Cap

A loose leather cover for the lens.

Caramel

Carbolic Acid

(See Acid Carbolic.)

Carbon

C.

Carbon for photographic purposes is usually prepared from lampblack. Is very stable. The basis for the carbon process, which is the most permanent process known.

Carbon Disulphide

CS2.

Bisulphide of Carbon. Clear, colorless, neutral liquid. Highly refractive and inflammable. Sharp, aromatic taste. Peculiar odor. Soluble in alcohol, ether, chloroform, fixed and volatile oils.

Carbon Paper. Carbon Tissue

Pigmented gelatin coated on paper. Can be readily sensitized with potassium bichromate.

Carbon Process

A printing process in which bichromated gelatin and carbon, which form a pigment, are coated upon paper. The print is developed from the back with water of different temperatures; the parts exposed to light have been rendered insoluble, the unexposed portions only are washed away. The single and double transfer processes are fully described in the general instruction given in the library.

Carbonate of Ammonia

(See Ammonium Carbonate.)

Carbonate of Potash

(See Potassium Carbonate.)

Carbonate of Soda

Carbonic Acid

Carboy

A large glass bottle enclosed in a box or basket. Used principally for holding corrosive acids.

Caricature

A photograph in which the natural characteristics of a person, or objects, are distorted or exaggerated.

Background Carrier

A frame for supporting a background

Carte-de-Visite.

A small photograph about 2 1/2 x 4 1/8 inches in size

Cartridge

A small case of metal, glass or paper in which photographic compounds, in their dry state, can be placed for convenience. The chemicals are put up in this form for toning, fixing, developing, intensifying, reducing solutions, etc.

Cement for Cast-Iron

A good cement for stopping holes in castings, etc., is made by mixing the following chemicals with water into a thick paste. Always mix fresh before use.

Sifted Cast-Iron Filings...........................

10 ozs.

Sal Ammoniac (powdered).....................

2 drms.

Sulphar.....................................................

1 drm.

Castile Soap

A fine, highly purified soap. When perfectly fresh, yellowish-white in color. Used to wax prints before burnishing by rubbing the surface of the print with a piece of flannel which has previously been rubbed on the soap.

Castor Oil

A thick, oily liquid. Soluble in ether and alcohol; insoluble in water. Used in the preparation of collodion and varnishes to make them tougher; also in rendering paper, or paper negatives, translucent.