Editing Acetylene (section)

===Niche applications===
In 1881, the Russian chemist Mikhail Kucherov<ref>{{Cite journal|doi=10.1002/cber.188101401320|title=Ueber eine neue Methode direkter Addition von Wasser (Hydratation) an die Kohlenwasserstoffe der Acetylenreihe|year=1881|last1=Kutscheroff|first1=M.|journal=Berichte der Deutschen Chemischen Gesellschaft|volume=14|pages=1540–1542|url=https://zenodo.org/record/1425226|access-date=9 September 2019|archive-date=2 December 2020|archive-url=https://web.archive.org/web/20201202225306/https://zenodo.org/record/1425226|url-status=live}}</ref> described the [[Hydration reaction|hydration]] of acetylene to [[acetaldehyde]] using catalysts such as [[mercury(II) bromide]]. Before the advent of the [[Wacker process]], this reaction was conducted on an industrial scale.<ref>{{cite journal | title = Hydration of Acetylene: A 125th Anniversary | author1 = Dmitry A. Ponomarev | author2 = Sergey M. Shevchenko | journal = [[J. Chem. Educ.]] | volume = 84 | issue = 10 | year = 2007 | page = 1725 | url = http://jchemed.chem.wisc.edu/HS/Journal/Issues/2007/OctACS/ACSSub/p1725.pdf | doi = 10.1021/ed084p1725 | bibcode = 2007JChEd..84.1725P | access-date = 18 February 2009 | archive-date = 11 June 2011 | archive-url = https://web.archive.org/web/20110611190527/http://jchemed.chem.wisc.edu/HS/Journal/Issues/2007/OctACS/ACSSub/p1725.pdf | url-status = live }}</ref>

The [[polymerization]] of acetylene with [[Ziegler–Natta catalyst]]s produces [[polyacetylene]] films. Polyacetylene, a chain of CH centres with alternating single and double bonds, was one of the first discovered [[organic semiconductor]]s. Its reaction with [[iodine]] produces a highly electrically conducting material. Although such materials are not useful, these discoveries led to the developments of [[organic semiconductor]]s, as recognized by the [[Nobel Prize in Chemistry]] in 2000 to [[Alan J. Heeger]], [[Alan G MacDiarmid]], and [[Hideki Shirakawa]].<ref name=Ullmann/>

In the 1920s, pure acetylene was experimentally used as an [[inhalation anesthetic]].<ref>{{cite encyclopedia |year=1930 |title=Acetylene in medicine|encyclopedia=[[Encyclopaedia Britannica]] |edition=14|volume=1|page=119 |author=William Stanley Sykes |author-link=William Stanley Sykes |language=en}}</ref>

Acetylene is sometimes used for [[carburization]] (that is, hardening) of steel when the object is too large to fit into a furnace.<ref name=BOC2006>{{cite web |url=http://boc.com/products_and_services/by_product/acetylene/index.asp |title=Acetylene |publisher=BOC |website=Products and Services |archive-url=https://web.archive.org/web/20060517074022/http://boc.com/products_and_services/by_product/acetylene/index.asp |archive-date=2006-05-17 }}</ref>

Acetylene is used to volatilize carbon in [[radiocarbon dating]]. The carbonaceous material in an archeological sample is treated with [[lithium]] metal in a small specialized research furnace to form [[lithium carbide]] (also known as lithium acetylide). The carbide can then be reacted with water, as usual, to form acetylene gas to feed into a [[mass spectrometer]] to measure the isotopic ratio of carbon-14 to carbon-12.<ref>{{cite journal|last=Geyh, Mebus|title=Radiocarbon dating problems using acetylene as counting gas|journal=Radiocarbon|year=1990|volume=32|issue=3|pages=321–324|doi=10.2458/azu_js_rc.32.1278|url=https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/1278/1283|access-date=2013-12-26|archive-date=26 December 2013|archive-url=https://web.archive.org/web/20131226194553/https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/1278/1283|url-status=live|doi-access=free}}</ref>

Acetylene combustion produces a strong, bright light and the ubiquity of [[Carbide lamp|carbide lamps]] drove much acetylene commercialization in the early 20th century. Common applications included coastal [[Lighthouse|lighthouses]],<ref>{{Cite web|title=Lighthouse Lamps Through Time by Thomas Tag {{!}} US Lighthouse Society|url=http://uslhs.org/lighthouse-lamps-through-time|access-date=2017-02-24|website=uslhs.org|language=en|archive-date=25 February 2017|archive-url=https://web.archive.org/web/20170225130406/http://uslhs.org/lighthouse-lamps-through-time|url-status=live}}</ref> [[Street light|street lights]],
<ref name="Myers">{{Cite book|last=Myers|first=Richard L.|url=https://books.google.com/books?id=0AnJU-hralEC|title=The 100 Most Important Chemical Compounds: A Reference Guide|date=2007|publisher=ABC-CLIO|isbn=978-0-313-33758-1|language=en|pages=7-9|access-date=21 November 2015|archive-date=17 June 2016|archive-url=https://web.archive.org/web/20160617093705/https://books.google.com/books?id=0AnJU-hralEC|url-status=live}}</ref> and [[Headlamp|automobile]]<ref>Grainger, D., (2001). By cars' early light: A short history of the headlamp: 1900s lights bore port and starboard red and green lenses. National Post. [Toronto Edition] DT7.</ref> and [[Miner's helmet|mining]] [[Headlamp (outdoor)|headlamps]].<ref name="Thorpe-2005">{{cite book|last=Thorpe|first=Dave|title=Carbide Light: The Last Flame in American Mines|publisher=Bergamot Publishing|year=2005|isbn=978-0976090526}}</ref> In most of these applications, direct combustion is a [[fire hazard]], and so acetylene has been replaced, first by [[Incandescent light bulb|incandescent lighting]] and many years later by low-power/high-lumen LEDs. Nevertheless, acetylene lamps remain in limited use in remote or otherwise inaccessible areas and in countries with a weak or unreliable central [[Electrical grid|electric grid]].<ref name="Thorpe-2005"/>