A System of Instruction in the Practical Use of the Blowpipe Part 29

(8) Special reactions. As the preceding.

Mineral. Barytocalcite.

Formula. [.Ba][..C] + [.Ca][..C].

Behavior

(1) in gla.s.s-bulb. As in the preceding.

(2) in open tube. --

(3) on charcoal. In powder frits together, but does not fuse.

(4) in forceps. Colors the flame green in the centre and red towards the point.

(5) in borax. Dissolves with effervescence. In large quant.i.ties gives a semi-crystalline bead.

(6) in mic. salt. As in borax, but the saturated bead is milk-white.

(7) with carb. soda. Fuses, and is partially absorbed leaving the lime on the surface.

(8) Special reactions. As witherite.

LIME.

Mineral. Gypsum

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

Behavior

(1) in gla.s.s-bulb. Turns white, giving off water and being converted into plaster of Paris.

(2) in open tube. --

(3) on charcoal. In the reducing flame forms CaS, which has an alkaline reaction on test paper, and gives a sulphur-reaction when laid on silver and moistened.

(4) in forceps. Fuses with difficulty to a bead, coloring the flame red.

(5) in borax. Dissolves to a clear bead, which gives the lime- reaction.

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

(7) with carb. soda. Behaves as lime. The alkaline ma.s.s laid on silver and moistened gives the sulphur-reaction.

(8) Special reactions. Gives the sulphuric-acid reaction.

Mineral. Apat.i.te { Cl Formula. [.Ca]{ -- +3[.Ca]^{3}[.....P]

{ Fl Behavior

(1) in gla.s.s-bulb. Occasionally decrepitates and gives off some water.

(2) in open tube. --

(3) on charcoal. --

(4) in forceps. IV. Previously dipped in SO^{3} colors the flame green, afterwards red.

(5) in borax. Dissolves easily and when in some quant.i.ty gives an opaline bead.

(6) in mic. salt. Gives the lime-reaction.

(7) with carb. soda. Is infusible. The alkali is absorbed, leaving the lime on the on the surface of the charcoal.

(8) Special reactions. With microcosmic salt and oxide of copper, gives the chlorine-reaction. With microcosmic salt in the open tube evolves fluorine.

Mineral. Pharmacolite

Formula. [.Ca]^{2}[.....As] + 6[.H].

Behavior

(1) in gla.s.s-bulb. Gives off water, and emits an a.r.s.enical odor.

(2) in open tube. --

(3) on charcoal. Fuses to an opaque bead and emits a strong smell of a.r.s.enic.

(4) in forceps. Fuses to a translucent violet colored bead, the color being due to cobalt. Colors the flame blue at first, then faintly red.

(5) in borax. Dissolves readily to a bead strongly colored by cobalt, which obscures the lime-reaction.

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

(7) with carb. soda. Fuses, and emits As. The alkali is then absorbed by the charcoal, as in the preceding.

(8) Special reactions. --