Fluor Spar of Genesee and Illinois. 367 
suppose. Every one prepares for it, and no one ventures 
out without being properly guarded. On that orang 
cold day, Jan. 25th, wrapped in buffaloe skins, &e. I 
drove six miles ina sleigh without any inconvenience, 
11. Crystals of Snow. seul 
Professor Dewey, in a letter to the editor, mentions, 
tions, that in a late fall of snow, he observed dotible crystals, 
formed by a junction of two of the stars of six rays and of 
two others of the same form, but with bifurcated points ; 
they, were, in each instance, united” ne ends of the three 
contiguous rays, on each crystal, ‘akkoF:- eyed the middle 
ray of the three, formed, in each instance, a right 
line passing through both crystals. The single-crystal we 
suppose to be correctly represented in Figs. 1 and 4 of 
that plate of Vol. IL. which illustrates Professor —— 
cn on snow crystals,—see page 338. 
12. Fluor Spar of Genesee. 
_We have Boe received _(May 1, 1821) rekon Mr. H. R. 
2% i Mays” deo ? 
ie a SS Le 
ed oes = ee a et from Rochester on pepe 
er in the bed of the great canal. They are scattered in cav- 
ities of secondary lime-stone rocks. The discoverer re- 
marks that this mineral is found there in considerable quan- 
tities, and that some, crystals are an inch and a half square. 
_N. B. We presume that if this locality be not eractly the 
same as that mentioned page 235 of this volume, it must at 
least be in the same formation; the specimens | 
from Mr. Boyd and from Mr. Fenn; cannot be di: 
bern each other. —Ep. 
3. Fluor ‘Spor of Hlinois. 
ee pete Vol. L. we mentioned this locality of aoe 
, and again at page 243 o: present 
same this day (May 2, 1821) reeeived through the kindness of 
Capt. Abm. Hawkins of Sh pinata pie 
mens, which we mention for for the sake of drawing the atten- 
tion of mineralogists to this locality, the most remarkable 
