Photographic Wanderings. A VISIT TO STRATFORD-ON-AVON. BY R. A. SEYMOUR. (Continued from page 250.) I PROCEEDED, with all due care and forethought, to take my humble glass positive. Negatives were then things undreamt of in my philosophy. I duly arranged the apparatus in my tent-black and yellow calico over a tripod-and got a plate into the slide, focussed, exposed, crept into the dark, and developed-a fog. A second and a third plate followed, each with a shorter exposure, but each with the same result: and you see, therefore, why it was not my photograph of Charlecote Hall which figured in the last number of this journal. I thought, as I had reduced the exposure three times, over-exposure could not this old tradition has no basis in fact, although I found when we got to our lodgings, that some people who had been our predecessors, and who had ventured to throw doubt upon the story's truth, were regarded as contemptibly ignorant and ill-informed. I had another day before the old house, and with the same disheartening results, until a lucky chance disclosed my error. The dark slide of my camera was in a very imperfect state, and various dodges had to be adopted to keep the plate in its proper place. Fancying I had forgotten to attend to these, just after I had uncapped the lens-a portrait combination I recapped it and took the plate into my tent. Then, supposing I might have moved the camera, I thought I would prepare another plate, and while doing so, just as a matter of curiosity, develop plate No. 1. To my astonishment I found I had got a picture. After this I got along more satisfactorily. My collodion was a new one, prepared by a Coventry chemist, whose name I have forgotten; be the origin of the failure; nevertheless, it arose from nothing else, as I found afterwards. My operations were, however, so far successful, that they obtained me an introduction to the interior of the ancient mansion, and we passed some little time in examining the hall containing the bust and portrait of the very Sir Thomas Lucy by whom-so runs the tradition-Shakespeare was tried for deer-stealing. We imagined the poet, in the days of his wild, hot-blooded youth, brought into this very hall by the sturdy keepers, conjured up the stern Sir Thomas, in his big ruff, and slashed suit of black velvet, with roses in his shoes, and pen in hand, occupying one of the tall-backed old chairs by the oaken table, and strove to realise the young culprit's feelings. As I have said, I now know that Of which we give an engraving, drawn by W. H. Prior, and engraved by J. Walmsley.-ED. he made a wonderful secret of it, and sold it at a price high enough to astonish photographers of the present day. I have since had reason to believe that it was one of the first prepared with the iodide and bromide of ammoniumthe time I am speaking of is about 1853-and I was quite unprepared for its superior sensitiveness, Charlecote Hall being the first subject on which I had used it. In these days collodion-making had not reached its present state, and the air was constantly rife with rumours of new samples of gun-cotton, new solvents for them, and new modes of iodising the collodion manufactured therefrom, and many were the discussions indulged in when photographers got together upon this fruitful subject. In those days such wonderful statements as Mr. M'Lachlan's were not at all uncommon. Nearly every photographer I then met with in my travels used to be constantly making such marvellous discoveries. One time I used to find a man in the lowest depths of despair, on the eve of abandoning the art in utter disgust, virulently abusive of his lens, his camera, and in short everything connected with photography. A week or two afterwards I found him, perhaps, working with some new chemicals, buoyantly hopeful and delighted, with continued success, landing the art to the topmost skies, ready to bet that he had the best lens in the world, the finest camera in the market, and offering to sell the secret of his last new collodion for nothing less than fifty or a hundred guineas. (To be continued in our next.) Questions and Suggestions. A SUGGESTION FOR OPTICIANS AND OTHERS. SIR, I have the following suggestion to make to dealers in second-hand photographic lenses and others-Why don't they offer to let out on hire certain lenses, and, if necessary, cameras as well? There are several lenses, such as Dallmeyer's rectilinear lens, and Ross's large angle doublet, and the like, which amateurs and photographers of small means do not care to buy, but which they would be very glad to hire for a few days, to photograph certain subjects which they have hitherto been unable to photograph, such as the interiors of churches, houses, and even rooms; there are also many houses which are inaccessible to the usual lenses of an amateur, but which he is nevertheless desirous of photographing. Would it not be a good plan if dealers in lenses and others were to adopt this. Prices might be regulated according to the size of the lens and the time it was to be kept.