Tetrachloroethylene, also known under its systematic name tetrachloroethene and many other names, is a chlorocarbon with the formula Cl2C=CCl2. It is a colourless liquid widely used for dry cleaning
Dry cleaning
Dry cleaning is any cleaning process for clothing and textiles using a chemical solvent other than water. The solvent used is typically tetrachloroethylene , abbreviated "perc" in the industry and "dry-cleaning fluid" by the public...

 of fabrics, hence it is sometimes called "dry-cleaning fluid." It has a sweet odor detectable by most people at a concentration of 1 part per million (1 ppm). Worldwide production was about 1 megatonne in 1985.
Michael Faraday
Michael Faraday
Michael Faraday, FRS was an English chemist and physicist who contributed to the fields of electromagnetism and electrochemistry....

 first synthesized tetrachloroethene in 1821 by thermal decomposition of hexachloroethane
Hexachloroethane, also known as perchloroethanes , C2Cl6, is a colorless solid at room temperature which is used by the US Military in smoke compositions, e.g...

C2Cl6 → C2Cl4 + Cl2

Most tetrachloroethene is produced by high temperature chlorinolysis of light hydrocarbons.