86 CHEMICAL PROPERTIES OF MINERALS. 
2. NatrouitE.—Fusible in small splinters in the candle 
fame. 
3. ALMANDINE, or bright red GARNET.—Fusible in large 
pieces with ease in the blowpipe flame. 
4, AcTinoLire.—Fusible in large pieces with difficulty in the 
blowpipe flame. 
5. ORTHOCLASE, or common feldspar. Fusible in small 
splinters with difficulty in the blowpipe flame. 
6. Bronzite.—Scarcely fusible at all. 
The color of the flame is an important character in connection 
with blowpipe trials. When the mineral contains sodiwm the 
color of the flame is deep yellow, and this is generally true in 
spite of the presence of other related elements. When sodium 
(or soda) is absent, potassium (or potash) gives a pale violet 
color; calciwm (or lime) a pale reddish yellow ; lithium, a deep 
purple-red, as in lithia-mica 3 strontewm, a bright red, this ele- 
ment being the usual source of the red color in pyrotechny ; 
copper, emerald green ; phosphates, bluish green; boron, yellow- 
ish green ; copper chloride, azure blue. Beads should be exain- 
ined by daylight only, and should be held in such position that 
the color is not modified by green trees or other bright objects 
when examined by transmitted light. Colored flames are seen 
to best advantage when some black object is bevond the flame 
in the line of vision. 
It is also to be noted, in the trials, whether the assay heats 
up quietly, or with decrepitation ; whether it fuses with effer- 
vescence or not, or with intumescence or not; whether it fuses 
to a bead which is transparent, clouded, or opaque; whether 
blebby (containing air-bubbles or not); whether scoria-like or 
not. 
Testing for Water.—The powdered mineral is put at the 
bottom of a closed glass tube, and after holding the extremity 
for a moment in the flame of a Bunsen’s burner, moisture, if 
any is present, will have escaped and be found condensed on the 
inside of the tube, above the heated portion. Litmus or tur- 
meric paper is used to ascertain if the water is acid or alkaline, 
acids changing the blue of litmus paper to red, and alkalies the 
yellow of turmeric paper to brown. 
Testing for an Alkali.—If the fragment of a mineral, heated 
in the platinum forceps, contains an alkali, it will often, after 
being highly heated, give an alkaline reaction when placed, 
after moistening, on turmeric paper, turning it brown. This 
test is applicable to those salts which, on heating, part with a 
portion of their acid and are rendered caustic thereby. Such 
