ON THE CHINA-STONE AND CHINA-CLAYS OF CORNWALL. 201 



from whence China-stone is procured presents the appearance of a large 

 rabbit burrow, as there are no less than nine setts for the district, the 

 proprietor of each of which has his portion of the hill covered with the 

 mouths of pits, around which are stationed a number of men with their 

 waggons, who, after the Cliina-stone has been raised by quarrying and 

 the employment of powder, carry it to one of the nearest ports to be 

 shipped for the potteries of Staffordshire and Worcestershire. These 

 ports are distant seven or nine miles from the quarries, entailing in this 

 transport a considerable amount of land carriage, and a consequent in- 

 crease in the price, which of late years has been raised from 12s. to 20s. 

 free on board, at Par, Pentewan, or Charlestown ; still the demand has 

 by no means diminished, and the proprietors of these setts have been 

 obliged to fix a certain limit to their annual supply of 18,000 tons, 

 which rate of consumption will have effected the removal of all the 

 China-stone in these beds in rather less than fifty years. 



The number of people employed in its preparation are comparatively 

 few, as the operation of blasting requires but two or three, persons in 

 each pit ; and in loading the waggons the parties employed as carriers 

 are but too eager to fill in order to gain a load. The before-mentioned 

 reasons render the question of supply an important one, and one well 

 worthy the attention of the landowner as to future resources, and the 

 influence the discovery of any large bed of good stone would exert on 

 his pocket ; though, while the present setts of the China-stone Com- 

 pany of Cornwall hold out, they not only can but will maintain a mono- 

 poly. 



China-stone, in its present state, consists of a mixture of quartz, 

 felspar, and mica, blended so as to form an homogenous mass which 

 very much resemble granite, though its texture is not so compact ; the 

 quartz exists in small bluish-white and transparent crystals, the edges of 

 which, by the process of disintegration, are rendered more or less indis- 

 tinct, and they have become more transparent than when in the form of 

 granite. These crystals are imbedded in a mixture of white felspar which 

 has lost a portion of its potash, and small opaque scales of mica having a 

 lustrous silvery aspect and very thin : the granite from which it has been 

 formed is of the simplest kind, the commoner forms containing, in addition 

 to the mica, quartz and felspar, which may be either red or grey, crystals 

 and scales of horneblende, diallage, or talc, with a more or less appre- 

 ciable amount of iron, indicated by the black spots formed on fusion or 

 calcination ; and as the chemical composition of this article, when pure, 

 should indicate an absence of these deteriorating qualities, until some 

 cheap mode of separating these constituents from the otherwise vitrifi- 

 able granites of Cornwall be found, the China-stone at present in use 

 must retain its pre-eminence, consisting as it does of a pure double 

 silicate of potash and alumina, which, when fused, forms a pearl-white 

 translucent mass, firm and resonant, consisting of an. opaque body of 

 nearly perfectly formed kaolin, surrounded by and diffused through the- 



