The whole of this portion of the work is abundantly illustrated with well-executed figures of all the characteristic species that distinguish the several periods, mostly drawn from American examples.
Dynamical Geology.—This particular branch of the subject is made less prominent than usual in geological works, but it will not be found lacking in any point.
The subject is presented in the following order:—
1. Life as an agent in protecting, destroying, and making rocks.
2. Cohesive Attraction.
3. The Atmosphere as a mechanical agent.
4. Water as a mechanical agent.
5. Heat as an agent in volcanic phenomena, igneous eruptions, metamorphism, veins, etc.
6. Movements of the earth's crust, plication of strata, origin of mountains, earthquakes, etc.
7. Chemistry of Rocks.