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I
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t
f
WORKS
CAVENDISH SOCIETY.
g FOUNDED 1846.
f
HAND-BOOK
^-^"^."-x
OF
CHEMIST
BY
LEOPOLD GMELIN.
FftOVBBSOB OT CHXXI8TET IN THB UNIVBUTTT 07 BBIDBLBBIO,
AMP XBKBBB Of TABI0U8 LBABXBD SOOZBTZBS IK BEBUH, BONN, CATANIA, DBBIDBN, TBBIBUBO,
PBANKFOBT, OtfniNQBN, HALLS, HAXBVBO, HANAU, HBIDBLBBBQ, JAMT, LONBON,
MABBUBO, MUNICH, FABIS, FBTBBflBVBGH, TBNNA, AND WBTTBBAU.
VOL. IV.
METAL ^ — rcorUinuedJ
TBANSLATEB BT
HENRY WATTS, B.A., F.C.S.
AflSISTANT IN THB BIBKBBCB LABOBATOBT, UNITBBSITT COLLBQB, LONDON.
LONDON:
PRINTED FOR THE CAVENDISH SOCIETY.
MDCCCL.
LONDON :
PBINTBD BT HARRISON AND SON,
ST. martin's LANB.
M^BBmMIUM
CONTENTS OF VOL. IV.
Metals (continued).
Chapter XVII. TANTALUM.
Page
MemoirSy &c. relating to Tantalum
Historj. Sources. Preparation- Properties
Compounds of Taktalum.
Tantalum and Oxygen.
Tantalous Acid.— TaO'
. Tantalic Acid.— TaO»
Hydrate of Tantalic Acid ....
Tantalates
Tantalum and Boron.
Borate of Tantalic Acid
Tantalum and Phosphorus.
Phosphate of Tantalic Add
Tantalum and Sulphur.
Sulphide of Tantalum
Sulphate of Tantalic Acid .... ....
Tantalum and Chlorine.
Terchloride of Tantalum
Tantolate of Terchloride of Tantalum f....
Hydrochlorate of Tantalic Acid .... *
Tantalum and Fluorine.
Fluoride of Tantalum
Basic Hydrofluate of Tantalic Acid
Auid Hydrofluate of Tan talic Acid
Tantalum and Nitrogen.
Tantalate of Ammonia
Fluoride of Tantalum and Ammonium ....
TOL. IT.
2
3
4
6
6
6
7
7
7
8
8
8
8
a
VI
CONTENTS.
Tantalum and Potassium.
Tantalate of Potash ....
Sulphate of Tantalic Add and Potash ....
Fluoride of Tantalum and Potassium
Tantalam and Sodium.
Tantalate of Soda
Fluoride of Tantalum and Sodium
Tantalum and Barinm«
Tantalate of Baryta
Tantalam and Calcium*
Tantalate of Lime
Hjdrofluate of Tantalic Acid and Lime....
Tantalam and Ma^eaiom.
Hjdrofiuate of Tantalic Acid and Magnesia
Tantalam and Yttriam.
Fergtuonite ,... ,„, ,.,.
YttroianiaRte
Eugenite .... „„ „.,
Tantalam and Thorinom.
PyroeMore
Tantalam and Alominam.
Tantalate of Alumina
Other Compoands of Tantalam
#.•*
•«*•
»..•
Page
9
10
10
n
11
II
11
11
12
12
19
14
14
14
14
•««•
% Chaptm XVIL (a). NIOBIUll
MemoirB9.&c. History. Sources. Preparation ....
Jrroperties .... ..., ,.„ ,,.,
GoKPOuxns OT Niobium.
Niobiam and Oxygen.
Niobic Acid
Hydrate of Niohio Add
Niobiates .... .,.
Niobiam and Salphar.
Sulphide of Niobium ....
Sulphate of Niobic Add
Niobiam and Chlorine.
CMoride of Niobium ....
Niobiam and Potassiam.
Niobiate and Carbonate oi Potash
•••■
•M«
• •*.
16
16
•»••
16
17
17
18
18
18
18
•••
i-
CONTBNTSi vii
Niobiam and Sodium.
Niobiate of Soda .... .... .... •••• 19
Niobiam and Yttrium.
Samarskite .... .... .... ».•* 19
f Chaptke XVII. (b.) PBLOPIUM.
Memoirs. History. Somt;es, &c. .... «... .... 20
Compounds of Pelopiuh*
Pelopium and Oxygen.
Pelopic Acid .... .... .... .«•• 20
Hydrate of Pelopic Add ..<. im. m.« 21
Pelopiates.... .... •.- ••,. 22
Pelopium and Sulpbur.
Sulphide of Pelopimn.... ^.
Sulphate of Pelopic Acid ....
Pelopium and Chlorine.
Chloride of Pelopium.... ..« «««• m** 22
Pelopium and Potassium.
Pelopiate of Potash .... .«.• mm 23
Pelopium and Sodium.
Pelopiate of Soda .... .... ••• *ip» 23
CHAPTCtt XVIII. TtWGSTEN.
MemoirSy &c. .... .^i, ....
History. Sources. Preparation.
Properties .... .... .... «•«.
Compounds of Tungsten.
Tungsten and Oxygen.
Tungstoos Oxide. — ^WO* .... .,„ «« 25
Tungstic Oxide.— WO* .... .... .... 25
Tuugstic Acid. — ^WO' .... .... ..« 26
Tungstates .... .... ,^» 29
Tungsten and Phosphorus.
Phosphide of Tungtff en .... .... mm 32
Tungsten and Sulphur.
Sulphides of Tirngsten.
Bisulphide ; Sulphotlttigstotts Add. — W9* >... 32
Tersulphide; Sulphotungstic Add.'^WS* .... 33
a2
MM
24
•t.l
•ffM
24
*ll«
25
VI CONTENTS.
Tantalam and Potftssium.
Tantalate of Potash .... .... ,... •... 9
Sulphate of Tantalic Add and Potaah .... .... 10
Fluoride of Tantalum and Potaasium .... .... 10
Tantalam and Sodium.
Tantalate of Soda .... .... .... 11
Fluoride of Tantalmn and Sodium .... .... 11
Tantalum and Barium,
Tantalate of Baryta .... .... .... 11
Tantalum and Calcium.
Tantalate of Lime .... .... .... .... 11
Hjdrofluate of Tantalic Acid and Lime.... .... 11
Tantalum and Ma^esiom.
Hjdrofloate of Tantalic Acid and Kagneeia .... .... 12
Tantalum and Yttrium.
Fergwmite .... .... .... .... 12
rttrotaniaiite .... .,.. .... .... 12
Ewemte .... .... ,... ..^ 14
Tantalum and Thorinum.
PifroeMwre .... .... ^., ,.^ 14
Tantalum and Aluminum.
Tantalate of Alumina .... .... .... 14
Other Compounds of Tantalum .... .... .... u
f Chaptee XVn. (a). NIOBIUll
Memoiri>&c Hiatory. Souroea. Pi^paiation .... .... 16
Properties .... .... .... .... „^ 10
CoKPouxns OF Niobium.
Niobium and Oxygen.
NiobicAcid .... .... .... ..., 15
Hydrate of NioWc Acid .... .... .... 17
Niobiates .... .... .... .... 17
Niobium and Sulphur.
Sulphide of Niobium.... .... .... .... is
Sulphate of Niobic Acid .... .... .... le
Niobium and Chlorine.
Chloride of Niobium .... .... .... .... is
Niobium and Potaasium.
Niobiate and Carbonate of Potaah .... .... is
CONTBNTSk vii
Page
Niobiam and Sodium.
Niobiate of Soda .... .... .... •••• 19
Niobiam and Yttrium.
Sanuirskiie .... .... .... •«»« 19
f Chaptee XVII. (b.) PBLOPIUM.
Memoirs. History. Sources, &c. .... •«.• .... 20
Compounds of Pelopivm.
Pelopiam and Oxygen.
Pelopic Acid ....
Hydrate of Pelopic Acid
Pelopiates....
Pelopium and Sulpbur.
Sulphide of Pelopium....
Sulphate of Pelopic Acid ....
Pelopium and Chlorine.
Chloride of Pelopium.... ..^ •«•• mm S2
Pelopiam and Potassium.
Pelopiate of Potash .... •«•• nm 23
Pelopiam and Sodium.
Pelopiate of Soda .... .... ... *»*» 23
Chapter XVIII. TtftCGSTBN.
....
•«.•
20
..1*
I«ti
•i-
21
••M
M*«
22
••••
.*(.
•«•
»•«
••••
1
<i.. .44.
«l*i
MM
24
•Mf
MM
24
*h*
25
MemoirSj Sec.
History. Sources. Preparation.
Properties ....
Compounds of Tungsten.
Tungsten and Oxygen.
Tungstous Oxide. — ^WO* .... .„. „« 25
Tungstic Oxide. — ^WO* .... .... •«. 25
Tnngstic Acid. — ^WO* .... .... «« 26
Tungstates •... .... c^. 29
Tungsten and Phospborus.
Phosphide Of Tungsten .... .... m* 32
Tungsten and Sulphur.
Sulphides of Tungsten.
Bisulphide ; Sulphoiffligstotlfl Acid.'"-WS* j... 32
Tersulphide; Sulphotungstic Acid,-^"WS* .... 33
a2
I
YiU CONTENTS.
Page
TnngBtote of Tenolphide of Tungsten .... .... 34
Sulphate of Tungstic Acid! .... .... 34
Tungsten and Bromine.
Oxybromide of Tungsten .... .... •*.. 34
Tungstate of Tungstic Bromide .... .... 34
Tungsten and Chlorine.
Chlorides of Tungsten.
Bichloride ; Tungstous Chloride.— WCl' .... 35
Teichloride; Tungstic Chloride.~WCl' .... 36
Tungstate of Tungstic Chloride .... .... .... 36
Hydrochlorate of Tungstic Acid .... .... 37
Tungsten and Fluorine.
Fluoride of Tungsten.... .... .... .... 37
Tungsten and Nitrogen.
Nitrate of Tungstic Acid .... .... .... 37
Tungstate of Ammonia —
a. Monotungstate. — 6. Bitungstate .... .... 37
Sulphotungstate of Ammonium. — NH^S^WS' .... 38
Fluoride of Tungsten and Ammonium .... .... 38
Tungsten and Potassium.
Tungstate of Potash.
a, Monotungstate .... .... .... 38
b, Bitungstate .... .... .... .... 30
e. Hyper-acid Tungstate *.... .... 39
Sulphotungstate of Potassium.— KS.WS^ .... .... 40
Tungstate of Potash and Ammonia .... .... 40
Sulphotungstate of Potassium with Nitrate of Potash .... 40
Tungsten and Sodium.
Tungstate of Soda.
a. Monotungstate
b, Bitungstate ....
Tungstic Acid with Fluxes....
Sulphotungstite of Sodium.— NaS^WS' .... .... 42
Sulphotungstate of Sodium.— Na8,WS» .... 42
Tungsten and Lithium.
Tungstate of lithia.
«• Monotungstate.— A. Bitungstate .... .... 42
Tungsten and Barium.
Tungstate of Baryta.
a. Monotungstate — b. Bitungstate .... .... 43
Sulphotungstate of Barium .... .... .... 43
....
40
....
....
41
•...
42
CONTENTS. ix
Page
Tungsten and Strontium.
Ttmgstate of Strontia.
a. MoDotungstate .... .... .... 43
b. Biiungstate .... .... .... 44
SolphotungstateofStroniiam.— SrSyWS* .... .... 44
Tungsten and Calcium.
Tungstate of Lime ; run^f^^n .... ..^ 44
Sulphotungstate of Cftlciam.~€aS,W8* .... .... 44
Tungsten and Magnesium.
Tungstate of Magnesia .... •.„ ,.„ 45
Sulphotungstate of Magnesium •... .,•• 45
Tungsten and Cerium.
Sulphotongstate of Ceriom.— CeS^WS^ ».. .... 46
Tungsten and Yttrium.
Tongstate of Yttria .... .... ...• 45
Tungsten and Aluminum.
Tungstate of Alumina .... .... .... 45
Tungsten and Tborinum.
Tungstate of Thorina .>.« .... .... 45
Tungsten And Tantalum.
Tantalous Amd oontainiDg Tungsten .... .... 45
Tungsten and Tungsten.
Tungstate of Tongstons Oxide and Potash .... 45
Snlphotangstate of Potassium with Tungstate of Potash .... 46
Fluoride of Tungsten and Potassium with Tungstate of
Jt VHaBll . • . . .... .... .... .... vO
Tungstate of Tungstous Oxide and Soda ' .... 46
Fluoride of Tungsten and Sodium with Tungstate of Soda 47
Other Compounds of Tungsten .... .... .... 47
Chapter XIX. MOLYBDENUM.
MemoiiB^ &c. .... .... .... .... 48
History. Sources. Preparation .... «... .... 48
Properties .... •••• •••• .m* .... 49
COMPOUKDS OF MOLTBDEXUM.
Molybdenum and Oxygen.
Moljbdous Oxide. — ^MoO .... .... .... 49
Hydrate of Molybdous Oxide .... .... 50
Salts of Molybdous Oxide ; Moiybdous Salts .... 61
•»
••••
• »l»
M»»
V**
• ••»
«*••
•♦•1
• •••
C0NTBNT8.
Moljbdio Oxide.— MoO*
Hydrate of Molybdic Oxide ....
Salts of Molybdic Oxide ; Molybdic Salta
Olive-green Oxide of Molybdenum
Blue Oxide of Molybdenom
Molybdic Acid.— MoO'
Molybdic Add with Water
Molybdic Acid with other Aoida v-
Molybdates
Molybdenum and Boron.
Borate of Molybdons Oxide ,...
Borate of Molybdic Oxide ....
Borate of Molybdic Acid
Molybdenum and Phosphorus.
Phosphide of Molybdenum ....
Phosphates of Molybdous Oxide ....
Phosphates of Molybdic Oxide
Phosphates of Molybdic Acid
Molybdenum and Sulphur.
Molybdons Sulphide ; SulphomolybdoM A«id.-«Mo,S*
Molybdic Sulphide ; Sulphomolybdic Acid. — ^MoS' ....
Persulphomolybdic Acid. — MoS^
Sulphates of Molybdous Oxide
Sulphate of Molybdic Oxide
Sulphates of Molybdic Acid ....
Molybdenum and Iodine.
Hydriodate of Molybdous Oxide ....
Bydriodate of Molybdic Oxide
Molybdeaum cmd Cblorine.
Protochloride ; Molybdous Chloride. — ^MoCl
Bichloride; Molybdic Chloride.— MoCl*
Hydroohlorate of Molybdic Oxide ....
Molybdate of Terchloride of Molybdenum
Hydrochlorate of Molybdic Acid ....
Molybdenum and Fluorine.
Ilydroflnate of Molybdous Oxide
Hydrofluate of Molybdic OxideJ ....
Hydrofluate of Molybdic Acid
Molybdenum and Nitrogen.
Kitrate of Molybdous Oxide
Nitrate of Molybdic Oxide ....
Nitrate of Molybdic Acid
Molybdate of Ammonia.
a. Monomolybdate .... ....
bm Bimolybdate .... «t..
Page
51
62
62
6S
63
66
66
66
66
••*. 67
67
.... 68
68
58
68
68
69
60
61
62
62
62
••*.
...«
63
63
63
68
64
64
65
66
66
65
66
66
....
«7
CONTENTS. xi
Page
e. Hyper-acid Moljbdato .... .... .... 67
Carbonate of Molybdous Oxide and Ammoiiia .... 68
Carbonate of Molybdic Oxide and Ammonia .... .... 68
Phosphate of Molybdona Oxide and Ammonia .... 68
Sulphomolybdate of Ammonium. — NH'8,MoS^ .... 68
Persulphomoljbdate of Ammoniam. — NH'^SjMoS* 68
Hydrochlorate of Molybdona Oxide and Ammonia .... 69
Hydrofloate of Molybdona Oxide and Ammonia .... 69
Hydrofluate of Molybdie Oxide and Ammonia
Molybdenum and Potaasinm.
Molybdate of Potash.
a. Monomolybdato»^A. Bimolybdate .... 69
0. V Termolybdate.^^. IT Pentamolybdai^ .... 70
Carbonate of Molybdie Oxide and Potaali .... 70
Snlphomolybdate of Potassium.
Mono-add. — ^E8,MoS* .... „.; .... 70
Bi-acid.— ES,2MoS' .... .... 71
Persulphomolybdate of Potaatan«-HEQB^lIe8< .... 72
Sulphate of Molybdic Oxide and Potash.... .... 72
Hydrochlorate of Molybdous Oxide and Potash .... 72
Hydrofluate of Molybdous Oxide and Potash .... 72
Hydrofluate ofMolybdio Oxide and PotMh .... .... 72
Sulphomolybdate of Potannam with Nitre .... 73
Molybdenum and Sodium.
Molybdate of Soda.
a. Monomolybdate. — b, Bimolybdate. — e, Tennolybdate 73
Carbonate of Molybdic Oxide and Soda .... .... 73
Molybdic Add with Fluxes.... .... .... 73
Sulphomolybdate of Sodium. — ^NaS^MoS* .... .... 74
Persulphomolybdate of Sodium .... .... 74
Hydrofluate of Molybdous Oxide and Soda ... .... 74
Hydrofluate of Molybdio Oxide and Soda .... 74
Molybdenum and Lithium.
Sulphomolybdate of Lithium .... .... .... 74
Persulphomolybdate of Lithium .... .... 74
Molybdenum and Barium.
Molybdate of Baryta.
a. I>imelybdate.p— &• Mm— olybdate,. ..., 75
0. Five-halyes Molybdate .... .^ 75
d, Tennolybdate. — 0. Monomolybdate .... 76
Sulphomolybdate of Barium ..o .... ^.^ 76
Persulphomolybdate of Barium .... ^^ 76
Molybdenum and Strontium.
Molybdatp of Strontia .... .... ^.. 76
Sulphomolybdate of Strontium .... .... 76
Persulphomolybdate of Strontium.... ^^ -.. 76
Xll
CONTENTS.
Molybdenum and Calcium.
Molybdate of Lime ....
Sulphomolybdate of Galcimn
Pemilphomolybdate of Calcium ....
Molybdenum and Magnesium*
Molybdate of Ma^^nesia
Solphomoljrbdato of Magnesinm ....
Pemilphomolybdate of Magneeinm
Molybdenum and Cerium.
Molybdate of Cerons Oxide
Cerous Sulphomolybdate. — CeB^MoS'
Ceric Bulphomolyfodate.— Ce*SS3Mo8^
CerottB and Ceric PersulphomoIybdateB
Molybdenum and Yttrium.
Molybdate of Yttria ....
Salphomolybdate of Yttrium
Persolphomolybdate of Yttrium ....
Molybdenum and Glucinum*
Sulphomolybdate of Glucinnm
Pennlphomolybdate of Gluoinum....
Molybdenum and Aluminum
Molybdenum and Thorinum.
Molybdate of Thorina
Molybdenum and Silicium.
Silicate of Molybdoua' Oxide
Silicate of Molybdic Oxide
Hydrofluate of Silica and Molybdous Oxide
Hydrofluate of Silica and Molybdtc Oxide
fiydrofluate of Molybdic Acid and SiUca....
Molybdenum and Titanium
Molybdenum and Tungsten.
Tungstate of Molybdic Oxide.
Baaic Tungstate of Molybdic Oxide and Ammonia
Molybdenum aud Molybdenum.
KO,MoO» + KF,MoF»+2Aq. ....
Other Compounds of Molybdenum
•t«t
76
76
77
77
77
77
77
77
77
77
78
78
78
78
78
78
78
78
78
79
79
79
79
••*•
79
t.i. fV
80
CONTENTS.
• » *
X111
Chaptjbe XX. VANADroM.
0»M
• •••
HemoirSy &o» History
Sources. Preparation. Properties
OoMFOUKDs or Yavadium.
Vanadiam and Oxygen.
Suboxide of Vanadium.— VO
Vanadic Oxide ; Vanadous Acid. — ^VO*
Hydrated Vanadic Oxide
Salts of Vanadic Oxide ; Vanadic Salts
Vanadites
Oxides intermediate between VO* and VO^.
Purple Oxide
Green Oxide,— V0% 2 VO' ....
Yellow-green Oxide.— V0%4V0»
Orange-yellow Oxide
. Vanadic Acid. — ^VO'
Vanadic A-cid with Water .... ....
Vanadic Acid with stronger Acids
V anaoia tes .... .,,. ....
Pervanadio Add !
Vanadiam and Boron.
Borate of Vanadic Oxide
Tanadium and Phosphorus.
Phosphide of Vanadium
Phosphate of Vanadic Oxide
Phosphate of Vanadic Add....
Vanadiam and Solphur.
Vanadous Sulphide ; Sulphovanadous Acid. — ^VS*
Vanadic Sulphide ; Sulphovanadic Acid« — ^VS'
Sulphates of Vanadic Oxide.
a. Basic Sulphate.— 6. Bisulphate
Sulphates of Vanadic Add.
a, Basic Sulphate.— 6. Bisulphate ....
e, Tersulphate. — d. Hyper-acid Sulphate
Borate of Vanadous Sulphide
Vanadium and Iodine.
Bi-hydriodate of Vanadic Oxide ....
Vanadiam and Bromine.
Bi-hydrobromate of Vanadic Oxide
Vanadiam and Chlorine.
Bi-hydrochlorate of Vanadic Oxide
TcrclUoride of Vanadium ....
•t.»
Page
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1
Zir 00NTXNT8.
Vaosdinm and Fluorine.
Biflooride'of Tanadiiim m.. .•«• •^
Teiiiuoride of Ymtidigm ..^ ... ,^
Vanadinm and Nitrogen.
Nitrate of Yanadic Oxide .... .... •«
Nitrate of Yanadic Add ....
Yanadite of Ammonia
HypoTanadiate of Ammonia...
Yanadiate of Ammuiia*
a. MonoTanadiate
b, Biyanadiata
e. Hyper-acid Yanadiate
Carbonate of Yanadic Oxide and Amwimia
SnlpboTanadite of Ammonium ....
Solphovanadiate of Ammoninra
Banc Hjdrobromate of Yanadio Oxide and Anunonia
Banc Hjrdrochlorate of Yanadie Oxide and ^■*— ip»'*
Chloride of Yanadium and Animoniam
Vanadiom and Potassinm.
Yanadite of Potaah
Hypovanadiate of Potash
Yanadiate of Potadu
a. MonoTanadiate.— 6. BiYBnadlal6.-^a Hypw^eM
Yanadiate .... ..» .^
Carbonate of Yanadic Oxide and Potash .... .^
Snlphoyanadite of Potassium
Solphovanadiate of Potaasiam
Bnlpbate of Yanadic Oxide aad Potaah ....
Sulphate of Yanadio Acid and Potarii
Fluoride of Yanadium and Potassium ....
Vanadium and Sodionu
Yanadiate of Soda.
a, Monovanadiate. — b, BiTaaadiata
Yanadic Acid with Fluxes ....
Phosphate of Yanadic Acid and Soda •.-
Fluoride of Yanadium and Sodium
Vanadinm and Lithium.
Yanadiate of lathia.
a, Monovanadiate.— 6. Bivanadiate
Yanadium and Barium.
Yanadiate of Baryta.
a. Basic Yanadiate. — b, Monovanadiate.— «, BtTanadiate
Sulphovanadiate of Barium
Vanadium and Strontium.
Yanadiate of Strontia.
«• Basic Yanadiate.— 6. MonovBnadiate.-»0. Bivanadiate
F«ge
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100
100
100
100
100
100
101
101
101
101
102
.C0NTENT3.
XT
••••
... 102
102
«•••
••••
••••
102
103
Page
Sulphovanadiate of Sirontium «*m »«• 102
Vanadium and Calciam.
Yanadlate of Lime.
a. Basic Vanadiate. — b. Honovanadiaie, — c. Bivaaadiate 102
Sulphovanadiate of Calcium.. M .-.« •— 102
VaBftdinm and Ma^esiam.
Vanadiate of Magnesia.
«. Monovanadiate.— ft. Btvaaadlata
Vanadium and Yttrium.
Vanadiate of Yttria
Vanadium and Glucinum.
Vanadiate of Glncina....
Vanadium and Aluminum.
Vanadiate of Alumina
Vanadium and THorinum.
Vanadiate of Thorina.
a. Monovanadiate.— ft* Bivanadiate
Vanadium and Zirconium.
Vanadiate of Zirconia
Vanadium and Silicium.
Silicate of Vanadic Oxido
Phosphate of Vanadio Aoid and Silica ....
Hydroflnate of Silica and Vanadio Oxide
Hydrofluate of Silica and Vanadie Acid....
Vanadium and Tungsten.
Tungstate of Vanadic Oxide
Sulphotungstate of Vanadium
Vanadium and Molybdenum.
Molybdate of Vanadio Oxide
Other Compounds of Vanadium
103
103
103
]03
108
104
104
104
104
104
CHAFTsa XXI. CBBOMIUM.
Memoirs^ &c. History. Sourcea
Preparation. Properties
Compounds or Cbbomiuic.
Chromium and Oxygen.
^ Chromous Oxide. — CrO .... »...
Hydrate of Chromous Oxide
Sails of ChroMOus Oxide; Chromous Salts
.... 105
106
106
107
107
XTl
CONTENTS.
Page
107
108
112
113
^ Chromoso-dmmiic Oxide. — Cr*0*
Ghromic Oxide. — Cr*0*
Hydrate of Chromic Oxide ....
Salts of Chromic Oxide; Chromic Salts
Brown Oxide of Chromiam.
Monochromate of Chromic Oxide.— €r*0%CrOS or CrO* 113
Bichromate of Chromic Oxide.-— Cr'0',2CrO*, or CrH>* 1 15
Terehromate of Chromic Oxide.— Cr'O'^CrO', or Cr»0*« 116
AcidChromateof Chromic Oxide.— Cr'OVCrO*, or Cr*0» 116
Chromic Acid. — CrO*
AqneoQS Chromic Acid
Chromates .... .... ....
Perchromic Acid. — Cr"0' ....
Chromiiim and Carbon.
^ Carbonate of Chromous Oxide .... ....
Carbonate of Chromic Oxide
Chromiam and Boron.
f Borate of Chromons Oxide .... ....
Borate of Chromic Oxide ....
Chromiam and Phosphorns.
Diphosphide of Chromium
Phosphite of Chromic Oxide. ...
f Phospliate of Chromous Oxide ....
Phosphate of Chromic Oxide.
a. Neutral Phosphate.— 6. Acid Phosphate
^ Pyrophosphate of Chromic Oxide ....
^ Metaphosphate of Chromic Oxide
Chromium and Sulphar.
Sulphide of Chromium.
^ Protosulphide ....
Sesquisulphide
Tersulphide .... ....
^ Sulphite of Chromous Oxide
Sulphite of Chromic Oxide
Hyposulphate of Chromic Oxide
^ Sulpliate of Chromous Oxide
Sulphate of Chromic Oxide.
a. Two-thirds Sulphate.— 6. Bisulphate
c. Tersulphate .... .... ....
Sulphate of Brown Oxide of Chromium
Sulphate of Chromic Acid ?
Sulphocarbonate of Chromium
Chromiam and Selenium.
Selenite of Chromic Oxide.
Neutral Selenite.— Cr"0%3SeO*.— Acid Selenite
••••
116
no
110
ISO
121
122
122
122
122
123
123
123
123
123
123
124
124
124
125
125
125
125
126
128
128
120
1
129
IC
CONTENTS. XVii
Page
Chromium and Iodine.
Iodide of Chromium .... .... .... .... 1?9
lodate of Chromic Oxide .... .... .... 190
Chromium and Bromine.
SeBqaibromide of Chromium .... .... .... 130
Bromate of Chromic Oxide .... .... 130
Chromium and Chlorine.
^. Protochloride of Chromium ,... .... .... ISO
Subchloride of Chromium .... .... .... 131
Sesquichlorido of Chromium .... .... .... 131
Oxychloride of Chromium .... .... .... 134
Chlorochromic Acid. — CrO'Cl .... .... .... 136
Aqueous Hydroclilorate of Chromic Acid .... 137
Chromium and Fluorine.
^ Protofluoride of Chromium .... .... .... 137
Sesquifluoride of Chromium.... .... .... 137
Terfluoride of Chromium .... .... .... 138
Hydrofluate of Chromic Acid .... .... 139
Chromium and Nitrogen.
Nitride of Chromium.... .... .... .... 139
Nitrate of Chromic Oxide .... .... .... 140
Brown Nitrate of Chromium .... .... .... 140
Nitrate of Chromic Acid .... .... .... 140
Chromito of Ammonia .... .... .... 140
Chromate of Ammonia.
a. Monochromate .... .... .... 141
b. Bichromate .... .... .... .... 142
Carbonate of Chromic Oxide and Ammonia .... 142
Tersulphide of Chromium with Hydrosnlphate of Ammonia 1 42
Sulphate of Chromic Oxide and Ammonia : Ammonia Chrome*
M*(*#9V •«■• •*•• «••■ •*•• ••■■ AnBM
Terfluoride of Chromium with Ammonia .... 143
Sesquifluoride of Chromium with Hydroflnate of Ammonia 143
Chromate of Sal-ammoniac .... .... .... 143
Chromium and Potassium.
Chromite of Potash .... .... .... 144
Chromate of Potash.
a. Monochromate .... .... .... 144
b. Bichromate .... .... .... 146
Carbonate of Chromic Oxide and Potash .... .... 147
% Pyrophosphate of Chromic Oxide and Potash .... 147
Sulphide of Chromium and Potassium .... .... 147
% Sulphate of Chromous Oxide and Potash .... 147
Sulphate of Chromic Oxide and Potash.
a. Anhydrous .... .... .... .... 147
XVIll
CONTENTS.
Page
&. With 2 At Water .... ..., .... 148
e. With 24 At. Water ; PoUuh Chrom^-almm .... 148
Sulphate of Potaah with Chromate of Potash,
a. With Monocliroroate. — 6. With Bichromate .... 150
Chromate of Chloride of PotaaBiom .... .... 160
SeaqnifluoDde of Chromium with Flnoride of Prtaittinm .... 151
151
*..•
....
*n»
«...
f.i. *•••
Bidbromate of Potash with Nitrate of Potash
Chromium and Sodium.
Chromite of Soda
Chromate of Soda.
a. Honochromate ....
6. Bichromate ....
Cliromic Oxide with Fluzea....
Sulphate of Chromic Oxide and Soda s tferfe Ch r m i Mh m..
Chromate of Chloride of Sodium
Sesquifluoride of Chromium with Fluoride of Sodium
Chromate of Soda and Potash
Sulphochromate of Soda and Potash
Chromium and Lithium.
Chromate of lithia
Chromium and Barium.
Chromate of Bar/ta ....
Chromium and Strontium.
Chromate of Strontia
•*.«
•..«
Chromium and Calcium.
Chromate of Lime ....
Chromate of Chloride of CaloilitB.— €aCl|8CrO*
f Chromate of Lime and Potiah .«.«
Chromium and Magnesium.
Chromite of Magnesia .... ....
Chromate of Magnesia
Chromate of Chloride of Magnesium,-— MgCl|2CrO'
Chromate of Magnesia and Potash
Chromium and Cerium.
Chromate of Cerous Oxide.
a. Monochromate.-~5. Bichromate....
Chromium and Yttrium.
Chromate of Yttria.
a» Basic-chromate.— ^. Monochromate
Chromium and Glucinum.
Chromate of Glucina.
a. Basic-chromate.— 6. Acid-chromate
«.<
44..
151
151
152
152
152
152
152
152
152
153
153
153
153
154
164
154
154
154
164
154
155
155
i
CONTENTS. XIX
Page
Chromium and Tliorinam.
Chromateof Thorina.... ..,• »..« *•.« 15^
Chromium and Silicium.
Chromate of Silica I .... .... mm 155
Fluoride of Silimum and Chioinlimi «..• »..# 156
Chromium and Tungsten.
TuDgstaie of ChromiO Oxide .... »... 156
Chromium and Molybdenum.
Chromate of Molybdic Oxide.
a. Basic Chromate. — b» Biohromate .... .... 156
Chromate of Molybdic Acid .,., .... 156
Molybdate of Chromic Oxide .... .... .... 156
Sulphomolybdate of Chromium .... ..i. 156
Persulphomolybdate of Chromium .... .... 156
Chromium and Vanadium.
Chromateof Yanadic Oxide ' .... *... 157
Chromium and Iron .... *«« •*.« «..t 157
Chapteb XXn. URANIUM.
MemoirSi ftc. History '.... •••« .... ••*. 157
Souncee. FreparatioD. Properties .... .... ...f 158
COMFOUKDS OF UbAVIUM.
Uranium and Oxygen.
Suboxide of Unmium ? U*0^
UranoQS Oxides— UO
Hydrate of Uranons Oxide ....
Salts of Uranons Oxide ; Uranous Salts
Black Uranoso-uranic Oxide. — U^O^
Green Uranoso-munic Oxide. — U'O* ....
Hydrate of Uranoso-nranic Oxide «...
Salts of Uranoso-nranic Oxide ....
Uranic Oxide.— U«0»
Hydrate of Uranic Oxide
Salts of Uranic Oxide ; Uranic Salts
uranates .««. .... .... ....
Uranium and Carbon.
Carbonate of Uranoso-nranic Oxide
Carbonate of Uranic Oxide .... ....
Uranium and Boron.
Borate of Uranic Oxide .... .... .... 170
....
...»
....
150
159
...t
161
161
.*•*
161
161
•.»»
166
166
....
167
168
•*••
169
170
.*..
170
170
>
i*
XX . CONTENTS.
Pige
Uranium and PhoBphonis.
Phosphate of Uranoiii Oxide .... .... .... 171
Phosphate of Unaic Oxide.
f a. Triphosphate ... .... .... 171
% b. Diphosphate .... .... .... 171
e. Add Phosphate .... .... .... 172
Uraniam and Sulphur.
Protosnlphide of Unnium .... .... .... 173
Sulphite of UranonB Oxide.... .... .... 174
Sulphite of Uranic Oxide .... .... .... 174
Sulphate of Uranoua Oxide.
a. Disulphate .... .... .... 174
b. Monosulphate .... .... .... 175
Sulphate of Uranoso-urauic Oxide .... .... 176
Sulphate of Uranic Oxide.
0, Basic Sulphate.—^. Monosttlphate.^e. Bisulphate.—
<f. Tenulphate.... .... .... .... 177
Sulphocarhonate of Uranium t .... .... 178
Uranium and Selenium.
. Selcnite of Uranic Oxide.
a. Monoselenite, — b, Biselenite .... .... 178
Uranium and Iodine.
Protiodide of Uranium .... .... .... 178
lodate of Uianous Oxide .... .... .... 178
lodate of Uranic Oxide .... .... .... 178
Uranium and Bromine.
Protobromide of Uranium .... .... .... 179
Bromide of Uranous Oxide and Monohydrobromate of
Uranic Oxide.— 2U0,Br and U"0*,HBr .... .... 179
Bromate of Uranic Oxide .... .... .... I79
Uranium and Chlorine.
•
Three-fourths Chloride of Uranium .... .... 180
Protochloride of Uranium .... .... .... 180
Hydroclilorate of Uranous Oxide.... .... .... 181
Hydrochlorate of Uranoso-uranic Oxide .... 181
Chloride of Uranous Oxide; Chloride of Uranyl 181
Hydrochlorate of Ui'anic Oxide .... .... .... 182
Chlorate of Uranous Oxide .... .... .... 182
Perchlorate of Uranous Oxide .... .... .... 18?
Uranium and Fluorine.
Fluoride of Uranium .... .... «... 182
Uranium and Nitrogen.
Nitrate of Uranic Oxide.
a. Basic Nitrate. — b, ^fononiti'at^' .... .... 182
c. Temitmte .... .... .... 183
CONTENTS. XXI
Page
Uranate of Ammonia.... .... .... .... 183
Carbonate of Uranous Oxide and Ammonia .... 184
Carbonate of Urauic Oxide and Ammonia.
a. Neutral Salt .... .... .... .... 184
b. With a very large excess of Uranic Oxide I .... 185
Sulphate of Uranous Oxide and Ammonia .... .... 185
Sulphate of Uranic Oxide and Ammonia .... 185
Ammonio-chloride of Uranium .... .... .... 186
Chloride of Uranous Oxide and Ammonium^ or HydrochlO'*
rate of Uranic Oxide and Ammonia .... .... 186
Uranium and Potassiam.
Uranate of Potash .... .... .... 186
Carbonate of Uranic Oxide and Potash .... .... 187
Sulphate of Uranouer Oxide and Potash .... .... 187
Sulphate of Uranoso-uranic Oxide and Potash .... 188
Sulphate of Uranic Oxide and Potash .... .... 188
Chloride of Uranous Oxide and Potassium (Chloride of
Uranyl and Potassium) .... .... .... 188
Hydrated Chloride of Uranous Oxide and Potassium 189
Uranium and Sodium.
Uranate of Soda .... «... .... .... 189
Carbonate of Uranic Oxide and Soda .... •„i 189
Uranium \7ith Fluxes .... .... .... 189
^ Pyrophosphate of Ui-anic Oxide and Soda .... 190
Uranium and Barium.
Uranate of Baryta .... .... ... .... 190
Uranium and Calcium.
Uranate of Lime.
Carbonate of Uranic Oxide and Lime : Liehigife .... 190
Phosphate of Uranic Oxide and Lime : Calcareous Uranium^
mica or Calcareous Uranite .... .... .... 191
Sulphate of Uranic Oxide and Lime : Medjidite .... 191
Uranium and Magnesium.
Uranate of Magnesia .... .... .... .... 192
Uranium and Silicium*
Hydrofliuite of Silica and Uranous Oxide .... 192
Uranium and Tantalum.
Tantalate of Uranous Oxide : Uranotanlaliie .... «... 192
Uranium and Tungsten.
Tungstate of Uranous Oxide •,., .... 192
Tungstate of Uranic Oxide .... .... .... 192
VOL. IV. h
xxu
CONTKNTS.
Uranium and Molybdenum.
Molybdate ci Uimnow Ozidd
Molybdate of Uimnic Qzide....
Uranic Salphomolybdate
Unnic Permilphomoljbdate....
Uranium and Vanadium*
Tanadiate of Uranic Oxide
Uranium and Chromium.
Chromate of Uranic Oxide ....
Other Compounds of Uranium
••••
Page
.... 193
193
193
193
194
• ••, XV4
Ghapteh XXm. MANGANESE.
Memoirs, &c. '
HiBtoiy. Sources. Preparation
ProperiieB ....
COMPOUKDS OP MaXOANZSZ.
••M
• •*•
194
.... 196
196
Manganese and Oxygen.
ManganouB Oxide. — MnO
Hydrate of Manganous Oxide
Salts of Manganous Oxide ; Manganous Salts
Manganoso-manganic Oxide. — ^Mn'O* ....
Hydrate of Manganoso-manganic Oxide ....
Salts of Manganoso-manganic Oxide
Manganic Oxide. — ^Mn*0^
Hydrate of Manganic Oxide
Salts of Manganic Oxide; Manganic Salts
Ores of Manganese containing more than 1| At. and less
than 2 At. Oxygen to 1 At. Manganese : Piilomeiane, ^c. 203
Peroxide of Manganese. — MnO"
Hydrated Peroxide of Manganese.
a. One-fourth hydrated.— 4MnO', HO
fi. Tri-hydrated.— 3MnO%HO
y. Di-hydrated.— 2MnOSHO
d. Mono-hydrated.~-MnO%HO
Ores of Manganese, principally containing Hydrated
Peroxide: Wad
, , Manganic Add. — ^MnO* ....
Manganates
Permanganic Add. — Mn*0^
Aqueous Permanganic Add....
Permanganates
197
198
199
200
202
202
202
203
203
204
205
206
206
207
207
208
208
209
209
210
212
CONTENTS. :&xiii
Page
Manganese and Carbon.
Carbide of Manganese! .... .... „.. 213
Carbonate of Manganons Oxide : JlfafyaM«#-«f»ar ...» 213
Manganese and Boron.
Borate of Manganons Oxide ...» •..« »..• 214
Manganese and Phosphoms.
Phospbite of Mangaaese .... .... .... 214
Hypopbosphite of Manganons Oxide .... .... 215
Phosphite of Manganons Oxide .... .... 215
Phosphate of Manganons Oxide .... .... .... 216
^ Diphosphate.— 2MnO,HO,PO'+6Aq. .... 216
f^ Acid Phosphate.— MnO;2HO;PO»+2Aq. .... 216
^ Pyrophosphate of Manganons Oxide .... .... 217
Metapbosphate of Manganons Oxide .... .... 217
Phosphate of Manganic Oxide .... .... 217
Manganese and Sulphur.
Sulphide of Manganese. — "MjoS : Manffonese-hlende .... 218
Hydrated Sulphide .... .... .... 219
Oxysulpbide of Manganese. — ^MnS^MnO .... .... 219
Hyposulphite of Manganons Oxide ...» ^.t 220
Sulphite of Manganons Oxide ,.., ..., .... 220
Hyposnlphate of Manganons Oxide .... .... 220
Sulphate of Manganons Oxid&
a, Monobydrated. — /9. Bi-hydra(ed .... .... 221
y. Ter-hydrated.— ^. Tetza-hydrated .... 222
€. Penta-bydrated. — (. Hepta-hydraied .... .... 223
f/. Aqueous solution .... .... ..^ 224
Sulphate of Manganoflo-mangaaie Oxide .... .... 224
Sulphate of Permanganic Acid! .... .... 224
Sulphide of Carbon and Manganese .... .... 225
Hyposulphophosphate of Manganese .... 225
Manganese and Selenium.
Hydroseleniate of Manganons Oxide .... .... 226
Selenite of Manganons Oxide.
a. Monoselenite.«— (. Biselenite .... .... 226
Manganese and Iodine.
^ ^ ' Protiodide of Manganese, and Hydriodate of Manganons
\^AilQ0 .... ..a. .... .••* •>•. £mv
Hydriodate of Manganic Oxide .... .... 226
lodate of Manganons Oxide .... .... .... 227
Mangaaese and Bromine.
Bromide of Manganese .... .... .... 227
Hydrated Bromide .... ...^ .... 227
Bromate of Manganons Oidde .... «... 227
52
XXIV CONTENTS.
Manganese and Chlorine.
«. . Protochloride of Manganese .... .... .... 227
' • Hydrated Protocliloride .... .... 228
Hydrochlonite of Manganic Oxide .... .... 229
Terehloride of Manganese?.... .... .... 229
' ChlorafSi of MangaifOfis Oxide .... .... .... 230
Percldorate of Manganous Oxide .... .... 230
Manganese and Flnorine.
Protoflnoride of Manganese .... .... .... 230
Sesquifluoride of Manganese .... .... 230
Seven-halves Fluoride of Manganese .... .... 230
Manganese and Nitrogen.
Nitrite of ^fanganous Oxide .... .... 231
Nitrate of Manganous Oxide .... .... .... 231
Permanganate of Ammonia.... ... .... 231
Carbonate of Manganous Oxide and Ammonia .... 231
Phosphate of Manganous Oxide and Ammonia .... 231
' Ammonio-sulphate of Manganous Oxide .... .... 232
Balphate of Manganous Oxide and Ammonia.
Sulphate of Manganic Oxide and Ammonia : Ammonia Man'
gtanese^alunt .... .... .... .... 233
' Hydrocfalorate of Manganous Oxide and Ammonia .... 233
Manganese and Potaasiam,
. Manganate of Potash : Mineral Chameleon .... .... 233
Permanganate of Potash .... .... .... 235
% Sulphide of Manganese and Potassium '.... .... 237
Sulpliate of Manganous Oxide and Potash .... 238
Sulphate of Manganic Oxide and Potash : Potash Man-
ganese-alum .... .... .... .... 238
Fluoride of Manganese and Potassium .... .... 238
Manganese and Sodium.
Manganate of Soda .... »... .... .... 238
Permanganate of Soda .... .... .... 238
Manganese with Fluxes .... .... .... 239
Sulphide of Manganese and Sodium .... .... 239
Sulphate of Manganous Oxide and Soda.
a. Bi-Iiydrated .... .... .... .... 239
/3. Sex-hydrated .... .... .... 240
Fluoride of Manganese and Sodium .... .... 240
Pyrophosphate of Manganous Oxide, Soda^ and Ammonia 240
Manganese and Lithium.
Permanganate of Lithia .... .... .... 241
Manganese and Barium.
Manganate of Baryta.... .... .... .... 241
Permanganate of Baryta .... .... .... 241
CONTENTS. XXV
Page
Manganese and Strontium.
. MaDganate of Strontia •... .... .... 242
Pennanganate of Strontia ,... .... .... 242
Manganese and Calciiun.
Permanganate of lime .... .... .... 242
Manganese and Magnesium.
Permanganate of Magnesia.... .... .... 242
Manganese and Aluminum.
Sulphate of Alumina and Manganous Oxide ..,. .... 242
Manganese and Silicinm.
Silicate of Manganous Oxide.
a. Disilicate .... .... .... 242
b. Monosilicate .... .... .... .... 243
o; Tetrasilicate .... .... .... 244
Silicate of Manganic Oxide.
a. Trisilicate: Heterocline .... .... 244
b. Disilicate .... .... .... .... 244
Hydroflnate of Silica and Manganous Oxide .... 244
Manganese ^vith Glass-fluxes .... .... .... 246
Silicate ofGlucina and Manganous Oxide : Hehine.... 245
Silicate of Alumina and Manganous Oxide.
Hydrated : KarpholUe .... .... k .... 246
Manganese and Titanium.
Titanate of Manganous Oxide : GreenovUe .... 245
Manganese and Tantalum.
Tantalide of Manganese ; .... .... .... 246
Manganese and Tungsten.
Tungstate of Manganous Oxide.
a, Monotungstate.-*^. Bi tungstate .... .... 246
Sulphotungstate of Manganese. — MnS,WS' .... 246
Manganese and Molybdenum.
Molybdate of Manganous Oxide .... .... .... 246
Sulphomolybdate of Manganese.
a. With excess of Sulphide of Manganese .... 247
6. In equal numbers of Atoms. — MiiS,MoS' .... 247
0. With excess of Sulphomolybdic Acid .... 247
Persulphomolybdate of Manganese .... .... 247
Manganese and Vanadium.
Yanadite of Manganous Oxide .... .... 247
Vanadiate of Manganous Oxide.
a. Monovanadiate. — 5. Bivanadiate .... .... 247
Manganese and Chromium.
Chromide of Blanganese .... .... .... 247
•*••
•••«
248
• •••
• •••
249
•«••
• •••
260
«•••
••••
2A1
XXn CONTENTS.
Page
Chromate of Kaaganoiu Oxide.
a, Dichromate .... .... .... ,... 247
h, Monochromatet .... ..^ ..^ 248
Other Compounds of Manganese .... .... ..^ 248
Chaptze XXIY. arsenic.
MfemoifVy Ac* .... ....
Hiftoiy. Sonroes
Prepaimiion .... „., ,„.
Properties <... .... ....
CoKPOviTDs or Aaszifxc,
Arsenic and Oxygen.
Suboxide of Arsenic. — ^AsOl .... .... .... 262
Arsemons Add. — ^AsO* .... .... .... 263
Aqneons Solution of Arsenions Acid .... .... 267
Compounds of AsO' with oth^ Adds .... 269
Arsenites .... .... ,,., ,,,, 269
Arsenic Acid.-— AsO".
Crystallized Arsoiic Add.— Aqueous Solntion .... 262
ATtifmitiffM 9JKI
Arsenic and Hydrogen.
Solid Arsenide of Hydrogen.— AsH* t .... 264
Arseninretted Hydrogen. — ^AsH* .... .... 264
Manh\i test for Arsenic .... .... 268
Distinction between Arsenic spots and Antimony spots 269
Arsenic and Phosphorus.
Phosphide of Arsenic .... .... .... 271
Phosphate of Arsenions Add .... .... 271
Arsenic and Sulphur.
Sub-sulphide of Arsenic. — ^As^S .... 27I
Hypo-anenions Sulphide ; Hyposulpharsenious Add.->AsS* 271
Hyposulpharsenites .... .... ^.. 272
Arsenions Sulphide; Sulpharsenious Add, AsS' .... 273
Aqueous Solution, or Hydrosulphate of Arsenions Acid 274
Bulpharsenites .... .... .... 276
Arsenic Sulphide; Snlpharsenic Acid. — AsS' .... 277
Sulpharseniates .... .... .... 277
Octodeca-sulpbide of Arsenic .... .... .... 279
Persulphide of Arsenic .... .... .... 280
^ Sulphoxiarsenic Acid. — AsO'S* .... .... .... 280
Sulphate of Aneuious Acid .... .... 280
/V
CONTSNTS. xxvii
Page
Arsenic and Selenium.
Selenide of Anenio ..v. .... ..^ .... 280
Arsenic and Iodine.
Teriodide of Arsenic .... .... .... 281
Arsenite of Teriodide of Araenio .... .... 282
Hydriodate of Teriodide of Anenio .... •,.. 283
Penta-iodideof Arsenio (AqneeiiftBolaliea) .... .... 283
Arsenic and Bromine.
Teriiromide of Arsenic .... .... .... 283
Arsenite of Bromide of Arsenio ...« .... 284
Arsenic iind Chlorine.
Terchloride of Arsenia
Hydrated Terohloridei or Ter-hydrooUorate of|Ane-
nious Acid .... .... .... 286
Chloride of Sulphur and Arsenic .... .... 286
Arsenic and Fluorine.
Terflaoride of Arsenic .... .... .... 286
Arsenic and Nitrogen.
Arsenite of Ammonia : Arsenical Sai-^mm<miac
a. Basic Salt — b. Acid Salt .... .... .... 287
Axseniate of Ammonia.
a, Tris-arseniate.— 6. Bi-arseniate .... 287
0. Mono-aneniate .... .... ••.. 288
Hypoaulpharsenite of Ammonia .... .... 288
Ammonio-tersulphide of Arsenio .... .... 288
Snlpharsenite of Ammonium.
a.Terbasic.— 3NH«S,AsS*;— 5.Biba8ic.^2NH%^* 288
Ammonio-pentasnlphide of Arsenic .... .... 289
Snlpharseniate of Ammonium.
a. Terhasic— 3NH'S, AsS''.— 6. Bibasio.-^aNH'a, AsS»
0. Monobasic, NH'S, AsS*.--</. With 12 At. acid,
NH-S,12AsS» ..., .... .... 289
Ammonio-chloride of Arsenic .... .... 289
Amn<mio-fluoride of Arsenic ...t •..« •••• 290
Arsenic and Potassium.
Arsenide of Potassium .... .... .... 290
Arsenite of Potash.
^ a. Di-arsenite.— •2K0, AsO\ .... .... 291
^ (. Mono-arsenite. — ^KO^AsO' .... .... 291
IT e. Bi-arsenite.— KO,HO,2AsO*+Aq. .... .... 291
Arseniate of Potash.
«. Tris-aneniate.— SKOjAsO* .... 291
b. Di-aneniate.— 2EO,A80* .... .... 291
e. Mimo-arseniate. — KO,AsO' .... .... 292
XXVIU
CONTENTS.
Hyposalpbarsenite of Potassiiim.
a. Terbasic — SKS^AfiS* .... ....
b, Bibasic— 2KS,A8S*
«.' Monobasic. — KS^AsS* .... ....
Sulpbarsenite of Potassium,
a. Terbaaic— SKS^AsB'
^ Bibasic— 2K8^A8S'
€• Monobasic— KSyAflS'
d. With excess of Acid
Sulpbaiseniate of Fotassimn.
a, Terbasic— ^KS^AsS'
b. Bibasic— 2K8,AsS>
e. Monobasic — ^KS^AsS'
d. With 12 At. acid.— KS,12A8S»
Sulphoxiarseniate of Potash. — KOTO'S' + Aq. ..
Arseniate of Iodide of Potassiom. — KIiSAsO'
Arsenic and Sodiam.
Arsenide of Sodium
Anenite of Soda
Arseniate of Soda.
a. Tris -arseniate
b, Di-arsenate. — c, Mono-araeniate
Hyposnlpharsenite of Sodium
Sulpbarsenite of Sodium ....
Sulpbarseniate of Sodium.
a. Terbasic — a. Anhydrous. — fi. Crystallized
b. Bibasic— «. Monobasic
d. With 12 At. Sulphur-acid
Arseniate of Soda and Ammonia
Sulpbarseniate of Sodium and Ammonium
Arseniate of Soda and Potash
Sulpbarseniate of Sodium and Potassium
Arsenic and Lithium.
Sulpbarsenite of Lithium
Sulpbarseniate of Lithium.
a. Terbasic — 5. Bibasic Salt
c. M'onobasic— (^. With 12 At. acid
Arsenic and Barium.
ff
Arsenite of Barjrta.
If a. Di-arsenitc — 6. Mono-arsenite
Arseniate of Baryta.
a, Tris-arseniate. — b. Di-arseniate
c, Mono-arseniate
Hyposnlpharsenite of Barium
Sulpbarsenite of Barium.
a. Terbasic— 6. Bibasic
Page
•...
292
292
».>•
292
293
••*•
293
293
*••.
293
293
• •I.
293
293
..•«
293
294
..«•
294
294
«*..
29ft
.•«.
295
297
*...
297
297
.••«
297
298
.■..
298
298
••a.
298
299
.... ddfj
299
.... 300
.... 300
300
.... 301
301
.... 301
9 '
CONTENTS* xxix.
Page
SulphAneniate of Barium.
0. Terbasic .... .... .... 301
(• Bibasic.— o« Monobasic-^cf. With 12 At. acid ...." 302
Arsenic and Strontium.
Arsenite of Strontia .... ...« .... 302
Arseniate of Strontia*
a. Di-arseniate.-^d. Mono-arBeniate! ...• .... 302
Hypoeulpbanenite of Strontium. '
a. Terbasic— (. Bibasio .... .... 302
Arsenic and Calcium.
Araenite of Lime.1
a. Di-arsenite .... .... .... .... 302
h. Mono-anenite .... .... .... 303
e. Axsid Salt .... .... .... .... 304
Arseniate of Lime.
a. Tria-arsemate. — h, Di-arseniate .... 304
e. Mono-aneniate .... .... .... 305
Hypoenlpharsenite of Calcium .... .... 306
Sulpharaenite of Calcium.
a. Terbafiio.^6. Bibasic .... .... .... 305
SnlpharBeniate of Calcium.
a. Terbaaib. — 6. Bibaaio .... .... 305
Arseniate of Lime and Ammonia .... .... 306
Arsenic and Magnesium.
Arsenite of Magnesia .... .... .... 307
Arseniate of Magnesia.
a. Di-arseniate.— &. Mono-aneniate .... 307
Hyposulpharsenite of Magnesium .... .... 307
Sulpharaenite of Magnesium .... .... 307
Sulpharseniate of Magnesium.
a. Terbasic— 6. Bibasic .... .... .... 307
Arseniate of Magnesia and Ammonia .. . .... 307
Sulpharseniate of Magnesium and Ammonium .... 308
Arseniate of Lime and Magnesia : BerMeliiiej Pieropharmacolite 308
Arsenic and Cerium.
Cerous Arseniate .... .... ... 308
Ceroua Hyposulpharsenite .... .... .... 300
Cerous Sulpharaenite. — ^2CeS,A8S' .... .... 309
Cerous Sulpharseniate .... .... .... 309
Cerio Sulpharseniate.— 2Ce'8'^AsS' .... .... 309
Arsenic and Yttriam.
Arseniate of Yttria .... .... .... .... 309
Sulpharseuite of Yttrium .... .... . .. 309
Sulpharseniate of Yttrium .... .... .... 309
CONTENTS.
Anenic and Olacinam.
