26 NEW YORK STATE MUSEUM 



sand. This sand layer causes considerable trouble, for without the 

 exercise of much care it gets into the clay, and such mixed clay 

 is unsuitable for slip. Above this sand layer comes the uppermost 

 productive layer of slip, a 4 foot bed of very regular composition 

 and which is in greater demand for electric insulator purposes than 

 the next lower bed. 



Onondaga county makes the only other production of crude clay. 

 This material consists of a brown banded tough clay used chiefly 

 in the manufacture of red ware. 



FELDSPAR 



No new quarries of feldspar were developed or worked in 191 5, 

 but there was an unusual manifestation of interest in the local 

 feldspar resources by reason of the possibilities they offer for the 

 production of potash. 



It is well known that the extraction of potash from silicate 

 minerals offers no special difficulties, so far as laboratory operations 

 are concerned; fusion with some strong base like lime is all that 

 is needed to release the alkalies from combination with the silica 

 and bring them into soluble form. Though the feasibility of apply- 

 ing this process on a commercial scale has been discussed for a 

 long time, no definite steps have been taken toward putting it in 

 practice, and the matter still is in an experimental stage. The 

 recent interest is the result of the curtailment of potash shipments, 

 since practically all the supply of this very essential material is 

 imported from Germany, which in normal times affords most of 

 the requirements of the whole world. 



The utilization of feldspar for the purpose has been investigated 

 recently by Cushman and Hall J whose work has been given wide 

 currency and has been the means of attracting much atention gen- 

 erally to the subject. Their method is based on the use of calcium 

 chloride as flux. The feldspar is first pulverized and agglomerated 

 with a little lime and then brought to fusion in a furnace with the 

 aid of calcium chloride. By this treatment the alkalies are con- 

 verted into chlorides which can then be leached from the fused 

 mass with hot water. The solution will contain both potassium 

 and sodium chlorides, the relative amounts varying of course with 

 the proportions represented in the feldspar. 



1 American Inst. Chem. Engineers, Philadelphia meeting, December 1914. 

 The article is published in full in Metallurgical and Chemical Engineering, 

 13 : 2, February 1915. 



