292 PROCEEDINGS OF THE ACADEMY OP [1880. 



All Enclosure in Quartz. — Mr. H. C. Lewis exhibited a crystal of 

 quartz from Herkimer County, N. Y., in wliich, hanging from a 

 bubble which moved in a cavity containing liquid, was a tuft of 

 minute acicular crystals of a pure white color. A microscopical 

 examination had failed to identify them with any known substance. 

 The crystals were similar to those of many organic salts. It was 

 conjectured that they had crystallized out from the liquid. Under 

 a power of 75 they looked like tufts of white wool, and it was 

 suggested that if future investigation failed to refer them to a 

 known mineral species, it might be convenient to give them the 

 name Erilite (from £V>:ov, wool). 



In other cavities in the same crystal thei-e was an amorphous 

 yellow^ish-brown w^axy substance of unknown composition. 



Menaccanite and Talc from Maryland — Mr. Wm. W. Jefferis 

 remarked that in Harford Count}^, Md., near the village of Dublin, 

 there is a vein of green foliated Talc in the serpentine, which has 

 been opened about 6 feet in length. It has furnished cleavage 

 foliated specimens over a foot in extent. The same vein contains 

 Menaccanite in tabular crystals, Avell crystallized. Yellow beryl 

 has also been found there, showing all three in the same specimen. 



Sunstone in Lahradorite. — Mr. Jefferis stated that on examin- 

 ing a specimen of Labradorite in his possession, from the coast of 

 Labrador, he found that in addition to the usual play of colors 

 (blue and green), by turning it in another direction it showed 

 innumerable crystals of giithite, making it a beautiful sunstone, 

 which, he believed, was an unusual thing, and w4iich he had not 

 found mentioned in the books. 



On a Probable Pseudomorphism of Gummite and Uranotile after 

 Uraninile. — Dr. A. E. Foote remarked that among a number of 

 specimens of gummite and uranotile, that he had recently' received 

 from Mitchell Co., N. C, he noticed some which were of remark- 

 ably regular form. The edges were slightl}' rounded, but they 

 were apparently simple prisms belonging to the triclinic system. 

 On breaking these open he found a solid core of uraninite, sur- 

 rounded by a layer of gummite, and this, in turn, surrounded b^^ 

 a layer of uranotile. Although crystals of uraninite have never 

 been obsei-ved, he ventured to suggest that this is plainly a case 

 of pseudomorphism after uraninite. He hoped hereafter to obtain 

 crystals wdiose angles can be accurately measured. 



He had observed nt least twenty specimens having evidentl}- the 

 same crystalline form, and all plainly pseudomorphs after some 

 pre-existing crystal. The majority of those that were broken open 

 showed the alteration of uraninite into gummite, and of gummite 

 into uranotile ; though in a few the uraninite had been changed, 

 and the crystal showed simply gummite and uranotile. 



