64 Qualitative Tests. 
moved from the slag and be submitted to either the S. 
Ph. or the flame test. 
IN THE WET WAY. 
1. HN.sOH produces a deep-blue solution. 
2. NaOH and KOH when added to saturation 
precipitate blue Cu(OH.):, insoluble in excess. When 
boiled the precipitate changes to black CusO:(OH):. Or- 
ganic substances generally prevent the formation of 
this precipitate. 
3. Fe and Zn precipitate metallic copper from 
cupric solutions. 
FLUORINE, F. 
WITH THE BLOWPIPE. 
Etching Test.—If fluorine be released it will cor- 
rode glass in cloudy patches, and in presence of silica 
there will be a deposit on the glass. According to the 
refractoriness of the compound the fluorine may be re- 
leased— : 
(a) In closed tube by heat ; 
(b) In closed tube by heat and KHSOs; 
(c) In open tube by heat and glass of 8. Ph. 
With Conc. H:SOs and 8iO:—If heated, and the 
fumes condensed by a drop of water upon a platinum 
wire, a film of silicic acid will form upon the water. 
3 IODINE, I. 
WITH THE BLOWPIPE. 
With S. Ph., saturated with CuO.—Treated at the 
tip of the blue flame, the bead is surrounded by an in- 
tense emerald-green flame. 
In Matrass with KHSOs—Violet, choking vapor 
and brown sublimate. 
In Open Tube, with equal parts Bismuth Oxide, 
Sulphur, and Soda.—A brick-red sublimate. 
With Starch Paper.—The vapor turns the paper 
dark purple. . 
