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Collodion

Collodion

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Collodion is a flammable, syrupy solution of pyroxylin
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...

 (a.k.a. "nitrocellulose", "cellulose nitrate", "flash paper", and "gun cotton") in ether and alcohol. There are two basic types; flexible and non-flexible. The flexible type is often used as a surgical dressing or to hold dressings in place. When painted on the skin, collodion dries to form a flexible cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

 film. While it is initially colorless, it discolors over time. Non-flexible collodion is often used in theatrical make-up.

Wet plate collodion photography




In 1851, the Englishman Frederick Scott Archer
Frederick Scott Archer
Frederick Scott Archer invented the photographic collodion process which preceded the modern gelatin emulsion. He was born in Bishop's Stortford in the UK and is remembered mainly for this single achievement which greatly increased the accessibility of photography for the general public.tyler was...

 discovered that collodion could be used as an alternative to egg white
Egg white
Egg white is the common name for the clear liquid contained within an egg. In chickens it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms around either fertilized or unfertilized egg yolks...

 (albumen) on glass plates. This also reduced the exposure time when making the image. This became known as the 'wet plate collodion' or 'wet collodion' method. Collodion was also grainless and colorless, and allowed for one of the first high quality duplication processes, also known as negatives
Negative (photography)
In photography, a negative may refer to three different things, although they are all related.-A negative:Film for 35 mm cameras comes in long narrow strips of chemical-coated plastic or cellulose acetate. As each image is captured by the camera onto the film strip, the film strip advances so that...

. This process also produced positives, the ambrotype
Ambrotype
right|thumb|Many ambrotypes were made by unknown photographers, such as this American example of a small girl holding a flower, circa 1860. Because of their fragility ambrotypes were held in folding cases much like those used for [[daguerreotype]]s...

 and the tintype
Tintype
Tintype, also melainotype and ferrotype, is a photograph made by creating a direct positive on a sheet of iron metal that is blackened by painting, lacquering or enamelling and is used as a support for a collodion photographic emulsion....

 (also known as 'ferrotype').

The process required great skill and included the following steps:
  • Clean the glass plate (extremely well)
  • In the light, pour "salted" (iodide
    Iodide
    An iodide ion is the ion I−. Compounds with iodine in formal oxidation state −1 are called iodides. This page is for the iodide ion and its salts. For information on organoiodides, see organohalides. In everyday life, iodide is most commonly encountered as a component of iodized salt,...

    /bromide
    Bromide
    A bromide is a chemical compound containing bromide ion, that is bromine atom with effective charge of −1. The class name can include ionic compounds such as caesium bromide or covalent compounds such as sulfur dibromide.-Natural occurrence:...

    ) collodion onto the glass plate, tilting it so it reaches each corner. The excess is poured back into the bottle.
  • Take the plate into a darkroom
    Darkroom
    A darkroom is a room that can be made completely dark to allow the processing of light sensitive photographic materials, including photographic film and photographic paper. Darkrooms have been created and used since the inception of photography in the early 19th century...

     or orange tent (the plate is only sensitive to blue
    Blue
    Blue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 440–490 nm. It is considered one of the additive primary colours. On the HSV Colour Wheel, the complement of blue is yellow; that is, a colour corresponding to an equal...

     light) and immerse the plate in a silver nitrate
    Silver nitrate
    Silver nitrate is an inorganic compound with chemical formula . This compound is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides...

     sensitising bath (for 3–5 minutes)
  • Lift the plate out of the bath, drain and wipe the back and load it into a dark slide
    Dark slide (photography)
    In photography, a dark slide is a wooden or metal plate that covers the sensitized emulsion side of a photographic plate. In use, a pair of plates joined back to back were used with both plates covered with a dark slide...

     (UK terminology) or plate holder (US terminology)
  • Load the plate holder into the camera, withdraw the dark slide and expose the plate (can range from less than a second to several minutes)
  • Develop the plate (using a ferrous sulfate based developer
    Photographic developer
    In the processing of photographic films, plates or papers, the photographic developer is a chemical that makes the latent image on the film or print visible. It does this by reducing the silver halides that have been exposed to light to elemental silver in the gelatine matrix...

    )
  • Fix the plate (with potassium cyanide
    Potassium cyanide
    Potassium cyanide is an inorganic compound with the formula KCN. This colorless crystalline compound, similar in appearance to sugar, is highly soluble in water. Most KCN is used in gold mining, organic synthesis, and electroplating. Smaller applications include jewelry for chemical gilding and...

     or sodium thiosulfate
    Sodium thiosulfate
    Sodium thiosulfate , also spelled sodium thiosulphate, is a colorless crystalline compound that is more familiar as the pentahydrate, Na2S2O3•5H2O, an efflorescent, monoclinic crystalline substance also called sodium hyposulfite or “hypo.”...

