KAOLIN IN" WISCOXSIK". 



11 



various stages of decomposition. The kaolinite portion is removed 

 from the weathered rock by allowing streams of water to run over 

 it. The clay thus washed out settles in a series of large catch-pools. 

 The weathered rock itself is used to a considerable extent in the 

 ceramic arts in England, under the name of Cornish stone. 



At Aue in Saxony the source of the kaolin was a rounded mass 

 of granite ver}'" much decomposed on the surface and surrounded 

 by the kaolin as by a cap.* The deposit is exhausted. At Mionia 

 in Saxony, the kaolin is decomposed porphyr}-, and is used in the 

 Dresden manufactories.f At the Einigheit mine near Freiberg, 

 Saxony, it is in nests in gneiss. J The kaolin of La Bresse, France, 

 is an altered andesite.|| That of Bayonne, France, is a graphic 

 granite in every stage of decomposition.^ At Passau the occur- 

 rence is exactly like that of St. Yrieix in France.§ 



The following are analyses of crude European kaolins:** 



A few occurrences of kaolinized rock are known in the United 

 States, of such a nature as to supply a good article. An excellent 

 material is found in the graphic granite of Brunswick, Maine, and 

 also at Haddam, Connecticut. At each place the rock is a coarse 

 mixture of very pure quartz and felspar. At the latter locality it 

 has been of late mined and broken up for making kaolin for white 

 ware at Williamsburg, N. Y.ft Near Trenton in New Jersey the 

 gneissic rocks are more felspathic than usual in the region, and the 

 felspar is entirely changed to kaolin, which is dug to be used in 

 making fire-brick.JJ This clay contains zireonia. 



Kaolin as a hedded clay. — As a bedded clay kaolin is knovai in 



* Knapp, vol. II, p. 230. ^ Knapp, Loc. cit. 



t Wagner Chem. Technol, p. 230. ^ Dana's Mineralog}-, p. 348. 



i Percy's Metallurgy, Vol. on Fuels, p. 96. '^ - Wagner, Loc. cit. 

 I'lUre's Dictionary, Vol. 1, p. 427. ff Appleton's Encyclopedia, Art. Clay. 



XX Geology of New Jersey, -p. 323. 