Anenide of Glaciniim
Ar—iMtii of Olaeina
Sulpbanenite and Snlphazwiiiate of Gladnnm
AneDic and Alnminam.
Anenide of Alnnunnin .... •«.
Aneniate of Atamia*
Anenic and Thorinnm.
Aneniate of Thorina
Anenic and Zirconium
Aneniaie of Ziroonia
Hypofiilphanenite of Zirconiam
Solphanenite of Zirooniiim
Snlphaneniate of Zirconiiim
Anenic and Silicium.
Aneniate of Silica t
GlaflB containing Anenions Acid ..^
Anenic and Titaninm.
Aneniate of Titanic Oxide
Anenic and Molybdennm.
Aneniate of Molybdons Oxide ...,
Aneniate of Molybdic Oxide
Aneniate of Molybdic Acid
Molybdic Bulphanenite
Anenic and Vanadium.
Aneniate of Tanadic Oxide
Aneniate of Tanadio Add
Arsenic and Chromium.
Aneniate of Chromic Oxide
Chromic SulpharBenite.— 2Cr'8S3AaS*
Chromic Sulphaneniate
Arsenic and Uranium.
Arseniate of Uranons Oxide,
a. Terbasic. — b, Bibasic
Arseniate of Uianic Oxide.
^ a. Di-arseniate. — 6. Mono-areeniate
^ Aneniate of Uranic Oxide and Soda ....
Uranic Sulpharaenite
Uranic Sulphaneniate
Arsenic and Manganese.
Arsenide of Manganese
Pi«e
310
.... 810
310
.... 310
310
310
....
VAV
310
.■a.
310
310
....
311
311
*.*t
311
311
••«•
311
311
1...
311
312
. ...
312
312
• •.*
312
312
....
313
313
I... 919
313
.... 314
314
314
CONTENTS. xxxi
Page
Arseniate of Manganous Oxide.
a. Bibasic. — b. Monobasic .... ,... 314
Hyposulpharsenite of Manganeee.
Suipharseniate of Manganese.
a. Sexbasic— 6Mn8,A8S^— d. Bibasic.— -9MnS,A8S* 316
Arseniate of Manganous Oxide and Ammonia .... 315
Other Compounds of Arsenio .... »... 316
Chapter XXV, ANTIMONY.
MemoirSy &o« .... .... •..« •.• .... 316
History. Sources .... .... .... .... 317
Preparation .... .... .... .... .... 319
jrroperues .... .... .... .... ..k 322
CoMPoirirDs of Antimokt.
Antimony and Oxygen*
Suboxide of Antimony. — SbO! ....
Antimonic Oxide, SbO'
Hydrated Antimonic Oxide ....
Salts of Antimonic Oxide; Antimonic Salts
Antimonious Acid, SbO^.
Hydrated Antimonious Acid
Antimonites
Antimonic Add.—- SbO' .... ....
Hydrated Antimonic Acid
Antimoniates .... .... .... .... 332
t.«.
• ••«
323
324
....
327
327
*•..
329
330
• ».«
330
331
Antimony and Hydrogen.
Solid Antimonide of Hydrogen? .... ,,.. ?32
Ajitimoninretted Hydrogen. — SbH' .... .... 333
Antimony and Phosphorus.
Phosphide of Antimony .... .... .... 335
Phosphite of Antimonic Oxide .... .... .... 336
Phosphate of Antimonic Oxide .... .... 336
^ Pyrophosphate of Antimonic Oxide .... ...• 336
Antimony and Snlphur .... .... .... 336
Antimonious Sulphide; Sulphantimonious Acid. — ^SbS*.
a. CrysiBMlzed: Grey Sulphide of Antimonjf .... 337
b. Amorphous : Mineral Kermee .... .... 340
Sulphantimonites .... .... .... .... 353
Tetrasulphide of Antimony? .... .... 354
Antimonic Sulphide; Sulphantimonic Acid. — SbS' .... 354
Sulpbantimoniates .... .... .... 353
^ /
XXXIl CONTENTS.
Page
Ozysulphide of Antimony.
. a. Reguhu Antimomi medieinalii .... .... 359
b. /InHmonialBlende.^^hO^^hS^ .... 359
e, Croeu» Animonii .... .... .... 359
d, Glau rf AnHmonyy VUrum AntimwUi .... 360
Sulphite of Aniimonic Oxide .... .... .... 360
Sulphate of Antimonic Oxide.
«. Ditulphate. — 6. Monosulphate.— c. Tervulphate.-*
e. Quadrosulphate .... .... .... 361
Antimony and Selenium.
Selenide of Antimony ..,. .... .... 362
Oxyselenid^ of Antimony .... .... .... 362
Antimony and Iodine.
Teriodide of Antimony .... .... .... 362
Basic Hydrioddte of Antimonic Oxide .... .... 363
Add Hydriodate of Antimonic Oxide .... .... 365
lodoralphide of Antimony .... .... .... 363
Iodide of Antimony with Sulphide of Antimony .... 364
Antimony and Bromine.
Terbromide of Antimony .... .... .... 364
Baric Hydrobromate of Antimonic Oxide .... .... 365
Antimony and Chlorine.
Terchloride of Antimony .... ... .... 365
Oxychloride of Antimony .... .... .... 367
Acid Hydrochlorate of Antimonic Oxide .... 368
Aqaeous Solution of Acid llydrochlorate of Antimonions
^AwlU ■■»• •••• •••• •••• •«•• *MMr
Fentachloride of Antimony .... .... 369
Pentachloride of Antimony with Phosphuretted Hydrogen 370
Bichloride of Sulphur with Pentachloride of Antimony 870
Teraulphide of Antimony with Pentachloride of Antimony 370
Antimony and Fluorine.
Terfluoride of Antimony .... ... .... 37I
Tetrafluorido and Pentafluoride of Antimony .... 371
Antimony and Nitrogen.
Nitrate of Antimonic Oxide .... .... 371
Antimonic Oxide with Ammonia .... .... 371
Antimonite of Ammonia .... .... .... 372
Antimoniate of Ammonia.
% a. Bibasic (Meta-)antimoniate.— 6. Mono-antimoniate 372
Sulphantimoniate of Ammonium .... .... 372
Ammonio-terchloride of Antimony .... 373
Ammonio-pontachloride of Antimony .... .... 373
Terchloride of Antimony with Sal-ammoniac .... 374
CONTENTS.
•
XXXlll
Page
• r
• •••
• «••
374
• ••t
• ••t
•.•• 375
Antimony and Potasdiiim.
Antimonide of Potassium ....
Antimonic Oxide with Potash
Antimonite of Potash.
a. Mono-antimonite. — 6. bi-antimonite .... .... 375
Antimoniate of Potash.
Tf a, Bibasic. — b. Monobasic .... .... 376
c. Di-acid or Dibasic .... «... ...« 377
Snlphantimonite of Potassium .... .... 378
Sulphaatimoniate of Potassium .... .... .... 380
Sulphantimoniate of Potassium with Antimoniate of Potash 381
Chloride of Antimony and Potassium .... .... 381
Antimony and Sodium.
Antimonide of Sodium .... .... .... 382
Antimohio Oxide with Soda .... .... .... 382
Antimonite of Soda .... .... .... 382
Antimoniate of Soda .... .... .... .... 382
Antimony with Fluxes .... .... .... 383
Snlphantimonite of Sodium .... .... .... 383
Sulphantimoniate of Sodium (SehlippeU Salt) .... 384
Chloride of Antimony and Sodium ".... .... ..«. 388
Antimony and Barium.
Antimonite of Baryta .... .... 388
Antimoniate of Baryta .... .... .... 388
Sulphantimonite of Barium .... .... 388
Sulpliantimoniate of Barium ...» •..» .•.. 388
Antimony and Strontium.
Sulphantimoniate of Strontium .... .... 389
Antimony and Calcium.
Antimonite of Lime .... .... .... .... 38.9
Antimoniate of Lime .... .... .... 389
Sulphantimoniate of Calcium .... ...» .... 389
Antimony and Magnesium.
Sulpliantimoniate of Magnesium .... .... 390
Antimony and Silicium.
Hydroflaate of Silica and Antimonic Oxide .... .... 390
Antimony and Molybdenum. •
Molybdate of Antimonic Oxide . .... .... 390
Antimony and Vanadium.
Yanadiate of Antimonic Oxide .... .... .... 390
Antimony and Chromium.
Chromate of Antimonic Oxide .... .... 390
XXXIV CONTENTS.
Page
Antimony and Uraninm.
Antimoniate of Uranons Oxide .... .... .... 391
Uranic Sulphantimoniate .... .... .... 391
Aniimon J and Manganese.
Antimoniate of Manganoiu Oxide .... .... 391
Kaoganous Sulphantimoniate .... .... 391
Antimony and Arsenic.
Anenide of Antimony .... .... .... 391
Azwnite of Antimonic Oxide .... .... 392
Aneniate of Antimonic Oxide .... .... .... 392
Aneniate of Antimonic Acid .... .... 392
Sulpharaenite of Antimony .... .... ...• 392
Bulpharseniate of Antimony .... .... 392
Anenide of Antimony and Potassinm .... .... 392
Other Compounds of Antimony .... .... 392
ChapteeXXVI. TELLUBIUM.
M.&ai(nt§f &c. .... .... .... .... 393
History. Sources. Preparation .». .... ..m 393
Properties ..., .... .... .... .... 396
COMPOUKDS OF TxLLnaiux.
Tellnrinm and Oxygen.
Telluric Oxide or Tellnrons Acid.— TeO* .... .... 397
. Hydrated Telluric Oxide or Tellurous Acid .... 398
Aqueous Solution of Tellurous Acid .... .... 398
Salts of Telluric Oxide.... .... .... 398
Tellurites .... .... .... .... 400
Tdluric Acid.— TeO» .... .... .... 400
Hydrate of Telluric Acid .... .... .... 402
Crystallized Telluric Acid .... .... 402
Tellurates .... .... .... .... 403
Tellurium and Hydrogen.
Solid Telluride of Hydrogen.... .... .... 404
Hydrotelluric Acid.— TeH» .... .... .... 404
Tellurium and Sulphur.
Sulphides of Tellurium.
a. Bisulphide; Tellurous Sulphide; SulphotelluronsAcid 406
b. Tersulphide; Telluric Sulphide; Sulphotelluric Acid 400
c. Tetrasulphide.... .... .... .... 406
Sulphate of Tellurous Oxide ! .... .... 406
Sulphate of Telluric Oxide.
a. Basic Sulphate.^5. Bisulphate .... .... 407
CONTENTS* XXXV
Page
Tellorium and Selenium.
Selenide of Tellmiiim .... .... .... .... 408
Tellnrinm and Iodine.
Subiodide of Tellnrivm .... .... .... 408
Protiodxde of Tellurium ; Telluriclodide .... .... 408
Biniodide of Tellurium; Tellnric Iodide .... 408
Tellurite of Telluric Iodide .... .... .... 409
Hydriodate of Telluric Iodide .... .... 409
Teriodide of Tellurium^ or Hydriodate of Telluric Iodide 409
Periodlde of Tellurium .... .... .... 410
Tellarium and Bromine.
Snbbromide of Tellurium ...• .... 410
Protobromide of Tellurium; TeUurouB Bromide .... 410
Bibromide of Tellurium ; Telluric Bromide ^.„ 410
Tellurite of Telluric Bromide •.., ^^ .... 411
Tellarium and Chlorine.
Subchloride of Tellurium .... .... .... 411
Protochloride of Tellurium; Tellui«u8 Cidoride .... 411
Bichloride of Tellurium; Telluric Chloride .... 412
Tellurite of Telluric Chloride .... .... .... 412
Hydrochlorste of Telluric Chloride L.. ...* 413
Hydrochlorate of Telluric Acid .... .... .... 413
TeUurium and Fluorine.
Bifluoride of Tellarium; TellaricFlaoride .... .... 413
Tellurite of TeUurio Fluoride .... .... 413
Tellurium and Nitrogen.
Nitrate of Telluric Oxide .... .... .... 413
Bi-hydroteUurate of Ammonia .... .... 414
Tellurite of Ammonia.
a. Monotellurite.— 6. QuadroteUurite .... .... 414
Tellurate of Ammonia.
a. Monotellurate. — b, Bitelluiate .... .... 414
2 2' ^ Quadrotelluraie .... .... .... 416
SulphoteUurite of Ammoma.--3NH^>Te8* .... 416
lodotellurate of Ammonium .... .... .... 415
Chlorotellurite of Ammonium .... .... 415
Chlorotellurate of Ammonium .... .... .... 415
Tellurium and Potassium.
Tellnride of Potassium .... .... .... 416
Tellurite of Potash. .... .... .... 416
a, Monotellurite.-^5, Bitellorite .... .... 416
0, QuadroteUurite .... .... .... 417
XXXVl
CONTENTS.
Page
Tellurate of Potash.
a. Monotellurate
b. BiteUumte
c* Qaadrotellurate
a. Containing the Solulile Hodificatioii of TeQaric Add
/9. Containing the Inaolnble Modification •...
Sulpbotellurite of PotaflBiam
lodotellurate of Potassiam
Bromotellurate of Potassiam
Chlorotellarate of Potassium
TcUurinm and Sodium.
Telluride of Sodium
ToUariteofSoda.
a. Monotellurite.— '6. Bitellnrite
e. Quadrotellurito
Tellurate of Soda.
a. Monotellurate. — 6. Bitellurate
c. Quadrotellurate.
u. Containing the Soluble Modification of Telluric Add
, fi. Containing tlie Insoluble Modification ....
' Tellurous Acid with Fluxes.
Sttlphotellurite of Sodium.— 3KaS,TeS'
lodotellurate of Sodium
Flnotellurate of Sodium
.... 417
418
.... 419
419
.... 419
420
.... 420
420
.... 420
420
.... 420
421
.... 421
422
.... 422
422
.... 422
422
Tellurium and Lithium.
Tellurite of Lithia.
a. Monotellurate.— 6. Bitellurate. — c. Quadrotellurate 422
Tellurate of Lithia.
a and 6. Monotellurate and Bitellurate .... .... 423
c. Quadrotellurate .... .... .... 42.S
Sulphotellurate of Lithium .... .... .... 423
Tellurium and Barium.
Tellurite of Baryta.
a. Monotellurite. — 6. Qnadrotellurite
Tellurate of Baryta.
a. Monotellurate. — b. Bitellurate
c, Qaadrotellurate
Sulphotellurite of Baiium
Tellurium and Strontium.
Tellurite of Strontia
Tellurate of Strontia
Sulphotellurite of Strontium
Tellurium and Calcium.
Tellurite of Lime.
a. Monotellurite.— 6. Bitellurlto.- c. Quadrotellurite, 421
423
423
424
424
424
424
424
CONTENTS.
Tellnrate of Lime ....
8ulphotelliirite of Oalciiim ....
Tellarium and Magnesinm.
Tellurite of Magnesia
Tellnrate of Mag:nesia.
a. Monotellnrate.-^. Bite!ln»t«
Snlpbotellnrite of Magneeinm
Tellarium and Gerinm.
Cerous Solphotellurite
Tellarium and Yttrium.
Tellnrite of Yttria ....
Tellnrate of Yttria
Tellarium and Olacinum.
Tellnride of Glncinum
Tellnrite and Tellarate of Glncina
Tellurium and Aluminum.
Tellnride of Aluminum
Tellurite of Alumina
Tellurate of Alumina
«»«•
Tellurium and Thorinum.
Tellurite and Tellurate of Thorina
Tellurium and Zirconium.
»•.*
»■*!
•**»
.Itl
• ••*
••••
••••
»•••
TeUurite of Zirconia
TeUorate of Zirconia
Tellurium and Chromium.
Tellurite of Chromic Oxide
Tellnrate of Chromic Oxide
Tellurium and Uranium.
Tellurite of Uranic Oxide .
Tellurate of Uranio Oxide
Tellurium and Manganese.
Tellurite and Tellurate Oa MangaaouB Oidde
Other Compounds of Tellurium .*».
!*.»
.*•*
MM
MM
«...
».••
XZXVll
Page
MM 484
424
.... 424
425
M.. 425
425
.fM
««u
425
t*.*
425
425
• *..
425
425
ft*.
425
420
426
426
426
426
426
MM 426
••M
426
426
Chapteb XXVII. BISMUTH.
MemoiFSj &c. .... .... ••••
History. Sources. Preparation. Propertiee
•M.
• ••»
C
427
427
XXXVIU
CONTENTS.
Fige
CoxPouiTDs OF Bismuth.
Bismuth and Oxygen.
Suboxide of Bismuth?
Bismuih-ozide. — ^BiO*
Hydrate of Bismuth-oxide
Salts of Bismuth-oxide; Biflmuthnaalts
\ Peroxide of Bismuth. — ^BiO^
Bismuthic Acid. — ^BiO' t
f Hydrate of Bismuthic Acid
^ Bismuthates
Bismath and Hydrogen.
Hydride of Bismuth 1
Bismath and Carbon.
Carbonate of Bismuth-oxide
Bismuth and Boron.
Borate of Bismuth-oxide
Bismuth and Phosphorus.
Phosphide of Bismuth
Phosphite of Bismuth-oxide
Ordinary Phosphate of Bismuth-oxide
Pyrophosphate of Bismuth-oxide
Metaphosphate of Bismuth-oxide
Bismuth and Sulphur.
Bisulphide of Bismuth
Tersulphide of Bismuth
Sulphite of Bismuth-oxide ....
Sulphate of Bismutli-oxide*
a. Monosulphate
&. Bisulphate.— 0. Tersulphate.'
Sulphocarbonate of Bismuth
Bismuth and Selenium.
Selenide of Bismuth ....
Bismuth and Iodine.
Iodide of Bismuth
a. Subiodide
b, Teriodide
Oxy-iodide of Bismuth
Iodide of Bismuth and Hydrogen
lodate of Bismuth-oxide
Bismuth and Bromine.
Bromide of Bismuth ....
Bromate of Bismuth-oxide ....
•*••
..••
•*M
428
429
.1.. ^■•*
430
430
431
.... 432
433
.... 433
433
Acid Sulphate
433
433
433
434
434
434
434
434
436
435
436
430
436
436
t.M
••1*
••.t
t.M
• it. 490
437
437
437
437
,... 438
438
CONTENTS.
Biflmnth and Chlorine.
Chloride of Bismuth .... .... ....
Hjdnited Chloride^ or Ter-hydrochlorate of
oxide ^...
Oxychloride of Bismnth
Add Hjdrochlorateof Biamath-ozide ...«
BiBmnth and Flaorine.
Flaoride of Bismuth ....
Bismnth and Nitrogen.
Nitrate of Bismuth-oxide.
0, Mononitrate
& Temitrate
e, Aqneous Solution of Acid Nitrate
Ammonio-iodide of Bismnth
Ammonio-chloride of Bismuth
Chloride of Bismuth and Ammonium
Bismnth and Potassinm.
Bismuthide of PotaBsium
f Bismuthate of Potash
Sulphate of Bismuth-oxide and Potash
Bismuthate of Bismuth-oxide and Potash.
a. Ochre-yellow.— 6. Brown
0. Purple .... .... ....
f Iodide of Bismuth and Potassium
Cliloride of Bismuth and Potassiimi
Bismnth and Sodium.
Bismuthide of Sodium
Bismuthate of Bismuth-oxide and Soda
Chloride of Bismuth and Sodium
Bismnth and Silicium.
Silidde of Bismuth : Bumuth4iknd4 or BismuihUt
Bismnth and Tnngsten.
Sulphotungstate of Bismuth
Bismnth and Moljbdennm.
Moljbdate of Bismuth-oxide
Snlphomolybdate of Bismuth
Persulphomolybdate of Bismuth
Bismnth and Chrominm.
Chromate of Bismuth-oxide
Page
.... 438
Bismuth-
439
.... 489
440
t... ^4v
440
.... 443
443
.... ^44
.... 4M
....
444
446
....
446
....
446
446
...a
447
447
....
447
447
....
448
448
.••• 44o
448
.... 448
448
.... 449
zl OOlfRKTS.
Bismnth and Araenio.
Page
Arsenide of Biemttth; A n e ni C'ffkmc i .... .... 449
Aneniate of Bismnth-ozide .... .... .... 449
Snlphanenite of Bismiith.^SBiS*,8Ai8* .... 449
Solphaneniate of BiflBuUi.— 2Bi8>;iAlS* .... .... 449
Bismnth and Antimony.
Antimonide of Bismuth .... ..•• mm 449
Snlphantimoniaie of Bismuth .... .... ••.. 450
Bismnth and Tellnriom.
Telluride of Bismuth .... ..». .... 450
Sulphide of Bismuth with Tellnride of Bimiith.-»2BiTe*y
BiSK^Tellurie Biimuth .... .... .... 450
Bulphotellurite of Bismuth ...» «m« 450
Other Compounds of Bismuili .... .... .... 450
METALS,
(Contin'iied,)
Chapter XVII.
TANTALUM
Hatcliott. Crell Ann, 1802, 1, 197; also Scher. J, 9, 3(33; also Gilb. 11,
120.— Further: Crell. Ann. 1802, 1, 257 & 352.
Ekeberg. iSchr, J, 9, 597; also Crell. Ann, 1803, I.
Wollaston. Schw. 1, 520; also Gilb. 37, 98.
Gabn, fierzelius & Ef^gertz. Schw, 16, 437.
Berzelius. Pogff, 4, 6.
Wbhler. Po^^. 48, 91; also Ann, Fharm, 31, 12(J.
H. Rose. Pogg, 63, 307 and 693; 69, 1 18; alsoi^. Ann. Ckim. Phys. 13,
and 350; 19, 165.
Stnontmes: Columhium, Tantale, Tantal.
Bistory. — Discovered by Hatcbett, in 1801, as Oolumhium, in an Ame-
rican mineral, and by Ekeberg in 1802 as Tantalum, in two Swedish
minerals. Wollaston, in 1809, pointed out the identity of these two
metals. Berzelius, in 1824, prepared pure metallic tantalum and many
of its compounds previously unknown. IT In 1846, H. Rose discovered
that thometal hitherto called tantalum and regarded as a simple substance,
is really a mixture of at least two different metals, and in some cases
probably of three. The name of tantalum is retained for one of the three
allied metals, and the other two have received the names of Niobium and
Pelopium, The following details, therefore, excepting where otherwise
expressly indicated, must be understood to refer to tantalum as it was
understood previous to Rose's investigations. IT
Sources. — As tantalic acid (rarely tantalous acid) in combination with
various salifiable bases in Tantalite, i ttro-tantalite, Euxenito, Ferguson ite,
Pyrochlore, and Urano-tantalite. {Vid. Niobium and Pelopium, p. 15.)
Preparation and Properties, — 1. Anhydrous fluoride of tantalum and
potassium is heated with potassium, and the fluoride of potassium, which
VOL. IV. B
2 TANTALUM.
is produced with incandescence, dissolved oat bj water.^-Black, heavy
powder, which becomes iron-grey under the burnishing st«e1j it does not
conduct electricity, or at least with great difficulty, probably in conse-
quence of its pulverulent state. Very refractory in the fire. (Berzelius.)
2. When tautalic acid is heated in a charcoal crucible in a blast-furnace,
tantalous acid is formed, surrounded with a thin, yellowish stratum of
reduced tantalum, having a faint metallic lustre; this stratum conducts
electricity very well, and when polished with agate, acquires a high
metallic lustre and a more decided iron-grey colour. (Berzelius, LehrbtuX,.)
3. Children {Schw, 16, 365), by exposing tantalicacid to the influence
of his powerful voltaic battery, obtained very brittle granules of a red-
dish yellow colour.
IT 4. By passing dry ammoniacal gas over chloride of tantalum ignited
in a tube. (Rose, Fogg. 69, 115.)
The tantalum prepared by the first and fourth methods takes fire
in the air at a lower temperature than that obtained by the second. (Ber-
zelius.) IT
Compounds of Tantalum,
Tantalum and Oxygen.
A. Tantaloub Acid. TaO*.
Oadde of Tantalum, — Occurs in the form of tantalite of protoxide of
iron, in the Tantalite of Kimito.
Preparation, — Ignited tantalic acid is pressed into a cavity not larger
than a quill, made in the middle of a charcoal crucible, and ignited for an
hour in the strongest heat of a blast-furnace. A trace of metallio tan-
talum is produced on the surface only.
Properties. — Unfused, porous, dark grey mass, having the form of the
bore, only more contracted. When rubbed on the whetstone, it acquires
a metallic steel-grey colour. It scratches glass and yields a dark brown
powder, destitute of metallio lustre; it is a non-conductor of electricity.
(Gahn, Berzelius & Eggertz.) Ekeberg, by exposing oxide of tantalum
to a white heat in a charcoal crucible, obtained a moderately hard,
blackish grey mass, having somewhat of the metallic lustre; Hatohett
obtained a black powder.
Berzeliot.
Ta 185 .... 92-04 9202
20 16 .... 7-96 7-98
TaO» 201 .... 100-00 100*00
(TaO = 1153-72 + 100 = 1253-72. BeraeUua.)
Tantalous acid is not reduced when treated with zinc and aqueous hydro-
chloric acid, after ignition; that which contains sulphuric acid and has
been previously dried, becomes blue, without being dissolved; but if moist
it dissolves, yielding first a fine blue and afterwards a dark brown solu-
tion (hydrochlorate of tantalous acid?). Ammonia added to this solution
precipitates dark brown flakes (of hydrated tantalous acid?), which again
bec4>rae white on exposure to the air. (WoUler.)
TANTAUC ACID,
B. Tantalio Aoid. TaO*.
Oxide of Tantalum, TanUaloxifd^ Tantalerde, Acide Tantaliqite, O^yde de
TarUale.
Formation, — 1. Tantalum prepared bj the first method, takes fire in
the air at a temperature considerably below redness, and bums with great
splendour, yielding pure tantalic acid. When fused with hydrate or car-
bonate of potash, it decomposes the water or carbonic acid and forms
tantalate ot potash. It dissolves in aqueous hydrofluoric acid, with rise
of temperature and evolution of hydrogen gas; and very rapidly in a mix-
ture of hydrofluoric and nitric acids. Nitric acid, after long boiling,
dissolves only a trace; boiling oil of vitriol behaves in a similar manner,
and its action is increased by the addition of nitric acid. Hydrochloric
> acid or nitric acid alone, and solution of caustic potash, have no action on
the metal. (Berzelius.)
2. Tantalous acid does not absorb oxygen in the air at ordinary tem-
peratures; the peculiar odour which it evolves in a moist atmosphere,
arises from the presence of a small quantity of manganese. When
heated to redness it becomes incandescent and remains so, provided the
temperature be kept up, till the whole is converted into greyish white
tantalic acid; during this process, it absorbs from 3*5 to 4*2 per cent, of
oxjgen. Ignited with potash or nitre, it yields tantalat-e of potash; in
the latter case a slight explosion occurs. It is not afi'ected by hydro-
chloric acid, aqua-regia, hydrofluoric acid, or a mixture of hydrofluoric
and nitric acids. (Gahn, Berzelius & Eggertz.)
Preparation, — 1 . Levigated tantalite is fused with 2 parts of hydrate
of potash; the resulting mass dissolved in hot water; and the filtered
Bolntion supersaturated with hydrochloric or nitric acid; the hydrated
tantalio acid is then precipitated (though not entirely: Berzelius) in white
flakes, which are purified by washing with water. (Ekeberg.) — 2. One
part of tantalite is ignited with 5 parte of carbonate of potash and 2 parts
of borax, and the fused mass digested in water and supersaturated with
hydrochloric acid; hydrated tantalic acid then remains, and must be well
washed with pure water. (Wollaston.) — 3. A mixture of one part of finely
divided tantalite and from 6 to 8 parts of bisulphate of potash is heated
to redness in a platinum crucible, till the whole fuses to a perfectly clear
liquid, and no undissolved matter can be observed at the bottom of the
crucible. The mass, when cold, is reduced to powder, and repeatedly
boiled with fresh quantities of water, till no more sulphate of potash, iron,
or manganese is dissolved; the undissolved hydrate of tantalic acid con-
taining sesquioxide of iron, binoxide of tin, and tungstic acid, is digested
with bihydrosulphate of ammonia, which removes the two latter sub-
stances, and converts the ferric oxide into ferrous hydrosulphate ; the
liquid is then filtered; and the insoluble tantalic acid washed with water
containing bihydrosulphate of ammonia. The washed residue is boiled with
concentrated hydrochloric acid till its green colour is changed to white; the
hydrochloric acid poured off; and the hydrated tantalic acid washed with
boiling water. (Berzelius.) — The hydrate prepared by either of these pro-
cesses may be converted into pure tantalic acid by ignition. — To obtain it
as free as possible from silica, the hydrate must be dissolved in aqueous
hydrofluoric acid; the filtered solution mixed with sulphuric acid and
B 2
"T
4 TANTALUM.
evaporated to dryness ; and the residue ignited as long as it loses weight;
the whole of the silica is then expelled in the form of gaseous fluoride of
silicium. (Berzelias.)
Propertiet. White infusible powder; fixed in the fire, tasteless and
inodorous; does not redden litmus; specific gravity = Q'S. (Ekeberg.)
Assumes a lemon-yellow colour every time it is heated. (Wiihler.) IT The
specific gravity ot tantalic acid varies considerably, according to the tem-
perature to which it has been exposed, and also according to its molecular
condition. The specific gravity of the amorphous acid, prepared from the
chloride and heated to the point of incandescence over a spirit-lamp, is
7*280; that of the crystallized acid [obtained by precipitation ?1 is =
7 '284. On exposing these acids to the heat of a strong charcoal nre for
four hours, the specific gravity increased to 7*851, and in one instance to
7*9944; but when they were ignited in a porcelain- furnace, the specific
gravity was reduced to 7*783, the acid remaining unchanged in appear-
ance. Specific gravity of tantalic acid obtained from the Ytterby tantalite
= 7 '43. The greatest and the least observed specific gravities of tantalic
acid are respectively, 8*264 and 7*022.
Ta
185 ..
88-51
11-49
Berzelius.
88-487
30
24 ..
11-513
TaO»
209 ..
.. 10000
100000
Ta20» = 2 . 1153-72 + 3 . 100 = 260744. (Bcnelios.)
Deeompotitians. In the circuit of a powerful voltaic battery, tantalio
acid is reduced to the metallic state. TChildren.^ — 2. When exposed to a
white heat in contact with charcoal, it is partly reduced to the metallic
state, and partly to tantalous acid; by passing hydrogen gas over tantalic
acid heated to redness in a tube, it is converted, though with a scarcely
perceptible loss of weight, into a grey (bluish-black: W'dhler) oxide,
which, when ignited in the air, again becomes white. (Gahn, Berzelius 6c
^gg^T^^') Probably a mixture of tantalic with tantalous acid. (Wohler.)
— 3. By ignition with bisulphide of carbon, tantalic acid is converted into
sulphide of tantalum, carbonic oxide, and free sulphur: TaO' + 3CS' =
TaS' -h SCO 4- 3S. — 4. Heated with hydrofluoric acid, it yields fluoride of
tantalum. IT 5. Tantalic acid remains colourless when ignited in an atmo-
sphere of hydrogen or hydrosulphuric acid gas, but when ignited in a
current of ammoniacal gas, it turns grey and yields a small quantity of
water. (Rose.) IT
Combinations, a. With Water: — Hvdrated Tantalic Acid. — Ob-
tained by precipitating a solution of tantalate of potash in water by
hydrochloric acid, and washing the precipitate with hot water, till it
passes through the filter free from hydrochloric acid. Snow-white, bulky
precipitate, which reddens litmus-paper when laid on it in a moist state,
and becomes orange -coloured when treated with infusion of galls. (Gahn,
Berzelius & Eggertz.)
Calcolation. Gahn, Berzelius & Eggeiis.
TaO» 209 .... 88-56 88*83 to 89*5
3 HO 27 .... n -44 1117 „ 10-5
TaO*,3HO 236 .... 10000 ~. foOOO „ lOO'O
When heated in a retort, it evolves water which is neutral to test-
paper, and leaves the pure acid behind (Gahn, Berzelius & Eggertz);
BORATE OF TANTALUM. 5
according to BerzelioB^ an emission of light is sometimes observed during
this process. Becomes phosphorescent by ignition. (Rose.)
h. With Acids : — Tantalic acid, after ignition, is (according to Berze-
lius) insoluble in all acids, unless it has been again fused with potash or
bifiulphate of potash. The hydrated acid dissolves abundantly in hydro*
fluoric acid and acid oxalate of potash — slightly in sulphuric and hydro-
chloric acid — and not at all, or in very small quantity, in nitric, oxalici
tartaric, citric, acetic, or succinic acid, or in cream of tartar. (Gahn,
Berzelius & Eggertz.) These solutions are colourless; some of them yield
a precipitate on the addition of water; others form a white opaque jelly
with concentrated aqueous solution of phosphoric acid. Alkaline carbi>-
nates and hydrosulphates disengage carbonic acid or sulphuretted hydro-
gen, and throw down white flakes o^hydrated tantalic acid. Ferrocyanide
of potassium communicates a yellow colour to a solution of tantalic acid
in acid oxalate of potash. Infusion of galls, provided the solution does
not contain too large an excess of acid, produces an orange colour, and
when added in larger quantity, a precipitate of the same colour. - H This
precipitate is not produced in the presence of non-volatile organic acids,
and is moreover redissolved by caustic alkalis. (Rose.) IT Zinc gives a
white precipitate.
c. With Salifiable Bases, forming the Tantalates. Tantalic acid has
a greater affinity for bases, and especially for the fixed alkalis, than for
acids. It yields with them soluble and insoluble compounds, both in the
Wet and in the dry way. The stronger acids throw down hydrated
tantalic acid from solutions of its salts, in the form of a milk-white
precipitate which is characterized by its insolubility in acids and by not
imparting a colour to fluxes before the blowpipe. Tincture of galls throws
down an orange-coloured precipitate from an alkaline (acid, Bose) solution
of tantalic acid, provided the alkali is not in very great excess. Hydro-
sulphate of potash and ferrocyanide of potassium do not produce any
precipitate.
IT Alkaline tantalates are completely precipitated by chloride of
ammonium and sulphate of ammonia at ordinary temperatures. The
precipitate is an acid salt, containing both fixed alkali and ammonia.
The precipitate produced in alkaline tantalates by hydrochloric acid,
redissolves in an excess of the acid, forming an opalescent solution which
is but partially precipitated by sulphuric acid, even on boiling. The
alkaline salts are decomposed by a current of carbonic acid; nence a
neutral solution of tantalate of soda becomes turbid on exposure to the
air. Tantalate of soda acidulated with sulphuric acid yields a yellow
flocculent precipitate with ferrocyanide of potassium, and a white precipi-
tate with the ferricyanide : the former is slightly soluble in a large quan-
tity of hydrochloric acid. When a solution of tantalate of soda is mixed
with an acid, and a piece of zinc is plunged into it, a white precipitate of
tantalic acid is formed after some time. The insolubility of tantalate of
soda in excess of caustic soda or carbonate of soda, and consequently
the fact that a strong solution of this salt is precipitated on the addition
of either of these reagents, is a character which distinguishes this acid
from all others (excepting niobic and pelopic acid), more especially from
tnngstic acid, which it otherwise much resembles. (Rose.) IT
Tantalum and Boron.
Borate of Tantalic Acid. — Tantalic acid dissolves in melte4
boracic acid, yielding a colourless glass. (Ekeberg.)
TANTALUM.
Tantalum and Phosphorus.
Phosphide of Tantalum has not yet been prepared.
Phosphate of Taktalic Acid.—- a. Tantalic acid fuses with phos«
phoric acid; forming a colourless glass (blue^ when tungstic acid is present).
(Ekeberg.)
h. A concentrated aqueous solution of phosphoric acid added to a
solution of tantalic acid in sulphuric or hydrochloric acid, causes the
separation of a white^ opaque jelly. (Tb^nard.)
Tantalum a^ Sulphur.
A. Sulphide of Tantalum. — 1. Tantalum heated in sulphur-vapour
takes fire at a temperature approaching redness, and burns with great
rapidity, forming sulphide of tantalum. (Berselios.) — 2. Vapour of bisul-*
phide of carbon is passed over tantalic acid at a white heat — as in the
preparation of sulphide of titanium (p. 477). (H. Rose, Gtlb. 73, 139.)
No sulphide of tantalum is produced by igniting tantalum with sulphur;
or by igniting tantalic acid with sulphur or cinnabar, or in a current of
hydrosulphuric acid gas. (Gahn, Berzelius & Eggertz.) Tantalic acid is
not decomposed, either in the dry or wet way, by sulphide of potassium,
(Berselius )
Grey, smooth, fine-grained mass, which can be compressed into steel-
grey lumps, having a metallic lustre, resembling graphite in appearancoi
and conducting electricity. (Rose, Berzelius.)
According to Berzelius.
Ta 185 79-40
3S 48 20-60
TaS" 233 10000
Sulphide of tantalum, when heated in the air to incipient redness,
bums with a bluish, sulphurous fiame, and is converted into tantalic acid,
the sulphur being driven out and replaced by oxygen. A portion of
sulphuric acid, however, is so strongly retained by the tantalic acid, thai
it can scarcely be got rid of, except by ignition with carbonate of ammo-
nia. 100 parts of sulphide of tantalum yield from 89*6 to 89*743 parts
of tantalic acid. Sulphide of tantalum ^sed with hydrate of potash in
A close vessel, dissolves, and forms a yellowish red mixture of tantalate
of potash with double sulphide of tantalum and potassium, translucent
and greenish blue at the edges. On the addition of water, this substance
immediately becomes black, in consequence of the reproduction of sulphide
of tantalum, the whole of the potash being dissolved in the free state by
the water. The sulphide of tantalum [hydratedfj thus precipitated, is a
black powder, which appears dark greenish blue by transmitted light.
When not protected from the air, it oxidises in a few hours, and is con-
verted into white tantalic acid. When chlorine gas is passed over sul-
phide of tantalum at ordinary temperatures, the sulphide becomes heated
in the course of two hours, and is converted, without incandescence, into
chloride of tantalum and chloride of sulphur. The decomposition is faci-
litated by heat. A mixture of hydrofluoric and nitric acids dissolves
sulphide of tantalum, leaviug a residue of sulphur; boiling aqua-rcgia
converts it into sulphuric acid and tantalic acid, the latter of which
remains almost wholly undissolved. Sulphuric acid, hydrochloric acid,
CHLORIDE OF TANTALUM. 7
hydroflnoric acid, nitric acid, and caustic potash; have no action on
sulphide of tantalum. (Berzelius.)
B. Sulphate op Tantalic Acid. — a, Basic Sulphate, — ^Water added
to the solution h, precipitates tantalic acid, which obstinately retains a
portion of the sulphuric acid, and parts with it only on ignition — more
readily however on the addition of carbonate of ammonia. The same
compound remains when sulphide of tantalum is burned. (Berzelius.) It
likewise separates from a fused mixture of tantalic acid and bisulphate of
potash on the addition of water. It is soluble^ while moist, in hydrochloric
acid and solution of potash. (Wi^hler.)
6. Acid SSulphate, — Hydrated tantalic acid dissolves sparingly in oil
of vitriol From this solution water precipitates the compound a.
Tantalum and Chlorine.
A. Chloride op Tantalum. — TaCl^ — Tantalum heated in chlorine
gas burns with great rapidity, producing a dark yellow vapour which
condenses to a yellowish white, amorphous powder. This compound is
also obtained by gently heating the mixture of chloride of sulphur and
chloride of titanium — formed by the action of chlorine on sulphide of
tantalum (see above^ — till the chloride of sulphur is volatilized. Chloride
of tantalum is resolved by water, with violent hissing and evolution of
heat, into insoluble, translucent tantalic acid and aqueous hydrochloric acid,
which retains but a small portion of tantalic acid in solution. (Ber-
zelius.) IT Volatilizes at 144°; fuses at 221°. Treated with concen-
trated sulphuric acid at ordinary or at slightly elevated temperatures, it
dissolves and forms an opalesceut solution, which, when boiled, becomes
very turbid, and on cooling, yields a white opalescent jelly, insoluble in
aciaulated water. Dissolves in hydrochloric acid at ordinary tempera-
tures, yielding a cloudy solution, which, after some time, forms a tolerably
firm jelly. On treating this substance with water, traces of tantalic acid
dissolve, and are not thrown down by boiling. Boiling hydrochloric acid
does not dissolve it completely, but the solution does not gelatinize on
cooling; if water be now added, an opalescent solution is formed, which
may be boiled without further change; sulphuric acid, even at ordinary
temperatures, produces after some time a voluminous precipitate. Chloride
of tantalum is not completely decompose<l by boiling water; but water
containing a small quantity of ammonia decomposes it perfectly at ordi-
nary temperatures, the acid separating in flakes which are readily collected
on a filter. Solution of potash does not dissolve it completely; solution
of carbonate of potash leaves it untouched, even on boiling. It does not
blacken when exposed to a current of bydrosulphuric acid gas at ordinary
temperatures, but when heated in the gas, it evolves hydrochloric acid and
is converted into sulphide of tantalum. (Rose.) IT
B. Tantalate of Terchloridb op Tantalum 1 — ^When dry chlorine
gas is passed over an ignited mixture of tantalic acid and charcoal, a white
sublimate is obtained, which fumes slightly in the air, and is converted by
heat into a colourless vapour which condenses to a concentric, fibrous,
silky mass. Sometimes the sublimate fuses partially on the application
of heat, in which case it yields a yellow vapour, as though it contained
an excess of chloride of tantalum: this is probably caused by the use of
a larger quantity of charcoal. The compound is decomposed by water
with disengagement of heat and separation of gelatinous tantalic acid
8 TANTALUM.
containing hydrochloric acid ; with hydrochloric acid, on the contrary, it
forms a clear solution. (Wdhler.)
0. Hydrociilorate of Taktaltc Acid. — 1. Prepared by boiling
hydrated tantalic acid with s»qaeou8 hydrochloric acid. — 2. By mixing
chloride of tantalam with water.— 3. By dissolving B in hydrochloric
acid. The solution is not rendered cloudy by water. Ou evaporation,
it deposits the tantalic acid in the translucent state. The solution obtained
by the third method is not clouded by boiling, except when concentrated;
and in that case it again becomes clear on the addition of water; sulphuric
acid, even at ordinary temperatures, precipitates nearly all the tantalic
acid. (Wbhler.)
The tantalic acid containing sulphuric acid (p. 1, B, a.) dissolves
with tolerable facility in concentrated hydrochloric acid, and in large
quantity after long digestion. This solution, when diluted with water,
becomes turbid on boiling, and gives a white precipitate of tantalic acid
containing sulphuric acid. By sulphuric acid also and its salts, the
tantalic acid is almost wholly precipitated from the solution, in combi-
nation with a small quantity of sulphuric acid, in the form of a heavy,
milk-white precipitate: the precipitation is immediate if the liquid is hot
or concentrated ; gradual when it is cold and dilute. (Wdhler.)
Whereas pure chloride of tantalum is decomposed by water, depositing
the greater part of the tantalic acid, chloride of tantalum mixed with
chloride of sulphur (as it is obtained in the decomposition of sulphide of
tantalum by chlorine) dissolves completely in water, with the exception
of a small quantity of sulphur which is set free. The solution is, how-
ever, rendered turbid by heat, and deposits gelatinous tantalic acid on
evaporation. (Berzelius.) [The sulphuric acid produced from the chlo-
ride of sulphur, is probably the cause of this difference of behaviour in
the chlorine compound.]
Tantalum and Fluorine.
A. Fluoride op Tantalum. — Formed by evaporating acid hydro-
fluate of tantalic acid to dryness. White, opaque, amorphous mass,
which is neither volatilized nor decomposed at a red heat, dj water, it
is resolved into acid hydrofluate of tantalic acid which dissolves, and
insoluble tantalic acid which retains a portion of hydrofluoric acid. It
unites with other metallic fluorides, forming Tantalo-Fluorides, which
are permanent in the fire, but when treated with hot water, have a ten-
dency to be resolved into a white, insoluble powder containing excess of
tantalic acid, and a solution containing a larger proportion of acid. (Ber-
zelius.)
B. Basic hydrofluate op Tantalic Acid. — a. Ignited tantalic
acid is disintegrated by aqueous hydrofluoric acid, but not dissolved ; it
likewise absorbs a portion of the hydrofluoric acid, which it evolves again
on ignition. (Berzelius.) h. The precipitate produced by the action of
water on fluoride of tantalum.
C. Acid hydrofluate op Tantalic Acid. — Hydrofiuotantalic Acid.
It appears to be as yet undecided whether this compound is teira-
hydrofluaU of tantalic acid = TaO', 4HF, (or supposing 3H0 to be
separated, == TaF^ HF) ; or whether it is penta-hydrojlxiate of tantalic
acid = TaO', 5HF (or, subtracting 3H0, = TaF», 2HF). Hydrated tan-
TANTALATE OF POTASH. 9
talic acid, prepared according to the third method (p. 3), dissolves
instantly in aqueous hydrofluoric acid. Any tantalite which may have
remained undecomposed, or any portion of tantalic acid, which, though
it has given up its protoxide of iron to the bisulphate of potash, has
not itself been dissolved — is left behind. The clear solution, evapo*
rated spontaneously at first, and afterwards at a temperature of 30^,
deposits crystals of acid hydroflnate of tantalic acid, together with fluo-
ride of tantalum formed on the edge of the basin by the volatilization of
the excess of hydrofluoric acid« The crystals, by mere efflorescence in the
air — ^whereby they lose hydrofluoric acid and water — are converted into
fluoride of tantalum; this change is produced more rapidly by heat.
The salt, when recently prepared, dissolves in water without decomposi*
tion. (fierzelius.)
Tantalum and Nitroqen.
A. Tantalate of Ammonia. — Hydrated tantalic acid digested with
ammonia, forms with a portion of that substance, an insoluble compound
wliich does not redden litmus paper, and, when heated or exposed to
the air for a long time, again evolves the ammonia. With salts of the
earths or of the heavy metallic oxides, this compound yields, by an
Interchange of elements, a tantalate of the earth or of the metallic
oxide. (Gahn, Berzelius & Eggertz.) When a potash-solution of tantalic
acid containing sulphuric acid, is mixed with excess of sal-ammoniac,
a precipitate of tantalate of ammonia is obtained, which, when ignited
out of contact of air, leaves bluish-black tantalic acid. (Wohler.)
B. In carbonate of ammonia, tantalic acid is but very sparingly soluble.
(Berzelius, Lekvbuch,)
C. Fluoride of Tantalum with Hydropluate of Ammonia, or
Fluoride of Tantalum and Ammonium. — According to Berzelius^
this compound consists of NH^F, TaF^ Acid hydroflnate of tantalic acid
is mixed with ammonia till a permanent precipitate begins to appear, a&d
the mixture is then evaporated to a small bulk. SoBiIy crystals. This
compound, when heated in a platinum vessel, evolves a sublimate of
hydroflnate of ammonia, together with a trace of fluoride of tantalum ;
while the residue consists of pure fluoride of tantalum. With water it
readily forms an acid solution and deposits a white powder ; the liquid
on being boiled, deposits an additional quantity of powder. (Berzelius.)
Tantalum and Potassium.
A. Tantalate of Potash. — Tantalic acid fuses with hydrate of
potash ; it likewise expels carbonic acid — by fusion, but not in the wet
way — from carbonate of potash. (Berzelius.) If the mass is allowed to
cool before the decomposition is complete, the solidified crust is broken
by the carbonic acid disengaged from the interior, just as in the case
of titanate of potash (HI*? 484.) (H. Rose.) Hydrated tantalic acid is
soluble in solution of caustic potash. Sulpho-tantalic acid while yet
moist likewise dissolves readily and in large quantity in solution of
potash. (Wohler.) The fused compound is opaque when it contains
an excess of tantalic acid; but when the potadi is in excess, it has a
vitreous aspect, and is perfectly soluble in pure water: it does not,
however, dissolve at ordinary temperatures in water containing carbonate
10 TANTALUM.
of potash. AccordiDglj wben tantalio acid is fused with excess of car-
bonate of potash, the greater part of the undecomposed carbonate of
potash may be separated by means of cold water; the residue, after being
washed with cold water, is then dissolved in boiling water and evapo-
rated out of contact of air. A non-crystalline residue remains, having a
slightly metallic and unpleasant taste. From an aqueous solution of the
above salt, all acids, including even the carbonic acid in the air, precipi-
tate tantalic acid. (Berzelius.) From a solution of sulpho-tantalic acid
in caustic potash, ssd ammoniac precipitates the tantalic acid^ though not
completely, in the form of tantalate of ammonia. (Wohler.) IT Tantalic
acid when fused with carbonate of potash, yields a double salt of tantalate
and carbonate of potash; but the solution deposits after some time, or
on evaporation, a large quantity of acid tantalate of potash. Generally,
when tantalic acid is fused with carbonate of potash, and the fused mass
digested in water, the greater part of the acid remains undissolved in the
form of acid tantalate. (Rose.) H
B. Sulphate op Tantalio Acid and Potash. — ^Prepared by fusing
tantalic acid with bisulphate of potash. The compound is decomposed by
water, which leaves hydrated tantalic acid undissolved. (Berzelius.)
C. Fluoride op Tantalum and Potassium.— a. WUh a smaller
proportion of tantalum. Acid hydrofluate of tantalic acid is mixed hot
with potash till a precipitate begins to separate; or a solution of bihydro-
fluate of putash is heated with tantalic acid, — in the latter case, monohy-
drofluate of potash remains dissolved in the liquid. On cooling, tne
compound crystallizes out in anhydrous scales.
Or: Berzelius.
2K 78-4 .... 21-97 2KO 94-4 .... 26*45 .... 2354
Ta 185-0 .... 51-83 TaO* 209*0 .... 58*56 .... 56*99
5P 93-5 .... 26*20 5(F-0) .... 53*5 .... 14*99 .... *
356*9 .... 100-00 356*9 .... 10000
[* The loM, amounting to 19*47» represents, according to Beneliui^ not onlf
hydrofluoric add, but also a portion of siUca.]
The compound is not decomposed by exposure to a white heat in
platinum vessels; nor even by ignition with hydrated bisulphate of potashi
from which only the excess of sulphuric acid is volatilized. With hydrated
sulphuric acid, it evolves hydrofluoric acid. It is decomposed by potas-
sium, with incandescence, yielding tantalum and fluoride of potassium.
Dissolves sparingly, though without residue, in cold water, but much more
readily in hot water. When boiled with water it is decomposed, a white
powder being deposited, which is richer in tantalum than the portion
which remains in solution.
6. With a larger proportion of tantalum, — 1. Formed by adding hydro-
fluoric ai3id to a warm solution of a, before it begins to crystallize: the
acid takes up one-third of the potash to form bihydrofluate of potash.—
2. By supersaturating a solution of tantalate of potash in boiling water
with hydrofluoric acid. The compound crystallizes out on cooling, in
short, slender, anhydrous needles. By analysis, it is found to contain 63
per cent, of tantalic acid, and probably consists of 3 atoms of potassium,
2 atoms of tantalum, and 9 atoms of fluorine. When heated to redness,
either alone or with bisulphate of potash, and also with sulphuric acid, it
behaves like a. It is likewise difficultly soluble in water. (Berzelius.)
IIYDROFLUATE OF TANTALIC ACID AND LIME. 11
Tantalum and Sodium.
A. Tantalatb of Soda. — a. Neutral salt. — Prepared bj fusing tan-
talio acid with hydrate or carbonate of soda. It is soluble only in hot
water^ the greater part again falling to the bottom as the liquid cools. -^
Before the blowpipe^ tantalic acid expels the carbonic acid from carbonate
of soda with effervescence; the resulting tantalate of soda is infusible.
(Berzelius.)
IT Transparent; becomes turbid when heated, in consequence of the
separation of a white acid salt. After ignition, it is insoluble in water.
It remains colourless when ignited in a current of hydrosulphuric acid
gas; but all the soda is converted into double sulphide of hydrogen and
sodium. If a cold solution of tantalate of soda be treated with caustic
soda, and the mixture evaporated at ordinary temperatures over oil of
vitriol) the resulting compound is no longer completely soluble in water.
6. Acid Salt. — 1. The residue left after prolonged fusion of tantalic acid
with excess of carbonate of soda and treatment of the mass with water.
In this operation, the tantalic aoid expels a quantity of oxygen in the
carbonic acid greater than the amount contained in itt>elf, in the propor-
tion of 3 : 4. — 2. Deposited in large quantity on boiling a solution of
neutral tantalate of soda. White; it is decomposed by ignition in a current
of hydrosulphuric acid gas, but remains perfectly colourless. (Rose, Po<7^4
69, 118.) IT
B. With borax, tantalic acid forms a colourless glass, which is rendered
turbid by gentle flaming, and if it contains an excess of tantalic acid,
becomes enamel-white on cooling. (Berzelius.) IT Rose has obtained the
same results with pure tantalic acid from the Finland tantalite. IT
C. In microcosmic salt, tantalic acid dissolves with great difficulty
but in large quantity, yielding a colourless glass which remains transpa-
rent when cold. (Berzelius.) IT Tantalic acid yields a colourless and
transparent glass in both flames: the addition of forrous sulphate does not
impart a red colour to the bead. (Rose.) IT
D. Fluoride op Tantalum and Sodium. — Indistinct crystals, very
soluble in water. (Berzelius.)
Tantalum and Barium.
Tantalate of Bartta. — Hydrated tantalic acid digested with an
aqueous solution of chloride of barium^ to which a small quantity of
ammonia is added, takes up at most 63' 6 parts (rather more than one
atom) of baryta to 209 parts (one atom) of tantalic acid, and is thereby
converted into a white, insoluble powder. (Gahn, Bercelius & Eggertz.)
Tantalum and Calcium.
A. Tantalate op Limb. — Insoluble. (Berzelius.)
B. Hydropluate op Tantalic Acid and Limb. — The aqueous solu-
tion, when evaporated, gives off hydrofluoric acid and deposits a very
insoluble eompoond, containing the same elements but in different propor^
tions. (Belrseuus.)
12 TANTALUM.
Tantalum and Magnesium.
Hydrofluate of Tantalig Acid and Magnesia. — The aqneous
Bolation of this salt is likewise decomposed by evaporation, a very diffi-
cultly soluble compound being deposited. (Berselius.)
Tantalum and Yttrium.
a. Fergusonite.—eiYO; CeO; TbO), TaO*. Crystalline system, the
square prismatic. Specific gravity from 5*8 to 5'B6. Brownish black;
translucent in thin laminie. When heated it evolves a trace of water,
becoming deep yellow at first, and subsequently pale yellow, bnt without
fusing. Dissolves slowly in borax, forming a glass which is yellow while
hot; but if saturated, is rendered turbid by flaming, and acquires a dinsy
yellowish red colour. The mineral dissolves slowly in microcosmic sut,
yielding in the outer flame a yellow, and in the inner flame a colourless
glass, which, when sufliciently saturated, assumes a reddish tint, and in
that case becomes opaque on cooling or after slight flaming. It is decom-
posed by carbonate of soda without being dissolved, and leaves a reddish
slag. (Berzelius.) It is also decomposed by fusion with bisulphate of
potash.
Atoms. HartwaU.
CeO 1 .... 54'0 .... 6-98 .... 4-68
YO 10 .... 4000 .... 44-33 .... 41-91
ZrO 1 .... 30-4 .... 3*37 .... 302
TaO» 2 .... 418'0 .... 46-32 .... 47*75
Fe^O* .... .... .... 0*34
1 ~ 902-4 Z, 100-00 Z. 99*65
h, TUro-tantalite. — «. Brownish black variety, — 4(CaO; YO; UO; FeO),
TaO'. — Translucent and of a pale yellow colour, when in thin laminso.
