in open tube. --

(3) on charcoal. Is infusible. Assumes a deep brown color.

(4) in forceps. V.

(5) in borax. Gives the iron and manganese-reaction.

(6) in mic. salt. As in borax.

(7) with carb. soda. As magnesite, but the residual mass has a dark
color from iron and manganese.

(8) Special reactions. Dissolves with effervescense in warm HCl. With
carbonate of soda and nitre gives a
manganese-reaction.

* * * * *

ALUMINA.

* * * * *

Mineral. Sapphire
Corundum
Emery

Formula. [...Al=].

Behavior

(1) in glass-bulb. --

(2) in open tube. --

(3) on charcoal. --

(4) in forceps. V.

(5) in borax. In fine powder dissolves slowly to a colorless
glass.

(6) in mic. salt. As in borax.

(7) with carb. soda. --

(8) Special reactions. In fine powder moistened with cobalt-solution
and heated yields a blue color.

* * * * *

Mineral. Websterite

Formula. [...Al][...S] + 9[.H].

Behavior

(1) in glass-bulb. Gives off water, and, when heated to incipient
redness, sulphurous acid.

(2) in open tube. --

(3) on charcoal. Gives off water and SO^{3}, leaving an infusible
mass.

(4) in forceps. V.

(5) in borax. Behaves as alumina.

(6) in mic. salt. As in borax.

(7) with carb. soda. Yields an infusible mass, which laid on silver
and moistened, produces a black stain.

(8) Special reactions. Fused with potassa in platinum has no action on
silver. Cobalt-solution produces the alumina
reaction.

* * * * *

Mineral. Native Alum

Formula. [.R][...S] + [...Al][...S]^{3} + 24[.H].

Behavior

(1) in glass-bulb. Intumesces greatly and gives off much water.
Strongly heated, evolves SO^{3}, which reddens
litmus.

(2) in open tube. --

(3)