56 Qualitative Tests. 
In Open Tube.—White sublimate of octahedral 
crystals. Too high heat may form brown suboxide or 
red or yellow sulphide. 
In Closed Tube.—May obtain white oxide, yellow 
or red sulphide, or black mirror of metal. 
Flame.—Pale azure-blue. | 
Interfering Elements. 
Antimony.—Heat in closed tube with soda and 
charcoal, treat resulting mirror in O. F. for odor. 
Cobalt or Nickel.—Fuse in O. F. with lead and 
recognize by odor. 
Sulphur.—(a) Red to yellow sublimate of sulphide 
of arsenic in closed tube. 
(b) Odor when fused with soda on coal. 
IN THE WET WAY. 
1. HS precipitates yellow As:Ss best from HCl 
solutions. Soluble in alkalies and alkaline sulphides, 
insoluble in HCl. 
2. H:S precipitates yellow, As:Ss from acid solu- 
tions after heating solution and passing gas for some 
time. 
3. AgNOs precipitates yellow AgsAsOs or reddish- 
brown AgsAsOs, soluble in dilute acids, ammonia, and 
ammonia salts. s 
4. CuS0Os precipitates yellowish-green Cus(AsOs)s 
or greenish-blue, CuHAsOs, soluble in NH.OH and 
NH.Cl. 
5. Ammonium magnesia mixture precipitates 
white MgN HsAsO.:. 
| BARIUM, Ba. — 
WITH THE BLOWPIPE. 
On Coal, with Soda.—F uses and sinks into the coal. 
Flame.—Yellowish green, improved by moistening 
“with HCl. . 