Decrepitates slightly before the blowpipe, and assumes a light yellow
colour, without fusing. With a large quantity of borax it forms a trans-
parent, yellow ^lass; with a smaller quantity, a dark yellowish brown
glass, it dissolves in a still larger quantity of microcosmic salt — with
separation of a white skeleton, which disappears but very slowly and
yields a glass which is yellow while hot and colourless when cold: if
the quantity of yttro-tantalite is greater, a turbid glass is produced in
the inner flame, pale green while hot, but covered with white, opaque
streaks after cooling. Does not dissolve in carbonate of soda. Contams
5*7 per cent, of water, (Berzelius.)
/3. Black variety.— S{CtiO', YO; FeO), (TaO*; WO').-^pecific gravity
=: 5-395. Scratches glass. Black; opaque; possessed of metallic lustre;
decrepitates slightly before the blowpipe, and becomes dark brown, but
without fusing. With borax it yields a transparent, colourless or
yellowish glass, which, when it contains a comparatively small propor-
tion of the yttro-tantalite, is rendered opaque by flaming; but when it
contains a larger quantity, becomes opaque without flaming. Dissolves
slowly in microcosmic salt with separation of a very insoluble skeleton,
producing a colourless or yellowish glass, which, with a large quantity of
yttro-tantalite in solution, becomes saffron-red and finally opaque in the
mner flame. It swells up with carbonate of soda, and remains in the form
of a white mass after the soda has been absorbed by the charcoal. Con-
TANTALATE OF TTTRIA.
13
tains 5'4 per cent of water. (Berzelius.) ^ Specific gravity = 5*882
(Bkeberg); = 5*67 (Peretz); loses 5-54 per cent, of water by ignition,
after which its specific gravity is 6*40. It contains pare tantalic acid free
from niobic and pelopic acids. (Rose, Fogg. 72, 155.) IT
y. Yellow variety, — The same formula as B. Specific gravity ^ 5*882.
(Ekeberg.) Softer than glass. Brownish yellow and opaque. Decrepi-
tates slightly before the blowpipe, and becomes pale yellow, but does not
fuse. With borax, in the inner flame, it yields a transparent, yellow
glass, which becomes darker yellow on cooling, and is rendered milk-white
by flaming. With microcosm ic salt it behaves in a similar manner to a,
excepting that the saturated bead assumes a fine green colour in the inner
flame, and on cooling becomes pale rose-red and very turbid, owing to
the presence of ferrous tungstate. Contains 4*6 per cent, of water.
(Berzelius.)
All three varieties of yttro-tantalite are insoluble in aqueous acids, but
are completely decomposed by fused bisulphate of potash. According to
Berzelius, the water which they contain does not appear to be essential
to their constitution. The following specimens were analysed after
ignition :
At.
ntrO'tanialite, a.
BerzeliiUr
CaO ....
11
3080
3-18
3-26
YO
.... 95
38000
39-27
38-52
UO
• ••■ X
680
0-71
1 04
FeO
!•••■ A
35-2
0-36
0-49
T»0»
.... 25
52250
54-00
51-82
WO»
<•••• V
-...
2400
2-48
2-59
1
«••«
9676-2
10000
97-72
At.
Vitro^ianialUe, p.
Berzelius.
CaO
>■■»• 4
1120
7-48
6-25
YO
•••• «f
3600
2403
20-25
UO
••••••••••••••4
>■ *■•
0-47
FcO
••••■•••••••■•■
2
70-4
4-69
3-16
T»0»
1 . . .. ^
8360
55-79
57-00
W03
1.... *■
1200
801
8-25
1
1498-4
100-00
95-38
yttrO'tanialiie, y; different flpecimens, 1 and 2.
At.
1.
Berzelius.
CaO
.... 2
560
• • ••
0-57
0-50
YO
.... 75
3000-0
• • t*
30-34
29-78
UO
.... 8
544-0
■ •»•
5-50
6-25
FeO
3
105-6
• •■•
1-07
1-04
TaO»
29
6061
• • ••
61-30
6012
WO>
1
120-0
• « ••
1-22
1-04
1
9886-6
• •■•
100-00
98-73
At.
2.
Berzelius.
Penetz.
CaO
... 10
• ■••
280 ....
2-87
■ •••
3-29
7-55
YO
... 71
.... 2840 ....
29-13
• •••
29-90
21-25
UO
... 4
• • ■•
272 ....
2-79
• •••
2-99
3-94
FcO
... 5
• •••
176 ....
1'81
• •■•
2-44
6-29
TaO»
... 29
6061 ....
62-17
••••
59-50
58-65
WO»
... 1
t •••
120 ....
1-23
• »••
1-25 {■'^{f^^'"^} 2-40
9749
100-00
99-37
• • •• •••
100-08
The tungstic acid in « and y 1 was found by Berzelius to contain
stannic acid, — He obtained the uranium and iron in his analyses as sesqui-
14 TANTALUM.
oxides, bat they are calcnlated as protoxide«.«-The' caleolations do not
quite agree with the analyses; probably from an admixture of foreign
minerals
c. Etixen{te.^Ahoni: 4(CaO j MgO; CeO; LaO; YO; UO), 1 TiO«, 1 TaO»,
the proportion of the bases to the acids being therefore as 2 : 1. — 6peeific
gravity = 4'60, Brownish black, with metallic, waxy lustre. Emits a»
faint light when heated, and gives off water. Infusible before the blow-
pipe. With borax, in the outer flame, it yields a brownish yellow glass,
which, if a sufficient quantity of the mineral is dissolved, retains its
colour on cooling, and siso in the inner flame; by flaming, it is converted
into a yellowish enamel. It dissolves in microcosmic salt, producing in
the outer flame, a yellow glass which becomes colourless on cooling: if,
however, it contains a large quantity of the mineral, it becomes green on
cooling (uranium); after exposure to the inner flame, the green colour
becomes darker and less pure (from admixture of the violet colour of tita-
nium). The mineral is insoluble in hydrochloric acid and aqua-regia, but
is decomposed by fusion with bisulphate of potash. It contains about
2*47 per cent, of lime, 0-29 of magnesia, 2'18 of protoxide of cerium, 96
of oxide of lanthanum, 25 09 of yttria, 6*34 of protoxide of uranium, 7'94
of titanic acid, 4966 of tantalic acid, and 3*97 of water (loss I'lO). (Th.
Scheerer, JPogg. 50, 1 49.)
Tantalum and Thorinum.
Pyrochlore:— About : 2(2[CaO ; CeO; YO ; ThO ; MnO ; FeO], TaO») +
NaF. Occurs in regular octohedrons, without any plane of cleavage.
Sp. gr. from 4*2.06 to 4-326. Harder than felspar. Dark reddish brown;
translucent at the edges, the transmitted light exhibiting a brown colour.
When heated, it emits a faint light, and evolves water containing
hydrofluoric acid. Before the blowpipe it assumes a pale, brownish-
yellow colour, and fuses with great difficulty, yielding a black slag.
With borax in the outer flame, it forms a clear, reddish-yellow glass,
which. by flaming is readily converted into a yellow enamel; or if a large
quantity of the mineral is held in solution, into a white enamel. With
borax in the inner flame, it forms a dark red glass, which is converted by
flaming into a light greyish-blue enamel. Dissolves in microcosmic salt,
with slight efl*erve8cence, yielding a glass, which, if the outer flame is
oscfl, is yellow while hot and grass-green when cold, but in the inner
flame, becomes dingy green at first and then violet-red. ^The pyrochlore
of Fredrikswam and Brevig behaves in this manner; tnat from Miask
does not give the uranium reaction.) The mineral is decomposed by long
digestion with oil of vitriol at high temperatures. The pyrochJore of
Min.'^k contains: lime 10*98; magnesia a trace; sesquioxide of cerium
(probably protoxide in the mineral itself) with thorina 13*15; yttria 0*8i;
protq;cide of manganese 0*15; protoxide of iron 1*29; tantalic acid 67*38;
titanic and stannic acids, a trace; water 1*16 per cent The pyrochlore
of Brevig contains nearly 5 per cent, of sesquioxide of uranium and 7
per cent, of water. (Wohler, Fogg. 7. 417; 48, 83.)
Tantalum and Alujiixum.
Tantal\te of Alumina. — Insoluble in water. (Berzelius.)
Other Compounds op Tantalum,
With Manganeie and with Iron.
15
IT Chapter XVII. (a.)
NIOBIUM.
H. Rose, Pogg, 63, 317; 69, 118; also N, Ann, Chim. Phys. 13, 350; 19,
165. Further, Fogg. 70, 572; 71, 157; 72, 155 and 471; 73, 455;
74, 288.
Th. Scheerer, Fogg. 72, 561
Hittory. — ^Wollajston {Schw. 6, 256; 21, 60), very soon after the
discovery of tantalum, observed that the tan tali te from America, and the
tantalite from Finland, though to all appearance nearlv the same in com-
{position, were nevertheless of different densities. Thomson, in 1836,
ikewise examined a mineral containing tantalum, found at Middleton in
Connecticut, and from its very low specific gravity, was induced to give
it a new name, Torrelite. Other specimens, varying in density, were also
analysed by Ekeberg&Berzelius, one of which, in consequence of the large
quantity of iron which it contained, received the name of Ferro-tantalite.
ij. pr, Gkem, 13, 217; Fogg, 53.) The different densities of tantalites
rom different localities, and of the acid obtained from them, ^as likewise
the first remarkable circumstance that induced Rose to enter upon a closer
examination of tantalum and its compounds. Thus, it was found that
black tantalite from Bodenmais has a density of 6*39, and the tantalic
acid obtained from it, 6*542; reddish brown tantalite from the same
locality has a density of 5*6996, the acid 5*605; tantalite of the same
colour from North America, 5*708, the acid 5*452. In consequence of
these facts, Rose examined more minutely into the nature of the so-called
tantalic acid; and from the behaviour of the chloride, arrived at the
conclusion that it contained a new metal, which he called Niobium;
subsequently he found in it another new metal, to which he gave the
name of Pelopium.
Sources, — In conjunction with tantalum, in the various minerals which
contain that metal; but more especially in the tantalite from Bodenmais
in Bavaria, which contains niobic acid with a considerable quantity
of pelopic acid; the tantalite from Massachusuets, North America, which
chiefiy contains niobic acid; and the tantalite from the llmengebirg in
Siberia, which contains niobic acid with mere traces of pelopic acid.
Scheerer has lately found niobic acid in Pyrochlore, and variable quan-
tities of the two acids in Eukolite or'Wohlerite, a mineral containing
silica and zirconia; in Euxenite; and in a variety of Pitchblende, found
in the valley of Satersdalen.
Freparation. — Niobium is reduced to the metallic state by passing
a current of dry ammoniacal gas over the chloride. The reduction is
attended with rise of temperature and evolution of hydrochloric acid gas.
16 NIOBIUM.
The redaction of niobiam takes place' at a lower temperature than that
of tantalum.
Properties, — Black powder, which is carried through the filter by pure
water: this inconvenience may, however, be prevented by the addition
of alcohol. When heated in the air, it is converted into niobic acid.
Kitric acid and aqua-regia have no effect upon it; but a mixture of
hydrofluoric and nitric acid attacks it at ordinary temperatures. If we
assume that the composition of niobic acid is analogous to that of tantalic
acid, the atomic weight of niobium will be greater than that of tantalum.
Compounds of Niobium,
Niobium and Oxygen.
Niobic Acid. NiO'?
Preparation, — The acid prepared from Bavarian tan tali te is mixed
with charcoal and heated in a current of chlorine gas. By this treatment
it is converted into a yellow, very fusible, and volatile chloride, and a
whit^ chloride which is infusible and but slightly volatile. The two
chlorides when immersed in separate portions of water, are converted into
oxygen-acids and hydrochloric acid. The hydrochloric acid is then
removed by boiling the mixture and washing the insoluble residues
with water. The acid obtained from the infusible white chloride is again
mixed with charcoal and exposed to a current of chlorine, and the white
chloride obtained, kept distinct as before from the volatile yellow chlo-
ride ; the latter decreases in quantity on each repetition of the process.
Nevertheless, Rose did not succeed in obtaining a perfectly colourless
chloride entirely free from the yellow compound, even after repeating
the above operation a great number of times. The white chloride itself,
however, is partially volatile, and on freeing it by sublimation, first from
the yellow chloride, and afterwards from the non-volatile white portion,
and then digesting in water as above, an acid is obtained, which yields
an almost colourless and perfectly volatile chloride. This is the Chloride
of Niobium, The fixed white residue appears to be a compound of the
chloride with the oxygen-acid of the other metal; for, if mixed with
charcoal and treated with chlorine, it yields a large quantity of yellow
chloride with a small residue of the white compound ; and if this com-
pound is again submitted to the same process, it yields similar results,
till at last little or no residue remains. Rose has observed similar pheno-
mena on treating the pure tantalic acid obtained from the tantaJite of
Finland with charcoal and chlorine ; and finds that the formation of the
fixed white compound may, in this case, be entirely prevented by exclud-
ing air and moisture. Chloride of tungsten, under the same circum-
stances, likewise yields a fixed white residue, which is resolved by heat
into red chloride of tungsten and tungstic acid.
The acid obtained from the yellow chloride of the mineral from
Bodenmais, Rose calls Pelopic Acid, and the metal itself Pelopium, (See
next Chapter.)
Properties. — Colourless, both in the hydrated and anhydrous state:
the hydrated acid, like tantalic acid, becomes incandescent during its
transition into the anhydrous state. When heated, it acquires a yellow
colour, much deeper than that of tantalic acid under the same circum-
stances: on cooling, it again becomes colourless. After ignition, it appears
in fragments having a high degree of lustre, whereas tantalic acid forms
NIOBIC ACID. 17
a dull powder. When ignited in a current of ammoniacal gtLB, it tarns
black, and yields a large quantity of water: in a current of hydrosulphu-
ric acid^ it is slowly converted into sulphide of niobium. The specific
gravity of niobic acid is considerably lower than that of tantalic acid, and
moreover is subject to the same remarkable variations, and from the same
causes : e. g., specific gravity of the amorphous acid, prepared by decom-
posing the chloride with water, after it had been exposed to the air for a
considerable time, and igniting over a spirit lamp; (1) =: 5-12; (2) =
4*977; after exposure to the intense heat of a charcoal fire, (1) = 4*5612;
(2) = 4*562 at 20°; in the porcelain-furnace, the acid was converted into
a loosely coherent mass, easily reduced to a sandy powder, and in this
state had a specific gravity Ci) = 4*6; (2) = 4*602 at 20°; specific
gravity of niobi^c acid prepared troni the chloride without previous expo-
sure to the air = 5*257; after exposure to a charcoal fire for four hours,
4*581 at 20°; after ignition in a porcelain-furnace, 4*589 at 15®; specific
gravity of niobic acid obtained from North American Columbite = 5*259
at 10°; after ignition in the porcelain-furnace and subsequent pulveriza-
tion, the powder had a specific gravity of 4*601; niobic acid from the
Samarskite of Siberia = 5*262 at 13°; after heatiug in a porcelain-fur-
nace, 4*626 at 12°. Amorphous niobic acid varies in density between
5*2545 and 5*2620, the crystalline acid between 4*664 and 4*7633. The
mean densities of the two varieties are to one another as 1 *. 0*875. Niobic
acid is insoluble in all reagents after ignition.
Combinations.'^a. With Water. — Niobic acid is thrown down from its
alkaline solutious by acids, — ^but most completely by sulphuric acid, even
at ordinary temperatures — in the form of white hydrate.
6. With Acids. Hydrated niobic acid is sparingly soluble in hydro-
chloric acid, so that when an alkaline solution of niobic acid is precipi-
tated by a large excess of hydrochloric acid, the filtrate retains traces of
the acid in solution. Niobic acid is soluble to a certain extent in oxalic
acid, and probably also in hydrofluoric acid. The ignited acid likewise
dissolves in fused bisulphate of potash or ammonia, forming a mobile
liquid, which in the former case becomes crystalline on cooling, and in
the latter — provided the sulphuric is in excess — forms a clear, thick syrup.
c. With Salifiable Bases. — Niobic acid expels carbonic acid from car-
bonate of soda when fused with it; and it is remarkable that the quantity
of oxygen expelled from the carbonic acid is more than double of that
which IS contained in the niobic acid itself. The resulting salt is more
fusible than the corresponding tantalate. Niobic acid, like tantalic acid
and pelopic acid, is remarkable for forming, when fused with alkaline car-
bonates, acid salts, which are more or less insoluble in water, but dissolve
in solution of potash or carbonate of potash; but if the fusion be suffi-
ciently prolone:ed, the resulting salt is completely soluble in pure water,
which is not the case either with tantalic or pelopic acid.
AUcaUne Niobiaies are soluble in water, m solution of potash, and in
carbonate of potash, but dissolve with great difficulty in excess of soda
and carbonate of soda; niobiate of soda indeed is much less soluble in
these reagents even than tantalate of soda. Niobic acid is precipitated
from its alkaline compounds by acids, especially by sulphuric acia, even
at ordinary temperatures — unlike tantalic acid, which requires the aid of
beat. Oxalic acid does not affect alkaline niobiates; but acetic acid,
chloride of ammonium, and a current of carbonic acid gas, produce a
precipitate — soluble in the latter case in a large quantity of water.
VOL. IV. c
18 NIOBIUM.
Niobiate of soda acidulated with Bulphuric or hydrochloric acid, and
treated with infusion of galls, deposits a deep orange-red precipitate, some-
what like that formed by titanic acid. This precipitate is soluble in
alkalis, and is not produced in the presence of fixed organic acids. Fer-
rocyanide of potassium, added to a solution of niobiate of soda acidulated
with sulphuric acid, forms a deep red precipitate somewhat like that
thrown down from an acid solution of niobic acid itself by solution of
galls. The precipitate is slightly soluble in a large excess of hydrochloric
acid. Ferricyanide of potassium gives a bright yellow precipitate with
niobiate of soda. If a solution of the same salt be mixed wiih sulphuric
or hydrochloric acid, and a piece of zinc immersed in it, a precipitate is
obtained having a beautiful blue colour; the more acid the solution, the
more rapidly is the precipitate deposited. After a while, however, the
blue colour becomes dingy, and finally brown.
Niobium and Sulphur.
A. Sulphide op Niobium. — Formed by decomposing chloride of nio-
bium or niobiate of soda by a current of dry hydrosulphuric acid gas with
the aid of heat. Crystalline j black; decomposed by chlorine at ordinary
temperatures.
B. Basic Sulphate of Niobic Acid. — When niobic acid is fused with
bisulphate of potash or ammonia, the niobic acid obtained from the fused
mass is intimately combined with a portion of sulphuric acid: to free it
from this, it is necessary to wash the niobic acid, first with pure water
and then with water containing ammonia.
Niobium and Chlorine.
Chloride of Niobium. — This compound is formed at a lower tem-
perature than chloride of tantalum or chloride of pelopium, though it is
less volatile than either; hence it is more easily reduced, whether alone
or in combination. It dissolves completely in sulphuric acid with the aid
of a gentle heat : the solution is not rendered cloudy by boiling; but if
diluted with water and then boiled, it becomes turbid, and ultimately
deposits the whole of the niobium in the form of niobic acid. When
treated with hydrochloric acid, it neither dissolves nor forms a jelly; and
the addition of water does not produce any chance. Dilute hydrochloric
acid behaves in the same manner; but, on the addition of water, a clear
solution is obtained, which does not deposit niobic acid on boiling, but is
rendered turbid by sulphuric acid at ordinary temperatures. It is com-
pletely decomposed by a large quantity of boiling water; a milky liquid
being formed, from which niobic acid is precipitated in flakes by boiling.
Caustic potash dissolves it completely, so likewise does a boiliuff solution
of carbonate of potash. Hydrosulphuric acid does not attack it at ordi-
nary temperatures, but readily converts it into sulphide of niobium, when
aided by heat
Niobium and Potassium.
Niobiate op Potash and Carbonate of Potash. — On fusing niobic
acid with carbonate of potash, a double salt of niobiate and carbonate of
potash is formed, from which the carbonate may be separated by keeping
the temperature low, and arresting the process before the whole of the
carbonic acid is expelled. On digesting in water, an insoluble acid salt
of potash is obtained. The latter is soluble in solution of potash.
NIOBIUM AND YTTRIUM. 19
Niobium and Sodium.
NiOBiATE OF Soda.— a. MononiobicUe. — Niobic acid when fused with
soda forms a compound which is soluble in water, especially at a boiling
heat. The solution is not decomposed either by continued boiling or
by slow evaporation. The salt may be rendered anhydrous without
losing its solubility. A strong solution of niobiate of soda gives a crystal-
line precipitate with caustic soda and carbonate of soda. The salt is
decomposed at a red heat by hydrosulphuric acid gas, the product being
a black mass, which is resolved by water into sulphide of hydrogen and
sodium, and insoluble sulphide of niobium.
b. Add Niobiate of Soda, — Obtained like the acid niobiate of potash.
c. With borax, niobic acid yields a colourless bead, which^ if the acid
is in sufficient quantity, becomes opaque on flaming. In the inner
flame, the bead assumes a greyish blue colour, provided it contains a
sufficient quantity of acid to produce opacity on cooling.
d. Niobic acid dissolves in large quantity in microcosmic salt, and
forms a colourless bead in the outer flame; in the inner flame, a violet-
colour is produced; and if the bead be saturated with the acid, it assumes
a beautiful blue colour. The colour disappears in the outer flame; the
addition of ferrous sulphate changes the blue colour to blood-red. When
mixed with tungstic acid — e. g,, as obtained from Samarskite — it imparts
both to borax and microcosmic salt a yellow colour which disappears on
cooling.
Niobium and Yttrium.
Samarskite, — This mineral, first named Urano-tantalite or Columbite,
and afterwards called Tttro-Umenite by Hermann, and Samarskite by
Rose, is found in the Ilmengebirg in Siberia. Specific gravity = 5*617
(H. Rose); 5-6142 (Womam); specific gravity of Yttro-ilmenite = 5*398
....5*45 (Hermann). Fracture conchoidal, with a high lustre, almost metal-
lic. Decrepitates when heated, exhibiting vivid incandescence, and is
afterwards perfectly insoluble in hydrochloric acid. Does not change
colour when heated in a close vessel; in contact with air it acquires a
brownish colour on the outside. (Pogg. 72, 47 1 .) The metallic acid obtained
from this mineral consists almost wholly of niobic acid, with small quan-
tities of tungstic acid and pelopic acid: hence niobic acid may be obtained
from it in a state of greater purity than from the columbites of Bodenmais
and North America.
Penetz.
Ck}lumbite. Samarskiie. YttrO'iimenite.
From Siberia.
1. 2.
CaO
0-76
MgO
3*01
PeO
12*76
MnO
TO
} 4*48
XJ»0»
0*56
CuO
-01
TiO»
HO
NiO»
78*59
2*08
0-76 2'44
15*94 8*06 8*50
+ CaO / 1*88 MnO 1*00 6*09
1 8*36 19*74 2-00
16*77 UO 5*64 050
1*50
1*66
55*91 61*33 +WO» 80*47
100*17 99-61 101*01 10000
c 2
20 PBLOPIUM.
The large qaantity of magnesia found in the Siberian columbite dietin-
gnishes it from all other tantalites. Yttro-ilmenite (included bj Rose
under the name of Samarskite) was examined by Hermann, and supposed
bj him to contain the acid of a new metal, llinenium. This acid, how-
eyer^ has been proved by Rose to consist of niobic acid mixed with a small
quantity of tungstic acid, to which are owing the peculiarities that induced
Hermann to suppose the existence of a new and distinct metal. ( Vid,
Fogg, 73, 455.)
n CnAPTEB XVII. (b.)
PELOPIUM.
H. Rose. Pogg. 63, 377, &c., &c.
History, Qiven in connection with that of niobium.
Sources, As pelopic acid, more or less mixed with niobic acid, in the
tantalites of Bavaria and of North America, but more especially in the
former.
Preparation^ Similar to that of niobium^ by passing a current of dry
ammoniacal gas over chloride of pelopium. This salt requires greater
heat for its reduction than chloride of niobium.
Properties, Black powder, resembling metallic tantalum in appear-
ance. This resemblance between pelopium and tantalum runs through
all their compounds, so that they are very difficult to distinguish; and
when they occur together, cannot be separated by any known method.
The atomic weight of pelopium has not yet been determined.
Compounds of Pelopium,
Pelopium and Oxygbn.
Pelopic Acid. PeO'?
Preparation, The more volatile yellow chloride obtained from Bava-
rian tantalite in the preparation of niobic acid, is similarly treated with
water, and the resulting acid washed, dried, and ignited over a spirit-
lamp.
Properties, Resembles tantalic acid very closely in all its properties.
Colourless at ordinary temperatures. When ignited, it acquires a yellow
colour intermediate in depth between that of tantalic and that of niobic
acid; becomes colourless again on cooling. Like niobic acid, it is dark-
ened by a current of hydrogen at a red heat, though not so strongly;
PELOPIC ACID. 21
whon ignited in the air it again becomes white. A current of dry ammo-
niacal gas likewise blackens it at a red Leat^ a large quantity of water
being formed at the same time. When ignited in a current of hydrosul-
phuric acid gas, it is slowly conyerted into sulphide of pelopinm. Pelopic
acid, like tantalic and niobic acid, varies in density according to the
temperature at which it has been ignited : thus, the density of pelopic
acid prepared from the chloride and ignited over a spirit-lamp, was
found to be (1) = 5-98; (2) = 5-982 at 20°; after exposure to a strong
charcoal fire for six hours, and reduction of the semi-fused mass to pow-
der in an agate mortar, the specific gravity of the powder was (1) =
6'd61; (2) 6'370 at 20*^; after ignition in a porcelain furnace and reduc-
tion to powder as before — the powder under the microscope having a
crystalline appearance— the specific gravity was: (1^ and (2) = 5-793 at
22"^. The acid, after exposure to the heat of the porcelain furnace, re-fusion
in bisulphate of potash — in which, under these circumstances, it dissolves
with great difficulty, — washing with a large quantity of hot water, and then
with water containing ammonia^ till the filtered liquid no longer rendered
baryta salts turbid, appeared very bulky, and had a specific gravity of
(1) 6-140; (2) 6-146, after heating in a charcoal fire; (1) and (2) =
6 '4825; and lastly, after re-exposure to the porcelain furnace, whereby it
became caked together, and exhibited the same properties as before, its
density was reduced to 5*830. Pelopic acid prepared from chloride of pelo-
pium which had not been exposed to the air, and having an amorphous
appearance under the microscope, had a specific gravity of 6-236 at 15°;
alter heating in a charcoal fire for one hour, its density was increased to
6-416; and after exposure for three hours lonjrer, to 6*725, the acid still
retaining its amorphous state. A portion of acid prepared from the chloride
after exposure to the air for two months, decrepitated strongly and became
incandescent when heated — appeared crystalline under the microscope —
and had a specific gravity of 6*239, or nearly the same as the amorphous
acid. Pelopic acid obtained by the decomposition of the acid chloride, and
found in the tube used in the preparation of chloride of pelopium, had the
lowest specific gravity yet found, viz., 5-495 at 15°; and after exposure for
an hour to a charcoal fire, 5' 566; this acid appeared under the microscope
to consist of distinct acicnlar crystals. Pelopic acid from North American
Columbite, prepared from the chloride, had a specific gravity of 6*098; and
after ignition m a porcelain furnace — ^whereby it became caked together,
and appeared under the microscope to consist of large crystals — the specific
gravity was increased to 6*17. From these results. Rose concludes that
pelopic acid is susceptible of three modifications : (1) amorphous; (2) crys-
talline before ignition; (3) cr3rsta]line after ignition in the porcelain-
furnace. The specific gravity of (1) and (2) varies according to the mode
of their preparation; that of ^3) is constant. The range of specific gravity
for pelopic acid appears to oe between 5*495 and 6*725. From this it
will be seen that its density is intermediate between that of tantalic and
that of niobic acid. It is insoluble in all reagents after ignition, unless
previously fused with bisulphate of potash (or lukaline carbonates ?).
Of the three acids, niobic is the strongest and most easily reduced,
tantalic acid the weakest and least easily reduced to the metallic state,
pelopic acid occupying the intermediate position.
CoTnbinations, — a. With water. Obtained in the same manner as
hydrated tantalic and niobic acid. Sulphuric acid precipitates, it less
completely than nrobie acid. White; amorphous.
22 PELOPIUM.
b. With Acids. Hydrated pelopic acid ia more soluble in hydrocbloric
acid than niobic acid; the solution appears opalescent, and is completely
precipitated by boiling with sulphuric acid. Pelopic acid likewise dis-
solves in fused bisulphate of potash: the mass does not appear crystalline
on cooling, as in the case of niobic acid.
c. With Salifiable Bases. Pelopic acid, like tantalic and niobic acid»
when fused with excess of carbonate of soda, expels a quantity of carbonic
acid much larger than that which corresponds to its own amount of
oxygen. It likewise forms acid salts by fusion with alkaline carbonates;
but the quantity of acid pelopiate produced is smaller than the quantity
of acid tantalate formed by the action of tantalic acid on alkaline carbo-
nates. These acid salts are insoluble in water, but dissolve in excess of
potash or carbonate of potash.
Alkaline Pelopiatet are soluble in water, and likewise in potash or its
carbonate, but are precipitated from a strong solution by soda and carbo-
nate of soda. They are precipitated by the same reagents as niobic
acid (p. 17). When acidulated with sulphuric or hydrochloric acid,
they yield an orange-yellow precipitate with tincture of gall% and a
brownish-red precipitate with ferrocyanide of potassium. Alkaline pelo-
piates, when mixed with a large excess of hydrochloric acid, are pre-
cipitated at first, and the precipitate afterwards redissolved, an opalescent
solution being obtained, whicn, unlike tantalic acid, is completely preci-
pitated by sulphnric acid at a boiling heat. A neutral solution of pelo-
piate of soda does not become turbid on exposure to the air (a peculiarity
which serves to distinguish pelopic from tantalic acid). When a piece of
zinc is immersed in the solution of an alkaline pelopiate strongly acidu-
lated with hydrochloric acid, the precipitated acid does not assume a blue
colour, but only appears a little less white or slightly grey : on adding
sulphuric acid, however, it acquires a pure blue colour, which, after some
time, grows dull, but does not change to brown. A beautiful blue colour
is obtained by treating chloride of pelopium with hydrochloric acid,
diluting with water, and adding a piece of cine.
Pelopium and Sulphur.
A. Sulphide of PELOPiUM.-^-Obtained in a similar manner to the sul-
phide of niobium; but the decomposition is effected at ordinary tempera-
tures. Black. Not attacked by chlorine at ordinary temperatures, but
decomposed on the application of heat.
B. Basic Sulphate of Pelopic Acid. — Formed under the same cir-
cumstances as the corresponding niobium compound. Decomposed likewise
by prolonged washing, especially with water containing ammonia.
Pelopium and Chlorine.
Chloride of Pelopium. — Produced at a lower temperaturo than
chloride of tantalum. Chloride of pelopium has a great tendency to
combine with pelopic acid; and in preparing it from pelopic acid, char-
coal, <kc. (p. 16), it is necessary to place a layer of pure charcoal beyond
the mixture to prevent this combination. Chloride of pelopium volatUiees
at 125"" and fuses at 212° C; hence, like chloride of tantalum, it begins to
PELOPIATE OF SODA. 23
Tolatilize before fiusion. The pore salt forms a clear yellow liquid, which
solidifies more slowly than fused chloride of tantalum. It dissolyes in
sulphuric acid, forming a solution which is similar in its properties to
that obtained with chloride of tantalum, excepting that the jelly formed
on boiling is less dense. It likewise dissolves in hydrochloric acid at
ordinary temperatures; but if it be treated with boiling hydrochloric acid,
and the mixture when cold diluted with water, a clear solution is obtained,
which is not precipitated by boiling or by sulphuric acid at ordinary
temperatures. It is decomposed by boiling water; but the resulting acid
is not of a floculent appearance, and is very difficult to collect on a filter.
It is much more soluble both in caustic potash and its carbonate, than
chloride of tantalum. It is blackened and decomposed by hydrosulphuric
acid at ordinary temperatures.
Pelopium amj> Potassium.
Acid Pelopiatb of Potash. — By fusing pelopic acid with carbonate
of potash, and treating the residue with water, an insoluble acid salt is
obtained, though in much smaller quantity than in the case of tantalio
acid. The salt is soluble in solution of potash.
Pelopium and Sodium.
Pelopiatb of Soda. — a. NeiUral salt. When pelopic acid is fused
with excess of carbonate of soda, and the fused mass treated with water, the
solution — as in the case of the other two acids — does not contain a trace
of pelopic acid; but on again adding a large quantity of water, an opales-
cent solution is formed, less turbid than with tantalate of soda. Pelopiate
of soda is less stable than the corresponding salt of niobio acid; for on
boiling its aqueous solution, a white precipitate is formed — less consider-
able, however, than with tantalate of soda. When a cold solution of this
salt is treated with caustic soda, and the mixture evaporated over oil of
vitriol, a mass is obtained which does not again dissolve completely in
boiling water; but this character is not so well marked as with the tanta-
late of soda. A strong solution of pelopiate of soda is precipitated by
caustic soda or carbonate of soda; and if the mixture be slowly and care-
fully made, the salt is obtained in the crystalline state, though the crys-
tals are less distinct than in the corresponding niobium compound. It is
decomposed by hydrosulphuric acid in a similar manner to niobiate of soda.
6. Acid Salt, — Obtained in a similar manner to the acid salt of potash,
and likewise by boiling a solution of the pelopiate. It is decomposed by
a current of hydrosulphuric acid at a red heat, the mass becoming black
in consequence of the formation of sulphide of pelopium; on cooling, the
decomposed mass exhibits a deep brown oolonr.
c. With borax, pelopic acid behaves in a precisely similar manner to
tantalic acid.
d, Microcosmic salt dissolves pelopic acid in large quantity, forming
a colourless bead in the outer flame. In the inner flame, the bead assumes
a clear brown colour slightly tinged with violet; in the oxidizing flame,
the colour disappears again after some time. If sulphate of ferrous
oxide is added to the brown bead, it assumes a crimson colour.
A mixture of niobic and pelopic acids — as obtained, for instance, from
the tantalite of Bodenmais — ^ffenerally communicates a brown colour to
microcosmic salt in the inner flame. IT
24
Chapter XVII I.
TUNGSTEN
Scbeele: Opuse. 2, 119.
De Lujart (The brothers). Chemische Zergliederung de$ Wolframs^ Ac.
translated by Gren. HaUe^ 1786.
Klaproth. BeUrdgCy 3, 44.
Vaaqaelin & Hecbt. Joum. des Mines, 19, 3.
Ricbter. Ueher die neuem Gegenttdnde der Chemie, I, 45; 10, 148.
Bncholz. Schw. 3, 1.
Berzelins. Schw. 16, 476. — Also Ann, Chim. Phys. 17, 13. — Also Pogg.
4, 147; 8, 267.
Wobler. Pogg. 2, 345.
Makguti. Ann. Chim. Phy$. 60, 271; also J. pr. Chem, 8, 179.
Antbon. J. pr. Chem. 8, 399; 9, 6, 8, & 337.
Margaeritt^. J. Pharm, 3, 7, 222.
Wolfram, TungsUne, Scheel, Scheelium, Wolframium.
History. Tungstio acid wns disoovered by Scbeele, in 1781; metallic
tungsten was first obtained from it by tbe brotbers De Luyart. Its com-
binations were principally examined by Berselios.
Sources. As tnngstic acid and some of its salts in Tangstite, tungstate
of lead, and Wolfram (unless the latter contains suboxide of tungsten),
and in small quantities in Yttro-tantalite.
Preparation. 1. By exposing tungstic acid mixed with powdered
charcoal in a covered crucible to the strongest heat of a powerful blast
furnace (De Luyart); or by strongly igniting tungstate of ammonia in a
charcoal crucible. (Bucholz.) The metal is rarely- obtained in large
grains. — 2. Hydrogen gas is passed oyer ignited tungstic acid containing
potash as long as oxygen given off, and the reduced metal is boiled with
solution of potasb, wbich dissolves out the adhering tungstate of potash.
(Wohler.^--3. At a strong red heat, pure tnngstic acid may likewise be
reduced oy hydrogen gas. (Berselius.) — 4. With carbonate of soda on
charcoal, tnngstic acid may also be easily reduced in the inner blowpipe
flame. (Berzelius.) — 5. Children succeeded in reducing tungstic acid by
means of bis voltaic batteiy. — 6. Clarke obtained nrom tungstic acid,
before tbe oxy-hydrogen blowpipe flame, a copper-coloured (?) metal.
TUNGSTIC ACID. 25
Properties. The metal, as obtained by the first method, is steel-grey,
and has a rather powerful metallic lustre; its specific gravity is 17*22
(Allen & Aiken), 17-4 rBucholz), 176 (De Luyart). It is very hard,
being scarcely scratched oy a file; brittle; barely fusible in a blast-furnace
— less readily even than manganese. It is not magnetic. — The metal pre-
pared by the second method is a tin-white, heavy powder : that obtained
by the third and fourth methods is a steel-grey, heavy metallic powder ;
and that obtained by the fifth method is greyish white, brilliant, and
very brittle.
Cvmpownde of Tungsten.
TUNOSTBN AND OxTOEN.
A. TuNGSTous Oxide. Brown Oxide of Tungsten. WO*.
Preparation. 1 . Hydrogen gas is passed over tungstic acid free from
potash, and feebly ignited in a dass tube. (Berzelius.) — 2. Tungstic acid
IS heated to redness with a small quantity of finely divided charcoal in a
covered crucible. (Bucholz, Wbhler.) — 3. A mixture of tungstate of
potash with excess of sal-ammoniac, obtained by evaporating the mixed
aqueous solutions of the salts to dryness, is fused in an earthen crucible till
the whole of the sal-ammoniac is expelled; the chloride of potassium is then
removed by water; the acid tungstate of potash which remains undecom-
posed dissolved out by a boiling dilute solution of potash, and the residue
well washed with water. (Wbhler.) — 4. Dilute hydrochloric acid is made
to act on a mixture of tungstic acid and zinc — the zinc and hydrochloric
acid being renewed till the whole of the tungstic acid is converted into
copper-coloured scales. These scales are then purified with water, out of
contact of air, and preserved under water. (Wbhler.)— 5. Bichloride of
tungsten is decomposed by water. (Wbhler.)
Properties. The oxide preparea by the first and second methods is a
brown powder, leaving a dark copper-coloured streak; that obtained by
the third method is a jet-black powder, which, under the burnishing
steel, becomes ffrey and assumes tne metallic lustre; the fourth method
yields the oxide m copper-coloured laminsa, having a metallic lustre;
the oxide prepared by the fifth method is violet-brown. Sp. gr. = 1 2 * 11 09.
(Karsten.)
CftlGiiIation aooording to Berzelius.
W 96 .... 85-7
20 16 .... 14-3
WO» 112 .... 100-0
Decompo9iti<m. By strong ignition in a current of hydrogen gas (and
if potash is present, even at a lower temperature), this oxide is resolved
into metallic tungsten and water; by ignition with dry carbonate of soda
out of contact of air, into tungsten and tungstate of soda. (Wbhler.)
B. Tungstic Oxide. Blub Oxide of Tungsten.
Formed by the action of various deoxidizing agents on tungstic acid. —
1. By igniting tungstate of ammonia in a covered crucible. According
to Malaguti, a variable quantity of tungstic acid remains mixed with the
26 TUNGSTEN.
blue oxide. — 2. By passing hydrogen gas oyer tnn^stic acid heated in a
glass tube by a spirit-lamp, as long as water continues to be giyen off.
The tungstic acid thus treated loses 3*054 per cent, of oxygen. (Malaguti.)
According to Malaguti, the brown oxide is neyer produced at the compara-
tively low temperature of the spirit-lamp, as long as the stream of hydrogen
is kept up ; this statement, however, is opposed to that of Berzelius. —
8. Carbonic oxide reduces tnngstic acid at a red heat to blue oxide.
(Gobel; Gmelin.)
Blackish indigo-blue; opaque.
Calculation, according to Malagnti.
2W 192 .... 82-76
50 40 .... 17-24
W^O* = WO«,W0» 232 Z. 10000
C. Tungstic Acid. WO'.
ScheeUaure, Wolframsdure, Acide iungstique. — Found native.
Formation, 1. Tun^ten does not oxidise in the air at ordinary tem-
peratures; but at a red heat it takes fire, and, if in a state of powder,
bums like tinder, producing tungstic acid. Under these circumstances
100 parts of tungsten absorb 24 parts of oxygen. (De Luyart.) Nitric
acid and aqua-regia oxidize tungsten and convert it into tungstic acid.
Water, hydrochloric acid, and sulphuric acid do not act on the metal.
(De Luyart.) — 2. The brown oxide prepared by either of the first three
methods remains unchanged in the air at ordinaiy temperatures, but
bums like tinder when heated, and forms tungstic acid (Berzelius,
Wohler); that prepared by the fourth method oxidizes rapidly in the air
even at ordinanr temperatures, first yielding blue oxide and then yellow
tungstic acid. (Wohler.) The brown oxide likewise dissolves in a boiling
concentrated solution of potash, evolving hydrogen gas and forming
tungstate of potash. (Berzelius.) — 3. The blue oxide remains unaltered
in the air at ordinary temperatures, but gradually absorbs oxygen at a
red heat (3*15 per cent., according to Malaguti), by which its blue colour
is first changed into green and lastly into the characteristic yellow colour
of tungstic acid. It dissolves very slowly in aqueous solutions of the
alkalis, after being first converted into tungstic acid by the addition of
oxygen derived from the water. (Berzelius.)
Preparation, 1. Finely-pounded wolfram is digested for a long time
with rather strong hydrochloric acid — the mixture frequently shaken — ^the
acid renewed*— ^nd a portion of nitric acid added towards the end of the
process to convert the protoxide of iron still combined with the tungstic
acid into sesquioxide, and dissolve it. This process is continued till the
acid has removed the whole of the sesquioxides of iron and manganese,
and the brown powder is for the most part changed to yellow. The
insoluble portion, consisting of tungstic acid, undecomposed wolfram,
and quartz, after being well washed, is then shaken up with solution of
ammonia, which dissolves the liberated tungstic acid. The crystals of
tungstate of ammonia obtained by evaporating the filtered solution, are
converted into tungstic acid by ignition in the air. — 2. Richter fuses one
part of powdered wolfram with 4 parts of nitre (Bucholz uses 2 parts of
carbonate of potash); exhausts the mass with water; precipitates tung-
state of lime from the filtrate containing tungstate of potash, by adding
TUNGSTIC ACID. 2?
chloride of calcinm; and decomposes the lime-salt, after washing, with
nitric acid. The tuogstio acid is then separated in the form of powder,
and is parified from nitrate of lime bj washing with water. — The tung-
state of lime must be mixed with a small quantity of water and treated
with a large excess of boiling and moderately dilute sulphuric, hydrochlo-
ric, or nitric acid (3 parts of water to one of oil of vitriol), — ^boiled for a
quarter of an hour — and the tungstic acid washed till the solution begins
to pass turbid through the filter. Or the boiling solution of tungstate of
potash may be supersaturated with hydrochloric acid; the mixture boiled
for a quarter of an hour; the precipitated tungstic acid washed, dried,
and dissolved in ammonia; and crystals of tungstate of ammonia obtained
from the filtrate by evaporation. (Anthon.) — In a similar manner,
L. Mayer (Zeiischr. Fhys. v. W. 5, 221) fuses I part of powdered wolfram
with 1 psurt of nitre and 2 parts of carbonate of potash, till the mix-
ture enters into tranquil fusion or nearly so; pours out the fused mass:
reduces it to powder; dissolves in the smallest possible quantity of water;
decants the solution from sesquioxide of iron; agitates it with j- of its
Tolume of spirit containing 95 per cent, of alcohol, which throws down
sesquioxides of iron and manganese (the latter being dissolved as man-
fame acid); filters; distils off the alcohol; precipitates the tungstic acid
y an excess of hydrochloric acid; boils the milky liquid rapidly over an
open fire, till it becomes yellow; collects the tungstic acid on a filter;
and lastly washes and dries it. — If the heat be too slowly applied, the
mixture remains white; the precipitated white powder must be collected
on a filter, again dissolved in potash, and after supersaturation with
hydrochloric acid, rapidly heated to the boiling point. (Mayer.) It is
only when small quantities of material are used in this process that the
tungstic acid is obtained yellow; larger quantities remain white. (Witt-
stein.) — The mixture of wolfram, nitre, and carbonate of potash, must be
ignited in a platinum or earthen crucible for about eight hours, till the
dark green mass fuses tranquilly and becomes thick, and a portion taken
out for trial diffuses itself in water with a dark green colour, the inso-
luble part no longer feeling gritty when rubbed with a glass stirring rod.
If the fusion is not sufficiently prolonged, the whole of the tungstic
acid does not combine with the potash, whence a portion is lost.
The fused mass is poured out; boiled with eight times its weight of
water, to which a small quantity of alcohol is added to precipitate the
manganese; and the filtrate precipitated by a quantity of chloride of
calcium equal to that of the wolfram used in the first instance. Hydro-
chloric acid is then added till the liquid becomes strongly acid, in
order to redissolve the carbonate of lime which is thrown down at the
same time; the precipitated tungstate of lime washed by decantation
and subsidence, and boiled with a large excess of hydrochloric acid, for
a quarter or half an hour, till the yellow colour of the mixture no
longer increases in depth: the tungstic acid is then thrown on a filter,
washed, and dried. — If the tungstate of lime is not thoroughly parified
from potash by washing, the tungstic acid set free by the hydroohlorio
acid does not exhibit a yellow colour. (Wittstein, Repert. 73, 82.) — [As
wolfram is generally mixed with quartz, the tungstic acid prepared by
the second method may contain silica, unless it has been previously
exhausted by ammonia, filtered, and then ignited.] — 8. Berzelius fuses
one part of wolfram with 2 parts of carbonate of potash; dissolves the
mass in water; filters; precipitates with nitric acid; digests the precipi-
tate (consisting of tungstic acid, nitric acid, potash, and silica), with
I
28 TUNGSTEN.
bihydroaalphate of ammonia, which dissolves the tangstic acid; filters;
throws dowD sulphide of tangsten by nitric acid; washes it with water
containing nitric acid, because it is soluble in pure water; dries the pre-
cipitate; and conyerts it by gentle roasting into pure tongstic acid. —
4. Wohler boils the wolfram, after fusion with an aqueous solution of
2 parts of carbonate of potash, and mixes the filtrate, while still hot, with
sal-ammoniac. On cooling, tungstate of ammonia crystallises out ; it is
then washed with water holding sal-ammoniac in solution (in which it is
less soluble than in pure water), and ignited; the tungstic acid thus obtained
is contaminated with a small quantity of potash .---5. For this reason it
is better, according to Wohler, to evaporate the alkaline filtrate with the
sal-ammoniac to dryness; heat the residue in a hessian crucible till the
sal-ammoniac is expelled; and prepare the brown oxide according to the third
method (p. 25), This oxide, by ignition in an open vessel, is readily
converted into tungstic acid. — H. According to Wohler, also, a mixture
of one part of powdered wolfram with 2 parts of chloride of calcium may
be fused in a hessian crucible for an hour; and the mass — after being
poured out, cooled, and reduced to powder — boiled with water to dissolve
out the chlorides of calcium, iron, and manganese. The tungstate of lime,
which remains undissolved, is then to be boiled with concentrated
hydrochloric acid to remove the lime; and the insoluble tungstic acid,
washed, dissolved in ammonia, filtered, evaporated to dryness, and
ignited. — 7. From Tungsten (native tungstate of lime) tungstic acid may
be directly separated by nitric acid.
Properties. Tungstic acid, when separated from any of its salts by
boiling with an acid, forms a soft, lemon-yellow powder; when prepared
by igniting tungstate of ammonia, it is sulphur-yellow, and retains the
crystalline form of the ammoniacal salt. Specific gravity := 5*274 ^Hera-
path), 6 12 (De Luyart), 7*1396 (Karsten). Its colour becomes aarker
when it is heated. — It is tasteless, and does not redden litmus, at least
after ignition. When rubbed up to a fine powder with water, part of it
goes through the filter, producing a white milky liquid. — [For its reaction
with fluxes, see p. 42.]
BerzelioB. Bachols. DeLayart. Aiken.
later. earlier.
W 96 .... 80 .... 79-768 .... 8009 .... 80 .... 80-64 .... 86*2
30 24 .... 20 .... 20-232 .... 1991 .... 20 .... 19-36 .... 138
W6» 120 .... 100 .... 100000 ... 10000 1, 100 .... 100-00 .... 1000
(WO» = 1183 + 3 . 100 = 1483. BcraeUus.)
DecompoHtions. Tungstic acid turns green when exposed to the direct
rays of the sun. (De Luyart.) Probably, the organic particles and dust
diffused in the air may exert a deoxidizing action upon it, so that a small
{>ortion of the blue oxide may become mixed with the tungstic acid: the
OSS of oxygen is, however, so slight, that it is impossible to estimate its
amount. — By strong ignition in an earthen crucible, tungstic acid is con-
verted into the blue oxide, which, on being heated to redness in the air,
absorbs 2 per cent, of oxygen, and is a^in converted into yellow tungstic
acid. (De Luyart.) [This efifect is doubtless produced by the carbonic oxide
in the furnace, since the blue oxide may likewise be obtained by igniting
tungstic acid in a current of carbonic oxide gSM»^ — By ignition with sul-
phur, it is likewise converted into the blue oxide. (De Luyart.) By
charcoal, at a low red heat, it is reduced to the brown oxide (by which
TUNGSTATES. 29
eans Bacbolz first obtained this oxide); at a higher temperature, it is
reduced to the metallic state. — By hydrogen gas, at a red heat, it is first
reduced to the dark blue oxide, then to the brown oxide, and lastly, at
a stronger heat, to metallic tungsten. (Berzelius.) — By potassium or
sodium, at a gentle heat, it appears to be reduced, with yirid incandes-
cence, to the metallic state (Gay Lussac & Thenard); — by ignition with
cinnabar, to sulphide of tungsten. (Berzelius.) — In contact with zinc and
hydrochloric acid, it first assumes a blue, then a black, and then a violet
colour, and is finally conyerted into the copper-coloured oxide. (Wbhler.)
Protochloride of tin, boiling vinegar, and other deoxidizing agents, convert
tnnestic acid into the blue oxide. An aqueous solution of sulphurous
acid has no action upon tungsten acid.
Co7nbinaii(ms,^a. With Water 1 (see p. 31, 4).
6. With Acids. — Tungstic acid appears to be insoluble in all acids,
excepting concentrated hydrochloric acid and hydrofluoric acid, and bat
slightly soluble even in those.
c. With Salifiable Bases, yielding the Salts of Tumostig Acid;
TuNGSTATEs.-— The alkaline and earthy tungstates are colourless. The
salts of tungstic acid have a very high specific gravity. They are fixed
in the fire unless the base is volatile. The only salts of tungstic acid
that are soluble in water are the tungstates of ammonia^ potash, soda,
lithia, and magnesia. None of the tungstates are dissolved by alcohol.
Those which are soluble in water have a bitter metallic taste, and produce
a disagreeable sensation in the throat. Sulphuric, hydrochloric, and nitric
acids decompose the tungstates. From the insoluble tungstates they sepa-
rate either pure tungstic acid in the form of a yellow powder, or a white
compound of tungstic acid, the composition of which has not yet been
determined with certainty. [That the substance thus separated is tungstic
acid, is proved by the following facts. When placed in contact with
hydrochloric acid and zinc or iron, it is first converted into the blue oxide
and then into the brown oxide, which, on removing the metal, is again
converted, by exposure to the air, into yellow tungstic acid ; it likewise
imparts the characteristic colours to borax and microcosmic salt before
the blowpipe (p. 42). The undecomposed tungstates, however, occa-
sionally give similar reactions with the fluxes; though several bases are
found to interfere with the result. (Berzelius.)] A solution of tungstate
of ammonia, potash, or soda, ^ves with sulphuric, hydrochloric, nitric,
acetic, and phosphoric acid, at ordinary temperatures, a white precipitate,
which contains the greater portion of the tun^tic acid (a small quantity,
however, remains dissolved); the precipitate is not soluble in excess of
either of these acids, except the phosphoric. Oxalic, tartaric, and citric
acids do not precipitate the above-mentioned alkaline tungstates. The
precipitate produced by hydrochloric or nitric acid becomes yellow after
the lapse of some time, but more rapidly if the liquid is heated; that pro-
duced by sulphuric acid remains white for a longer time, and does not
acquire so deep a yellow colour when heated. A solution of an alkaline
tungstate supersaturated with sulphuric, hydrochloric, phosphoric, oxalic,
or acetic acid, yields, on the introduction of a piece of zinc, a beautiful
blue colour, arising from the formation of blue oxide of tungsten; this
effect is not produced with nitric, tartaric, or citric acid. (H. Rose.) —
A solution of the above-mentioned alkaline tungstates gives, with lime-
water, and likewise with salts of baryta, lime, oxide of zinc, oxide of
lead, protoxide of mercury, and oxide of silver, white precipitates of
30 TUNGSTEN.
tnngstate of baryta, Ac. After an addition of bihydrosnlphate of
ammonia, the solution gives with hydrochloric acid, a yellow precipitate
of tersulphide of tungsten.
H Margueritt^ {J, Fharm. 3^ ser. 7, 222) describes a peculiar series
of alkaline tungstates containing excess of acid (from 2 to 6 atoms to
1 atom of base) which are obtained in the following manner: when
hydrated tungstic acid is kept for some time in a moderately concentrated
solution of a neutral alkaline tungstate, at a high temperature, a consi-
derable quantity of the acid dissolves; but on cooling, the saturated
solution again deposits tungstic acid. If it be now filtered, a second
separation of the acid takes place; and lastly, a salt crystallizes out,
which differs in form, according to its composition, but may be recrystal-
lized without decomposition. These salts are not decomposed by nitric,
hydrochloric, or sulphuric acid at ordinary temperatures, but only on
boiling. Those which contain two atoms of acid are less soluble in
water than those in which the proportion of acid is greater. On mixing
their solutions with caustic alkalis or alkaline carbonates, a precipitate is
formed, consisting of hydrated tungstic acid containing alkali, insoluble in
an excess of the precipitant at ordinary temperatures, but instantly disap-
pearing on adding the solution of a neutral tungstate. These salts have
a strong acid reaction and very bitter taste; when heated, they lose
water and become yellow and insoluble. This effect is only produced
at temperatures above 220°. If
Nature of the Precipitate produced in the Solution of Tungstate of
Ammonia, Potash, or Lithia, on the addition of an Acid,
All these precipitates agree in the following particulars : their taste
is sweet and bitter at the same time ; they redden litmus ; dissolve in
water, especially when hot, but scarcely at all in water containing any
portion of the acid by which they have been precipitated (hence, accord-
ing to Berzelius, they are precipitated by acids from an aqueous solution);
and are turned yellow by boiling with excess of sulphuric, hydrochloric,
or nitric acid.
The four following theories concerning the nature of this precipitate
are subjoined.
1. Dcbeele erroneously regarded the precipitate as pare tungstic
acid.
2. According to the brothers De Luyart, it is a compound of tnngstic
acid with small portions of the alkali with which that acid was pre-
viously combined, and with the acid used to effect its precipitation.
Hence it would appear that the precipitate is a compound of tungstic
acid with an alkaline sulphate, hydrochlorate, nitrate, or acetate.
The following precipitates were more particularly examined.
a. Tungstate of Ammonia precipitated hy Nitric Acid, — White
powder; tastes sweet at first, but afterwards very bitter; reddens litmus,
when ignited in closed vessels, it leaves a blue residue: in open vessels it
leaves yellow tungstic acid. With potash it evolves ammonia. Turns blue
on the addition of sulphuric acid. Dissolves sparingly in water; the solu-
tion becomes milky and blue on boiling, and deposits a blue powder.
