The Chemical Gazette, Band 21844 |
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acetic acid action added æther affords albumen alcohol alkalies ammonia analysis anhydrous antimony aqueous atoms barytes becomes blue boiling brown carbonic acid caustic potash cent cerium chemical chloric acid chloride cold colour colourless combination composition compound contains copper crystalline crystals cyanide decomposed decomposition deposited dilute disengaged dissolved distilled dried employed equiv evaporation excess experiments extract fibrine filtered formed formula grms heat hydrate hydrochloric acid hydrogen ignited insoluble iodic acid iodide iodine iron lanthanium lime liquid liquor madder magnesia maleic acid mass matter mercury metallic mixed mixture muriatic acid neutral nitrate nitric acid nitrogen obtained odour oxide oxygen peroxide Pharm phosphuret portion potassium powder precipitate prepared produced protoxide pure residue resin salt separated silver small quantity soda soluble in water solution substance succinic acid sugar sulphate sulphuretted hydrogen sulphuric acid temperature tion titanic acid tube urine vapours washed yellow zinc zircona
Beliebte Passagen
Seite 184 - I introduce a current of steam by a pipe, so that it passes through the perforated plate and the madder which is upon it. During this process, which occupies from one to two hours, a substance is produced of a dark brown colour approaching to a black.
Seite 507 - ... enough. 5. To protect the plate from the effects of wear, produced by the operation of printing, the following process is employed : — the surface of the plate is covered with a very thin coating of copper, by means of the electrotype process, before submitting it to the operation of printing ; and when that pellicle or coating of copper begins to show signs of wear, it must be removed altogether, by plunging the plate in ammonia, or in a weak acid, which, by electro-chemical action, will dissolve...
Seite 183 - A quantity of stones or gravel is placed upon the bricks, and over the stones or gravel common wrappering, such as is used for sacks. Below the bricks is a drain to take off the water which passes through the filter. In a tub adjoining the filter is kept a quantity of dilute sulphuric acid, of about the specific gravity of 105, water being 100.
Seite 55 - ... pictures taken on calotype and other photographic paper, which has been prepared with a solution of nitrate of silver, by plunging the picture into a hot bath, composed of hyposulphite of soda, (or any other soluble hyposulphite,) dissolved in ten times its weight of water, and heated to nearly the boiling point; the picture should remain in the bath about ten minutes, and be then washed in warm water, and dried. By this means, the picture is rendered more permanent and transparent, and its lights...
Seite 295 - The papers are prepared in the most simple manner, and may be kept ready by the tourist until required for use. They require no preparation previously to their being placed in the camera, and they can be preserved until a convenient opportunity offers for bringing out the picture, which is done in the most simple manner, with a material which can be anywhere procured. Anxious to give the public the advantage of this process during the beautiful weather of the present season, I have not waited to...
Seite 509 - ... solution, and heating it by means of a spirit lamp, until, by evaporation, the potash becomes in a state of ignited fusion. By this means the grain is finer, but the white parts are more liable to be attacked. Last operation of biting in. — This operation requires some of the re-agents before named, and also, 1. A siccative ink, made of linseed oil, rendered very siccative by boiling it sufficiently with litharge; it may be thickened with calcined lamp-black. 2. An electrotype apparatus, and...
Seite 508 - ... the normal acid. When the plate has been immersed a few seconds in the acid, it is taken out by means of the glass holder, taking care to keep it as much as possible covered with the solution, and it is immediately placed horizontally upon a stand, and as much acid as the plate can hold is poured upon it from the bottle ; it is then heated with a spirit-lamp, but without attaining the boiling point.
Seite 436 - ... a pearly transparent appearance. The whitening and cleaning up of. the picture, by this process, is far more beautiful than by the ordinary method of fixation by a deposit of gold. A small portrait fixed in this way, more than a year since, remains unchanged...
Seite 254 - ... on which it is to be deposited, as in the case of wax, or by coating the surface thereof. Any of the known preparations of wax may be treated in this way; but the one preferred by the patentee is composed of from 6 oz.
Seite 437 - In one instance a clear and beautiful ruby colour was produced, limited in a well-defined manner to the drapery, while all other parts were green. To succeed well in the first process, viz. that for fixation and the production of the pearly appearance, the impression should be carried as far as possible without solarization, the solution of the hyposulphite of soda should be pure and free from the traces of sulphur*, the plate should be carefully washed with distilled water, both before and after...