W. O. Crosby—Pinite in Eastern Massachusetts. 121 
1 Ll. 
SiO, 57924 59520 
Al,O, 23°739 21-628 
FeO 2°826 5°840 
K,O 4°560 6-900 
Na,O 5°283 804 
H,O 3°142 3-490 
MnQ 1°443 not det. 
Cr and Mg traces not det. 
98°917 98°182 
tially identical physically and Spiibae The pinite pebbles 
by the hydration, of feldspathic rocks and minerals, which has 
been denied by some authorities, must apparently be conceded 
in some cases. Of course where derived from a rock holding 
a only as a product of superficial decomposition. The 
acts gs 
s Both of these analyses were made in the Woman’s Laboratory of the Massa- 
chusetts Institute of Technology. 
- Jour. Scr.—Tump Szrizs, = No. 110,—Fxs., 1880, 