The solution mixed with lime-water disengages an ammoniacal odour and
gives a precipitate of tungstate of lime; and the filtrate, after being
freed from the excess of lime by a current of carbonic acid gas, and after-
wards boiled and filtered, leaves nitrate of lime on evaporation.
PHOSPHIDE OF TUNGSTEN. 31
6. Tunffstate of Potash precipitated by Nitric Acid. — The precipitate
tastes sweet and then hitter, and produces an unpleasant sensation in the
throat. When heated it evolves nitric acid. The residue is yellow while
hot, hut white after cooling; insoluble, tasteless, but fusible before the
blowpipe. The precipitate turns yellow when treated with sulphuric,
hydrochloric, or nitric acid, which removes the potash; when distilled with
sulphuric acid, it gives off nitric acid vapours. A solution of this substance
in water is not precipitated by a small addition of the above-mentioned
acids, even on boiling, though its sweet taste is diminished and its bitter-
ness increased; but a larger quantity of acid added to a boiling solution
precipitates yellow tungstic acid. The solution decomposed with lime-
water, then filtered, first from tungstate and afterwards from carbo-
nate of lime, and subsequently evaporated, yields a mixture of nitrate of
potash and nitrate of lime.
e, Tungstic Add with Acetic Acid and Potask, — ». When an aqueous
solution of tungstate of potash is boiled with acetic acid and then left to
cool, feathery crystals separate from it These taste sweet at first, then
bitter, and redden litmus. On ignition, they first turn blue, then
yellow, and after cooling appear white. An aqueous solution of this
compound is precipitated by alcohol. The crystals dissolve in warm
acetic acid, producing a blue colour; on cooling, the solution becomes
colourless, and deposits on the sides of the vessel the tenacious mass y.
If the acetic acid solution of the crystals be boiled for a long time, its
colour is destroyed, and it deposits nothing on cooling.
/3. If the acetic acid solution is nearly evaporatea to dryness, and the
acetate of potash removed by repeated washing with alcohol, a very bitter
white powder remains, which is neutral to blue or red litmus, behaves in
the fire like «, and is readily dissolved by water; the solution is turned
blue by sulphuric acid, and gives a white precipitate of sulphate of copper.
7. If the precipitate 6, produced in a solution of tungstate of potash
by nitric acid, is dissolved in boiling acetic acid and then left to cool, it
deposits on the sides of the vessel, a white, adhesive, waxy mass, which,
after kneading in water, becomes tenacious like bird-lime ; in this state it
has a greasy and very sweet taste, but after drying, becomes dark grey
and solid, and tastes very bitter. It behaves in the fire like «. The
aqueous solution reddens litmus, turns blue on the addition of sulphuric
acid, and precipitates sulphate of copper.
The compounds a, 0, and y, when dissolved in water and treated with
lime-water and carbonic acid as in «, yield acetate of potash, which,
however, in the case of /3, is mixed with carbonate of potash. [So far De
Luyart.1
3. According to Berzellus, the precipitate consists only of tungstic acid
combined with a small quantity of the acid used for precipitation, and
with water. According to the same authority, the precipitate produced
by sulphuric or hydrochloric acid, is white and very soluble in pure
water; that produced by nitric acid, yellow and but sparingly soluble.
4. Aocoiding to Anthon^ the precipitate consists of hydrated tungstic
acid, which is also formed when the anhydrous yellow tungstic acid is washed
for a long time with water, the water at last passing milky through the
filter, in consequence of the formation of hydrate of tungstic acid. An then
examined the precipitate produced by nitric acid. A warm solution of
the tungstate of potash or soda remains clear on the addition of nitric
acid ; but, on cooling, deposits a white, bulky, gelatinous mass, which,
when thoroughly wasned and dried, appears brilliant, of a yellowish-grey
32 TUNGSTEN.
colour^ and translnoent^ but sometimes black and opaque; it also reddens
litmus. The precipitate loses by ignition, 13*5 per cent. (2 At) of water,
and leaves a bluish-black residue, which, after being boiled with nitric
acid and subsequently ignited in the air, is conyerted without alteration
in weight, into yellow tun^stic acid. [Potash was not sought for.] The
precipitate when immersed in water immediately after preparation, fre-
quently assumes a blue colour, the water itself acquiring a violet tint,
even without exposure to the direct rays of the sun : if the water contains
chlorine, the colouring does not take place. The precipitate, when finely
pounded, dissolves in from 250 to 800 parts of cold, and in 30 parts of
boiling water; the hot solution becomes turbid on cooling; the cold solu-
tion is not clouded by the addition of a strong acid. The precipitate
dissolves with effervescence in the alkaline carbonates. (Anthon.)
H Laurent (Ann. Chim, Phys. 3, 21, 54), from an examination of
tungstic acid and its ammoniacal salts, concludes that it is susceptible of
at least 5 or 6 modifications, and distinguishes it as Tungntic (the ordi-
nary variety), Faratungstie, Metatungstic, Isotunggtic, and Polytungitic
acid, according to its saturating power (similarly to phosphoric acid).
Paratunggtic add is that which exists in the bitungstates with or without
water, and the formula of its salts is, W*0", 2M0. Metatungstic acid is
obtained by boiling paratungstate of ammonia for several hours, and
afterwards heating the dry salt. The solution when evaporated, yields
very soluble octohedrons. It is not precipitated by hydrochloric acid:
W'0',MO, wither without water. Isotungttie add: W'u'jMO. Prepared
by boiling metatungstate of ammonia with excess of ammonia, and heating
the dry salt as before. The ammoniacal salt is sparingly soluble in water.
The solution deposits isotungstic acid on the addition of acids. Poly-
tungstic add: probably W*0^*, 3M0. Formed by treating the yellow
acid obtained from wolfram with ammonia, and slowly evaporating the
solution; paratungstate and isotimgstate of ammonia separate first, and
the mother-liquor then separates into two strata, one of which is brown
and of a syrupy consistence, and is converted on drying into a readily
soluble, crystalline mass. This liquid mixed with boiling hydrochloric
acid, yields a white precipitate of polytun^stic acid which is not gela-
tinous, and does not become yellow after boiling. Polytungstic acid is
characterized* by yielding with ammonia, a very soluble salt which forms
a gummy mass on evaporation. IT
Tungsten and Phosphorus.
Phosphide of Tungsten. — Prepared by Pelletier, but not further
esamined.
Tungsten and Sulphur.
A. Sulphide of Tungsten. — a. Bistdphide; Tungstous Sulphide,
Sulpkotungstous Add, Wolfram-pyrites, — 1. A mixture of one part of
tungstic acid with 6 parts of cinnabar is pressed into an earthen crucible,
which is fitted with a cover and placed in a larger crucible filled with
charcoal, and the whole strongly ignited for half an hour. — 2. Vapour of
sulphur or hydrosulphuric acid gas is passed over tungstic acid strongly
ignited in a porcelain tube. (Berzelius.) Sulphur ignited with tungstic
acid, acts on it but imperfectly. (Berzeliub.)
SULPHIDE OF TUNGSTEN. S3
Soft, ffreyiflh-black powder^ whichy when submitted to pressure, acquires
jthe metallic lustre and a steel-grey colour. (Berzelius.)
Berzelins.
1. 2.
W 96 .... 75 .... 75-04 .... 74'891
28 32 .... 25 .... 24-96 .... 25-109
WS» 128 .... 100 .... 100-00 .... 100000
After prolonged ignition in the air, it leaves 93*5 per cent, of a brown
oxide, which, when very strongly heated, turns green without any change
of weight, and must be regarded as tungstic acid. By aqua-regia, it is
converted into tungstic and sulphuric acid. (Berzelius, Ann. Phil. 3, 245.)
At a red heat, it slightly decomposes aqueous vapour, but with greater
facility at a higher temperature. (Regnault.)
6. Teriulphide, Tungttic Sulphide^ Sulpfiotunggtic acid. — ^1. Formed
by dissolving tungstic acid in bihydrosulphate of potash, and precipitating
the solution by an acid.
2W08 + 3(K0, 2HS) + 3S0» = 2WS» + 6H0 + 3(KO, S0»).
2. By saturating an aqueous solution of tungstate of ammonia with hydro,
sulphuric acid gas, precipitating by an excess of acid, then washing the
precipitate with cold water and drying it. As the tersulphide of
tungsten is somewhat soluble in water, the water, after the first yellow
liquid has passed through the filter, becomes continually darker in colour,
and on evaporation, leaves tersulphide of tungsten in the form of a brown
residue less soluble in water than before. If the liver-coloured precipitate
is boiled with hydrochloric acid, it becomes darker in colour, and ulti-
mately blackbh-blue, from closer aggregation of its particles, but remains
soluble in water. (Berzelius.)
The dried precipitate is black, but yields a liver-coloured powder.
When heated in a retort it evolves sulphur, and is converted into
bisulphide of tungsten. At the same time it gives off traces of water
and hydrosulphuric acid, the latter being either combined with the sul-
phide of tungsten, or, what is more probable, produced, together with
portions of tungstic acid, by the decomposition of the mechanically com-
bined water. A small quantity of hydrosulphuric acid is likewise evolved
by merely boiling the sulphide in a retort with water. It dissolves in an
aqueous solution of potash or of carbonate of potash (in the latter case
without effervescence, because bicarbonate of potash is produced), yielding
a dark brown solution, which contains a compound of tersulphide of
tungsten with sulphide of potassium, besides tungstate of potash. If the
solution is boiled in an open vessel, it attracts oxygen, and becomes
lighter in colour, passing through green into yellow. Solution of ammonia
dissolves dry tersulphide of tungsten very slowly, but the recently pre-
cipitated sulphide somewhat more readily. The alkaline bihydrosulphates
dissolve it, with evolution of hydrosulphuric acid. Water dissolves the
tersulphide in small quantity, especially with the aid of heat. From the
yellow solution, sal-ammoniac and acids precipitate the greater part of
the substance. (Berzelius.)
Tersulphide of tungsten forms with the more basic metallic sulphides,
a class of compounds called StdphO'tungstaUs, which generally have the
composition, MS,WS', the symbol MS representing the more basic metallic
sulphide. The compounds with the alkali-metals are obtained by satu-
rating an aqueous solution of the tungstate with hydrosulphuric acid:
VOL. IV. D
34 TUNGSTEN.
KO,WO'+4H8 = KS,WS*+4HO. The iaat poriieM of tiie dkaUne
tangstate are decomp<MBed with great difficaltj by the hydioenlphnric acid.
The insoluble snlpho-tangstates are prepared by decompoBing a solution
of one of the soluble compounds with another metallic salt. The com-
pounds containing the alkali-metals are red and crystallizable, taste of
sulphur, and yield a yellow or red solution with water. This solution
may contain MO, HS + WO', SHS. The liquid gradually becomes colour-
less when exposed to the air, depositing sulphnr and tersulphide of tung-
sten, while tungstate and sulphate of the alkali remain ia solution. If
the base is in excess, oxidation takes place more rapidly and without
separation of insoluble matter. The aqueous solution is still capable of
diseolying an additional quantity of tersulphide of tungsten, which colours
it deep brown ; in this case, a more careful addition of acid is neoessary^
An excess of acid precipitates the tersulphide of tungsten, with evolution
of hydrosulphuric acid and formation of an alkaline salt. Those oxides
of the heavy metals which letain their oxygen with but feeUe affinity,
are decomposed in the solution, producing an alkaline tnngstate and
a sulphide of the metal employed. («. g. KS, WS» + 4CuO = KO, W0»
+ 4CuS). (Berzelins.)
B. TuNOSTATB OF Tbrsulphidb 09 TtJiicwTBN % — If tfi aqoaons
solution contains an alkaline tangstate and aa alkaline snlpho-^ngstate
together [MO,WO'+MS,WS*], the addition of an add causes the sepa-
ration of a light, reddish-brown componnd, which is not blackened by
boiling with hydrochloric acid, bat when dry evolves snlphuroos acid on
ignition, and leaves a greyish blue mixtare of bisnlphide and bine oxide
of tungsten. (Berzelius.)
C. Sulphate of Tungstic Acid % — Concentrated nitric acid produces
in an aqueous solution of tersulphide of tungsten, and snlphuric acid in
a solution of tangstate of ammonia, a white heavy precipitate, consistinfi^
of sulphuric acid, tungstic acid, and water. On ignition, this componnil
evolves sulphuric acid, and leaves pure tangstic acid; it likewise dis-
solves in water, but is again precipitated by nitric or solpkuric acid.
{Berzelius.)
Tungsten and Bbouine.
A. OxY-BROHiDE OF TuNGSTBN. — Formed by passing vapour of bro*
line in small quantities over an ij " *
charcoal. Its iformula is WO^+W^
mine in small quantities over an ignited mixture of tungstic acid and
iformula is WO^+WW.
B. Tungstate op Bromide of Tungsten. — Formed when the same
mixture is raised to a higher temperature, and bromine vapour passed
over it in greater quantity : W0'-|-2WBr', (Bonnet| /. jpr. Chem.
10, 206.)
A. Bonnet. B. Bonnet.
4W ....
6Br ....
60 ....
384
392
40
• •••
• ■•t
4706
48-04
4-90
• »«•
• •••
• • ■
45-97
4800
6-03
6Br
30
288-0
470-4
24
■ •■«
• •••
36-81
6012
307
■ •»•
• •••
37
60
3
816 .... 10000 .... 10000 782-4 .... 10000 .... 100
CHLOKIDB OF TUNGSTEN. 35
Tungsten and Chlorine.
A. Chloride of Tungsten.— -a. Bichloride, — Tangsten heated in
oUorine gas takes fire and buns with a dull red lights sometimes pro-
diicing small dark red needles collected together in woolly tufts^ some-
times a deep red, dense^ fosed mass^ with glassj fractore. The com-
ponnd foses readily and then boils, and is converted into a red rapour
darker in ooloor than nitrons aeid. (H. Davy, Wohler.)
dOcuUtioii. Mola^d.
W W-O ._ 57-65 ..„ 67-61
2C1 ^ 70-8 .^. 42-45 .... 42-39
WCP 166-8 .... 10000 Z 100-00
When immersed in water it rapidly assames a violet eolonr, and is
gradually resolved into brown oxide of tungsten and aqaeoos hydix>-
ehloric acid. (Wohler.) The product of this action is a blue ozide, which,
after being washed and dried, does not> when ignited in the air, absorb
7*1 per cent, of oxygen, as pare tungstous oxide should do, but at most
only d'2 per cent.; probably because, after being separated from the
chloride of tungsten, it is converted into a higher oxide by exposure to
the air. (Malaguti.) — It dissolves in solution of potash with evolution of
hydrogen gas, yielding tnagstate and hydrochlorate of potash. With
ammonia it behaves in the same manner, excepting that the solution
is yellow, and when heated becomes colourless and deposits brown oxide.
(Wohler.)
6. Terchhride. — Dry chlorine gas is passed over heated bisulphide of
tungsten. (Wohler.) For this purpose a tube with five bulbs is used, the
end being drawn out to a fine point. The first bulb contains the sulphide
of tungsten heated by means of a spirit-lamp. At first a white cloud
appears, which condenses into white flakes and is expelled by warming
the bulbs. After this, the red compound 6 passes into the second bulb
and collects in the form of an oily liquid. Another less volatile compound
[which Malaguti regards as terchloride of tungsten : see beloni] is like-
wise mixed with it. To purify the red compound 6 from this substance,
the second, third, and fourth bulbs are warmed in succession, so that it
finally collects in the fifth bulb in a state of purity, while the less
volatue compound remains behind. The fifth bulb is then separated from
the rest by nision in the flame of a spirit-lamp. (Malaguti.)
Terehloride of tungsten crystallizes in very lou^, transparent needles
of a dark red colour; it fuses readily, and on cooling, recrystallizes in
needles which adhere to the glass vessel. It is easily converted into
vapouT; the colour of which resembles that of hyponitric acid. (Wbhler.)
Calenlatfea. ^ MalagatL
W ...........«.......^. 96*0 ..« 47-48 .... 51-35
3C1 106-2 .... 52-52
WCP 202-2 .... 100-00
t«««
#•••
Malaguti, from his analysis of the compound b, deduces the formula
WH}R Nevertheless, he satisfied himself that when treated with water,
in the absence of all oxidising agents, it is immediately converted into
hydrochloric and tungstic acids without any evolution of hydrogen gas;
D 2
SG TUNGSTEN.
whereas W*C1* would necessarily be resolved into lijdrocliloric acid
and blue oxide of tungsten. In the preparation of the compound h, a
second and less Tolatile substance is formed, which Malaguti, according
to his own analysis, regards as tercbloride of tungsten, but which, accord-
ing to H. Rose's experiments, is a compound of tungstic acid with ter-
cbloride of tungsten (described under B). The formation of tungstic acid
probably took place because the chlorine which acted on the sulphide of
tungsten was not quite free from air or moisture. Probably also the volati-
lization of the compound h from one bulb into the other did not suffice to
separate this tungstate of chloride of tungsten completely, so that the
compound 6, when decomposed by water, yielded too large a quantity of
tunffstic acid, and Malaguti calculated the tungsten accordingly ; and as
he did not estimate the amount of chlorinci the matter remained unex-
plained.
Tercbloride of tungsten is almost immediately decomposed by exposure
to the air (by the action of the moisture present) into hydrochloric and
tungstic acicLs ; in water it swells up with a hissing noise and evolution
of heat, like lime in the act of slaking, and is almost entirely converted
into hydrochloric and tungstic acids. ( Wbhler.)
B. Tungstate of Chloride of Tungsten. — Dry chlorine is passed
over brown oxide of tungsten heated in the bulb of a glass tube. Under
these circumstances, this brown oxide becomes incandescent, whereas the
black oxide does not. The bulb becomes filled with dense yellowish
vapours which condense into scales. (Wohler.)
3W02 + 3C1 = WW, 2W0>
Yellowish white scales, resembling boracic acid; readily yolatllized,
even before fusion, in dark yellow vapours, which have a pungent odour
like that of hydrochloric acid. (Wohler.)
Calculation. U. Roie. Malagnti. Bonnet*
3W 288-0 .... 6513 .... 6667 .... 4672 .... 65-2
3C1 106-2 .... 2401 .... . .... .... 400
60 480 .... 10-86 .... .... .... 4-8
WCl»,2WO» 442-2 .... 10000 ~ Z .... 100-0
According to Bonnet, the formula should be 2WCP, W0\ This
substance, when strongly heated, is partially resolved into fixed tungstic
acid, volatile bichloride of tungsten, and cnlorine gas. Hence, a small
quantity of bichloride of tungsten (separable by its greater volatility) ia
formed during the preparation, partial decomposition taking place at the
heated sides of the glass bulb. (H. Rose.) When exposed to a damp
atmosphere it is converted, in the course of a few hours or days, into
hydrochloric acid gas and tungstic acid; water decomposes it rapidly,
the products being tungstic and hydrochloric acids. When this compound
is volatilized over a spirit-lamp, the aqueous vapour generated by the
combustion decomposes the volatile chloride of tungsten, producing
vapours of hydrochloric acid, and a luminous smoke, which dimuies itself
through the room, and afterwards condenses into thin yellow flakes
of tungstic acid. Solution of ammonia dissolves the chloride of tung-
sten instantaneously, with a hissing noise and ^reat rise of tenipe*
rature, the products being tungstate and hydroohlorate of ammonia.
(Wohler.)
TUNGSTATB OF AMMONIA. 37
C. HtbrochlObate of Tttngstig Acid. — Highry concentrated hydro-
chloric acid dissolves tungstic acid in small quantities; vrater precipitates
from the solution a white curdy substance ^tungstic acid containing
hydrochloric acid?). (Berzelius.) The precipitate obtained by super-
saturating a solution of tungstate of ammonia with hydrochloric acid is
likewise regarded by Berzelius as a compound of tungstic and hydro-
chloric acids.
Tungsten and Fluorine.
Fluoride op Tungstjen and Hydropluate op Tungstic Acid. —
Tungstic acid after ignition is sparingly dissolved by aqueous hydrofluoric
acid; that which is prepared in the wet way forms with hydrofluoric
acid a yellow milky liquid soluble in a large quantity of water. The solu-
tion^ when slowly evaporated, yields a yellow syrup, which, at a higher
temperature, gives oft' a portion of its acid and solidifies to a greenish,
fissured mass. This mass is not decomposed when ignited in a close vessel;
it redissolves imperfectly in water, forming a milky liquid as above;
the insoluble part consists of tungstic aoid, which retains a portion of
the hydrofluoric acid so obstinately, that the latter can only be expelled
by igniting the tungstic acid with lumps of carbonate of ammonia. The
solution contains tungstic acid with excess of hydrofluoric acid. Ter-
flnoride of tungsten forms with the more ba«ic metallic fluorides, com-
pounds which have not yet been isolated, and are known only in combi-
nation with tungstates of the metallic oxides. (Berzelius,)
Tungsten and Nitrogen.
A. Nitrate op Tungstic Acid. — The lemon-yellow precipitate pro-
duced in a solution of tungstate of ammonia by nitric acid mnst, accord-
ing to Berzelius, be regarded as thus constituted. It dissolves in pure
water, forming a yellow solution, and is again precipitated on the addi-
tion of nitric acid.
B. Tungstate op Ammonia.— a. Monotungstate, — Obtained in solu-
tion by leaving tnngstic acid for some time in contact with ammonia. The
liquid, added to a solution of chloride of calcium, precipitates mono-
tnngstate of lime; but when evaporated, it evolves ammonia and yields
the bitungstate. (Anthon.)
h. Biiungttaie of Ammonia, — Tungstic acid separated from wolfram
by acids, dissolves in ammonia with ease; the ignited acid less readily;
and the blue oxide more slowlv still. — 1. Tungstic acid prepared from
wolfram by the first method (p. 26) with hy£ochloric acid and aqua*
regia, is digested in aqueous ammonia; and the solution filtered and eva-
porated to the crystallizing point. The solution prepared with the aid
of heat, deposits yellow nakes on cooling, which dry up to a yellowish
brown, transparent, resinous mass, consisting of tungstic acid and sesqui-
oxide of iron. The liquid filtered from this substance yields pure crys-
tals of the salt. The mother-liquor leaves, on evaporation^ a gummy
mass (before remarked by Bucholz, and declared to be the pure salt),
likewise consisting of tungstate of ammonia, but probably of difl^erent
composition. — 2. When ft hot aqueous solution of monotungstate of
38 TUNGSTEN.
pota«b or soda is mixed with sal-ammoniao^ ammonia is set free, and,
as the liquid cools, bitongstate of ammonia crystalliaes oat. (Wbhler,
Antkon.)
The salt crystallizes in fonr-sided needles containing water, or in
rhombic tables, having an acrid, bitter, metallic taste. According to
AnthoU; it reddens litmus slightlj.
Tanq. &
BeneliuB. Anthon. Hedit.
Crystallized. 1. 2.
NH' 17 .... 6-18 .... 5-63 .... 6338 .... 6 .... 78
2W03 240 .... 87-27 .... 88*80 .... 87*000 .... 87
2HO 18 .... 6*55 .... 5*57 .... 6'662 .... 7
NH*0,2W0» + Aq. 275 .... 10000 .... 10000 .... 100000 .... 100
The crystals do not undergo any alteration in the air. They cannot,
however, be rendered anhydrous without decomposition. At a red heat
they evolve water, ammonia, and nitrogen gas, and leave blue oxide of
tungsten, or, if air is admitted, tungstic acid. (De Luyart.) — They dis-
solve in 25 or 28 parts of cold water, but not in alcohol. ^Anthon.)
The aqueous solution evolves ammonia when evaporated, and becomes
more acid in consequence. (De Luyart.) — It yields a white precipitate
with nitric acid, which, after long standing, or immediately on boiling,
becomes yellow. IT Margneritt^ has succeeded in forming two new com-
pounds of tunestic acid with ammonia: the first — NH*0,3WO'-t-5HO—
forms octoheoral crystals, which melt under water like phosphorus; the
second — NH*0,6WO'+6HO — separates in definite, scaly crystals. %
C. SuLPHO-TUNGSTATE OP Amhonium. — NH*S,WS'. — If a concentrated
solution of tungstate of ammonia is saturated with hydrosulphuric acid
gas, this compound gradually separates in difficultly soluble, yellowish red
crystals. The motner-liquor yields by spontaneous evaporation yellow
rectangular tables, which in other respects possess similar characters to
the above, and are consequently dimorphous. The crystals decrepitate
strongly when heated, evolve water and hydroeulphate of ammonia,
and leave grey bisulphide of tungsten, having a metallic lustre and the
form of the crystalline fragments after decrepitation. They dissolve
more readily in pure water than in water containing a saline substance in
solution. The solution is slowly decomposed by exposure to the air.
(Berzelius.)
D. Fluoride of Tungsten with Hydroflvati of Ammonia, or
Fluobidb of Tungsten and Ammonium. — Ammonw-Jluoride of tu9i^fit€n,
— Analogous to the corresponding potash-salt^ both in external appearance
and in composition. (Berzelins.)
Tungsten and Potassium.
A. Tungstate op Potash. — a, Monotungstate, — 1. Tungstic acid is
digested with an equivalent quantity of aqueous caustic potash or carbonate
of potash (in the latter case carbonic acid is expelled), the solution filtered^
and evaporated to the crystallizing point. — 2. One part of carbonate of
potash is heated to fusion in an iron crucible, and powdered wolfram
thrown into it as long as efifervescence continues — for which purpose about
one part is necessary. The mass is kept for some time in a state of fusion/
TUNGSTATB OP POTASH.
89
after whicli it is poured out, broken to pieces, boiled in water, and tlie
solution filtered and evaporated to dryness; the residae is then treated
with an equal weight of luke-warm water, which generally leayes a por-
tion of bitnngstate of potash undissolyed, — then filtered, partially eyapo*
rated, and left to crystallize* (Anthon.)
The salt has a rough, bitter taste and strong alkaline reaction; it
foses just below redness, and forms a transparent liquid, which solidifies
to a crystalline mass on cooling. Crystallizes from an aqueous solution in
hydrated six-sided prisms, with two of their lateral faces broader than the
rest; and either having the tenninal edges replaced by planes, or acumi-
nated, or with dihedral summits resting on the broader lateral laces.
Attracts moisture from the air, and dissolves in an equal weight of cold
water and in half its weight of boiling water, the salt b often separating,
and the solution retaining an excess of potash. Sulphuric, hydrochloric,
or nitric acid, produces a white precipitate in a dilute solution of the
salt (p. 31); but with a eoncentrated solution, on boilings these acids form
a yellow precipitate of pure tungstic acid. (Anthon.)
AnhydroQS.
KG 47-2 .... 28-23
W0« 120-0 .... 71-77
Crystallized. Anthon.
KG .... 47-2 .... 22-24 .... 220
WG«.... 1200 .... 56-55 .... 57'5
6HG.... 450 .... 21-21 .... 205
KG,WG«.... 167-2
10000
+ 5Aq. 212-2
100-00
100-0
h, BiiungslaU, — 1. To the salt a, in a state of fusion, a quantity of
tun^tic acid is added equal to that which it contains; and the mass when
cold is broken up, boiled in a small quantity of water, filtered, and left
to crystallize on cooling. — 2. To a boiling aqueous solution of caustic
potash, carbonate of potash^ or monotuugstate of potash, tungstic acid is
added as long as it dissolves, and the liquid filtered boiling hot and left
to cool. The resulting crystalline powder becomes anhydrous when
heated.
The anhydrous salt turns yellow when heated, and fuses below red-
ness to a clear yellow liquid, which, on cooling, solidifies in a bluish or
freenish mass of crystals. It reddens litmus^ and tastes like the sah a,
ut not so strong. The hydrated crystalline powder appears under the
microscope to eonsist of rhombic tabular crystals, which, by replacement
of the edges, are converted into hexagonal prisms. The crystals are per-
manent in the air. They dissolve in 100 parts of water at 16% and in 8^
parts of boiling water, separating for the most part as the liquid cools.
The solution is nrecipitatea white by acids, but not till after some time
if largely diluted. (Anthon.)
Anhydrous.
KG 47-2 .... 16-43
2W03 2400 .... * 83-57
KG ...
2WO»
2HG..,
Crystallized. Anthon.
47-2 .... 15-46 .... 14-25
2400 .... 78-64 .... 7975
18^0 .... 5-90 .... 600
KG,2WG»,... 287-2 .... 10000 -♦•2Aq..... 305-2
100-00
100-00^
e. Hyperacid SaU.^^'Wh&ji an excess of tungstic acid is fused with
hydrate or carbonate of potash, a bluish grey, crystalline, metallic-shining
mass ia produced; it appears to yield the salt h to boiling water. (Anthon.)
T Marffueritt^ describes a pentatungstate of potash— KO, 5W0' + 8H 0—
aryok ferms prismatic crystals. IF
40 TUNGSTEN.
C. SuLPHO-TUNQSTATE OP PoTAssiuM. — KS,WS*. — Foitned by treating
tungstate of potash with hydroenlphuric acid, or by dissolving tungstic
acid or tersulphide of tangsten in hydroBulpbate of potash, or tersul-
phide of tungsten in caustic potash. — An aqueous solution of mono-
tungstate of potash is saturated with hydrosuiphuric acid gas, and the
brownish yellow solution evaporated, either in vacuo over potash, or
simply by exposure to the air. In the former case, small yellow
crystals are obtained; in the latter, pale red, broad, flat, four-sided prisms,
with dihedral summits. The crystals are anhydrous. When heated in
a close vessel, they fuse without decomposition, and form a dark brown
mass, which becomes brownish yellow on cooling. The salt dissolves in
water, forming a brownish yellow solution^ from which it is precipitated
by alcohol, after some time^ in delicate, cinnabar-coloured prisms; but the
precipitation is not complete, for the salt is also slightly soluble in alcohol.
By careful addition of an acid to the aqueous solution, the compound is
converted into KS, 2 WS', the dark brown solution of which leaves a black
mass on evaporation. (Berzelius.)
Crystallized. Beneliiis.
K 39-2 .... 19-68 .... 19'91
W 96-0 .... 48-19 .... 46-80 |
4S 640 .... 3213
• •ft
KS,WS» 199-2 .... 10000
H Tungstate op Potash and Ammonia.— NHK), KO, 4W0*H-6H0.
•-Prepared by Margueritte. IT
D. SULPHO-TUNOSTATE OP POTASSIVM WITH NiTRATB OP PoTASH. —
2(KS, WS»^ + KO, NO".— If the solution of monotungstate of potaah which
is satnratea with hydrosuiphuric acid, contains nitre — ^brilliant, ruby-red,
transparent, anhydrous crystals are obtained, which remain unaltered
after repeated crystallization. The crystals explode like gunpowder just
as they begin to melt, and leave a pale yellow mass, from which water
extracts sulpho-tungstate of potassium and tungstate of potash, leaving an
insoluble residue of bisulphide of tungsten. Sulphuric or hydrochlorio
acid disengages hydrosuiphuric acid gas, and with the aid of heat, nitric
oxide also; whereupon, a portion of the precipitated tersulphide of tung-
sten immediately turns yellow. Hydrated oxide of copper converts the
solution of this compound into a solution of nitrate and tungstate of cop-
per, with separation of sulphide of copper. The compound is very soluble
in water, and dissolves almost as readily in cold water as in hot The
solution has a deejp red colour, and the salt is precipitated from it by
alcohol in crystalline grains. (Berzelius.)
Tungsten and Sodium.
A.^ Tungstate op Soda. — a. Monotungstate, — Prepared by dissolving
tungstic acid in solution of canstic soda, or by fusing wolfram with car-
bonate of soda, and exhausting with water. Anthon projects powdered
wolfram into fused carbonate of soda as long as it causes effervescence;
keeps the mass at a red heat for some time; reduces it to powder when cold;
boils it for some time with water; filters the solution; and evaporates to
the crystallizing point. — By heating the crystals, the salt may be obtained
anhydrous. In this state it is white, opaque^ and permanent in the air^
TUNGSTATE OF SODA. 41
Mid has a bitter, roa^li^ saline taste, and alkaline reaction.. It fuses
below a red heat, and forms a clear liquid, which solidifies to an opaque,
crystalline mass. (Anthon.) Before the blowpipe, the fused salt first
becomes blackish blue and afterwards reddish brown. It is not decom-
posed by ignition in an atmosphere of hydrogen. (Wbhler.) The crystals
deposited from an aqueous solution are translucent, of a pearly lustre, and,
according to Yauquelin & Hecht, have the form of long, four-sided laminsd,
—According to Anthon, of rhombic tables. — The crystals dissolye in
4. parts of cold and in 2 parts of boiling water (Vauquelin & Hecht); in
1*1 pt. of cold and in 0*5 pt. of boiling water (Anthon).
Anhydrous. Crystalline. • Anthon.
NaO 31-2 .... 20-63 NaO 31-2 .... 18-44 .... 18-1
W0» 120-0 '.... 79-37 W0» 120-0 .... 70-92 .... 71-0
2HO 18-0 .... 10-64 .... 10-9
NaO,WO» 151-2 .... 10000 +2Aq 1692 .... 10000 .... 1000
6. BUungstaie, — 1. Formed when tungstic acid is thrown into a
fiised mass of the salt a. — Wbhler adds the tungstic acid as long as it
continues to be dissolved, and then allows the mass to cool. — Malaguti, to
avoid obtaining an acid salt, uses a smaller quantity of tungstic acid, so
that a portion of the salt a remains unacted on, and is afterwards dis-
solved out by boiling water, leaving the salt h in the form of scales. —
2, A hot solution of caustic soda or of carbonate or monotungstate of soda
is completely saturated with tungstic acid; the hot filtrate allowed to
crystallize; and the mother-liquor again evaporated, to obtain an addi-
tional quantity of crystals. (Anthon.) — H 8. An aqueous solution of
monotungstate of sooa (as obtained by fusing a mixture of wolfram and
carbonate of soda, and exhausting with water) is mixed with hydrochloric
acid till the precipitated acid is no longer dissolved on agitation. The
liquid is then filtered — evaporated — separated from the tungstic acid
which first separates — and then from the chloride of sodium — and lastly
set aside to crystallize. (Margueritte.) H
The fused anhydrous salt obtained by the first method, crystallizes as
it cools, forming long needles on the surfiEu;e. (Wohler.) In the fused
state it forms a transparent, yellowish liquid. (Anthon.)— When ignited
in a current of hydrogen gas, it assumes a copper colour, which is at first
superficial only, but gradually extends throughout the mass, and on cool-
ing, changes to golden yellow; it appears to be converted by this process
into a mixture of the salt a with tungstate of tungstens oxide and soda.
(Wdhler.) — The crystals deposited from an aqueous solution, which also
contain water, are striated rhombohedrons resembling those of nitrate of
soda; they are permanent in the air; redden litmus; and have at first a
sweet, afterwards a rough, bitter taste, and dissolve in 8 parts of cold
water. (Anthon.) [The white unctuous scales which Malaguti obtained
by the first method appear to be less soluble.]
Anhydrous. Cryst. from water. Anthon.
NaO 31-2 .... 11*51 NaO 312 .... 1016 .... 9
2W0» 2400 .... 88-49 2W0» 2400 .... 7812 .... 79
4H0 360 .... 11-72 .... 12
Na0,2W05 ... 271-2 .... 10000 +4Aq 307-2 .... 10000 .... 100
H Margueritte describes this salt as forming laminated crystals which
contain 4^ atoms of water, and are decomposed by acids at ordinary
42 TtJNGStSK*
temperatupes. He ako meDiions a salt oontaining 4 thtomn of acid =
NaO,4WO»+3HO. IT
Tnngstic acid ^ves with carbonate of soda, on platinnm wire before
the blowpipe, a transparent, dark jellow glass, which, on cooling, crys-
tallizes to a white or jellowiih white opaqne nass. By exposure to the
inner flame on ofaareoal, tungsten is reduced. (Berzelins.)
C. Tungstie acid yields with borax, in the outer blowpipe flame, s
transparent glass, which remains clear even after gentle flaming; in the
inner flame, the glass acquires a yellow colour, darker in propo^ion to
the quantity of tungstie acid present; on cooling, it changes to blood-red.
The addition of tin renders the glass milk-white on cooling. (Berzelius.)
D. With microcosmio salt, in the outer flame, tungstie acid gives a
colourless or yellowish glass; in the inner flame, a splendid blue. The
addition of tm accelerates the appearance of the blue colour. When
either alumina or silica is present, the tin is necessary to bring out the
colour. If iron is present, the glass assumes a blood-red colour in the
inner flame; on the addition of tin, however, this colour changes to green
or blue, especially if the substance does not contain too large an excess of
tungstie acid. (Berzelius.)
E. SuLPHo-TUNGSTiTE OF SoBiUMf — NaS,3WS^ — The blackish-grey
substance, insoluble in water and decomposible by aqusrregia, which,
according to W5hler, remains after igniting a mixture of tungstate of
tungstens oxide and soda with sulphur, must be regarded as a compound
of this nature (p. 47).
F. SuLPHO-TUNOflTATB oF SoDiuM. — NaS,WS*. — Crystallizes with
difficulty from a highly concentrated aqueous solution ; with greater
facility, however, from an alcoholic solution, by spontaneous evaporation.
Forms an entangled mass of crystals, which rapidly attract moisture from
the air, and become yellow. Xf an excess of sulphide of sodium is used,
a salt equally soluble in alcohol is produced, which soon becomes moist in
the air, and oxidizes at the same time. (Berzelius.)
Tungsten and Lithiitm.
TvNOSTATE OF LiTHiA. — a. HonotungstoU. — I. Tungstie acid, after
ignition, is dissolved in a boiling aqueous solution of carbonate of lithia;
and the solution, which is but slowly formed, evaporated to the crystal-
lizing point. (G. Gmelin.) — 2. Tungstie acid is projected into fused car-
bonate of lithia as long as effervescence is produced; and the resulting
mass dissolved in water and set aside to crystallize. (An thou.) The salt
forms short, thick, oblique rhombic prisms, of a sharp, very sweet, and
roughly bitter taste, which dissolve in water with tolerable facility.
(C. Gmelin.) Octohedrons apparently, having an alkaline reaction; very
soluble in water. (Anthon.)
b. BiTUNGSTATE. — Preparation, similar to that of the bitungstate of
soda. Crystallizes readily; reddens litmus; and has a saline, bitter, and
afterwards somewhat rough taste* Permanent in the air. Rather less
soluble in Water. (Anthon.)
TUNGSTATB OF STRONTIA. 43
Tungsten and Barium.
A. TuNOSTATB OF Babyta. — a. Monotungstaie. — 1. Formed bj
precipitating a salt of baryta with monotungstate of potash or soda.-—
2. Bj boiling recently precipitated carbonate of baryta with hydrated
tnngstic acid [t. e.y with the precipitate produced by nitric acid in a solu-
tion of tungstate of soda]. — White powder, which emits a strong lights
and cakes together when ignited, without undergoing any loss of weight.
Decomposed oy the stronger acids, and also by potash or soda, both in
the wet and in the dry way. With boiling aqueous oxalic acid it forms
a solntion which beoomes turbid as it cools. Insoluble in water and in
boiling phosphoric a«id. (Anthoa.)
CalcQlatkm. Anthon.
W0> 1200 .... 6104 .... 61
BaO, W0» 196-6 Z 10000 Z 100
h, BUungstaU, — Formed by precipitating a soluble salt of bairta with
bitungstate of potash or soda. The hydrated precipitate is white, but
becomes yellowish after ignition, from loss of water. It does not dissolve
in cold water, and but very sparin^y in boiling water, so that the soln-
tion, on cooling, or on the aadition of sulphuric acid, becomes sliehtly
clouded It is partially dissolred when boiled with oxalic acid. (Anthon.)
J^tr ignUion, Anthon. Hfdrattd. Anthon.
BaO 76-6 .... 24-2 .... 2414 BaO.... 76-6 .... 21-18 .... 21
2WO» 2400 .... 76-8 .... 7586 2W0» 2400 .... 6637 .... 66
5HO.... 450 .... 12-45 .... 13
BaO,2WO* 316*6 .*.. lOO'O .... 100*00 +5Aq. 361*6 .... 10000 .... 100
B. SuLPH0*TUN08TATE OF Barium. — 1. Receutlv prepared tung-
state of baryta is diffused in water, and decomposed by hydrosulphuric
acid; the process goes on yery slowly. The lemon-yellow solution
yields, by spontaneous eyaporation, a yellow, transparent mass, of crys-
talline-laminated textore. — 2. Tersnlphide of tungsten is dissolyed in a
boiling aqueous solution of mono-hydrosulphate of baryta. Bi-hydrosul-
phate of baryta is decomposed but slowly, eyen at a boiling heat. The
yellow solution thus obtained dries up without any signs of crystallusation.
if it contains an excess of sulphide of tungsten, it leayes a brown yarnish.
(Berxeltus.)
Tungsten and Strontium.
A. Tungstate op Strontia. — a. J/bnofttwo'^tofe.— Preparation,
similar to that of the baryta-salt. Likewise anhydrous. White, soft to
the touch. When ignited, it emits a yiyid light, cakes together, and
becomes rongb and dense. It is insoluble in water, but yields, with
boiling aqueous oxalic acid, a solntion which becomes milky on cooling,
from u>nnation of a precipitate. (Anthon.)
CalcuIatloD. Anthon.
SrO 52 .... 30*23 .... 30
W0» 120 .... 69*77 .... 70 i
SrO, WO* 172 .... 10000 .... 100
ii
»
44 TUNGSTEN.
h. BUunggtate, — Prepared in a similar manner to the corresponding
salt of baryta. White powder, which loses water on ignition, and becomes
first grey, then bluish, then green, and lastly yellow. It is insoluble in
eold water, but dissolves completely in hot water and in aqueous phos-
phoric or oxalic acid. (Anthon.)
After ignition. Anthon. Hydnted. Anthon.
SrO 52 .... 17-81 .... 17-24 SrO .... 52 .... 1543 .... 15
2W0» 240 .... 8219 .... 8276 2W0» 240 .... 71-22 .... 72
5U0.... 45 .... 13-35 .... 13
SrO,2WO» 292 .... 10000 .... 100-00 +5Aq. 337 .... 10000 .... 100
B. SuLPHo-TUNGSTATB OF Strontittm. — SrS,WS'. — Monotungstatc of
strontia diffused in water is very readily decomposed by sulphuretted
hydrogen. The yellow solution thus obtained yields lemon-yellow, radiated
crystals on evaporation. If an additional Quantity of sulphide of tung-
sten is dissolved in the solution, it leaves a orown syrup on evaporation.
(Berzelius.)
TUNGSTSN AND CaLCIVM.
A. TuNGSTATB OF LiHR. — Found in nature as TuTiggten, Tungstate
of potash or soda precipitates chloride of calcium completely, even when
a slight excess of acid is present. (Anthon.) The precipitate is a white
powder. Tungsten belongs to the square prismatic system of crystalliza-
tion, and is found in two different square octohedrons, one more acute,
Fig. 21, and one less acute. Fig, 23. In the first, the e (above) : ^ (below)
= 130=^ 20'; in the ktter =113° 36'. (Hauy.) Specific gravity = 6-04.
(Karsten.) Harder than felspar; colourless and transparent. Before the
blowpipe, it fuses at the edges to a translucent glass. Dissolves readily
in borax, yielding a transparent glass, which, on cooling, rapidly becomes
milk-white and crystalline, and is not coloured in the inner fiame, even
after the addition of tin. With microcosmic salt, in the outer fiame, it
foi-ms a clear glass, which, when exposed to the inner flame, appears green
while hot, and blue after cooling; if tin is added, it assumes a still darker
green colour; but, after long exposure to the blast, with a sufllcient
quantity of tin, its colour becomes greenish yellow and continually paler,
because the tungsten is reduced. With carbonate of soda, tungsten forms
a white blistered slag, rounded off at the edges. (Berzelius.)
Hydrochloric or nitric acid extracts the base from powdered tungstate
of lime, separating yellow tungstic acid. A boiling solution of potash
removes tungstic acid from the powder. The salt is insoluble in water.
Berzelius. Bucholz & Brandes.
Tungiten.
Westmanland. 8di]ackenwalde. Zinnwsld.
CaO
28 .... 18-92
19-40 .... 19-06 .... 16-50
WO'
120 .... 81-03
80-42 .... 1800 .... 76-50
Impurities ....
• •■#
9-00 .... 5-54
CaO,WO» .... 148 .... 100-00 .... 9982 .... 9906 .... 98-54
B. SuLPHo-TUNGSTATR OP Calcium. — CaS,WS*. — Prepared in a similar
manner to the baryta compound. Forms a pale yellow, amorphous mass,
easily soluble in water and alcohol. With an excess of sulphide of tung-
sten, it yields a reddish brown, uncrystallizable compound, from the
solution of which ammonia throws down a light yellow powder. (Ber-
;|elius.)
TUNGSTEN WITH TANTALUM. 45
Tungsten and Magnesium.
A. TuNOSTATB OF Magnesia. — ^When tungstic acid and carbonate of
magnesia are boiled in water, tbe resulting solution yields, on evaporation^
small, brilliant scales, which are permanent in the air, readily soluble in
water, and have the same taste as other salts of tungstic acid. From a
solution of this salt, acids likewise precipitate a white substance, probably
a ternary compound.
B. SuLPHO-TUNGSTATE OF MAGNESIUM. — Prepared by the same me-
thod as the baryta-salt. The solution, which is readily oxidised in
the air, dries up in yacuo to a kind of yarnish, which readily dissolyes
both in water and alcohol. If the solution contains a larger quantity
of sulphide of tungsten, it yields, on eyapoiation, a brown amorphous
mass. (Berzelius.)
Tungsten and Cerium.
SuLPHo-TUNGSTATE OF Cbbium. — CeS,WS'. A solutiou of sulpho-
tnngstate of potassium gives a yellow precipitate with cerous salts; but
not till after the lapse of twenty-four hours. ^Berzelius.)
Tungsten and Yttrium.
TuNGSTATE OF Yttri A. —Formed when a salt of yttriais precipitated
by monotungstate of soda. White powder, containing 11*6 percent, of
water; its formula is therefore Y0,W0'-h2Aq. It is veiy sparingly
soluble in water, but rather more soluble in an aqueous solution of tung-
state of soda. (Berlin.)
Tungsten and Aluminum.
TuNOSTATB OF Alumina. — Monotuugstato of soda precipitates the
salts of alumina completely. (An then.)
The neutral salts of yttria, glucina, and alumina, are not precipitated
by a solution of sulpho-tungstate of potassium. (Berzelius.)
Tungsten and Thorinum.
TuNGSTATE OF Thorina. — Mouotuugstate and bitungstate of potash
or soda precipitate the salts of thorina in white flakes. (Berzelius.)
Tungsten and Tantalum.
Tantalous Acn> containing Tungsten ?-~ Obtained by reducing
tantaiic acid containing tungstic acid. Resembles pure tantalous acid, but
is much harder and denser^ and jeadily polished. (Gahn, Berzelius &
Eggertz.)
Tongsten and Tungsten.
A. TuNGSTATR OP TuNGSTOus OxiDE AND PoTASH. — Obtained in
a similar manner to the corresponding soda compound, (p. 47.) Small
46
TUNGSTBN*
needles^ copper-coloured, witli a tinge of Tiolet^ like sublimed indigo.
Yields a blue powder haying a coppery cast (Laurent, Ann. Chim, Phys.
67, 219.)
B. SuLPHO-TUirCWTATB OF PoTASSIUM WITH TuNOSTATS OP PoTASH.—
This compound is sometimes obtained in the preparation of sulpho-tungstate
of potassium. It is also formed bj fusing a mixture of monotnngstate
of potash with sulphur in a coyered crucible. The solution yields on
evaporation, lemon-yellow rectangular tables, containing 4*5 per cent*
of water of crystalhzation. If the water is expelled by heating the salt,
it becomes opaque and deeper in colour, and then fuses at commencing
redness, no decomposition taking place, provided the air is excluded.
When ignited in a current of hydrogen gas, it does not yield water.
Dissolves easily in water. The lemon-yellow solution is coloured reddish-
yellow or red by acids, and gives no precipitate either with salts of
protoxide of manganese or with alcohol. 100 parts of the anhydrous
salt yield, on analysis, 63*64 parts of tungstic acid, and 49*03 parts of
sulphate of potash, from which the following formula may be assumed as
nearly correct for the crystallized compound: KS,WS'-i-K0,W0'-|-4Aq.
(Berxelius.)
C. Fluoridb of Tungstbn and Potassium with Tungstate of
Potash.— ( Wolfram-Fluarkalium,) KF,WP»-|-K0,W0'-|-2Aq.— 1. Pot-
ash is added to hydrofluate of tungstic acid till a permanent precipitate
begins to appear. The solution is then evaporated to the crystallizing
point. In this process, half the potassium remains in the mother-liquor
as fluoride of potassium :
2(WO»,3HF) + 4KO =» KF,WI« + KO,WO»+2KP + 6HO.
-^2. Tungstate of potash is supersaturated with hydrofluoric acid.
2(K0, \V0') -h 4HF = KF,WF» -h KO,WO» + 4H0. The compound crjrs-
tallizes in large brilliant scales like boracic acid, permanent in the air,
and having a bitter and somewhat metallic taste. At a temperature a
little above 100^ these scales part with 4*58 per cent, of water and
become reduced to a fine powder. The powder fuses at a red heat and
without decomposition, provided aqueous vapour and silica are excluded :
but the platinum crucible acquires a reddish-orown colour from the action
of hydrofluoric acid. The fused compound solidifies on cooling to a pale
greenish mass. The crystallized salt dissolves with difficulty in cold, but
more readily in hot water; it is not decomposed after repeated solution
in water or aqueous hydrofluoric acid, and subsequent evaporation. (Ber-
zelius.)
Crystalliied; calculated aocordinf to Benelius.
Or:
KF
WF«
KO
... 57*9
... 1521
... 47*2
... 120*0
... 180
• •••
• ••■
■ ■••
14*65
38*49
11*94
30*37
4*55
2K
2W
4F
... 78-4
... 192*0
... 74-8
... 320
... 18*0
a...
....
....
....
• .#•
19*84
48-58
18*93
W0»
2Aq
40
2Aq
8*10
4*55
395*2
100-00
395*2
100*00
100 parts of the compound yielded in the analysis made by Berielius :
Potash 24*24, tungstic acid 59*57, hypothetically anhydrous fluoric acid
11*39, water 4-80.
D. Tungstatb op Tdngstovs Oxidb and Soda. — NaO,WO'
+ WO^WO'. Dry hydrogeu gas is passed over red-hot bitungstate of
ALLOYS OF TUNGSTEN. 4?
soda as long as water continues to be formed^ and tlie monotnngstate of
soda removed by solution in water. (Wbhler.) 100 parts of bitungstate
of soda thus treated, lose on the average 1*576 parts of oxygen, and yield
1*82 parts of water; or 2 atoms of the bitungstate of sodia lose one atom
of oxygen, and are resolved into one atom of monotungstate of soda and
the double salt : (Malaguti.)
2(NaO,2WO>) + H = NaCWO* + (Na0,WO3 + WO^ W0») + HO.
A golden-yellow, heavy powder remains undissolved, consisting of small
cubes which exhibit a perfect metallic lustre, even after pressure with the
burnishing steel on paper. When diffused in a state of fine powder
through water, it transmits light of a green colour. (According to Lau-
rent, it yields a blue powder.) It may be ignited in aelose vessel wi^ut
fusion or decomposition. (Wohler.)
C9k
aJataos.
Or:
Hali«ii1i. WofaUsr.
NaO....
31-2
.... 8-14
X^ w •••»•#«•
23*2
6*05
6-03 .... 6-60
W02....
112-0
.... 29-23
*W .•••
288-0
..,. 7516
•... 74-33 .... 73*89
2WO»
240*0
.... 62*63
90
720
.... 18*79
.... 19-64
383*2 .... 100*00 383*2 .... 100*00 .... 100*00
When ignited in the air, it assames a steel-grey colour on the surface,
fuses gradually (the change proceeding from the surface to the interior),
and yields a transparent mass of [ter?] tungstate of soda, which, on
cooling, forms an opaque whit« mass^ and protects the inner portions
of the double salt from oxidation. It behaves in a similar manner in
oxygen gas, exhibiting, however, a feeble combustion* It is decomposed
by chlorine at a red heat, with feeble emission of light, the products
being [tungstate of] chloride of tungsten which sublimes, and a mixture
of chloride of sodium with a large quantity of tungstic acid, coloured
green by tungstic oxide. By fusion with sulphur it is completely
resolved into sulpho-tungstite of sodium, (p. 42.) (Wbhler.) 100 parts
of the double salt fused with sulphur in a close vessel, yield 112*66
TOirts of sulphide of tungsten and sodium. (Malaguti.) 2(NaO,WO' +
W0», W0») -h 23S = 2(NaS, 3WS*) -h 9S0» ; hence, from one atom of
(NaO,WO'+ WO',WO') there results one atom of NaS,3WS'j the former
weighs 383-2, the latter 423*2; now 383*2 : 423.2 = 100 : 110*44, a
number which accords with the result of Malaguti*s experiment. The
double salt is decomposed and dissolved by hydrofluoric acid, but not by
other acids — not even by boiling aqua-regiaj — ^it is likewise unaffiBcted by
solutions of the alkalis. (Wohler.)
E. Fluoride op Tungsten and Sodium with Tungstate op
Soda.— NaF, WF» -f NaO, W0». Crystallizes less distinctly aad dissolves
more readily in water thaa the corresponding potsuwdum compound*
(Berzelios.)
Other Compounds of Tunosten.
With manganefie^ antimony, bismuth, tin, lead, iron, copper, and
silver; but not with gold or platinum. These alloys have a brown colour
and are generally brittle.
48
Chapter XIX.
MOLYBDENUM.
Scbeele. Optufc. 1, 200.
IlsemaDD. CrelL Ann. 1787^ 1, 407.
Heyer. Crell. Ann. 1787, 2, 21, and 124.
Hjelm. Crell. Ann. 1790, 1, 39;— 1791, 1, 179, 248, 266, 353 and 429;
2, 59;— 1792, 1, 260; 2, 358;— 1794, 1, 238.
Richter. Ueber die neuem Gegenstande der Chemie. 1, 49; 2, 97;
10, 86.
Hatchett PhU. Tramact. 1795, 323; also Crell. Ann. 1797, 1, 314, 417
and 498.
Bttcholz. Scher. J. 9, 485.— Also A. GeU. 4, 598.
-Brandea. Schw. 29, 325, and 331.
Berzelius. Schw. 22, 51. — Ann. Chim. Phys. 17, 5. — Pogg. 4,153. Pogg.
6, 331 and SSd.^Pogg. 7, 261.
Svanberg & Struye, Abhandlungen der Konigl, Acad, in Stockholm, 1848.
Also J. pr. Chem. 44, 257.
W<U8erblei, Molyhdiin, Molybdiinum, Molyhdine.
BisUny. Soheele in 1778 discoyered molybdic acid in a mineral
liitherto confounded Trith grapbite; Hjelm in 1782 prepared the metal
from molybdic acid. Berzelius described most of its chemical characters
and combinations.
Sources. In small quantity only as molybdic acid (molybdic ochre);
as sulphide of molybdenum (Wdsserblei) ; and as molybdate of lead
(Gelb-bleierz), The pig-iron, obtained in smelting the Mansfeld copper-
ore, contains from 9 to 28 per cent, of molybdenum. (Heine, J. pr.
Chem. 9, 204.)
