84 F. A. Genth—Amerrcan Vanadium Minerals. 
dium in the roscoelite, a quantity of the mineral was dissolved : 
in dilute sulphuric acid in a sealed tube at a temperature of _ 
about 180° C., and was titered after cooling; the liquid was 
then reduced by hydrosulphuric acid, and after boiling off the _ 
excess of the latter, it was again titered. From the quantity of | 
oxygen required for oxidation in both cases it was found that | 
vanadium in the mineral is present as V,O,, = 2 V,O,, V205- 
The determinations of the other elements were made by the 
usual methods. 
F 
uy a b ca cB a € 1 
Insoluble silicates, 
quartz, gold, &c. == [0°85] _... 11°45 _... 8°91 [5°60] 
iO, = 47°39 47°82 4846 48°60 .... 46°81 
Al,O, ss. 16010, 19805 1067 1296: 1608 
FeO m=. IG2. 820.908 S25... be 
800. (968 9. 15 ee 
CaO0 : == trace trace 0°20 0983 .... trace 
Na,O (trace Li,O) = 0°19 0°38 0.30 84) .. 0°60 
K,O = 759 803 5:35 5-98 ¢ 5:96 8°89 
V¥.0;, == 22°02 21°36 20:50 23°92 .... 20°16 
Ignition = 496 S18 532 595 6°34 3°87 
* 100°22 101°00 100°87 100-00 100°00 
