Gold parting in 1860's Australia. It is able to refine gold up to 99.5% purity. The process involves blowing a stream of chlorine gas over and through a crucible filled with molten impure gold. Impurities in the gold form chlorides before the gold does and these insoluble salts are removed from the melt by skimming the surface. Invented by Emil Wohlwill in 1874, this produces the highest purity gold (99.999%). It is an electrolytic process using pure gold for the cathode (or titanium as a starter cathode) and chloroauric acid (gold chloride-hydrochloric acid) as the electrolyte; this is made by dissolving gold
Purity and Danger Purity and Danger Purity and Danger: An Analysis of Concepts of Pollution and Taboo is a 1966 book by the anthropologist and cultural theorist Mary Douglas. It is her best known work. In 1991 the "Times Literary Supplement" listed it as one of the hundred most influential non-fiction books published since 1945. It has gone through numerous reprints and re-editions (1969, 1970, 1978, 1984, 1991, 2002). In 2003 a further edition was brought out as volume 2 in "Mary Douglas: Collected Works" (). The line of inquiry in "Purity and Danger" traces the words and meaning of dirt in different