PORCELAIN STONE, POTTERS CLAY, KAOLIN, SLATE. 313 



is only indicated by cubic cavities containing sulphur." ^ The 

 bleached Liparite of the Lipari Islands, and the grey-white 

 Rhyolithe of Hungary are perhaps the results of similar changes 

 under the influence of solfataras, at least they resemble strongly 

 the Arita and Amakusa rock, concerning the chemical composition 

 and employment of which more will be said in the section on 

 Ceramics. 



2. Disintegration. Products of common felspar and kindred 

 minerals and rock rich in argillaceous earth. Kaolin belongs to this 

 class, and the plastic clays in their varied modifications, even to 

 common loam. 



The principal sources of porcelain stone and Kaolin, the basic 

 material of fine pottery, are indicated in the tables with the pro- 

 ducts of mining industry proper, and will be further treated under 

 Ceramics. 



Porcelain stone and Kaolin, are taken from the surface of the 

 ground, and do not therefore belong properly to mining, but to 

 the Gioku-seki-rui, the family of stones which are obtained from 

 the quarry, Jap. Ishi-yama (stone mountain), or Ishi wo hori-dasu 

 tokoro {i.e., place where stone is dug out). It has been shown in 

 the first volume of this work, that freestone proper, and stone in 

 general, has had but very subordinate use in building, e.g., for the 

 massive walls of old fortresses, stairs leading to temples located on 

 heights, stone turrets, monuments, bridges, pavements of temple 

 courts and gardens, cooking hearths, wash-basins and rice troughs. 

 For these purposes they used almost without exception granite, 

 especially the Mikage-ishi from Settsu, and the Teshima-ishi from 

 Bizen, besides trachytic and doleritic lava, as well as the older slate. 

 Common limestone is burned and its powder (Ishi-bai, i.e., stone 

 powder) is used as a manure, but seldom for building purposes. 

 Marble, called R6-seki and Sarusa-ishi by the Japanese, is found 

 in several parts of the country, in Bizen, Mino, and Hitachi. 

 Some statues in and around temples, from the white marble 

 of Hitachi — quarried near the coast north of Mito, the capital — 

 show that it is spendidly qualified for the purposes of sculpture. 

 From the variegated marble (Fusuline lime) of Akasaka in Mino, 

 a variety of small articles are cut, among them saucers to rub 

 India-ink in. 



Slabs of old slate, Seki-ban, or Date-ishi, are used for paving 

 walls in gardens and courts, and large ones for small bridges over 

 streams and irrigating ditches. 



The greyish blue slate which resembles our slate used for pencils 

 in hardness, colour, and grain, is employed very extensively in 

 the manufacture of India-ink saucers. The best known and most 

 celebrated for this purpose is the Amabata-ishi from the province of 

 Kai, whose quarrying and working, owing to the large demand, has 



^ Pumpelly : "Across America and Asia," p. 177. 



