]).

(5) in borax. As the preceding.

(6) in mic. salt. As the preceding.

(7) with carb. soda. Forms a slaggy mass.

(8) Special reactions. --

* * * * *

Mineral. Siderite

Formula. [.Fe][..C].

Behavior

(1) in glass-bulb. Occasionally decrepitates. Gives off CO^{2} and
turns black and magnetic.

(2) in open tube. --

(3) on charcoal. As in glass bulb.

(4) in forceps. Behaves similarly to the magnetic oxide.

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

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

(7) with carb. soda. Behaves as an oxide. With nitre and carbonate of
soda on platinum generally gives the manganese
reaction.

(8) Special reactions. In acid dissolves with effervescense.

* * * * *

Mineral. Copperas

Formula. [.Fe][...S] + 7[.H].

Behavior

(1) in glass-bulb. Gives off water, and, when strongly heated,
SO^{2} and SO^{3}, which reddens litmus paper.

(2) in open tube. Evolves water and SO^{2}, which may be
recognized by its odor.

(3) on charcoal. Loses water and SO^{2}, and is converted into
[...Fe=].

(4) in forceps. Gives off H and SO^{2}, and then behaves as the
magnetic oxide.

(5) in borax. The roasted mineral affords an iron reaction.

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

(7) with carb. soda. Forms sulphide of sodium and oxide of iron. The
former is absorbed into the charcoal, and if cut
out and laid upon silver and moistened gives the
S reaction.

(8) Special reactions. If dissolved in water, and a strip of
silver-foil be introduced into the solution, the
metal remains untarnished.

* * * * *

Mineral. Vivianite

Formula. [.Fe]^{3}[.....P] + 8[.H].

Behavior

(1) in glass-bulb. Gives off water.

(2) in open tube. --

(3) on charcoal. Froths up and then fuses to a grey metallic
bead.

(4) in forceps.