Geology and Mineralogy. 413 
appearance of massive eruptive rock. Other rocks of same 
phosphate region are gneisses, quartzites, and crystalline lime- 
stones. The apatite occurs in man in connecti 
green crystal affor 
i i 
G.=3-385 138 rey reg ore os ook Te $17=100°03 
Other varieties also occur, sometimes in crystals of large dimensions. 
The pyroxene is often partially or wholly altered to uralite. The 
change appears to have begun at the surface of the erystal and 
gradually extended inward; at the surface the hornblende prisms 
are mostly parallel to the vertical axis, within bey run in all direc- 
tions and are sometimes in radiating groups. One erystal had a 
center of glassy pyroxene (A), surrounded by a dull pale material 
(B), and thi by an aggregation of hornblende (uralite) prisms (C). 
Analyses of these three portions afforded :— 
SiO. Al,0, Fe.0,; FeO MnO CaO MgO K,O Na,O ign. 
A. 50°87 : . : 0°22 1°44: 
1:96 O15 2444 15°37 0°50 : 
x 5090 4°82 144 1:36 O15 2439 15°27 015 0-08 1:20=10006 
| 6282 3-21 207 2-71 028 16°39 1904 0-69 090 240= 99°51 
C € specific gravity was for A=3°181, for B=3'205, and for 
-=3°003. The change in composition from A to C is seen to 
in i though 
there is also a loss of alumina and slight gain in alkalies. 
"e , ght gain ina 
Dr. Harrrington also discusses the relations of the phosphate 
