
Collodion is a flammable, syrupy solution of
nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and ...
in
ether
In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again b ...
and
alcohol
Alcohol most commonly refers to:
* Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom
* Alcohol (drug), an intoxicant found in alcoholic drinks
Alcohol may also refer to:
Chemicals
* Ethanol, one of sev ...
. 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 nitrocellulose film. While it is initially colorless, it discolors over time. Non-flexible collodion is often used in theatrical make-up. Collodion was also the basis of most wet-plate photography until it was superseded by modern gelatin emulsions.
History
In 1846
Louis-Nicolas Ménard and Florès Domonte discovered that
cellulose nitrate could be dissolved in
ether
In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again b ...
. They devised a mixture of ether (ethoxyethane) as the solvent and
ethanol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a h ...
as a diluent that rendered cellulose nitrate into a clear gelatinous liquid. Collodion was first used medically as a dressing in 1847 by the
Boston
Boston (), officially the City of Boston, is the capital city, state capital and List of municipalities in Massachusetts, most populous city of the Commonwealth (U.S. state), Commonwealth of Massachusetts, as well as the cultural and financ ...
physician John Parker Maynard. The solution was dubbed "collodion" (from the Greek κολλώδης (''kollodis''), gluey) by
Dr. A.A. Gould of Boston, Massachusetts.
Wet-plate collodion photography
In 1851,
Frederick Scott Archer
]
Frederick Scott Archer (1813 – 1 May 1857) was an English photographer and sculptor who is best known for having invented the photographic collodion process which preceded the modern gelatin emulsion. He was born in either Bishop's Stortfo ...
, an Englishman, discovered that collodion could be used as an alternative to
egg white
Egg white is the clear liquid (also called the albumen or the glair/glaire) 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 arou ...
(albumen) on glass photographic plates. Collodion reduced the exposure time necessary for making an image. This method became known as the 'wet-plate collodion' or 'wet collodion' method. Collodion was relatively grainless and colorless, and allowed for one of the first high-quality duplication processes, also known as
negatives. This process also produced two types of
positives: the
ambrotype
The ambrotype (from grc, ἀμβροτός — “immortal”, and — “impression”) also known as a collodion positive in the UK, is a positive photograph on glass made by a variant of the wet plate collodion process. Like a pr ...
and the
tintype
A tintype, also known as a melainotype or ferrotype, is a photograph made by creating a direct positive on a thin sheet of metal coated with a dark lacquer or enamel and used as the support for the photographic emulsion. Tintypes enjoyed their w ...
(also known as
ferrotype
A tintype, also known as a melainotype or ferrotype, is a photograph made by creating a direct positive on a thin sheet of metal coated with a dark lacquer or enamel and used as the support for the photographic emulsion. Tintypes enjoyed their w ...
).
The process required great skill and included the following steps:
* Clean the glass plate (extremely well)
* In the light, pour "salted" (
iodide
An iodide ion is the ion I−. Compounds with iodine in formal oxidation state −1 are called iodides. In everyday life, iodide is most commonly encountered as a component of iodized salt, which many governments mandate. Worldwide, iodine def ...
,
bromide
A bromide ion is the negatively charged form (Br−) of the element bromine, a member of the halogens group on the periodic table. Most bromides are colorless. Bromides have many practical roles, being found in anticonvulsants, flame-retardan ...
) 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 or orange tent (the plate is sensitive only to
blue
Blue is one of the three primary colours in the RYB colour model (traditional colour theory), as well as in the RGB (additive) colour model. It lies between violet and cyan on the spectrum of visible light. The eye perceives blue when ...
light) and immerse the plate in a
silver nitrate
Silver nitrate is an inorganic compound with chemical formula . It 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. It was once called ''lunar caustic ...
sensitising bath (for 3–5 minutes)
* Lift the plate out of the bath, drain and wipe the back, load it into a plate holder and protect from light with a
dark slide.
* 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
Iron(II) sulfate ( British English: iron(II) sulphate) or ferrous sulfate denotes a range of salts with the formula Fe SO4·''x''H2O. These compounds exist most commonly as the heptahydrate (''x'' = 7) but several values for x are kn ...
based
developer)
* Fix the plate (with
potassium cyanide
Potassium cyanide is a compound with the formula KCN. This colorless crystalline salt, similar in appearance to sugar, is highly soluble in water. Most KCN is used in gold mining, organic synthesis, and electroplating. Smaller applications i ...
or
sodium thiosulfate
Sodium thiosulfate (sodium thiosulphate) is an inorganic compound with the formula . Typically it is available as the white or colorless pentahydrate, . The solid is an efflorescent (loses water readily) crystalline substance that dissolves well ...
)
All of this was done in a matter of minutes, and some of the steps in (red)
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
A safelight usu ...
