soda were determined according to the customary methods. 
Pro itney,* in his analyses of the sodalite and its 
Silica, . - i » - 87°33 
Alumina, - - “ = 3 82-70 
Oxyd of iron, - : - - trace. 
Soda, -: - - “ - 94°31 
‘Chlorine, - : ¢ ‘ 2 6°99 
101°33 
But on the other hand, assigning to the percentage of chlorine 
enough of sodium to form chlorid of sodium in accordance with 
von Kobell’s formula of this mineral (Na*Si+3&ISi+NaCl), we have 
18-17 for the percentage of soda in combination with silica. 
Hence the analysis will stand thus: 
ilica, . - 87:33 
apa : “ ° * - 82°10 
da, - ‘ - - - 18°17 
Sodium, - “ - - - > AST 
Shiesine, 7 : a : : — ; Nacl 
formula, . 
Elwolite-—The eleolite from Salem possesses all the constant 
hysical properties of this variety of nepheline. Its color is 
dull green, its lustre greasy, and its fracture sub-conchoidal. It 
'S sub-translucent, and in structure massive. Its specific gravity 
is 2629. Its chemical composition I find to be as follows: 
99°76 
These results are sufficiently in agreement with the established 
ula 
i. 
- - 44:31 4407 
—/ = a - 82°80 
eroxyd of iron, - - trace 
Lime, : - “40 
; - - - 1643 
Potash, - 3 +50 oo 
Ignition, - a - - 147 
100°91 
Schenectady, N. Y., September, 1859. 
* Poggendorff’s Annalen, lxx, 433. 