Preparation. — 1. By exposing either of the oxides of molybdenum, or
molybdate of ammonia, or the acid molybdate of potash to a full white
heat in a charcoal crucible. The reduction is easily effected, and may
even be performed before the blowpipe on charcoal with carbonate of
soda; but to obtain a fused button of metal, a very strong heat is re-
quired. (Berzelius.) — 2. Hydrogen |as dried by means of chloride of
ciedcium, is passed over molybdic acid heated to whiteness in a porcelain
tube, till no more water is produced; the apparatus is then allowed to
cool, the current of hydrogen being kept up without intermission. (Ber-
zelius.)— 3. By exposing molybdic acid to the oxy-hydrogen blowpipe-
flame (Clarke);— or 4. Bv introducing it iuto the circuit of Children's
voltaic battery (Children).
MOLYBDOUS OXIDE. 49
. ' Pt'operties, The metal^ as prepared by the first method^ is silver-
white, with a strong metallic lustre^ and has a specific gravity of 7 '5
(Hjelm), 8*62 (Bucholz); when in small pieces it may be beaten out flat
withont breaking; it scratches an alloy of 8 parts silver and 1 part copper.
Fuses but impeifecUy in the most powerful blast-furnaces, so that it
has only been obtained in small masses. (Bucholz.)'^The molybdenum
prepared by the second method is an ash-grey powder, which remains
unaltered in the airj assumes metallic lustre by pressure; and conducts
electricity. (Berzelius.) That obtained by the third method is silver-white;
that obtained by the fourth, steel-grey.
Compounds of Molybdenum.
Molybdenum and Oxygen.
Molybdenum loses its metallic lustre by exposure to the air for some
days at ordinary temperatures; when heated in the air, it becomes first
brown, then blue, and lastly white; and — if the temperature is sufficiently
high — emits light, gives off fumes, and is converted into crystadlized
inolybdic acid. (Berzelius.) — On charcoal in the inner blowpipe-flame,
molybdenum is not altered; but in the outer flame it covers the charcoal
for a small space around, partly with transparent, brilliant, crystalline
scales, partly with powder of molybdic acid, which is yellow while hot
and becomes white on cooling. This coating may indeed be driven to a
greater distance by the action of the outer flame, but it leaves on the former
spot a portion of dark copper-coloured oxide of molybdenum. (Plattner.)
— When heated with nitre, molybdenum is rapidly oxidized; with hydrate
of potash, the action is slow, and attended with evolution of hydrogen
gas. (Berzelius.) — It decomposes aqueous vapour at a red heat, first form-
ing the blue oxide, and then molybdic acid. (Regnault.) — It dissolves in
nitric acid with evolution of nitrons fumes, and in hot oil of vitriol with
evolution of sulphurous acid. If the acids are used in small quantity
only, the metal is converted into molybdic oxide ; with a larger propor-
tion of oil of vitriol, the blue oxide is formed; and with a larger proportion
of nitric acid, the product is molybdic acid, which is also partially depo-
sited in the solid state. A mixture of nitric acid with sulphuric or hydro-
chloric acid rapidly oxidizes and dissolves the metal. An aqueous Solu-
tion of chlorine likewise oxidizes and dissolves molybdenum. Hydro-
fluoric acid, hydrochloric acid, dilute sulphuric acid, boiling solution of
potash, and water, do not exert any oxidizing power upon it. (Bncholz^
Berzelius.)
A. MoLYBDous Oxide, or Protoxide of Molybdenum. MoO.
Formation, All the metals which decompose water withdraw from
molybdic oxide and molybdic acid, in presence of one of the stronger
acids, such a quantity of oxygen that molybdous oxide is produced.
Preparaiion, Equal weights of mercury and hydrochlorate of molyb-
dic oxide dissolved in water containing free acid, are introduced into a
bottle, and liquid amalgam of potassium gradually added drop by drop;
as the action ceases, the liquid first becomes greenish, and afterwards
black and opaque. As soon as the molybdous oxide begins to separate,
and the potassium appears to be oxidized by the water, the solution is
VOL. ly. £
50 MOLYBDENUM.
decanted from the in6reaiy,-*«nd the blaok hydrate of molybdoni oxide
precipitated by ammonia^ then washed, dried oyer oil of yitriol in yacno,
and lastly ignited out of contact of air. If an excess of hydrochloric acid
were not present, hydrated bi-oxide of molybdenum would be thrown
down before it was conyerted into the protoxide, and would form a dark
brown instead of a blaok precipitate. — 8. A concentrated solution of
molybdate of ammonia, potash, or soda, is supersaturated with hydro-
chloric acid till the precipitated molybdic acid is re-dissolyed. The
solution is then digested with sine, by which it is first turned blue, then
reddish brown, and lastly black. It is then poured off from the sine, and
mixed with a quantity of ammonia just sufficient to precipitate the prot-
oxide of molybdenum alone. The hydrated protoxide is then collected on
a filter; washed, after the original liquid has passed through, with repeated
quantities of water containine ammonia, to remove the oxide of zinc
which is thrown down with it in small quantities; afterwards washed with
pure cold water; and lastly pressed, dried, and ignited as above. Portions
of oxide of zinc remain mixed with the molybdous oxide thus obtained.-*-
3. Fused or sublimed molybdic acid digested for a long time with hydro*
chloric acid and sine, is wholly converted into anhydrous molybdous
oxide, the merest trace only being dissolved. The molybdous oxide thus
obtained oxidizes rapidly in the air, probably because the oxygen easily
re-enters the pores trom which it has been expelled. During the oxida-
tion, the substance first assumes a purple and afterwards a hlue colour.
(Berzelius.)
Properties. Molybdous oxide prepared by the first and second methods
is pitch-black; that obtained by the third method is black, but when
exposed to the direct rays of the sun, exhibits a dark brass-yellow colour;
it takes the crystalline form of the molybdic acid £rom which it is
prepared.
Calculation,* aceordiiig to BeneUus.
Mo 48 85-71
8 14-29
MoO 56 .., 10000
MoO » 568-52 + 100 » 698*52. (Bendias.)
DeeompoHtions. By charcoal, and by potassium.
Combinations.— a. With Water. — Htdratbd Moltbbous Oxros.—
Prepared by precipitating the protochloride of molybdenum with ammo*
nia (vid, sup.); it may be washed in the open air, but must be dried in
vacuo; because, if exposed to the air during the latter operation, it assumes
a somewhat lighter colour, from incipient oxidation. It is black. When
heated in vacuo, it gradually parts with its water. The remaining anhy-
drous oxide, when heated nearly to redness, emits a vivid light, which,
however, lasts but for a moment. (Berzelius.)
* Svanberg & H. Strave (J. pr. Ch$m. U, 301) have determined the atomic
weif bt of molybdenum by fusing a given weight of molybdic add with carbonate of soda,
and obaerring the quantity of carbonic add expelled. The reanlts of three experiments
are 45848, 4612, and 45904. By a different process, however, viz., by igniting a
wdghed quantity of sulphide of molybdenum in moist, and afterwards in dried air, and
observing the increase of wdght, the atomic weight was found to be 46 '066 or 47*112:
(sulphur = 16-06.) But the errors inddental to this process, and indeed to every
other yet tried, render the atomic weight of molybdenum still a matter of uBoeitaiaty. f
MOLYBDIC OXIDE. 51
h, Anbydroiis moljbdoas oxide is insoluble in acids; the hydrate diffi-
onltly soluble. The Molybdous Salts in the solid state are dark grey
or black; their aqueous solutions are blacky or purple (especially if they
contain excess of acid)^ and nearly opaque; when largely diluted, how-
eyer, they are transparent and of a greenish brown colour. Their taste
is purely astringent^ not metallic. They oxidize less rapidly in the air
than the molybdio salts: consequently their aqueous solutions can be
more easily eyapomted without alteration. Hydrosnlphuric acid precipi-
tates from them brownish black sulphide of molybdenum, but not till
after some time. The caustic alkalis and their carbonates throw down
the black hydrated protoxide, which redissolyes in excess of carbonate
of ammonia, and sparingly in excess of carbonate of potash or soda.
Phosphate of soda precipitates brownish black molybdous phosphate.
Hydrosulphate of ammonia precipitates yellowish brown sulphide of
molybdenum, soluble in excess of the ammoniacal salt. If oxide of zinc
is present, it remains undissolyed in the form of sulphide of zinc. Ferro-
cyanide of potassium produces a dark brown precipitate, which dissolves
in an excess of the reagent, forming a dark brown solution. Ferricyanide
of potassium produces a reddish brown precipitate. Oxalic acid does not
affect molybdous salts.
IT Sesquiaxide of Molyhdenuvu Prepared, according to Kobell {J» t>r.
Chem. 41, 158; Pharm, Centr. 1847, 678), by boiling copper in a solution
of molybdic acid. IT
B. Molybdic Oxide or Bi-oxidb op Molybdenitm. MoO*.
Brown or VioUt^rown Oxide of Molybdenum of Bucholz.
Formatum and Preparation, — 1. By gently heating molybdenum for a
fthort time in contact with the air. (Bucholz.) — 2. Molybdous oxide takes
fire when heated in the air, burning with feeble glow, if free from oxide of
zinc, and is conyerted into molybdic oxide. (Berzelius.) — 3. By strongly
Igniting molybdate of ammonia in a covered crucible. (Bucholz.) — The
oxide obtained by this latter method is contaminated with molybdic acid,
which gives it a lighter colour; it may, however, be removed by solution
of potash or hydronuoric acid. (Berzelius.) — 4. Roasted sulphide of molyb-
denum is dissolved in aqueous solution of carbonate of soda; the mixture
evaporated to a small bulk; the solution filtered from the insoluble por-
tions, and evaporated to dryness; the residue ignited; the resulting
oolourless salt aissolved in water, which takes up foreign matters at the
same time; the solution again filtered, and evaporated to dryness; the
residue reduced to powder, and intimately mixed with half its weight of
sial-ammoniac; the mixture ignited in a closely covered crucible till the
sal-ammoniac is entirely expelled; the chloride of sodium dissolyed out
by water, and the molybdic acid by a boiling dilute solution of caustic
potash; and lastly, the molybdic oxide thrown on a filter, washed with
water, and dried. (Berzelius.)
Properties. Molybdic oxide, as prepared by the fourth method, is
brownish black while moist; dark brown when dry; and of a brilliant
purple colour in direct sunshine (Berzelius); the third method yields it
in dark, copper-coloured, crystalline scales, having the metallic lustre,
and ol specific gravity 5-666. (Bucholz.)
e2
52 MOLYBDENUM.
Calculation. Beraeliiu. Buckolz.
MO 48 .... 75 .... 75 .... 73
20 16 .... 25 .... 25 .... 27
MoO» 64 Z Too Z. 100 Z. 100
(MoO^ =: 598-52 + 200 = 798*52. BeneUus.)
Decompositions, — Reduced to tlie metallic state by charcoal and potas-*
Slum. According to Berzelius, it remains unaltered after ignition in an
atmosphere of dry chlorine gas.
ConiUnations, — a. With Water.— «. Hydrated Moltbdic Oxidb
of Bucholz. — 1. An aqueous solution of bichloride of molybdenum is
precipitated by ammonia. — 2. A concentrated solution of molybdic acid
in hydrochloric acid is digested with finely divided molybdenum till the
liquid, which first assumes a blue colour, becomes dark red; the oxide is
then precipitated by ammonia. — S. Molybdic acid is digested with
hydrochloric acid and copper, till it is entirely dissolyed; and the
resulting hydrochloric acid solution of molybdic oxide and oxide of copper
is roixea with a large excess of ammonia, by which the oxide of copper
is redissolved. The molybdic oxide is then washed with water con-
taining ammonia. The precipitate should be washed on the filter, first
with solution of sal-ammoniac, and afterwards with alcohol, the solvent
action of which is much less than that of pure water. The oxide is then
pressed out and dried in vacuo over oil of vitriol, to prevent oxidation.
The hydrated oxide is reddish brown when recently precipitated, but
blackish brown after drying. When ignited in vacuo, it leaves the
anhydrous brown oxide. By exposure to the air it becomes darker, from
formation of blue oxide, and acquires a certain degree of lustre. From
this substauce water dissolves out the blue oxide, together with portions
of the brown oxide, forming a green solution and leaving hydrated
molybdic oxide in a state of greater purity. (Berzelius.)
p. Solution op Molybdic Oxide. — The hydrate dissolves slowly
and in small quantity only, in pure water. The solution is yellow, or
when fully saturated, dark red; reddens litmus; has a slightly rough and
afterward^ somewhat metallic taste; and deposits the hydrate on the
addition of sal-ammoniac or some other salt. When kept for several
weeks in a stoppered bottle, it becomes gelatinous, but does not lose its
transparency. When spontaneously evaporated in the air, it first gela-
tinizes, and then dries up to a brownish black hydrate which is no longer
soluble in water, but yields up the blue oxide which has been produced
from it. (Berzelius.)
b. With Acids forming the Molybdic Salts. — The bi-oxide, after
ignition, is insoluble in all aqueous acids, traces only being dissolved by
boiling oil of vitriol and by a boiling solution of cream m tartar; after
which no more is taken up, even if the oxide be digested in fresh acid.
It dissolves but slowly in fused bisulphate of potash or soda. The
molybdic salts are therefore prepared either by dissolving the hydrated
oxide in acids, or by digesting an excess of molybdenum in the acid in
which it is to be dissolved, and adding dilute nitric acid, drop by drop'
(excepting when a nitrate is to be formed), till the other acid is saturated
with molybdic oxide; or by digesting an excess of molybdenum with
molybdic acid and the acid which is required to dissolve the oxide when
6L1VE-GREEN OXIDE, 53
formed, — ^hydrochlorio acid, for example, — ^till the bliie colour first pro^
daced is converted into a reddish brown; or lastly, by digesting molybdio
acid with copper and hydrochloric acid, which, in that case, dissolves
oxide of copper and molybdic oxide together. The salts of molybdic
4>xide, in the anhydrous state, are almost black ; but when hydnited,
they are red, and yield reddish brown solutions with water. They have
a rough, somewhat acid, and subsequently metallic taste. Their aqueous
solutions, when heated in the air, have a tendency to become blue by
oxidation. With zinc they first blacken, and then yield a black precipitate
of hydrated molybdons oxide. Hydrosulphuric acid gives a precipitate of
brown sulphide of molybdenum, but not till after some time. With am«
monia or potash, they yield a rusty brown precipitate, insoluble in excess
of the alkali. If the quantity of ammonia added is insufficient for satu-
ration, the precipitate re-dissolves in the liquid, and if the solution is
veiy dilute, it does not appear till after the addition of sal-ammoniac, by
which the solubility of the hydrated oxide in water is destroyed. The
carbonates of potash and soda produce the same precipitate, which, how-
ever, is soluble in excess of the reagent. Phosphate of soda gives a
brownish white precipitate. Hydrosulphate of ammonia throws down
yellowish brown sulphide of molybdenum, soluble in excess of the ammo-
niacal salt. Ferrocyanide or ferricyanide of potassium gives a dark
brown precipitate, insoluble in excess of the precipitant. Tincture of
galls imparts to salts of molybdic oxide a deep reddish brown colour, at
uie same time producing a scanty greyish brown precipitate. Oxalic
acid causes no precipitation. The insoluble molybdic salts are rapidly
decomposed in the air, when covered with solution of caustic potash or
soda, an alkaline molybdate being formed. (Berzelius.)
Between the above described brown oxide and molybdic acid, the
olive green oxide and the blue oxide must be interposed according to
their proportions of oxygen : these compounds, however, should perhaps
be regarded not as distinct oxides, but as compounds of the brown oxide
with dififerent quantities of molybdio acid*
OUve^reen Oxide,
1. If 2 parts of powdered molybdenum are digested in a stoppered
bottle, at a temperature between 40^ and 60^, with one part of molybdio
acid and a very large quantity of water, a liquid is obtained after some
days, which at first appears oark blue, then dark green, and afterwards
undergoes no further change. From this solution, powdered sal-ammoniac
completely precipitates the green oxide, which, however, redissolves in
pure water. — 2. When a mixture of the brown and blue oxides of
molybdenum is dissolved in hydrochloric acid, ammonia throws down
from the solution a similar green precipitate, which may be washed with
water containing sal-ammoniac, but from which pure water dissolves out
the blue oxide, leaving the brown oxide in the state of hydrate. (Ber-
zelius.) This oxide, according to Berzelius, is identical with the lighi
blue oxide which Buoholz obtained by digesting the blue oxide with finely
divided molybdenum and water*
Blue Oxide; Buchoh*s Molyhdenow acid.
FcmuUion and Preparation,^^! . Molybdenum, the protoxide, or the
brown oxide is heated in the air, but not for a very long time. — 2. Molyb-
H MOLYBDENUM.
denum, or hydraied molybdie oxide, is moistened witli water and exposed
to the air for a considerable time, or boiled with water in an open yessel.-^
3. A mixture of 4 parts of molybdie acid with 2 parts of molybdenum, or
with 3 parts of the brown oxide, is reduced to a fine paste with a small
quantity of water, a gentle heat being applied. The mixture is then boiled
with water; the clear liquid poured off; and the insoluble portion aeain
rubbed up in a mortar and boiled with a fresh quantity of water. The blue
solutions thus obtained are then evaporated out of contact of air, or in con-
tact with molybdenum. (Bucholz.)-->4. An aqueous solution of bimolybdate
of ammonia is mixed with a solution of bichloride of molybdenum — where-
upon the liquid immediately becomes blue and deposits the blue oxide;
this is collected on a filter. If the bimolybdate of ammonia be added in
excess, the solution which passes through the filter is of a light-blue
colour; but if the bichloride of molybdenum predominates, the filtrate is
green. The hydrated oxide on the filter is washed, first with water con-
taining sal-ammoniac, which acquires but a slight colour, and then with
alcohol or cold water, which, however, dissolve it in larger quantity; it is
lastly dried in the air, as it is not liable to become oxidized. (Berselius.)
The hydrated oxide prepared by either of the aboye methods may be
rendered anhydrous by ignition in vacuo. (Berzelius.)
The oxide is nearly black after ignition. (Berzelius.)
As the blue oxide is produced by the double decomposition of bimolyb*
date of ammonia and bichloride of molybdenum, it must be a compound of
1 atom (18 per cent.) of molybdie oxide, and 4 atoms (82 per cent.) of
molybdie acid.
2(NH», 2MoO>) + MoO», 2HC1 « 2(NH», HCl) + MoO», 4MoO».
In fact, the analysis by ammonia gives this proportion. (Berzelius.)
Decompositions. Ammonia or potash dissolves out molybdie acid from
the hydrate, and leaves molybdie oxide (a yeir dilute alkaline solution
dissolves the whole compound and does not deposit the molybdie oxide
till it is boiled) ; hence molybdenous acid does not form salts. The
stronger acids act in a similar manner on the ignited oxide. (Berzelius.)
Cotnbinations, — a. With Water.
«. Hydrate of the Blue Oxide. — Prepared by either of the four methods
given above. Dark blue powder, resembling powdered indigo, having a
bitter, rough, metallic taste, and reddening litmus strongly. (Bucholz.)
p. bolxUion of the Blue Oxide, — The ignited oxide imparts to water
only a slight blue colour. The hydrate dissolves ver^ abundantly in
water, especially in hot water, and nothing is deposited on cooling.
From the intensely dark blue solution, which, when highly concentrated,
is of a syrupy thickness (Bucholz), sal-ammoniac precipitates nearly all
the hydrate, though the supernatant liquid still retains a lifht blue colour.
When evaporated in the air, it becomes lighter coloured &om oxidation.
(Berzelius.)
h. With Acids, forming salts whose base is a compound of molybdie
acid and molybdie oxide. Acids form with the blue oxide dark blue
solutions, which, when evaporated, yield dark blue masses of the consist-
ence of syrup or extract, and on exposure to the air, lose their colour by
oxidation, especially when heated. Potash decolorizes the blue solution,
and precipitates hydrated brown oxide ; when largely diluted, however,
the liquid remains blue ; sal-ammoniac precipitates some of these solutions
only. (Bucholz, Berzelius.)
c. The blue oxide is sparingly soluble in alcohol.
r
MOLTBDIC ACID. 55
C. MOLYBDIC AoiD. MoO'.
Found native as Molyhdic Ochre,
FomuUion, — 1. Bj exposing molybdenum, or ita lower oxides, or
sulphide of molybdenum, to long continued heat in the air. — 2. By the
action of nitre on the same substances.— -3. By igniting the metal or its
oxides in an atmosphere of aqueous Tapour. (Regnault, Ann. Chim. Phys,
«2, 356), or with hydrate of potash (Liebig, Katin, Arch, 2, 57), in which
case, hydrogen gas is likewise evolved.
PreparixtUm,'—*^ . Molybdenum or one of its lower oxides is dissolved
in excess of nitric acid, and (a) the solution either evaporated to dryness,
and the residue ignited; or (6) left to evaporate spontaneously, and the
molybdlo acid — which in this case is deposited as a white powder — coU
lected on a filter, purified with water, and dried. (Berzelius.) — 2. Sul-
phide of molybdenum is digested with nitric acid till it loses its grey
colour ; the mixture is then evaporated, and the molybdic acid produced
is freed from the adhering nitric and sulphuric acids by washing with
water. (Scheele.)— 3. Finely divided, pure native sulphide of molybdenum
is roasted — at a strong heat at first, but afterwiurds at a lower tempe-
rature — till it appears yellow while hot and white on cooling. — 4. From
impure sulphide of molybdenum mixed with quartz, &c., it is necessary
first to prepare molybdate of ammonia, (g. i;.) The salt is then heated
for a long time in an open crucible, at a temperature low enough to
prevent fusion. TBerzelins.) The molybdate of ammonia prepared from
the native molybdate of lead may likewise be used for this purpose.
(Wittstein.)
Properties, — As prepared according to (1, 6.) White, bulky, porous
mass, difiusing itself in water in small, silky, crystalline scales: after
ignition, by which it loses nothing but 2 per cent, of pure water, it
appears white and soft like talc ; after fusion, it forms greyish or yellow-
ish white radiated masses; or, after sublimation, brilliant, colourless,
transparent laminae or needles. Its specific cpravity is 3'46. (Bergman.)
It assumes a lemon-yellow colour every time it is heated. Fuses at a red
heat (and more readily when it contains alkali) to a brownish yellow liquid;
in covered vessels it volatilizes at high temperatures only, but when
exposed to the air, even at its melting point, it volatilizes in white fumes,
which condense above the fused acid in the form of a crystalline sublimate.
Has a sharp metallic taste, and reddens litmus. Volatilizes when exposed
on platinum wire to the blue flame of the blowpipe, imparting to it a
yellowish-green tinge. ^Plattner.) In the inner flame, it first becomes
blue and then brown ; if heated on charcoal it fuses and is absorbed ; but
is reduced by a powerful blast to finely divided metal which sinks in the
pores of the charcoal ; it may be separated by washing away the lighter
particles with water. (Berzelius.)
Calculatioii. Berzelius. Bucholz.
MO 48 .... 66'7 .... 66-613 .... 67 to 68
30 24 .... 33-3 .... 33-387 .... 33 „ 32
MoO» 72 Z 1000 Z 100-000 Z 100 lOo"
(MoO" = 598-52 + 3. 100 = 898-52. BcrzeUw.)
DecomposUums, — I. Reduced to the metallic state by ignition with
potassium or sodium (with vivid incandescence), or with charcoal ; in a
56 MOLYBDENUM.
current of hydrogen gae ; in the oxy-hydrogen blowpipe flame ; and by a
powerful current of ffalvanio electricity. — 2. To molybdous oxide: by
digestion with hydrochloric acid and amalgam of potassium, zinc, or other
metal capable of decomposing water. — 3. To the state of brown oxide:
by ignition in combination with ammonia^ or by digestion with hydro-
chloric acid and molybdenum or copper. — 4. To the state of blue oxide :
by a small quantity of hydrosulphuric acid in presence of water or on
exposure to heat, the action being attended with separation of sulphur ; by
sulphurous acid, with production of sulphuric acid ; by aqueous hydriodic
acid, with separation of free iodine, and formation of a liquid which is
green at first, but afterwards becomes blue ; by boiling hydi<>chloric acid,
with disengagement of chlorine; by nitric oxide in presence of water, with
formation of nitrous acid (Kastner, Kaatn, Arch. 26, 465); by protochloride
of tin, with formation of bi-oxide of tin; by digestion with water and with
metallic molybdenum. — 5. To sulphide of molybdenum : by hydrosulphuric
acid in excess, in presence of water, or when aided by heat. Molybdic
acid is not affected by fusion with metallic molybdenum. (Berzelius.)
Combinations, — a. With Water. — Aqueous Moltbdic Acid. — Molyb-
dic acid dissolves, according to Bucholz, in 500 parts of cold water, and in
a much smaller quantity at a higher temperature: according to Hatchett, it
requires 960 parts of hot water. The solution yields a red precipitate with
ferrocyanide of potassium^ but not till one of the stronger acids is added.
b. With the stronger acids. The affinity of molybdic acid for other
acids is very feeble. After ignition, it is but slightly soluble in a
boiling aqueous solution of cream of tartar; before ignition, however, it
dissolves in some of the other acids. The solutions thus obtained are
sometimes colourless, sometimes yellow or brownish. By metallic zinc
or tin, they are first turned blue, then green, and lastly black, molybdous
oxide being precipitated ; by digestion with copper, they become dark
red. Protochloride of tin produces a greenish-blue precipitate, which
dissolves in hydrochloric acid, forming a green solution. Hydrosulphuric
acid in small quantity colours them blue; in larger quantities it produces
a blackish brown precipitate (a mixture of bisulpnide of molybdenum
with sulphur : Berzelius). The supernatant liquid is green, and deposits
after long standing, or more rapidly when heated, a further quantity of
brown sulphide of molybdenum ; a small quantity of molybdenum, how-
ever, still remains in the solution. If the liquid contams but a very
small quantity of molybdic acid, it forms with excess of sulphuretted
hydrogen, a green solution, which deposits brown sulphide of molyb-
denum only after long standing or when heated. Hydrosulphate of
ammonia behaves in a similar manner to hydrosulphuric acid. (Bucholz,
Berzelius.) Ferrocyanide of potassium produces a dense, reddish-brown
precipitate, soluble m excess of the reagent and also in ammonia. (Ber-
zelius.) Ferrocyanide of potassium gives a somewhat lighter coloured
precipitate, which is likewise soluble in ammonia. (H. Rose.) Tincture
of galls throws down a green precipitate, (Smithson.)
e. With Salifiable Bases, forming the Salts op Moltbdic Acid,
MoLYBDATRs. Molybdic acid expels carbonic acid from solutions of the
alkaline carbonates. It chiefly forms salts containing one or two atoms
of acid. The salts are generally colourless or yellow; when soluble,
they have a faint metallic taste. They are fixed in the fire, unless the
base is volatile. The addition of a very small portion of concentrated
I
MOLYBDENUM AND BORON. 6?
eulphurie^ hydroobloric, or nitric acid to a salt of molybdic acid mixed
with a small quantity of water, causes th^ separation of white, curdy
molybdic acid, which is soluble in a slight excess of either of the three
acids, or in a large quantity of water; phosphoric acid and oxalic acid do
not produce this effect. 7 According to Svanberg & Struve, when phos*
phoric acid or a liquid containing it is added to a solution of an alkaline
molybdate, together with an excess of hydrochloric acid, the mixture turns
yellow, and after some time deposits a yellow precipitate. (Gmelin has
likewise obsenred this effect in the case of molybdate of ammonia.) This
reaction is stated to be so delicate, that it may be employed for the detec*
tion of phosphoric acid. (J. pr. Chem. 44, 257.) IT The molybdates, when
supersaturated with a stronger acid, yield, according to Berzelius, the same
results as those just described under 5. The molybdates (molybdate of
ammonia^ but not the potash salt : Gmelin), heated with oil of vitriol, form
a blue mass, either immediately or after cooling. (Smithson.) When
heated on charcoal in the inner blowpipe flame with carbonate of 6od%
these salts yield metallic molybdenum, or an alloy of molybdenum with
the metal existing in the base. With borax and microcosmic salt, they
give a brown colour in the inner flame. The compounds of molybdic acid
with the fixed alkalis, when mixed with sal-ammoniac and ignited, yield
molybdic oxide, together with chloride of the alkali-metal, which latter
may be extracted by water. (Berzelius.) The alkaline molybdates in solu-
tion, give, with a small quantity of protochloride of tin, a blue colour ;
with a larger quantity, a dingy blue precipitate which dissolves in oil of
vitriol, producing a splendid blue solution ; with a stiU larger proportion
of the tin-salt, the precipitate is of a dull green colour, and yields with
oil of vitriol, a beautiful green solution. The molybdates of ammonia,
potash, and soda, are the only salts of molybdic acid that dissolve readily
in water ; of the rest, some dissolve with difliculty, and others are com-
pletely insoluble. The aqueous solutions of the more soluble alkaline
molybdates are coloured yellow by bydrosulphuric acid, from formation of
a double sulphide of molybdenum and the alkali-metal, [MS,MoS'] and
then yield with acids a brown precipitate of tersulphide of molybdenum.
They give white precipitates with the salts of the earthy alkalis and of
the earths, and precipitates of various colours with those of the heavy
metals: e.g. white, with salts of lead or silver; yellow with ferric salts;
and yellowiBh white with mercurous salts. (Berzelius.) With tincture of
galls they give, according to Smithson, a reddish yellow precipitate which
turns green on the addition of an acid. [The mixture is dark reddish
brown but transparent; the addition of a drop of hydrochloric acid causes
the separation of a dense, dingy brown precipitate, which, by a larger
quantity of acid, is converted into small reddish brown flakes.]
None of the oxides of molybdenum combine with carbonic acid.
(Berzelius.)
Molybdenum and Boron.
A. Borate of Moltbdocs Oxtdb. — Dark grey precipitate, which
turns black on drying, is insoluble in water, and dissolves but sparingly
in aqueous solution of boracic acid. (Berzelius.)
B, Borate op Molybdic Oxide. — a. Bichloride of molybdenum
gives with borate of ammonia a rusty-yellow precipitate, insoluble in
water. — &. Hydrated molybdic oxide dissolves in boiling boracic acid,
56 MOLYBDENUM.
yielding a yellow eolation which, when evaporated, solidifies to a jelly,
and deposits the nentral salt. (Berzelins.)
C. Borate of Moltbdio Acid. — ^An aqneons solution of boracio
acid dissolves molybdic acid on boilinff, and when the latter is in excess,
forms with it an opaque viscid liquid of the consistence of turpentine.
The solution becomes milky as it cools, and yields a colourless filtrate
which on evaporation deposits colourless crystals, decomposable by alcohol
into a yellow powder and boracic acid (containing a very small quantity
of molybdic acid, which dissolves in the menstruum). (Berzelins.)
MOLTBDENUM AND PHOSPHORUS.
A. Phosphide of MoLTBDEirirM.— Prepared by Pelletier, but not
further examined.
B. Phosphate of Molybdous Oxide. — a. DiphosphaU. Formed
when protoohloride of molybdenum is precipitated by ordinary diphos-
phate of soda. Dark grey precipitate, soluble in excess of protoohloride
of molybdenum.
h. Add Phosphate, — The solution of the hydrated protoxide in aqueous
phosphoric acid jields on evaporation a dark purple, syrupy mass, which
IS deliquescent and dissolves in ammonia, forming a blackish brown solu-
tion, (berzelins.)
"^
C. Phosphate of Molybdic Oxide. — a. Monophosphate. — Ordinary
diphosphate of ammonia, added to a solution of the bichloride of molyb-
denum, throws down liffht red flakes, while the liquid itself remains
yellow in consequence ox a portion of the salt being dissolved.
6. Acid phosphate. — A saturated solution of hydrated molybdic oxide
in aqueous phosphoric acid, dries up by spontaneous evaporation to a
transparent, red, tenacious, uncrystallizable mass, which dissolves in
ammonia with a red colour, but separates again almost entirely in the
course of an hoar. (Berzelius.) — Bucholz obtained a similar compound
by heating a mixture of molybdenum and phosphoric acid for a long
time, the heat being raised to redness toward the end of the process: it
forms a greyish-blue mass having a very acid and subsequently metallic,
astringent taste. It dissolves in water, forming a yellowish-brown
solution.
D. Phosphate of Molybdic Acid. — a. Basic Phosphate. — Molybdic
acid, digested while still moist with a small quantity of aqueous phos-
f boric acid, yields a lemon -yellow salt insoloole in water. (Berzelins.)
For the action of phosphoric acid on molybdic acid in combination, vid,
p. 57.]
^ 6. Acid Phosphate. — ^With a larger proportion of aqueous phosphoric
acid, the salt a, which is first product, dissolves on the application of heat,
and forms a colourless liquid, which yields, on evaporation, a tenacious,
uncrystallizable, transparent mass, having a very rough taste, and readily
soluble in water and alcohol. The alcoholic solution is yellow, but turns
blue on evaporation, and leaves a brown opaque residue, which again
dissolves in water, forming a bine solution. (Benelius.)
Bucholz. Brandes.
Seybert.
60 .... 59*6
•••»
59-42
40 .... 40-4
.•••
39*68
SULPHIDES OF MOLYBDENUM. iifi
MOLTBDBNUM AND SuLPHUR.
A. Bisulphide of Molybdekum. — Molybdous Sulphide, Sulpho-mo-
lyhdotiB Acid, — Found native as Was»erblei or Molyhdenum-glance, Tbe
residue obtained when the higher salphides of molybdenum are heated.
Likewise produced bj igniting molybdic acid with sulphur. The native
variety belongs to the hexagonal sj^stem of crystidlisation (B, a. I,
16); Pig. 185 and 138. Cleavage distinct parallel to p. Sp. gr. s 4*6.
Softer llian calcspar. Soft and unctuous to the touch. Bluish grey, with
metallic lustre. Leaves a greenish streak on porcelain. The artificial
compound is a black shining powder.
WoMterhhi,
Mo 48 .... 60
^S 32 .... 40
MoS» 80 !I] 100 ~. 100 ~7.. lOO'O ~, 9910
In close vessels it sustains a high temperature without fusing or under-
going any change, and, according to H. Rose, is not decomposed by igni-
tion m dry hydrogen gas. When heated in the air it is converted into
Inolybdic acid, with evolution of sulphurous acid.
Before the blowpipe on charcoal it gives off sulphurous acid, cover-
ing the charcoal with a yellowish-white incrustation; but it bums with
great difficulty, and the combustion is but imperfect. (Berzelius.) On
platinum wire it colours the outer blowpipe flame green. (Kobell.) It
colours a bead of borax mixed with nitre, dark-brown in the inner flame,
and light-brown in the outer.
It decomposes yapour of water at a red heat slightly, but at a higher
temperature with greater facility. (Regnanlt.) Detonates with nitre,
forming molybdate of potash. Dissolves readily in warm aqua-regia,
producing molybdic and sulphuric acid. Easily oxidized by nitric acid.
Dissolves in boiling oil of vitriol with evolution of sulphurous acid, and
forms a blue solution. (Berzelius.) [For its behaviour with oxide of lead
at a red heat, vid. BerUiier^ Ann. Ohxm. Fhys, 89, 251.]
Tersulphidb of Moltbdenitm. — Molybdic Sulphide^ Sulpho^molyhdic
acid. — Formed by the decomposition of molybdic acid by hydrosulphuric
acid. — 1. A concentrated solution of a salt of molybdic acid is saturated
with hydrosulphuric acid; a stronger acid added in excess; and the
precipitate digested with it for some time, in order to decompose any
alkaline hydrosulphate possibly thrown down with it, and then purified
with water: the water howeyer redissolves a small portion. — 2*. The
solution of molybdic acid in an alkaline bihydrosulphate (MS,HS) is
precipitated by a stronger acid. — The sulphide of molybdenum thus
obtained is likely to be mixed with sulphur or molybdic acid. In the
moist state, it appears reddish brown, but when dried it forms a blackish
brown powder, wnich also leaves a blackish brown streak on porcelain or
paper. (Berzelius.)
Mo
3S
I... 4o
48
Calculation.
60
50
....
Berzelius.
49*72
50*28
MoS»
96
.••*
100
....
100-00
iSO MOLYBDENUM^
When heated in a close vessel it loses the third atom of sulphur, and
is converted into bisniphide of molybdenum, having a powerful metallic
lustre. Exposed to the air in a moist state, it forms a small quantity of
sulphuric acid, which disintegrates the filter-paper. It dissolves with
diiiiculty-— except when boiled — in a concentrated solution of potash, and
is partially decomposed into KS, MoS^. It is somewhat soluble in water,
especially in hot water, yielding a dark-yellow solution. (Berzelius.) —
The liquid may likewise be reguded as containing MoO*, 3HS.
Tersulphide of molybdenum unites with the more basic metallic
sulphides, forming StUpko-molyhdaUs, or Molyhdo-wlphites. For one
atom of the basic sulphide they contain from 1 to 3 atoms of tersul-
phide of molybdenum. — a: The coinpounds of this nature which are
soluble in water are obtained: 1. By passing hydrosulphuric acid through
a concentrated solution of a salt of molybdic acid, and evaporating.
If the solution is dilute, the absorption takes place more slowly.
KO,MoO*+4HS = KS,MoS* + 4HO. The liquid assumes a yellowish
red, or, when iron is present, a reddish-brown colour. — 2. By dissolving
tersulphide of molybdenum in an aqueous solution of a metallic sulphide
(or alkaline hydrosulphate). If an alkaline bihydrosulphate is used, the
act of solution is attended with disengagement of hydrosulphuric acid,
and takes place but slowly, unless heat is applied. By boiling bisulphide of
molybdenum and sulphur in the aqueous solution ot an alkali, especially
a solution of baryta, strontia, or lime, an alkaline bisulphide is first formed,
and then a compound of a protosulphide of the alkali-metal with tersul-
phide of molybdenum.— 6. The insoluble compounds are prepared by
Erecipitating the soluble compounds with salts of the earths and of the
eavy metals.
The compounds soluble in water are crystallizable, and in that state
often appear green by reflected, and red by transmitted light; the rest
have a fine red colour; but an excess of sulphide of molybdenum makes
them darker, and the presence of iron renders them brown.
The sulpho-molybdates are either wholly or for the most part decom*
posed when ignited out of contact of air; the basic metallic sulphide
either combining with the third atom of sulphur in the sulphide of molyb-
denum, when capable of so doing, and producing a mixture of bisulphide
of molybdenum and another metallic bisulphide removable by water (as
with potassium or sodium, in which case, however, the decomposition of
the compound, even at a strong red heat, is but imperfectly effected) : or
the third atom of sulphur escapes in the form of vapour, and leaves a
mixture of bisulphide of molybdenum with the other metallic proto-
sulphide.
Only the compounds of tersulphide of molybdenum with the sulphides
of the alkali-metals and of magnesium, are soluble in water. The solu-
tions are red, inclining to brown if the sulphide of molybdenum is in
excess; but reddish yellow if the other metallic sulphide predominates.
(These solutions may also be supposed to contain a double hydrosulphate;
for example, in the potassium compound, by the decomposition of 4 atoms
of water: KO, HS-fMoO*, 3HS.) If the solutions are boiled for some
time in close vessels, they deposit— especially when the tersulphide of
molybdenum is in excess— bisulphide of molybdenum, and a compound of
the basic sulphide (or sulphur-base), with tetrasulphide of molybdenum:
hydrosulphuric acid is evolved at the same time. The solutions of these
compounds remain tolerably stable in the air, provided they are concen-
trated, and contain more than one atom of tersulphide of molybdenum to
TETRASULPHIDE OP MOLTBI>ENUM, 61
one atom of the sulphur-base. But if the sulphide of the alkali-metal (or
alkaline hydrosulphate) predominateSi or if free alkali is present, or if
the solution itself is dilute, it gradually becomes darker, from forma-
tion of an alkaline hyposulphite and a compound of the sulphur-base
with excess of tersulphide of molybdenum. The latter substance is then
decomposed, though very slowly, with separation of tersulphide of molyb-*
denum; and the supernatant liquid which is blue, contains alkali, partly
in combination with acids of sulphur, partly with molybdic acid and blue
oxide of molybdenum. Acids added to these aqueous solutions precipitate
tersulphide of molybdenum, and liberate sulphuretted hydrogen. Metallic
oxides which readily part with their oxygen, produce in these solutions a
molybdate of the alkali and a new metallic sulphide, which enters into
combination with the un decomposed portion of the tersulphide of molyb-
denum. (Berzelius.)
0. Tbtrasulphide of Molybdenum. — Fersulphomolt/hdic Add,
Peratdphide of Molybdenum of Berzelius. — Bimolybdate of potash is satu-
rated with hydrosulphuric acid, and the nearly black liquid — which con-
tains KS, MoS' in solution, and a compound of KS with excess of MoS'
diffused through it — is boiled in a retort for some hours — whereby hydro-
sulphuric acid is expelled and the precipitate increased. The solution
when cold is filtered, and the black powder of bisulphide of molybdenum
separated as completely as possible by levigation, from the heavier red
crystalline scales of tetrasulphide of molybdenum, combined with sul-
phide of potassium. The latter compound is collected on a filter and
washed with cold water, till the filtrate no longer e^ves a blackish
brown, but a pure red precipitate with hydrochloric acid. The red scales
remainiufi; on the filter are then treated with boiling water, which leaves
an insoluble residue of bisulphide of molybdenum; the dark red solution
obtained is precipitated by hydrochloric acid in excess; and the precipi-
tated tetrasulphide of molybdenum is thrown on a filter and purified by
washing with water. (Berzelius.)
Recently prepared tetrasulphide of molybdenum presents the appear-^
ance of a dark red, translucent, bulky precipitate; it shrinks up consider-
ably when dried, and forms a grey, coarsely granular mass, having a
metallic lustre, and yielding a cinnamon-brown powder when ground up
with water. (Berzelius.)
Calculation. Berzelius.
Mo 48 .... 42-86
4S 64 .... 57-14 .... 560 to 55'8
MoS< 112 .... 10000
When distilled alone, it yields a small quantity of sulphurous acid and
water (whence, also, Berzelius in his analysis obtained too small a quan-
tity of sulphur), and then sulphur; leaving bisulphide of molybdenum*
It is not decomposed either by boiling water or by acids. (Berzelius.)
Tetrasulphide of molybdenum combines with the more basic metallic
sulphides, forming Fer-gutphomolyhdates or Molyhdo-persulphUes,
Preparation. — 1. By the method given for that of tetrasulphide of
molybdenum {yid, supra), — 2. When bisulphide of molybdenum in excess
is boiled with a concentrated solution of potash and the mixture filtered
after cooling, a slightly coloured solution is obtained; and a mixture of
bisulphide of molybdenum with per-sulphomolybdate of potash (KS, MoS^)
62 MOLTBDINUU.
remains on the filter; the latter may he separated by solution in boiling
water. — 8. By double decomposition.
The metaUie per-sulphomolybdates are pnlreralent^ rarely crystalline,
and of a red or reddish yellow colour.
They are all decomposed when strongly heated by themselves. Only
the compounds of tetrasulphide of molybdennm with the sulphides of
aimmonium^ potassium, sodium, and lithium are soluble in water. In.
cold water, indeed, they are but very slightly soluble; but in hot water
they dissolre and form deep red solutions which do not yield any deposit
oh cooling. These solutions, when mixed with a stronger acid, giro off
sulphuretted hydrogen, and yield a precipitate of tetrasulphide of molyb-
denum. (Berselius.)
' If a double ealt of hydrosulphuric acid is supposed to exist in the
aqueous solution, that salt must contain an oxide of molybdenum MoO^
hitherto unknown: «. ^., KS,MoS*H-5HO = KO,HS + MoO*,4HS.
D. SuLPHATB OP MoLTBDovs OxiDB.— -a. Bcuic SulphoU, — 1. Formed
by mixing hydrated molybdous oxide in excess with aqueous sulphurio
acid. — 2. By evaporating a solution of the neutral salt, and decomposing
the residue with water.---d. By adding ammonia to the acid solution of c.
Greyish brown, blistered mass, insoluble in water.
0. Neutral Sulphate. — Formed when the dry hydrated protoxide is
rubbed up in a mortar with an equivalent quantity of sulphuric acid. Pitch-
black, tenacious mass; decomposed by water into an insoluble basic and a
soluble acid salt.
c. Acid /Sk^o^e.-— Prepared by decomposing h with water, or by dis*
solving hydrated molybdous oxide in aqueous sulphuric acid. The nearly
black solution yields on evaporation a olack, tenacious, uncrystaUizable
mass. This when strongly heated gives off sulphurous acid, and is first
converted into sulphate of molybdio oxide, and lastly into a blue com-
pound of sulphuric acid with the blue oxide. The acid salt, mixed with
an additional quantity of sulphuric acid, assumes a purple colour after a
while. (Berselius.)
E. Sulphate of Molybdig Oxide. — Formed by dissolving molybde-
num in hot oil of vitriol, or in a mixture of diluto sulphuric and nitric
acid; or the hydrated molybdic oxide in dilute sulphuric acid; or by heat-
ing bichloride of molybdenum with sulphuric acid. — The anhydrous salt
is black; but when evaporated to dryness at a very high 'temperature, it
assumes a light blue colour. It dissolves in water, yielding a red solu-
tion. (Berzelius.)
. F. SuLPHATB OP Molybdic Acid.— a. Basic Sulphate.'^By boiling
dilute sulphuric acid with an excess of molybdic acid, a turbid, milky
liquid is oDtained, which gelatinises on cooling, and deposits pale yellow
flakes of a basic compound, which is sparingly soluble in water but not in
alcohol; though the tatter colours it green. (Berselius.)
b. Acid Sulphate. — A solution of molyodic acid (not in excess) in
diluto sulphuric acid has a light yellow colour, and dries up to a lemon-
yellow, crystalline mass, which deliquesces in the air, but is only partially
soluble in water. (Berzelius.) — The solution of molybdic acid in sulpbario
acid does not yield crystals on evaporation; but when molybdato of
baryta is decomposed by excess of diluto sulphuric acid, and the clear
solution evaporated over oil of vitriol, crystals are obtained. (Anderson,
Jahre^>er., 22, 161.)
CHLORIDES OF MOLYBDENUM. 63
Calculation, Asdenon.
MoO» 72 .... 34-29 ..., 32-8
3SO». 120 .... 5714 ,... 57-3
2HO 18 .... 8-57 .... 9-9
MoO*«380*-l-2Aq 210 Z lOO'OO Z 100*0
MoiiTBDENUM AHB loDINE,
A. Htdrated Protiodibb of Molybdenuh, or Htdbiodate of
MoLTBDous OxiDB. — lodlne has no action on ignited molybdennm. By
dissolying the hjdrated protoxide in aqueous hydriodic acid, a compound
is obtained, which behaves in all respects like the protochloride of molyb-
denum. (Berzelins.)
B. Htdrated Biniodidb of Molybdenum, or Bihtdriodatb of
MoLYBDio OxTDB. — Hydrated molybdic oxide forms a red solution with
aqueous hydriodic acid. This solution, when spontaneondy eyaporated
in the air, leayes a crystalline residue, which appears red by transmitted
and brown by reflected liffht ; is resolved by heat into yolatile hydrio-
dic acid and fixed molybdio oxide; and is perfectly soluble in water.
(Berzelins.)
MOLYBDBNUM AMD ChLORINE.
A. Protochloride of Molybdenum. — Molybdenum heated nearly
to redness absorl>s the vapour of bichloride of molybdenum passed over it,
and is converted into a hard, compact mass, which appears aark rod when
cold. From this substance, water extracts only a small quantity of proto-
chloride of molybdenum, assuming at the same time a light purple colour;
the remaining red protochloride is insoluble in boiling water and hydro-
ehlorio acid, out is resolved by solution of caustic potash into chloride of
potassium and pure hydrated molybdous oxide, ignited in a tube, the
upper end of whieh is drawn out to a fine point, it sublimes in the form of
a dark brick-red, confusedly crystallized mass, which (with the exception of
a small quantity of bichloride of molybdenum produced by the action of
the air) resembles the unsublimed chloride in its insolubility in water, and
likewise in being decomposed by potash. The fed protochloride of molyb-
denum, on the contrary, when ignited out of contact of air, yields a dark
green sublimate, which dissolves in water in the form of hydrochlorate of
the protoxide, and has precisely the same composition as the red com-
pound. — Protochloride of molylnlennm has therefore two isomeric modifi-
cations like the sesqui-chloride of chromium. (Berzelius.)
Hydrated Protochloride of Molybdenvm, or Hydrochlorate of Molyh-
dotis Oxide. — Formed by saturating aqueous hydrochloric acid with the
hydrated protoxide. The solution, which has a yery dark brown colour,
yields on evaporation a black mass, which is tenacious at first, but after-
wards becomes brittle; redissolves almost entirely in water; but, on
further drying in vacuo, giyes off hydrochloric acid and water, and is con>*
yerted into a black, pulyerulent, insoluble compound of protoxide and
protochloride of molybdenum. (Berzelius.)
B. Bichloride of Molybdenum. — Chlorine eas does not act on molyb-
denuni at ordinary temperatures. When molybdenum is gently heated in
chlorine gas free from atmospheric air, its sur&ce exhibits a transient
ammoHiac,
64 MOLYBDENUM.
glow, and a dork red vapour is formed, which condenses into blackish
grey crystals, having a metallic lustre and strongly resembling crystals of
iodine. Bichloride of molybdenum is very fusible and again forms crys*
tals on solidifying; sublimes at a gentle heat; fumes in the air and then
deliqaesces; dissolves in water with so much evolution of heat that the
liquid boils. When kept in a vessel containing air, it gradually absorbs
oxygen, and yields a white sublimate of molybdate of terchloride of
molybdenum. [Should not Mod* be set free at the same time? 6M0CI*
+ 60 = MoCl%2MoO* + BUoC[\] It combines with eal-
but not with the chlorides of potassium and sodium. (Berzelins.^
HydrcUed Bichloride of Molybdenum, or Bihydrochlorate of Molyhdie
Oxide. — 1. When bichloride of molybdenum deliquesces in the air, it
forms a liquid which is first black, then bluish green, and, as it absorbs
more water, becomes greenish yellow, then rust-coloured, and lastly
yellow. — 2. The hydrated oxide may idso be dissolved at once in hydro-
chloric acid, or metallic molybdenum in hydrochloric acid to which a few
drops of nitric acid are added. The concentrated solution remains tole-
rably permanent in the air, and, on evaporation, leaves black bichloride
of molybdenum; but a dilute solution oxidizes when exposed to the air,
becoming first green, and then blue. (Berzelius.)
A corresponding solution of the blue oxide of molybdenum in hydro^
chloric acid is obtained by treating the metal with chlorine-water — ^by
heating the hydrochlorate of molybdic acid with molybdenum, molybdous
oxide, molybdic oxide, zinc, tin, or alcohol — or by treating it with a small
quantity of hydrosulphuric acid, &c. It has a splendid deep blue colour,
which gradually disappears in the air, from oxidation. When boiled
with potash, it yields a brown precipitate of the hydrated oxide, while
molybdate of potash remains in solution.
C. Hydrated Oxychloride op Molybdenum, or Mono{'i)hydrocfdo^
rale of Molybdic Oxide. — Probably MoO',MoCl* or MoO*,HCl. — Aqueous
hydrochloric acid, or an aqueous solution of bichloride of molybdenum is
completely saturated with the hydrated binoxide. The resulting solution
leaves, by spontaneous evaporation, a dark, amorphous mass, which
readily becomes blue, and is very soluble in water.
D. Molybdate of TERcnLORiDE of Molybdenum. — H. Rose dis-
covered the true nature of this compound, which had previously been
regarded as terchloride of molybdenum. — 1 . When dry chlorine gas is
passed over heated anhydrous molybdic oxide, the compound is ob-
tained in the form of a sublimate. (Berzelius.)— 3MoO* 4- 3C1 = MoCl',
2MoO^ The oxide must be prepared by imperfectly reducing warm
molybdic acid by hydrogen gas; that obtained hy igniting molybdate of
soda with sal-ammoniac (IV.| 51, 4) appears to be mixed with metallic
molybdenum; and accordmgly, when treated with chlorine, yields bichlo-
ride of molybdenum at the same time. (H. Rose.) — 2. A mixture of
molybdic acid, sulphuric acid, and sulphate of potash, is evaporated in a
retort till no more sulphuric acid is evolved; common salt is then added,
and the whole heated to the point of sublimation. But the compound
thus obtained is brown, and, towards the end of the process, becomes
mixed with bichloride of molybdenum. A solution of molybdic acid in
oil of vitriol does not yield any molybdate of chloride of molybdenum by
distillation with common salt, but only hydrochloric acid, followed by
fiulphuric acid containing traces of molybdic acid. (H. Rose.)
FLUORIDES OP MOLYBDENUM. 05
Yellowish white, delicate, crystalline scales, which are infusible, but
volatilize at a temperature below redness, though with less facility than
bichloride of molybdenum. Taste — ^pungent, rough, bitter, and slightly
acid. Easily soluble in water, and likewise soluble in alcohol. (Berzelius.)
Calculation. H. Rose.
3Mo 144-0 .... 48-29 .... 48-22
3C1 106-2 .... 35-61 .... 35*66
60 48-0 .... 16-10 .... 16-12
MoCl8,2MoO».... 298-2 .... 10000 .... 10000
The compound may also be regarded as MoClO* — ^that is to say, as
molybdio acid in which one atom of oxygen is replaced by one atom of
chlorine.
E. Hydrochlobate of MoLrBDio Acid. — Prepared by dissolving
the molybdate of bichloride of molybdenum in water, or molybdic acid in
hydrochloric acid.
Molybdenum and Fluorine.
A. Hydratbd Protofluoride of Molybdenum, or Hydrofluatb
OP MoLYBDous Oxide. — The beautiful purple-red solution of hydrated
molybdous oxide in aqueous hydrofluoric acid dries up, when moderately
heated, to a purple-red yamish, which, at a higher temperature, becomes
brown, and is then no longer completely soluble in water. (Berzelius.)
B. Hydrated Bifluoridb of Molybdenum, or Bihydrofluate of
Molybdic Oxidb. — The solution of hydrated molybdic oxide in aqueous
hydrofluoric acid is red, unless the acid is in yery large excess, in which
case it is almost colourless. After gentle eyaporation, whereby it is soon
tamed blue if the acid is not in excess, it leayes a black, crystalline
residue (of bifluoride of molybdenum?), which redissolyes perfectly in
water, forming a red solution, but loses acid if somewhat more strongly
heated, and, when dissolyed in water, leayes a residue of molybdio oxide.
(Berzelius.)
The blue oxide of molybdenum yields with hydrofluoric acid a deep
bine solution which does not crystallize. (Berzelius.)
C. Hydrated Terfluoride of Molybdenum, or Hydrofluatb of
Molybdic Acid. — Molybdic acid dissolyes readily and abundantly in
aqueous hydrofluoric acid. The colourless solution has a sour and dis-
agreeable metallic taste, and yields, on eyaporation, a yellowish syrup
which exhibits no signs of crystallization; assumes a greenish or bluish
tint when heated, in consequence of minute organic particles &lling into
it; redissolyes but imperfectly in water after being eyaporated to com-
plete dryness; and leayes an insoluble compound of molybdic acid with
a small proportion of hydrofluoric acid, or of molybdic acid with terfluoride
of molybdenum, which, though soluble to a certain extent in pure water,
is precipitated from it by the first- mentioned acid solution.
Several combinations exist of terfluoride of molybdenum with the
more basic metallic fluorides; they are not, howeyer, known in the free
state, but only in combination with salts of molybdic acid : e. ^.,
KO,MoO'+KF,MoF^ (Berzelius.)
vol. ly. P
6S MOLTBDENUM.
Molybdenum and Nitrogen.
A. NiTRATB OF MoLTBDous OxiDS. — Hjdrated mol^bdovs oxide
forms with dilate nitric acid a dark Bolution which rapidly becomes
parple-red. If an excess of the hjdrated oxide is present, a ba$ic salt is
produced. In both componnds, the oxide is rapidly converted into
molybdic acid^ the change being marked by decolorization of the salt.
