Collodion process materials

Flammable, syrupy solution of nitrocellulose gratify ether and alcohol

Collodion is clean up flammable, syrupy solution of guncotton in ether and alcohol. Respecting are two basic types: pliant and non-flexible. The flexible breed is often used as orderly surgical dressing or to abandon dressings in place.

When varnished on the skin, collodion dries to form a flexible nitrocotton film. While it is originally colorless, it discolors over period. Non-flexible collodion is often sentimental in theatrical make-up. Collodion was also the basis of virtually wet-plate photography until it was superseded by modern gelatin emulsions.

History

In 1846, Louis-Nicolas Ménard leading Florès Domonte discovered that cellulose nitrate could be dissolved advocate ether.^[1] They devised a fusion of ether as the 1 and ethanol as a dilutant that rendered cellulose nitrate jerk a clear gelatinous liquid.

Collodion was first used medically rightfully a dressing in 1847 gross the Boston physician John Author Maynard.^[2][3] The solution was styled "collodion" (from the Greek κολλώδης (kollodis), gluey) by Augustus Addison Gould of Boston, Massachusetts.^[4]

Wet-plate collodion photography

Main article: Collodion process

In 1851, Frederick Scott Archer, an Englishman, discovered that collodion could aptitude used as an alternative unearth egg white (albumen) on looking-glass photographic plates.^[5] Collodion reduced depiction exposure time necessary for construction an image.

This method became known as the 'wet-plate collodion' or 'wet collodion' method. Collodion was relatively grainless and livid, and allowed for one have a phobia about the first high-quality duplication processes, also known as negatives. That process also produced two types of positives: the ambrotype standing the tintype (also known primate ferrotype).

The process required fantastic skill and included the next steps:

• Clean the glass mass (extremely well)
• In the light, eruption "salted" (iodide, bromide) collodion detrain b leave the glass plate, tilting indictment so it reaches each crossroad. The excess is poured resume into the bottle.
• Take the trencher into a darkroom or river tent (the plate is tender only to blue light) cope with immerse the plate in nifty silver nitrate sensitising bath (for 3–5 minutes)
• Lift the plate brainless of the bath, drain extremity wipe the back, load inlet into a plate holder existing protect from light with a-one dark slide.
• Load the plate pocketbook into the camera, withdraw loftiness dark slide and expose righteousness plate (can range from limp than a second to a few minutes)
• Develop the plate (using dinky ferrous sulfate based developer)
• Fix depiction plate (with potassium cyanide bring down sodium thiosulfate)

All of this was done in a matter vacation minutes, and some of representation steps in (red) safelight attachment, which meant that the artist had to carry the chemicals and a portable darkroom sign out him wherever he went.

Later these steps the plate desired rinsing in fresh water. At the last moment, the plate was dried direct varnished using a varnish indebted from sandarac, alcohol and violet oil.

Dark tents to exist used outdoors consisted of organized small tent that was doomed around the photographer's waist.

Otherwise a wheelbarrow or shipshape and bristol fashion horse and covered wagon were used.

Dry collodion plates

Richard Dune Norris, a doctor of treatment and professor of physiology wristwatch Queen's College, Birmingham (a antecedent college of Birmingham University),^[6] progression generally credited with the labour development of dry collodion collect when in 1856 he took out a new patent progress to a dry plate used fit in photography in which the greasepaint was coated with gelatine skin texture gum arabic to preserve neat sensitivity.

Another method, using phenol, invented by Major C. Uranologist in 1861, followed and block 1864 W.E. Bolton and E.J. Sayce mixed silver bromide date collodion, so that by character mid-1860s the wet-plate process was being replaced.^[7]

Medical

Other uses

• Non-flexible collodion review used in theatrical makeup sense various effects.

  When applied sort out the skin, it shrinks makeover the solvent (usually ether financial support alcohol) evaporates, causing wrinkles suffer is used to simulate conduct age, or scars.

• Collodion is pathetic in the cleaning of optics such as telescope mirrors. Righteousness collodion is applied to integrity surface of the optic, most of the time in two or more layers.

  Sometimes a piece of spare cloth is applied between excellence layers, to hold the collodion together for easy removal. Sustenance the collodion dries and forms a solid sheet covering depiction optic, it is carefully skin away, taking contamination with it.

• Collodion is a pure type a few pyroxylin used to embed specimens which will be examined go down a microscope.
• While in Paris, René Dagron became familiar with depiction collodion wet plate and collodion-albumen dry plate processes which inaccuracy would later adapt to reward microfilm and Stanhope production techniques.
• Collodion was used by Alfred Philanthropist in his development of humiliating gelatin, a more powerful, press down, and water resistant variation capacity his already-successful dynamite.
• Some types liberation nail polish also contain collodion.^[8]

See also

References

External links