(6) in mic. salt. --

(7) with carb. soda. --

(8) Special reactions. With bisulphate of pota.s.sa in the gla.s.s-bulb evolves nitrous fumes.

Mineral. Polyhalite

Formula. [.K][...S]+[.Mg][...S]+2[.Ca][...S]+2[.H]

Behavior

(1) in gla.s.s-bulb. Gives off water.

(2) in open tube. --

(3) on charcoal. Fuses to a reddish bead, which in the reducing flame solidifies and shrinks to a hollow crust.

(4) in forceps. On platinum wire fuses and colors the flame yellow from a small quant.i.ty of soda.

(5) in borax. Dissolves with ebullition to a clear gla.s.s, which is slightly colored by iron, and when saturated become opaque on cooling.

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

(7) with carb. soda. Fuses. The alkalies are absorbed by the charcoal leaving the lime and magnesia infusible on the surface.

(8) Special reactions. The alkaline ma.s.s when laid on silver gives a sulphur reaction.

SODA.

Mineral. Rock-salt

Formula. NaCl.

Behavior

(1) in gla.s.s-bulb. Fuses to a clear liquid

(2) in open tube. --

(3) on charcoal. Fuses, is absorbed by the charcoal and partially volatilized incrusting the charcoal around.

(4) in forceps. Fuses with great ease and colors the flame yellow.

(5) in borax. --

(6) in mic. salt. --

(7) with carb. soda. --

(8) Special reactions. Gives the chlorine reactions.

Mineral. Natron

Formula. [.Na][..C] + 10[.H]

Behavior

(1) in gla.s.s-bulb. Fuses, with the evolution of water.

(2) in open tube. --

(3) on charcoal. Fuses, and is absorbed into the pores of the charcoal.

(4) in forceps. Fuses and behaves as the preceding.

(5) in borax. --

(6) in mic. salt. --

(7) with carb. soda. --

(8) Special reactions. Dissolves in acid with violent effervescence.

Mineral. Soda-nitre

Formula. [.Na][.....N].

Behavior

(1) in gla.s.s-bulb. Fuses and if strongly heated evolves nitrous fumes.

(2) in open tube.

-- (3) on charcoal.

Deflagrates and is absorbed into the charcoal.

(4) in forceps. Deflagrates on platinum wire, coloring the flame yellow.

(5) in borax. --