476 
MEASUREMENTS OF CRYSTALS. 
CARBONATE OF MAGNESIA. Page 249. 
Fig. 123. The primary, a rhombohedron. 
P on P . 107° 25' ( Beudant .) 
EPSOM SALT. Figs. 124 and 125. Page 251. 
Fig. 124. The primary, a right rhombic 
prism nearly rectangular. 
M on M'. 90°30 / 
Fig. 125. 
M or M/ on l . 129 14 
l on l .. 126 52 
MAGNESIAN CARBONATE OF LIME. Figs. 
126 to 128 inclusive. Page 252. 
Fig. 126. The primary, a rhombohedron. 
P on P . loeois 7 
MAGNESIAN CARBONATE OF LIME. 
Fig. 127. Bent crystals found in Herki¬ 
mer and Niagara counties. 
Fig. 128. A twin formed as in Fig. 90. 
QUARTZ. Figs. 129 to 183 inclusive. Page 257. 
Fig. 129. The primary, a rhombohedron. 
P / on P / from 94° 15' to 94°24' 
Fig. 130. A common secondary form, a 
six-sided prism, terminated by six- 
sided pyramids. 
P on r, P' on P, r on z' or P on z 140°40 / 
ronP.. 120° O' 
Fig. 131, et seq. 
P on s or z on s . 151° T 
P on z or P' on P .... 133 48 
r on s or P ons. 142 0 
