UC-NRLF
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/BERKELEY
LIBRARY
I UNIVERSITY OF
\CALIFORNIA
EARTH
Geology
THE ELEMENTS OF BLOWPIPE
ANALYSIS
THE
ELEMENTS OF BLOWPIPE
ANALYSIS
BY
FREDERICK HUTTON GETMAN, F.C.S.
INSTRUCTOR IN CHEMISTRY IN THE STAMFORD
HIGH SCHOOL
godt
THE MACMILLAN COMPANY
LONDON : MACMILLAN & CO., LTD.
1899
All rights reserved
BY THE MACMILLAN COMPANY.
Nortoonfi
J. 8. Gushing & Co. - Berwick Sc Smith
Norwood Mass. U.S.A.
PREFACE
THESE few pages are intended to serve
a twofold purpose, — to give the student
a general outline of Blowpipe Analysis,
and to introduce him to the methods of
Determinative Mineralogy.
Every effort has been made to simplify
details so that the book may be used in
both High Schools and Colleges.
Tables for " systematic " examination have
been intentionally omitted, for in the au-
thor's estimation these tend to dull the
student's power of observation, and to make
him place little value upon minute details.
The alphabetic arrangement has been
followed for the sake of convenience when
referring to the book.
819488
Vi PREFACE
The last chapter is not intended to serve
as a key to determining the minerals therein
described, but rather it is added to give
the student exercise in Blowpipe Analysis,
and at the same time to point out the
methods of Determinative Mineralogy.
Finally, the author would acknowledge his
indebtedness to the following works : " Man-
ual of Qualitative Analysis," Fresenius;
"Qualitative Chemical Analysis," Venable;
Roscoe and Schorlemmer's " Treatise on
Chemistry"; Foye's " Hand- Book of Min-
eralogy"; Dana's "Mineralogy"; Kobell's
"Tafeln zur Bestimmung der Mineralien";
etc.
FREDERICK HUTTON GETMAN.
STAMFORD, CONN.,
Feb. 22, 1899.
TABLE OF CONTENTS
CHAPTER I
PAGE
Apparatus and Reagents 1-7
CHAPTER II
General Outline of Blowpipe Analysis 8
Definitions 9
Examination on Charcoal Alone 10
Examination on Charcoal with Sodium Carbonate . . 13
Examination in Tube with Sodium Carbonate and Charcoal . 15
Examination on Platinum Wire 16
Examination in Borax Bead 17
Examination with Cobalt Nitrate 20
CHAPTER III
General Reactions for the Detection of the Metallic Ele-
ments in Simple Compounds 22
Aluminum 23
Antimony 24
Arsenic 25
Bismuth - • • . ' , 25
Cadmium 26
Chromium 26
Cobalt .......... 27
vii
viii CONTENTS
PAGE
Copper 28
Iron 28
Lead 29
Manganese 30
Mercury 30
Nickel 31
Silver 32
Tin 32
Zinc 33
The Alkali Metals 34
Ammonium 34
Potassium 35
Sodium 35
Lithium 36
The Alkaline Earths 36
Barium 36
Calcium 37
Strontium 37
The Acid Elements
37
Borates 37
Bromides 38
Chlorides 38
Fluorides 38
Iodides 39
Nitrates 39
Phosphates 40
Silicates . . . .40
Sulphides . .41
CONTENTS IX
CHAPTER IV
PAGE
Behavior of Some of the Principal Ores before the Blowpipe 43
Ores of Antimony •••'.. . . 46
Ores of Arsenic . . . . "* . . . -47
Ores of Bismuth . » , . . . . . . 48
Ores of Chromium 49
Ores of Cobalt 50
Ores of Copper , , 52
Ores of Iron 57
Ores of Lead 60
Ores of Manganese 63
Ores of Mercury 64
Ores of Nickel 65
Ores of Silver 66
Ores of Tin i . . 69
Ores of Zinc 70
COMPARATIVE TABLES
I. Colors of Coatings on Charcoal 73
II. Flame Colorations , •' 9 73
III. Colors of Borax Beads in oxidizing Flame ... 74
IV. Colors of Borax Beads in reducing Flame ... 75
V. Colors of Microcosmic Salt Beads in oxidizing Flame . 76
VI. Colors of Microcosmic Salt Beads in reducing Flame . 77
FORCEPS
Fig. 5
AGATE MORTAR & PESTLE
Fig. 4
HAMMER
Fig, 6,
3 -CORNERED FIJ_ES
Fig, 7
BLOWPIPE ANALYSIS
CHAPTER I
THE blowpipe was first applied to mineral
analysis in 1733 by Anton Swab, and its
applications have since been improved and
extended by various chemists, among whom
may be mentioned Bergmann, Cronstedt,
Gahn, Berzelius, and Plattner.
Blowpipe. — The common blowpipe of the
jeweller is not particularly well suited to
the operations of blowpipe analysis, since
the flame has often to be kept playing
upon the assay for some time, and the
condensed moisture of the breath would
seriously interfere with the passage of the
« BLOWPIPE ANALYSIS
air through the jet. One of the best and
least expensive forms of blowpipe is shown
in Fig. i. This consists, as is seen from
the illustration, of a conical-shaped tube of
tin closed at the wide end and formed into
a mouthpiece at the small end; soldered
into the tube at the large end, and at
right angles to its axis, is a small brass
tube which terminates in a conical tip
pierced with a very fine hole. With this
pipe it is possible to perform all of the
operations of mineral analysis.
Some little practice is necessary to keep
the flame steady and to take the breath at
the same time.
No rule can well be given to the begin-
ner, but his experience becomes his best
guide.
Bunsen Flame. — Any kind of flame can
be used for the blowpipe, provided it be
BUNSEN FLAME 3
not too small ; but since almost every labo-
ratory to-day is furnished with gas and the
Bunsen burner (Fig. 2), it will only be
necessary to describe the use of the flame
from this source. Upon examining the
Bunsen flame with care, it will be seen that
the flame consists of three distinct parts.
A dark inner cone which consists of gas
not yet raised to the ignition point. Be-
yond this there is a luminous cone, where
combustion is incomplete owing to lack of
oxygen, and outside of this we find the
non-luminous cone where the gas is com-
pletely burned.
This outer envelope is the hottest por-
tion of the flame, and is known as the
" oxidizing " flame because there is an excess
of oxygen which is imparted to substances
placed therein.
The luminous cone is known as the
"reducing" flame, for in it metallic oxides
4 BLOWPIPE ANALYSIS
are reduced, the oxygen being taken up
by the small incandescent particles of car-
bon.
If the air-holes at the base of the Bun-
sen burner be opened, the two inner cones
become elongated, and the flame appears
almost colorless.
The blowpipe enables us to get an oxidiz-
ing and a reducing flame of better form
and greater power. To do this we cut off
the air supply at the base of the burner
and turn off the gas until the flame is
about i cm. high; then upon introducing
the blowpipe, and blowing a strong con-
tinuous jet of air across the Bunsen flame,
we produce an oxidizing flame about 4-5
cm. in length. If the tip of the blowpipe
be held outside of the Bunsen flame, and
the pressure of the stream of air be dimin-
ished, we obtain a reducing flame.
BUNSEN FLAME 5
Supports. — For supports, charcoal, plati-
num, and glass are chiefly used. The
charcoal should be made from some light
wood, such as alder. It should be well
burnt, and should not scintillate or smoke.
The platinum supports are generally in
the form of wire and foil. Platinum-tipped
forceps are frequently employed in blow-
pipe analysis.
Glass is used in the form of tubing.
Hard glass tubing, 3 mm. bore, is drawn
off into ignition tubes 7-8 cm. in length.
Several dozen of these tubes should be
made before commencing the tests of the
next chapter.
Apparatus. — A small agate mortar, 4-5
cm. in diameter, should be provided in
which to grind the samples to be exam-
ined.
The pestle, which should also be of agate,
6 BLOWPIPE ANALYSIS
must be adapted to the mortar in shape
and size.
Two pairs of forceps will also be needed.
One pair should be of steel, and the other
pair of brass, with fine points.
Of other apparatus, the most necessary
is: —
A small hammer and anvil.
Two three-cornered files.
Small piece of cobalt glass, about 5 x 10
cm.