-Yours, &c., ARTISTIC LANDSCAPE PRINTING. W. G. SIR,-Will you find a place in your valuable columns for the following suggestion? I am a landscape painter, and have, through your journal's influence, recently taken to photography; but feeling dissatisfied with even the best of my landscape camera productions as pictures, I have adopted the following plan-Having taken my negative, I get a print from it, and with this as a guide, I paint upon a piece of clean glass of the same size as the negative, with body colour so as to form another negative, the pigment being more or less opaque according to its thickness or density. From the negative thus manufactured I get a print more or less faint, according to my requirements, and upon this faint print I then print with the photographic negative. My object in so doing is to tone down any staring masses of light, reduce the intensity of shadows which are too uniformly dark, get minute touches of light or dark here and there, on foliage or elsewhere, soften the outlines where required, All this by the aid of negative No. 2, if carefully executed, I find I can accomplish. &c. A PARASOL TRIPOD. AN ARTIST. SIR,In respect to your notice of my apparatus for "Out-door Portraiture," I beg to state that one of the designers' sketches had the top or roof projecting some way over the sides; another one had not, which one was by mistake handed to my engraver. A piece of loose cloth attached to the ends of the top when raised, will do away with all cross rays of light; and by shifting the curtains D and B back, any effect of side light can be commanded. The apparatus can also be arranged with a dome top like a large gig umbrella; this will be found a useful feature. From the fine modelling I have seen in pictures taken with the assistance of this apparatus, I feel convinced that it POCKET CAMERAS.-" DEFENSIO NON PROVOCATIO." SIR,-No one will venture to dispute your correspondent's just claim to his nom de plume Jack Blunt. May I be permitted to say blunt enough? However much he may disagree with Mr. Smith's remarks respecting pocket opera-glass cameras, and brand them "magical," others, of long-standing experience in photography and optics, unanimously shake their heads when asked seriously about the practicability of the opera-glass camera, dictated to them by past experience with them; and for this reason alone, I must step in again to the rescue, for the sake of brother amateurs, and say, "Don't try 'em" until satisfied of the probable cost, and results to be obtained from them. Again, as regards Jack Blunt's flat contradiction of Mr. Smith's assertion-viz, that his was the only pocket camera yet offered for sale-I presume Mr. Smith meant “publicly offered” — advertised. If so, I think he is correct, for I am not aware of any other being advertised at present, having searched and looked about considerably before purchasing mine, and failed to meet with any; and until I can see something better, practically, in a pocket camera and tripod than the one so much and so unworthily attacked, I shall still continue to defend it through even Jack Blunt's black mail. No one, I hope, ever doubted the respectability or disinterestedness of so universally respected a gentleman as Mr. Sutton; and again, from inquiries I have made, I find that Mr. Smith is entitled to his share of thanks from the amateurs and others, he not getting a single cent. himself out of the instruments sold except such crumbs of acknowledgment as may fall from the pen of Jack Blunt. Enough too! Exacting man, why can he grumble ?-Yours, &c. Ladywell, June 30th, 1868. JUSTITIA. SIR,-I cannot pass over Jack Blunt's, to say the least, most ungentlemanly letter which appeared in your last number. I cannot see that I deserve this attack from Jack Blunt, inasmuch as I have done no injustice either to him, Mr. Sutton, or his designs. In my statements I have only given facts and exact sizes in reply to Mr. Sutton's first letter, and am quite sure if I had been at all ungentlemanly in my remarks towards Mr. Sutton, he would be, and is, quite capable of defending himself against any attack, without the aid of Jack Blunt. Again, Jack Blunt need not hasten to inform me that Mr. Sutton strictly a gentleman; I have had the pleasure of knowing this fact for some years past. Although by the remarks in my letter I appeared rather angry with Mr. Sutton's criticisms, I have said nothing that is ungentlemanly or untruthful. If Jack Blunt will take the trouble to read my letter again, and in the right light, he will find I was speaking of a circular camera 4 inches diameter, capable of receiving a plate 3 inches square in that circle, and not in a slide case to be attached to the opera, therefore the ebonite experiment with tubes referred to in my previous letter, although similar, was not from Mr. Sutton's design. Jack Blunt says he has a camera made from the design in this paper, but does not tell us what size of plate it is adapted to Again, I have never said Mr, Sutton's design was impracticable or impossible; all I said was, it would prove a failure as a pocket camera if made for a plate 34 inches square, so that the corners