Atomic. Volume of some.Minerats. 233 
serh cine relation, exhibiting, satisfactorily the intimate relations of f the or 
: ry £} 4 oe gi I +5 1 58 85, 
1921+13—= =147-4, 1017+7=14 
4. We eins, Weiaii, from Rothlaue analyzed by Rammelsberg, 
(Pegs, leviii, 509 
Si a 73193 6. atoms of acid and bases, 8. ¢. atoms of cc 28. 
13 Al 1069-7 A. 4189°43+-3°387 ( gr.) =12 
+¥Pe 33333 B, 1237+8=1546 1237> anu 
8 Oa 105447 
a. At. weight, 4189: 
Here 44:2 is but little sil the determination for Bpidota, 
XVII. The Feldspar Family.—In Orthoclase and Albite, Pe and Labrador- 
ite, Loxoclase and Oligoclase, we have three examples of dimorphis 
i 1, Orthoclase, R Si+A1 Sis —Form monoclinic. 
Si 2309-24 6. atoms of acid and bases, 6. c¢. atoms of elements, 23. 
1 Al 641-80 A. 3539°90—-2:55 (sp. gr.) =1388 
1K 58886 B. 1388—6—2313 C. 1888 —238==60'4 
a. At. weight, 3539-90 
2. Albite, R RSi+AI 8 Si3.—Form triclinic. 
==2309-24 6. atoms of acid and bases, 6. ¢. atoms i! — 238. 
1 Al 641-80 A. 3341-94+2°61 (sp. gr.) =12 
1Na 3909 B. 1280-4+6=2184 ©. 1280: pi 67 
a, At. weight, 3341-94 
8. Ryacolite, R Si+A1 Si—Monoclinic. 
2 Si ==1154-62 5. atoms of acid and base es, 4. ¢. atoms of el ts, 15. 
1 Al 641:80 A. 223683+-2°58 (as fr): =s0t 
3 Na 2932 B, 86742167 er 
4K 147-21 
a. At. weight, 223683 
4. Labradorite, RBiTAIS Si. _tviclinie. 
=1154'62 &. atoms of acid and bases,4. c¢. atoms a 15. 
1 Al 641-80 A. 2147 Tr (sp. gr.) =795 
1 Ga $5149 B, 795 pngritcde C. 795° plese pt 
a, At. weight, "214791 
5. Loxoclase, R Si +41 Si2—Monoclinic. 
3 Si =1731-93 6. atoms of acid and bases, 5. ¢ atoms of ore 
141 = 641-80 A. 2779°52+2°615 (sp. &) =106 
§Na 24431 B. 1068-+-5=212°6 ‘dasnades 
}K 
4 Ca 87-87 
a. At. weight, 2779: 
6. Oligoclase, R Si--a1 8 Si2 —Triclinie. 
3 Si 1731-93 4%. atoms of acid and bases, 5. «. ssn of elements, 19, 
14l C¢641-80 A. 275149265 (sp. gr.) =10883 
@Na 2606 8B. 1038'3-+-5==207°66 ©. 1038°3-+19==54647 
$Ca =: 11716 
a. At. weight, "2751-49 51-4 im 
Szconp § oe 1850. 
‘. ERtEs, Vol. re. No, 26.—March, 
