270 Scientific Intelligence. 
n(OzM2), may thus be homologous. ‘The above formulas are intended 
to involve no hypothesis as to the arrangement of the elements, for in 
the author’s view, each species is an individual, in which the different 
species that may be obtained by its decomposition, have no actual 
existence. 
He regards those silicates which like eudialyte, sodalite, and pytos- 
2)n 
malite, contain metallic chlorids, as oxychlorids, —(M2O2)n. MCI, and 
nosean, haiiyne and lapis-lazuli as basic sulphates = (M202) 20s, 
while cancrinite, and perhaps some scapolites, are basic carbonates. 
All other silicates are reducible to the same t s the spinels, 
of 7:14+8:0=15'1. Boracic, 
tanic, niobic and tantalic acids are Te 
duced to the same formula as ‘ 
ti 
silica 
so that 
16 and 9 
The triclinic feldspars, of which albite and anorthite may be taken 
as the representatives, furnish another example; the one !s 4 lime 
feldspar, Gat Si+ 34158i, and the other a soda feldspar, Na Si+ MIS 
multiplying the first by $, and the second by 4, and expanding, they 
are reduced to a common formula Me4Oca. Petalite, a lithia feldspar, 
also enters into the same formula, with a similar equivalen 
while orthoclase belongs to a homologous genus, w ich is Me 
The formulas with their equivalent weights, densities, and volumes; a" 
as follows: oi 
Eq. wt. Dens. 405-0 
Anorthite . . (SisealesCas)Oca = 11184 + 2°76 = # 4 
Albite . . . (Siseal:aNas)Oea = 1054-4 > 2°62 = 402 
Petalite . . . (Sis1alioLis)Oca 
Orthoclase . . (Siasali2K3)Oco 
Ul Ul 
13-80 = 100-00, which agrees with a large number of UN?” 
although there are varieties which appear to contain more al “ ite, 
Between anorthite and albite, may be placed vosgite, lab sue 
andesine, and oligoclase, whose composition and densities nd bave 
that they all enter into the same general formula with them, @ 
the same equivalent volume. The results of their analysis a msy 
means constant, and it is probable that many, if not all of them, 