of the plate should be well exposed to the rays of the lens. To do this you must have a circle of 4 inches diameter. Mr. Sutton, in his letter, last week, admits the advantage of this. What photographer would think of putting a plate 34 inches square immediately behind a circle of, say 24 inches, which is the size of the largest opela or race-glass in use, I don't think the result would be very satisfactory to him. With regard to Mr. Lancaster having a pocket camera for sale, as he has never made it public by offer ing it for sale, I was quite justified in asserting that mine was the only one in the market. I see Jack Blunt states that Mr. Lancaster is making some of quite another pattern for sale. Why then does he directly accuse me of untruth if he is on now making them? It is quite clear from his own they are not ready for sale.-Yours truly, writing that C. D. SMITH. 44 inches was printed by mistake. I gave the size in my previous letter as 4 inches. SIR,-Through reading the articles by "Gossiping Photo- glow of a greenish, blue, red, or purplish tint, according to the To aid those who find it difficult to secure chemically clean plates by any of the ordinary processes, the editor of a contemporary recommends the following mode of preparing '-wax dissolved in ether and rubbed them:-"A little pure bees'-w over the plate has the happy effect of coating the surface with an almost imperceptible film, which is quite inert in itself to photographic action, and effectually interposes a barrier between the collodion film and the chemicals it contains, and the glass surface and the active dirt which rests unseen upon or in combination with it. Whilst no photographer will willingly relief from the immediate annoyance of bad plates when perfect work with dirty glasses, he possesses in this coating of wax a has a happy knack of overlooking the discoveries and invenones are not immediately procurable." The editor in question tions of others? Our readers know well enough that this plan was previously suggested by our respected contributor, Major Russell. Photographers who have read the story of the above-quoted discoverer's invention of Meagher's camera, the collodio-chloride process, and other little matters, will be amused at this most recent instance of his-we will sdsay-"forgetfulness." The day was fine, but hot. I exposed four double backs with a Grubb 81-in. focus, stop, for 3 minutes, there being no deep shades or foliage; but for one view I changed stop to in., to sharpen edges, and on developing, this was my only good negative, the rest being over-exposed-beautiful pictures to look at, of a fine colour, but sadly too thin in the high lights; to remedy which I used ammonia too freely, and thereby obscured details in a hopeless eclipse, taking half a day to print a weak but beautifully soft proof. I tried to reduce one of the plates again with a strong solution of cyanide, which swept off the picture, leaving me to make "big eyes." But, since then, I have read the articles on developing bromised plates, in this journal, and thought better of it, making fairly good negatives of all the rest. I have just sent for 2 dozen more, eight of which I exposed at New Brighton last Saturday afternoon, in bad light, from which I obtained eight fair negatives. I recommend those who, like the writer, are fast tied to business, except an odd day at intervals, to buy these plates, and thus save their time, avoid many vexatious troubles, and fill their boxes with good negatives. J. D. [The above letter shows the importance of not condemning a process before one has learnt how to use it.-ED.] Bits of Chat. Perhaps the most curious invention of the present day is the new kind of photographs, made on a so-called phosphorescent surface, of which absolutely nothing can be seen in the daylight, but which is distinctly visible in the dark. Many years ago, compounds were invented which had the property of shining in the dark many hours, and even days or weeks, after an exposure to sunlight for only a few seconds. These phosphoric compounds, called, after their inventors, Canton's, Baldwin's, Bolognian phosphorus, &c., were formerly of no use whatever, but it was hoped that they might eventually reveal something concerning the nature of light; and such has indeed been the case, as the phenomena connected with these experiments are a strong argument in favour of the undulatory theory, and the correlation of forces. An English photographer lately conceived the idea of covering a sheet of paper or glass with a layer of such a phosphorescent substance, and then treating it in a similar manner to paper or glass sensitised in the ordinary way for taking a photograph. Pictures taken in this way seem, by daylight, to have no existence, but the places where the light has acted upon become phosphorescent or luminous in the dark, the shadows remaining invisible, the semi-tints slightly luminous, and the result is such a change in the surface that the picture is only perceptible in a dark room, by an unearthly Mr. W. T. Bovey, writing on the subject of silver printing, sums up his