88 Beginnings of Porcelain 



was burned. In thin fragments the material is somewhat translucent. 

 A somewhat thick micro-section transmits light as freely as do many 

 rock-sections, although confusion from the overlapping of much fine 

 detail does not permit a very profitable study of the section. 



It is not possible to tell from the examination of any well-burned 

 vitrified ware whether the mixture from which it is burned is of natural 

 or artificial origin. It would not be at all impossible, although per- 

 haps a task of some difficulty, to find along the outcrop of some peg- 

 matite dike kaolin-like material from which a body identical with this 

 might be burned. The Japanese, formerly at any rate, burned their 

 wares from a single clay, while the Chinese use a mixture. This ware 

 might have been prepared either way. 



The raw material contained iron-bearing minerals in coarse grains 

 only. Each grain has left its individual splash of glassy black slag. 

 The absence of any marked tone of buff, green, or yellow in the color of 

 the mass indicates that there was no important quantity of finely-divided 

 ferruginous mineral present. A simple and crude washing would have 

 eliminated the iron-bearing minerals. Although the pottery does not 

 look at all like porcelain, the only real point of difference, as far as 

 the body is concerned, is the porosity of the ware. This porosity seems 

 to be due to the use of too coarsely ground material, with not enough 

 fine to fill the interspaces. It is a porcelain froth. 



The Outside Red Glaze. — The red glaze on the outside is very 

 thin. Its surface is rough and interrupted by numerous minute black 

 blotches, where ferruginous minerals from the body have penetrated. 

 The glaze is very uniformly distributed. It has not run during firing, 

 nor has it crazed since. It is in as good condition to-day, as on the 

 day it was made. It has, as well as may be determined under a power- 

 ful magnifying-glass, the structure, or rather lack of structure, of a 

 uniform, translucent, vitrified mass. It seems to be a simple slip 

 of some good red-burning clay. It is so thin that a sample for analysis 

 could not be obtained. Between the red coating and the body is a 

 white engobe coat. This nowhere exceeds one-tenth of a millimetre 

 in thickness. It differs from the similar coating under the transparent 

 glaze of the inside of the vessel only in its greater thinness and in the 

 possession of a slight pinkish color, apparently absorbed from the 

 overlying glaze. In places this coat becomes very thin and even 

 occasionally disappears. 



The Inside Glaze. — That surface of the fragment examined, 

 which corresponds to the inside of the vessel of which it formed a part, 

 is covered with a transparent glaze upon a porcelain-like engobe. 

 This engobe coat is thicker than that upon the outside of the vessel. 



