Qualitative Tests. 77 
sulting gray or brown film may be turned crimson when 
moistened with conc. H:SOs, and gently heated. 
On Coal with Soda.—Thoroughly fuse in R. F. 
Place on bright silver, moisten, crush, and let stand. 
The silver will be blackened. 
Flame.—Green. 
In Open Tube.—Gray sublimate fusible to clear 
drops. 
With H:SOs(conc.).—Boiled a moment, there re- 
sults a purple-violet solution, which loses color on fur- 
ther heating or on dilution. 
IN THE WET WAY. 
1. HS precipitates brown TeS: from acid solu- 
tions. Soluble in (NH:):S. 
2. Boiled with concentrated H:SO: there results a 
purple-violet solution, which fades upon further heat- 
ing or dilution. 
Confirm.—By blowpipe tests. 
TIN, Sn. 
WITH THE BLOWPIPE. 
On Coal.—O. F. The oxide becomes yellow and 
luminous. 
R. F. A slight coat, assisted by additions of sul- 
phur or soda. 
With Cobalt Solution.—Moisten the coal in front 
of the assay, with the solution, and blow a strong R. F. 
upon the assay. The coat will be bluish green when 
cold. 
With CuO in Borax Bead.—A faint-blue bead is 
made reddish brown or ruby-red by heating a moment 
in R. F. with a tin compound. 
Interfering Elements. 
Lead or Bismuth Alloys.—It is fair proof of tin if 
such an alloy oxidizes rapidly with sprouting and can- 
not be kept fused. 
