CLASS III.
INFLAMMABLES,
OR
BITUMINA.
To this head we refer all foſſils containing phlogiſton in ſuch great abundance, that under proper management they are inflammable. The Genera are obviouſly very few, and accurately ſpeaking there is only one Genus. But ſince phlogiſton is so very ſubtle as not by itſelf to become the object of our ſenſes, it will perhaps be adviſeable to conſider its more ſimple combinations as Genera: this has long been done ſo far as reſpects the metals, by univerſal conſent.
SULPHUR.
This name may be given to any acid coagulated by phlogiſton into a ſolid form. If all metals conſist of certain radical acids ſaturated with phlogiſton, as is highly probable, and with reſpect to arſenic is indubitably proved; then metals ought to find a place here. But until this theory be eſtabliſhed by numerous experiments, we ſhall only rank under this head the compounds which have not a metallic nature.
PHLOGISTON ſaturated with vitriolic acid.
Cronstedt, Min. § 151. Common Brimſtone. Sulphur.