Saline Iron with an organic Form.
Human bodies have ſometimes been found indurated and penetrated by vitriol of iron; so likewiſe have plants, their roots eſpecially. In the open air they moulder away.
Mild Calcareous Earth with an organic Form.
This conſtitutes the ſubſtance of moſt petrefactions.
Clay with an organic Form.
It is remarkable, that petrefactions found in clay are compreſſed, although, in ſubjacent calcareous ſtrata, they preſerve their natural figure. Similar compreſſed petrefactions are alſo found in the marly ſchiſtus.