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528 THE PHOTOGRAPHIC NEWS. [October 31,1862. There are many occasions when magnificent studies of clouds might be obtained by almost every operator, even when nothing else could be secured. A good work on clouds, well illustrated with photographs, would bo one of the most interesting and valuable which could bo produced.—Ed.] CARBONATE OF Soda in the Tonino Bath. Dear Sir,—Not long ago you stated that having admired the productions of a certain gentleman, whose name I have forgotten, you solicited his formula, which ho complied with ; the toning bath was carbonate of soda. I had never tried this, but then made up one, and to my taste tho result was far prefer able to acetate. Judge then to my surprise on reading tho account of the South London Society’s meeting the following sentence of Mr. Leake’s : “ As to the use of carbonate of soda in the toning bath, he believed it to bo tho worst thing which could be used.” I have enclosed a few cartes toned by carbonate; what is your opinion of them ? if tho colour is not good, I will leave it off; but it is what my connection prefer ; if, therefore, it is injurious, I should fool glad if you will state in what particular, that I may be on my guard. Thoro are numbers of photo graphers who have gone back to carbonate, and who are no doubt surprised at Mr. Leake’s opinion. I am not aware if tho latter gentleman is an amateur or a professional photographer ; but it is to the former the latter are indebted for very valuable information; to tho professional photographer, whose business requires tho aid of several assistants, certain formulae are abso lutely necessary ; and when he has one he likes and pleases others also, how vexatious to hear others whom ho relies upon, so conflicting in their opinions ! I should, therefore, feel obliged if any of your numerous readers will state, whether they have found carbonate decidedly injurious in the toning bath. Hoping you will excuse the liberty of requesting space for this,I am, dear sir, yours truly, E. T. Brooks. Newbury, October 18th, 1862. [Nothing could be better or more brilliant than the tone of the prints received.—Ed.] Photogenic Properties of Walnut Rind. Sir,—Having discovered that tho extract of the outside, or green shell, of walnuts has some of the properties of nitrate of sdver, and having no convenience of testing it further, I now leave it to your numerous readers to bring it into some use in photography. If you think this communication worth your notice, you will oblige yours truly, J. W. H., Herbalist. Canterbury, October 11, 1862. P.S. If a piece of plain paper is placed in the extracts, in the dark room, it will not change its appearance until exposed to tho light, when it will turn the paper quite as dark as the nitrate of silver solution. [That the juices of walnuts and various other fruits and vegetables are darkened by light is well known; but this pro- perty has not been utilized hitherto.—Ed.] Ualk in th Studio. Silvery White Positives.—Tho following solution for developing positives, was given by Mr. Dawson at a recent North London meeting, with tho statement that it gave glass positives of exquisite silvery whiteness. Three ounces of proto- sulphate of iron dissolved in one pint of water; to this was added three ounces of a saturated solution of gallic acid, and 1 hen nitric acid was added drop by drop until the solution was clear. It might be placed in a dipping bath and used over and over again. Photographic Society.—The first meeting of the London Photographic Society for the winter session, will be held at King’s College on Tuesday evening next at 8 o’clock. Coloured Portraiture.—The rage for card portraiture, which at one time threatened tollrive all other phases of photo graphy out of the market, has not quite ruined the colourists, the majority of whom, are, we believe very busy. We had recently submitted to our notice some very good colouring in oil, by Messrs. Sawyer and Co. of Newcastle-on-Tyne, in which the photography and painting were alike excellent. U0 Correspoudents. *.* Agents or subscribers having copies of the following numbers of the present volume, which they can spare, will confer a favour by forwarding them to the office,, where they will bo exchanged or bought at full price: Nos. 174,187, and 196 to 203. W. D.—The sample of resin received is jalap resin, but, not purified jalap resin. By passing an alcoholic solution of the resin sent through animal charcoal, you will deprive it of its colouring matter, consisting of one-tenth of its weight. The purified resin of jalap, or the jalapine of the pharma copoeia, is nearly colourless, very hard ; but slightly hygrometric ; that is, when powdered the (common form in which it is kept) it absorbs damp, and sticks together in clots, a circumstance which would appear to mili tate somewhat against its suitability for a negative varnish. The testi mony of an able photographer and good chemist like Maxwell Lyte, to the effect that it is good, renders it well worthy of a trial. We fear that it will be too expensive for common use. Jalap is at the present time worth six shillings a pound, and it only contains one-seventh of resin, and this loses in one-tenth in purifying, so that the purified resin will cost six or seven shillings an ounce. This price need not, however, be a barrier to its use for negatives, should it prove really valuable,for the purpose, as one ounce of the resin will probably serve for ten or twelve ounces of varnish. A New Subscriber.