These coprolites, as well as the limestone where they are found, contain a trace of animal matter, as ammonia is disengaged at a red heat.

Muriatic acid dissolves the greater part with slight effervescence. Ammonia throws down from the solution a copious gelatinous precipitate of phosphate of lime; and in the remaining fluid, oxalate o ammonia throws down oxalate of lime. The matter left undissolved by the muriatic acid is inflammable, leaving a small siliceous residue, and appears to be bituminous matter derived from the matrix. There is no magnesia, sulphur, nor fluorine.