Editing Collodion

{{Short description|Flammable, syrupy solution of nitrocellulose in ether and alcohol}}
[[File:Alfred Stieglitz by Frank S. Herrmann.jpg|thumb|Alfred Stieglitz, {{circa|1894}}, collodion print by Frank S. Herrmann]]
'''Collodion''' is a flammable, syrupy solution of [[nitrocellulose]] in [[Diethyl ether|ether]] and [[Alcohol (chemistry)|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 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 Collodion was also the basis of most [[Collodion process|wet-plate photography]] until it was superseded by modern gelatin emulsions.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 [[diethyl ether|ether]].<ref>Initially, the French referred to cellulose nitrate as ''xyloïdine'' and ''pyroxyline'':
*  Pelouze announced to the French Academy of Sciences that Ménard and Domonte had discovered that cellulose nitrate could be dissolved in ether in:  Pelouze (9 November 1846) [http://gallica.bnf.fr/ark:/12148/bpt6k2980r/f865.image.langEN "Observations sur la xyloïdine,"] ''Comptes rendus'' … , '''23''' : 861–862.
*  Ménard and Florès Domonte (1846) [http://gallica.bnf.fr/ark:/12148/bpt6k2980r/f1091.image.langEN "Sur la pyroxyline"] (On pyroxyline), ''Comptes rendus'' … , '''23''' : 1187–1188.</ref> They devised a mixture of ether as the solvent and [[ethanol]] 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]] physician John Parker Maynard.<ref>John Parker Maynard (1848) [https://books.google.com/books?id=tNI9AQAAMAAJ&pg=RA1-PA178 "Discovery and application of the new liquid adhesive plaster,"] ''The Boston Medical and Surgical Journal'', '''38''' : 178–183.</ref><ref>This claim was contested by the Swiss chemist [[Christian Friedrich Schönbein]], one of several investigators who had independently discovered [[nitrocellulose]].  See:  C. F. Schoenbein (1849) [https://books.google.com/books?id=ORZAAAAAcAAJ&pg=PA289 "On ether glue or liquor constringens; and its uses in surgery,"] ''The Lancet'', '''1''' :  289–290.</ref> The solution was dubbed "collodion" (from the Greek κολλώδης (''kollodis''), gluey) by [[Augustus Addison Gould]] of Boston, Massachusetts.<ref>{{Cite journal |last=Maynard |first=John P. |year=1867 |title=Collodion |url=https://books.google.com/books?id=uVcsAAAAYAAJ&pg=RA1-PA36 |journal=The Boston Medical and Surgical Journal |volume=75 |pages=36–39}}</ref>

==Wet-plate collodion photography==
{{Main|Collodion process}}<!-- Linked from elsewhere! -->[[Image:1860 Anonyme Un vétéran et sa femme Ambrotype.jpg|right|thumb|Anonymous "A Veteran with his Wife", ambrotype]]
[[Image:Alice Liddell as Pomona by Julia Margaret Cameron.jpg|right|thumb|[[Julia Margaret Cameron]]'s "[[Alice Liddell]] as a Young Woman" print from wet collodion negative]]

In 1851, [[Frederick Scott Archer]], an Englishman, discovered that collodion could be used as an alternative to [[egg white]] (albumen) on glass photographic plates.<ref>Frederick Scott Archer (March 1851) [https://books.google.com/books?id=VxoFAAAAQAAJ&pg=PA257 "On the use of collodion in photography,"] ''The Chemist'' … , new series, '''2''' (19) :  257–258.</ref> 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 [[Negative (photography)|negatives]]. This process also produced two types of [[Positive (photography)|positives]]: the [[ambrotype]] and the [[tintype]] (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]], [[bromide]]) 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]] light) and immerse the plate in a [[silver nitrate]] 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 (photography)|dark slide]].
* Load the plate holder into the camera, withdraw the [[Dark slide (photography)|dark slide]] and expose the plate (can range from less than a second to several minutes)
* Develop the plate (using a [[ferrous sulfate]] based [[photographic developer|developer]])
* Fix the plate (with [[potassium cyanide]] or [[sodium thiosulfate]])

All of this was done in a matter of minutes, and some of the steps in (red) [[safelight]] 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]] made from [[sandarac]], [[ethanol|alcohol]] and [[lavender oil]].