Pocket magnifying lens.
Several small watch glasses — for metallic
beads, etc.
Chemicals. — A list of the principal chemi-
cals is here given : —
Sodium carbonate, Na2CO3.
Borax, Na2B4O7+ ioH2O.
Microcosmic salt, (HNaNH4), PO4 + 8 H2O.
BUNSEN FLAME 7
Cobalt nitrate, Co(NO3)2+5 H2O.
Potassium cyanide, KCN.
Hydrochloric acid, (dilute), HCl + nH2O.
Litmus paper, red and blue.
Brazil-wood paper.
Any other special reagents which may be
needed will be mentioned as required.
CHAPTER II
GENERAL OUTLINE OF BLOWPIPE ANALYSIS
[ABBREVIATIONS : O. F. for oxidizing flame, R. F. for reducing flame,
Ch. for charcoal, Ct. for coating, Bp. for blowpipe.]
IN order to examine a substance before
the blowpipe to determine the presence
or absence of certain elements, it becomes
necessary to arrange a systematic method.
As with all branches of chemical work,
one's success is largely dependent upon
neatness of manipulation and carefulness of
observation.
The following order of observation is
essentially that given by Berzelius : —
1. Examination on charcoal by itself.
2. Examination on charcoal with NazCO3.
8
GENERAL OUTLINE OF BLOWPIPE ANALYSIS 9
3. Examination in ignition tube with
Na2CO8 and charcoal.
4. Examination on platinum wire.
5. Examination in borax bead.
6. Examination with Co(NO3)2.
After having examined a body in these
six different ways, we shall be able to say
what are its principal constituents.
Before describing the method of carrying
out these six different operations, it will be
necessary to give a few definitions of terms
which we shall have frequent occasion to
employ.
Definitions. — Ignition is the heating of a
substance to a high temperature.
Fusion is the heating of a substance to
the melting-point.
Intumescence is the swelling of the sub-
stance upon heating.
10 BLOWPIPE ANALYSIS
Decrepitation is the crackling of a sub-
stance due to the sudden expansion of
combined water upon heating.
Deflagration is the burning of a sub-
stance with explosive violence, generally
due to excess of oxygen.
Incandescence is the white light emitted
by a substance that is infusible when sub-
jected to a high temperature.
Examination on Charcoal alone. — The size
of the assay should be about that of a
mustard seed. This is sufficiently large to
show all of the reactions clearly, and though
a larger piece would exhibit the character-
istic phenomena, yet much more effort is
required. A very small, shallow hole should
be cut in the Ch. to receive the assay. The
Bp. flame should be directed at an angle of
about 30° with the surface of the Ch. Con-
siderable care must be taken lest the hole in
GENERAL OUTLINE OF BLOWPIPE ANALYSIS II
the Ch. is burned too deep and the assay
lost in the coal.
The force of the air from the jet must
also be borne in mind for a strong blast, or
sudden puffs may blow the substance away.
The following changes are to be looked
for: —
a. Whether the substance is volatile or
non-volatile.
Illustrations. Examine before the Bp. on
Ch. some arsenious oxide, As2O3, also some
alumina, A12O3.
b. Whether the substance is fusible or
infusible.
Illustrations. Examine before the Bp. on
Ch. some silver oxide, AgO, also some zinc
oxide, ZnO.
c. Whether the substance is alkaline or
non-alkaline when placed upon moistened
red litmus.
12 BLOWPIPE ANALYSIS
Illustrations. Ignite some calcium car-
bonate, CaCO3, before the Bp. on Ch., and
place residue on moistened red litmus. In
like manner, examine some magnesium car-
bonate, MgCO3.
d. Color of coating on Ch. caused by
combination of metal and oxygen due to
heat of Bp. flame.
Illustrations. Examine some oxide of
lead, PbO, before the Bp. on Ch., also some
oxide of cadmium, CdO.
e. Decrepitation.
Illustration. Examine some sodium chlo-
ride, NaCl, before the Bp. on Ch.
f. Deflagration.
Illustrations. Examine some potassium
nitrate, KNO3, before the Bp. on Ch., also
some ammonium nitrate, NH4NO3.
GENERAL OUTLINE OF BLOWPIPE ANALYSIS 13
g. Intumescence.
Illustration. Examine some alum,
K2A12(S04)4, • :
before the Bp. on Ch.
h. Incandescence.
Illustration. Examine some oxide of
barium, BaO, before the Bp. on Ch.
i. Formation of a metallic bead — color
and malleability.
Illustration. Examine some silver oxide,
AgO, before the Bp. on Ch.
Examination on Charcoal with Na2C03. —
Metallic compounds are often difficult to
reduce with the blowpipe flame alone, and
hence no bead is obtained. In order to
facilitate reduction and the obtaining of a
metallic bead, the substance in a finely
powdered condition is mixed with four
14 BLOWPIPE ANALYSIS
parts of sodium carbonate, Na2CO3, and
ignited before the Bp. on Ch. The me-
tallic compound is decomposed, the metal
being transformed into the carbonate, which
in turn, through the agency of the Ch. and
the heat of the flame, is reduced to the
free metal. Sometimes the reduction is
made easier by adding to the substance
about its own bulk of potassium cyanide,
KCN, which takes up oxygen from the
compound and is converted into potassium
cyanate, KCNO.
The reactions in reducing copper sul-
phate, CuSO4, with Na2CO3 and with KCN
before the blowpipe, are here given : —
CuS04 + Na2C03 = CuC03 + Na2SO4 1
2 CuCO3 + C = 3 CO2 + 2 Cu J
CuSO4 + Na2CO3 = CuCO8 + Na2SO4
CuO + KCN = Cu + KCNO
GENERAL OUTLINE OF BLOWPIPE ANALYSIS 15
After obtaining beads, it is well to obtain
their coatings, for oftentimes it is only in
this way that we can distinguish between
the metals.
Examination in Tube with Na2C03 and
Charcoal. — If the substance in a finely
pulverized condition be mixed with twelve
parts, Na2CO3, and six parts of charcoal
powder and the mixture be placed in an
ignition tube and subjected to heat, the
acid of the substance combines with the
soda and the metal is set free.
If this metal is volatile, a sublimate is
formed in the upper end of the tube.
Mercury deposits in minute globules,
which may be seen with the magnifying
glass. Arsenic forms a ring, which, when
examined with the magnifying glass, is seen
to be made up of minute crystals. Am-
monia is recognized by its characteristic
1 6 BLOWPIPE ANALYSIS
odor, and also by its turning a slip of
moistened red litmus (held over the mouth
of the tube) blue.
Examination on Platinum Wire. — Many
substances possess the property of impart-
ing to the colorless flame of the Bunsen
burner characteristic colors.
The chlorides of these substances exhibit
these flame reactions best, and hence before
applying the flame tests we dip the wire
which serves as a support into hydrochloric
acid and then into the substance. When
the substance has been taken up on the
wire, it is placed in the edge of the long
colorless flame of the Bunsen burner near
the apex, when instantly the flame becomes
tinged with the characteristic color of the
substance.
Illustrations. Sodium compounds color
the flame yellow, and a crystal of potas-
GENERAL OUTLINE OF BLOWPIPE ANAL YSIS I /
sium dichromate appears colorless in the
sodium light.
This sodium reaction is extremely deli-
cate, it being possible to detect with ease
a quantity of a sodium salt less than
innnhnnr of a milligram in weight.
Potassium colors the flame purplish-violet.
Barium colors the flame apple-green.
Strontium colors the flame crimson.
Calcium colors the flame orange-red, dis-
tinguished from strontium, by appearing
gray when seen through blue glass.
Boracic acid colors the flame green when
the substance has been moistened with
glycerine.
Examination in Borax Bead. — Borax,
Na2B4O7, and microcosmic salt,
NaNH4H . P04,
possess the property of dissolving many of
1 8 BLOWPIPE ANALYSIS
the metallic oxides at the temperature of
the Bunsen flame.
For example, with oxide of cobalt, the
following reactions take place with the two
fluxes : —
CoO + Na2B4OT = Co(BO2)2 + 2 NaBO2.
On heating, NaNH4H.PO4, it is decom-
posed into the metaphosphate of sodium,
NaPO8,
CoO + NaPO3 = CoNaPO4.
