The photographic news

• Bandzählung: 7.1863
• Erscheinungsdatum: 1863
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
• URN: urn:nbn:de:bsz:14-db-id1780948042-186300004
• PURL: http://digital.slub-dresden.de/id1780948042-18630000
• OAI: oai:de:slub-dresden:db:id-1780948042-18630000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

6 is coagulated by heat; but I have noticed that, by this simple desiccation, it does not dissolve as ready as albumen fresh from the egg, which compels me to conclude that any degree of desiccation weakens the faculty of coagulation. From this it results that the passing a hot iron over paper covered with dried albumen produces no effect, and that the presence of water is essential to obtain coagulation. In all probability, a minimum quantity of water suffices to pro duce this phenomenon ; as to the paper, if already dry, it is sufficient to place it in a cellar, or other damp place, for a time, for the albumen to become coagulated by the passing of a hot iron over it. To render albumen in the dry state (insoluble, we must have recourse to chemical actions. Dry albumenized paper immersed in absolute alcohol, abandons its albumen to water as soon as the alcohol is evaporated; concentrated gallic acid no longer producing any effect on it. It is different with the metallic salts : the salts of silver and of mercury, for instance, produce insolubility. With the albumen ized papers in a dry state this is an essential point, as they must always be sensitized on the silver bath before they can be used, only it would be preferable for the albumen to be coagulated in advance ; and if, heretofore, the passage of a hot iron over the dry paper was in reality without effect, it is now certain that on performing the same operation at the proper moment, that is, while the coating of albumen is still moist, or is rendered so by exposing the dried paper in a damp place, an excellent effect will result, which abso lutely prevents the separation of the albumen, which so fre quently spoils the silver baths. For the preparation of albumen on glass, it will be also useful to take this experi ence into account by submitting the coated plates to a degree of heat suitable to coagulate the albumen, before they become completely dry, so as not to take this trouble in vain, inas much as the introduction of albumen into the bath is much more mischievous in this case than in the other. Albumen is an organic substance, the complexity of which has remained hitherto impenetrable to chemical investiga tion : in all probability its molecule is composed of a great number of atoms, (since sulphur forms a part, yet cannot be separated, because its proportion is so small,) then its weight is considerable ; and it is this that induces me to say that a very small proportion of water suffices to promote its coagu lation. This useful proportion is actually disengaged only when the desiccation has arrived at its last limit, and we can be certain of succeeding in coagulation only when the paper appears not quite dry to the touch. [The amount of moisture necessary to secure the condi tions for coagulation is an interesting subject for inquiry. Mr. J. W. Osborne recently remarked to us, that in the pre paration of his photolithographic transfer, he has observed, that when the paper, coated with gelatine and albumen, was floated on boiling water, face upwards, no coagulation of the latter took place at boiling heat until the whole had become thoroughly permeated with moisture, and that, by observa tion and experience only, could the proper time be deter mined.—Ed. P. N.] PHOTOGRAPHY IN THE POLICE COURT. Photography and photographers have recently been figuring in the police court. Besides the recent copyright infringe ments, there have been, within the last week, two or three criminal cases, which we give as reported in the daily papers. The first was before Mr. Elliot, at Lambeth, and stands as follows: — Robbery at the Crystal Palace.—George Restall, a young man, who has been manager of the business—in the Crystal Palace—of Messrs. Negretti and Zambra, was charged with stealing thirteen lenses of the value of £60, the property of his employers. Mr. H. Negretti deposed that the prisoner was employed by his partner and himself to conduct their business at the Crystal Palace, at a salary of £3 a week, and about a fortnight since | [January 2, 1863. he came to them and said he had missed as many as nineteen lenses from his stall in the palace, and mentioned the name of a party whom he suspected. He (witness) told him at once to communicate with the police at the palace; but instead of doing so, he gave information of the alleged robbery at Scot land-yard, giving as his reason that the police of the palace were too friendly with the suspected party. Three of the four lenses produced were the property of witness and his partner, and were a portion of those missing. A shopman to Mr. Blizzard, pawnbroker, in the Borough, produced the four lenses, and said that they had been pledged with him by the prisoner, who described them as his own pro perty. Sergeant Palmer, a detective, said that about a fortnight ago he received instructions to make inquiries respecting thirteen lenses stolen from the Crystal Palace. He saw the prisoner on the subject, and in his account about the lenses he said they were safe about three weeks ago, though in his information he mentioned that they had been gone six months. He asked him if he pawned them, or either of them, when he not only positively denied having done so, but de clared he had never been in the shop of a pawnbroker in his life. The prisoner, who denied the charge, was remanded to a future day. On Tuesday last the ease was again heard, when Mr. Sleigh appeared for the defendant, and Mr. Lewis, jun., for the prose cution. Mr. Negretti said that since the last examination he dis covered other lenses missing, and requested a further remand, to give time for tracing the other property, and which, with that produced, was of the value of from £90 to £100. Mr. Sleigh represented the prisoner as a person of high re spectability, and, he felt quite sure, incapable of committing the offence attributed to him, and examined the witnesses at some length, after which the prisoner was again remanded, but admitted to bail. We sincerely hope that at a future hearing Mr. Restall may be able to prove his innocence, as we know him to be a skilful photographer, and should be sorry to think him a dishonest one. The next case was heard at Marlborough Street, before Mr. Tyrwhitt, and stands thus in the report: The Major and the Photographer.— Winter Thompson, photographer, Oxford-street, was summoned before Mr. Tyr whitt for assaulting Major Lister. The evidence of the major went to show that he went to the defendant’s with his wife and child, six years of age, to have the latter’s portrait taken, and there saw a female, who said that if the first portrait taken was not approved of, a second should be taken, there being also a notice up to a similar effect. A portrait was taken, but as the child’s head, owing to the position in which the child was placed, was sunk between its shoulders, he objected, and asked for another; but the artist rudely objected, said it would do very well, and on his going down stairs, declining to go on with the transaction, a man (Mr. Thompson, jun.) rushed out of a door on the left hand side of the passage, and pushed him back, threatening to knock him down. Another man (the defendant) then rushed out of another room and seized him by both hands. The defendant then retired, at his son’s request, and an alteration of a violent nature on the younger Thompson’s part ensued, in the course of which he said that he was justified in detaining him (the major), and taking his life. The cost of the portrait was to be half-a-crown. Mr. Edward Lewis, of Great Marlborough-street, for the defence: The major said that he had been to the Messrs. Southwell’s, the photographers, previously, but was perfectly satisfied with the reception he there met with. Mr. Thompson did not say that if he pointed out any fault ho would do another. He did not wait for the photograph, and only was reluctantly shown the negative. Mr. Thompson, jun., was called as a witness for his father, and said the complainant would not point out any fault in the negative, but peremptorily refused to have the portrait, and re fused to give his name and address, or to pay the 2s. 6d. for it. A young woman named King, in the employ of the defendant, said that the major wished to arrange the child himself,-and would not let the artist do so. Mr. Thompson, jun., did not push him, and Mr. Thompson, sen., rushed out of the room, and said the major should not strike his son. THE PHOTOGRAPHIC NEWS.