288 EARTHS PROPER. 



1. NEPHELINE. 



It was stated in p. 177 of this work, that from 

 the late analysis of nepheline, by Arfwedson, its 



constituents are as follows : 







Silica . 44-11 



Alumina . 33-73 



Soda . 20-46 



Water . 0-62 



98-92 



It was shown that nepheline is a compound of 

 3 integrant particles of silicate of alumina, and 1 

 integrant particle of sesquisilicate of soda. It 

 was shown that the portion of silica united to 

 the alumina was 29*17 grains. Now, 



29-17 (the quantity of silica) : 33-?3 (the alumina) : : 2 



Gives (atom of silica) : 2-3126 = atom of alumina. 



2-3126. 



2. KARPHOLITE. 



Karphoiite This rare mineral occurs in the Schlacken- 

 wald in Bohemia, and was named by Werner, 

 from the resemblance of its colour to straw. It 

 occurs in very fine needles, which usually diverge 

 from a point. Its specific gravity is 2'923 ; it 

 seems to be rather soft. Strom eyer,* from a 

 very careful analysis of this mineral, has given 

 its constituents as follows : 



* Untersuchungen, I. p. 410. 



