PETROLEUM pure and ſelected.
Cronstedt Min. §§ 147–150. Naptha. Rock oil.
PETROLEUM joined to argillaceous earth.
Cronstedt Min. §§ 157–160. Lithantrax. Pit Coal.
PETROLEUM united to acid of amber.
Cronstedt Min. §§ 133–146. Succinum. Amber.
Many contend that amber has a vegetable origin; but as the point is not very well determined; and as it is found amongſt foſſils, I ſtill retain it here.