464 APPENDIX. AIKIN's, MINERAL SYSTEM in 1815. Class I.—Non-Metallic Combustible Substances'. 1. Combustible with flame. Mineral Oil. 2. Combustible without flame. Graphite. Class II.—Native Metals, and Metalliferous Minerals. Order I Volatilisable, wholly or in part, by the blowpipe oh charcoal, into a vapour, which condenses in a pulverulent form on a piece of charcoal held over it. 1. Entirely, or almost entirely volatilisable. Lustre metallic. Native Arsenic. Lustre non-metallic. Cinnabar. 2. Partly volatilisable; the residue affording metallic grains with borax, on charcoal. ; Lustre metallic. Silver-white Cobalt-ore. , Lustre non-metallic. Red Silver-ore. 3. Partly volatilisable; the residue not reducible to the metallic state. Lustre metallic. Common Iron-pyrites. Lustre non-metallic. Red Cobalt-ochre. Order II-
