™ 
omic Volume of some Minerals. 227 
A1=6418-+3:07 (@ gr.=161- 1 “ 161-7-4-5==32°3 
m. #e==1000+5'212 (sp. gr.)=192 C. 192+5=—38-4 
As, 940°08-+-5°75 (sp. gr.}=163, which equals 5X 826, The spe- 
38 gives for atomic volume 160. 
1 Si 57731 0. atoms of acid and base, 4. ¢. atoms of elements, 10. 
3 Be 474-25 A. 105156-+-2°97 (sp. gr.)—=354 
a. At. weight, 105156 B. 854-+-4—885 ©. 354-+10—=85-4 
With te old atomic weight for glucinum, Phenacite has the formula Be Si2, 
which giv 
A. ai: ge 97 (sp. gr.)=713 C. 7138-+13==55, which is 1} times that 
of specular ir 
Antimony, pain Tellurium and Osmium are isomorphous with Arsenic. 
. Antimony, Sb, 1612-8-+6°702 (sp. gr.)}=240°65 
6. Bismuth, Bi, 1330:4-+-9°8 (sp. gr.)—=135°75 
7. Tellurium, Te, 802--+6-2 (sp. gr.)—=129°36 
8. Osmium, Os, 1242°6-+10 (sp. gr.}=124-26 
The atomic volume of Corundum is to that of Arsenic as 1:5, to that of Antimony 
nearly as 1:8, and to that of each of the other metals following nearly as 1:4. The 
discrepancies, if ene te such, it will be observed are among acknowledged iso- 
morphs; and a more exact knowledge of the atomic weight may remove them. 
nae eremeye Tungstate of Lead, Fergusonite. 
i, 
1 W 1488-4 6, atoms of acid and base, 2, c¢, atoms of elements, 6. 
10a 3515 A. 1889-9-+6'1 (sp. gr.)==801 
a. At. weight, 18399 B. 301-6-+-2—150°8 ©. 801:6+6=50°3 
2. Tungstate of Lead. 
1 W —1488-4 A. 2889:9--8'1 (sp. ees 
1Pb 13945 B, 355°9-+2—177-9 355-946-593 
a, At, weight, 2882-9 
8. Fergusonite. b. atoms of acid and base, 7. —_¢. atoms of elements, 7. 
1 fa . 25968 A. 5611:8+-5'8 (sp. gr.)-—=9675 
6 Y 30150 B, 967:5-+-7—=1382 C. 967° 5117570. 
3 a. At. weight, 56118 
We have introduced here the acknowledged isomorph of Scheelite, Tungstate of 
Lead, in order to afford a more satisfactory comparison with Fergusonite. 
r V. Zircon, Rutile, Tin Ore (acknowledged isomorph of rutile). 
1. Zircon. 
1 Sim 577-31 3. atoms of acid and base, 2. ¢. atoms of "a 9. 
1 Zr 1139-50 A. 17168144636 ae gr.)=370 
a, At. weight, 171681 B. 3703-+2—185-15 ©. 870°3-+9—_41°15, 
* tile, Pi—514-7-+-4-21 (ap. gr.) — 1223. —«O.:122.3-+ 840-7 
8. Tin Ore. §n—935:3-+-6:96 (sp. gr) 1844. 0. «1344+ 3-—44'8 
