Qualitative Tests. 55 
In Closed Tube.—The oxide will yield a white fusi- 
ble sublimate of needle crystals; the sulphide, a black 
sublimate, red when cold. 
Flame —Pale yellow-green. 
With S. Ph.—Dissolved by O. F., and treated on 
coal with tin in R. F. becomes gray to black. 
Interfering Elements. 
Arsenic.—Remove by gentle O. F. on coal. 
Arsenic with Sulphur—Remove by gently heating 
in closed tube. 
Copper—tThe S. Ph. bead with tin in R. F. may 
be momentarily red, but will blacken. 
Lead or Bismuth.—Retard formation of their 
coats by intermittent blast, or by boracic acid. Confirm 
coat by flame, not by S. Ph. 
IN THE WET WAY. 
1. HS precipitates orange-red Sb:Ss from acid so- 
lutions. The precipitate is soluble in HCl, in alkalies, 
and in alkaline sulphides. 
To distinguish between Sb:Os and Sb:0s, add solu- 
tion of AgNOs, in the presence of KOH or NaOH. 
Sb:0: precipitates black, Ag:O, which is insoluble in 
NH:OH; and Sb:O: precipitates white, AgSbOs, which 
is soluble in NH:OH. 
ARSENIC, As. 
WITH THE BLOWPIPE. 
On Smoked Plaster—White coat of octahedral 
crystals. 
On Coal.—Very volatile white coat and strong gar- 
lic odor. The oxide and sulphide should be mixed with 
soda. 
With Bismuth Flux:—On Plaster—Reddisb- 
orange coat, made yellow by (NH:):S. 
On Coal.—Faint-yellow coat. 
