Suche löschen...
The photographic news
- Bandzählung
- 6.1862
- Erscheinungsdatum
- 1862
- Sprache
- Englisch
- Signatur
- F 135
- Vorlage
- Hochschule für Grafik und Buchkunst Leipzig
- Digitalisat
- Hochschule für Grafik und Buchkunst Leipzig
- Digitalisat
- SLUB Dresden
- Lizenz-/Rechtehinweis
- Public Domain Mark 1.0
- URN
- urn:nbn:de:bsz:14-db-id1780948042-186200003
- PURL
- http://digital.slub-dresden.de/id1780948042-18620000
- OAI-Identifier
- oai:de:slub-dresden:db:id-1780948042-18620000
- Sammlungen
- Fotografie
- LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
- Bemerkung
- Seite 1-72 fehlen in der Vorlage. Vorlagebedingter Textverlust.
- Strukturtyp
- Band
- Parlamentsperiode
- -
- Wahlperiode
- -
- Bandzählung
- No. 217, October 31, 1862
- Digitalisat
- SLUB Dresden
- Strukturtyp
- Ausgabe
- Parlamentsperiode
- -
- Wahlperiode
- -
-
Zeitschrift
The photographic news
-
Band
Band 6.1862
-
- Ausgabe Ausgabe 73
- Ausgabe Ausgabe 85
- Ausgabe Ausgabe 97
- Ausgabe Ausgabe 109
- Ausgabe Ausgabe 121
- Ausgabe Ausgabe 133
- Ausgabe Ausgabe 145
- Ausgabe Ausgabe 157
- Ausgabe Ausgabe 169
- Ausgabe Ausgabe 181
- Ausgabe Ausgabe 193
- Ausgabe Ausgabe 205
- Ausgabe Ausgabe 217
- Ausgabe Ausgabe 229
- Ausgabe Ausgabe 241
- Ausgabe Ausgabe 253
- Ausgabe Ausgabe 265
- Ausgabe Ausgabe 277
- Ausgabe Ausgabe 289
- Ausgabe Ausgabe 301
- Ausgabe Ausgabe 313
- Ausgabe Ausgabe 325
- Ausgabe Ausgabe 337
- Ausgabe Ausgabe 349
- Ausgabe Ausgabe 361
- Ausgabe Ausgabe 373
- Ausgabe Ausgabe 385
- Ausgabe Ausgabe 397
- Ausgabe Ausgabe 409
- Ausgabe Ausgabe 421
- Ausgabe Ausgabe 433
- Ausgabe Ausgabe 445
- Ausgabe Ausgabe 457
- Ausgabe Ausgabe 469
- Ausgabe Ausgabe 481
- Ausgabe Ausgabe 493
- Ausgabe Ausgabe 505
- Ausgabe Ausgabe 517
- Ausgabe Ausgabe 529
- Ausgabe Ausgabe 541
- Ausgabe Ausgabe 553
- Ausgabe Ausgabe 565
- Ausgabe Ausgabe 577
- Ausgabe Ausgabe 589
- Ausgabe Ausgabe 601
- Ausgabe Ausgabe 613
- Register Index 619
-
Band
Band 6.1862
-
- Titel
- The photographic news
- Autor
- Links
- Downloads
- Einzelseite als Bild herunterladen (JPG)
-
Volltext Seite (XML)
518 THE PHOTOGRAPHIC NEWS. [October 31, 1862. ON THE CONSTITUTION OF THE DARKENED CHLORIDE OF SILVER. BY JOHN SPILLER, F.C.S. In the course of some experiments on the action of phos phorus upon metallic solutions, I was incidentally led to observe a chemical reaction, which appeal's to throw some light upon the nature of the decomposition effected by the sun’s rays on the white chloride of silver. If a current of phosphoretted hydrogen gas ’to conducted through an aqueous solution of chloride of mercury, there is formed an orange yellow precipitate of somewhat doubtful constitution, but containing the elements phosphorus, chlorine, and mer cury, in the proportion required by the formula PHga, 3 Hg Cl; and described in Gmelin’s “ Handbook of Che mistry ” under the name of “ phospho-chloride of mercury.” This product having been collected on a filter, and purified by washing, was transferred to a test tube, and acted upon by a neutral solution of nitrate of silver, when the compound immediately became white, and underwent a succession of changes in colour, exactly corresponding to those observed when the white chloride of silver is exposed to sunshine; and by varying the conditions of the experiment—using the silver in larger or smaller amount, and employing a gentle heat—it was possible to control the rapidity of the change, and to produce the slight variations of tint, violet, sometimes tinged with red, at other times with blue, which are con stantly noticed in practical photography. With regard to the chemical changes accompanying this alteration of colour, it is probable that the first action con sists merely in the conversion of the chlorine in the yellow mercury compound into white chloride of silver, the mercury at the same time entering into solution; a moment later the reducing action of the phosphorus in the compound begins to be exerted upon the remaining nitrate of silver, the result of which is, that particles of metallic silver are formed, and gradually accumulate within and throughout the entire mass of the white chloride, and to the production of this metallic precipitate is attributed the darkening and general altera tion of colour observed during the progress of the experi ment. If this explanation of the phenomenon be correct, there is a well sustained analogy in regard to the constitu tion of the darkened chloride of silver, whether prepared under the reducing action of sunshine, or by the power of reduction originating in the phosphorus contained in the mercury salt employed. In confirmation of this view, it may be stated that the violet substance produced in the manner indicated becomes grey and metallic by treatment with ammonia, hyposulphite of soda, or cyanide of potassium; and with nitric acid and other chemical