—The best distinct work on the Talbotype process was that of Mr. Sutton, which is now out of print. Some of the best articles on the subject to which we can refer you, will be found in our first volume, especially on pp. 38 and 51, in Nos. 4 and 5 ; an excellent article on tho subject by Dr. Diamond, who is a most skilful calotypist, appears in the first volume of the Photographic Journal. Turner’s paper is generally preferred. Either floating or spreading with a glass rod may be used; the latter is preferred by many. Some spread the solutions with a Buckle’s brush. R. II.—We believe you will have reason to bo satisfied with the action of a battery of CO double plates of carbonized iron and zinc, arranged in three or more troughs in the same manner as the Cruikshank's battery of copper and zinc. The plates may be about 5 by 8 inches, those of zinc being about twice the thickness of the iron plates, and soldered to the latter. The existing fluid is a saturated solution of salt with one-third of sulphuric acid. The distance between the compound plates is about half-an-inch. It is preferable to amalgamate with mercury the zinc side of the compound plate, to reduce the consumption of metal. 11. F., Kennington.—Many of the matts and preservers used for photographs are imported from America. Those of English make are manufactured in Birmingham. J. C. J.—It is probable that the clearing up process used by Mr. Osborne will not be so applicable to dry plates as to wet ones, but you may easily try on a plate of small importance. If your negatives are already intensi fied, but not sufficiently so, you may obtain a great accession of density by applying a solution of iodine and iodide of potassium, and then, after wash ing, apply pyro and silver ; or by simply applying a solution of bichloride of mercury, followed by hydro-sulphate of ammonia. The latter is tho method used in the Ordnance Map Office at Southampton, and it is always applied after the plates have been dried. J. C. Wilson.—One thickness of yellow calico will not be sufficient to keep out actinic rays. The colourless sheet glass has rarely a surface sufti- cicntly perfect to enable good collodion positives to be taken thereon. James Ramage.—It is unnecessary to discuss the differences, or identity, between photolithography and photozincography; the inventors of the respec- tive processes known by these names regard them as similar, but not the same; but anyone is, of course, at liberty to regard them as the same. Mr. Fox Talbot at one time tried to prove that the collodion process and calotype process were the same. They both consist of a film made from vegetable fibre, as a vehicle for iodide of silver, which receives a latent image from the action of light, and is developed by a reducing agent. But the nature of the film is slightly different, and the results widely different. Your statement on the coagulation of dry albumen by heat is perfectly correct. The fact has been more than ouce pointed out in our pages, that dried albumen cannot be so coagulated. But we go further than you, and affirm that it cannot be coagulated by alcohol, ether, &c. &c., as generally supposed. One of our correspondents, Mr. Price, pointed out, twelve months ago, that heat would coagulate dry albumen. Since then we have carried the experiments further, and have, at the present time, an article and another communication on the subject waiting for insertion, when wo can find space. In reference to Mr. Osborne’s experience, there would appear, at first sight, a discrepancy ; but his explanation, in answer to a query on the subject, in a recent conversation we had with him was to this effect: the dry albumen is not coagulated by heat; it is not until the albumen has again become softened and moistened by absorbing water, that the heat coagulates it as he describes. That it is coagulated then, he says, is a simple fact. Seaside.—It will be a very simple plan for each reader desiring his AlmanaO bound, to get it done for himself. Or it would be found a good plan t, have made a reading case of the right size, which might bo used for each year’s issue. However, your suggestion shall be submitted to the pub lisher. L. F.—It is frequently expedient, before proceeding to intensify a negative after it is dry, to varnish the edges. This materially lessens the chance 0 losing the film. Some collodions require this treatment, as there is 8re4 danger otherwise of losing the negative by the splitting of the film. Ex perience alone can teach you when to make the application, and when to neglect it. FARRINGDON Lane.—We will examine the glass, and report thereon. A large number of communications, in type, are compelled to stand oyer uutil our next, amongst which are articles on the following subjects: “ Double or Fancy Printing,” by II. Cooper, jun.; " The Theory o Alkaline Gold Toning; A New Photolithographic Process 1-h6, fluence of Chlorides and Bromides in Collodion; ” Report of them ‘ seilies Photographic Society,” “ Photographic Chemicals,” " Ammonia »* Developing Agent,” and several others. All Letters, W orks for Review, and other Communications 01 tho Editor, should be addressed to 32, PATERNOSTER-H°W: HJ .’'great None, Ming M by Besha oving W8m,- Beolum Xnt Ptash 31i f on I 63And ! .Mror 11 encl J. will “attai On artic Qving, 1 1 Week. “^dna. P Bh er c Binati 3Tuesd %4 sev ^Hiers Clegat ' (80nis Bntfn T0rom ■ -oun "" Mm Batives Ns.. k I "bter’s eetin • Cert a M 011 vede V Convi tties a ly, 1 ’ onis , Contra v tha "best 13 It of J ‘his Arc. 1 Bday Nshan