remarks on the acetate bath by saying:I will now to my method, the excellence of the results of which, I can assure the reader, is equal to the simplicity. Use the orange-coloured sample of gold, which is a double salt, consisting of chloride of gold and sodium; pay special attention to this, or do not blame me on account of your failures. Keep your gold in concentrated solution. Chloride of gold 1 grain, water 1 drachm. I have already shown that gold requires no acceleration; the adjuncts employed serve as retarders. Then, in lieu of employing uncertain alkaline agents, we make use of the more stable substance known as water. My toning bath I prepare as follows:-1st. Measure out 2 gallons of water (rain or river water if at hand; well water should be previously boiled). 2nd. Measure into a jug (porcelain) 12 grains of gold, add about 1 grain of fine table salt, and pour over the whole one pint and a half of boiling water; allow this to stand awhile, until lukewarm; then add to the 2 gallons of water previously measured out. Your bath is made, and ready for use. Go to work." Feldman, in advocating the tannin process for dry work, states that he has found gelatine very valuable in connection with it for cleaning the tannin solution. He adds a few drops of solution of gelatine, which causes a whitish precipitate, after which the tannin solution is to be filtered-Archiv. Mr. M. H. Harrison, writing in a photographic contemporary, says: "Some time ago, the publication in the Engineer of the difficulties in the way of getting perfectly clean glass tubes for standard barometers at Kew Observatory, drew forth a letter from a professional silverer of glass plates, who said that a weak mixture of hydrofluoric acid and water is the most perfect solution obtainable to give with certainty a chemically-clean surface to glass.". The hygrometer shows a decided increase in the humidity of the atmosphere this morning, and barometrical pressure is slightly decreasing; although only a very slight fall is observed in the mercurial column, yet its tendency has been to fall since the 29th, and doubtless is a precursor of coming rain. The wind is at present northerly by east, which generally causes the barometer to read high, and is seldom at this time of the year accompanied by rain; but from the increasing humidity of the atmosphere this morning, probably a change in the direction towards southward will take place, and rain follow. Should, however, the wind continue in its present quarter, there cannot be much rain. To Correspondents. EBENEZER.-Negretti and Zambra's, Fleet-street. RECEIVED. Once a month," by our Gossiping Photographer; "An Operaglass Camera," by E. B. Fennessy; "A Tour round the coast of Antrim;" Gossip from America," by J. H. Wills; and communications from J. Solomon, E. Lockyer, S. W. Beal, H. C. Lee, D. Winstauley, &c. 44 LANCASHIRE.--We do not see how the pocket camera you mention can be cheaper. The labour in its making is really as much as is required for manu facturing a larger instrument, and the difference being only in the quantity of material employed, cannot be of any material importance. Lancashire says he don't see "how Jack Blunt' could expect Mr. Smith to be aware of the existence of a pocket camera manufactured in Birmingham, and, so far as he knows, never advertised either in the daily or in the photogra hic papers." GRACIOUS GOODNESS, commenting on a letter in or last, sigud Alfred Butler, says, "If any further evidence of the Bumble-like tone of mind displayed by a certain person,' in his reply to a correspondent, were wanted, it might be supplied by another reply which was immediste y above that we quoted in our last, and in which the awful beadle-like threat of branding some one, not with his crimes or even his follies, but with his misfortunes, is held out!" ACID.-The best way of copying a carte-de-visite or small photograph is to pin it down to a flat board wih drawing pins, and take a negative of it in the usual way. Recollect, however, to have the front of your camera quite parallel with the board, otherwise there will be distortion or foreshortening of the image. Use, if you prefer it, a compound lens and a small stop, and give a long exposure, unless the light is very intense; or you may use a single lens. CAMERA PARVA.--We have never seen, nor expect to sec, a lens that does not require focussing for very near and distant objects. Your 2-inch focus lens, however, when once accurately adjusted for general landscape, will require no more focussing for a similiar class of subjects. Your best plon to fix that focus is to first focus on the ground glass with a magnifying glass, and tak a negative; then move out the lens, say about 1-24th of an inch, and take another. Finally move the lens for the same distance, within the visual focus, and take a third negative-all without moving the camera from its pos tion. Compare the sharpness of the three negatives with a magnifying. glass, and when you have found the best, mark that exact distance between the plate and back lens on the camera, for a future guide. Afterwards you have only to look on the ground glass to see that your picture is in proper position, without the bother of focussing, which is often troublesome and sometimes hardly possible in a very dull light. EDWARD HORSWILL.