Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 2 
Fig. 3 
Fig. 
Fig. 
LIST OF FIGURES. 
A basal section of microcline from the Notch, as seen between crossed 
“Nicol prisms—page 102. 
A section of fibrolite schist from the Notch, as it appears between crossed 
Nicol prisms—pages 107 and 216. 
Staurolite in a section of the staurolitic slate, as it appears with a single 
Nicol prism. The simple character and excessive impurity of the 
crystals are shown—page III. 
A section of diabase from Dixville notch. Concretions of chlorite are 
shown, which between crossed Nicols are traversed by a dark cross, 
the arms of which are parallel to the planes of the Nicol prisms— 
page 121. 
Apatite crystals in a section of gabbro from Waterville—pages 123 and 
167. 
PLATE IX. 
A section of diabase from East Hanover—page I50. 
A crystal of labradorite in a section of labradorite porphyry from Ossi- 
pee. The fractured and recemented character of the crystal, as it 
appears in polarized light, is shown—page 155. 
A crystal of augite in a section of the olivine diabase from Campton 
falls, showing a concentrically banded structure in polarized light— 
page 158. 
An altered olivine crystal, as it appears in a section of the olivine dia- 
base from Campton falls, with polarized light—page 158. 
Hornblende in a section of porphyritic diorite from Campton falls, as it 
appears with a single Nicol prism—page 161. 
Hornblende and augite associated together in a section of diorite from 
North Lisbon. The prisms are parallel. The hornblende is fresh 
and unaltered, while the augite has decayed and been removed, and 
its place has been filled by an aggregate—page 162. 
PLATE X. 
A section of gabbro from Waterville, as it appears in polarized light— 
page 167. 
A section of quartz porphyry from Mt. Lyon in ordinary light—page 179. 
The same section in polarized light, with lines indicating the directions 
in which the planes of elasticity cut the section—page 179. 
A crystal of orthoclase, which is twinned according to the Carlsbad and 
Baveno systems, in a section of the quartz porphyry from Groveton 
page 180. 
A section of a hornblende granite from Colebrook, showing the rela- 
tionship between the quartz and feldspar in regard to the order of crys- 
tallization—page 191. 
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