Dark tents to be used outdoors consisted of a small tent that was tied around the photographer's waist. Otherwise a [[wheelbarrow]] 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]]),<ref>{{cite web | url=http://archiveshub.ac.uk/data/gb150-us41 | title=University of Birmingham Staff Papers: Papers of Dr Richard Hill Norris - Archives Hub}}</ref> 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]] in which the emulsion was coated with [[gelatine]] or [[gum arabic]] 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]] with collodion, so that by the mid-1860s the wet-plate process was being replaced.<ref>Hannavy, John (ed.) (2008) Encyclopedia of nineteenth-century photography: A–I, Volume 1, Taylor & Francis, p. 440</ref>

==Medical==
* Many wart-remover preparations consist of [[acetic acid]] and [[salicylic acid]] in an [[acetone]] collodion base used in the [[treatment of warts by keratolysis]].
* [[Nitrocellulose]] (pyroxylin) solution is also used in [[liquid bandage]] products. <!-- How is it used medically if it is toxic as mentioned above? -->
* 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]] 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 [[optical|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.
* Collodion is a pure type of pyroxylin used to embed specimens which will be examined under a [[microscope]].
* While in Paris, [[René Dagron]] became familiar with the collodion wet plate and collodion-albumen [[dry plate]] processes which he would later adapt to his [[microfilm]] and [[Stanhope (optical bijou)|Stanhope]] production techniques.
* Collodion was used by [[Alfred Nobel]] 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.<ref>Cosmetic Ingredient Review (2013), [http://www.cir-safety.org/sites/default/files/nitroc062013FR.pdf "Safety Assessment of Nitrocellulose and Collodion as Used in Cosmetics"]</ref>

==See also==
* [[Collodion baby]]
* [[Collodion process]]

==References==
{{reflist}}

==External links==
[[File:Rev David Leavitt.jpg|thumb|right|250px|Rev. David Leavitt, {{abbr|ca.|circa}}&nbsp;1855, wet collodion negative, [[Library of Congress]]]]
* [https://web.archive.org/web/20130521234312/http://blog.eastmanhouse.org/2012/06/13/photographic-process-2-0-the-collodion-process/ WATCH: George Eastman House "The Collodion – Photographic Processes"]
* [http://www.getty.edu/art/gettyguide/videoDetails?cat=2&segid=1726 The Getty Museum: The Wet Collodion Process] {{Webarchive|url=https://web.archive.org/web/20141019053829/http://www.getty.edu/art/gettyguide/videoDetails?cat=2&segid=1726 |date=2014-10-19 }}
* [https://www.pbs.org/wgbh/amex/eastman/sfeature/wetplate_step1.html Step by Step Wet Plate Photography]
* [http://www.npg.si.edu/exh/brady/animate/photitle.html Making a Photograph During the Brady Era]
* [http://johncoffer.com John Coffer]
* [http://collodion.com Collodion]
* [https://web.archive.org/web/20181114104409/http://hazard.com/msds/mf/baker/baker/files/c5060.htm Collodion: Material Safety Data Sheet]
* [http://home.intekom.com/pharm/sad-otc/comp-w.html Compound W data sheet] {{Webarchive|url=https://web.archive.org/web/20190528024936/http://home.intekom.com/pharm/sad-otc/comp-w.html |date=2019-05-28 }}
* [https://web.archive.org/web/20090213212928/http://www.cwreenactors.com/phorum/list.php?1 Civil War Reenactors Photography Forum]
* [http://unblinkingeye.com/Articles/WPC/wpc.html Getting started in Wet Plate Collodion Photography]
* [https://web.archive.org/web/20130521234312/http://blog.eastmanhouse.org/2012/06/13/photographic-process-2-0-the-collodion-process/ Origins and the process of creating a collodion print]

[[Category:Nitrate esters]]
[[Category:Photographic chemicals]]
[[Category:Cellulose]]