-We shall be very glad to see the photographs. The greater the variety of picturesque localities we can point out, through our illustrations and rambles, the better. Thanks. LUX OBSCURA.-Hardwich's Manual will elucidate the obscurities for youat least as far as they have yet been illuminated. Your fanciful ideas have no facts to recomend or support them. Without such, we put no faith in the electric theory of the action of light on iodide of silver. JOSEPH BRAMSTON.-. Photo-lithographs would not answer our purpose. An ordinary lithographic stone will only give a certain number of good impressions, and the cost of preparing several stones would be too great. 2. The Anastatic printing process was introduced in 1845. It was introduced by a company and promised to do all that the graphotype process now does. I was. however, by no means the first plan of the kind. We forget the exact details of the process, but we know the drawing was transferred to zine, and the parts unprotected by the lines were acted upon by acids. The drawing was made in lines on any well-sized paper with a common pen, and transfer. ink, similiar to that used by lithographers, but prepared by the company: which ink was said to have the peculiar property of not spreading or losing its sharpness under the pressure by which it was transferred to the zinc. Why it was not commercially successful and like many other similar processes died out is a question we cannot answer. 3. M. Dulo's process of engraving in intaglio and in relief was as follows:-The drawing was made in lithographic transfer. ink, on, or transferred to, a plate of silvered copper. The plate was then coated thickly with iron by the galvanic battery. The iron is, of cour e, only deposited on the parts untouched by the drawing. This done, the ink is cleaned off with benzine, and the lines appear in silver on a ground of copper; mercury being then poured over the surface, adheres only to the silver lines, and at once gives them relief. A mould is brained from this, and when an electro deposit of copper is secured upon it, the plate is ready for the printer. If a block for surface printing is required, the copper plate, on leaving the artist's hands, receives a coating of silver, and on cleaning off the ink, the lines appear in copper on a silver ground. The copper is then ox dised, and the above operations carried out. There were some improvements on this process afterwards introduced, but we have not the space to devote to them nor the time to hunt up the records thereof just now. If you desire them for any special purpose, we will, however, give them in our next. PRUDENCE sans FEAR. In a letter just to hand, says: "Sir,-I agree with you in your estimate of photographers as a class, and your comment upon my letter is singularly applicable, inasmuch as in each of the cases I named, the clique' were really the parties referred to. Did you see your contemporary's reply to Brick Wall P We did, of course, see the said reply, and at once concluded that the writer was neither a " Wall" nor a " Brick," and that his statements merely illustrated "Wa ner s long range." We occasionally, as a matter of speed and faith, have ordered an article to be put in tipe which, on reading, we have prom tly decided should be put out of type, and we have also had drawings executed from photographs for this journal, which have never been engraved. In either case we have been influenced by the same consideration, viz., unsuitability. "Brick Wall" has no legitimate cause of complaint. On reading "The Wet C llodion Process in 1868," In the same contemporary, June 19th, we thought had that paper also been put out of ty. e, or, as the printers say, distributed by order of the editor, its readers would surely have been benefited. It would have been better to sacrifice the co-t of "setting up" an article, than the time and parience of numerous readers, and it might also in the end prove cheaper. By such means we hope to preserve our reputation. See Once a Month. GEORGE JAMES HOLLAND-You will discover the information you requrie in our advertisement columns. glazing photographs with oil colour, is one given us by a photographic co ou ist some little time since. It is as follows:-"Place a quarter of a pound of fresh lime in a quart of water, to stand all night, then pour off, without sediment, in a bottle, and cork it, adding a quarter of a teaspoonful of powdered sugar of lead. Mix well on the palette a portion of this with an equal quantity of linseed oil, and the same of mastic varnish, continuing to mix well. It will set like megylp, is a good dryer, and is said to be the best preserver of colours, and never to turn yellow. To simply glaze a photograph with the ordinary medium or megyip, is to insure its turning yellow very quickly. JOHNES.-Perhaps the medium you have heard of as specially suitable for H. D. Declined with thanks. The article is not suitable for our columns. W. G.