ALUMINA. 297 



6. SCOLEZITE. 



This mineral was analyzed with great care by 

 Gehlen and Fuchs, who, from a mean of many 

 trials, state its constituents as follows : 



Silica . . 46-4 



Alumina . 25-7 



Lime . 14'2 



Water . . . . 13-6 



100-0 



I have analyzed various specimens of scolezite ; 

 but only one of them was quite free from soda, 

 and its constituents were almost exactly the same 

 as those found by Gehlen and Fuchs. In the 

 other specimens the quantity of soda varied from 

 0%5 to 1*5 per cent. $ showing that the mineral 

 contained a mixture of natrolite. 



Let us suppose that scolezite is a compound of 

 3 integrant particles of silicate of alumina and 1 

 integrant particle of trisilicate of lime, with 3 

 atoms of water, and let us see what its constitu- 

 ents will be on that supposition. 



2'25 : 2 : : 25-7 : 22-844 = silica united to alumina. 

 3-5:6: : 14-2 : 24-3428 = silica united to lime. 



Now, 22-844 + 24-3428 = 47-1868, which sur- 

 passes the silica actually found in scolezite by 

 0-6868. 



The silica united to the lime is of the 