(Berzelins.)
B. NiTBATE OF MoLTBDic OxiDE. — Formed by digesting dilate nitric
acid with hydrated molybdic oxide, or with excess of molybdenum. The
reddish brown solution can only be evaporated to a certain point; when
further concentrated, it first turns blue, then becomes colourless, eyolves
nitric oxide, and leaves a residue of molybdic acid. (Berzelius.)
C. Nitrate of Moltbdic Acid. — Prepared by dissolving metallic
molybdenum or molybdic acid, not in excess, in nitric acid. The solution
is of a reddish brown colour, has a feebly acid, and subsequently bitter,
metallic, astringent taste^ and gives off nitric acid when evaporated.
(Bucholz.)
Bucholz, by evaporating nitrate of molybdic acid, obtiuned a dingy
reddish yellow residue; by treating it with a small quantity of ammonia,
lie obtained a brownish red powder mixed with white crystals; and by
treating the metal with 8 parts of faming nitric aoid, a pale brownish
red mass was prodnced, with violent effervescence. [Does this consist of
molybdic acid united with a small quantity of nitric acid, or contaminated
with sesquioxide of iron 1]
D. MoLTBDATB OF Amuonia.— a. Moncmolyhdate.*'^!. From the
native Sttlpkide ( WaueMei). Finely divided sulphide of molybdenum ia
roasted in a vessel of clay, porcelain, or platinum, with frequent stirring,
till the whole of the sulphur is expelled. A strong heat is applied at
first, but is afterwards moderated, to prevent the molybdic acid formed
from fusing or volatilizing. The moljrbdio acid which remains is finely
pounded and dissolved by long digestion in ammonia. The solution is
then filtered and evaporated, by which impurities are separated; filtered
again; evaporated to a small bulk; the boiling hot solution mixed with
strong ammonia; and the mixture left to crystallize by spontaneous
evaporation.^2. From native Molybdate of Lead (Gelbbleierg), An inti-
mate mixture of 1 part of the pounded ore with 6 parts of common
potash-liver of sulphur is closely pressed into a hessian crucible, the
cover of which is then luted down, and the whole exposed for an hour
and a half to a strong red heat. The crucible is broken when cold; the
reddish brown mass within exhausted with boiling water; the solution
filtered; and the sulphide of molybdenum (containing copper and iron)
precipitated by dilute sulphuric acid. The sulphide, after being thoroughly
washed, is dried and roasted in a porcelain crucible, till it no louder bums
with a sulphurous flame; after which, as complete roasting would be too
tedious a process, the black residue is dissolved in aqua-regia, filtered,
thoroughly washed, and the green filtrate, together with the blue wash-
ings, evaporated to dryness. The greenish blue residue is then freed
from the hydrochloric and nitric acids by ignition in a porcelain crucible;
the remaining yellowish green mass reduced to powder, and digested with
MOLYBDATE 07 AMMONIA* 67
aqneooB amrnonia; the ligbi-blae solaiion filtered from the brown residae,
oonsifltiiig of seequioxide of iron with a traee of ffypenm; the oopper pre*
dpitated from the filtrate bj a few drops of hydrosnlphate of ammonia;
and the solution filtered and eraporated to a small bnlk. (Wittstein,
Bepert. 7S, 155.) Sranberff d? Stmre prepare the salt hj digesting an
exoees of molybdio acid with strong ammonia in a close vessel, and preci-
pitatinff with alcohol, and drying the precipitate oyer qnick-lime.
MoTjbdate of ammonia crystallises in rectangular prisms nnited in
tofts^ and haring at first a bitterish saline, and snbseqnently, an astrin*
gent metallle taste. (Brandos.) It contains^ according to firandes^ from
75 to 80 per cent, of acid, with from 25 to 20 of ammonia (and water 9).
When ignite4 it 3rields water, nitrogen, and ammonia, leaving a residae of
bro¥ni oxide of molybdenum, or, if air is admitted, of molybdio acid. It
dissolves, according to Brandos, in 2 or 3 parts of water; the solution
gives off ammonia when evaporated.
6. Biiru>lybdoUe. — Prepared by evaporating the aqueous solution of a,
without replacing the ammonia which volatilizes. This salt forms a trans-
lucent, striated, saline mass; or — ^when spontaneously evaporated — ^large
etystals, belonging to the oblique prismatic system, having the base
obliquely inclined to the obtuse lateral edges, with numerous mces, espe-
cially f», a>/, ^; cleava^ distinct parallel to <; transparent, with double
refracting power; havmg a pearly lustre in the direction of the ^faees;
otherwise^ with a vitreous lustre; colour bluish-green, but white when
reduced to powder. The salt has a saline and metallic taste. (Maidinger,
£dnih* J, of Se, 1, 100.) When heated it evolves ammonia, water, and
nitrogen gas, and if air be excluded, leaves brown oxide of mohrbdenum
(Berzelius), which, on admission of air, is converted into molybdic acid«
According to Bucholz, it leaves an ash-grey coloured, and accordixig i6
Wittstein, a greyish-blue oxide. It dissolves sparingly and without
colour in water. IT According to Svanberg & Struve, it is precipitated in
the form of a white powder, by rapidly evaporating a solution of molybdio
acid in ammonia, of which tne liquid should smell permanently. From
an ordinary solution of this kind, a compound of bimolybdate and termo-
lybdate of ammonia with S atoms of water crystallizes [on cooling 9], in
colourless and transparent six-sided prisms. Different salts are also
obtained by the action of nitric acid on solutions of molybdio acid in
ammonia; but they have not been further examined. IT
c. Hyper add molyhdaU 9 — According to Brandos, this compound is
precipitated from a solution of a or 6, on the addition of sulphuric add, in
the form of a white powder, from which the sulphuric acid with the aid of
heat, removes every trace of ammonia. Acetic acid in excess, likewise
precipitates dazzling white crystals, which disengage ammonia on the
addition of potash, and when ignited, first become greyish blue, and then
leave 98*9 per cent of pure molybdic acid. (Wittstein.)
If to a strong solution of molybdate of ammonia a very small quan*
tity of concentrated aqueous phosphoric acid is first added, and then a
considerable quantity of hydrochloric, sulphuric, or nitric acid-^or one
of these acids first, and phosphoric add afterwards--o lemon-yellow, ctrs*
falline powder is precipitated, and with greater rapidity in proportion
as the solution is more concentrated. This precipitate, besides molybdic
add, contains a small portion of ammonia, but no phosphoric acid, or at
most a mere trace. With potash it evolves ammonia, and forms a colour-
less liquid, from which, even after long boiling, it is again precipitated
by hydrofluoric acid ; but if the solution in potash is evi^rated to diy<*
F 2
68 MOLTBDEKUM.
ness, and the residue dissolved in water, hydroflnoric acid merely produces
a yellow colour; but hydrofluoric acid and sal-ammoniac together throw
down a yellow powder. The yellow powder yields with hot oil of vitriol,
a colourless solution which is not precipitated by water. It does not
dissolve perceptibly in cold water, or in dilute sulphuric, hydrochloric, or
nitric acid ; and but very sparingly in boiling water, to which it does not
impart any colour. (Gmelin.) IT According to Svanberg & Struve, the
yellow powder consists of NH*0,5M0'-f HO, besides a small quantity
of phosphoric acid. By boiling with potash, a colourless solution is
obtained, which yields with acids a yellow crystalline precipitate, in which
the NH*0 is replaced by KO. A solution of the yellow ammoniacal salt
in ammonia gives a white precipitate with chloride of barium^ which
turns yellow on the addition of an acid. IT
E. Carbonate op Molybdous Oxide and Ammonia. — Hydrated
molybdous oxide does not dissolve in pure ammonia or its carbonate; but
when molybdous salts are supersaturated with carbonate of ammonia,
the precipitate first formed redissolves, producing a dark brown solution,
which, on boiling, again deposits the molybdous oxide as a basic salt.
(Berzelius.)
P. Carbonate op Moltbdic Oxide and Ammonia. — Hydrated
molybdic oxide is soluble in aqueous solution of carbonate of ammonia,
and separates again completely when the liquid is boiled. (Berzelius.)
G. Phosphate op Molybdous Oxide and Ammonia. — Molybdous
phosphate dissolves in ammonia, forming a blackish brown solution.
(Berzelius.)
H. Sulphomoltbdatb op Ammonium. — NH*S,MoS^ — 1. Prepared
by saturating monomolybdate of ammonia with hydrosulphuric acid and
evaporating to a small bulk. — 2, By dissolving molybdic acid in bihydro-
sulphate of ammonia, and expelling the liberated ammonia by evaporation.
3. By dissolving recently precipitated tersulphide of molybdenum in
hydrosulphate of ammonia. The solution obtained by either of these
methods is mixed in a moderately concentrated state with alcohol. The
compound separates in the form of a cinnabar-coloured powder, -—or, if the
mixture is made with warm solutions, crystallizes on cooling in cinnabar-
coloured scales. It becomes dark brown on exposure to the air. Dis-
solves with facility in water, but very sparingly in alcohol. Its aqueous
solution, when spontaneously evaporated, evolves hydrosulphate of ammo-
nia, and deposits round the sides of the vessel a few crystals which,
reflect light of a green colour; but the greater part dries up to a
blackish-grey, brilliant, uncrystallizable compound of hydrosulphate of
ammonia with excess of tersulphide of molybdenum, which dissolves
rather freely in water, but is very sparingly soluble in alcohol. (Berzelius.)
I. Per-sulphomoltbdate op Ammonium.— NH*S,MoS*. — Tetrasul-
phide of molybdenum digested while still moist with hydrosulphate of
ammonia containing excess of ammonia, is converted into a yellow powder.
The presence of free ammonia renders the now compound less soluble in
the liquid. The powder when dried in the air becomes dark red, pro-
bably from disengagement of hydrosulphate of ammonia. It dissolves
slightly in cold water, forming a yellow solution, and more abundantly in
hot water, but is totally insoluble in solution of ammonia. (Berzelius.)
MOLYBDENUM AND POTASSIUM. 69
K. Hydrochlobate op Molybdous Oxide and Ammonia. — Dark-
coloured, crystallizable double salt. (Berzelius.)
L. Hydrochloratb op Molybdig Oxide and Ammonia. — a. An
aqueous mixture of bichloride of molybdenum and sal-ammoniac yields by
spontaneous evaporation, small, brown crystals wbicb are permanent in
the air. — b. If bichloride of molybdenum is treated with ammonia till the
precipitate first formed just redissolves, and the solution then left to eva-
porate spontaneously, a black crystalline mass remains which dissolves
in water, forming a red solution. (Berzelius.)
M. Monofluoride op Molybdenum and Ammonium, and Hydro-
FLUATB op Molybdous Oxide and AMUOviA.-^AmmoniO'/tioride of
Molybdenum. — Precisely analogous to the potassium compound. (Berzelius.)
N. Bipluoride op Molybdenum and Ammonium, and Hydro-
fluate op Molybdic Oxide and Ammonia. — Ammonio-perfiuoride of
Molybdenum, — Reddish-yellow mass, more soluble in water than the
corresponding potassium compound, (Berzelius.)
Molybdenum and Potassium.
Neither molybdous nor molybdic oxide dissolves in solution of potash.
(Berzelius.)
A. Molybdate op Potash.— (J. Monomolybdate, — Obtained similarly
to the molybdate of ammonia, — or, in an impure state, by detonating a
mixture of one part of native sulphide of molybdenum ( Wctsserblei) with
3 parts of nitre. Crystallizes in permanent, brilliant needles, which have
a rough metallic taste, are fusible, and dissolve readily in water. (Bucholz.)
IT According to Svanberg & Struve, (J. pr. Chem, 44, 257), this salt is
best prepared by adding moist termolybdate of potash to a solution
of caustic potash in alcohol of 95 per cent. TLe salt separates in the
form of an oily mass at the bottom of the vessel; this, after being washed
with alcohol, is left to crystallize under a bell-jar, beside caustic lime and
oil of vitriol. Crystallizes in four-sided prisms, with two truncation-
surfaces resting on the narrower lateral faces. Readily soluble in water.
When heated it loses water, and is converted into a white powder, which
fuses at a high temperature, and on cooling solidifies to a crystalline niass.
Its formula is KO,MO»+iHO.
Anhydnmt, Svanberg & Strnve*
KG 47-20 .... 40-70 .... 40*71
MoO» 70-06 .... 69-80 .... 59-29
117-26 Z, 100-00 Z. 100-00
In this calculation the atomic weight of MO is taken as 46*06. 1
b. Bimolybdate. — This salt is obtained as a white precipitate, by
decomposing a concentrated solution of the salt a with sulphuric, hydro-
chloric, or nitric acid, or chlorine gas. It crystallizes in brilliant, oblique,
four-sided laminae ; fuses more readily than molybdic acid, attacking the
earthen crucible rapidly, and assuming a fine-yeUow colour when cold. It
dissolves sparingly in cold water^ but in 3 or 4 parts of boiling wat^r. The
70 IfOLTBDENUM.
eolation is precipitated reddish-brown by ferrocyanide of potaBsinm.
(Bucbolz.) Acids tbrow down the salt from a cold solution. The sola-*
tion in hot water deposits, on cooling, white bulkj flakes of a still more
acid salt which does not redissolve in boiling water. (Berzelias.^
IT Syanberg & Strnve did not succeed in obtaining this salt. When
strong nitric or hydrochloric acid is cautiouriy added to a solution of
molybdic add in carbonate of potash, till the resulting precipitate no
longer entirely disappears, a compound salt crystallizes out, consisting
dther of 3(K0, 2MoO») -f KO, 3MoO* -«- 6H0, or 3(K0, MoO>) + 5(K0,
3M0O') + 12H0. It is resolved by water into termolybdate and mono-
molybdate of potash, which dissolyes.
e. Termolybdate of Fota8h.—KO,SUoO^ +9110.— Th^ most readily
prepared of all the compounds which molybdic acid forms with potash.
If a solution of molybdic acid in carbonate of potash be treated with
hydrochloric acid till it becomes turbid, and then set aside, a mixture of
monomolybdate and termolybdate of potash separates after a while in six-
sided prisms, (vid. sup.) On treating these crystals with water, they
are resolved into difficultly soluble termolybdate and easily soluble mono-
molybdate of potash. The termolybdate forms a bulky white precipi-
tate, which contracts considerably on drying, and consists of microscopic
needles. It is soluble in boilinfi^ water, from which it separates but
slowly. It may also be obtained by adding nitric acid in excess to a
saturated solution of molybdic acid in carbonate of potash^ washing the
precipitate with cold water, then dissolving in boiling water, and crystalliz-
mg. The boiling water often leaves a residue consisting sometimes of
4etnunolybdate, sometimes of pentamolybdate of potash. (Svanberg &
Struve.)
d, Tetramclyhdaie and Pentamolyhdate of Potash, — 1. The yellow
powder obtained by precipitating molybdate of ammonia with phosphoric
acid, &c. (p. 67) is heated with solution of potash till the ammonia is
expelled. The resulting colourless solution is then mixed with nitric acid,
whereby a yellow crystalline precipitate is obtained, the formula of which
is KO, 5MoO' + 2HO.-*2. By adding an excess of nitric acid to a solution
of molybdic acid in carbonate of potash, sometimes tetramolybdata,
sometimes pentamolybdate of potash is precipitated, {yid, sup,) Both
salts are white, anhydrous, insoluble in water, easily fusible, and solidify
in a ciystalline mass. (Svanberg &c Struve.) IT
B. Carbonatb of Moltbdio Oxide and Potash. — The recently pre-
cipitai;ed hydrate of molybdic oxide dissolves but sparingly in an aqueous
solution of carbonate of potash, imparting to it a yellow colour; the
anhjydrons oxide is totuUy insoluble. By supersaturating a molybdic salt
with carbonate of potash, perfect solution is effeoted, because an excess of
carbonic acid is then present in the liquid. On boiling the solution, a large
quantity of the hydrated oxide is tnrown down, and carbonic acid is
evolved; a portion, however, still remains dissolved. When exposed to
the air, the solution becomes colourless in a few days, from formation of
molybdate of potash. (Berzelins.)
C. SuLPHOMOLYBDATE OP PoTASSiUM. — «. Normal Salt. — KS,MoS'.
•—1 . A finely divided mixture of equal weights of carbonate of potash
and sulphur, with a small proportion of charcoal and a large excess of
native sulphide of molybdenum, is put into a hessian crucible and coveted
with powdered charcoal. The whole is then exposed to a heat below
MOLYBDENUM AND POTASSIUM. 71
redness till pentasalphide of potassiam is formed — after which it is strongly
if^ited for three hours, or as long as sulphurous acid contiuaes to be
erolved. In this process, one atom of sulphur passes from the pentasal-
phide of potassium to the bisulphide of molybdenumi and the resulting
tersulphide of molybdenum unites with protosulphide of potassium formed
by the expulsion of 3 atoms of sulphur. The black, porous, unfused
mass is dissolved in water, whereby it becomes heated; the dark red
solution, separated by filtration from the unaltered portions of ore, is
evaporated m a cylindrical glass vessel at a temperature of 40°; and the
crystals obtained are dried between folds of bibulous paper. — 2. Mono-
molybdate of potash is saturated with hydrosulphuric acid and evaporated
to the crystallizing point. — A small Quantity of this sulphur-salt is also
formed by digesting the native sulpnide of molybdenum and potassuun
with an aqueous solution of pentasulphide of potassium. (Berzelius.)
The salt crystallizes in four and eight>siaed prisms, sometimes with
dihedral summits, in which case it resembles the octohedron; or sometimes
(if crystallized from a hot solution) perpendicularly truncated. By reflected
light it exhibits a beautiful green, metallic colour, like the wing-<;a8es of
many kinds of beetles; by transmitted light it is ruby-red. Fracture
uneven and conchoidal, exhibiting a green colour. Its powder is dark-
red, but becomes green and lustrous by pressure.
Crystallized. Or:
K 39-2 ..,. 25-92 KS 55-2 .... ZB'hi
Mo 48-0 .... 31-75 MoS» 960 .... 63-49
48 64-0 .... 42-33
KS,MoS» 151-2 .... 100-00 151-2 .... lOO'OO
The crystals, when heated in hydrogen gas (or, in short, out of contact
of air) become grey ; and though about a third of the compound remains
iindecomposed even at a white heat, the rest appears to be converted
into a mixture of bisulphide of molybdenum and bisulphide of potassium,
the latter of which, together with the original unalteied sulphur-salt,
may be removed by water: KS,MoS'=KS*-|-MoS«. The crystals, when
decomposed by hydrochloric acid, yield from 49*2 to 49*5 per cent, of
chloride of potassium. They dissolve in water, forming a beautiful
yellowish red solution, from which alcohol precipitates nearly the whole
of the salt, at first in the form of a cinnabar-red powder, afterwards
on standing, in cinnabar-red scales, which, when dried, assume a metallio-
green colour. — The supernatant alcoholic solution, which is of a Gjoe red
colour, yields similar crystals on evaporation. (Berzelius.)
b. With 2 aiwM of gulphur-acid. ^From an aqueous solution of tho
salt a, a portion only of the potassium comjpound is separated by an acid
(the best acid for this purpose is acetic acid added till the liquid reddens
litmus, because it does not, like the stronger acids, decompose the com-
pound b when added in excess), and the liquid, which is still clear, though
of a darker colour, is left to evaporate spontaneously. The solution
first assumes a gelatinous consistence, and then leaves a blackish -grev
shining mass; or if acetic acid is previously used, the acetate of potash
which is formed precipitates the new compound from the concentrated
solution as a brownish yellow powder, which on drying becomes greyish
black with metallic lustre; dissolves slowly in cold water, with a pale
yellow colour, but rapidly in boiling water, prodiiciag a dark yellow
solution. (Berzelius.)
72 MOLYBDENUM*
D. Per-sulpuomoltbdate op Potassium.— KS, MoS^ — 1. Prepared
bj the method described (p. 61), the crystals formed being purified
from bisulphide of molybdenum either by elutriation, or by solution in
water, filtration, and evaporation. — 2. A dilute aqueous solution of the
compound of protosulphide of potassium with excess of tersulphide of
molybdenum (C. b) is heated to a temperature of 60° or 80°; whereupon
the liquid^ under the influence of the air, becomes turbid and deposits the
peisulphomolybdate of potassium.—-^. Tetrasulphide of molybdenum is
digested, while still moist, with an aqueous solution of bihydrosulphate
of potash. The portion which first dissolves is again deposited, and after
a short time the liquid loses its colour, and the mass is converted into a
reddish-yellow powder. — When tersulphide of molybdenum is mixed with
the tetrasulphide, the former remains dissolved, imparting a reddish-
yellow colour to the liquid; by this means, the two sulphides of molyb-
denum may be easily separated. (Berzelius.)
When prepared by the first method, the compound has the form of
small, rectangular, ruby-red, transparent scales, transversely striated on the
longer £B«es. The second method yields it in the form of a pulverulent
precipitate, which unites on the niter into a reddish-yellow mass, con-
sisting of small, silky, crystalline particles. When obtained by evapo-
rating the aqueous solution, it forms a transparent red mass of the con-
sistence of an extract. The crystals, when gently ignited, decrepitate
slightly, giving off water and minute quantities of sulphur and hydrosul-
phuric acid, — and are resolved into a grey shining mixture of bisulphide
of molybdenum in crystalline scales and tersulphide of potassium, the
latter of which may be removed by water. KS,MoS*=KS'+MoS*. This
compound dissolves but venr sparingly in cold water, forming a pale
yellow solution, and is insoluble in a cold solution of potsish; boiling water
dissolves it with a red colour, and does not deposit it again on cooling.
Hydrochloric acid added to the solution precipitates tetrasulphide of
molybdenum. (Berzelius.)
E. Sulphate op Molybdic Oxide and Potash.— Molybdic oxide
dissolyes slowly in bisulphate of potash, when fused with it in a close
vessel. The compound is readily soluble in water, forming a yellow
solution. (Berzelius.)
P. Protochloride op Molybdenum and Potassium, and Hydro-
CHLORATB OP MoLYBDous OxiDE AND PoTASH. — Formed whon the black
liquid obtained by the action of amalgam of potassium on a solution of
protochloride of molybdenum (p. 49) is evaporated to the crystallizing
point. — Black, efflorescent salt, which, when redissolved in water, leaves
a black powder, probably a basic salt. (Berzelius.)
G. Protopluoride op Molybdenum and Potassium, and Hydro-
pluate op Molybdous Oxide and Potash. — Molyhdo-fiuoride of Potas-
zium, — Precipitated in pale rose-coloured flakes on mixing the aqueous
solutions of protofluoride of molybdenum and h^drofluate of potash. These
flakes dissolve in water containing hydrochloric acid, and separate again
on evaporation or simple cooling, in the form of a dark rose-coloured
powder, which becomes paler when dried. (Berzelius.)
H. Bifluoridb op Molybdenum and Potassium, and Hydropluatb
OP Molybdic Oxide and Potash. — J^ermolybdo-fiuoride of Potassium.-^
MOLYBDIC ACID AND SODA. 73
An aqaeous solntion of hydroflaate of potash precipitates from a solution
of hydroflaate of molybdic oxide a reddish-brown powder^ sparingly
soluble in water. (Berzelius.)
I. SULPHOMOLYBDATE OP PoTASSIUM WITH NiTBE.— -When equal
weights of the two salts are dissolved in water and the solution left to
evaporate spontaneously^ green crystals are obtained, possessing the
metallic ]ustre> and closely resembling those of sulpho-molybdate of
potaseium : they explode like gunpowder when heated. (Berzelius.)
HOLYBDENUM AND BODIUH.
A. MoLYBDATE OF SoDA.-— a. MonomolyhdoU. — ^Prepared in a similar
manner to molybdate of potash. — Forms large efflorescent crystals, having
a rough taste, fusing readily, but not volatile. — ^According to Brandes,
70*87 parts of acid are required to neutralize 2963 parts of soda. — The
salt is not decomposed at a red heat. Acids precipitate from it an acid
salt. It U very soluble in water.
IT By fusing 5*491 parts of molybdic acid with 4*074 parts of carbo^
nate of sod% a mixture is obtained which solidifies in a crystalline mass
on cooling; it is very soluble in water; crystallizes from an aqueous solu*
tion by evaporation in small rhombohedrons; and contains 30*36 per cent,
of soda: NaO,MoO»+2HO.
h, Bimolyhdate of Sodcu — NaO,2MoO*+HO. — Prepared by fusing
2*4325 parts of molybdic acid with 0*919 parts of carbonate of soda.
Difficultly soluble in cold water after ignition. Dissolves in hot water
aiter a considerable time. Contidns 18*20 per cent, of soda.
c. TermolybdaU of Soda,— NM, 3MoO'+7HO.— Nitric acid is added
io a saturated solution of molybdic acid in carbonate of soda till the liquid
acquires an acid reaction. After some time, a voluminous precipitate of
the termolybdate is deposited. More soluble in water than the bimolyhdate.
Contains 13*24 per cent, of soda. Molybdic acid is not precipitated from
solutions of its soda-salts by excess of nitric add, except with the aid of
heat. (Svanberg & Struve.) IT
Molybdic acid heated with carbonate of soda on platinum before thd
blowpipe, effervesces, and forms a bead which is clear while hot, but be-
comes milk-white on cooling. In the inner flame the bead becomes brown,
and is transparent while hot, but turbid or opaque when cold; and if it
contains a rather large proportion of molybdic acid, likewise becomes
charged in the inner flame with brown oxide and reduced metal. On
charcoal, the first portions are absorbed, and reduced to the metallic
state within the substance of the charcoal : if fresh molybdic acid is then
laid on the charcoal, together with a small quantity of carbonate of soda,
and exposed to a powerful reducing flame, a bead is obtained, consisting
of metallic molybdenum and molybdate of soda, separable by means of
water. (Berzelius.)
B. Carbonate op Molybdtc Oxide and Soda.— Prepared like the
corresponding potash compound. (Berzelius.)
C. Borax on platinum in the outer blowpipe-flame forms with molyb-
dic acid a transparent and colourless glass. This glass, when exposed to
the inner flame on charcoal, becomes dirty brown; and if \i contains a rather
I
f4 MOLYBDENUM.
laige qaanUtj of moljrbdic acid, becomes torbid^ uad deposita numerous
brown flakes of moljl>aic oxide. (Berzelius.)
D. Microcosmic salt forms with molybdic acid on platinum in tbe outer
blowpipe-flame a transparent glsMSs, which is green while hot, and colour-
less when cold. It maj also be obtained colourless while hot by prolonged
exposure in the enter flame. In the inner flame or on charcoal it appears
black or dark blue and opaque while hot, and on cooling assumes a splen-
did green e<4oiur and becomes transparent. (Berzelius.)
E. SuLPHOMOLYBDATB OP SoDiUH. — ^NaS, MS*. — An aqueous solu-
tion of monomoljbdate of soda is saturated with h jdrosulphuric acid, and
eyaporated to a small bulk. The whole becomes conyerted into a mass of
small, granular, dark red crystals. Sometimes also slender needles are
obtained as the liquid cools; these, after being dried on bibulous paper,
appear green by reflected light. The compound is decomposed by igni-
tion, like the potassium salt, but much more completely. By repeated
solution in water and recrystaliization, it acquires a light red colour
and radiated structure, in consequence of the production of moiybdate of
soda. It is not precipitated from an aqueous solution by alcohol^ or at
most to a very slight extent. (Berselius.)
6. With two atofiu f of StupkurHteid. — ^Prepared in a similar manner
to the potassium compound, which it exactly resembles. Dissolves slowly
in water. (Berzelius.)
F. Per-bvlphomoltbdatb of SoDnTM.^-Prepared similarly to the
corresponding potassium compound, with which it agrees in phyisical and
chemical properties; it cannot however be crvstallized, but forms a
reddish yellow powder sparingly soluble in cold water, but readily disr
solving by boiling water. (Berzelius.)
G. Flttoride of Molybdenum and Sodium, and Htdrofluate op
MoLYBDOUS Oxide and Soda.— More soluble than the potassium salt;
it is deposited on evaporation as a rose-coloured, ctystalline powder,
(Berzelius.)
H. BiFLUORIDB OF MOLYBDENUM AND SoDIUM, and HyDROFLUATE
OF MoLYBDio Oxide and Soda. — Behaves in a similar manner to the
corresponding ammoniacal salt. (Berzelius.)
Molybdenum and Lithium.
A. SuLPHOMOLYBDATB OF LiTHiuM. — The aqueous solution yields
on evaporation a brown syrupy liquid, which slowly dries up to a dark
red, amorphous mass. When heated, this substance is completely resolved,
into bisulphide of molybdenum and bisulphide of lithium; the latter of
which may be removed by water. The compound does not deliquesce
in the air, but dissolves very easily in water. It likewise enters into
combination with excess of tersulphide of molybdenum. (Berzelius.)
B. Per-sulphomolybdate OF Lithium.— Pale yellow, somewhat
crystalline powder, which is slightly soluble in cold water, and dissolves
MOLYBDATE OF BARYTA. 76
readily in boilifig water, forming a red solation. The latter solution
depoeite nothing on cooling, but when eyaporated leares a red residue of
ib» ooDsistenoe of extract. (BeraBelias.)
Molybdenum and Barium.
A. MoLYBDATE OP Baryta. — a, Dimolybdote. — ^Precipitated from a
eolation of b in dilute nitric acid, by supersaturating the liquid with
ammonia. Forms a white powder, which also remains white after igni-
tion; soluble in dilute hydrochloric or nitric acid.
For the preparation of this salt, the pigs of iron obtained from the
Mansfeld copper furnaces may be used. For this purpose they are reduced
to powder; fused with carbonate of soda; the fused mass exhausted with
water; the filtrate supersaturated with nitric acid, warmed to expel car-
bonic acid, and mixed with nitrate of baryta; the liquid then filtered from
sulphate of baryta; and the dimolybdate of baryta precipitated by ammo-
nia and washed with cold water. (Heine, J, pr. Chem. 9, 204.) [Is not
vanadic acid concerned in this action 1] (Syanberg & Struye doubt the
existence of this salt.)
JJter iffnition, Heine.
2BaO 153-2 .... 68-03 .... 6804
MoO» 720 .... 31-97 .... 31-96
2BaO,MoO*.... 225*2 Z. 10000 10000
DrM ai 80^ Heine.
2BaO 153-2 .... 65*41 .... 64-72
MoO* 720 .... 30-75 .... 30-39
HO 9-0 .... 3-84 .... 4-89
+ Aq 234-2 Z 100*00 Z 10000
6. Jfono9noZ;^5c2a<«.— Molybdate of potash throws down from a solution
of acetate of barjrtaa white fioooulent precipitate, which rapidly condenses
to a crystalline powder. This compound turns blue on ignition. (Ber-
selios.) It disBofyes in hydrochloric or nitric acid, which then by spon-
taneoos eyaporation depoats the salt in the form of a crystalline crust.
It is insoluble in water. According to Brandos, it contains 51-55 per
cent, of baryta to 48*45 of molybdic acid.
IT According to Syanberg & Struye, molybdic acid forms a great
number of salts with baryta.
The normal salt is prepared by precipitating a solution of molybdic
acid in excess of ammonia by chloride of iMkrium. Fine, crystalline pow-
der, sparingly soluble in waAer; infusible. Contains 52*17 per cent, of
baryta. If the yellow ammoniacal compound (p. 67) be dissolyed in
ammonia^ and chloride of bariom added, a white precipitate is obtained,
which behayes like the monomolybdate, excepting that it assumes a
yellow colour when treated with acids. It contains 50*07 per cent, of
baryta^ 1*83 of ammonia, 46-77 of molybdic acid, and 1*09 of phosphoric
acid; hence it appears to be monomolybdate of baryta with small quan-
tities of ammonia and phosphoric acid.
c. Five-halves MolyhdaU of -Baryto. — 2BaO, 5MoO' + 6H0, or
(BaO, 2MoO^) + (BaO, 3MoO')-)-6HO.,-~Obtained from the corresponding
ammoniacal salt m the form of a white flocculent precipitate. Uncrystal-
lizable; rather. s<4able ia water; fusible j the fused salt solidifies in a
cr^rstalline form.
76 MOLYBDENUM.
d. TermolyhdcUe of Baryta, — BaO,3MoO'+HO. — A corresponding
alkaline salt is precipitated by chloride of barium. White, flocculent
precipitate, soluble to a certain extent in water. When dry, it forms a
yellowish, white, homy mass. Fuses at a red heat, and solidifies on cool-
ing to a crystalline mass. Contains 26*66 per cent of baryta.
t, Nonomolybdaie of Baryta, — BaO, 9MoO'+4HO. — Prepared from
the normal salt by treating it with dilute nitric acid. Crystallizes in
email, six-sided prisms; insoluble in water; infusible. %
B. SuLPHOHOLYBDATE OF Barium. — Sulphide of barium is boiled
with water and excess of tersulphide of molybdenum — the solution filtered
boiling hot into a hot slass yessel — ^and left to cool. After a short time,
numerous brownish red, brilliant crystals appear, which, when laid on
paper, crumble to a shining, reddish-yellow powder. When gently heated
they give off water and become red; they are not decomposed by cold
concentrated hydrochloric acid, but somewhat readily by dilute hydro-
chloric acid, sulphuretted hydrogen being eyolved and tersulphide of
molybdenum precipitated. The crystals consist ef BaS,3MoS'. — The
mother-liquid poured off from the salt and again eyaporated, yields a
further quantity of crystals, and then dries up to a dark red, translucent,
uncrystallizable mass, composed of BaS,MoS^ (Berzelius.)
C. Per-sulphomolybdate of Barium. — The corresponding potassium
compound produces with chloride of barium a yellowish-red precipitate,
which is not decomposed by dilute hydrochloric acid, and is insoluble in
water, which, howeyer, makes it denser and giyes it a cinnabar colour.
(Berzelius.)
Molybdenum and Strontium.
A. Molybdatb of STRONTiA.«^Insoluble in water.
B. Sulphomolybdate of Strontium. — The compounds, SrS,MoS'
and SrS, SMoS^ possess similar properties to the corresponding compounds
of barium. (Berzelius.)
C. Per-sulphomolybdatb op Strontium.— -Prepared like the barium
compound, (Berzelius.)
Molybdenum and Calcium.
A. Molybdate of Lime. — Molybdate of potash precipitates from a
solution of chloride of calcium a white powder, insoluble in water but
soluble in hydrochloric acid.
B. Sulphomolybdate of Calcium. — By proceeding as in the pre-
paration of the barium compound aboye described, smau, delicate, bril*
liant, transparent, cinnabar-coloured needles, a, are obtained, which are
permanent in the air eyen at 100°, and are blackened by hydrochloric
acid from separation of tersulphide of molybdenum; they consist of
CaS,3MoS*. — b. The mother-liquid leayes on evaporation^ a dark Ted,
translucent yarnish = CaS,MoS'. (Berzelius.)
MOLYBDATB OF CERIUM. 77
C. F£R-snLPHOi£OLYBDATE OP Calcium. — ^Whcii the Corresponding
potassium salt is mixed in solution with chloride of calcium and alcohol
addedy tbe liquid hecomes slightly turhid, and in the course of twelve
hours deposits a scarlet powder sparingly soluhle in water. (Berzelius.)
Molybdenum and Magnesium.
A. MoLYBDATE OP Magnesia. — Prepared hy boiling ma^esia with
molybdic acid and water. Crystallizes in small, white, tonr-sided prisms
united together in cauliflower-like masses, which are permanent in the
air, and h&ve at first a bitterish, afterwards an astringent metallic taste.
The crystals when ignited, give off their water of crystallization (amount-
ing, according to Berzelius, to 28 per cent., or 4 atoms), and are converted
into a yellow mass; they dissolye in 12 or 15 parts of cold water. TBrandes.)
The anhydrous salt contains 22*15 per cent, of earth to 77*83 ot acid; the
crystallized salt 15*5 of earth, 54*5 of acid, and 30*0 of water. (Brandos.)
B. SuLPHOMOLYBDATE OF MAGNESIUM. — Formed by boilinff tersul-
phide of molybdenum with an aqueous solution of bihydrosulphate of
magnesia. The filtrate as it cools deposits a dark-brown, pulyerulent
compound of sulphide of magnesium with more than one atom of tersul-
phide of molybdenum, while the mother-liquid dries up to a dark-red
Tarnish, which contains the two metallic snlphides in atomic proportions.
(Berzelius.)
C. Pbr-sulphomoltbdatb of Magnesium. -—Prepared by double
decomposition. Forms a red precipitate, insoluble in water. (Berzelius.)
Molybdenum anp Cerium.
A. MoLTBDATE OP Cerous Oxide. — Precipitated from a solution of
a cerous salt by an alkaline molybdate, in white flakes which are insoluble
in water but dissolye in seyeral of the acids. (Hisinger & Berzelius.)
B. Cerous Sulphomoltbdate. — CeS, MoS'. — The corresponding
potassium compound dissolyed in water, produces with a salt of cerous
oxide, a blackish-grey precipitate, which, after drying, forms a dark
brown powder. (Berzelius.)
C. Ceric Sulphomoltbdate. — Ce*S',3MoS'. — ^Prepared by precipi-
tating a salt of the sesqnioxide of cerium as above. Only a portion of
the compound is thrown down as a brown precipitate ; the greater part
remains dissolved, and produces a dark reddish-yellow solution. From
this solution, ammonia throws down a more basic compound in tbe form
of a brown viscid mass, which stops up the pores of the filter. (Berzelius.)
D. Cerous Per-sulphomolybdate, and C£Ric Per-sulphomolyb-
BATE. — Prepared by precipitating cerous and ceric salts by a solution of
tetrasulphide of molybdenum. Red precipitate. (Berzelius.)
78 MOLTBDENUIff.
HOLTBDSNXTM AND YtTRIVM.
A. MoLTBDATB OF Yttria. — ^Moljbdaie of ammonia gives with salts
of yttria a white curdy precipitate which dries np to a white powder.
The salt is insoluble in water^ but dissolres readily in nitric acid.
(Berlin.)
B. SuifPHOMOLTBDATH OF Yttkium.— ^D aijueous Solution of sulpho-
molybdate of potassium does not precipitate acetate of yttria. The liquid
becomes colourless in the course of twelre houn^ and deposits tersulphide
of molybdenum. (Berxelius.)
G. Per-sulphomoltbdatb of YxTBiirM. — Formed by precipitatins^
a salt of yttria by an aqueous solution of the potassium oompound. Bed
powder. (Berselius.)
MOLTBDENUM AND GlUCINUM.
A. SuLPHOMOLTBDATB OP GiiUciNUM. — Prepared like the yttrium
compound. The mixture^ howeyery deposits the tersulphide of molyb^
denum more slowly, and consequently retains its red colour for a longer
time. (Berzelius.)
B. Per-sulphomoltbdate of Olttcinum. — Prepared by the same
method as the yttrium compound.
H0X.TBDB1«1TM AND AliUMINVM.
The aqueous solution of sulphomolybdate of potassium mixed with
salts of alumina gives off hydrosulphuric acid, and forms an immediate
precipitate, consisting of a mixture of tersulphide of molybdenum and
Jiydrate of alumina. When a solution of per-sulphomolybdate of potas-
sium is mixed with a salt of alumina, a red liquid is produced which
appears to be clear, but when filtered leares the colouring matter on the
filter. (Berzelius.)
MOLTBDBNVM AND ThORXNITV.
MoLTBDATB OP THORiNA.-*-«Alkaline monomolybdates and Inmolyb^
dates produce in salts of thorina a white flocculent precipitate, (Benselius.)
HoLTBDENtTM AND SlLICIlTtf.
A. Silicate op Moltbpous Oxide. — Precipitated on mixing the
double fluoride of silicium and molybdenum with ammonia in dark brown
flakes, from which the ammoniacaJ solution gradually remores the pro-
toxide, leaving pure silica below. (Berzelius.)
B. Silicate of Moltbdic Oxide. — ^Prepared by decomposing the
hydrofluate of silica and molybdic oxide with ammonia. Its behaviour
is similar to that of the preceding compound. (Berzelius.)
MOLYBDENUM AKD MOLYBDENUM. 7^
C. Htdrofluatb op Silica and Moltbdoub OxmB.^-^Iiolybdch
^voride of SUieium. — ^A solotion of the bydrated protoxide in excess of
hjdrofluosilicie add, does not dry np in the air at ordinary temperatnres;
bat when gently heated it parta with its excess of acid, and yields a black
nentral compound, which redissolres in the aqueons acid. (Berzelins.)
D. Htdrofluatb ot Silica and Molybdic Oxidb. — Bimolyhda*
^uoride of SUicium, — The acid aqneons solution, when spontaneously
eraporated, acquires a bluish tinge, and yields a black unciystallizable
mass, from which water dissolves out the blue salt, learinff the neutral
eompound in the form of a jet-black powder. This powder is reeolred by
the prolonged action of the water into an acid salt which dissolves, and
an insoluble basic compound. By ammonia, which withdraws the hydro**
fluoric acid, it is converted into silicate of molybdic oxide. In acidulated
water it dissolves without decomposition. (Berzelius.)
E. Hydrofluatb of Molybdic Acid and SihiCA.^^PermolybdO'Jliu}'
ride of SUicium, — ^With molybdic acid, hydrofluosilicic acid forms a
yellowish solution. This solution when evaporated, leaves a lemon*
yellow, opaque substance, which redissolves for the most part in water,
forming a yellow solution, a small quantity of a hcuic compound being
left behind. (Berzelius.)
Molybdbnum and Titanium.
Sulphomolybdate of potassium in solution, behaves with salts of
titanium in the same manner as with salts of aluminum. (Berzelius.)
Molybdenum and Tungsten.
A. TuNOSTATE OF MoLYBDic OxiDE. — Tungstato of ammonia fonns
with bichloride of molybdenum, a deep purple-red solution, from which,
when concentrated, sal-ammoniac throws down a red compound, so that
the liquid itself retains only a pale yellow colour. The precipitate col-
lected on a filter and washed, first with water containing sal-ammoniac,
and then with alcohol of specific gravity 0*87, and lastly pressed and
dried at a gentle heat, exhibits a dark purple colour, is permanent in the
air, and perfectly soluble in water. A dilute solution ^^ually becomes
colourless in the air, from formation of molybdate of tungstic acid; soda
precipitates molybdic oxide from it. (Berzelius.)
B. Basic Tunqstatb of Molybdic Oxide and Ammonia. — An
aqueous solution of A is instantaneously decolorized by ammonia, and
deposits, after a while, a white powder insoluble in water, from which
soda separates molybdic oxide. (Berzelius.)
Molybdenum and Molybdenum.
Fluoride of Molybdenum and Potasstum, with Molybdate of Pot-
ash. — In the crystallized state, composed of KO,MoO'-|-KF,MoF^-f 2Aq.
—1. Prepared by mixing an aqueons solution of hydrofluate of molybdic
acid with a warm solution of hydrofluate of potash.-— 2. To obtain the
80 VANADIUM,
compoaud free from blue oxide, which is formed with great facility,
molybdate of potash is fused with nitre, the mafis dissolved in boiling
water, and the solution supersaturated with hydrofluoric acid. In both
cases, the compound crystallizes on cooling in brilliant, colourless scales,
resembling those of boracic acid, and also very like those of the correspond-
ing tungsten compound, only smaUer. The crystals are permanent in the
air. When heated above 50® or 60°, they lose 6 per cent, of water,
assume a greyish-yellow colour, and fuse without further alteration or
decomposition to a yellowish-brown mass. When heated with oil of
vitriol, they give off hydrofluoric acid, and form at first a splendid blue
transparent mass, which afterwards becomes colourless. The crystals
dissolve in boiling water and separate again as the liquid cools. (Ber-
zelius.)
Cryttallized. Berzelius. Or :
2K 78-4 .... 26-20 .... 26-27 KO 47*2 .... 15-78
2Mo 96-0 .... 32-08 .... 30-53 MoO« .... 720 .... 2406
4F 74-8 .... 25-00 .... KP 57*9 .... 19*35
40 32-0 .... 10-70 .... MoF» .... 104-1 .... 34-79
2H0 .... 18-0 .... 6-02 .... 6-00 2H0 .... 180 .... 602
299-2 .... 10000 .... 299-2 .... 100-00
Other Compounds of Molybdenum.
With manganese, tin, lead, iron, nickel, copper, gold, and platinum,
to which metals the molybdenum imparts infusibility, brittleness, and
whiteness.
Chaptbb XX.
VANADIUM
Sefstrbm. Fogg. 21, 43; also Schw. 62, 310.
Berzelius. Fogg. 22, 1; also Schto, 62, 323; 63, 26.
Johnston. N, Edinb. J. of Se. 5, 166 & 318; also Schw. 63, 119; 64, 88.
Stnoktmes: Vanad, Vanadin.
History, Del Rio, in 1801, found that the brown lead-ore of Zimapan
consists of oxide of lead and the acid of a metal differing in its characters
from chromium; to this metal he gave the name of Erythronmm, Collet
Descotils {Ann, Chim, 53,260) pronounced this metal to be nothing more
than chromium, a view which was afterwards adopted by Del Rio himself
(OiJh. 71j 7), and generally received as true. In 1830, Sefstrbm found
VANADIUM. 81
that the black powder which remains behind after dissolving the bar-iron
obtained from the Taberg ore in hydrochloric acid^ contains, besides other
substances, a pecaliar metal, which he likewise found in still larger quan-
tities in tbe cinder produced in the conversion of the same iron into
wrought iron. To this new metal he gave tbe name of Vanadium, from
Vanadis, a cognomen of the Scandinavian goddess Freia, Subsequently,
Wohler proved that tbe lead-ore of Zimapan consists of vanadiate of lead,
and consequently tbat Del Rio*s Erythronium is really Vanadium, For
the more exact investigation of the properties of this metal, we are
indebted to Berzelius, from whose writings, excepting where it is other-
wise expressly stated, the wbole of the following description is taken.
Sources, Kb vanadiate of lead (Del Rio, A. GeM, 2, 695; Wohler,
Pogg, 21, 49; Johnston, Sckw. 63, 119); as vanadiate of copper (Hess,
J, pr, Chem, 14, 52); further, in small quantities, in an unknown combi-
nation, in the iron-ore of Taberg (Sefstrbm); in the slags of the blast-
furnaces of Vordenberg in Steiermark, to the amount of 0*3 per cent.
(Schrotter, Pogg, 46, 311); in the bog iron ore of Steinlade in Goslar,
amounting to less than 0*2 per cent. (Bodemann, Fogg, 55, 633); in
the bituminous marl slate of Mansfeld, and in the blue slag obtained
from it in tbe reduction of the copper ^Kersten, Fogg, 51, 539; 53, 385;)
in tbe slag obtained in smelting the oituminous marl slate of Sanger-
hausen in Thiiringen; also in that of Kichclsdorf in Kurhessen, especially
in the blue and black slags, and less abundantly in the brown or grey
varieties; also in the refined copper from tbe same source (Kersten, Fogg,
52, 629); in an iron-ore from Maxen near Pima, and in the slag and pig-
iron obtained from smelting it, at tbe Frederick- Augustus works (Kersten,
Fogg, 59, 121); and lately in an iron-slag from Staffordshire, by Deck
{Fkaitn. Centr. 1848, 782; Chem, Gaz, 1848, 298); in impure pitchblende
(Wohler, Ann. Fharm. 41, 345; Fogg, 54, 600), apparently os vanadiate
of lime, wbicb penetrates the pitcbblende in brick-red, highly brilliant,
lamellar veins (Ficinus, J, pr, Chem. 26, 35); in bydrophite from the
Taberg, to the amount of O'l per cent. (Lagerhielm, Jahresber 20, 216);
in vanadic bronzite from Bracco {vid. Bronzite, III., 404) to the amount
of 34 or per cent. (Schafhautl.)
Freparation, — 1 . By exposing vanadic acid in a charcoal crucible to
the strongest heat of a blast-furnace. The inner portion of the mass
remains in the form of porous suboxide; the exterior only showing traces
of reduced vanadium. (Berzelius.) Johnston obtained the metal partly in
a coherent state.— 2. Fragments of vanadic acid are arranged in layers
in a porcelain crucible, with about an equal quantity of potassium, also
in small pieces. The cover of the crucible is then fastened down with
wire, and the whole heated till rapid reduction takes place, attended with
vivid incandescence; the vanadiate of potash is then separated by water
from the reduced, pulverulent vanadium, — 8. A bulb is blown in the
middle of a glass tube, and partly fiUed with terchloride of vanadium; the
terchloride is then saturatea with dry ammoniacal gas free from atmo-
spheric air; and the bulb heated by means of an argand spirit-lamp, the
stream of ammoniacal gas being still continued. Reduction is instantly
effected, the volatile chloride of ammonium being driven off, and the
metal left behind in the bulb.
Froperiies, Vanadium prepared by the first method is reddish-white,
VOL. IT. a
63 VANADIUM.
like bismntb, difficult to file, brittle, non-magnetic, a good conductor of
electricity, and yields a grey powder. (Johnston.) The second method
yields it in the form of a beary black powder, whicb flitters in sunsbine,
and when strongly pressed, ac<][uires metallic lustre and tbe appearance of
grapbite; it is a good conductor of electricity. When prepared by the
tbiitl method, vanadium is of an almost silvery wbiteness, higbly lustrous,
brittle, and very easily reduced to powder.
Compounds of Vanadium.
VAKADIUlf AND OXTGEN.
Vanadium remains unaltered in tbe air at ordinary temperatures.
Wben heated to incipient redness, it takes fire and bums, tbougb not
very vividly, and forms a black infusible oxide. (Berzeliua) The vana-
dium prepared by tbe first method becomes incandescent when thus
treated, and bums to an indigo-blue oxide at first, tben, after long igni-
tion, to vanadic acid. Heated to redness in oxygen goBy it burns with a
brilliant red light, and forms indigo-blue oxide, having a crystalline
texture. (Jobnston.)
The metal, as obtained by tbe first and tbird methods, is readily
oxidized by nitric and nitro-hydrocbloric acids, the product being vanadic
oxide, which dissolves in the acid, forming a blue solution. Vanadium is
not acted on by water, or even by strong boiling sulpburic, hydrochloric,
or hydrofluoric acid, boiling solution of potash, or ignited hydSrate or car-
bonate of potash, provided the air be excluded.
A. Suboxide op Vanabiitm. VO.
Preparation.'^^l. This oxide is formed by reducmg vanadic acid by
hydrogen gas, at a red heat. The same substance is obtained whether
the vanadic acid is heated just below redness, or to a low or an intense
red heat. If vanadic acid in the crystallized state after fusion be used,
it retains its cr3r8talline form or texture when converted into the suboxide.
<— 2. By fusing vanadic acid in a charcoal crucible.
As prepared by the first method, it is black, with a semi-metallic
lustre, and yields a black powder; the second method yields it in the
form of a coherent, very friable mass, having the colour and lustre of
graphite. It is infusible, even at the heat of the most powerful blast-
ihimaces, and a good conductor of electricity.
Calcoktion. Berzeliiu.
V 68-6 .... 89-56 .... 89-538
O 8-0 .... 10-44 .... 10-462
VO 76-6 .... 10000 ... 100-000
(VO = 856-89 + 100 » 956*89. Berzelius.)
Decomposed by chlorine gas with the aid of heat, the products being
terchloride of vanadium and vanadic acid.
It neither combines with acids nor alkalis, as long as it does not pass
to a higher degree of oxidation. Acids, therefore^ even at a boiling tern-
VAJiAPiq OXJDE. BS
per»tare,€lo not diasolve it, with the exception of nitric acid. Alkalis
dissolve it slowly, inasmuch as it is converted by the action of the air
into vanadic oxide. (Berzelios.)
B. Vanadio Ozidb. Vanabous Acid. VO*.
Bi-oxide of Vanadium, Vanadinoxyd, VanadinicJUe Saure.
Formation, The metal, when heated in the air, bums and forms
Tanadic oxide at first; the suboxide bums like tinder, and is converted
into the black oxide.
Preparation. 1. An intimate mixture of 19 parts (1 atom) of sub-
oxide of vanadium and 23 parts (1 atom) of vanadic acid is heated to
whiteness in a current of carbonic acid ffas. — 2. The hydrate of vanadio
oxide is ignited in vacuo. Vanadic oxide nmy likewise be obtained by
igniting vanadiate of ammonia in a retort; but the oxide thus produced
is mixed sometimes with suboxide, sometimes with vanadic acid.
Properties, Black and earthy; when prepared by the first method,
it forms a solid mass, in consequence of the fusion of the vanadic acid.
It does not fuse at the softening point of glass. It is neutral towards
vegetable colours.
Calculation. Beneliiis.
V 68-6 .... 8109 .... 81056
20 16-0 .... 18-91 .... 18*944
V0» 84-6 .... 10000 .... 100000
(V0> « 856*89 + 2 . 100 := 1056*89. BeneliuB.)
Combinations, — a. With water — ^Hydrated Vanadic Oxide.-— A
salt of vanadic oxide — ^the sulphate, for example— -is precipitated by a
very slight excess of carbonate of soda. To insure the absence of vanadic
acid, sulphuretted hydrogen must be previously parsed through the
liquid, and the excess removed by gentle heat; or the solution may be
mixed with an excess of acid, and boiled with sugar or alcohol. — The
liquid which rests above the greyish white, slowly deposited hydrate,
should be perfectly colourless. If it exhibits a blue tint, the carbonate
of soda has not been added in sufficient quantity; if it is brown, the
precipitant is in too great excess and holds some of the hydrated oxide
m solution; a green tint shows that vanadic acid is present. The
hydrate is washed out of contact of air, for which purpose the wash-
bottle of Berzelius is best adapted, the filter being constantly kept full
of water. The water is lastly poured off, and the filter pressed between
folds of bibulous paper and dried in vacuo. The hydrate prepared in
this way frequently contains a trace of carbonic acid.
Hyorated vanadic oxide is grey; but if it has attracted oxygen during
washing, or if it be kept after dr3ning, for a few hours only, in bottles
containing air, it acquires a brownish tinge. It is neutral towards blue and
red litmus. When left upon moistened litmus paper for some hours, it
reddens the paper, because it becomes partially converted into vanadic
acid. It is resolved by heat into water and the anhydrous oxide.
&. With Acids, forming the salts of Vanadic Oxide. — The oxide,
after ignition, dissolves perfectly though slowly in acids; the hydrate
dissolves more rapidly. The anhydrous salts are brown or green; the
hydrated salts either of a dark, medium, or light blue colour. Most of
them are soluble in water. The solutions, indudbg those of t^e baaie
OS
84 Vanadium.
salts, are of a beantiful blue colour of moderate intensity, and hare a
sweetish rough taste, exactly like that of ferrous salts. Solutions of
yanadic salts, when exposed to the air, frequently become green from
oxidation. When mixed with excess of ammonia, the liquid becomes
colourless, and a brown precipitate of vanadite of ammonia is formed,
which dissolves in pure water, forming a brown solution. With caustic
potash or soda, or their simple carbonates, solutions of vanadic salts give
a greyish- white precipitate of hydrated oxide, which is dissolved by an
excess of the alkali as an alkaline yanadiate, and forms a brown solution,
but is again precipitated by a larger excess of the alkali. Alkaline mono*
carbonates or bicarbonates, produce a greyish white precipitate, soluble
in excess of the alkaline bicarbonate, forming a light-blue solution.
Hydrosulphate of ammonia throws down a blackish-brown precipitate of
bisulphide of vanadium, which dissolves in excess of the precipitant,
forming a deep purple solution. — Ferrocyanide of potassium gives a yellow
precipitate, which becomes green in the air and is insoluble in acids; —
ferricyanide of potassium, a yellowish green gelatinous precipitate.