-Size the engraving first, say with gelatine, and then give it a smooth, even coat of paper, or any other colourless varnish. ETONIAN. We have an article on the subject already in type, which has been repeatedly excluded for want of space. LUCY B.-We know nothing of the motives the trustees may have had, and speculatio in that direction would be altogether useless. Your womanly indig ation, intensified by the remembrance of one so dear to you, who suf fered from the diseases which killed poor Goddard, and whose feebleness and sufferings, even when surrounded by such care and comforts, you will never forget, prompt you to utter rather more than we should feel justified in publishing, although we are quite of your opinion. We think with you, that the statements of Dr. Bird, as given in Mr. Hughes's letter, "are very extracruinary, and ought to be explained." G. CLARKE. We have heard much of late concerning a proposed new photographic society, and a gentleman who is active in the matter, informed us last week that he would shortly place before us a list of nearly two hun dred names signed by gentlemen willing to become members of it. If we receive that list we shall announce something definite. A BRAN NEW PHOTOGRAPHER.-You could select nothing better than the wash-leather, but you should have prepared it for use in a different way:First soak it for twelve hours in a cold and strong solution of washing-soda. This destroys the oil in the skin; then wash in many changes of water, wringing out the skin between each change, until the expressed water runs quite clear. Dry in a cool place. Observe hot water must not be used, because it would turn the skin into a kind of gine. If the skin is hard after drying, beat it with a wooden mallet on a clean table. G. S. O. -We are afraid your collodion on is now quite unfitted for portraiture It may still do excellently well for copying. 2. Use your triplet instead of the single lens. ARTIST.-1. We may shortly devote a paper to the questi n of Camera versus Pictorial Perspective, wherein we shall combat the views to which you call our attention, and show, we think, that they are erroneous. 2. About tairteen or fourteen years ago, Mr. H. Fry recommended the addition of gutta-percha to collodion, and stated that he found the sensibiliy materially increased thereby. LONDON, JULY 10th, 1868. APPENDIX TO PRACTICAL DETAILS OF THE DRY BROMIDE PROCESS, 兆 BY MAJOR RUSSELL. WAS, I think, wrong when I recommended some of the developing liquids to be used from common dropping-bottles; they answered well in my hands for some time, but at last several plates prepared with different collodions were, after development, found to be badly affected by small insensitive spots; those plates on which the developer had been longest at rest were the worst; this pointed to the cause of the spots. The dropping-bottle from which the bromide was used was nearly empty, and a deposit at the bottom was disturbed by tilting the bottle. The spots were got rid of in the next plates developed by using all the liquids from pneumatic dropping-bottles. If common dropping bottles are used, they should be kept nearly full, and the lips wiped before beginning to use them; but the pneumatic bottles are safer; the points of the tubes should be ground away till they do not reach within inch of the bottoms. Taking the air monia and bromide solutions from common phials would answer equally well, but would be rather more troublesome. Whatever plan is adopted, the number of drops to a drachm of each liquid should be counted, that the right proportions may be used; the solutions should always be filtered when made, and be put into tall bottles, that any solid matter may subside before decanting into the bottles from which they are to be used. Solid particles in the ammonia solution may make black spots and comets; in the bromide solution, insensitive spots. Some more experiments have been made to ascertain how weak a bath can be used with bromised collodion. With good manipulation, streaks will not be formed, but the bath must be strong enough to convert the bromide in the film. The exact strength necessary for this depends on the quantity and proportion of bromide in the collodion, and also a little on the quality of the pyroxyline; therefore it may be well to describe how it may be known when the limit has been passed of weakness of bath with any collodion. The first symptom of too weak a bath is the appearance by reflected light on the film, when dry, of clouds whiter than the rest. These clouds are caused by the bromide of silver being too much on the surface of the collodion; they seem to be liable to fog in development. If the limit thus indicated be not passed, and streaks are not formed by bad manipulation, extra time in the bath will have quite as good effect as more nitrate of silver. Collodion containing in each ounce 4 grs. of cotton for the wet process, and 12 grs. of bromide of cadmium, will, in my hands, generally work well in a 45-gr. bath, but it forms clouds in a 40-gr. bath. A day or two ago