Geology and Mineralogy. 153 
boundary of a region of depression is very irregular; moreover 
the continuation of the cross-fracture not unfrequently coincides 
with the longitudinal fractures, and vice versa, (5) The connec- 
tion of the seismical lines of different dynamical value is most 
readily explained by the assumption that a portion of the earth’s 
crust gives its motion to another, and this makes itself felt by the 
shakings along the course of a fracture.—Jahrb. k. k. geol. Keich- 
D 
87, 1878. E. S. D. 
12. Examination of the North Carolina Uranium minerals ; 
by F. A. Gentu (American Chemical Journal, vol. i, p. 87).— 
Professor W. C. Kerr (this Journal, III, xiv, 496, Dec., 1877). As 
stated by him, occur as irregular nodules and rounded 
the minerals to a thorough chemical examination, and in the main 
h : 
surrounding this is an orange-colored mineral, gummite; an 
mineral, identified by Dr. Genth as _uranotil. Che uraninite 
in too small a quantity to allow of its being analyzed 
three analyses gave :— 
UO, AIO, PbO BaO SrO CaO Si0; P,0, H,0 
nian pesseeneic? 
75°20 053 657 1°08 9-05 4°63 0°12 10°54=99°72. 
Dr. Genth regards the gummite as a mechanical mixture of :— 
Uranium hydrate = H.(U02)02 4+H,0 = 4010 p.c 
Uranotil ~ = Cas(UO2)sSieO21 + 18H.O = 33°38 p. c. 
Lead ate = Pb(T02)20s + 6H,O = 22°66 p. ©. 
Barium uranate = Ba(UO,).0;+6H,0 = 4°26 p.c. 
100°40. 
_._The pale yellow coating surrounding the gummite has been 
identified by Dr. Genth as prekolt a mineral originally described 
rolina it is amorphous, compact ; hardness = 2°5; specific 
gravity 3°834; color pale straw-yellow to lemon-yellow ; luster 
waxy to dull. The mean of two analyses gave :— 
SiO. Al10,(¥F10,) UO, PbO BaO SrO CaO P20s H,0 
13°75 . ’ 66°67 0°60 0°28 O13 667 0°29 12°02=99-43 
te rectangular scales with pearly luster were distinguls 