Infusion of galls forms a bluish-black mixture, resembling ink, which,
after long standing, deposits black flakes of tannate of vanadic oxide.
Hydrosulphuric acid exerts no action on vanadic salts. Zinc does not
precipitate any metallic vanadium from the solution.
c. With Salifiable Bases, forming the salts of yANADous acid;
yANADTTEs. — The compounds with the more soluble alkalis are obtained by
dissolving the oxide in their solutions; the other salts, which are all inso-
luble in water, are produced by double decomposition, in the form of pul-
yerulent precipitates. — With the alkaline monocarbonates, yanadic oxide
forms a brown solution, which contains a bicarbonate bjs well as a vanadite
6f the alkali. — The salts of yanadous acid are dark brown oi* black. —
When moistened or covered with water, or dissolved in it, they assume
a green colour, and are rapidly converted by oxidation into salts of vana-
dic acid, the insoluble salts generally becoming soluble; the dark-brown
aqueous solution of the alkaline vanadites is decolorized by this action,
the change proceeding from the top to the bottom, and the liquid not
turning green. The alkaline vanadites in solution are coloured blue by
acids, from formation of double salts; purple-red by hydrosulphuric acia,
from production of a bisulphovanadiate of the metal; and blackish-blue
by tincture of galls.
Oxides intermediate between Vanadic Oxide and Vanadic Acid.
To be regarded probably as compounds of yanadic oxide with different
quantities of vanadic acid.
1. Furple Oxide of Vanadium. — When hydrated vanadic oxide,
which has been kept for 24 hours in loosely closed bottles containing air,
is shaken up with water and filtered, a brownish-green solution of a mix-
ture of the purple and green oxides is obtained. If the hydrate which
remains on the filter be washed with a fresh portion of water, it colours
the liquid dark-brown; but to a third quantity of water it yields the purple
oxide only, giving rise to a fine deep purple solution, which remains unal-
tered in close vessels, but when exposed to the air becomes first green,
and then yellow. — When the hydrate on the filter has ceased to impart
any colour to the wash-water, it is merely necessary to expose it to the
air for a while, and it will yield the same results with water as before.
(BerieliQs.)
OXIDES OF VANADIUM, 85
2. Green Oxide of Vanadium. V0\ 2 VO', — a. When the sub-ozide
prepared by the first method (p. 82) is exposed to the air, it slowly forms
a small quantity of green oxide, the change taking place with greater
readiness, the lower the temperature at which the suboxide was produced.
b. An intimate mixture of 1 part (1 atom) of suboxide and 6 parts
(5 atoms) of vanadic acid heated to fusion, yields a dark green glass,
which, after being reduced to powder, gradually dissolves in water^
forming an opaque green solution. VO -h 5 V0'=2( VO', 2 VO'). A simi-
lar glass is produced by fusing together 5 parts (one atotn) of yanadio
oxide with 11 parts (2 atoms) of ranadic acid.
c. When moist hydrated vanadic oxide is left to dry in the open air— -
whereby it is first turned brown, and afterwards green — ^then introduced
into a small bottle, and the bottle completely filled with water and closed^
an opaque green solution is obtained, which, when filtered and evaporated
in vacuo over oil of vitriol, yields a black, amorphous, fissured mass, per-*
fectly soluble in water.
d. On mixing aqneous solutions of salts of vanadic oxide free from
excess of acid, and of an alkaline vanadiate, a dark green solution is
obtained. Thus :
V0«, 2S0« + 2(K0, V08) = 2(K0, S0») + V0», 2V0«.
A portion of the green oxide formed, separates if the solutions are
at all concentrated, because it is but sparingly soluble in water con-
taining another salt; the rest may therefore be precipitated, for the most
part, by the addition of sal-ammoniac. The precipitate is insoluble in
absolute alcohol, but dissolves in spirit of specific gravity 0*86. An
aqueous solution of the green oxide, diluted sufficiently to render it trans-
parent, exhibits a beautiful grass-green colour. — A small quantity of
potash deepens the tint. The solution, if not too dilute, may be evapo-
rated to dryness; whereas when very dilute, it acquires a yellow colour
from formation of vanadiate of potash. The residue from the former re-
dissolves in water, forming a green solution, and gives green precipitates
with salts of the earths and of the heavy metals. The potash compound
may be regarded as a mixture of vanadite and vanadiate of potash. —
A larger addition of potash precipitates vanadite of potash from the green
solution if the liquid be gently heated, because that salt is insoluble in
water containing potash, while vanadiate of potash remains in solution.
Ammonia likewise forms a green mixture with an aqueous solution of
the green oxide; carbonate of ammonia acts in the same manner; whereas
carbonate of potash or soda colour the solution brown, without precipi-
tating it. (Berzelius.)
3. TeUovhgreen Osnd€ of Vanadium. VO', 4V0'.— Formed when a
saturated solution of a salt of yanadio oxide is precipitated by an alka«
line bivanadiate :
e.g. V02,2SO* + 2{KO,2'VO») =:2(KO,SO^ + V08,4VO».
The compound when dry, resembles the green oxide; it is, however, more
sparingly soluble in water, imparts to it a more yellowish-green colour,
4ind is more completely precipitated from the solution by sal-ammoniac.
(Berzelius.)
4. Orange-yellouf Oxide of Vanadium. — Formed by exposing to the
air an aqneous solution of the purple, green, or yellow-green oxide,
containing more than one per cent, of oxide. If the oxide is dissolved
|n a larger quantity of water, it is wholly converted into v^ioiuii^ AcicL
86 VAKADIUM.
The colour of tbe liquid passes from green into yellow, and then into
orange, and when evaporated at a gentle heat, yields pale orange-yellow
crystals, which are soluble in 22^ parts of water, and form an orange-
coloured solution. When heated, the crystals give off water and become
green. (Berzelius.)
C. Vanadic Acid. VO',
Vanadsdure, Vanadinsaure, Acide vanadique.
Formation, — By long continned heating of the metal or of one of its
lower oxides in the air; by oxidizing the i»me sobetanoes with nitric acid,
aqua-regia, or nitre.
Preparation. — a. From the cindtr of ike Taberg iron, — 1. This sub-
stance is pounded finely enough to enable it to pass through a hair sieve;
and since the iron granules prevent its being more finely pulverisEed, the
powder is first moistened with water in a basin, then digested in nitrie
acid, warmed, and stirred up till fresh acid no longer produces any oxidizing
action. The mixture is then evaporated to dryness, and the residue
ignited in an iron pot, after which it is finely pounded, elutriated, and
dried on a filter. Three parts of this powder are then intimately mixed
with 2 parts of nitre and one part of (ory?) carbonate of soda, by passing
the whole three times through a sieve, and the mixture is ignited in a
covered cast-iron pot for four hours, at as high a temperature as the vessel
will bear. The resulting dense solid mass is then reduced to powder,
boiled in a silver vessel with repeated quantities of water, and the solution
exactly neutralized with nitric acid, purified by previous boiling from all
traces of hyponitric acid, which would reduce the vanadic acid to the state
of vanadic oxide. The liquid is then filtered from the precipitated silica
(which if it exhibits a bnck-red colour, must be freed from the adhering
vanadium by digestion in ammonia, and subsequently in boiling water);
the filtrate mixed with nitrate or acetate of lead; the resulting precipitate
washed, pressed dry, repeatedly agitated with fresh quantities of strong hydro-
chloric acid; alcohol added; and the mixture heated for some hours nearly
to the boiling point of the alcohol, and then thrown on a filter. The blue
filtrate contains — besides bichloride of vanadium — ^phosphoric acid, alu-
mina and zirconia. It is evaporated to dryness in a retort; the residue
dissolved in water; and the solution mixed with nitric acid, then saturated
with carbonate of potash, again evaporated to dryness, and the residue
ignited in a platinum crucible till it is perfectly fixed. The fused mass
iSter cooling is dissolved in the smallest possible quantity of water, and
the vanadic acid precipitated in the form of vanadiate of ammonia by the
introduction of a large piece of sal-ammoniac into the cold solution. The
salt is then washed on a filter with solution of sal-ammoniac, to remove
phosphoric acid, afterwards purified from sal-ammoniac by means of
alcohol, and lastly ignited in an open vessel to obtain vanadic acid, or in
a covered crucible if vanadic oxide is required. (Sefstrom.)
According to Berzelius, the vanadic acid thus prepared, obstinately
retains a portion of silica, which dissolves with it both in acids and in
alkalis. To remove this impurity, the vanadic acid is dissolved in oil of
vitriol, hydrofluoric acid added, and the mixture evaporated to dryness:
by this means fluoride of silicium is first driven off, and ttien the sulphuric
acid.
2. Berzelius ignites the flnely powdered cinder with its own weight
of nitre and <^ouble that quantity of carbonate of soda; exhausts the mass
VANADIC ACm. 87
with boiling water; neutralizes the filtrate with nitric acid; precipitates
with chloride of barium or acetate of lead; digests the washed precipitate
with oil of vitriol for half an hour; dilutes the red liquid with water;
digests the filtrate with alcohol, filters the blue liquid, and evaporates to
the consistence of a sjrnp; then adds hydrofluoric acid^ and heats the
mixture in a platinum crucible over an open fire, till the whole of the
sulphuric acid is expelled (for which a red heat is required); and mixes
the remaining vanadio acid with nitre added in small portions at a time^
till a sample of the fused mass taken out of the vessel no longer turns red
on cooling. He then treats the whole with water; filters from the insoluble
compound, consisting of alumina, zirconia, silica, and a small quantity of
vanadic acid; washes the latter slightly; and precipitates vanadiate of
ammonia from the filtrate by introducing a piece of sal-ammoniac. If the
liqnid be alkaline, some basic phosphate of ammonia is precipitated at the
same time. From the combination with the three earths above mentioned^
the yanadic acid may be eliminated by an alkaline bihydrosulphate.
6. From ike Mansfeld Copper-Slag. — One part of the slag is reduced
to powder and fused in a wrought-iron crucible, with 3 parts of carbo-
nate of soda and 1 part of nitre; the powdered greenish-yellow mass
exhausted with boiling water, and the filtrate supersaturated with hydro-
chloric acid, which turns it green and throws down silica. The whole is
then evaporated to dryness, the residue exhausted with pure (not acidu-
lated) water; the filtrate mixed with just enough hydrosulphate of ammo-
nia to precipitate it; the brown precipitate washed, dried, roasted, and then
fused with a small quantity of nitre; the mass dissolved in water; the
solution neutralised with hydrochloric acid; and lastly, vanadiate of
ammonia precipitated by sal-ammoniac. (Kersten, Pogg. 51, 539.)
c. From Pitchblende^ a mineral containing uranium, yanadium, zinc^
lead, iron, cobalt, copper, arsenic, and sulphur. Pulyerized pitch-
blende is fused with its own weight of nitre and carbonate of soda, and
the mass exhausted with repeated quantities of boiling water. The
filtrate is then exactly neutralized with nitric acid (an excess is imme-
diately discovered by the yellow colour which it imparts to the liquid);
precipitated with chloride of barium or acetate of lead; the washed
precipitate decomposed by boiling with dilute sulphuric acid; the yellow
filtrate, which contains yanadic and likewise arsenic acid, neutralized with
ammonia; and vanadiate of ammonia precipitated as before by the intro-
duction of a lump of sal-ammoniac. (Wohler, Ann, Pharm. 41, 345.)
d. From Vanadiate of Lead, — This compound likewise contains
hydrochloric acid, phosphoric acid, arsenic acid, and traces of earthy
bases. It is dissolved in nitric acid; the lead and ar^nic precipitated by
sulphuretted hydrogen; the liquid filtered; the blue filtrate boiled for a
short time to expel hydrosulphuric acid, and also to precipitate a trace of
sulphide of arsenic; the solution evaporated to dryness at a moderate heat;
the dark red residue boiled with a perfectly saturated solution of car-
bonate of ammonia, which is added from time to time; and the liquid
filtered boiling hot. On cooling, the yanadiate of ammonia crystallizes
out in white needles, which are purified by recrystallization. (Johnston.)
The yanadiate of ammonia is heated, with frequent stirring, in an
open crucible to a temperatare somewhat below redness, till the black
colour of the mass changes to dark red. (Berzelius.)
Properties, The fused acid solidifies on cooling, forming a highly
brilliant yellowish-red mass^ which is yellowish ana translucent at the
88 VANADIUM.
edges, and consists of acicnlar crystals with cavities containing aggregations
of small crystals. If the acid is mixed with vanadio oxide or any other
heavy metallic oxide, it does not crystallize after fusion, but forms a
cauliflower-like mass, and appears black; with a small quantity only of
vanadic oxide, it may be made to crystallize, but is then of a darker
colour, inclining to violet. The powder of vanadic acid is brick-red, or,
when finely divided, rusty yellow, the colour being lighter as the powder
is finer. Vanadic acid fuses at an incipient red heat, forming a liquid
which is yellowish red, according to Sefstrom, and dark brown, according
to Johnston. It then crystallizes on cooling (when it no longer appears
red-hot in difi'used daylight), and by the heat thereby developed, again
becomes ignited, a glowing ring appearing to pass inwards from the
circumference to the centre of the mass, where the light continues longest
visible. The acid is hereby considembly increased in density, so that it
can be easily removed from the crucible. Vanadic acid is not volatile.
It does not conduct electricity. It is tasteless, and reddens moistened
litmus-paper.
V
30
Calcalation.
68-6 74-08
240 25-92
Berzelius.
74-045
25-955
vo»
92-6 10000
100000
(V05 = 856-89 + 3 . 100 = 1156-89. Berzelius.)
Decompositions, — Vanadic acid, when not mixed with carbonaceous
substances, may be heated even to whiteness without giving off oxygen.
(Berzelius.) — 1. When heated with potassium, it is reduced to the metallic
state, with vivid incandescence. By exposure to a white heat in contact
with charcoal, it is reduced partly to suboxide, and partly to metallic
vanadium. (Berzelius, Johnston.) Before the blowpipe, on charcoal, it
first fuses, and is then reduced to suboxide having the appearance of
graphite; no metal is obtained by the addition of carbonate of soda.
(Berzelius.) — 2. By hydrogen eas, at a red heat, and even below that
temperature, it is reduced to suboxide. — 3. When dissolved in water, it
is reduced to vanadio oxide; by hydrosulphuric acid, with simultaneous
deposition of sulphur; by hydrochloric acid slowly, with disengagement of
chlorine; by phosphorous, sulphurous, and hyponitric acids, or fuming
nitric acid; by the salts of the lower oxides of many of the heavy metals;
and by organic compounds, as oxalic acid, tartaric and citric acid, alcohol,
and sugar. ^-4. Hydrosulphate of ammonia colours the aqueous solution
reddish brown.
ConibincUions.^-^. With water. — Solution of Vanadic Acid, — One
part of the acid dissolves in about 1000 parts of boiling water. If the
powder is agitated with water, a yellow milk is olftained, from which the
undissolved portions of the acid are not deposited till after several days,
and without being converted into hydrate. When the yellow, tasteless
solution, which is acid to test-paper, is evaporated, it deposits the greater
part of the acid in the anhydrous state in red rings round the sides of the
basin; ultimately, however, by the reducing aetion of the dust in the
air, a few hydrated crystals of the orange-coloured oxide (p. 85), distin-
guished by their greater solubility, are produced. (Berzelius.) Hydro-
sulphuric acid precipitates from the solution a mixture of vanadic oxide
and sulphur.
VANADIAtfiS. 89
5. With stronger acids. — ^Vanadio acid readily dissolves in stronger
acids, forming yellow or red solutions, which are often rendered colourless
by boilinff, and yield, on evaporation, red or yellow, partly crystallized
compounds, having a powerfully astringent, and subsequently acid taste,
resembling that of ferric salts. The acid solutions, if completely saturated
with vanadic acid, deposit, on being boiled and evaporated, a brownish
red nncrystallizable precipitate containing an excess of vanadic acid.
When exposed to the air, the solutions gradually assume a green colour,
probably from the reducing action of dust which falls into them. By
hydrosulphurio acid, oxalic acid, tartaric acid, alcohol, sugar, &c., they
are turned blue, from formation of eslts of vanadic oxide. Alkalis pro-
duce in them a rusty brown precipitate, which dissolves in excess of the
alkali, forming a yellow or brown solution. Hydrosulphate of ammonia
gives a brown precipitate of tersulphide of vanadium, soluble in excess of
the precipitant, and forming a reddish brown solution. Ferrocyanide of
potassium produces a beautiful green precipitate; tincture of galls, after a
while, a blackish blue precipitate.
c. With Salifiable Bases, forming Salts called Vanadiatbs. — The
normal salts of this acid are mostly yellow; but those of the alkalis, and
of zinc, cadmium, and lead, may likewise be obtained in an isomeric
colonrleBS state. This decolorization is produced by heating the solid salt
in a watery liquid, or the aqueous solution of that salt, to a temperature
just below 100^. It often occurs also at ordinary temperatures, after a
longer lapse of time, especially if the solution contains free alkali or alka*
line carbonate. The oivanadiates, when in large crystab, exhibit an
anrora-red colour; smaller crystals, a yellow tint. The vanadiates have
no peculiar taste that can be supposed to proceed from the vanadic acid.
They sustain a red heat without alteration, unless the base is volatile or
decomposible. Most of them dissolve readily in water, but with less facility
in water containing excess of alkali, or sal-ammoniac and other salts; the
rest are sparingly soluble; they do not dissolve in alcohol. The aqueous
solution is coloured red by the stronger acids, but freauently becomes
colourless again after a while. When a mixture of this kind, containing
but just enough of the stronger acid to satnrate the base, is evaporated, it
deposits a red mass, which is a very difficultly soluble acid salt of vanadic
acid. If the stronger acid is in excess, the substance which separates is a
compound of that acid with excess of vanadic acid. The vanadiates give
orange-red precipitates with salts of antimonio oxide, lead-oxide, cuprio
oxide, and mercuric oxide. With infusion of nut-galls they form, after a
while, a mixture as black as ink.
Vanadic acid is insoluble in absolute alcohol, and but sparingly soluble
in bydrated alcohol.
D. PjBRyANADio Acid}
An aqueous solution of vanadic acid forms a bright red mixture with
a solution of peroxide of hydrogen. (Barreswil, Compt rend, 16, 1085.)
Carhonate of vanadic oxide does not appear to exist in the free statei
but only in combination with alkaline carbonates,
90 TANADIUH.
Vanadium and Boron.
BoBATB OP Vanadic Oxide. — Sulphate of vanadic oxide yields with
borax a grejisli white precipitate, insoluble in water, but soluble in an
aqueous solution of boracic acid, with which it forms a blue liquid, rapidly
changing to green when exposed to the air. (Berzelius.)
Vanadium and Phosphorus.
A. pHOflPHiDB OF Vanadium. — Vanadium heated to redness in the
vapour of phosphorus, does not combine with it. — By heating phosphate
of yanadic oxiae to whiteness in a retort with a small portion of sugar,
or in a charcoal crucible by itself, a grey porous substance is obtained,
which may be compressed into a solid mass haying the colour and lustre
of graphite.
B. Phosphate of Vanadic Oxide. — The blue solution obtained by
dissolying yanadic oxide in a slight excess of phosphoric acid, yields,
when eyaporated at a temperature below 50°, small blue crystab, which
may be purified from the colourless mother-liquid — containing nothing but
phosphoric acid — by decantation and washing with alcohol. When heated,
they leaye the anhydrous salt as a white, swollen mus, resembling
burnt alum, which, like the crystals, rapidly deliquesces in the air, and
forms a thick blue syrup. But if this salt is exposed to a white heat, it
fuses imperfectly, and cakes together to a black mass [of pyrophosphate
of yanaaic oxide?] no longer soluble in water. The crystals deliquesce
rapidly in the air. When a concentrated solution of the salt is mixed
with anhydrous alcohol, and the resulting precipitate — ^which is gelatin-
ous, ffreyish blue, and almost white when dry — is washed with the same
liquid, a salt is obtained, which is probably b<uie, does not deliquesce in
the air^ and is but partially soluble in water.
C. Phosphate of Vanadic Acid. — a. Formed by eyaporating a
solution of phosphate of yanadic oxide in nitric acid till it turns red and
eyolyes yaponrs of nitric acid. On slowly coolinff the liquid, a lemon-yel-
low crust is deposited, consisting of small crystaUineg rams. The colour-
less mother-liquid yields, on eyaporation, an additional quantity of this
compound* It is pnrified from adhering nitric acid by rinsing with cold
water. When its water of crystallization is expelled by heat, it assumes
a straw-yellow colour. It dissolyes yery slowly in water, forming a
lemon-yellow solution.
h, Dj dissolving yanadic acid in phosphoric acid, a red solution is
obtained which^ on eyaporation^ yields a red deliquescent mass.
Vanadium and Sulphur.
A. Bisulphide of Vanadium. — Vanadous Sulphide; SulphowmO'
dous Acid. — Vanadium does not combine with sulphur when heated in
contact with it, or when ignited in its yapour. — 1. Suboxide of yanadium
is heated to full redness in a current of hydrosulphuric acid gas. In thi9
BISULPHIDE OF VANADIUM. 91
firoceaa, water is formed^ and hydrogen gai and even sulpHur set free.
Protosnlphide of vanadium appears to be the first product, which then
absorbs salphor from the remaining hydrosulpharic acid, till it is con*
Terted into bisulphide. At first : VO + HS=VS + HO; subsequently:
yS + HS=VS' + H.l Vanadic oxide ignited in hydrosulphurio acid gas
is first reduced to suboxide with semration of sulphur and formation of
water. [V0»+HS=V0 + H0 + S7]— 2. A salt ofvanadic oxide is mixed
with an alkaline hydrosulphate in excess, till the precipitated sulphide of
ranadium is again dissolved: the sulphide is then precipitated by suU
phurio or hydrochloric acid. The alkaline hydrosulphate should not con-
tain any excess of sulphur, otherwise tersulphide of vanadium mixes
with the precipitate. Bisulphide of vanadium thus precipitated is brown
at first, but turns black after being collected into a mass. It may be
washed and dried without sufiering decomposition.
It is black, and caked together, and when submitted to pressure
acquires lustre, but not the metaJlic lustre: it yields a brown powder.
Calculation. BerzeliuB.
V 68-6 .... 68'19 .... 68-023
28 S2*0 .... 81-81 .... 31-977
VS» 100-6 Z 10000 Z 100000
When heated in the air, it bums with a blue sulphurous flame, leaving
a pellicle which is blue at the edges and purple in the centre; after pro-
longed exposure to heat) fused vanadio acid is obtained. It is converted
by nitric or nitro-hydrochlorio acid into sulphate of vanadic oxide. It
is not afiected by hydrochloric or sulphuric acid. That which is prepared
by the first method is insoluble in solution of caustic potash or hydrosul-
pbate of potash; but that which is obtained by the second dissolves therein
with a purple colour, and in a boiling solution of carbonate of potash,
with a brownish yellow colour.
C(yndnnaXwM, — a. With Boracio acid.^-5. With more basic metallic
sulphides, forming compounds called Sulphovanadites. The soluble com-
pounds with the alkali-metals are obtained either by saturating an alka-
Une vanadite with b vdrosulphuric acid : KO,VO'^+3HS=KS,VS*-|-3HO,
or mixed, either with an alkaline monohydrosulphate, or with some other
salt — by dissolving hydrated vanadic oxide in an alkaline byhydrosulphatei
or by mixing a sut of vanadic oxide with an alkaline binydrosulphate.
e, ff., V0« + 2(KS, HS) = KS, VS? + KS + 2H0 ;
and : V0», 2SO» + 3(KS, HS) = KS, V8> + 2(K0, S0») + 3HS.
Hence, when a salt of vanadic oxide is used, half the hydrosulphurio
acid is set free, so that an alkaline monohydrosulphate or a metallic
protosulphide would suffice. The vanadic salt must be free from excess
of vanadic acid, and the alkaline hydrosulphate free from excess of
sulphur, to avoid the formation of a compound of tersulphide of vana«
dium with the alkali-metal. — The insoluble sniphovanadites aro obtained
by double decomposition. — These compounds in the anhydrous state are
black. The sniphovanadites of ammonium, potassium, and sodium, form
with water beautiful purple solutions, which resemble the alkaline per*
manganates, but are rendered turbid by the presence of foreign heavy
metallic sulphides. The sniphovanadites of barium, strontium, and calcium
are reddish-brown, and but sparingly soluble in water*
bi VANADIUM.
B. TersclpHidb op Vanadium. — Vanadic StUphide; Sulpkovanadic
Acid. — A solution of yanadic acid in hydrosulphate of ammonia, or an
aqueous solution of a vanadiate saturated with hjdrosu]pliuric acid gas
is precipitated bj an excess of sulphuric or hydrochloric acid. — If too
small a quantity of acid is added, a difficultly soluble compound sepa-
rates, consisting of sulphide of the alkali-metal, with a large excess of
tersulphide of vanadium. The precipitate is not decomposed by washing
and subsequent drying.
Tersulphide of yanadium, when moist, is of a lighter brown colour
than the bisulphide; when dry, it is nearly blacky though its powder is
liver-coloured.
Calcniation. Berzelius.
V 68-fi .... 58-83 .... 58-647
38 48-0 .... 41-17 .... 41-353
VS» 116-6 Z, 100-00 Z 100-000
When heated in a retort it ^ives off its third atom of sulphur, and
leaves bisulphide of vanadium. It is not decomposed by sulphuric acid.
It dissolves in caustic alkalis and their carbonates and hydrosulphates^
forming reddish brown solutions.
It combines with the more electro-positive metallic solphides, forming
a class of sulphur-salts called Svlphovanadiates.
Preparation. 1. An alkaline vanadiate dissolved in water is satu*
rated with hydrosulphuric acid or mixed with bihydrosulphate of ammo-
nia; in the latter case ammonia is set free :
e.ff., KO, V0» + 4HS = KS,VS» + 4H0.
2. Yanadic acid is dissolved in an alkaline bihydrosulphate. In this
case, the solution likewise contains a protosulphide of the alkali-metal, or
an alkaline mono-hydrosulphate :
e, ff., V0» + 3(KS, HS) = KS, \& + 2KS + 3H0. '
3. Tersulphide of vanadium is dissolved in a solution of caustic al-
kali, or of an alkaline carbonate or hydrosulphate. When free alkali
or an alkaline carbonate is used, an alkaline vanadiate is doubtless
formed at the same time :
e. ^., 4VS5 + 4K0 = 3(KS, VS») + KO,VO».
4. Substances containing vanadium are fused with carbonate of potash
and sulphur. This process, though it yields compounds of less purity
than the preceding, serves to separate vanadium from various other com-
pounds. — 5. The insoluble snlphovanadiates, those namely, of the earths,
and heavy metals, are prepared by precipitating the corresponding soluble
compounds with the salt of an earth or heavy metal.
The sulphovanadiates in the dry state are blackish brown. The
potassium and sodium salts dissolve readily in water, forming reddish
brown solutions; the barium, strontium, and calcium salts dissolve with
difficulty; and the rest are totally insoluble. From these solutions, acids
in excess precipitate brown tersulphide of vanadium; but a small portion
of the sulphide is decomposed at the moment of precipitation by hydro-
chloric acid (scarcely any by sulphuric acid), so that the liquid appears
blue. Alcohol added to an aqueous solution prodnoes a dark-red crystal-
line precipitate.
\
SULPHATE or VANADIC ACID. 95
C. SuLPHATB OP Vanadic Oxideu—- o. Bostc Sulphate. — Dilute
sulphuric acid^ or a somewhat concentrated solution of the salt b, is
completely saturated at a gentle heat^ with hjdratcd yanadic oxide, and
the solution evaporated at a slightly elevated temperature, or in vacuo
over oil of vitriol. The blue, translucent, amorphous residue, when heated
for some time at a temperature of 100°, becomes brown, but continues
soluble in water, with which it forms a blue solution. If the solution is
allowed to evaporate spontaneouslj in the air, it turns green, and when
further concentrated, deposits a green oxide; the supernatant blue liquid
is a concentrated solution of the salt b,
b. BitulpkaU, — Yanadic acid, or vanadic oxide obtained bj igniting
vanadiate of ammdnia, is dissolved in a warm mixture of equal parts of
oil of vitriol and water, and oxalic acid added to the solution as long a«
carbonic acid is evolved; or the solution is diluted with water — hydro-
sulphuric acid gas passed through it till the whole of the vanadic acid is
reduced to vanadic oxide— and the filtrate evaporated to a small bulk.
From the pale blue crystalline crust thus obtained, which is most pro-
bably an acid salt, since alcohol removes acid from it, the acid mother-
liquor still containing a portion of salt, is decanted; the crust washed
several times with alcohol, and then left in contact with alcohol for some
time. The salt thus treated swells up, and is converted into a sky-blue
bulky powder, consisting of small crystalline scales. This powder is
thrown on a filter and washed with absolute alcohol — which acquires a
blue colour by dissolving a trace of the salt — and then dried in vacuo, over
chloride of odcium or oil of vitriol. In a warm moist atmosphere, the
dry salt deliquesces to a syrup; and if this syrup be exposed to the air at
ordinary temperatures, it slowly deposits right rhombic prisms, truncated
.at the acute summits, and having the colour of blue vitriol. The presence
of a slight excess of sulphuric acid facilitates the crystallization.
Anhydrons. Crystallized. Berzeliiu.
V0» 84-6 .... 51-4 V0» 84-6 ... 4217 .... 41-36
2S0» 80-0 .... 48-6 2SO« 800 .... 39*88 .... 4052
4H0 360 .... 17-95 .... 1812
V0»,2S0» 164-6 .... 1000 +4Aq 200-6 .... lOO'OO .... 100-00
The pulverulent salt obtained by the use of alcohol has the same
composition as the crystallized salt.
The salt when ignited in a retort yields water, then sulphurous acid,
and lastly, anhydrous sulphuric acid, leaving a residue of pure fused yana-
dic acid. Agitated with water at 10°, it remains suspended, and takes a
long time to dissolve, so that, even after twelve hours a portion still
remains undissolved. It dissolves rapidly in water at 60°, and still more
rapidly in boiling water. In warm moist air, it deliquesces more readily
than it dissolves in water at 10°. The solution is blue. Absolute alcohol
dissolves the salt imperfectly. In alcohol of specific gravity 0-833 it is
easily soluble.
D. SuLPHATB OF Vanadio Acid.— o. Botic StdpkoU.'^'F omed by
boiling a dilute aqueous solution of c till it becomes turbid, and collecting
the precipitate on a filter.
0, Buulphate. — VO', 2S0^ Formed when a solution of bisulphate of
yanadic oxide in nitric acid is evaporated to dryness. Red, deliquescent,
saline mass, which dissolves in water, yielding an almost colourless
solution.
94 VANADIUM.
e. TfnulphaU.'^YO^fSSO^ Vanadic acid u dLBSolred In a hot
mixture of oil of yitriol with half its weight of water, and the excess of
snlphnric acid expeUed at as low a temperature as possible over the flame
of a spirit lamp, the heat being removed as soon as the vapour of
salphoric acid ceases to be evolved. The salt separates in small, red-
brown, crystalline scales, which rapidly deliquesce in the air, and form
a brownish-red syrup, miscible with water or alcohol, without turbidity;
but the aqueous mixture, when boiled, deposits the salt a, while the salt d
remains in solution.
d. Acid SvlphaJte. — The above-mentioned solution filtered from the
salt a, leaves a red syrup when evaporated.
E. Borate of Bisulphidb of Vanadiitm. — ^When hydrosulphuric
acid gas is passed through a solution of quadroborate of vanadic oxide, a
transparent, dark yellowish brown solution of bisulphide of vanadium in
boracic acid is obtained, from which a small quantity of sulphuric acid
precipitates the sulphide of vanadium, decolorizing the liquid at the
same time. When exposed to the air, it graduaUy assumes a lighter
colour, passing into green, and leaves on evaponition a dark green
mixture of green oxide of vanadium, sulphur, and crystallized boracic
acid.
VaK ADIUM AND loDIMS.
HtDRATBD BiKTODIDB of VANADmif, or BX-BTDRIODATE OF VaKA-
t>io OxiDB. — ^Red-hot vanadium does not act on vapour of iodine. The
blue solution of vanadic oxide in aqueous hydriodic a^id n^idly assumes
a green colour when exposed to the air, and when spontaneously evapo-
rated, leaves a brown, semi-fluid mass, which dissolves in water, formine
a blackish brown solution, and gives off iodine vapour when treated with
oil of vitriol
Vanadium and Bromine.
Htdratbd Bibromide of Vanadium, or Bi-htdrobromatb op Vana-
dic Oxide.— The blue solution of vanadic oxide in aqueous hydrobromic
acid turns green during spontaneous evi^ration. In vacuo it dries up to
M Une gum, which, when gently heated, assumes a violet-brown colour, but
«ti]l continues almost wholly soluble in water. Alcohol precipitates the
compound from the syrupy aqueous solution in the form of a jelly, which
ji^n dissolves as the alcohol evaporatee.
Vanadium and Ghlorinb.
A. Aqueous Bichloride of Vanadium, or Bi-htdrochloratb of
Vanadic Oxide.— -a. Blue inod\/iecUion. — Vanadic acid heated with con-
centrated hydrochloric acid, dissolves as vanadic oxide, with evolution of
chlorine. To convert the undissolved portion of the vanadic acid into
oxide, and thereby effect its solution, the liquid is digested with metallic
vanadium or the sub-oxide, or with sugar or alcohol, or exposed to the
action of hydrosulphuric acid gas. The blue solution leaves on evapora-
tion a blue syrup, showing no traces of crystallisation; when completely
dried at a gentle heat, it gives off hydrochloric acid, and leaves a brown
TERCHLORIDE OP VANADIUM. fB
residue chiefly consisting of basic salt. A concentrated solution of the
bi-acid salt is not precipitated bj alcohol.
b, Broum modification. — Vanadic oxide prepared by igniting yana-
diate of ammonia in a covered crucible, is dissolved to saturation in con-
centrated hydrochloric acid. In this case, also^ chlorine is disengaged,
because the oxide contains vanadic acid mixed with it. The dark brown
solution thus obtained does not dry np by spontaneous evaporation, but
leaves a black mobile liquid, which again forms a transparent brown
solution with water. When evaporated with the ^d of heat, it gradually
turns blue; and when mixed in a sufficiently concentrated state with a
small quantity of sulphuric acid, it is immediately converted into the
blue modification without evolution of gas or precipitation.
B. Terchlobidb of Vanadium. — Perc/doride of Vanadium, — Vana-
dium at a red heat bums in chlorine gas, forming a greenish yellow
yapour which condenses to a brown red liquid. (Johnston.) — Prepared
by passing chlorine gas over a red-hot mixture of suboxide of vanadium
and charcoal. To purify the condensed dark yellow liquid from excess
of chlorine, atmospheric air dried by chloride of^^calcium is passed through
the apparatus as soon as it is cold, till it no longer smells of chlorine
but only of hydrochloric acid. As the air carries along with it small
portions of the chloride of vanadium, it is passed into a dilute solution of
ammonia to prevent any loss of vanadium. — Terchloride of vanadium is a
pale yellow liquid, whose boiling point is above 100^
Calculation. Berzeliiifl.
V 68-6 .... 39-25
Sa .....*. 106-2 .... 60-76 .... 57-64
VC1» 174-8 Z 100-00
Terchloride of vanadium may be boiled over potassium without suffer-
ing decomposition; but potassium takes fire when strongly heated in
vapour of terchloride of vanadium, forming chloride of potassium and
separating the vanadium. In the air, terchloride of vanadium emits a
yellowish red cloud, being converted by the moisture present into hydro-
chloric acid and vanadic acid, the latter of which separates in a finely
divided state; it likewise deliquesces rapidly, and forms a dense red
liquid covered with vanadic acid : a small quantity of water renders it
turbid, by separating a portion of the vanadic acid produced, which like-
wise contains traces of hydrochloric acid. With a larger quantity of
water it forms a transparent, pale y^ow solution, having the taste of
sesqnichloride of iron, whidb, in a few days, or more rapidly when heated,
becomes green and then blue, evolvinff chlorine and fumung bichloride
of vanadium, and acts as a solvent on gmd. A similar solution is obtained
by dissolving vanadic acid in cold concentrated hydrochloric acid. Ter-
chloride of yaimdiam fonns with absolute alcohol a traiumarent^ red
mixture, which, howev^, changes coloar more rapidly than the aqueous
solution, passing into green and blue, and forming hydrochloric ether.
Terchloride of vanadium, when free from water, does not dissolve either
vanadium or any other heavy metals. It remains unaltered when its
yapour is passed over a red-hot mixture of suboxide of vanadium and
charcoal.
* *
96 VANADIUM.
Vanadium and Fluorine.
A. Btfluoride of Vanadium^ and Bi-hydrofluate of Vanadic
Oxide. — The blue solation of ranadio oxide in aqneous hydrofluoric acid,
leaves on eraporation a brown mass, perfectly soluble m water; when
eyaporated spontaneously, it leaves a menish sjrup, from which green
crystals are deposited. The crystals dissolve in absolute alcohol, yield-
ing a greenish solution which is turned blue by hydrosulphurio acid.
Bifluoride of vanadium combines with the fluorides of potassium and
sodium.
B. Ter-fluoride of Vanadium and Ter-htdrofluate of Vanadic
oxide. — When a mixture of fluoride of sodium and vanadiate of soda is
heated with oil of vitriol, nothing but hydrofluoric acid is disengaged,
the vanadic acid remaining with the acid sulphate of soda. Moderately
warm hydrofluoric acid readily dissolves vanadic acid, forming a colour-
less solution, which, if evaporated below 40**, leaves a colourless mass of
salt perfectly soluble in water. The salt loses part of its acid when
strongly heated, yielding a red mass which still forms a colourless solu-
tion with water; at a still higher temperature, the whole of the hydro-
fluoric acid is expelled, leaving pure vanadic acid.
Vanadium and Nitrogen.
A. Nitrate of Vanadic Oxide. — Vanadium, suboxide of vanadium,
or hydrated vanadic oxide, is dissolved in nitric acid. The oxide present
in the blue solution thus obtained does not absorb more oxygen from the
nitric acid, even at a boiling heat; but when spontaneously evaporated,
it becomes green, ultimately decomposing the nitric acid, and drying up
to a red mass of vanadic acid, which still retains a portion of the nitrio
acid.
B. Nitrate of Vanadic Acid. — ^Dilute nitric acid dissolves a small
quantity of vanadic acid; the yellowish solution, when spontaneously
evaporated, leaves a reddish mass, from which water still dissolves out a
small quantity of nitrate of vanadic acid.
C. Vanadite of Ammonia. — To the gently heated solution of a salt
of vanadic oxide, ammonia is added in excess till the precipitate first
produced is again dissolved with a blackish brown colour. The solution
is then allowed to cool slowly in a well closed vessel. The vanadite of
ammonia separates as a brown crystalline powder, leaving the super-
natant ammoniacal liquid colourless. The salt dissolves in water, forming
a brown solution, and is again precipitated in the form of a brown powder
by ammonia. If the aqueous solution is evaporated in vacuo over
chloride of calcium, ammonia is evolved, and a brown mass left, which is
no longer soluble in water.
D. Hypovanadiate of Ammonia. — A compound of ammonia with
yanadous acid and vanadic acid. When a solution of hydrated vanadic
oxide in carbonate of ammonia is exposed to the air in a tall narrow
VANADUTB OF AMMONIA. ^J
cylinder; blackish green^ radiating crystals are depbsited attlie bottom of
the yessel. Caustic ammonia, and carbonate of ammonia, added to the
green aqueous solution of the green oxide^ form a green mixture.
E. VAyABiATB OF Ammonia. — a, Monovanadiate. — «. White modi-
4cation. — 1. The reddish yellow solution of bivanadiate of ammonia^
prepared by digesting yanadic acid with ammonia in a close yessel, is
supersaturated with ammonia, and the yellow mixture warmed till it
becomes colourless. The liquid is then left to eyaporate spontaneously,
or the salt is precipitated by alcohol. — 2. A lump of sal-ammoniac, more
than sufficient for saturation, is placed in a solution of monoyanadiate of
potash or soda. The yanadiate of ammonia separates almost entirely
from the solution, because it is insoluble in water saturated with sal*
ammoniac. The portion which remains dissolved may be precipitated by
alcohol, or else as sulphide of yanadium, by mixing it first with an alkaline
bihydrosulphate and then with an acid; The white crystalline powder is
washed first with a saturated solution of sal-ammoniac, and then with
alcohol of 60 per cent.; after which it is dissolyed in boiling water con-
taining ammonia, the solution cooled to the crystallizing pointy and the
salt dried at a temperature between 20° and 30°.
Colourless, translucent, crystalline-granular crust.
The CryfialUzed tali dried at 60°. Berseliafl.
NH3 170 .... 14-33
VO» 92-6 .... 7808 .... 77.59
HO 9-0 r59
NH<0,yOS .... 118-6 Z. 10000
The salt, when moderately heated, eyolyes ammonia and] becomes
lemon-col ouied ; at a higher temperature, it turns brown; and when
heated to redness, evolves ammonia, nitrogen, and water, and leaves
yanadiate of vanadic oxide. If stronely ignited in a covered crucible, it
leaves a mixture of suboxide of vanadium, vanadic oxide, and yanadiate
of yanadic oxide : hence the residue imparts a green colour to water. A
boiling solution of ammonia removes the yanadic acid, sulphuric acid
dissolves out the vanadic oxide, and the suboxide is left behind. In this
case, the liberated ammonia exerts a deoxidizing action on that portion
of yanadic acid which first gives up its ammonia and is first heated; for
the reduction of the portions of yanadic acid which are last set free and
heated, the quantity of ammonia present is insufficient. The salt dissolves
yery slowly and sparingly in cold water, forming a colourless solution; but
in boiling water it dissolves more quickly, and colours the liquid yellow.
The yellow colour does not appear to arise from loss of ammonia; for it
is likewise produced when the salt is placed in contact with cold water in
a stoppered bottle, and the bottle subsequently immersed in boiling water.
The yellow solution is precipitated yellow by sal-ammoniac or alcohol, but
becomes colourless on the audition of ammonia; after which, sal-ammoniae
throws down a white precipitate. With infusion of galls, the aqueous so-
lution yields a black liquia, which may be used as a nearly insoluble ink.
fi, Yellata mod^ieaiion. — The process is the same as in the first method
for preparing the white modification — excepting that the yellow solution,
instead of being first heated till its colour disappears, is at once left to
evaporate spontaneously. Indistinct^ lemon-yellow crystals are obtained,
which dissolve in water without change of colour^ and are again precipi"
lated by alcohol.
yoL. ly. H
.J . ^ ^ s ^^ '<
. s ^ *
^ s ^ ^ s
98 VANADIUM.
5. BivanadlaU.-^l. Aqueous ammouia is saturated witli rauadie ifccid
in a bottle which is closed and warmed^ and the solution left to evaporate.
— 2. Or better: concentrated acetic acid is added in small quantities at a
time, and with frequent stirring, to an almost boiling solution of the simple
snlt, till the precipitate first formed is redissolved; and the aurora-red
solution is left to cool till it crystallizes. The salt forms aurora-red,
transparent crystals, soluble in water, from which they are again precipi-
tated by alcohol in the form of a lemon-yellow powder.
c. With excess of add — A solution of bivanadiate of ammonia mixed
with hydrochloric acid, and evaporated at a temperature between 30° and
40"* till it becomes colourless, and afterwards at ordinary temperatures,
deposits veiT small, cubical, brown grains, consisting of a mixture of acid
vauadiate of ammonia and basic hydrochlorate of vanadic oxide.
F. Carbonate op Vanadic Oxide and Ammonia. — The blue solution
of vanadic oxide in excess of bicarbonate of ammonia.
G. Bisulphide op Vanadium and Hydrosulphate op Ammonia.^
In the dry state this compound is black; when dissolved, it forms a beau-
tiful purple-red solution.
H. Tersulphidb op Vanadium -f Hydrosulphate op Ammonia.
— A solution of vanadic acid in bihydrosulphate of ammonia rapidly
evaporated, deposits a whitish grey mixture of sulphur and sulphovana-
diatc of ammonium, with excess of tersulphide of vanadium. This preci-
pitate yields, on distillation, water, sulphur, and hydrosulphate of
ammonia.
I. Basic Hydrobromate op Vanadic Oxide and Ammonia. —
Thrown down by ammonia from a solution of hydrobromate of vanadic
oxide, in the form of a greenish grey precipitate.
K. Basic Hydrochlorate op Vanadic Oxide and Ammonia.—
Ammonia gives with hydrochlorate of vanadic oxide a greenish grey
precipitate, insoluble in water.
L. Terchloridb op Vanadium -f Ammonia. — Terchloride of
vanadium rapidly absorbs ammoniacal gas, with great elevation of tempe-
rature, and is converted into a white, uncrystallizable mass, which is partly
sublimed by the heat evolved. Heated m a current of ammoniacal gajs,
it is decomposed, even below redness, into nitrogen gas, water, and metallic
vanadium (p. 81, 3).
Vanadium and Potassium.
A. Vanadite op Pota8H.<^A hot solution of sulphate or hydrochlor-
ate of vanadic oxide is mixed with a slight excess of caustic potash, and
the mixture left to cool in a close vessel, — ^whereupon brilliant, brownish^
crystalline scales are deposited, and the colour of the liquid changes from
brown to pale yellow. If sulphate of vanadic oxide has been used, the
crystals are washed, first with solution of potash, and then with alcohol,
and lastly pressed out and dried in vacuo. The salt forms a brown mass
having a pearly lustre and permanent in the air. It is very soluble in
water, ana yields an opaque brown solution. This solution is decolorized
by exposure to the air, from formation of vanadiate of potash. An excess
of potash precipitates vanadiate of potash from the brown solution, in ih^
VANADIATE OF POTASH. 99
form of a brown powder, which redissolves on the application of heat,
but again separates for the most part on cooling, so that the liquid retains
only a pale yellow colour.
B. Hypotanadiate op Potash. — See the behaviour of the green
oxide with potash (p. 85, d),
C. Vanadiatb op Potash. — a, Monovanadiate, — The colourless solu-
tion left to evaporate spontaneously, leaves first a syrup, and then a milk-
white, earthy mass. Any excess of potash present may be removed by
cold water, as the salt itself is difficultly soluble in water, especially if it
contains free potash. The salt fuses readily, forming a transparent,
yellow liquid, which on cooling solidifies in a white mass. It dissolves
slowly in cold but more rapidly in boiling water. — No yellow modification
of vanadiate of potash is known to exist.
h. BivanadicUe. — 1. The salt a is fused with vanadio acid in atomic
proportions. — 2, The salt a is boiled with vanadic acid in water. — In
both these processes monovanadiate of potash remains mixed with the
bivanadiate. — 3. Or better : to a nearly boiling aqueous solution of the
salt a, small portions of strong acetic acid are gradually added, with
constant stirring, till the precipitate first formed is redissolved. The
liquid is then filtered, if any separation of silica has taken place; the
aurora-red solution — which if too dilute must be first concentrated — ^is
mixed with alcohol; the resulting precipitate washed with alcohol, and
dissolved in boiling water; and the liquid left to cool till it crystallizes.
The crystals are dehydrated by heat.
The anhydrous salt is brick-red; fuses with tolerable facility, and
solidifies in a yellow mass on cooling. The crystallized salt appears
sometimes in orange-yellow lamin® collected together into a crust,
sometimes in lemon-yellow scales having an almost metallic lustre. The
crystallized salt dissolves sparingly in cold, bat much more abundantly
in hot water. In larger quantities of hot water it dissolves without
alteration, but a small quantity of hot water dissolves out a mixture
of monovanadiate and bivanadiate of potash, leaving a hvper-acid salt
undissolved. If the salt is previously fused or dehydrated, the hyper-
acid salt is almost always separated on treating it with water. The
hot solution as it cools, deposits the greater part of the bivanadiate,
while the monovanadiate remains dissolved. When caustic potash is
mixed with a hot concentrated solution of bivanadiate of potash, the
liquid becomes colourless, and monovanadiate of potash is formed, Bu^
if the mixture is made in the pold, the liquid becomes turbid after a
certain quantity of potash has been added, and deposits scaly crystals o{
the bivanadiate, the rest of which may be precipitated by alcohol in
the form of a yellow powder. This powder, however, is coloured green
by the action of the alcohol, and forms a dark green solution in water;
but on evaporating the solution, the characteristic yellow of bivanadiate of
potash is again produced.
Anhydrous, Crysialtized. Berzeliiu.
KG 47-2 .... 20-31 KG 472 .... 18-20) «o -«
2VG» 185-2 .... 79-69 2VO» 185-2 .... 71-39/ "" "^ ^*
3HG 270 .... 10-41 .... 10-42
KG,2VG».... 232-4 .... 10000 +3Aq 259.4 .... 100-00 .... 100-00
c. Hyper-acid vanadiate. — The substance which remains undissolved
ou treating the salt b with a small quantity of hot water.
B 2
100 VANADIUM,
D. Carbowatb op Vanadic Oxide and Potash. — ^Prepared like
the corresponding ammonia-^alt.
E. SuLPHo-YANADiTE OF PoTASSiuM.^The black compound dissolyes
in water, yielding a bright purple-red solution.
F. StTLPHOIrANADiATl OF PoTA^siUM.-^-Sepafated by alcohol from its
reddisb-bromi aqaeons solatlon, in the form of a scarlet precipitate^
which is turned orown by washing with alcohol. When the aqueous
solution is eraporated In racuo, a blackish-brown earthy mass is left
which redissolves in water.
O. SulfhItb op Vanadio Oxidb and Potash. — Sulphate of potash
dissolved in water is mixed with a slight excess of sulphate of yanadio
oxide, the mixture evaporated to a syrupy consistence, and the salt preci-
pitated by alcohol. The precipitate is lignt blue and yery soluble in water.
Or, one atom of KO,SO' is dissolved in water, together with one atom of
VO', 2S0'. The solution dries up to a pale blue, opaoue, gummy mass,
which continues soft for a long time, but at length hardens and exhibits
a conchoidal fracture.
H. Sulphate of Vanadic Acid and Potash. — An aqueous solu-
tion of monoyanadiate of potash mixed with a small quantity of sulphuric
acid and left to evaporate spontaneously, becomes first red, then
colourless, and lastly deposits very small acicular crystals collected toge-
ther into roundish masses^ which dissolve very sparingly in water, and
are insoluble in alcohol.
I. BiFLITORIDB OF VANADIUM WITH FlUORIDB OF PoTASSIUH.-*— A
blue compound^ readily soluble in water but insoluble in alcohol.
Vanadium and Sodium.
A. Vanadiatb of SoDA.-^a. Matiovanadiate.^^'PrepgLred like the
potash salt.
h. BivanadiaU. — Large, transparent, aurora- red crystals, which turn
yellow in the air from efflorescence, are more soluble in water than
the potash salt, and completely precipitated by alcohol from the aqueous
solution. Vanadic acid, when fused with carbonate of soda before the
blowpipe, sinks into the charcoal.
fi. Vatiadic acid dissolves in borax in the outer blowpipe flame, forming
ft yellow bead, which becomes green in the deoxidizing name, — or, if the
bead is tolerably saturated, brownish while hot, and green on cooling.
In the outer flame, the green colour is reconverted into yellow; but if the
anantitj^ of vanadium is small, it disappears entirely. (This character
distinguishes vanadium from chromium.)
C. Phosphate of Vanadic Acid and Soda. — An aqueous solution
of phosphate of soda and phosphat-e of vanadic oxide, evaporated with
nitric acid at a gentle heat, becomes colourless, and deposits larse lemon-
vellow grains and lumps, composed of small acicular crystals, which may
be purified from the mother-liquor by washing with cold water. The
VANADIATB OP BARYTA. 101
compoand dissolves very slowly in waier^ forming a yellow solution^
which does not a^in yield crystals on evaporation^ hut dries np to a
yellow varnish still solnhle in water.
With microcosmio salt, vanadio acid behaves before the blowpipe as
with borax.
D. BivLUOBiDB OF Vakadiitm + Flvobidb of Sodium, r-^ a blue
compoand, readily dissolved by water, bat ineolablo ia aleohol.
Vakadium and Lithium,
Vanadiatb op Lithia. — a, MonovanadicUe, — This salt crystallizes
out from an aqueous solution evaporated to a syrupy consistence, in small,
colourless needles, collected together in dense, rounded masses; it is very
soluble in water.
b. Bivanadiate, — Deposited from the yellow, syrupy solution in large,
aarora-red crystals, wbich efflorefioe in dry air, and are but very imper^
fectly precipitated from an aqueous solution by alcohol — because the salt,
though insoluble in absolute alcohol, dissolves to some extent in ordinajy
spirit of wine,
Vanadium and Babium.
A. Vanadiatb op Babyta. — a. B<mc Vanadiate, — An aqueous solu-
tion of b gives with baryta-water, after a while> a yellow precipitate
which subsequently becomes white.
(. Monovanadiate. — An aqueous solution of the colourless monovana-
diate of ammonia mixed with chloride of barium, rapidlv tarns yellow,
and yields a yellow, gelatinous precipitate, which, at ordinary tempera-
tures, becomes white after a few hours, — ^but if the mixture is heated,
immediately turns white and increases in density. The white and the
yellow precipitate have the same composition. When ignited^ the salt
loses its water of crystallization, and appears yellow while hot and white
on cooling. At a full red heat, it fuses to a yellowish brown mass resem-
bling colophony. Before ignition, the salt dissolves sparingly in water,
the white variety yielding a colourless, and the yellow variety a yellow
solution. The solution, when spontaneously evaporated, deposits small,
white, crystalline grains. The salt dissolves in oil of vitriol; fprming a
red solution.
Anhydrous, Dried at 60^ Beneliu.
BaO 76*6 .... 45-27 BaC... 76-6 .... 42*98 .... 42-25 to 43-24
VQS 92-6 .... 54-73 VO^.... 92-6 .... 5197 .... 50*90 „ 51-31
HO .:.. 90 .... 5-05 .... 5-79 „ 5-56
B»0,VO» 169*2 .... 100-00 +Aq. 178-2 .... 100*00 .... 98*94 .... 100*11
c. Bivanadiaie, — The transparent solution obtained on disaolviBg
bivanadiate of potash and chloride of barium in water, deposits, by spon-
taneous evaporation, short, orange-yellow prisms, or — if mixed with
alcohol till it is rendered slightly turbid — brilliant, lemon-yellow scales.
The compound is difficultly soluble in water.
B. SuLPHO vanadiatb op Barium. — This compound may be obtained
in the crystalHne form; it is slightly soluble in water, and can therefote
be precipitated only from concentrated solutions.
102 VANADIUM.
Vanadium and Strontium*
A. Vanadiatb of Strontia. — a. Basic Vanadiate, — Prepared like
the baryta-salt.
(. Monovanadiaie, — Similar to the baryta-salt, bat somewhat more
soluble; hence the white crystalline-granular precipitate which mono-
vanadiate of ammonia gives with chloride of strontium, does not appear
till after some time. No yellow vanadiaie of strontia is known to exist.
c. BivanadiaU. — Brilliant, orange-yellow crystals, more soluble than
the corresponding baryta-salt.
B. SuiFHOTANADiATE OP Strontium. — Resemblcs the barium com-
pound.
Vanadium and Calcium.
A. Vanadiate op LiME.^-a. Bade Vanadiate, — ^Prepared in the
same manner as the baryta compound; it is, howerer, more slowly
deposited.
h. Monovanadiate, — More soluble even than the strontia-salt; sepa-
rates in the form of a white or yellowish crust on slowly evaporating the
mixed aqueous solutions of mono vanadiate of ammonia and chloride of
calcium. It is but imperfectly precipitated by alcohol from an aqueous
solution.
c. BivanadiaU, — This salt forms large, aurora-red crystals, which do
not effloresce but are readily soluble in water.
