Collodion
Appearance
Collodion is a solution of nitrocellulose in ether or acetone, sometimes with the addition of alcohols. Its generic name is pyroxylin solution. It is toxic and highly flammable. As the solvent evaporates, it dries to a celluloid-like film.
- Celloidin is a pure type of pyroxylin used to embed specimens which will be examined under a microscope. [1]
- It was used as a wound dressing, as an emulsion in some early photographic plates (the collodion process), and various other topical medications. One example, Compound W Wart Remover, still exists, consisting of acetic acid and salicylic acid in an acetone collodion base.
- Collodion was widely used to glue electrodes to the head for electroencephalography until the 1990s. It has been replaced by water-based gels in most uses to avoid the contact with acetone, which is not only contained in the glue but needed in quantity for electrode removal.
- Pyroxylin with added pigments is used as a nitrocellulose lacquer.
- It was also added to nitroglycerine to stabilise it as blasting gelatine.
- Collodion is also used in theatrical makeup for various effects, such as simulating old-age wrinkles or scars.
- Collodion also finds use in the cleaning of optics such as telescope mirrors. The collodion is applied to the surface of the optic, usually in two or more layers. Sometimes a piece of thin cloth is applied between the layers, to hold the collodion together for easy removal. After the collodion dries and forms a solid sheet covering the optic, it is carefully peeled away taking contamination with it.
Reference
External links
- Scully & Osterman Studio
- George Berkhofer Collodion Artist
- Contemporary Wet Plate Images (Quinn Jacobson/Studio Q)
- Wet Plate Forum Board
- Wet Plate Chemistry Kits
- Alt Photo Publisher
- Modern Day Collodion Photographer - William Dunniway
- Contemporary 19th Century Wetplate Collodion Photography
- Collodion: Material Safety Data Sheet
- Compound W data sheet
- Modern images of the ambrotype process