Earth of alum neither diſſolves ſulphur, nor decompoſes ſal ammoniac.

§ 113.

ARGILLA (argillaceous earth) united to ſiliceous matter only.

Cronstedt Min. §78. Argilla porcellana. Porcelain clay.

Pipe clay.

I never examined any clay which did not contain a large quantity of ſiliceous earth; generally more than half its weight[[44]].

§ 114.

ARGILLA (argillaceous earth) united to ſiliceous and irony matter.

Cronstedt Min. §§ 87 and 90. Bole. Dye-earth.

Clay.