A System of Instruction in the Practical Use of the Blowpipe Part 56

(5) in borax. --

(6) in mic. salt. --

(7) with carb. soda. --

(8) Special reactions. --

SILVER.

Mineral. Native silver

Formula. Ag.

Behavior

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

(2) in open tube. --

(3) on charcoal. Fuses and in a strong oxidizing flame forms an incrustation of dark brown oxide on the charcoal. If any antimony be present, it affords a crimson incrustation.

(4) in forceps. --

(5) in borax. Gives the silver reactions.

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

(7) with carb. soda. --

(8) Special reactions. --

Mineral. Antimonial silver

Formula. Ag^{2}Sb.

Behavior

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

(2) in open tube. Gives off dense white fumes, which are partly deposited in the tube.

(3) on charcoal. Fuses, fumes strongly, forming a white incrustation, and when the antimony is nearly expelled a crimson one, a nearly pure silver bead remains.

(4) in forceps. --

(5) in borax. The incrustation formed on charcoal gives an antimony reaction.

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

(7) with carb. soda. As alone on charcoal.

(8) Special reactions. --

Mineral. Silver glance

Formula. AgS.

Behavior

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

(2) in open tube. Gives off sulphurous acid.

(3) on charcoal. Gives off SO^{2} and is reduced to metallic silver. If impure, a small quant.i.ty of slag also remains.

(4) in forceps. --

(5) in borax. The residual slag (if any) obtained upon charcoal gives an iron reaction.

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

(7) with carb. soda. As alone on charcoal. The alkaline ma.s.s gives a sulphur reaction on polished silver.

(8) Special reactions. --

Mineral. Stephanite

Formula. [,Ag]^{6}[,,,Sb].

Behavior

(1) in gla.s.s-bulb. Decrepitates, fuses and gives a slight sublimate of sulphide of antimony.

(2) in open tube. Fuses and gives off SO^{2} and dense white antimonial fumes.

(3) on charcoal. Fuses and incrusts the charcoal with antimonious acid, leaving Ag with some antimony. If the flame be continued, a red incrustation is formed and finally a bead of pure silver remains surrounded by a small slag.

(4) in forceps. --