Now in such cases of solution the me-
tallic oxides impart a characteristic color
to the flux.
The platinum wire is the best support, —
it is heated to incandescence in the Bunsen
flame, and then is quickly dipped into the
borax, when a small globule will adhere, —
this is removed to the flame again when
the borax melts to a clear glassy bead.
While the bead is still melted, touch it to
GENERAL OUTLINE OF BLOWPIPE ANALYSIS 1 9
the finely pulverized substance and replace
in the flame. In a few seconds the small
particles of the substance will have dis-
solved, and the bead will be seen to have
assumed the color characteristic of the sub-
stance. Note the color when hot and then
when cold ; often there is a wide difference.
Then, too, the test should be made in both
O. F. and R. F.
Some analysts prefer to make a small
loop in the end of the wire before taking
up the borax to make the bead. Care
should be taken to see that the bead is
colorless before bringing it in contact with
the substance.
As the depth of color produced is largely
dependent upon the amount of substance
taken, some little caution should be exer-
cised to insure taking up about the same
quantity each time.
Illustrations. Make several beads, and
20 BLOWPIPE ANALYSIS
note the colors characteristic of the follow-
ing oxides: cobalt, nickel, iron, manganese,
chromium, and copper.
The microcosmic salt bead dissolves al-
most every oxide except silica, SiO2, and
this is seen to float about in the melted
mass. This is used as a test for silica.
Examination with Co(N03)2. — If after ex-
amination on the Ch. per se, a white infusible
residue remains, it is moistened with a drop
of cobalt nitrate Co(NO3)2 and re-ignited
before the Bp., when a change of color will
be observed. This change in color is owing
to the fact that the heat of the Bp. flame
decomposes the cobalt nitrate, nitric acid
being driven off, and the remaining CoO
forming with the oxide of the residue a
colored mass.
Illustrations. Ignite before the Bp. on
Ch. the following oxides, — allow to cool,
GENERAL OUTLINE OF BLOWPIPE ANALYSIS 21
add a drop of Co(NO8)2, re-ignite, and note
color, — aluminum, magnesium, zinc, and
calcium.
Care should be taken to thoroughly ignite
before adding the cobalt nitrate solution.
With the six methods of examination just
given almost every simple substance can be
detected, but should any doubt remain, a
few simple tests in the " liquid way " will be
sufficient to substantiate the blowpipe exam-
ination.
CHAPTER III
GENERAL REACTIONS FOR THE DETECTION OF THE
METALLIC ELEMENTS IN SIMPLE COMPOUNDS
FOR the sake of convenience, rather than
for scientific reasons, the following com-
pounds have been arranged in alphabetic
order. Also the oxides of the elements have
been taken, since they exhibit the reactions
to best advantage.
The student should work through care-
fully each one of the tests and satisfy him-
self as to the characteristic reactions of the
various elements, for only in this way can
he expect to recognize the substances when
presented to him as " unknowns." It is
advisable to provide a note-book and rule
it as follows : —
22
GENERAL REACTIONS
BEHAVIOR OF SUBSTANCE
Before Bp.
onCh.
alone
Before Bp.
on Ch. with
NajCO8
In ignition
tube with
Na2CO3and
Ch.
In flame on
platinum
wire
In flame
with borax
bead
After first
ignition
with
Co(NO3)2
-
Remar
Substa
ks
nee __
i. Aluminum, AL03. — Before the Bp. on
Ch. Infusible. No change.
Before the Bp. on Ch. with Na2CO8.
Forms an infusible compound with slight
intumescence.
In ignition tube with Na2CO3 and Ch.
No change. Moisture driven off.
In flame on platinum wire. No change.
Becomes incandescent.
In flame with borax bead. In O. F.
24 BLOWPIPE ANALYSIS
dissolves slowly, forming a colorless glass
which remains so on cooling.
With Co(NO3)2. Mass becomes blue upon
re-ignition.
2. Antimony, Sb203. — Before the Bp. on
Ch. In O. F. volatilizes without change.
In R. F. is reduced and volatilized. White
coating of antimonious oxide deposited on
Ch. Blue tinge imparted to flame.
Before the Bp. on Ch. with Na2CO3.
Readily reduced. ' White brittle bead. Very
volatile, giving characteristic white coat-
ing.
In ignition tube with Na2CO3 and Ch.
Volatilized.
In flame on platinum wire. Volatilized.
Colors flame greenish blue.
With borax bead on platinum wire. In
O. F. dissolves to a colorless glass.
With Co(N03)2
GENERAL REACTIONS 2$
3. Arsenic, As203. — Before the Bp. on Ch.
Very volatile. Strong garlic odor to fumes.
Before the Bp. on Ch. with Na^COs.
Reduced with emission of arsenical fumes.
In ignition tube with Na2CO3 and Ch.
Volatilizes, forming a mirror-like deposit
of metallic As in the cooler part of tube.
In flame on platinum wire
With borax bead on platinum wire
With Co(N03)2_.
4. Bismuth, Bi203. — Before the Bp. on
Ch. Yields a coating — orange-yellow
when hot, lemon-yellow when cold. The
yellow coating usually has a white outline.
Before the Bp. on Ch. with Na2CO3.
Easily reduced to metallic bismuth. Yellow
bead brittle, but less so than antimony.
In ignition tube with Na2CO3 and Ch.
26 BLOWPIPE ANALYSIS
In flame on platinum wire
With borax bead on platinum wire.
In O. F. small quantity dissolves to a clear
yellow glass, which becomes colorless when
cold
With Co(NO3)2 _.. ._
5. Cadmium, CdO. — Before the Bp. on
Ch. Gives a coating on the coal. Red-
dish-brown when cold. Very volatile.
Before the Bp. on Ch. with Na2CO3.
Readily reduced. The metal volatilizes
easily, giving the characteristic coating.
In ignition tube with Na2CO3 and Ch.
In flame on platinum wire
With borax bead. In O. F. dissolves to a
clear yellowish bead, colorless when cold.
With Co(N08)2
6. Chromium, Cr203. — Before the Bp. on
Ch. No change.
GENERAL REACTIONS 2/
Before the Bp. on Ch. with Nc^COg.
Cannot be reduced. Soda sinks in Ch.
and a green colored mass remains.
In ignition tube with Na2CO3 and Ch.
In flame on platinum wire
With borax bead. Dissolves slowly but
colors intensely. Yellow while hot, green
when cold.
With microcosmic salt bead. Colors red
when hot, green when cold.
With Co(NO3)2
7. Cobalt, CoO. — Before the Bp. on Ch.
In O. F. unchanged. In R. F. is reduced
to the metal and is magnetic.
Before the Bp. on Ch. with Na^COg.
Reduced to a gray magnetic mass.
In ignition tube with Na^COa and Ch.
In flame on platinum wire
28 BLOWPIPE ANALYSIS
With borax bead on platinum wire.
In O. F. colors very intensely blue, both hot
and cold.
With Co(NO3)2
8. Copper, CuO. — Before the Bp. on Ch.
Fuses to a black globule, which can be
reduced with some difficulty.
Before the Bp. on Ch. with Na2CO3.
Readily reduced to metallic bead, which is
red in color, hard, malleable.
In ignition tube with Na2CO3 and Ch.
In flame on platinum wire. Colors flame
emerald-green.
With borax bead on platinum wire. In
O. F. green when hot, blue when cold.
With Co(N03)2
9. Iron, Fe203. — Before the Bp. on Ch.
In O. F. unchanged. In R. F. becomes
black and magnetic.
GENERAL REACTIONS 29
Before the Bp. on Ch. with Na2CO3
Reduced to a metallic powder, magnetic.
In ignition tube with Na2CO3 and Ch.
In flame on platinum wire
With borax bead on platinum wire.
In O. F. red while hot, yellow when cold.
With Co(NO3)2
10. Lead, PbO. — Before the Bp. on Ch.
Easily reduced to the metal, bead very
malleable. Coating yellow, surrounded by
white ring.
Before the Bp. on Ch. with Na^COg.
Instantly reduced. Coats the Ch. upon
further blowing.
In ignition tube with Na2CO3 and Ch.
Reduced to the metal.
In flame on platinum wire. Tinges
flame blue.
