Fluor Spar of Genesee and Elinois. 367 



suppose. Every one prepares for it, and no one ventures 

 out without being properly guarded. On tliat extremely 

 cold day, Jan. 25th, wrapped in bufFaloe skins, furs, &.c. J 

 drove six miles in a sleigh without any inconvenience. 



1 1 . Crystals of Snow. 



Professor Dewey, in a letter to the editor, mentions, 

 tions, that in a late fall of snow, he observed double 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 by the ends of the three 

 contiguous rays, on each crystal, and of course, the middle 

 ray of the three, formed, in each instance, a continued right 

 line passing through both crystals. The single crystals we 

 suppose to be correctly represented in Figs. 1 and 4 of 

 that plate of Vol. II. which illustrates Professor Green's 

 piece on snow crystals, — see page 338. 



12. Fluor Spar of Genesee. 



We have just received (May 1, 1821) from Mr. H. R. 

 Fenn, of Rochesterville, Ontario County, N. Y. some spe- 

 cimens of well crystalized fluor spar, which were discover- 

 ed by him, half a mile from Rochester on the Genesee riv- 

 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 tliere 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 exactly the 

 same as that mentioned page 235 of this volume, it must at 

 least be in the same formation; the specimens received 

 from Mr. Boyd and from Mr. Fenn, cannot be distinguished 

 from each other, — Ed. 



13. Fluor Spar of Illinois. 



At page 52 "Vol. I. we mentioned this locality of fluor 

 spar, and again at page 243 of the present volume. We 

 have this day (May 2, 1821) received through the kindness of 

 Capt. Abm. Hawkins of Shawneetown, some superb speci- 

 mens, which we mention for the sake of drawing the atten- 

 tion of mineralogists to this locality, the most remarkable 



