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3, 1861 1swer to" re aresev es. TheP pose for K . this resp Tected br the iron d onal intep same pro" ectbyles" . the imaE intensity" mercury” When the neg r as a ge” d of thad which al. he usual! it proved?' ne of- a arestor, i exceedty ly mean", the con ch you are than 1 ' yourge” feet of Wj palliatd be found, 1 then be ination, " er persod,, le stateful ut solving Ml irn it, 8b erred 3 rated” of cold’ 1 tope itothec guess, P" t of wbi nes ald dvertise, ticaly®” foratte, don't C 3 unnec .he proP, nd upoy nula toze d at Po Nentreg former" ible lodion " shovs54 As • stusefu. lourins", exactP should • V, of wateee, tter F; butjp ght. ,v the yverM I, if 6 little 032 ire wbi। zing 5 I hink tbv is oft"'? xposu p , as depd cent " . essful 5 ed,jta84 other a ngte0 ents,a THE PHOTOGRAPHIC NEWS. Vol. VI. No. 194.—May 23, 1862. SOUTH LONDON PHOTOGRAPHIC EXHIBITION. From a recent inspection of the pictures now in course of hang ing at the Crystal Palace, contributed to the Exhibition of the South London Photographic Society, we have every reason to believe that the display will be eminently satisfactory. Many excellent photographers, whose works we have always examined with interest at other exhibitions, and who are entirely unrepresented at the International Exhibition, have some very superior pictures here. Amongst these we may mention the name of Mr, Annan, of Glasgow, whose fine large, and artistic landscapes, with natural skies, both by the wet and dry processes, will command universal admira tion. Mr. Earl, also, contributes a series of the largest land scapes we have seen on one sheet of paper, which are very excellent. Messrs, Jackson Brothers, of Jumbo, near Man chester, contribute a series of artistic gems, in the shape of landscapes with figures. Without entering in detail here, however, we may simply repeat that we find, with pleasure, that this exhibition has afforded opportunity for the display of many very excellent photographs, both in landscape and portraiture, which in the South Kensington Gallery have found no place. As regards position and publicity, the advantages of the South London exhibitors are out of all proportion superior to those in the garret of the International Building. At the Crystal Palace, the pictures are in an accessible gallery in the most attractive part of the building, within sight and tempting reach of all the hundreds of thousands of visitors who will be present during the summer. The gallery is well ventilated and comfortable, an awning having been erected in this part to shut out the heat of the sun's vertical rays. The screens are conveniently arranged and neatly decorated, the main colour being maroon flatting, bordered with black and Etruscan yellow. The ample space placed at the dis posal of the society permits them to restrict the position of all pictures to within a foot or two of the eye line, so that nothing will need to be “ skyed," nor will the visitor break his back by stooping to examine meritorious pictures. The whole of the very large collection of photographs contributed, will, we understand, be hung so that none shall be at a height greater than six or seven feet, or lower than within two feet or eighteen inches of the ground, whilst an effect of the utmost value to individual pictures, as well as to the Kemble, will be gained by leaving a space of two or three inches between all the frames. Some attempt at classification will also be made. Portraiture will occupy one department, landscapes another, and reproductions a third; and these, again, will be divided into sections, consisting of different processes. If the contemplated arrangement can be well carried out in this respect, there can be no doubt of the great value it will possess. A difficulty will be found here, we fear, arising out of the tardy arrival of some of the promised contributions, the space for which cannot possibly be calculated in their absence. 1 he work of hanging is, however, now going rapidly for ward, and contributions arriving late must, we apprehend, be placed as best they may, without strict regard to arrange ment. It.was originally contemplated, we believe, to open in the middle of May, but owing to the causes to which we have Eferred this was found impracticable. It is now definitely Setermined, we understand, to invite members, exhibitors, v tothe private view on Saturday, the 31st, when we anti cipate the pleasure of examining a very highly satisfactory exposition of photographs. THE EFFECT OF BROMIDES IN COLLODION. Mil. Sutton resumes his remarks on this subject in the last number of the Notes, and in order to do justice alike to the subject and readers, by placing his statement .of the matter fully before them, we make some further extracts. It will be seen that he admits that bromides are useful in counteracting the effect of impure chemicals ; but enforces his conviction that no advantage is gained by their use when pure chemicals are employed. In this case, even, wo conceive, photographers will continue to avail themselves of their aid, as it is with the commercial standard of purity photographers have to deal. Our own experiments, from which we derive our conviction of the value of bromides, have been conducted with the purest chemicals we could obtain, and with a nitrate bath, &c., in the best possible condition. Nevertheless, we have often stated that it is possible to obtain conditions in which a simply iodized collodion and pyrogallic acid development will produce results as good and rapid as bromo-iodized collodion and iron development; but that these conditions are difficult to secure, and impossible to maintain. Mr. Sutton says :— “ The effects of bromide are widely different, according as the chemicals used are pure or impure. “ With pure collodion and nitrate of silver, which are work ing well with the pyrogallic developer, and giving rich creamy negatives, with red intensity and blooming surface, the addi tion of bromide to the collodion renders the process slower, and after a time, affects the nitrate bath so that it will not again give the same kind of negative as before, but a thin grey nega tive, difficult to intensify. It is, however, difficult to work out- of-doors in a very strong light with simply iodized collodion, on account of its tendency to give red solarization in the over exposed parts, and under these circumstances, the addition of a bromide to the collodion reduces the redness and brings the process more under control. There is, however, another and a better remedy for solarization, which consists in soaking the pyroxylinc for half-an-hour in water containing carbonate of soda, so as to neutralize all the acidity which pyroxylinc invariably shows, and which no amount of mere washing will entirely remove. Red solarization appears due, in great mea sure, to the acid contained in the pyroxyline, and it is most marked with cadmium collodion, which contains no base capable of liberating the iodine and neutralizing the acid. Negatives taken with cadmium collodion are generally the reddest, and the most given to solarization. The most rapid known wet process, which is at present practicable, is that in which pure chemicals are used, and no bromide; and in this process it matters not greatly whether the developer be iron or pyrogallic acid, for in neither case does the negative require intensifying with silver, and in both cases the time of exposure is about the same. “ With collodion simply iodized, the details in the shadows may be brought out with so much vigour and intensity as to destroy the effect of shadow altogether, but with a bromide in the collodion it is more difficult to give intensity to the details of objects in shadow, and therefore it may happen, in such cases, that a more truthful representation of objects in strong contrasts of light and shade can be produced. “ Such are the effects of bromide in collodion when pure chemicals are used, and it is then only useful when the light is too strong, and the contrasts too violent for the iodide alone. But these statements do not agree with the general experience of photographers, because pure chemicals are not commonly used by them. “ With common chemicals—that is to say, with collodion made with methylated ether, and nitrate of silver which has not been recrystallized and is acid to litmus paper—the effects of a bromide are different from what has been described before.