With borax bead on platinum wire.
30 BLOWPIPE ANALYSIS
In O. F. dissolves easily, forming a limpid
glass.
With Co(N03)2
11. Manganese, Mn203. — Before the Bp.
on Ch. At high temperature turns red.
Before the Bp. on Ch. with Na2CO3. Is
not reduced.
Before the Bp. in O. F. on platinum foil
with -NagCOg. Transparent green mass
when hot. Opaque, bluish-green when cold.
In ignition tube with Na2CO3 and Ch.
Not reduced.
In flame on platinum wire
With borax bead on platinum wire. In O. F.
violet-red while hot, amethyst-red when cold.
With Co(N03)2
12. Mercury, HgO. — Before the Bp. on
Ch. Instantly reduced. Very volatile.
Before the Bp. on Ch. with Na2CO3. Re-
duced and volatilized.
GENERAL REACTIONS 31
In ignition tube with Na.2CO3 and Ch.
Sublimes condensing in the upper part of
the tube as a metallic ring which is seen
with the lens to consist of minute globules
of mercury.
In flame on platinum wire
With borax bead on platinum wire
WithCo(N03)2__
13. Nickel, NiO. — Before the Bp. on Ch.
In O. F. unchanged. In R. F. reduced to
metal, slightly magnetic.
Before the Bp. on Ch. with Na2CO8.
Easily reduced to the metal.
In ignition tube with Na2CO3 and Ch.
In flame on platinum wire
With borax bead on platinum wire. In O.F.
violet while hot, reddish-brown when cold.
With Co(NO3)2._
32 BLOWPIPE ANALYSIS
14. Silver, AgO. — Before the Bp. on Ch.
Easily reduced to the metal. White, mal-
leable, hard bead. Coats the coal dark red
near assay.
Before the Bp. on Ch. with Na2CO3. In-
stantly reduced to metallic globule.
In ignition tube with Na2CO3 and Ch.
Reduced to the metal.
In flame on platinum wire
With borax bead on platinum wire. In
O. F. partially dissolved. Bead becomes
milk-white.
With Co(NO3)2
15. Tin, Sn02. — Before the Bp. on Ch.
Coats the coal yellow while hot, dirty
white when cool. Not reduced.
Before the Bp. on Ch. with Na2CO3. Re-
duced to metallic tin. White, hard, mal-
leable bead. Coating white and close to
assay.
GENERAL REACTION'S 33
In ignition tube with Na2CO8 and Ch.
In flame on platinum wire
With borax bead on platinum wire. In
O. F. small quantity dissolves to limpid
glass.
With Co(NO3)2. Greenish-blue color.
1 6. Zinc, ZnO. — Before the Bp. on Ch.
Upon ignition becomes yellow. Is not
reduced.
Before the Bp. on Ch. with Na2CO3. Re-
duced to metal. Rapidly volatilized, coating
the coal white.
In ignition tube with Na2CO3 and Ch.
In flame on platinum wire
With borax bead on platinum wire. In
O.F. yellow while hot, limpid glass when
cold.
*
With Co(NO3)2. Green mass.
34 BLOWPIPE ANALYSIS
Having now given the principal reactions
for the most important metals, we will pro-
ceed to the examination of the alkali metals,
the alkaline earths, and some of the acid
elements.
THE ALKALI METALS
17. Ammonium, NH4. — This hypotheti-
cal compound is commonly classed among
the alkali metals from its close resemblance
to the members of this group.
To detect the presence of this hypotheti-
cal metal, mix the assay with about four
parts of Na2CO3, place in an ignition tube,
and apply heat. The odor of the evolved
gas will be recognized, and if a piece of
red litmus paper be moistened and held at
the mouth of the tube, it will be turned
blue by the escaping ammonia gas.
We are not authorized to infer the pre-
existence of ammonium, however, from the
GENERAL REACTIONS 3$
appearance of this reaction, for the pres-
ence of nitrogenous organic matter in the
substance, which would be decomposed by
this treatment, would give rise to such a
reaction.
1 8. Potassium. — Potassium is recognized
by the color which its salts impart to the
Bunsen flame. If a portion of a salt of
potassium be held on a platinum wire in
the flame, it imparts a blue-violet tint
which rapidly disappears.
19. Sodium. — Like potassium, this alkali
metal is detected by the color which its
salts give to the flame.
If a sodium salt be held on the platinum
wire in the flame, it imparts an intense
yellow color.
The extreme delicacy of this reaction
has been mentioned elsewhere. The value
36 BLOWPIPE ANALYSIS
of this test is really lessened by its great
delicacy, for it is possible to detect minute
quantities of sodium in almost all sub-
stances, although it may not be in chemi-
cal combination. As an example, draw the
platinum wire between the fingers, and
then place in flame, and note presence of
sodium.
20. Lithium, Li20. — In the Bunsen flame
on the platinum wire it imparts a carmine-
red tinge.
Hydrochloric acid on the sample aug-
ments the coloration.
THE ALKALINE EARTHS
21. Barium, BaO. — In the Bunsen flame
on the platinum wire it imparts an apple-
green coloration. This reaction is intensi-
fied by moistening the sample with hydro-
chloric acid.
GENERAL REACTIONS 37
22. Calcium, CaO. — In the Bunsen flame
on the platinum wire it imparts an orange-
red color, which appears gray when seen
through blue glass.
Hydrochloric acid on the sample makes
the color more intense.
23. Strontium, SrO. — In the Bunsen
flame on the platinum wire it imparts an
intensely red color, which is increased by
converting the substance into the chloride.
THE ACID ELEMENTS
24. Borates. — If the substance be finely
powdered, moistened with glycerine, and
then placed on a platinum wire in the
Bunsen flame, it imparts a brilliant green
color.
If turmeric paper be dipped into a solu-
tion of a borate, and then be dried at
1 00° C., it is turned to a peculiar red
38 BLOWPIPE ANALYSIS
color. These two reactions are extremely
delicate.
25. Bromides. — Bromides treated with
microcosmic salt and oxide of copper on
platinum wire impart to the flame a greenish-
blue color, the edges being decidedly green.
26. Chlorides. — Chlorides are treated in
the same way as bromides. The color
imparted to the flame is azure-blue.
To discriminate between bromides and
chlorides more clearly, the substance is
mixed with anhydrous potassium bisulphate
and fused in an ignition tube.
Bromine and sulphur dioxide are evolved
(if the substance be a bromide), the tube
being filled with a yellow gas possessing
the characteristic odor of bromine.
27. Fluorides. — A small portion of the
substance in a finely powdered condition is
GENERAL REACTIONS 39
placed in one of the ignition tubes, a strip
of moist Brazil-wood paper is introduced
into the open end, and heat is applied.
Hydrofluoric acid is evolved, and the red
color of the paper is changed into a straw-
yellow.
Mica, containing only 0.75% of fluorine,
shows the reaction clearly.
28. Iodides. — Iodides are treated, as the
bromides and chlorides, in a bead of micro-
cosmic salt with oxide of copper. The
flame is colored green.
Fused with potassium bisulphate in an
ignition tube the violet vapors of iodine
are evolved, and thus iodides may be dis-
tinguished from chlorides and bromides.
29. Nitrates. — If a nitrate be heated
upon charcoal before the Bp., violent defla-
gration occurs. If the substance contain-
40 BLOWPIPE ANALYSIS
ing the nitric acid be mixed with a very
small quantity of finely powdered potas-
sium cyanide, the deflagration is accom-
panied with ignition and detonation.
If the substance be mixed in a dry
condition with dry potassium bisulphate,
and is then heated in an ignition tube,
red-brown nitrous fumes are evolved. This
reaction takes place if there is but a small
quantity of nitrate present.
30. Phosphates. — Phosphates impart to
the flame a bluish green color. The color
is made more intense by moistening the
substance with sulphuric acid, and then
taking the paste so formed on the plati-
num wire and placing it in the Bunsen
flame.
31. Silicates. — Silicates, when treated
with microcosmic salt on a platinum wire,
GENERAL REACTIONS 41
suffer decomposition; the bases unite with
the phosphoric acid to form a transparent
glass in which the silica may be seen float-
ing as a cloudy mass.
The bead must only be examined for
silica while hot, since on cooling it becomes
opaque.
