The main application of<unk> c chloride is as a catalyst for the conversion of acetylene to vinyl chloride, the precursor to polyvinylchloride: :C2H2 + HCl → CH2=CHCl For this application, the<unk> c chloride is supported on carbon in concentrations of about 5 weight percent. This technology has been eclipsed by the thermal cracking of 1,2-dichloroethane. Other significant applications of<unk> c chloride include its use as a depolarizer in batteries and as a reagent in organic synthesis and analytical chemistry (see below). It is being used in plant tissue culture for surface sterilisation of explants such as leaf or stem nodes. As a chemical reagent<unk> c chloride is occasionally used to form an amalgam with metals, such as aluminium. Upon treatment with an aqueous solution of<unk> c chloride, aluminium strips quickly become covered by a thin layer of the amalgam. Normally, aluminium is protected by a thin layer of oxide, thus making it inert. Once amalgamated, aluminium can undergo a variety of reactions. For example, upon removal of the oxide layer, the exposed aluminium will immediately react with water generating Al(OH)3 and hydrogen gas. Halocarbons react with amalgamated aluminium in the Barbier reaction. These alkylaluminium compounds are nucleophilic and can be used in a similar fashion to the Grignard reagent. Amalgamated aluminium is also used as a reducing agent in organic synthesis. Zinc is also commonly amalgamated using<unk> c chloride.<unk> c chloride is used to remove dithiane groups attached to a carbonyl in an umpolung reaction. This reaction exploits the high affinity of<unk> 2+ for anionic sulfur ligands.<unk> c chloride may be used as a stabilising agent for chemicals and analytical samples. Care must be taken to ensure that detected<unk> c chloride does not eclipse the signals of other components in the sample, such as is possible in gas chromatography. Historical use in photography<unk> (II) chloride was used as a photographic intensifier to produce positive pictures in the collodion process of the 1800s. When applied to a negative, the<unk> (II) chloride whitens and thickens the image, thereby increasing the opacity of the shadows and creating the illusion of a positive image. Historical use in preservation For the preservation of anthropological and biological specimens during the late 19th and early 20th centuries, objects were dipped in or were painted with a "mercuric solution". This was done to prevent the specimens' destruction by moths, mites and mold. Objects in drawers were protected by scattering crystalline<unk> c chloride over them. It finds minor use in tanning, and wood was preserved by kyanizing (soaking in<unk> c chloride).<unk> c chloride was one of the three chemicals used for railroad tie wood treatment between 1830 and 1856 in Europe and the United States. Limited railroad ties were treated in the United States until there were concerns over lumber shortages in the 1890s. The process was generally abandoned because<unk> c chloride was water-soluble and not effective for the long term, as well as being highly poisonous. Furthermore, alternative treatment processes, such as copper sulfate, zinc chloride, and ultimately creosote; were found to be less toxic. Limited kyanizing was used for some railroad ties in the 1890s and early 1900s. Historic use in medicine<unk> c chloride was a common over-the-counter disinfectant in the early twentieth century, recommended for everything from fighting measles germs to protecting fur coats and exterminating red ants. A New York doctor, Carlin Philips, wrote in 1913 that “it is one of our most popular and effective household antiseptics,” but so corrosive and poisonous that it should only be available by prescription. A group of doctors in Chicago made the same demand later the same month. The product frequently caused accidental poisonings and was used as a suicide method. It was used to disinfect wounds by Arab physicians in the Middle Ages. It continued to be used by Arab doctors into the twentieth century, until modern medicine deemed it unsafe for use. Syphilis was frequently treated with<unk> c chloride before the advent of antibiotics. It was inhaled, ingested, injected, and applied topically. Both<unk> c-chloride treatment for syphilis and poisoning during the course of treatment were so common that the latter's symptoms were often confused with those of syphilis. This use of "salts of white<unk> " is referred to in the English-language folk song "The Unfortunate Rake". Yaws was treated with<unk> c chloride (labeled as Corrosive Sublimate) before the advent of antibiotics. It was applied topically to alleviate ulcerative symptoms. Evidence of this is found in Jack London's book The Cruise of the Snark in the chapter entitled "The Amateur M.D." Historic use in crime and accidental poisonings *In volume V of Alexandre Dumas' Celebrated Crimes, he recounts the history of Antoine François Desrues, who killed a noblewoman, Madame de Lamotte, with "corrosive sublimate". *In 1906, in New York, Richard Tilghman died after mistaking bichloride of<unk>  tablets for lithium citrate tablets. *In one highly publicized case in 1920,<unk>  bichloride" was reported to have caused the death of 25-year-old American silent-film star Olive Thomas. While vacationing in France and staying at the Hôtel Ritz in Paris, she accidentally (or perhaps intentionally) ingested the compound, which had been prescribed to her husband Jack Pickford in liquid topical form to treat his "chronic syphilis". Thomas died five days later. *Mercuric chloride was used by Madge Oberholtzer to commit suicide after she was kidnapped, raped, and tortured by Ku Klux Klan leader D.C. Stephenson. Oberholtzer died from a combination of<unk>  poisoning and staph infection, the latter caused by Stephenson biting her during the assault. *Ana María Cires, a young wife of Uruguayan writer Horacio Quiroga, committed suicide by poisoning herself. After a violent fight with the writer, she ingested a fatal dose of "sublimado", or<unk> (II) chloride. She endured terrible agony for eight days before dying on December 14, 1915.
Mercury
Ethylmercury
Dimethylmercury
Metaldehyde
Vinyl chloride
Lead
Arsenic
Lindane