the "white" tissue, upon a coloured transfer paper, prints in any colour or tint can be obtained by the use of one tissue. The "white" tissue is very convenient when a print is to be transferred to a dark surface - for example, a black panel form-ing part of an article of furniture.
The Mariotype Carbon Process and the Ozotype Carbon Process. In these methods of working, the transfer paper or ultimate sup-port is sensitised and exposed, after which it is brought into contact with the pigmented organic matter, this latter being thus rendered insoluble locally or over the exposed parts. (See Mariotype and Ozotype.)
Carbonates. A class of salts largely used in photography and industrial operations. After marble and chalk, which are car-bonate of calcium, the most familiar carbonate, and most used in photography, is that of sodium (washing soda), Na2C03, ioH20. The white powder ordinarily sold as carbonate of soda by the pharmaceutical chemist is a bicarbonate, and is not used in ordi-nary photographic operations. It takes its name from a period when it was regarded as the normal carbonate, the salt now looked On as the normal carbonate being then called the subcarbonate.
Carbonised Plates. A plate of metal on which carbon has been deposited, or a plate of compact carbon such as is used for batteries, if moistened with nitrate of silver and exposed to light gives an image in white reduced silver.
Caricatures, Photographic. Among the most common methods of making these may be mentioned successive expo-sure against a black background, the use of painted or sketched screens in front of the sitter, and photographing the reflection from a curved mirror. (See Polypose, Spirit Photography, and Anamorphoscope.)
Carrier. A framework of wood used in the dark slide to enable the operator to use a smaller plate than the full size.
Carte de Visite. A once very popular size of the professional photograph, measuring about
Cartridge. Dry photographic chemicals are often put up in cartridge form for the use of tourists, and home-made cartridges, made to a special size, are often convenient, and may be re-filled