32. Sulphides. — Many sulphides, when
heated in an ignition tube, volatilize and
give a sublimate of sulphur in combina-
tion with the metallic portion of the sub-
stance.
A very delicate test for sulphur in what-
ever combination it may be found in a sub-
stance, and which may be performed with
great ease, is to mix the finely powdered
assay with four parts, Na2CO3, and fuse in
an ignition tube. When thoroughly fused
the tube is broken, and the fused mass is
placed on a bright silver coin, and a drop
42 BLOWPIPE ANALYSIS
of water is added. If the substance con-
tains sulphur, a black spot will be observed
on the coin where the fused mass was
placed.
Before going on to the next chapter, the
student should assure himself of his famil-
iarity with the reactions just given, and he
should practise with various substances, the
nature of which is unknown to him.
CHAPTER IV
BEHAVIOR OF SOME OF THE PRINCIPAL ORES
BEFORE THE BLOWPIPE
FOR the sake of practice, and as a fitting
introduction to " Determinative Mineralogy,"
this chapter is appended. It is not intended
to give a detailed account of the minerals,
but rather to set before the student the
most marked characters, such as hardness,
specific gravity, color, lustre, etc.
To determine the hardness of a mineral,
we try to scratch it with the minerals
forming an arbitrary "scale of hardness,"
proceeding successively from the softest to
the hardest. When we say that a certain
mineral has hardness = 4, we mean that the
mineral is scratched by 4 on the scale, and
43
44 BLOWPIPE ANALYSIS
that 4 on the scale is scratched by the
mineral. The scale of hardness chiefly in
use is the Mohs-Breithaupt scale, which is
as follows: —
1. Talc, common laminated light green
variety.
2. Gypsum, crystallized.
3. Calcareous spar, transparent variety.
4. Fluor spar, crystalline.
5. Apatite, transparent.
6. Orthoclase, white cleavable variety.
7. Quartz, transparent.
8. Topaz, transparent.
9. Sapphire, cleavable variety.
10. Diamond.
It seldom happens in determining the
hardness of a mineral that its hardness ex-
actly conforms to that of some one member
of the scale. In such cases we generally
estimate the hardness. For example, sup-
PRINCIPAL ORES BEFORE THE BLOWPIPE 45
pose a mineral was harder than 4, but
softer than 5, and that it was nearer 5
than 4, then we would call its hardness 4^.
In order to preserve the scale some
operators use a three-cornered file, first
cutting the mineral and then the scale
until a number is found, which is abraded
to about the same depth as the mineral
under examination.
Since a set of minerals forming a scale
of hardness is not always at hand, the
following scale given by Chapman is
appended : —
1. Yields easily to the nail.
2. Yields with difficulty to the nail or
just receives an impression from it. Does
not scratch a copper coin.
3. Scratches a copper coin but is also
scratched by it, being of about the same
degree of hardness.
46 BLOWPIPE ANALYSIS
4. Not scratched by a copper coin. Does
not scratch glass.
5. Scratches glass with difficulty, leaving
its powder on it. Yields readily to the knife.
6. Scratches glass easily. Yields with
difficulty to the knife.
7. Does not yield to the knife. Yields
to the edge of a file, though with difficulty.
8. 9, 10. Harder than flint.
Specific gravity cannot well be deter-
mined without the aid of a balance, and
hence its value here is not great.
As in the preceding chapter, alphabetic
arrangement will be employed.
ORES OF ANTIMONY
Stibnite, Sb2S3, Sb.;i, S.29. — *H = 2,
0 = 4.52—4.62. Of lead-gray color and
metallic lustre. Consists of a large number
* H = Hardness, G = Specific Gravity.
PRINCIPAL ORES BEFORE THE BLOWPIPE 47
of needle-shaped crystals. Brittle. Fuses
in candle flame. In an ignition tube yields
a sublimate of sulphur. On Ch. before the
Bp. it is volatilized, giving antimony coating
and tinges the flame pale blue.
ORES OF ARSENIC
Native Arsenic, As. — This contains traces
of Sb, Ag, Fe, Co, and Ni.
H = 3-5> 0 = 5.7-5.8. Dark gray in
color. Fracture tin-white, tarnishing rap-
idly. Volatilizes before the Bp. on Ch.
without melting, giving white coating of
arsenious acid and characteristic garlic odor.
In ignition tube it sublimes, giving arsenical
ring.
Realgar, AsS, As . 70, S . 30. — H = 1.5 — 2,
0 = 3.56. Bright red to orange-red color
and resinous lustre. In an ignition tube
it fuses and finally sublimes. The sub-
48 BLOWPIPE ANALYSIS
limate when cool is red and transparent.
Fuses readily before the Bp. on Ch. and
burns with - pale yellowish flame, emitting
gray-white fumes having garlic odor.
Orpiment, As2S3, As . 61, S . 39. —
H = 1.5 -2.0, 0=3.4-3.5.
Lemon-yellow in color and resinous or
pearly lustre. Sectile. Before the Bp. on
Ch. behaves like realgar, but in an ignition
tube it gives a dark yellow sublimate which
is transparent.
ORES OF BISMUTH
Native Bismuth, Bi. — This contains traces
of As, Te, and S.
H = 2.0 - 2.5, G = 9.7 - 9.83. Color, silver-
white, slightly tinged with red. Metallic
lustre. Brittle when cold, but may be lami-
nated when hot. Before the Bp. on Ch.
behaves like pure Bi.
PRINCIPAL ORES BEFORE THE BLOWPIPE 49
Bismuthite, Bi2O3 . 90, CO2 . 7, H2O . 3, —
H = 4.0 -4.5, 0 = 6.9-7.8.
Usually of a white or light greenish color
and vitreous lustre, in acicular crystalliza-
tions. In an ignition tube decrepitates,
yielding water and turning gray. Before
the Bp. on Ch. it fuses easily and is reduced
to metallic globule, coating the Ch. with
Bi2O3. With Na2CO3 it occasionally gives
the sulphur reaction.
ORES OF CHROMIUM
Chromic Iron Ore, FeO.32, Cr2O8.68. —
A12O3, Fe2O3, MnO, and MgO are commonly
present. H = 5.5, 0 = 4.32-4.57. Occurs
usually massive. Color, iron-black to brown-
ish black. In many varieties strongly mag-
netic. Lustre, shining and somewhat me-
tallic. Heated in an ignition tube, remains
unchanged. Infusible before the Bp. on Ch.
50 BLOWPIPE ANALYSIS
Before the Bp. on Ch. with Na2CO3 and
KCN yields metallic iron. In borax bead
it slowly dissolves to a clear transparent
glass, which is a beautiful green when cool.
ORES OF COBALT
Smaltite, Co(Fe, Ni) As2, Co . 28, As . 72.
— H = 5.5, G = 6.37 - 7.30. Color, tin-white
or steel-gray. Lustre, metallic. When
heated to redness in an ignition tube it
yields a sublimate of metallic arsenic. Before
the Bp. on Ch. it fuses readily, with emis-
sion of arsenical fumes, to a grayish black
magnetic globule. This globule may be
examined for iron, cobalt, and nickel with
the borax bead.
Cobaltite, CoS2 + Co As2, Co. 36, As. 45,
8.19. — H = 5.5, 0 = 6.0-6.3. Color, silver-
white tinged with red. Metallic lustre.
Before the Bp. on Ch. fuses easily, with
PRINCIPAL ORES BEFORE THE BLOWPIPE 5 1
emission of copious arsenical fumes, to a
gray magnetic globule. Remains unchanged
in the ignition tube.
Linnaeite, (Co, Ni)3S4, (Co, Ni)s8, 8.42.—
H = 5«5, 0 = 4.8-5.0. Color, bright steel-
gray, sometimes reddish. Lustre, metallic.
Crystallizes in the regular octahedron.
Before the Bp. on Ch. fuses to a metallic
globule which is attracted by the magnet.
With borax bead gives reaction for cobalt.
Erythrite, Co3O8As2 + 8 H2O,
CoO.37.6, H2O.24.o.—
H= 1.5 -2.0, 0=2.95.
