86 
Journal of the Mitchell Society 
[ November 
smooth, white, porcelain or chalky appearance, but after having 
been in use about 500 hours, it is rough or crystalline in appear- 
ance. 
The yttria contents used in the manufacture of the Nernst glow- 
er are obtained principally from the mineral gadolinite, which has 
not thus far been found in North Carolina. There are, however, 
a number of minerals containing yttria, such as samarskite, eux- 
enite and fergusonite, which have been found in the State. 
The magnetite and ilmenite may find a use in the manufacture 
of magnetite electrodes that are manufactured by the General 
Electric Company. 
The garnet grains are sharp and can be used for abrasive pur- 
poses in the manufacture of garnet paper, which is used extensive- 
ly in the boot and shoe trade. 
