ELISHA MITCHELL SCIENTIFIC SOCIETY. 5 



other minerals, transported from the debris of the crys- 

 talline rocks occurring along- the borders of the Pied- 

 mont plateau, not man}^ miles away. 



The points above noted ma\^ explain, perhaps, the 

 confusion which has arisen in the use of the term "ka- 

 olin." The applicability of this name to the material 

 described above as having- its orig-in directly in the 

 larg-e g-ranitic dikes, I suppose no one will question. 

 But if the residual material of dike-decomposition has 

 been transported a short distance by the streams and 

 deposited without further sorting- the materials, or if 

 it has been transported to a much g-reater distance, so 

 that the sorting- has become fairly complete, and the 

 mineral kaolinite, while separated from the quartz and 

 mica of the original mass remains unmixed with other 

 foreig-u materials, so as to be itself fairly pure, — the 

 question arises whether the term kaolin is still appli- 

 cable in both cases; and if so, to what extent, in its 

 transportation and sorting-, this material may become 

 mixed w^ith other foreig-n materials resulting- from the 

 decay of crystalline rocks in the reg-ion throug-h which 

 it has been transported, before the term kaolin svould 

 become inapplicable. In other words, where, in such 

 a case, should we discontinue the use of the word "ka- 

 olin" and apply the broader term "clay"? Further 

 discussion of this question cannot be attempted in this 

 paper; but it is mentioned here because the writer has 

 recently heard a number of complaints from practical 

 potters who use the clay-material on a commercial 

 scale, that many people throug-hout the countr\^ were 

 designating- all the samples of their material forward- 

 ed as "kaolin," regardless of their color and other 

 characteristics. 



Through many places, both in the mountain- and the 