Color, crimson to peach-red. When crys-
tallized, of pearly lustre, but frequently dull
and earthy. Heated in ignition tube gives
off water, and color changes to blue or
green. Before the Bp. on Ch. in R. F. it
52 BLOWPIPE ANALYSIS
emits arsenical fumes and melts to a dark
gray globule which with the borax bead
reacts for cobalt.
ORES OF COPPER
Native Copper, Cu. —
H = 2.5-3, 0 = 8.5-8.9.
Color, copper-red. Lustre, metallic. Oc-
curs usually massive and very arborescent.
Before the Bp. on Ch. it fuses, and if
the heat is sufficiently high it assumes a
bright bluish-green surface ; on cooling it
is covered with a coat of black oxide. In
the borax bead it reacts for copper.
Chalcopyrite, CuFeS2, Cu . 35, Fe . 30,
8.35.— H = 3.5 -4, 0 = 4.1-4.3. Color,
brass-yellow, often golden-yellow. Lustre,
metallic. Occurs crystallized, but is gener-
ally found massive. Is easily scratched
PRINCIPAL ORES BEFORE THE BLOWPIPE 53
with a knife. Heated in an ignition tube
decrepitates, and occasionally yields a faint
sublimate of sulphur. Before the Bp. on
Ch. it blackens, but becomes red again on
cooling. Before the Bp. on Ch. with Na2CO3
and KCN it is reduced, and the metals are
obtained in separate masses. It reacts with
the borax bead for copper and iron.
Copper Glance, Cu2S, Cu .80, S . 20. —
H = 2.5 - 3.0, G = 5.5 - 5.8. Color, dark
blue to steel-gray. Occurs in compact
masses, often very shining. Before the Bp.
on Ch. fuses to a globule which boils
and emits glowing drops. Sulphur dioxide
escapes abundantly, and the outer flame is
colored blue. Before the Bp. on Ch. with
Na2CO3 yielding a metallic globule.
Tetrahedrite, 4 CuS + Sb2S3. — Frequently
contains silver, iron, mercury, and zinc.
54 BLOWPIPE ANALYSIS
H = 3.0 -4.0, 0 = 4.5-5. Color, steel-gray
to iron-black. Heated in an ignition tube
fuses and gives a sublimate of antimonious
oxide. When mercury is present this con-
denses in the upper part of the tube, form-
ing the characteristic mirror. Before the
Bp. on Ch. it fuses readily to a metallic
globule, emitting dense white fumes ; zinc
and antimony coatings are deposited on the
Ch. After long ignition before the Bp., if
the mineral is finely powdered and mixed
with Na2CO3 and KCN, the ore is reduced
to the metal.
Cuprite, Cu2O, Cu . 89, 0 . 1 1. —
H = 3.5 -4.0, 0 = 5.5-6.15.
Color, intense crimson-red. Before the Bp.
on Ch. blackens and fuses quietly, and finally
yields a metallic globule of copper. Before
the Bp. on Ch. with Na2CO3 and KCN it
is easily reduced.
PRINCIPAL ORES BEFORE THE BLOWPIPE 55
Malachite, 2 CuO + CO2+ H2O, CuO . 72,
CO2.20, H2O.8.—
H = 3.5 -4.0, 0=3.90-4.03.
Color, bright green. Occurs generally in
mammillated concretions. Lustre, shining
and fracture, silky. Heated in an ignition
tube yields water and blackens. Before the
Bp. on Ch. it fuses to a metallic globule.
Before the Bp. on Ch. with Na2CO3 and
KCN it is easily reduced. With borax
bead gives characteristic coloration.
Azurite, 3 CuO + 2 CO2+ H2O, CuO . 69,
C02.26, H20.5.—
H = 3.5 -4.0, 0=3.77-3.83.
Color, azure-blue. Occurs usually in crys-
tallized or globular masses. Lustre, earthy
or vitreous. Before the Bp. and with other
reagents behaves like malachite.
56 BLOWPIPE ANALYSIS
Chrysocolla CuO + SiO2 + 2 H2O,
CuO.45.3, H2O.20.5. — H = 2.0- 3.0, G=2.
Color, bluish-green, closely resembling mala-
chite. Occurs usually as an incrustation,
its surface being very smooth, like enamel.
In an ignition tube it blackens and yields
water. Before the Bp. on Ch. in O. F. it
blackens, coloring the flame bright green;
in the R. F. it turns red. Before the Bp.
on Ch. with Na-jCO3 yields metallic copper.
In borax bead it reacts for copper.
Atacamite, CuCl2 + 3 CuO2H2 - Cl . 16.6,
0 . 20.3, Cu . 50. i , H2O . 1 3.0. —
H = 3.0 -3.5, G= 3.75 -3.77.
Color, green to blackish green. Lustre,
adamantine to vitreous. In an ignition
tube yields water. Before the Bp. on Ch.
colors flame blue. Before the Bp. on Ch.
with Na2CO3 and KCN is reduced to the
metal. In borax bead it reacts for copper.
PRINCIPAL ORES BEFORE THE BLOWPIPE S7
ORES OF IRON
Limonite, 2 Fe2O3 + 3 H2O, Fe2O8 . 86,
H2O . 14. — H = 5.0-5.5, G = 3.6 - 4.0.
Color, brown to ochre-yellow. Earthy or
semi-metallic in appearance. In an igni-
tion tube yields water. Before the Bp.
on Ch. infusible. In borax bead reacts for
iron.
Hematite, Fe,O3, Fe . 70, 0 . 30. —
H = 5-5 -6-5, 0 = 4.9-5.3.
Color, dark steel-gray to iron-black. Lustre,
metallic. When pulverized yields a red
powder. Before the Bp. on Ch. infusible.
After long roasting becomes magnetic. In
borax bead gives usual indications of iron.
Magnetite, Fe3O4, FeO .31, Fe2O3 . 69. —
H = 5-5 -6.5, 0=5.17-5.18.
58 BLOWPIPE ANALYSIS
Color, iron-black. Lustre, shining and me-
tallic. Pulverized, its powder is black. It
is strongly magnetic. Fuses with difficulty
before the Bp. on Ch. In borax bead reacts
for iron.
Pyrites, FeS2, Fe . 47, S . 53.—
H = 6.0 - 6.5, G = 4.95 - 5.20.
Color, brass-yellow. Lustre, metallic. Oc-
curs commonly in cubes. It often con-
tains small quantities of Au, Ag, Cu, As,
Co, and Mn. Heated in an ignition tube
gives a sublimate of sulphur, the residue
becoming magnetic. Before the Bp. on
Ch. in O. F. sulphur is burned off and
the red oxide remains. This residue may
then be examined for iron, etc.
Marcasite (White Iron Pyrites). — Having
the same general composition as pyrite, but
much lighter in color. Crystals, prismatic.
Before the Bp. on Ch. behaves like pyrite.
PRINCIPAL ORES BEFORE THE BLOWPIPE 59
Pyrrhotite, Fe7S8, Fe.6o.5, 8.39.5.—
H = 3.5 -4.5, 0 = 4.58-4.64.
Color, bronze-yellow. Closely resembles
pyrite, but may be distinguished from it
by being feebly magnetic. Heated in an
ignition tube yields no sublimate. Before
the Bp. on Ch. fuses to a magnetic globule,
which exhibits a yellowish crystalline struc-
ture when fractured.
Mispickel, FeAsS, Fe.34, As. 46, 8.20. —
H = 5.5~6.o, G = 6.0 -6.2. Color, silver-
white. Lustre, metallic; very brittle. Often
associated with it we find small quantities
of Co, Ag, and Au. Heated in an igni-
tion tube it first yields a red sublimate of
sulphide of arsenic, and then afterward
a crystalline sublimate of metallic arsenic.
Before the Bp. on Ch. emits dense fumes
of arsenic and deposits a coating on the
60 BLOWPIPE ANALYSIS
coal; it then fuses to a globule which
behaves like pyrrhotite.
Siderite, FeCO3, FeO.62, CO2.38.—
H = 3.5 -4.5, 0=3.7-3.9. Color, grayish
yellow to reddish brown. Lustre, pearly.
Crystallizes in rhombohedrons with curved
faces ; these crystals are distinctly cleavable
and massive. Heated in an ignition tube
it decrepitates with evolution of carbon
dioxide. Before the Bp. on Ch. infusible.
