A Dictionary of Photography |
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aberration acetic acid actinic added albumen alcohol alkaline ammonia angle atoms becomes boiling bromide called camera carbonic acid centre chemical chloride chloride of silver chromate collodion collodion process colour combination compound contains crystals dark decomposed decomposition deliquescent developer dissolved distilled water effect ether exposed exposure film focal length focus free nitrate gallic acid gelatine glass grains gutta percha heat hydrochloric acid hydrogen inches insoluble iodide iodide of potassium iodide of silver iodine iodized iron lenses lime liquid mercury metallic mixed mixture negative neutral nitrate bath nitrate of silver nitric acid object obtained optical organic matter ounce oxide oxygen paper photographic picture placed plane plate positive potass potassium precipitate prism produced protoxide pure pyroxyline quantity rays refracted removed rendered resin salt sensitive soluble solution spherical aberration stereoscope substance sulphate sulphuric acid surface temperature tint tion transparent varnish washed yellow
Popular passages
Page 350 - In general, the plane determined by an incident ray and the normal to the surface at the point of incidence is called the plane of incidence.
Page 195 - ... one or more sensitive substances in a mixture of various compounds, and shows to a great extent, before such substances have been isolated, in what menstrua they are soluble, and with what agents they enter into combination. Unfortunately, these observations for the most part require sunlight. (8) The phenomena of internal dispersion oppose fresh difficulties to the supposition of a difference of nature in luminous, chemical, and phosphorogenic rays, but are perfectly conformable to the supposition...
Page 208 - Pliny ascribes the origin of glass to the following accident. A merchant ship laden with natron being driven upon the coast at the mouth of the river Belus, in tempestuous weather, the crew were compelled to cook their victuals ashore, and having placed lumps of the natron upon the sand, as supports to the kettles, found to their surprise masses of transparent stone among the cinders.
Page 329 - ... only which have been affected by the light. Thus, if the screen employed be a negative, having the .lights and darks reversed, the print will be a positive, with the lights and darks correct ; and, if the screen be a positive, the print will be a negative. The print may be retained on the surface on which it is first produced, or it may be transferred or printed upon paper or other suitable material, and the operation repeated. I thus obtain a design upon lithographic stone, or other suitable...
Page 17 - Operation.—Development of the photographic trace. When the paper is removed from the cylinder it is placed upon a board, and a saturated solution of gallic acid, to which a few drops of...
Page 211 - Its specific gravity is 19-3. It is so malleable that it may be extended into leaves which do not exceed the one two hundred and eighty-two thousandth of an inch in thickness, or a single grain may be extended over 56 square inches of surface. This...
Page 208 - Moses, we discover glass ornaments in tombs which are as old as the days of Moses. According to Pliny and Strabo, the glass works of Sidon and Alexandria were famous in their times, and produced beautiful articles, which were cut, engraved, gilt, and stained of the most brilliant colours, in imitation of precious stones. The Romans employed glass for various purposes ; and have left specimens in Herculaneum of window-glass, which must have been blown by methods analogous to the modern.
Page 164 - DIAMOND CEMENT. — Soak isinglass in water till it is soft ; then dissolve it in the smallest possible quantity of proof spirit, by the aid of a gentle heat ; in two ounces of this mixture dissolve ten grains of ammoniacum, and whilst still liquid, add half a drachm of mastic, dissolved in three drachms of rectified spirit; stir well together, and put into small bottles for sale.
Page 200 - ... so well that others may be applied over them without degradation. Along with lampblack and gum, it forms a good imitation of China ink. When a coat of ox-gall is put upon drawings made with black lead or crayons, the lines can no longer be effaced, but may be painted over safely with a variety of colors previously mixed up with the same ox-gall.
Page 295 - Enough has now been said about a process which must strike any reasonable person as somewhat trifling and childish, when he considers how many valuable applications of photography remain yet to be worked out.