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|Section2= |Section3= }} White lead is the basic lead carbonate (2PbCO3·Pb(OH)2).〔''Inorganic Chemistry'',Egon Wiberg, Arnold Frederick Holleman Elsevier 2001 ISBN 0-12-352651-5〕 It is a complex salt, containing both carbonate and hydroxide ions. White lead occurs naturally as a mineral, in which context it is known as hydrocerussite,〔 a hydrate of cerussite.〔''see'' mineral hydration〕 It was formerly used as an ingredient for lead paint and a cosmetic called Venetian Ceruse, because of its opacity and the satiny smooth mixture it made with dryable oils. However, it tended to cause lead poisoning, and its use has been banned in most countries.〔(Hernberg, S. Lead Poisoning in a Historical Perspective ), American Journal of Industrial Medicine 38:244-254 (2000)〕 White lead compounds were also used as lubricants for bearings and in machine shops, especially between work being turned in a lathe and a dead center. ==History== The commonly known Dutch method for the preparation of lead white was described as early as Theophrastus of Eresos〔J. R. Partington, ''A Short History of Chemistry'' (1937)〕 (ca. 300 B.C.), in his brief work on rocks or minerals, ''On Stones'' or ''History of Stones.'' His directions for the process were repeated throughout history by many authors of chemical and alchemical literature. The uses of cerussa were described as an external medication and as a pigment. Clifford Dyer Holley quotes from Theophrastus' ''History of Stones''〔Theophrastus, ''History of Stones'', p.223〕 as follows, in his book (''The Lead and Zinc Pigments'' ).
Later descriptions of the Dutch process involved casting metallic lead as thin buckles and corroded with acetic acid in the presence of carbon dioxide. This was done by placing them over pots with a little vinegar (which contains acetic acid). These were stacked up and covered with a mixture of decaying dung and spent tanner's bark, which supplied the CO2, and left for six to fourteen weeks, by which time the blue-grey lead had corroded to white lead. The pots were then taken to a separating table where scraping and pounding removed the white lead from the buckles. The powder was then dried and packed for shipment or shipped as a paste.〔(Lead411.org ) based on Warren, Christian. 'Toxic Purity: The progressive era origins of America’s lead paint poisoning epidemic'. ''Business History Review''. Winter 1999, Vol. 73(4)〕 One benefit of the process was that it was not necessary to dry the paste of white lead, removing its water. All that needed was to mill the paste with linseed oil, and the white lead would take up the oil and reject the residual water, to give white lead in oil. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「White lead」の詳細全文を読む スポンサード リンク
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