176 Josiah Wedgwood CHAP. 



Lord Camelford joined him in the manufacture of 

 china. It appears from a letter from that nobleman to 

 Polwhele, the historian of Cornwall, that the two ex- 

 pended about 3000 in prosecuting the work. 



It may be mentioned that the Cornish clay resembles 

 the Chinese kaolin. It is locally known as Growan. It 

 is found in the granite of several districts ; sometimes 

 it contains talc in place of mica, and is characterised 

 by the partial decomposition of the felspar. The China 

 clay or porcelain earth requires- to be carefully and 

 constantly washed with running water, until it is 

 perfectly white. It is afterwards consolidated, dried, 

 and cut into oblong blocks, when it is sent to the 

 nearest port and shipped to the potteries, there to be 

 manufactured into china and the finer kinds of earthen- 

 ware. 



The materials from the kaolin of St. Stephens, said 

 Cookworthy when speaking of his manufacture, " burn 

 to a degree of transparency without the addition of 

 Petunse. 1 Indeed, the materials from this place make 

 a body much whiter than the ascatea, and, I think, full 

 as white as the ancient china ware or that of Dresden." 

 Cookworthy established himself as a china manufacturer 

 at Plymouth, where the buildings, called "China House," 

 are still to be seen. 



Cookworthy, being an experienced chemist, paid 

 much attention to the production of a good blue. He 



1 The fine clay used by the Chinese with the kaolin, in their manu- 

 facture of porcelain. 



