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KAOLIN

Volume 6 · 165 words · 1778 Edition

the name of an earth which is used as one of the two ingredients in oriental porcelain. Some of this earth was brought from China, and examined by Mr Reaumur. He found that it was perfectly fusible by fire, and believed that it was a talc earth; but Mr Macquer observes, that it is more probably of an argillaceous nature, from its forming a tenacious paste with the other ingredient called petunse, which has no tenacity. Mr Bomare says, that by analysing some Chinese kaolin, he found it was a compound earth consisting of clay, to which it owed its tenacity; of calcareous earth, which gave it a mealy appearance; of sparkling crystals of mica; and of small gravel, or particles of quartz crystals. He says, that he has found a similar earth upon a stratum of granite, and conjectures that it may be a decomposed granite. This conjecture is the more probable, as kaolins are frequently found in the neighbourhood of granites. See Porcelain.