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FEBRVARY 13, 1885. j THE PHOTOGRAPHIC NEWS. 109 Mr. R. S. KIDD, who conducted the experiments, spoke of the desirability of a red image on development, which permitted being changed to any colour afterwards with gold toniog. To obtain this, he advocited a full exposure. Four cabinet negatives in printing frames charged with the paper were formed into a square, and two inches of magnesium ribbon ignited within the square. The exposed prints were then passed into a weak ferrous-oxalate solution, development occupying two minutes. The following formula were given :— No. 1. Neutral oxalate of potash ... ... 8 ounces Bromide of ammonium } ounce Hot water 50 ounces No. 2. Sulphate of iron 10 drachms Hot water ... ... * ... ... 50 ounces Citric acid ... } ounce Mix equal proportions of Nos. 1 and 2 when required for use. Mr. Kidd found ten ounces of developer would develop fifty prints ; he did not recommend more than thirty prints for that quantity of solution, as there might be a tendency towards yellownesss. Prints ought not to be handled in the developer, he said, since that was a frequent source of unevenness, the parts touched becoming more susceptible to the influence of the deve loper. Rapid development and rapid washing, followed by an immersion of ten minutes in the alum bath, was favourable to pure whites. He did not recommend the alum bath stronger than half a pound to the gallon of water. The success of toning depended on the alum effecting a removal of any trace of iron. Any toning bath would answer, but’he preferred a modification of the acetate bath as follows : — No. 1.—Stock Solution. Acetate of soda 40 drachms Chloride of lime 160 grains Water 80 ounces No. 2.—Stock Solution. Chloride of gold 15 grains Water 4 ounces Mix one ounce of No. 1 with two drachms of No. 2, dilute with ten ounces of warm water, and use when cold. Mr. Kidd, having toned the developed prints rather more than he desired them to appear when finished, fixed only one half, to show what change was effected by the hyposulphite of soda solution. He advocated a weak bath, and mentioned that the proportion of two ounces of the salt to each pint of water was quite strong enough, and perfect fixation would take place in ten minutes. Washing and mounting he regarded as being details well under stood. Several prints were stripped from talced glass plates and circulated among the members, also many mounted examples of larger dimensions, which were much admired. The Chairman remarked that any degree of toning could be performed after fixation by means of the mixed hypo and gold bath if it were so desired. He thought the examples shown by Messrs. Morgan and Kidd were very beautiful, and any questions the members wished to put would be cheerfully answered. Mr. W. Conn desired to know if there was any objection to keeping the prints some time between exposure and develop ment ; had a continuing action of light been observed in this case, as with carbon tissue ? Mr. Kidd had not noticed any difference with intervals up to a week. They had not delayed development beyond that time. Replying to another question, Mr. KILD stated that an ex posure of ten seconds to average daylight would be equivalent to the exposure made with two inches of magnesium ribbon. Mr. E. Clifton : Do prints of this kind lose strength in toning ? Mr. Kidd: Ordinary warm tones do not become noticeably lighter, but when black tones are made there is a little loss. In reply to another question, he said the prints did not get lighter after leaving the developer. Mr. Francis Cobb : Do the prints become lighter in the fixing bath ? Mr. Kidd : If a strong fixing solution is employed, the prints lose much force at first; this to some extent returns by con tinuing the immersion for a time ; by the use of a weak fixing bath that difficulty is avoided. Mr. W. Cobb: Does a weak fixing bath perform the necessary function of fixing the prints properly ? Mr. Kidd : Yes. Replying to Mr. Hare, he said that rapid washing after development did not effectually prevent a slight developing action continuing ; it was better to stop just short of the desired depth, wash quickly, and immerse in the alum bath. In reply to Mr. Foxlee and other questions, Mr. Kidd stated that although hypo and gold toning could be employed immedi ately after development, or after fixation, the rich purple colours could not be made in that way. Mr. FOxLEE had one other question to put, viz., whether with a gelatine coating containing a sensitive compound such as chloride of silver, the kind of paper employed plays any part in the preparation of the picture ? Mr. Kidd said it was well to use a good class of paper for the sake of the texture; any paper containing chlorine would be injurious ; and it was remarkable to what an extent chlorine was present in many papers. He thought more albumenized silver prints faded on that account, than from hypo. There would be no spots formed by impurities in the paper, as no free silver was present. Mr. W. Cobb thought more artistic results could be produced if a coarse-grained paper was used, especially for enlargements. Mr. Clifton thought in that case very little gelatine would be needed ; in fact, only enough to retain the sensitive coating. Mr. C. J. Hussey suggested stripping the films from the paper for the purposes of lantern slides. Mr. F. Cobb had noticed in some gelatine prints that the whites were not very pure. Was there any real difficulty about it? Mr. Kidd replied that if prints remained sufficiently long—say ten to fifteen minutes—in the alum bath, the whites were per fectly pure. Mr. W. M. Ashman remarked that an extremely dilute solu tion of ozone bleach or chloride of lime would decolourize gela tine prints. Care was necessary in its employment, or the image would be affected. Mr. Kidd found the alum bath would bleach the image if allowed to act too long. The Chairman, in closing the discussion, proposed a hearty vote of thanks to Messrs. Morgan and Kidd, which was agreed to. The Hon. Secretary then exhibited, on behalf of Mr. True man Wood, a convenient camera-clip, made by fastening two American clamping screws below the base-board ; attachment to a tricycle or other suitable place being easy, owing to the length of screws. The artistic competition pictures for 1884 having been exhi bited, and the votes of the members ascertained, The Chairman announced the result as follows: —1. “ Gone,” by Mr. Mathew Whiting ; 2. “River Scene, ” by Mr. E. Dun more ; 3. “The Village,” by Mr. E. Dunmore ; 4. “Study of Leaves,” by Mr. Matthew Whiting. It was announced that on Thursday, March 5th, Mr. Shadbolt will lecture on “ Experiences in Balloon Photography.” London and Provincial PHOTOGRAPHIC Association. The usual weekly meeting of this Association was held on the 5th inst., Mr. F. W. Hart occupying the chair. Mr. A. Cowan, in reference to the discussion of the previous week on plates treated with boiling water leaving a positive image on the glass, passed round two plates that he had coated with an emulsion made for the purpose ; these had been exposed through the back, and developed in the ordinary way. One was passed through hot water previous to fixing, and the other after fixing ; the first plate showed a much stronger image than the other. He had tried the same experiment with an emulsion contaiuiug alum, but was unable to obtain the same effect. Mr. A. L. Henderson drew attention to an ordinary gelatine plate that he bad exposed through the back and developed in the usual way, excepting that, after being fixed, it was allowed to remain in water, the temperature of which was gradually raised to about 90°, when the film commenced to blister. After rub bing with the finger a skin of gelatine came away, leaving the image in considerable relief, from which Mr. Henderson thought a typographic block could be made. Air. A. Cowan showed a gas-burner suitable for the dark room. The jet, after being turned out, when required again, re-lit upon the gas being turned on. A small metal cup attached to the top of the gas-pipe—in the centre of which was the burner—contained inside it a very small jet, which, being fed