The Dictionary Of Photography

A True Historic Record Of The Art & Practice Of Photography 100 Years Ago.

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Anthotype                                                         Antiseptics
Anthotypea flower). An old process yielding ex-
ceedingly fugitive prints, depending for its principle upon the bleaching action of light upon chlorophyll and other vegetable juices, when the same are spread upon paper and exposed under a negative. More recently Messrs. A. and L. Lumi£re have sug-gested to reproduce a coloured transparency by exposing under it a sheet of paper prepared with a mixture of fugitive colours, as for example, quinoline blue, curcuma, and a rapidly fading red. Attempts to fix such images have been unsatisfactory, as metallic bases which will unite with the colouring substances alter the tint.
Anthrakotypecharcoal or coal).
A process for reproducing in carbon or pigment such subjects as sh ow little or no half-tone. Paper is coated with plain gelatine, say i to 8 or 10 of water, and when dry is sensitised in a bi-chromate bath - say i part of potassium bichromate in 20 of water. The paper is now exposed under a positive, soaked in water, blotted off, and then dusted over with the pigment, which adheres to those parts where the gelatine was protected from light, and is consequently swelled by the water. Careful sponging now removes all excess of pigment. Tracings may be repro-duced witrl remarkable perfection by the anthrakotype process.
Anthraphotoscope. A kind of photographic peep-show, backgrounds and figures being marginally mounted on glass discs, by suitably turning which various combination scenes can be produced - as, for example, a play in dumb show.
Antihalation Papers and Mixtures. See Backing Plates.
AntiplanatI lead
astray). A term applied to a particular type of lens constructed bv Steinheil. (See Lens.)
Alltipyr. A name under which Formalin (q.v.) is sometimes sold.
Antiseptics. Substances which prevent putrefactive change. Phenol or carbolic acid and salicylic acid are frequently used in gelatinous mixtures. Alcohol, if present to the extent of about 20 per cent., effectually prevents the putrefaction of most organic mixtures.