MAGNESIA aerata (common magneſia) united with ſiliceous matter. This efferveſces with acids, and not unfrequently ſtrikes fire with ſteel.
MAGNESIA intimately united with ſiliceous matter. The ſoluble part is ſlowly taken up by acids, without efferveſcence.
Cronstedt Min. §§79–83. and perhaps § 102–105 alſo; but I have not yet ſubmitted the aſbeſti to the liquid analyſis.
Soaprock. Serpentine.
MAGNESIA united to argillaceous, ſiliceous, and pyritical matters.
M. Monnet diſcovered this, and the next ſpecies.
MAGNESIA united to argillaceous, ſiliceous, and pyritical matters, and likewiſe contaminated by petroleum.