some plates coated with the collodion just described were excited in a 50-gr. bath for thirty minutes; they were as sensitive as any I ever prepared, and soon attained printing density without any addition to an alkaline developer of moderate strength. Mr. Sutton is certainly mistaken in his new theory of the bromide process (p. 265), as he will find out if he perseveres with it. A very strong bath is not necessary; it converts more bromide in a given time than a weaker one; but if Mr. Sutton had kept his plates thirty or forty minutes in his 50-gr. bath, they would have given as much or more intensity than the same collodion kept ten minutes in a 60-gr. bath. Acid is not necessary in the bath, but it makes the double decomposition more energetic. A neutral or slightly alkaline bath acts precisely like an acid one containing less nitrate of silver, and therefore if both are of the same strength, the plates should be kept longer in the former; if this be done, there will be no difference in the quality of the plates, whether the bath be acid or not. Vol. I.-No 23 Mr. Sutton's plates would not intensify because the light could make no impression below the surface, the interiors of the films being kept insensitive by a large quantity of unconverted bromide. Intensity cannot be produced by an alkaline developer unless the effect of light has some depth. I have worked with extremely opaque bromide films, but never found that any degree of opacity diminished sensitiveness. Mr. Sutton's plate, which had been kept twenty-four hours in the bath, must have had all its bromide converted; and when this is the case a plate will not produce a picture at all, at any rate with a developer unrestrained by soluble bromide. Besides, when an excess of nitrate of silver has passed through the film, the bromide of silver may perhaps be in a wrong state of division Bromide of silver after exposure to light is reduced to metallic silver by alkaline pyro. A description of experiments which proved this was sent by me and published (I think in July, 1865) in a journal of which Mr. Dawson was then one of the editors; the specimens are, I think, still in his possession. The parts of the film which had been acted on by light and developed, were dissolved away by dilute nitric acid, making transparent patches surrounded by a thick film of unaltered bromide of silver. Organic matter doubtless plays an important part, but it need not be an organic silver compound. If simply washed and dried, organic works much better than inorganic collodion, but with tannin the most inorganic collodion works as well, and I think better, than the most organic. It certainly works far better with tannin than organic collodion only washed and dried; this proves that tannin is a more effective stimulator of bromide of silver than any organic silver compound in the collodion. Albumen as a preliminary coating is not well suited for alkaline developers, because alkalies act on it and make it blister. The characteristic albumen colour is likely to be given to a negative by albumen below it, though not reached by the nitrate of the bath; for the same effect is produced when albumen is applied to the surface moved. As before stated, I have repeatedly tried collodion after all the nitrate of silver has been chemically recould detect the slightest difference, except that the oil with and without 1 drop to the oz. of castor-oil, but never makes the collodion less brittle and contractile. Common water, if used as the first washing water after excitement, makes smears of insoluble silver salts, which show as dull marks on the film when dry; the harder the water, the worse; but every succeeding plate washed in the same water will improve, until at last the water will work as well as distilled water. When distilled or pure rainwater cannot be procured, the best plan would be to boil hard water to throw down the chalk, and then to add solution of nitrate of silver cautiously, until the salt in the water is part precipitated. At p. 53 of this journal, a description was given of a trial of Mr. Gordon's new honey process. The trial has lately been repeated in the same manner as before with the collodion and honey which Mr. Gordon uses. This time the results were different; the collodion was bromoiodised, and so inorganic that it would give only a faint image of the high lights after being dipped in dilute albumen, washed, and dried. Twenty minims of honey to the oz., dried on, produced as nearly as possible the same effect as 1 gr. to the oz. of tannin, washed off again, in promoting sensitiveness and intensity; when both agents were applied, the good effects of both were obtained. It was noticed that the tannin produced its full effect, as far as it went, making a sharp line; the effect of the honey faded away towards the upper edge, when it had been diluted and washed down by the moisture soaking from the upper part of the film. This shows that, to have much effect, the honey must be left on. The difference in the result of this trial and that of the former one is probably due in part to the nature of the |