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THE PHOTOGRAPHIC NEWS. Vol. VII. No. 263.—September IS, 1863. CONTENTS. New and simple Method of Gold Toning 425 History of Carbon Printing 446 0< “N8.1rom the Note-Book of a “ Photographer’s Assistant.”— Photographic Chemicals 448 Photolithography.—No. Ill 449 The Manufacture .of Photographic Collodion’’ By w. L. Noverre 450 ThevAnalogy of the Eye to an Optical Instrument. By J. Z. Laurence, F.R.C.S., M.B 451 PAGE National Photographic Portrait Museum 452 Photographic Pictures and Illustrations 452 Correspondence—Formic Acid in the Developer—Relative Ex ¬ posures for Various Processes 454 Photographic Notes and Queries—Queries on Gold Toning— Cheap Glass Rooms—Lime Toning—Insensitive Spots, &c. 455 Talk in the Studio 455 To Correspondents 456 Photographs Registered during the past Week 456 i NEW AND SIMPLE METHOD OF GOLD TONING. We have recently been experimenting with a method of toning which possesses the merit of great simplicity, and does not require the solution to be prepared some time in advance. The prints, after being well washed, are immersed for five minutes in a solution containing from five to ten grains of carbonate of soda in an ounce of water. They are then carefully drained, and without further washing im mersed in a solution of chloride of gold, one grain in about five ounces of water, without any other addition. The prints retain sufficient of the alkaline solution to preserve them from the action of any trace of free acid, and also to set up the necessary decomposition to produce toning action. The toning also seems to proceed very gradually, and without the slightest tendency to mealiness, or to any excessive bleaching. We arc so well satisfied with the acetate bath for warm tones, and with the lime bath for black tones, that we do not bring this forward with any view to supersede these methods ; but as a simple and convenient method of pro ceeding, either when mealiness is troublesome, or when a bath requiring time for its preparation is not ready. • HISTORY OF CARBON PRINTING* Ma. Sutton has written an interesting little work on Mr. Pouncy's process of producing photographs in printing ink, in which he glances at the history of carbon printing gene rally, and more especially of what he terms direct carbon processes, or those methods by which a print is produced on paper prepared with carbon, combined with some sensitive material, of which Mr. Pouncy’s patent process is the latest and most perfect example. The work is written with that simplicity and vigour of style with which Mr. Sutton’s readers are familiar; but there is also something of the tone of the advocate who knows no other excellence than that the cause of which he is pleading. For instance, in the Introduction to his work, the importance of a carbon process is enforced by an allusion to the instability of photographs produced by other methods. The instability of photographs has been an admitted re proach, but not the implied universality of that instability. Mr. Sutton says : - It is the reproach of all photographs produced by the common methods that they fade. Beautiful as they are in colour and effect, want of permanency is the unfortunate stigma which attaches to them ; and if the term permanent is ever applied to any class of common photographs in contradistinction to another, the term must bo understood as employed in a very limited and relative sense, for no one has a right to affirm with confidence that either a silverprint, a Daguerreotype, or collodion positive or negative, however carefully manipulated or preserved, will absolutely remain unchanged during even the short space of a * “Photography in Printing Ink.” By Thot^Tsutton, B.A. London : Sampson Low, Son, ami Co. dozen years. Some processes may yield proofs less liable to change than others, but none of those which are commonly em ployed by photographers yield results which are at all comparable in permanency to the works of the painter or engraver. Had pictures and prints been as perishable as photographs, what would have become of the arts of painting and engraving ? Or had impressions pulled in the printing press been as liable to fade as photographic positive prints, where would civilization have been at this moment? Now, if we are not mistaken, Mr. Sutton has frequently reiterated that he has never known a developed print to fade. In a recent conversation with Dr. Diamond, on calo type negatives, he stated that he had never known one to fade, and we need scarcely add that there is no higher authority on that subject. We have never known a well kept collodion negative, collodion positive, or daguerreotype to fade. Indeed, we have never known a daguerreotype which had been properly gilded to fade at all. By ex posure to damp or foul air, we have known them to become tarnished, &c., but we have never met with one of which we could not, in a few minutes, restore the pristine beauty, by the simple application of a solution of cyanide of potassium, and we should feel no hesitation whatever in affirming, with all confidence, that a carefully produced and fairly protected daguerreotype or collodion positive would remain unchanged very much longer than a dozen years. It is upon ordinary prints on paper that the chief stigma has rested. These, if produced with proper care and observance of all known conditions, will, we doubt not, remain unchanged for more than a dozen years; but, nevertheless, it is an unfortunate fact that owing to the com bined effects of ignorance and carelessness in the past, few persons would like to stake their reputation on the affirma tion that any given print would remain unchanged for, perhaps, half of a dozen years. Hence the unquestionable importance of a carbon printing process as a means of giving to photographs absolute and unquestionable permanency. “ But,” as Mr. Sutton per tinently remarks, “ at the same time it must be granted that unless this problem can be solved in such a way as to sacrifice none of the beauty of the common photographs it will be comparatively valueless, because permanency will never be considered an equivalent for the absence of beauty and other good qualities.” Mr. Pouncy’s process is a very great advance in this direction, and we believe, when well worked, will prove still more so. At present we cannot say that we have seen such perfect prints produced by it as we have seen by M. Fargier. But whilst the process of the latter gentleman is, we believe, so beset with difficulties that it is very unlikely to become a practicable commercial process, Mr. Pouncy's is elegant and simple, and promises, in skilled hands, to give better results than have yet been produced by any carbon process. Mr. Sutton emphasizes the idea which we suggested in our article on the subject in the PHOTOGRAPIIO News for July 31st, which contained the first published description of