reagents behaves exactly like the product formerly examined by me, and de scribed in a contribution to the Philosophical Magazine for March, 18G0. Royal Arsenal, Woolwich, October 28, 1862. Uhe Juternational Gxhibition. BRITISH PHOTOGRAPHIC DEPARTMENT— APPARATUS. We find the last days of the Exhibition approaching before the amount of time and space at our disposal has allowed us to complete our notices. We now hasten to proceed with further brief remarks on the apparatus. Messrs. MLean, Melhuish, & Co. (3,120), exhibit some excellent samples of the especial apparatus for which they are known, such as the Metal Camera, giving a maximum of rigidity, lightness, and durability; the Universal Objective, &c., &c. Especially deserving of notice is the “ Simulta neous Camera,” the conception we believe of Lieutenant- Colonel Shakspear. This is a square trunk camera, fitted with four lenses for card portraits. Its specialty consists, however, in the use of a fifth lens which acts as a finder. Bj the use of such a lens the sensitive plate may be placed in situ with the slide drawn, and all ready for exposure at a moment s notice, the right time being ascertained by the aid of the finder, with which the focussing of moving objects is alsoeffectedi the finder having, of course, the same focus as the other lenses, and the camera being so arranged that the focussing of one regulates all. For instantaneous effects, andfor por traits of children, &c., the use of this application will be manifest. Mr. Meagher, Coppice Row, has a very well arranged dis play of photographic apparatus, chiefly consisting of cabi network. Mr. Meagher received his allotment of space at so late a moment that his name does not even find a place in the Catalogue; his contributions, begun and finished within a few days, were moreover placed immediately beneath the skylight, subjected to a heat which we hope apparatus has rarely to withstand even in the tropics. The perfect condi tion, however, of every article at the present moment illus trates their suitability for the Indian climate, for which a good deal of the apparatus exhibited is designed. A large trunk camera of Spanish mahogany, is a very handsome piece of cabinet work, and would be an ornament to any operating room. It has all the modern appliances of swing back, endless screw, &c., and having a focal range of from 0 inches to 30 inches, is available as an excellent copying camera. A new binocular stereo camera, manufactured by Mr. Meagher, and designed some time ago by ourselves, is excei dingly complete and convenient, and having now used for - mi dl mad are well satisfied th ■ • , ns on ■ ■ । mipments possible foi ; er. It is arranged so • 1 ictures, or views ini ■ ■ tial partition and ex: it n inche ' 10 inches, admit- tin. ■ oi ' short focus, and a single leris l.” • or lar views. In our own we use a Dallmeyer’s, No. 1, triple, and a pair of his stereo lenses, which form a very complete equipment. The camera has a bellows body, and hinged tail board, which folds up and reduces the camera to the smallest compass. It has also swing back, screw focussing adjustment, &c., stereo inner frames, and card portrait inner frames, &c., and when packed up with three double backs in the leather case pro vided for it, forms a convenient and very portable parcel for the hand. We subjoin an engraving of the camera extended and packed up. Brass bound and other Kinnear cameras with modern im provements, a folding binocular stereo camera, which may easily be carried in the pocket, carte de visiie cameras, revolving cabinet stereoscopes, various ornamental cases for stereoscopic slides, water tight baths, stands, printing frames, and various minor matters, complete a very hand some case of photographic cabinet work. Messrs. Murray & Heath (3,128), have a fine display of apparatus of the very best quality, and designed with much judgment to meet the various wants of photographers. Pro minent in their case is a noble copying and enlarging camera, with double bellows body, and extending severa feet. It has a screw adjustment working from either en<. A graduated scale is attached which enables perfect focus o be obtained for any degree of enlargement with a so u c accuracy, without even looking at the ground glass. 0c is the graph ment. and es quire spare ; enume earner; ness t< avoid 1 stereos forms, outside camera single 31 to lenses, genioui illumir Bent f scope ft telescoy instead Smartt’ And wit Wul a Plates t vith le fess cc bath, w ( Vhen it Bequisit , My th Sotplet •Me ad ving b Minan H as I Bprove “splay I " Ot 1 a) i Ehese c i J field I , hovel Sticles < Sin Vthegl the fo kap Chore Bplaini "shave 6‘photi L % rece ibeen By wl a BPerati L lot o it «»nos BBDecess ftre 1 aS t 4Be was Wtioi Ni have V8h2gi p 8 hi VUhe r
- Aktuelle Seite (TXT)
- METS Datei (XML)
- IIIF Manifest (JSON)