    )


All of this was done in a matter of minutes, and some of the steps in (red) safelight
Safelight
A safelight is a light source suitable for use in a photographic darkroom. It provides illumination only from parts of the visible spectrum to which the photographic material in use is nearly or completely insensitive.- Design :...

 conditions, which meant that the photographer had to carry the chemicals and a portable darkroom with him wherever he went. After these steps the plate needed rinsing in fresh water. Finally, the plate was dried and varnished using a varnish
Varnish
Varnish is a transparent, hard, protective finish or film primarily used in wood finishing but also for other materials. Varnish is traditionally a combination of a drying oil, a resin, and a thinner or solvent. Varnish finishes are usually glossy but may be designed to produce satin or semi-gloss...

 made from sandarac
Sandarac
Sandarac is a resin obtained from the small cypress-like tree Tetraclinis articulata. The tree is native to the northwest of Africa with a notable presence in the Southern Morocco part of the Atlas mountains. The resin exudes naturally on the stems of the tree. It is also gotten by making cuts on...

, alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

 and lavender oil
Lavender oil
Lavender oil is an essential oil obtained by distillation from the flower spikes of certain species of lavender. Two forms are distinguished, lavender flower oil, a colorless oil, insoluble in water, having a density of 0.885 g/mL; and lavender spike oil, a distillate from the herb Lavandula...

.

Dark tents to be used outdoors consisted of a small tent that was tied around the photographer's waist. Otherwise a wheelbarrow
Wheelbarrow
A wheelbarrow is a small hand-propelled vehicle, usually with just one wheel, designed to be pushed and guided by a single person using two handles to the rear, or by a sail to push the ancient wheelbarrow by wind. The term "wheelbarrow" is made of two words: "wheel" and "barrow." "Barrow" is a...

 or a horse and covered wagon were used.

Dry collodion plates


Richard Norris, a doctor of medicine and professor of physiology at Queen's College, Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...

, is generally credited with the first development of dry collodion plate in the 1860s. In 1894 he took out a new patent for dry plate
Dry plate
Dry plate, also known as gelatin process, is an improved type of photographic plate. It was invented by Dr. Richard L. Maddox in 1871, and by 1879 it was so well introduced that the first dry plate factory had been established...

 used in photography
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...

.

Medical

  • 'Compound W Wart Remover' consists of acetic acid
    Acetic acid
    Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...

     and salicylic acid
    Salicylic acid
    Salicylic acid is a monohydroxybenzoic acid, a type of phenolic acid and a beta hydroxy acid. This colorless crystalline organic acid is widely used in organic synthesis and functions as a plant hormone. It is derived from the metabolism of salicin...

     in an acetone
    Acetone
    Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

     collodion base used in the treatment of warts by keratolysis.
  • Nitrocellulose
    Nitrocellulose
    Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...

     (pyroxylin) solution is also used presently in 'MedTech's NewSkin' liquid bandage
    Liquid bandage
    Liquid bandage is a topical skin treatment for minor cuts and sores that is sold by several companies. The products are mixtures of chemicals which create a polymeric layer which binds to the skin...

     product.

Other uses

  • Collodion is widely used to glue electrodes to the head for electroencephalography
    Electroencephalography
    Electroencephalography is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain...

    .
  • Non-flexible collodion is used in theatrical makeup for various effects, such as simulating old-age wrinkles or scars. When applied to the skin, it shrinks as the solvent (usually ether or alcohol) evaporates, causing wrinkles and is used to simulate old age, or scars.
  • Collodion is used in the cleaning of optics such as telescope
    Telescope
    A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

     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.
  • Collodion is a pure type of pyroxylin used to embed specimens which will be examined under a microscope
    Microscope
    A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...

    .
  • While in Paris René Dagron
    René Dagron
    René Prudent Patrice Dagron was a French photographer and inventor. He was born in Aillières-Beauvoir, Sarthe, France....

     became familiar with the collodion wet plate and collodion-albumen dry plate
    Dry plate
    Dry plate, also known as gelatin process, is an improved type of photographic plate. It was invented by Dr. Richard L. Maddox in 1871, and by 1879 it was so well introduced that the first dry plate factory had been established...

     processes which he would later adapt to his microfilm and Stanhope
    Stanhope (optical bijou)
    Stanhopes or Stanho-scopes are optical devices that enable the viewing of microphotographs without using a microscope. They were invented by René Dagron in 1857. Dagron bypassed the need for an expensive microscope to view the microscopic photographs by attaching the microphotograph at the end of a...

     production techniques.
  • Collodion was used by Alfred Nobel
    Alfred Nobel
    Alfred Bernhard Nobel was a Swedish chemist, engineer, innovator, and armaments manufacturer. He is the inventor of dynamite. Nobel also owned Bofors, which he had redirected from its previous role as primarily an iron and steel producer to a major manufacturer of cannon and other armaments...

     in his development of blasting gelatin, a more powerful, flexible, and water resistant variation on his highly successful product, Dynamite
    Dynamite
    Dynamite is an explosive material based on nitroglycerin, initially using diatomaceous earth , or another absorbent substance such as powdered shells, clay, sawdust, or wood pulp. Dynamites using organic materials such as sawdust are less stable and such use has been generally discontinued...

    .
  • Some types of nail polish
    Nail polish
    Nail polish, or nail varnish, is a lacquer applied to human fingernails or toenails to decorate and/or protect the nail plate.-History:...

    also contain collodion.

External links