tion of, 127; characters of the normal rocks, 
138; three orders of normal deposits, 139 ; 
coup d’ceil of the normal rocks, 198; changes 
produced by the contact of normal and abnor- 
mal masses, 201. 
Nummulite, internal structure of the 180. 
Obsidian, 97. 
Octahedron, the regular, the type of the mono- 
metric system, 47; various figures derivative 
from the, 48 ; the square, the basis of the di- 
metric system, 49; the rhombic, the funda- 
mental form of the trimetric system, 50. 
Oil-bath, the, 28. 
Old Floetz limestone, the, general geological 
characters of, 158, 159. 
Oligoclase, 77. 
Olivine, 72. 
Oolite, 103. 
Oolitic formation, the, 166; the lower oolite, 
167; order of the strata as found in England, 
168. See the Jura formation. 
Ophite, 100. 
Ore, alternation of layers of, with gangue, 131 ; 
veins and beds of, profuse in the bottom series, 
141. 
Oreography, province of, 88, 113; general, 113 ; 
special, 138. 
Organisms, chemical examination of animal and 
vegetable, 26; progressive improvement and 
perfection of, 137. 
Orpiment, 67. 
Ostraceee of the cretaceous different from those 
of the Jura, 181. 
Ostrea, the, first appear in the Jura, 171; gene- 
ra allied to, ib. 
Oxy-hydrogen blowpipe, use of the, 23. 
Oxydes, nature of, and description of several, 
67; economical uses of the, 83. 
Oxygen gas, properties of, 12 ; method of obtain- 
ing pure, ib. ; combination of, with hydrogen, 
21; use of, in chemical analysis, 31. 
Paleontology, 135; relation of, to geology, 138. 
Palewotherium, the, 191. 
Palatinate, the, extensive coal basin in, 154. 
Paris, tertiary basin of, 125; order of the strata, 
and enumeration of the principal fossils of the 
caleaire grossier in the, 185; the Paris ter- 
tiary rests on the cretaceous, 186; artesian 
well at Paris, 198. 
Paris, plaster of, 79. 
Pearlstone, 97. 
Peat, division of, into wood, leaf, and moss, 
195. 
Pebble beds, 113. 
Pericline, 77. 
Petrifactions, nature of, and method of classify- 
ing, 134. 
Petrography, province of, 88 ; general, 89 ; spe- 
cial, 90. 
Phonolite, 207. 
Phosphates of the alkalies, 81. 
Phosphorus, process of obtaining, 15. 
Picrosmine, 72. 
Pipe clay, 111. 
Pitchstone, 97. 
Plains, limit between, and valleys not well de- 
fined, 118; divided into depressed, proper, and 
elevated, ib. 
Plants, masses produced by the decomposition of, 
195. 
666 
INDEX TO CHEMISTRY, MINERALOGY, AND GEOLOGY. 
Plaster of Paris, 79. 
Plesiosaurus, the, 175. 
Pliocene, the older and newer, 190. . 
Plumbago, 56. 
Plutonic rocks, 201. 
Pneumatic tub or trough, description. of the, 14. 
Porcelain, composition of, 83; porcelain clay, 
111. 
Porphyry, silicious, principal varieties of, 92 ; 
eurite and clay-stone, 96 ; greenstone, 99 ; con- 
glomerate, 108; rocks, 204; principal fea- 
tures and distribution of, ib. 
Potter’s clay, 111. 
Prehnite, 75. 
Press, the pharmaceutical extract, 39. 
Primary middle rocks, characters of the, 143 ; 
two formations distinguishable, ib. 
Prism, an oblique rhombic, the primary form of 
the monoclinic system, 51; an oblique rhom- 
boidal, the basis of the triclinic system, ib. 
Provence, the calcaire grossier formation in, 
186. 
Prussic acid, apparatus for making, 38. 
Pterodactyles, the, the most extraordinary forms 
known to zoologists, 175. 
Pumice, 97 ; pumice conglomerate, 110. 
Pyramid, the double six-sided, the primary form 
of the hexagonal system, 51. 
Pyrites, signification of, and description of seve- 
ral kinds, 65. 
Pyrmont, valley of, relations of the strata of the, 
123. 
Pyrolusite, 70. 
Pyromorphate, 80. 
Pyroxene, 72; characters of the, rocks, 97, 205 ; 
distribution of, rocks, 206. 
Quadersandstein, the, a subdivision of greensand, 
characters of, 176; nature of the soil produced 
by the weathering of, 178. 
Quadrumana, fossil, found in the European ter- 
tiary, 193. 
Quartz, 69 ; quartz rock proper and argillaceous 
quartz, 91; sandstone, 107 ; sand, 112 ; quartz 
rock found in the transition-slate formation, 
144; quartz sandstone present in the Devo- 
nian system, 147. 
Rain, decomposition of rocks by, 199. 
Real’s hydrostatic press, 39. 
Realgar, 67. 
Red sandstone, the, of the secondary middle 
ceries, characters and localities of, 158. 
Rennes and Nantes, formation of the country 
between, 147. 
Retort, the, method of arranging, for distillation, 
ae 
Rhenish transition rocks, succession of the strata 
of the, 148. 
Rhinoceros, the, found only in the upper tertiary 
beds, 191. 
Rhizopoda, abundance of, in the cretaceous 
formation, 179; characters of various groups 
of, 180. 
Rock salt, 80 ; rock salt formation and its fos- 
sils, 161, 165. 
Rocks, definition of the term, 88; distinction 
between isonomic and heteronomic, 89; va- 
rious conditions of isonomic, 90; silicious, 91 ; 
micaceous, 92; feldspathic, 95; pyroxene, 97 ; 
trap, 98; schiller spar and serpentine, 100: 
amphibolie and calcareous, 101; magnesian, 