Before the Bp. on Ch. with Na2CO3 it fuses
to a magnetic mass. With borax bead it re-
acts for iron and sometimes for manganese.
ORES OF LEAD
Galena, PbS, Pb . 87, S . 1 3. —
H = 2.5, 0=7.4-7.6.
Color, bluish gray, slowly tarnishing. Lus-
tre, metallic. Crystals in the form of cubes.
PRINCIPAL ORES BEFORE THE BLOWPIPE 6 1
Heated in an ignition tube it sometimes
decrepitates and yields a sublimate of sul-
phur. Before the Bp. on Ch. easily reduced
to the metallic state, the Ch. becoming
coated with sulphate and oxide of lead.
The metallic globule usually contains a
little silver. To separate this, the process
known as "cupellation" is employed. A hole
is bored into the Ch. about i cm. in diame-
ter and about 6 mm. deep. Into this hole
is placed a stiff paste made by mixing finely
pulverized bone-ash with a little soda and
water. This paste is pressed in hard, and
then the surface is smoothed off, and the
centre is slightly depressed with the rounded
end of a glass rod. The charcoal so pre-
pared is set in a warm place to allow the
paste to dry. When the paste is quite
dry the small globule of lead is placed in
the depression in the centre of the bone-
ash "cupel," and is there exposed to the
62 BLOWPIPE ANALYSIS
O. F. from the Bp. The lead is oxidized
and is absorbed by the bone-ash, while any
silver present will remain in the central
depression as a bright shining bead.
Cerusite, PbCO3, PbO . 84, CO2.i6.—
H = 3.0 -3.5, 0 = 6.46-6.57. Color, white,
gray, or yellow. Lustre, adamantine. Crys-
tallizes in prismatic needles When heated
in an ignition tube carbon dioxide is evolved
and the residue turns yellow. Before the
Bp. on Ch. readily reduced to metallic
lead.
Anglesite, PbSO4, PbO . 74, SO3.26.—
H = 2.0—3.0, 0 = 6.12 — 6.39. Color, yel-
low, gray, and brown. Lustre, adamantine,
resinous. Heated in an ignition tube
decrepitates, and sometimes yields a little
water. Before the Bp. on Ch. fuses to
a clear bead, which on cooling becomes
PRINCIPAL ORES BEFORE THE BLOWPIPE 63
opaque. Before the Bp. on Ch. with
Na2CO3 is reduced to the metal giving a
yellow coating. The Na^Og absorbed by
the coal reacts for S.
ORES OF MANGANESE
Pyrolusite, MnO2, Mn . 63.2, O . 36.8. —
H = 2.0—2.5, 0 = 4.82. Color, iron-black to
steel-gray. Lustre, non-metallic. Heated
in an ignition tube yields generally a little
water, and if the temperature be high
enough, oxygen is evolved. Before the
Bp. on Ch. infusible. In borax bead gives
characteristic color.
Psilomelane, Mn2O8 + H2O. —
H = 5.5 -6.0, 0=3.7-4.7.
Color, iron-black to steel-gray. Generally
resembles pyrolusite, but is distinguished
from it by its superior hardness. It fre-
64 BLOWPIPE ANALYSIS
quently contains BaO and Li2O. It behaves
before the Bp. like pyrolusite.
Wad (Bog Manganese). — This mineral is
essentially MnO2, MnO, and H2O, with
small quantities of Fe2O3, A12O3, BaO, SiO2,
etc., associated with it.
H = 0.5 -6.0, 0 = 3.0-4.2. Color, dull
black. Heated in an ignition tube yields
water in abundance, otherwise it behaves
like pyrolusite.
ORES OF MERCURY
Native Mercury, Hg. — G = 13.5 — 13.6.
Color, silver-white. Is liquid at all ordi-
nary temperatures. Heated in an ignition
tube is volatilized, the vapors condensing
in the upper end of tube to small metallic
globules of Hg. Before the Bp. on Ch. it
is volatilized. Frequently contains Ag.
PRINCIPAL ORES BEFORE THE BLOWPIPE 65
Cinnabar, HgS2, Hg.86, S. 14. —
H = 2.0 -2.5, G = 8.0 -8.2.
Color, scarlet-red to brick-red. Lustre, non-
metallic. When pulverized yields a powder
of vermilion-red color. Heated in an ig-
nition tube it volatilizes, yielding a black
sublimate, which by friction becomes red.
Before the Bp. on Ch. it is wholly vola-
tilized. Heated in an ignition tube with
Na2CO3 metallic mercury sublimes, con-
densing in the upper portion of the tube
in minute globules.
ORES OF NICKEL
Millerite, NiS, Ni.644, $.35.6.—
H = 3.0 -3.5, 0=5.2-5.6.
Color, brass-yellow. Brittle. Before the
Bp. on Ch. it fuses to a magnetic, metallic
globule. The roasted mineral gives in the
borax bead the color reaction characteristic
66 BLOWPIPE ANALYSIS
of nickel, and sometimes that of cobalt,
which is often associated with it.
Niccolite, NiAs, Ni . 44, As . 56. —
H = 5.0 -5.5, G= 7.35 -7.67.
Color, pale copper-red. Lustre, metallic.
Very brittle. Heated in an ignition tube
yields a copious sublimate of arsenious
oxide, the residue falling to a greenish
powder. Before the Bp. on Ch. fuses to a
white brittle globule emitting arsenical
fumes. In borax bead gives color character-
istic of nickel. Frequently in this mineral
a portion of the arsenic is replaced by
antimony.
ORES OF SILVER
Native Silver, Ag. —
H = 2.5 — 3.0, G=IO.I — n.o.
Color, silver-white. Lustre, metallic. Duc-
tile and malleable. Usually occurs asso-
PRINCIPAL ORES BEFORE THE BLOWPIPE 6/
ciated with Au, As, Sb, Cu, Fe, etc.
Before the Bp. on Ch. easily fuses to a
globule which is surrounded with a dark
red coating on the coal.
^
Argentite, Ag.2S, Ag.S/.i, S. 12.9. —
H = 2.0 — 2.5, 0=7.20-7.36.
Color, blackish lead-gray. Lustre, metallic.
Very sectile. Before the Bp. on Ch. in
O. F. intumesces with evolution of sulphur
dioxide, finally yielding a metallic globule
of Ag.
Pyrargyrite, Ag3SbS3, Ag.59.8, Sb.22.5,
8.17.7.— H = 2.5, 0=5.77-5.86. Color,
black to dark cochineal-red. Lustre, metal-
lic, adamantine. In an ignition tube it
yields on continued heating a sublimate of
antimony sulphide. Before the Bp. on Ch.
it gives a coating of antimony trioxide.
68 BLOWPIPE ANALYSIS
Before the Bp. on Ch. with Na2CO3 is
reduced to metallic silver.
Proustite, Ag3S3As, Ag.65.5, As. 15.1,
S. 194.— H = 2.0 -2.5, 0=5.57-5.64.
Color, light red. Lustre, splendent, adaman-
tine. Before the Bp. on Ch. it behaves like
pyrargyrite, save that it gives off arsenical
fumes instead of antimonious oxide.
Stephanite, Ag5S4Sb, Ag.68.5, Sb.is.3,
S . 16.2. — H = 2.0 — 2.5, G = 6.2 — 6.3. Color,
iron-black to blackish gray. Lustre, me-
tallic. Very brittle and fragile. In an ig-
nition tube it decrepitates, fuses, and finally
yields a slight sublimate of antimony tri-
sulphide. Before the Bp. on Ch. gives a
coating of antimonious oxide. Before the
Bp. on Ch. with Na2CO3 a globule of
metallic silver is obtained. The mineral
frequently contains copper and iron.
PRINCIPAL ORES BEFORE THE BLOWPIPE 69
Kerargyrite, AgCl, Ag.75«3, 0.24.7.—
H =1.0—1.5, 0=5.52. Color, white, gray,
yellowish, greenish to blue. Lustre, resin-
ous, adamantine. Soft like wax. Fuses
easily in a candle-flame. Before the Bp.
on Ch. it is readily reduced to metallic
silver.
ORES OF TIN
Cassiterite, SnO2, Sn.79, O.2i. —
H = 6.0 -7.0, 0 = 6.8-7.0.
