collodion

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A highly flammable, colorless or yellowish syrupy solution of pyroxylin, ether, and alcohol, used as an adhesive to close small wounds and hold surgical dressings, in topical medications, and for making photographic plates.

Century Dictionary and Cyclopedia

1. n. A substance prepared by dissolving pyroxylin or guncotton in ether, or in a mixture of ether and alcohol. It forms a useful substitute for adhesive plaster in the case of slight wounds. When the solution is applied to the wound, it immediately dries in a semi-transparent, tenacious film, which adheres firmly to the part, and protects the wound or abrasion. With the addition of a small quantity of iodides and bromides. collodion is employed as the basis of a photographic process, called the collodion or wet process. To obtain a negative picture by this process, a glass plate is covered with a film of collodion, which is sensitized by a salt (usually the nitrate) of silver, and the plate exposed in the camera. The latent image obtained is then developed by the application of a solution of iron protosul-phate, water, and acetic acid, and the unprecipitated silver remaining in the film is dissolved by a fixing solution of sodium hyposulphite or of potassium cyanide. To obtain a positive picture, a sheet of paper is laid upon the face of the negative in a frame, the paper having been sensitized by floating on a solution of silver nitrate, or by any other of several methods. The frame is then exposed to light in such a manner that the rays, to reach the paper, must pass through the negative, and the exposure is continued till the tone is sufficiently deep, after which the tint is improved by means of gold chlorid and other salts, and the picture fixed with sodium hyposulphite. Positive pictures may also be obtained direct by the collodion process. Collodion is used also as a water-proof coating in place of varnish, especially to protect lucifer matches from the effects of dampness.

Wiktionary

1. n. a syrupy solution of pyroxylin in alcohol and ether that evaporates on a surface to form a clear elastic film; used in surgical dressings, photographic plates and lacquer paints

GNU Webster's 1913

1. n. (Chem.) A solution of pyroxylin (soluble gun cotton) in ether containing a varying proportion of alcohol. It is strongly adhesive, and is used by surgeons as a coating for wounds; but its chief application is as a vehicle for the sensitive film in photography.

WordNet 3.0

1. n. a colorless syrupy solution of pyroxylin in ether and alcohol; used as a coating for wounds or photographic films