Stone marrow.

§ 117.

ARGILLA (argillaceous earth) contaminated by vegetable alkaly and ſulphur, or at leaſt by the acid of ſulphur.

Cronstedt Min. § 124. 2. b. Minera aluminis romani.

Alum ore.

It certainly contains vitriolic acid[[46]], and perhaps, alſo, a ſmall portion of ſulphur. The vegetable alkaly ſufficiently ſhews its volcanic origin.

§ 118.

ARGILLA (argillaceous earth) contaminated by ſiliceous matter, pyrites, and petroleum.

Cronstedt Min. § 124. 2. c. Schiſtus aluminaris[[47]].

Alum ſlate.