Color, brown, black. Lustre, adamantine,
brilliant. Occurs crystallized in square
prisms. Reentrant angles characteristic.
Before the Bp. on Ch. with Na2CO3 and
KCN reduced to a metallic globule of tin.
In the borax bead gives characteristic re-
action.
Stannite, 2 Cu2S . SnS2 + 2 (FeS . ZnS)
Sn . S2. — H = 4.0, G = 4.3 — 4.5. Color,
70 BLOWPIPE ANALYSIS
steel-gray to iron-black. Lustre, metallic.
Occurs usually massive and disseminated.
Heated in an ignition tube it yields sul-
phur dioxide. Before the Bp. on Ch. it
emits sulphur dioxide and becomes cov-
ered with oxide of tin. Before the Bp. on
Ch. with Na2CO3 and KCN it gives an
impure globule of copper. A very difficult
mineral to determine.
ORES OF ZINC
Calamine, H2Zn2O5Si, SiO2.25.o, ZnO.
67.5, H2O.7.5.— H = 4.5 -5.0, 0=34-3.5.
Color, white, gray, bluish, or brown. Lustre,
vitreous. Brittle. In an ignition tube
yields water when heated and becomes
milky white. Before the Bp. on Ch. prac-
tically infusible. With Co(NO3)2 it assumes
a green color which passes into a fine blue
when the heat is increased.
PRINCIPAL ORES BEFORE THE BLOWPIPE 71
Smithsonite,
Zn . CO3, ZnO . 64.8, CO2 . 35.2. —
H = 5, 0 = 4.30-445. Color, gray, yellow,
brown, and green. Lustre, vitreous, pearly.
Heated in an ignition tube CO2 is evolved,
residue appearing white. It often contains
impurities of Cd, Pb, Fe, Mn, Ca, and Mg.
When these are present the residue in the
ignition tube becomes dark on cooling.
Before the Bp. on Ch. with Na2CO3 and
exposed to the R. F. it is decomposed. It
gives the characteristic reaction for zinc
with Co(NO3)2.
Zincite, ZnO, Zn . 80.3, 0 . 19.7. —
H = 4.0 -4.5, 0 = 5.43-5.70.
Color, blood-red. Lustre, brilliant, sub-
adamantine. Before the Bp. on Ch. infusible.
Before the Bp. on Ch. with Na2CO3 gives
coating of zinc oxide. Oives characteristic
72 BLOWPIPE ANALYSIS
reaction with Co(NO3)2. It frequently con-
tains a small quantity of Mn2O3, which may
be detected in the borax bead.
Sphalerite, ZnS, Zn . 67, S . 33. —
H = 3-5-4-0, 0=3.9-4.1.
Color, yellow to black. Lustre, resinous, brill-
iant, and sometimes submetallic. Heated
in an ignition tube sometimes decrepitates.
Before the Bp. on Ch. infusible. Before the
Bp. on Ch. with Na2CO3 easily reduced.
With Co(NO8)2 gives the characteristic re-
action. It frequently contains small quan-
tities of Cd, Hg, Sn, Pb, Au, Ag, etc.
PRINCIPAL ORES BEFORE THE BLOWPIPE 73
TABLE OF COLORS OF COATINGS ON CHARCOAL
ELEMENT
COLOR HOT
COLOR COLD
Antimony
Arsenic
Bismuth
Cadmium
(Rather volatile)
(Very volatile)
Orange-Yellow
Brownish Yellow
White
White
Lemon-Yellow
Reddish Brown
Lead
Silver
Lemon- Yellow (volatile)
Dark Red
Lemon-Yellow
Dark Red
Tin
Faint Yellow
White
Zinc
Yellow
White
II
TABLE OF FLAME COLORATIONS
RED
YELLOW
GREEN
Calcium
Sodium
Barium
Lithium
Boron
Strontium
Iodine
BLUISH GREEN
BLUE
VIOLET
Bromine
Chlorine
Potassium
Copper
Phosphorus
74
BLOWPIPE ANALYSIS
III
TABLE OF COLORS OF BORAX BEADS IN OXIDIZING FLAME
ELEMENT
COLOR HOT
COLOR COLD
Aluminum
Colorless to Cloudy
Colorless to Cloudy
Antimony
Yellowish
Colorless
Barium
Colorless to Opaque
Colorless to Opaque
Bismuth
Yellow
Colorless
Cadmium
Yellow
Colorless to White
Calcium
Colorless
Colorless
Chromium
Reddish Yellow
Yellowish Green
Cobalt
Blue
Blue
Copper
Green
Greenish Blue
Iron
Orange
Yellow
Lead
Yellow
Colorless
Magnesium
Colorless
Colorless
Manganese
Violet
Reddish Violet
Nickel
Violet
Reddish Brown
Silver
Colorless
Milk-White
Strontium
Colorless to Opaque
Colorless to Opaque
Tin
Colorless
Colorless
Zinc
Yellowish
Colorless
PRINCIPAL ORES BEFORE THE BLOWPIPE ?$
IV
TABLE OF COLORS OF BORAX BEADS IN REDUCING FLAME
ELEMENT
COLOR HOT
COLOR COLD
Aluminum
Colorless
Colorless
Antimony
Colorless
Cloudy
Barium
Colorless
Colorless
Bismuth
Colorless
Gray — Cloudy
Cadmium
Colorless
Gray — Cloudy
Calcium
Colorless
Colorless
Chromium
Green
Green
Cobalt
Blue
Blue
Copper
Colorless
Red
Iron
Yellowish Green
Yellowish Green
Lead
Colorless
Gray
Magnesium
Colorless
Colorless
Manganese
Colorless
Pink
Nickel
Colorless
Gray — Cloudy
Silver
Colorless
Gray
Strontium
Colorless
Colorless
Tin
Colorless
Colorless
Zinc
Colorless
Gray
BLOWPIPE ANALYSIS
TABLE OF COLORS OF MICROCOSMIC SALT BEADS IN
OXIDIZING FLAME
ELEMENT
COLOR HOT
COLOR COLD
Aluminum
Colorless
Colorless
Antimony
Yellowish
Colorless
Barium
Colorless to Opaque
Colorless to Opaque
Bismuth
Yellow
Colorless
Cadmium
Yellowish
Colorless
Calcium
Colorless
Colorless to Opaque
Chromium
Reddish
Green
Cobalt
Blue
Blue
Copper
Green
Greenish Blue
Iron
Red
Brownish Red
Lead
Yellowish
Colorless
Magnesium
Colorless
Colorless
Manganese
Brownish Violet
Reddish Violet
Nickel
Reddish
Yellow
Silver
Yellowish
Yellowish
Strontium
Colorless
Colorless
Tin
Colorless
Colorless
Zinc
Yellowish
Colorless
PRINCIPAL ORES BEFORE THE BLOWPIPE 77
VI
TABLE OF COLORS OF MICROCOSMIC SALT BEADS IN
REDUCING FLAME
ELEMENT
COLOR HOT
COLOR COLD
Aluminum
Colorless
Colorless
Antimony
Colorless
Gray — Cloudy
Barium
Colorless
Colorless
Bismuth
Colorless
Gray — Cloudy
Cadmium
Colorless
Gray — Cloudy
Calcium
Colorless
Colorless
Chromium
Reddish
Green
Cobalt
Blue
Blue
Copper
Dark Green
Brownish Red
Iron
Red
Reddish
Lead
Colorless
Gray — Opaque
Magnesium
Colorless
Colorless
Manganese
Colorless
Colorless
Nickel
Colorless
Gray
Silver
Colorless
Gray
Strontium
Colorless
Colorless
Tin
Colorless
Colorless
Zinc
Colorless
Gray — Cloudy
THE PRACTICAL METHODS
OF
ORGANIC CHEMISTRY
AUTHORIZED TRANSLATION
1 2 mo. Cloth. Price, $1.60, net
BY TRANSLATED BY
LUDWIG GATTERMANN, Ph.D., WILLIAM SHAFER, Ph.D.,
Professor in University of Heidelberg. Instructor in Organic Chemistry
in Lehigh University.
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... It is permanently a worker's guide."
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OUTLINES
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Cloth. 8vo. Price, $3.50 net
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