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2xocerdinga sf Societies. • J. Mr. C. Bennell PHOTOGRAPHIC the studio on names to the Hon. Secretary of the Association, Cutchey, 62, Gracechurch Street, E.C. quicker than the bottom. Mr. Harrison explained at some length the reason why this was so. The following was next discussed : “ What is the best method to recover silver from waste emulsion and washings ? ” Mr. DEBENHAN’s plan was to put the waste into a large boiler, and concentrate by boiling, then send to be reduced. Mr. Cowan boiled with caustic potash, about } lb. to a gallon, for half-an-hour ; then left all night, and in the morning it was quite limpid, an® the top solution could be poured off; by this means he recovered about 90 per cent. Mr. Haddon suggested a mixture of hydrochloric and sul phuric acids, which destroyed the setting powers of the gelatine, and reduced to bromide of silver. Mr. PnESTWICII had tried mixing with sawdust ; but, when drying, found the silver evaporated, and deposited on everything, and but very little was obtained, and he suggested adding the flux previous to evaporating down. Mr. Goldino said that oxalic acid would take bromide of silver down in its original condition, and that it could be used again. A discussion then took place as to the desirability of having a competition for speed and quality in gelatine plates. It was decided that there should be a contest, open to all, but that only the name of the successful competitor should be announced. The consideration of the complete rules to be observed in the competition was deferred till the next meeting. Gentlemen wishing to compete are requested to forward their member explain the chemistry of bromides as a restrainer ? ” was brought forward for discussion, and the Chairman read a paper (see page 324). In the discussion which ensued, Mr. Cowan said he agreed with Mr. Henderson’s remarks as to cutting down the ammonia in the developer; and in reply to Mr. Debenham, he said the development was not slowed thereby; the negatives did not look well, but gave better prints—that is, brighter shadows. He found that if (say) two minims ammonia were used all at once, then the plate developed up thin and useless ; but if the same quantity was used, +-minim at a time, good results were obtained. The CHAIRMAN showed two negatives of active life, one taken with a commercial shutter, the other with the drop-shutter he used for last year’s Derby pictures, with an extra band added to quicken the speed, this latter giving the best results ; but as different lenses were used, this was not regarded as a fair test. It was remarked that in these negatives the bottom parts of wheels in motion were sharper than the top ; and Mr. Brown said it was a fact that the top of a cart-wheel_moved After some formal business, a question was read, asking for the experience of members as to any difference between the behaviour of potassium bromide and ammonium bromide, when used as a restraining addition to the developer. Mr. Sebastian Davis referred to experiments of his which Bristol and West of England Amateur Association. The ordinary monthly meeting was held at London and Provincial Photographic Association. At the meeting held on the 17th inst., Mr. A. L. HENEERSON occupied the chair. The question adjourned from last meeting, viz., “ Can any Photographic Society of Great Britain. A MEETING was held on Tuesday evening, the 22nd inst., Mr. Spiller in the chair. tended to prove that chemically equivalent proportions of the two .salts weie equal as regards restraining power. Thus, 98 parts of ammonium bromide restrained as effectually as 119 parts potassium bromide; and as these quantities contain the same amount of bromine, one might perhaps be justified in looking on the bromine as the actively restraining constituent. Mr. W. K. Burton alluded to the fact that a very large pro portion of neutral salts exercise a notable restraining action ; and he observed that it is interesting to note how surprisingly equal Such boxes, made to hold a dozen each, can easily be dis - tributed amongst our clothes in a portmanteau, and do not appear to arouse the suspicions of the Customs authori ties. Moreover, by substituting a sheet of india-rubber for the twill, a very tolerable developing tray is made with either top or bottom. I trust I may be pardoned for again alluding to this arrangement, which was accidentally mentioned iu a paper of mine in last year’s volume of the News.—Yours truly, Greenwood Pim, M.A. Wednesday, April 25th, Colonel Playfair in the chair. The minutes of the previous meeting having been confirmed, the Chairman called on Mr. E. Brightman to read the first portion of a paper on “ Transparencies by the Carbon Process” (p. 326), at the close of which, The Chairman stated that he had been till then quite ignorant of the practical working of the process, and had felt great pleasure in listening to Mr. Brightman’s interesting remarks, and watching what appeared to him to be the very simple modus operandi of the process. Mr. H. A. H. Daniel said he had done a few large trans parencies by the process, and regretted that want of time pre vented him from practising it so much as he should like to ; he warned those present against using oil stoves lor drying the tissue, as he had had a quantity rendered insoluble by so doing a few years ago. The vapour from a petroleum stove seemed to have a peculiar effect on the tissue which nothing could remedy. Mr. E. Brightman, in reply to enquiries, stated that the semi opaque margin of the picture was caused by what was called the “ safe-edge ; ” a semi-transparent mask being placed around the edge ol the negative to give the tissue a safe holding, though being only partially dissolved all round. Mr. Stephens asked whether it was not very difficult to acquire the requisite experience for successful printing, as regards the depth necessary. . , Mr. Brightman replied that by classifying one s negatives, Mr. Hughes then drew a parallel between the old iron developer as restrained by means of acetic acid, and the alkaline developer restrained by a bromide. Mr. Davis, in pointing out the essential differences between these methods of developing, referred to the good service which Major Russell had done to photography by the introduc tion of alkaline development. - The Chairman alluded to the specific action of an alkaline iodide on the silver salt, tending to form iodide of silver in the film, and an alkaline bromide in solution ; this reaction actually changing the whole character of the plate. The discussion being closed, it was announced from the chair that on Saturday, June 16th, an attempt would be made to photograph one of the Dene holes at Grays, hnd it became desirable to consider what means of artificial illumination would be most likely to prove useful. Various means—such as the electric light, magnesium (either in the air or iu oxygen), lime light, and paraffin—were suggested, and Mr. W. E. Debenham detailed his experience in photographing a Cornish mine by the light of burning magnesium Mr. Cowan's new shutter, which has already been described in the News (p. 305) of last week’s issue, was then passed round and explained. a large proportion of these are in their action. It is quite possi ble that these cases may depend on the general law that “ reaction tension ” between substances is lowered in the presence of inert; bodies. Mr. Jabez Hughes referred to the proposal to use free iodine as a restrainer. Mr. Davis pointed out the circumstance that iodine and solu ble iodides might be regarded rather as destroyers of the photo graphic image, than as restrainers ; and it was pointed out that iodine, when freshly added to an alkaline liquid, probably takes the form of a hypo-iodite, a solution analogous to the so-called “chloride of lime” being produced. The discussion now merged into some points in connection with the carbonate of soda developer, and Mr. Cowan said that by reducing the amount of ammonia he could realise all the advantages of the soda process; and, moreover, he could satisfactorily develop any ordinary plate without using a