Chapter Iv—Consolidation of Strata and Petrifaction of Fossils.

Chemical and Mechanical Deposits. — Cementing together of Particles. — Hardening by Exposure to Air. — Concretionary Nodules. — Consolidating Effects of Pressure. — Mineralization of Organic Remains. — Impressions and Casts: how formed. — Fossil Wood. — Goppert’s Experiments. — Precipitation of Stony Matter most rapid where Putrefaction is going on. — Sources of Lime and Silex in Solution.