654 Generai Notes. [June, 
minerals is rendered much more exact. He treats with especial 
detail the cryolite group of minerals. Cvyolile is shown to be 
monoclinic instead of triclinic. Pachnolite and thomsenolite are 
shown to be species distinct from each other, the latter mineral 
containing one molecule of water, as already proved by Brandl? 
The crystals of pachnolite are monoclinic, having generally the 
form of slender prisms, the prisms being striated horizontally. 
Thomsenolite has the same characters, both minerals decrepitating 
strongly when heated. Ralstonite, an isometric mineral, and 
chiolite, a tetragonal mineral resembling cryolite, have been re 
examined and Brandl gives. them new formule. Arksutite is 
shown to be merely a mixture of cryolite and pachnolite, and not 
a distinct species. 
A Norwecian Dust SHower.--On the 26th of last February 
a fine dust was discovered overlying the snow in Trondhjem Amt 
(district of Drontheim), in Norway, and like the dust showers 
which followed the volcanic outbreak of 1876, was thought to 
indicate a recent volcanic eruption in Iceland. Dr. Reuse of 
the mineralogical faculty of the University of Christiania, has, 
however, shown that it is not of eruptive origin, but const 
common sand, fine particles of quartz, hornblende and talc on 
some associated fine particles of vegetable matter. — Althou . 
volcanic origin of this dust has been disproved, it 1s neverth 
of interest, considering the wide extent of snow-covered country 
over which this dust was deposited. 
Microuite From Expa.—A. Corsi? has found small crystals of : 
microlite at several localities in Elba. It occurs in granitic f° ae l 
and is associated with albite, orthoclase, tourmaline, lepidolite, ¢te 
The principal forms are octahedra and rhombic dodecahedra. y 
color it varies at different localities from dark, dirty geen 
low, and from being opaque to transiucent, the eae i 
being reddish-yellow. The powder is grayish-white. 49%; 
characters are those usual to microlite. oo 
F. Fontaine 
Ametia County, Va., Minerats.—Professor W. f Amelia 
contributes an interesting article upon the minerals ne d The 
o., Va., giving much information not heretofore publishe helvite, 
microlite and monazite, columbite, fluorite, beryl, ort mae elvite, 
etc., are each described in detail. In the description mits t0 
which includes Mr. Sloan’s analysis, Professor Fonta a ‘al by 
make any mention of the original discovery of that = 
Professor Lewis l ee A 
Tne Wm. S. Vaux CorLecrion.—This magnificent = certain 
minerals and archæological specimens, bequeathed un 
1 AMER. NATURALIST for Jan., 1883, p. 76. 
*Boll. R. Com. Geologico, 1881. 564. 
"Am. Four. Se. and Arts, May, 1883. 
