S.—In a day or two I shall send you a recipe for easily turning to immediate use the "used-up dipping baths" of nitrate, without the troublesome process recommended to one of your correspondents.
Ferricyanide of Potassium.—I have used with success the ferricyanide of potassium (the red prussiate of potash, as it is called) for removing the stains contracted in photographing. This it does very readily when the stains are recent, and it has no injurious effect upon cuts and sore places should any exist on the hands. An old stain may with a little pumice be very readily removed. I have mentioned this to several friends, and, if not a novelty, it is certainly not generally known.
S. Pelham Dale.
Sion College.