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 is a clear transparent hard protective coating or film. It is not a stain. It usually has a yellowish shade from the manufacturing process and materials used, but it may also be pigmented as desired, and is sold commercially in vario ...
made from
sandarac,
alcohol
Alcohol most commonly refers to:
* Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom
* Alcohol (drug), an intoxicant found in alcoholic drinks
Alcohol may also refer to:
Chemicals
* Ethanol, one of sev ...
and
lavender oil
Lavender oil is an essential oil obtained by distillation from the flower spikes of certain species of lavender. There are over 400 types of lavender worldwide with different scents and qualities. Two forms of lavender oil are distinguished, ''l ...
.
Dark tents to be used outdoors consisted of a small tent that was tied around the photographer's waist. Otherwise a
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 at the rear, or by a sail to push the ancient wheelbarrow by wind. The term "wheelbarrow" is mad ...
or a horse and covered wagon were used.
Dry collodion plates
Richard Hill Norris, a doctor of medicine and professor of physiology at
Queen's College, Birmingham (a predecessor college of
Birmingham University
The University of Birmingham (informally Birmingham University) is a Public university, public research university located in Edgbaston, Birmingham, United Kingdom. It received its royal charter in 1900 as a successor to Queen's College, Birmingha ...
), is generally credited with the first development of dry collodion plate when in 1856 he took out a new patent for a
dry plate used in
photography
Photography is the visual art, art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It i ...
in which the emulsion was coated with
gelatine
Gelatin or gelatine (from la, gelatus meaning "stiff" or "frozen") is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also ...
or
gum arabic
Gum arabic, also known as gum sudani, acacia gum, Arabic gum, gum acacia, acacia, Senegal gum, Indian gum, and by other names, is a natural gum originally consisting of the hardened sap of two species of the ''Acacia'' tree, ''Senegalia se ...
to preserve its sensitivity. Another method, using tannin, invented by Major C. Russell in 1861, followed and in 1864 W.E. Bolton and E.J. Sayce mixed
silver bromide
Silver bromide (AgBr) is a soft, pale-yellow, water-insoluble salt well known (along with other silver halides) for its unusual sensitivity to light. This property has allowed silver halides to become the basis of modern photographic materials. Ag ...
with collodion, so that by the mid-1860s the wet-plate process was being replaced.
Medical
* Many wart-remover preparations consist of
acetic acid
Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main componen ...
and
salicylic acid
Salicylic acid is an organic compound with the formula HOC6H4CO2H. A colorless, bitter-tasting solid, it is a precursor to and a metabolite of aspirin (acetylsalicylic acid). It is a plant hormone, and has been listed by the EPA Toxic Substanc ...
in an
acetone
Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour.
Acetone is miscible wi ...
collodion base used in the
treatment of warts by keratolysis.
*
Nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and ...
(pyroxylin) solution is also used in
liquid bandage products.
* EEG electrodes are commonly attached to the patient's scalp with rigid collodion for long-term treatment
Other uses
* Non-flexible collodion is used in theatrical
makeup
The asterisk ( ), from Late Latin , from Ancient Greek , ''asteriskos'', "little star", is a typographical symbol. It is so called because it resembles a conventional image of a heraldic star.
Computer scientists and mathematicians often vo ...
for various effects. 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
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultra ...
such as
telescope
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to obse ...
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
A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...
.
* While in Paris,
René Dagron
René Prudent Patrice Dagron (17 March 1817 – 13 June 1900) 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 processes which he would later adapt to his
microfilm
Microforms are scaled-down reproductions of documents, typically either films or paper, made for the purposes of transmission, storage, reading, and printing. Microform images are commonly reduced to about 4% or of the original document size. F ...
and
Stanhope production techniques.
* Collodion was used by
Alfred Nobel
Alfred Bernhard Nobel ( , ; 21 October 1833 – 10 December 1896) was a Swedish chemist, engineer, inventor, businessman, and philanthropist. He is best known for having bequeathed his fortune to establish the Nobel Prize, though he also ...
in his development of
blasting gelatin, a more powerful, flexible, and water resistant variation of his already-successful
dynamite.
* Some types of
nail polish also contain collodion.
[Cosmetic Ingredient Review (2013)]
"Safety Assessment of Nitrocellulose and Collodion as Used in Cosmetics"
/ref>
See also
* Collodion baby
* Collodion process
The collodion process is an early photographic process. The collodion process, mostly synonymous with the "collodion wet plate process", requires the photographic material to be coated, sensitized, exposed, and developed within the span of abou ...
References
External links
WATCH: George Eastman House "The Collodion – Photographic Processes"
The Getty Museum: The Wet Collodion Process
John Coffer
Collodion
{{Webarchive, url=https://web.archive.org/web/20190528024936/http://home.intekom.com/pharm/sad-otc/comp-w.html , date=2019-05-28
Civil War Reenactors Photography Forum
Origins and the process of creating a collodion print
Nitrate esters
Photographic chemicals
Cellulose