Part 49 (1/2)

(7) with carb. soda. As the preceding.

(8) Special reactions. Gives the chlorine reaction.

Mineral. Vanadinite

Formula. PbCl + 3[.Pb]^{3}[...V]?

Behavior

(1) in gla.s.s-bulb. As pyromorphite.

(2) in open tube. --

(3) on charcoal. The powdered mineral fuses fuses to a black s.h.i.+ning ma.s.s, which in the reducing flame affords a metallic bead. Incrusts the charcoal first with a white film of PbCl and afterwards with PbO.

(4) in forceps. As pyromorphite.

(5) in borax. Dissolves readily to a clear gla.s.s, which, in the oxidizing flame, is yellow, while hot, and colorless when cold. In reducing flame becomes opaque, and on cooling green.

(6) in mic. salt. In oxidizing flame is yellow while hot, becoming paler on cooling. In reducing flame brown while warm, and emerald green when cold.

(7) with carb. soda. On platinum wire fuses to a yellow bead, which is crystalline on cooling. On charcoal yields a b.u.t.ton of metallic lead.

(8) Special reactions. With microcosmic salt and CuO, gives the chlorine reaction. If fused in a platinum spoon with from 3 to 4 times its volume of [.K],[...S]^{2} it forms a fluid yellow ma.s.s having an orange color when cold.

Mineral. Crocoisite

Formula. [.Pb][...Cr].

Behavior

(1) in gla.s.s-bulb. Decrepitates violently and a.s.sumes a dark color.

(2) in open tube. --

(3) on charcoal. Fuses and detonates yielding Cr^{2}O^{3} and metallic lead, and forming an incrustation of PbO on the charcoal.

(4) in forceps. As pyromorphite.

(5) in borax. Dissolves readily and colors the gla.s.s yellow while warm, and green when cold. (See Chromium reaction.)

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

(7) with carb. soda. On platinum foil gives a dark yellow ma.s.s, which becomes paler on cooling. On charcoal yields a metallic b.u.t.ton.