B. SuLPHOVANADiATE OP Calcium. — Prepared like the barium com-
pound.
Vanadium and Magnesium.
Vanadiate op Magnesia. — a, MonovanadiaU, — Formed by boiling
magnesia alba with vanadic acid and water. The colourless filtrate
yields, by spontaneous evaporation in the air, a syrupy liquid, which
gradually solidifies to a dense, radiated mass, very soluble in water.
h, Bivanadiate, — An aqueous solution of this salt, when spontaneously
evaporated, deposits yellow scales; alcohol precipitates it, though not
completely, in the form of a yellow powder. The salt is difficultly
soluble in water.
Vanadium and Yttrium.
Vanadiate op Yttria. — The monovanadiate formed on mixing a
salt of yttria with an alkaline monovanadiate, separates in the form of a
yellow powder; the bivanadiate produced by using an alkaline bivana-
diate remains dissolved.
Vanadium and Glucinum.
Vanadiate op Gluctna. — Both the monovanadiate and bivanadiate
of this earth form yellow powders, wiiich dissolve sparingly in water,
producing yellow solutions.
HYDROFLUATE OF SILICA AND VANADIC OXIDE. 103
Vanadium and Aluminum.
Vanadiate of Alumina. — Resembles the glucina-salt^ but is less
soluble in water.
Vanadium and Thorinum;
Vanadiate op Thorina. — a, Monovanadiate. — Obtained by double
decomposition as a yellow precipitate^ which is insoluble in water. —
h. Bivanadiate, — A soluble salt.
Vanadium and Zirconium.
Vanadiate op Zibconia. — ^Zirconia-salts are coloured yellow by
alkaline monoranadiates and biyanadiates^ but without precipitation.
Vanadium and Silicium.
A. Silicate op Vanadic Oxide. — Precipitated as a light-grey
powder, which, when exposed to the air, assumes first a brown and then
a green colour — after which it is no longer soluble in water.
B. Phosphate op Vanadic Acid + Phosphate op Silicic Acid. —
Obtained in the preparation of yanadic acid from the cinder of the Taberg
iron (p. 86.). It may also be produced by dissolying a mixture of phos-
phate, silicate, and yanadiate of soda in nitric acid; eyaporating the
solution till a lemon-yellow^ gritty mass is obtained; mixing this with
pure water; collecting the pearly scales which appear, on a filter; wash-
ing them two or three times with ice-cold water; and pressing them dty
between folds of blotting-paper. The compound loses water when heated
and assumes a straw-yellow colour. It is readily turned green by deoxi-
dizing substances. It is decomposed by an aqueous solution of carbonate
of ammonia, with separation of silica, which, however, retains a portion
of the vanadic acid. Water dissolves it with tolerable facility, forming a
yeJIow solution, from which it again separates in crystalline scales on
lipontaneous evaporation.
Crystallized. Beneliiu.
3SiO» 93-0 .... 19'58 •... 19-6
2V0» 185-2 .... 39-01 .... 39*0
2P0» 142-8 .... 3006 .... 300
6HO 54-0 .... 11-35 .... 11*5
3SiO*,PO* + 2VO»,PO» + 6Aq. 4750 .... 10000 .... 1000
Vanadic acid containing silica likewise dissolves completely in sul-
phuric or hydrochloric acid, without separation of silica.
C. Hydropluatb op Silica and Vanadic Oxide.— jFYtjorMfe cf
Vanadium and Silicium. — The blue solution of vanadic oxide in hydro-
fluosilicic acid leaves, when rapidly evaporated, a blue substance, which,
at a moderate heat, swells up to a^le blue porous mass; if allowed to
eva^rate spontaneously, the solution turns green^ and leaves a syrupy
liquid containing crystals.
104 VANADIUM.
D. HYDROPLUA.TB OP SiLICA AND VaNADIC AcID. — SUtCO-
perfluoride of Vanadium, — HydroflaosUicio acid forms a red solation
with vanadic acid. By evaporating this solution, an orange-yellow
nncrystallizable mass is obtained, which is but psurtially soluble in water;
the solution is pale yellow. The insoluble portion forms a bulky, dark-
green mass, which, when treated with oil of vitriol, gives off fluoride of
siliciom, and dissolves^ forming a red solution.
Yanadium and Tungsten.
A. TuNGfiTATB OP Vanadic Oxide. — On mixing the concentrated
solutions of an alkaline tungstate and a salt of vanadic oxide, a brownish
yellow precipitate is formed, which is solnble to a certain extent in
water. This substance, when kept under water for a long time, dissolves
completely (as the vanadic oxide passes into tb« state oi vaatadic acid)
and forms a yellow eolation.
B. SuLPHOTUNSGATE OP Vanadiuh. — Sulphate of vanadic oxide yields
with sulphotungstate of ammonium a greyish-brown precipitate, which
dissolves in water, forming a yellowish-brown solution. This liquid,
when exposed to the air, gradually becomes turbid, and yields a deposit
chiefly consisting of sulphur.
Vanadium and Molybdenum.
' MoLYBDATE OP Vanadic Oxide. — Sulphate of vanadic oxide forms
with molybdate of ammonia a dark purple, transparent mixtnre, which,
when eraosed to the air, becomes first blue, and then yellow, but does
not yield any precipitate. Salts of molybdic oxide form yellow solutions
with vanadiate of ammonia.
Other Compounds op Vanadium.
With many of the heavy metals, as with platinum. Vanadiates of the
heavy metallic oxides heated on charcoal before the blowpipe, readily
yi^d brittle alloys of the reduced metal with vanadium.
lOS
Chaftib XXI.
CHROMIUM,
Vaaqneliii. Ann, Chim. 25, 21, and 194; also Crdl. Ann. 1798, 1, 189;
1798, 1, 276. Farther: Ann. Ohim. 70, 70.
Ricbter. Ud>er die «. (hgemt, der Chemiey 10, 30, and 11, 37. A. €fM.
5, 35L
Godon de St Menin. Ann. Chim. 53, 222.
Moasin-Poaschkin. CrelL Ann. 1798, 1, 355, and 2, 444.
John. Chromates. Sckw. 3, 378.
Berzelins. Schw. 22, 53; also Ann. Chim. Phya, 17, 7; also Lthirbwk.
1826, 2, 55, and 989; also Pogg. 1, 34.
Brandenburg. Chromic Acid and Oxides of Chromium. Sckw. 13, 274.
Scher. STord. BL 1, 190. ScSier. Nord. Ann. 1, 297; 2, 126 and 325;
3, 61 and 325; 4, 187.
Dobereiner. Chromic Acid. Schw. 22, 476. -tV. Tr. 2, 2, 426.
Meissner. GiUb. 60, 366.
Lassaigne. Ann. Ohim. Phys. 14, 299; also N. Tr, 5, 2, 250.
Berthier. Awn, Chim, Phys. 17, 5Q.
Grouvelle. Ann. Chim. Phys. 17, 349.
Thomson. Chromate of Potash. Ann. Phil. 16, 321.
F. Tassaert. Chromate of Potash. Ann. Chim. Phys. 22, 51; also Sckw.
43, 429; also N. Tr. 4, 1, 199,
Moser. Chemische Ahhandlung fiber das Chrotn. Vienna, 1824.
Otto Unverdorben. Fluoride of Chromium and Chromic Acid. ^. Tr.
9, 1, 26.
Hayes. Sill. Amer. J. 1^ 186; 20, 409.
Maus. Chromic Oxide. Pogg. 9, 127. Chromic Acid. Pogg. 11, 83.
H. Rose. Chloride and Flnoride of Chromium. Pogg. 27, 5^5. Chlo-
ride of Chromium. Pogg. 45, 183.
Peligot. Ann. Chim. Phys. 3, 12, 528.
MoWg. J. pr. Chem^.A^, 322; abstr. Ann. Pharm. 68,
Traube. Ann. Chim. Phys. 66, 87, and 165.
Stkonymbs. Chram, Chroma
History. — Discovered in 1797, ly Vauquelin.
Sources. — Not very abundant. As sesquioxide of chromium {Chrome-
ochre); as sesquioxide of chromium combined with protoxide of iron
{Chrome iron-fCone)', as chomate of lead {Bed lead-^Hxr)', also in small
106 CHROMIUM.
quantities in many specimens of meteoric iron; it likewise forms the green
or red colouriDg matter of the emerald^ and of diallage, octynolite, green-
stone, olivine; fuchsite, pyrosklerite; serpentine, pyrope, and spinelle.
Preparation. — Sesqaioxide of chromium ^sometimes mixed with one-
eighth its weight of lamp-black) is exposed m a charcoal crucible to the
most powerful heat of a furnace urged by the bellows. Richter mixed
the oxide with one-third its weight of charcoal made from sugar, and
reduced it in a luted assay crucible; Berthier exposed it alone in a char-
coal crucible for three hours to the heat of a blast-furnace fed with coke;
Vauqueliu heated chromic acid alone, or sesquichloride of chromium
mixed with oil and a small quantity of charcoal (which gave the best
result) in a charcoal crucible; Moser mixed 100 parts of sesquioxide of
chromium with 22 '5 parts o/ charcoal from sugar^ made the mixture into
a paste with linseed oil, and exposed it in a porcelain assay crucible to
the heat of the pottery-furnace at Vienna. It is vezy difficult to obtain
a solid button of chromium.
Properties. — Colour between tin-white and steel-grey ^Richter),
whitish grey (Vauquelin). Very brittle, breaking when lightly struck
with a hammer. Fracture fine grained (Richter). Texture indistinctly
fibrous (Vauquelin). Specific gravity 5*9 (Richter). Fuses with greater
difficulty than manganese. Not volatile. Non-magnetic. Berthier ob-
tained this metal in moderately compact, very hard, brittle lumps, steel-
frcy in some places, black in others. Moser obtained a steel-grey, easily
roken mass, composed of four-sided prisms. Gmelin obtained a brittle,
metallic, non-magnetic mass, with a dull grey fracture, but interspersed in
many places with tin-white crystals.
IT Berzelius (Ann, Pkarm, 49, 247) recognises two allotropio modifi-
cations of chromium. The first of these, Or^, obtained by reducing
sesquichloride of chromium, free from moisture and oxygen, with potfus-
sium, is a grey metallic powder, which inflames at a temperature between
200"^ and 300®, and bums with great splendour, yielding sesquioxide of
chromium; it likewise dissolves in hydrochloric acid, with rapid disen-
gagement of hydrogen gas. Cr/3, on the contrary, prepared in the
ordinary way by reduction with carbon at a high temperature, cannot be
oxidized by heat, by boiling in aqua regia, by ignition with potash or
nitre, or by hydrofluoric acid. Corresponding modifications may be
traced through many of the compounds of chromium.
Atomic weight of C7iromium, — 26-24 (Peligot); 26-29 (Berlin); 26-79.
(Moberg.) IT
Compounds of Chromium.
Chromium and Oxtqbi^.
IT A. Protoxide of Chromium or Chromous Oxide. CrO.
Probably occurring in Chrotne-iron'^yre and in Pyrope, Precipitated
in the form of hydrate by the action of potash on a solution of the
protochloride. Not known in the free state.
Calculation.
Cr 28 .... 77-78
O 8 .... 22-22
CrO 36 .... lOO'OQ
CHROMOSO-CHROMIC-OXIDE. 107
Combinations. — a. With Water* Hydrate op Chromous Oxide.
FormcUion and Preparation. — ^Wlien caustic potash is added to a solution
of protocbloride of chromium (p. 180)^ a dark brown precipitate of
hjdrated chromous oxide is obtained. It is very unstable^ decomposes
water^ even at ordinary temperatures^ and is converted^ almost as soon
as it is formed into chromoso-chromic oxide {q. v.) with evolution of
hydrogen (Peligot). To prevent this decomposition, Moberg (J. pr.
Chem. 43, 114; 64, 322) proceeds as follows. Protocbloride of chromium
having been prepared by reducing the sesquichloride in a current of
hydrogen gas^ the tube in which the reduction is effected is sealed at onO
end as soon as the action is over, then filled completely with boiled watery
and a small tube attached to the other end to carry off the hydrogen
which may be evolved by the action of the water on the reduced metallio
chromium, which (according to Moberg) is always mixed with the proto-
cbloride. The tube is then left to cool, and afterwards inverted in a bottle
containing recently boiled solution of potash, and the yellow precipitate
of hydrated chromous oxide which immediately separates and falls to the
bottom, is washed by means of a siphon arrangement. Lastly, the water
is poured off, and the precipitate dried in a sand-bath in a current of
hydrogen gas.
Yellow when freshly precipitated; brown when dry. May be pre-
served unaltered in dry air for three years. When ignited, it gives off
hydrogen, and the oxygon thereby separated converts the protoxide of
chromium into sesquioxide. (Moberg.)
Calculation. Mobei^.
CrO 36 .... 80 .... 79-57
HO 9 .... 20 .... 20-43
CrO, HO 45 Z. 100 Z 10000
h. With Salifiable bases : Salts of Chromous Oxide, Chromous
Salts. — The hydrated oxide is insoluble in dilute acids, but dissolves
slowly in strong acids. The salts are best prepared by mixing a solution
of the protocbloride with solutions of the corresponding potash or soda-
salts, access of air being carefully prevented. They are generally of a
red colour, sometimes inclining to blue; but slightly soluble in cold water;
more easily in hot water. (Moberg.) Like ferrous salts, they dissolve large
quantities of nitric oxide, forming dark brown solutions. Peligot* (For
the other reactions, vid. FrotoMoride qf Chromium, p. 131.)
IT B, Chromoso-chromio Oxide. Cr*0*.
Peligot's Detttoxide or Oxyde Magnetique,
According to Peligot, the hydrate of this oxide is formed in greater
or smaller quantity, on bringing the protoxide in contact with water
(that is to say, at the moment of its precipitation); for, on introducing a
solution of the protocbloride into a jar filled with mercury, and then
passing up a solution of caustic potash, a quantity of hydrogen gas collects
at the top as soon as the brown oxide makes its appearance. To complete
the decomposition, however, a boiling heat is required. After washing
with hot water and drying in 7acuo, this oxide has the colour of Spanish
tobacco. It is but feebly attacked by acids. When heated it loses water,
and is converted into chromio oxide, the change being accompanied by
|08 CHROMIUM.
mcandeseenee and erolation of hydrogen, in eonseqnenee of tbe higher
oxide being formed at tho expenjse of the water of hydration. From
varionB analysee^ Peligot concindei that tbe hydrate i« composed of
Cr»0*+HO. T
C. Chbomio Oxidb or Ses(^uio^idb of Chbomium. Cr'O',
Oreen Oxide ofOhromivm^ Chrom^^n.^-^VoTmetlj alao Chromoxydul,
Protoxyde de Chroma — Found native in an impure state, aa Chroma
Ockre^
Formation, — 1. At ordinary temperatures chromium remains unal-
tered in the air, even when moist. (Richter.) When it is heated in moist
air, a crust of sesquioxide slowly forms on its surface. (Vauquelin.) —
2. Red-hot chromium decomposes a current of aqueous yapour passed
over it, hydrogen gas being copiously evolved, and the green oxide
formed. (Regnault.) — 3. The metal dissolves with great facility in a hot
mixture of 1 part of oil of vitriol and 20 parts of water, hydrogen gas
being rapidly disengaged. (Regnault, Ann. Chim. Pkys, 62, 357.) It
dissolves in aqueous nydrofluoric acid, especially when heated, hydrogen
£as being evolved. (Berzelius.) It dissolves readily in oil of vitriol, with
disengagement of hydrogen, and slowly in hydrochloric acid. (Gmelin.)— -
4. It is dissolved, but very slowly, by not nitric acid (Vauquelin), or by
nitro-hydrochloric acid (Richter). — 5. When chromic acid is ignited or
treated with deoxidizing substances, sesquioxide of chromium is produced.
Preparation»^-l. From Chrome^iron ore (a mixture of sesquioxide of
chromium .and protoxide of iron with magnesia, alumina, and silica).-—
1 . Preparation ofChromaie ofpUaih, — Vauquelin mixes 2 parts of chrome-
iron ore with one part of pure nitre; reduces the mixture to fine powder;
ignites it strongly and for a considerable time in an earthen or iron cruci-
ble; exhausts the ignited mass with boiling water; and treats the insoluble
portion with hydrochloric acid, whidi dissolves magnesia, alumina, silica,
and sesquioxide of iron, and leaves any nndeoomposed chrome-iron ore
behind; this residue is again ignited with one-fourth of its weight of
nitre, and exhausted with water. The treatment with nitre and then
with water and hydrochloric acid may be repeated till the whole of the
mineral is decomposed. — The aqueous solutions (a), obtained by exhaust-
ing the mass with water, after ignition with nitre, and containing chro-
mate (nitrate, nitrite), silicate, and aluminate of potash, are collected into
one, in order to be further treated. — Trommsdorff, {N, Tr. 18, 1, 225)
uses equal weights of chrome-iron ore and nitre, whereby a more com-
plete decomposition is effected. — Nasse (iSc/tir. 43, 339) projects a mix-
ture of 3 parts of chrome-iron ore, 4 parts of nitre, and 2 parts of cream
of tartar, by small portions at a time, into a red^iot iron erucible, and
exposes tiie mass, after it has ceased to detonate, to a strong red heat for
two hours; he then exhausts it with water, and treats the insoluble resi->
due twice in the same manner, before digesting it with hydrochloric acid.
The decomposition is probably more complete in this case than when
nitre alone is used. IT Jacquelin {Ann, Chim. Phy%, 21, 478) 'recom-
mends the use of a lime-salt instead of nitre, and proceeds in the fol-
lowing manner: a pulverized mixture of chrome-iron ore and chalk is
ignited, the surface being constantly renewed by stirring; the mass
]g;poBnd down with hot water, and mixed with sulphuric acid till it
CHROMIC OXIDE. 109
acqnirefil &ti acid reaction; and the sesqnioxide of iron precipitated by
the addition of a small anantitj of chalk. In this manner a solution is
obtained, consisting of bichromate of lime, contaminated with bat a small
anantity of sniphate, from which the various salts may be prepared by
donble decomposition. IT
2< Preparation of the Chromic oxide^-^a. Vanqaelin precipitates the
alumina and silica held in solution by the potash, by exactly neutralizing
the alkali in liquid (a) with nitric acid, the acid being added in small
portions at a time till the lemon-yellow colour of the liquid begins to
change into reddish yellow: he then filters; evaporates to the crystal-
lizing point; dissolves the resulting crystals of chromate of potash in
water; filters; and precipitates chromate of mercurous oxide by adding
nitrate of mercurous oxide to the filtrate. The mercury-salt, after being
purified with water, and dried, is thoroughly ignited in a porcelain or
glass retort; whereupon mercury and oxygen are driven off, and chromic
oxide left behind. — Moser omits the neutralizing of the liquid (a) with
nitric acid, to avoid any admixture of nitre, and endeavours to purify the
salt by ciystallization alone. — Trommsdorff, (iV. Tr, 2, I, 366) neutralizes
with acetic acid instead of nitric; filters; evaporates to dryness; and
removes the acetate of potash by spirit containing 80 per cent, of alcohol.
•^6. Vauquelin mixes the solution (a) with excess of sulphuric acid; filters;
converts the chromic acid into sesqnioxide of chromium by a current of
sulphuretted hydrogen gas; precipitates the latter, after filtration, by
adding an equivalent quantity of potash (or better, of ammonia); washes
the precipitated hydrate, ana lastly ignites it. — Nasse converts the chro-
mate of potash into a salt of chromic oxide, by boiling with common salt
and sulphuric acid; evaporates the liquid to dryness; dissolves in water;
and precipitates the hydrated chromic oxide by supersaturating with
an alkali. — c. Duflos {Br. Arch. 23, 1 66) passes sulphurous acid gas
through the solution (a), till the whole of the chromium is precipitated as
hydrated sesqnioxide. Crystals of pure chromate of potash may first be
obtained by evaporating the solution, and the impure mother-liquor after-
wards used for the preparation of the hydrated chromic oxide. (Trommsdorff,
iV. Tr, 18, 1, 225.) — <f. Berzelius adds a boiling solution of pentasulphide
of potassium to the boiling liquid (a), as long as chromic oxide is thrown
down. — In this process the sulphur is oxidized by half the oxygen con«
tained in the cnromic acid, and converted into sulphuric acid, which
combines with the potash. — e, Frick {Pogg, 13, 494) boils the liquid {a)
in a cast-iron pot till it is highly concentrated; then transfers it to glass
vessels and leaves it to settle; clarifies the concentrated solution by
decantation or filtration; boils it in an iron pot with sulphur till green
oxide of chromium ceases to be precipitated; collects tne oxide on a
filter and washes it; then dissolves it in warm dilute sulphuric acid;
filters from sulphur; precipitates chromic oxide from the filtrate by
carbonate of soaa; and lastly, frees it by ignition from water and carbonic
acid. If the washed precipitate is dissolved in hydrochloric acid instead
of sulphuric, and the filtrate evaporated to dryness and ignited in an
open vessel, an oxide is obtained of a peculiarly splendid green colour.
(Liebig.)— /. Lassaigne precipitates the earths from the liquid (a), by neu-
tralizing with sulphuric acid; evaporates the filtrate to dryness; ignites
the residue mixed with an equal weight of sulphur, in a covered crucible;
and exhausts the mass with water, which dissolves sulphate of potash and
sulphide of potassium, and leaves pure sesqnioxide of chromium.— A ccord«
ing to Moser, who uses only half the weight of sulphur, the oxide thus
110 CHROMIUM*
obtained is mixed with sulphiiT, which may, howeyer, he expelled by
repeated ignition in the air. — ^Wittstein {RepeH. QQ^ Q5) by igniting
for half an hour a mixture of 19 parts of bichromate of potash with
4 parts of sulphur, and washing the residual mass^ obtained 9-^ parts
of sesqnioxide of chromium, — •g, Berthier ignites chromate of potash in a
charcoal crucible, or mixes it with charcoal powder or lamp-black, and
Ignites it in an ordinary earthen crucible; dissolves the chromite of potash
produced, in cold water; heats the filtrate to the boiling point; collects
the precipitated hydrated oxide on a filter; washes it thoroughly with
water, and lastly ignites it. The supernatant liquid still contains a
portion of chromate of potash, besides carbonate, and, after evaporation
to dryness, may be used to decompose fresh portions of chrome-iron ore. —
h, Wohler {Pogg. 10, 46) ignites a mixture of bichromate of potash with
about its own weight of sal-ammoniac and a small quantity of carbonate
of soda, in a covered crucible, till no more vapour of sal-ammoniac is dis-
engaged, and then purifies the sesquioxide of chromium from chlorides of
potassium and sodium, by washing with water. IT t. Barian {Revue sc. d:
ind, 20, 425) mixes 4 parts of bichromate of potash with 1 part of
starch; ignites the mixture in a crucible, washes away the carbonate of
potash with water, and again ignites the residue. He states that the
chromic oxide thus obtained is so pure that it may be used for glazing
porcelain (provided of course the bichromate be pure in the first in-
stance). L Bottger (Ann, Pharm, 47, 339) gives the following method
(founded on observations of Unverdorben & W&hler), of obtaining chromic
oxide in the form of unrolled tea leaves. A quantity of crystallized chromic
acid, obtained by Warington's method (p. 1 17)^ is divided into two equal por-
tions, one portion of which is first neutralized with ammonia, the other then
added, and the solution evaporated over oil of vitriol. The bichromate of
ammonia crystallizes after a week or two in large cherry-red crystals,
which are dried at a gentle heat on bibulous paper. On exposing a small
quantity of the salt in a platinum dish, &c. to the flame of a spirit-Lump,
a very ener^tic action takes place, accompanied by strong incandescence,
and green bulky masses of chromic oxide shoot out in every direction,
very much resembling opened tea leaves. — I. According to the same
authority, the following method also may be employed. A very fine and
intimate mixture is made of 48 parts of gunpowder, 240 parts of perfectly
dry bichromate of potash, and 5 parts of equally dry chloride of ammo-
nium. This mixture is made into the shape of a cone (by pressing it
into a wine glass, and afterwards carefully shaking it out) and then trans-
ferred to an iron plate. A burning fusee or other combustible is then
applied to the top of the cone, whereupon it takes fire and burns
slowly throughout its whole mass. On exhausting the cone while still hot
with water, a residue of chromic oxide is obtained in the form of a pale
green powder. IF
II. From Red lead spar, (Chromate of lead.) — 1, The mineral is re-
duced to powder and boiled in a mixture of hydrochloric acid and alcohol;
the resulting sesquichloride of chromium filtered from the chloride of lead;
hydrated chromic oxide precipitated from the solution by ammonia, and
then washed and ignited. ( vauquelin.) — 2. When native chromate of
lead is boiled with a solution of carbonate of potash, the filtered liquid
contains chromate of potash mixed with oxide of lead; and from this
liquid the oxide of lead is easily separated as an insoluble chromate by
treating the solution with a small quantity of nitric acid. (Vauquelin.)
From the filtrate containing chromate and carbonate of potash, cnromic
ClIpOMIC OXIDE. . Ill
oxide may be prepared by any of the methods given under I, 1, a — g,
Berthier ignites the native chromate of lead in a charcoal crucible, and
frees tlie resulting chromic oxide from the metallic lead fused with it,
partly by means of a sieve, partly by dissolving out the lead with dilute
nitric acid.
III. To obtain crystallized chromic oxide, a few ounces of chromate of
terchloride of chromium are introduced into a small retort of very hard
glass, the neck of which is slightly inclined, and reaches, without touching,
nearly to the bottom of a fiask made of hessian clay, (or into a deep hessian
assay crucible, or a wide porcelain tube.) The earthen vessel is then
strongly ignited, and the retort heated till the chromate of terchloride of
chromium enters into gentle ebullition, and the whole is gradually vola-
tilized. Oxygen and chlorine are evolved and the sesquioxide is deposited
on the neck of the retort in crystals which are easily separated iu entire
crusts. (W5hler, Fogg, 3d, 341; also Ann. Fharm. 13, 40.) If oil or
sal-ammoniac is thrown upon bichromate of potash fused below a red
beat, in smaller quantity than that required for decomposing the salt, and
the mass heated to whiteness, allowed to cool slowly, and exhausted with
water, a mass of green chromic oxide remains, the cavities of which are
lined with small, shinine, green, and apparently rhombohedral crystals of
the same compound. (Ullgren, Jahreiher, 15, 141.) IT If dry chlorine
is passed over chromate of potash heated to redness in a porcelain tube,
the gas is completely absorbed, giving rise to chloride of potassium and
chromic oxide, which, under these circumstances, crystallizes in long
brilliant tables. The temperature has a ffreat influence upon the products ;
thus, at a dull red heat, green friable tables of chromic oxide are obtained;
at a strong red heat, on the contrary, brown, very hard crystals, of the
same form in other respects, but resembling W&hler's compound. The
crystallization of the chromic oxide is probably promoted by the presence
of the chloride of potassium, in the same manner as that of ferric oxide
is facilitated, when its sulphate is ignited with common salt. (E. Fr6my^
J. Fkarm. 1844, 105, abstr. Ann. Fharm, 49, 274.) IT
Froperiies, — 1. The crystallized chromic oxide obtained by method
III., belongs to the rhombohedral system of crystallization. Fig. 158,
r" : r* Fig. 151) = S5° 55^', cleavage distinct parallel to r; the crystals
are generally macled. (6. Rose.) Sp. gr. = 5 '21; scratches quartz, topaz,
and hyacinth. (Wohler.) Of the hardness of corundum. (G, Rose.)
Greenish black, with metallic lustre; the powder is also green. (Wohler.)
—2. Fulvertdent chromic oxide obtained by metiiods I. or II. a. A/ter
ignition: bright green, changing to brown every time it is ignited, b. Ob-
tained by decomposing the hydrate at a temperature below redness : dark
green. Sesquioxide of chromium fuses before the oxyhydrogen blowpipe,
and emits a white vapour, but is not reduced to the metallic state.
(Clarke.)
Calculation. Berzeliua.
2Cr 56 .... 70 ..-. 70-24
30 24 .... 30 .... 29 76
CrKfi 80 Z. ioiS Z 10000
(Ci*0> = 2 . 351-82-1-3 . 100 = 100*364. BerzeUos.)
Decompoaitians. — By charcoal^ but only at a most intense white heat;
by potassium and sodium at lower temperatures. Not by the oxyhydro-
114 CHROMIUM.
(Vauquelln, Brandenburg.) According to Maus, the nitric acid cannot
be completely driven off; inasmuch as, at the temperature required for
this purpose, the green oxide is produced. — 2. Green hyd rated chromic
oxide is heated to dryness with an aqueous solution of chromic acid. —
3. Hydrated chromic oxide is cautiously heated. — T 4. According to
Schweitzer (J, fur Pract, Chem. 39, 269), when a moderately dilute
solution of bichromate of potash is treated with nitric oxide, the gas is
absorbed in rather large quantity, the liquid assuming a dark colour, and
after some time depositing a brown precipitate. This substance has all
the properties of brown oxide of chromium. IT
Dark brown, somewhat shining powder (Vauqueliu): lemon-yellow
powder (Brandenburg).
At a temperature just below redness, it gives off oxygen gas, and is
converted into the ordinary ffreen oxide; when treated with hydrochloric
acid, it yields chlorine gas and green hydrochlorate of chromic oxide. (Ber-
zelius.) A warm solution of oxalic, tartaric, citric, or acetic acid, likewise
dissolves it in the state of green oxide, with separation of oxygen gaa.
(Brandenburg.)
H Kriiger maintains that this brown substance (at least as prepared
according to 3) is really a binoxide of chromium, and not a compound of
chromic oxide and chromic acid, because it yields only chlorine and no
chromate of sesquichloride of chromium, when heated with common salt
and sulphuric acid [or with hydrochloric acid?] vid, p. 115. IT
Combinations, — a. With water : Hydrated Brown Oxide of Chromium,
•— 1. Nitrate of chromic oxide is heated till the nitric acid is partially
decomposed. The mass is then dissolved in water, and the hydrate
precipitated from the brownish red solution by excess of ammonia.
(Vauquelin.) By this process, Moser obtained the hydrated green oxide,
but of a somewhat darker colour than nsual. — 2. Chlorine gas is passed
through the solution of a salt of chromic oxide while it is being precipi-
tated with potash. (Vauquelin.) This method did not succeed in Moser's
hands. — 3. Sulphurous acid is passed into an aqueous solution of chromic
acid; and from the resulting brown solution, the brown hydrate is preci-
pitated by ammonia. (Vauquelin.) — i. The hydrated brown oxide is
likewise precipitated by boiling a solution of chromate of ammonia.
(Vauquelin.) — 5. Through a mixture of the solutions of chromate and
carbonate of potash, a mixture of nitrons gas and atmospheric air (nitrous
acid vapour) is passed, and the hydrate is precipitated by heating the
mixture to the boiling point; if too much nitrous acid is used, nothing
but nitrate of the protoxide is formed. (Grouvelle.) — 6. A mixture of
chromate of potash, nitrate of ammonia, and carbonate of potash, is
evaporated to dryness, gently heated till the mass turns black, and then
digested in water : the portion of oxide which redissolves is afterwards
precipitated by ammonia. (Grouvelle.) — 7, The hydrated green oxide is
digested with an aqueous solution of chromic acid, the latter not being in
excess. (Maus.)— 8. Hydrochloric acid is thoroughly saturated with
?:reen oxide of chromium, and precipitated by monochromate of potash.
Maus.) — Bensch {Pogg, 55, 98) uses for this purpose a boiling solution of
snlphate of chromic oxide.
The hydrate, when moist, is reddish brown; when dry, it is black
(Vauquelin), or dirty yellow (Bensch).
b. With acids, forming the Salts of Broton Oxide of Chromium. The
strongly heated oxide is dissolved by acids with great difficulty; the
hydrate, readily, forming a brown solution. The solution reddens litmus.
BICHROMATE OF CHROMIC OXlDfi. 115
and is precipitated bj ammonia in large brown flakes; but if the ammonia
is in excess^ the brown oxide is resolved into green oxide and cLromic
acid, which combines with the ammonia. The solution does not precipi-
tate the salts of lead, mercury, or silver.
c. With the alkalis in solution, especially with potash.
The supposition of John and Dobereiner, that brown oxide of chromium
is not a distinct compound of chromium and oxygen^ but merely a very
feeble compound of the green oxide with chromic acid, is rendered highly
probable by the following experiments of Maus: When the hydrated
brown oxide is washed with cold water, the process must be continued
for three weeks before the wash-water (containing chromic oxide with
excess of chromic acid) ceases to affect a salt of lead; the washed residue
is^ then found to be converted into hydrated green oxide. Hot water acts
in the same manner, but much more rapidly. A solution of sal-ammoniac
or alcohol acts like water. — The hydrated brown oxide digested with
acetate of lead is converted into chromate of lead, while the supernatant
liquid contains acetate of the green oxide; a slight excess of acetic acid
accelerates the decomposition.— -By digestion with small quantities of
arsenic acid in solution, the brown hydrate is converted into insoluble
arseniate of green chromic oxide (which would dissolve were the arsenic
acid present in excess), and the solution contains pure chromic acid.
IT 2. Bichromate of Chromic Oxide.
CiaO", 2CrO» op Cr*0».
1. When chromic acid is' exposed on a glass plate, it dries up to a
brown crust which is insoluble in water, and adheres strongly to the
glass. This substance is bichromate of chromic oxide, produced by the
action of the dust in the air. It may also be prepared by treating a
moderately dilute solution of chromic acid with excess of alcohol at
ordinary temperatures, and heating the mixture after the evolution of
aldehyde has ceased: in a short time the reduction is complete. Part of
the compound sinks to the bottom of the vessel; part remains suspended
in the liquid, even after some weeks. The precipitate is boiled with
water till the smell of pure acetic acid is apparent, then agitated with
water, and lastly with absolute alcohol, till nothing more is dissolved out
by either liquid. The pure salt, when dry, presents the appearance of a
brittle, fissured mass, and yields a greenish-brown powder. Before
drying, it is readily soluble in hydrochloric and nitric acid, and with
greater difficulty in acetic acid. From these solutions chromic oxide is
precipitated by ammonia. Caustic potash easily dissolves it. (Traube.)— «
2. When a solution of chrome-alum is mixed with a solution of neutral
chromate of potash, the mixture first becomes brownish red, and sub-
sequently deposits a bright brown precipitate, the supernatant liquid
i having an intense yellow colour. The precipitate is washed with cold
V water till it passes through the filter colourless. This compound dissolves
in hydrochloric acid with a yellowish green, and in nitric acid with a
brown colour; the solution in both cases yields with ammonia a precipi-
tate of chromic oxide, leaving chromic acid in solution. Dilute sulphuric
acid slowly dissolves it at a boiling heat, forming a brown liquid. Solu-
tion of potash rapidly resolves it into chromic oxide and chromic acid;
ammonia does not affect it.
I2
116 CHROMIUM.
3. Neutral Chromate of Chromic Oxide,
CrSC, 3CrO».
This substance is formed, according to Traube, when chromic acid is
heated above 250°. Bj boilinff with water, or after remaining for a long
time in contact with that liquid, it is converted into a soluble modification
of the same salt, imparting to the water in the first ca«e a yellowish, and in
the second a deep brown colour. When it is heated with hydrochloric acid,
chlorine is evolyed, and a solution of sesquichloride of chromium obtained;
nitric acid diseolyes it very slowly. Dilute sulphuric acid slowly resolves
it into soluble sulphate of chromic oxide and chromic acid; concentrated
sulphuric acid, on the contrary, aided by heat, forms with it an insoluble
sulphate of chromic oxide and chromic acid. Potash decomposes it
readily; ammonia with difficulty, the action being apparently due to the
water contained in the ammonia. The salt contains 57 '93 per cent, of
chromium, and 42*07 of oxygen. (Traube.) IT
4. Soluble Brown Chromic Oxide or Add Chromate of Chromic Acid.
Ci«0» or Cr»0«, 4CrO».
|. A cold aqueous solution of chromic acid rapidly dissolves the
hydrate or carbonate of green chromic oxide. The solution has a darker
brown colour than pure chromic acid; is not rendered turbid by boiling;
and leaves^ on evaporation, a brittle homy mass, which is permanent in
the air, and dissolves without change in cold alcohol. It contains 27*79
per cent. (I atom) of the green oxide, and 72*21 per cent. (4 atoms)
of chromic acid. (Maus.) The solution gives a green precipitate with
ammonia; it may be repeatedly evaporated to dryness at a temperature
of 100°, without being decomposed; but if the evaporated mass is kept
at that temperature for a long time, it becomes insoluble. (Hayes.) On
mixing green sesquichloride of chromium with monochromate of potash,
a green solution is first obtained, which turns brown, and then deposits a
precipitate of the first compound; the liquid, however, still remains
brown. Possibly it contains the fourth compound = Cr*0', and the pre-
cipitate should be regarded as GrO'. (Berzelins.) [Probably then in this
manner: Cr*0»,3HCl4.3(KO,CrO») =3(KO,HCl)4.2(Cr»0»)+CrO»].
C. Chromic Acid. CrO*.
ChromBaure, Acide chromique.
Formaiion, — 1. By igniting chromic oxide with potash in an open
vessel, or with nitre, chlorate of potash (which rapidly disengages chlo-
rine gas), or peroxide of lead, the product being chromate of potash, or
chromate of lead. — 2, By treating the hydrated sesquioxide with an
aqueous solution of hypochlorous acid. (Balard.)
Preparation. — 1. A mixture of 1 part of chromate of lead, 1 part
of fluorspar, and 3 parts of fuming oil of vitriol, is gently heated in a
leaden vessel, over which a larger vessel of the same material, perforated
CHROMIC ACID. 117
with a great number of holes for the admission of air^ is inyerted* The
terflnonde of chromium ascending in vapour is decomposed by the mois-
ture of the air into volatile hydrofluoric acid and solid chromic acid,
which is prevented from falling into the lower vessel by a perforated
leaden plate laid on the mouth. (Unverdorben.) The further purifi-
cation recommended by Unverdorben, which consists in precipitating
with nitrate of silver and decomposing the chromate of silver by hy-
drochloric acid, will probably yield a chromic acid containing hydro-
chloric or nitric acid. A considerable quantity of chromium remains
behind in the leaden vessel, because the water in the oil of vitriol
prevents, to a certain extent, the formation of fluoride of chromium;
anhydrous sulphuric acid, or even fuming oil of vitriol, is not adapted to
the purpose, because the anhydrous acid volatilizes with the fluoride of
chromium. (Mans). — 2. A mixture of 4 parts of chromate of lead (or 8*2
parts of chromate of baryta), 3 parts of fluorspar free from silica, and 5 parts
of fuming sulphuric acid, or English oil of vitriol freed by boiling firom
excess of water, is gently heated m a leaden, or better in a platinum retort,
over an oil lamp; the vapour of fluoride of chromium thereby evolved is
passed into a platinum receiver containing water; and the hydrofluoric
acid and water expelled by evaporation (the addition of powdered quartz
is quite unnecessary) : the residue consists of chromic acid. (Berzelius.)— >
3. A hot solution of bichromate of potash is mixed with a quantity of
hvdrofluosilicio acid, not quite sufficient for precipitating the whole of
the potash; the solution filtered from the double fluoride of silicium and
potassium; the latter washed with water; the filtrate evaporated to a
small bulk in a porcelain basin; the remainder of the potash precipitated
by a slight excess of hydrofluosilicic acid; the liquid ' evaporated to dry-
ness in a platinum dish (a vessel of porcelain would be attacked by the
excess of hydrofluosilicic acid) ; the residue dissolved in the smallest
possible quantity of water; the aqueous solution of chromic acid decanted
(a filter would oe destroyed by so concentrated a solution) from double
fluoride of silicium and potassium; and lastly, evaporated to dryness.
(Maus.) — 4. A warm solution of bichromate ot potasn is carefully added
to an excess of oil of vitriol (any excess of the salt would crystaUia» out
without being deoomposed, and thus contaminate the chromic acid); the
liquid poured off from the chromic acid, which separates in small red
crystals; and the crystals drained in a funnel having its stem partly filled
with coarsely pounded glass. The chromic aoid is then placed under an
evaporating jar, on a brick which absorbs more of the sulphuric acid; and
lastly dissolved in a small quantity of boiling water. On cooling, the solu-
tion deposits crystals of nearly pure chromic acid. (Fritzsche.) Warington
{J, pr. Client, 27, 252) mixes 10 measures of a cold saturated solution of
bichromate of potash with from 12 to 15 measures of oil of vitriol, free
from lead, and presses the red acicular crystals, which separate as the
liquid cools, between porous stones. The chromic acid thus prepared con-
tains but a trace of sulphuric acid. % Bolley (Ann, Pharm. 56, 113) im-
proves upon this method by dissolving a weighea quantity of bichromate of
potash in a small quantity of boiling water, and adding to the hot solu-
tion the exact quantity of ordinary sulphuric acid required to convert the
potash into bisulphate. The mixture is then left to cool, whereupon
it solidifies for the most part in a red granular mass, consisting of bisul-
phate of potash with adhering chromic acid. The mixture is stirred to
separate the insoluble grains, and the solution decanted from the bisul-
phate of potash, which is washed several times with cold water to remove
I
1 1 8 CHROMIUM.
the whole of the chromic acid.* The solution of chromic acid containing
a small quantity of bisulphate of potash is then further concentrated,
and the chromic acid precipitated hj about an equal volume of sulphuric
acid, which throws it down free from all traces of bisulphate of potash.
It is then drained in a glass funnel, loosely closed with pieces of glass,
and finally obtained in perfectly pure and large crystab by repeated
solution in water, and recrystallization by slow evaporation. — Traube
(Ann. Fharm, 66, 170) heats 1 part of bichromate of potash with 3^
parts of sulphuric acid and 2^ parts of water, and adds 4 parts of
sulphuric acid to the solution of chromic acid decanted from the crys-
tallized bisulphate of potash. The' chromic acid Is precipitated in red
flakes, which are redissolved in a small quantity of water, and the solu-
tion evaporated to the crystallizing point. The acid thus obtained may
be purified from chromate of potash either by re-solution in water and
precipitation by sulphuric acid, &c., or by careful fusion in an air-bath,
whereby insoluble double sulphate of chromic oxide and potash, and
insoluble sulphate of chromic oxide are obtained by the mutual action
of the several elements present The chromic acid is afterwards sepa-
rated by exhausting with cold water, and crystallized by evaporation
in the ordinary way. IT — 5. Chromate of baryta is digested with a quan-
tity of dilute sulphuric acid, not suflicient for complete saturation, and
the baryta precipitated from the filtrate— which contains chromic acid
and acid chromate of baryta — ^by the exact amount of sulphuric acid
required, so that the solution is neither afifected by sulphuric acid nor by
a Bali of baryta; it is then filtered and evaporated to dryness. 1[Meiss-
ner.) — Dobereiner decomposes chromate of baryta with a slight excess
of sulphuric acid, and afterwards removes the excess of sulphuric acid
from the filtrate by the addition of an equivalent quantity of baryta-
water.
Fropertie8.'-^A6 prepared by the first method, chromic acid forms a de-
licate, woolly, scarlet-coloured, asbestos-like mass, so light that a cubic
inch weighs only 0*2 of a gramme. (Unverdorben.) Prepared by the second
method^ it forms a solid, dark red mass, which turns black when heated.
(Berzellus.) From a concentrated solution, it crystallizes in carmine-
coloured needles, or in large brownish red crystals which yield a carmine-
coloured powder. (Fritzsche.) It fuses when heated [to 180° or 190®
Trauhe], forming a bright reddish brown liquid, which, on coo1in<i^^ soli-
difies in a red, opaque, and brittle mass. (Unverdorben.) Chromic acid is
inodorous; tastes very acid at first, and afterwards rough, but not
metallic; it imparts to the skin a yellow stain, which is not removed by
water but yields to an alkali. (Unverdorben, Berzelius.)
Cr
30
Calcolatioi]
28
24
1.
53*85
46-15
• • •
Berzeliiis.
5413
45-87
CrO»....
52
...
• • .
76-9
231
100-00
• V ■
• ••
Godon.
741
25-9
100-00
Or:
Ci»0»
30...
80
24
Vtnqaelin.
... OO'o
14-2
2CrO».
104
...
100-0
. ••
1000
... 1000
(CrOS» 351*82 + 3 • 100 — 651*82. rerzelios.)
SALTS OF CHROMIC ACID. 119
Decompositions, — When lieated above the melting point [above 250°,
Traube]j it is resolved into oxygen gas and sesquioxide of chrominm
[nentral chromate of chromic oxide, Travhe], and if the acid has been
prepared hj the first method, the resulting oxide exhibits incandescence.
(Unverdorben, Berzelius.) By heating the acid with oil of vitriol, oxy-
gen gas and sulphate of chromic oxide, are obtained. — 2. If chromic acid,
prepared by the second method, be introduced at ordinary temperatures
into ammoniacal gas, it instantly becomes white hot, and is reduced
into chromic oxide. (Unverdorben, Bottger, Ann. Fharm, 57, 134.) —
3. Heated potassium or sodium reduces chromic acid with incandescence —
probably to the metallic state. (Gay-Lussac & Thenard.) — 4. Phosphorus
dissolves in an aqueous solution of chromic acid, producing green phos-
phate of chromic oxide. (Jacobson.)— 5. When hydrosulphuno acid gas
16 passed over the dry heated acid, decomposition takes place, attended
with vivid incandescence, the products being sulphur, water, and sesqui-
eulphide of chromium. (Harten, Ann. Fharm, 37, 350.)
2CrO»+6HS = Ci«S> + 6HO + 3S.
The aqueous acid is decomposed by sulphuretted hydrogen into water,
sulphur, and chromic oxide. — 6. Sulphurous acid converts aqueous
chromic acid into sulphate of chromic oxide.
2CrO»+3SO» = Cr203,3SO».
With ^ smaller quantity of sulphurous acid, the brown oxide of chromium
is produced. IT Dry chromic acid is not affected by sulphurous acid at
100°; at 1 80"^ that acid converts it into chromate of chromic oxide, with
evolution of anhydrous sulphuric acid. (Traube, Ann. Fharm, 66, 103.) —
7. Hydriodic acid and boiling hydrochloric acid form green solutions of
sesqu iodide or sesquichloride of chromium, with evolution of iodine or
chlorine. — 8. Chromic acid in solution is likewise reduced to the state
of chromic oxide by nitric oxide, by arsenious acid, and by agitation
with mercury. — 9. Many organic substances, as citric acid, tartaric acid,
alcohol, and paper, convert chromic acid, especially when aided by light,
or heat, into green or brown oxide, carbonic acid being formed at the
same time. The concentrated acid corrodes paper like oil of vitriol, the
action being attended with formation of brown oxide of chromium.
(Mans.) The dilute acid assumes a green colour when exposed to
light. Vegetable substances saturated with aqueous chromic acid and
then dried, burn with a vivid and continuous flame. (Jacobson.)
»
ComMnatums, — a. With Water. — Aqueous Chromic Acid. — Chromic
acid rapidly deliquesces in the air, and dissolves very easily in water,
forming a dark reddish brown, or, with more water, a lemon -yellow solu-
tion. Chromic acid imparts a yellow colour to very large quantities of
water.
h. With Salifiable Bases, chromic acid forms salts called Chrohates.
Most of them are either bibasic, monobasic, or biacid salts. The normal
chromates of the alkalis and earths are yellow; the alkaline bichromates,
aurora-red; the chromates of the heavy metals are bright yellow, red, or
occasionally of some other colour. The alkaline monochromates remain
nndecomposed even at a full red heat, unless carbon is present, in which
case the chromic acid is reduced to chromic oxide; chromates containing
a weaker base give ofiLoxygen gas when heated alone, and form chro-
mic oxide. Before the blowpipe, the chromates impart a green colour
to borax and microcosmic salt. When heated with oil of vitriol; they
120 CHROMIUM.
all eyolre oxygen g&B, aud yield sulphate of chromic oxide, together
with another eulphate. The anhydrous salts, heated with hydrochloric
acid, evolve chlorine gas, and form sesquichloride of chromium and
another metallic chloride. Heated in the anhydrous state with common
salt and oil of vitriol, they give off red vapours of chlorochromic acid,
which condenses to a brownish red liquid. Similarly, when heated with
fluorspar and oil of vitriol, they evolve red vapours of terfluoride of
chromium. A few only of the chromates, more particularly those of
the alkalis, are soluble in water, but they all dissolve in nitric acid.
^ Kopp has obtained many of the heavy metallic chromates in a hydrated
and even soluble form, by digesting the corresponding metallic sulphate
with chromate of baryta for a considerable time, or more rapidly by
treating the oxide or carbonate with a dilute solution of chromic acid.
The salts thus obtained are precisely analogous to the corresponding sul-
phates (vid. chromate of copper and chromate of zinc). T The aqueous
yellow solutions (reddish yellow, if they contain excess of chromic acid)
assume a deeper colour on the addition of sulphuric, nitric, or hydro-
chloric acid, in consequence of the separation of chromic acid. When
hydrochloric acid is used, chlorine is evolved, and the red colour changes
to the green of sesquichloride of chromium, gradually at ordinary tem-
peratures, more quickly on boiling, and still more quickly on the addi-
tion of alcohol. When the solution of a chromate is mixed with sulphuric
or acetic acid, and a current of hydrosulphuric acid gas passed through
it, sulphur is deposited and the liquid assumes a green colour from forma-
tion of sulphate or acetate of chromic oxide. According to H. Rose, the
whole of the sulphur in the hydrosulphuric acid is precipitated in the free
state, but if the gas is passed through a hot mixture of a chromate with
acetic acid, decomposition is more rapidly effected, and the greater part
of the sulphur is converted into sulphuric acid. Sulphurous acid rapidly
converts chromic acid in the soluble salts into sulphate of chromic oxide.
Zinc decomposes the alkaline monochromates and bichromates, when dis-
solved in water and mixed with sulphuric acid, forming a green solu-
tion of chromic sulphate. Mercury, according to Jacobson (J, pr. Chem.
23, 467), quickly produces in solutions of the alkaline bichromates,
and more slowly in solutions of the monochromates, a precipitate of
hydrated chromic oxide. Oxalic, tartaric, or citric acid (but not acetic
acid), converts the soluble chromates, especially when heated, into green
solutions of chromic oxide, with evolution of carbonic acid. Alcohol and
sugar act in a similar manner, on the addition of a small quantity of sul-
phurio acid. The alkaline chromates, dissolved in water, precipitate
baryta salts pale yellow, lead and bismuth salts bright yellow, mercurous
saltfl brick red, and silver salto purple red ; these precipitates are all
soluble in nitric acid.
c. With several metallic chlorides, which play the part of a basic
metallic oxide.
d. Chromic acid is soluble in alcohol and ^ther.
D. Pbbchromio Acid. Cr*0^
UAerckromsSure, Acide mrchromiqne.
When peroxide of hydrogen, dissolved in water, is mixed with a
eolation of chromic acid, the liquid assumes a deep indigo-blue colour;
Vat it often loses this colour very rapidly, the liquid evolving oxygen gas,
CARBONAT£ OF CHROMOUS OXIDE. 121
The same blue coloar is likewise prodaced on adding amixtare of aqueoas
peroxide of hydrogen and sulphario aoid^ or hydrochloric acid, to bichro-
mate of potash; bat in a yery short time oxygen gas is disengaged and a
potash salt together with a chromic salt, is left in the solution. In this
case, for each atom of bichromate of potash, 4 atoms of oxygen gas are
eyolyed; provided an excess of peroxide of hydrogen is present:
KO, 2CrO» + O + 4S0» = KO, S0» + Cr»Os, 3S0" + 40-
Consequently, the peroxide of hydrogen must first have ffiyen up one
atom of to the two atoms of CrO' and formed Cr'O'', this compound
being subseauently resolved, with evolution of four atoms of 0, into
Cr'O'. With ether, the acid forms a more stable blue mixture than with
water. To prepare this compound, according to Th6nard's directions
(p. 74), peroxide of barium is dissolved in hydrochloric acid; the liquid
covered with a stratum of ether; a solution of bichromate of potash care-
fully added, and the whole agitated together: the lower aqueous stratum
then appears colourless, and the blue ethereal solution is poured off.
When the liquid is left to evaporate in the air, the whole of the ether
escapes, but the blue coloar suddenly disappears, with evolution of
oxygen gas, and chromic acid alone remains. Alkalis instantly decom-
pose perchromic acid, disengaging oxygen gas and forming an alkaline
chromate. Perchromic acid, however, dissolved in ether, may be made
to unite with ammonia and certain organic bases, producing very stable
compounds, from which stronger acids separate the blue acid. (Barreswil,
Compt. rend. 16, 1085; also J. pr. Chem, 29, 296; also ImtU. 1846^ 320.)
Ghromiitm and Carbon.
IT Carbonate of Chromous Oxide. — The precipitate produced in a
0olation of protochloride of chromium by alkaline carbonates resembles in
many respects the carbonates of magnesia, sine, and ferrous oxide.—-
1. When the protochloride is added to a boiling solution of carbonate of
potash, a red or reddish brown precipitate is formed, which, when the
ebullition ceases, sradually acquires a bluish green colour (provided air
be excluded), while the supernatant liquid becomes yellow and deposits
brilliant, brownish yellow, lamellated crystals. These, when exposed to
the air on bibulous paper, become opaque and green, but retain their
brilliancy. If again put into water they turn yellow, and yield a yel-
lowish solution, together with a greenish blue residue.— * 2. If a cold
boiled solution of carbonate of potash is used, the precipitate is some-
times obtained in the form of a dense yellow powder, sometimes in the
form of bluish green flakes, which appear however to have the same con-
stitution as the powder, inasmuch as, on dissolvine the former in a fresh
quantity of water, the floooulent precipitate is found to increase on stand-
ing. — If the yeUow or brownish red solution is exposed to the air, it
turns green, and at the same time a green substance separates, which is
immediately precipitated on the addition of alcohol. Wnen the liquid is
kept in close vessels, it evolves carbonic acid, becomes turbid, and depo«
sits the greenish, flocculent precipitate mentioned above: this likewise
disengages carbonic acid and hydrogen gas, turns brown, and appears to
be transformed into Peligot's hydrated chromoso-chromic oxide. The
precipitate obtained from the eold potash solution does not change on
polling, excepting that it gives off carbonic acid; and afterwards dissolves in
123 CHROMIUM.
acids witbout efferyescence. Bicaibonato of potash behaves like the
simple sali^ but evolves a larger quantity of carbonic acid^ and retains
more of the chromous carbonate in solution. (Moberg.) ^
Carbonate of Chromic Oxide. — Prepared by precipitating a salt
of chromic oxide with a moderate excess of carbonate of ammonia^
potash, or soda. Light pale greenish blue powder. According to Meiss-
ner, it contains 7730 per cent, of oxide, 15-54 of acid, and 7-16 of water.
The carbonic acid is evolved at a temperature of 62®, TMeissner.) ^ The
salt is insoluble in water, but when recently precipitated, dissolves in an
aqueous solution of carbonate of potash. IT According to Lefort, it
consists of Cr*0',C0'-|-4H0, and loses 3 atoms of water between 75*
and 150^; but the last atom of water and the carbonic acid are not
evolved till the temperature exceeds 300°. (fiompt rend, 27, 269.) IT
Chromium and Boron,
IT Borate of Chromous Oxide. — Obtained by precipitating the
protochloride with borax. Pale blue precipitate soluble in free acids, but
insoluble in excess of the reagent. (Moberg.) IT
Borate of Chromic Oxide.-— a. Borate of ammonia precipitates
from a solution of sesquichloride of chromium, even when largely diluted,
a pale green powder, insolublo in water. (Hayes.) Borax produces a
blue precipitate soluble in excess of the reagent. (Berlin.)---^. Sexbo-
rate of potash gives a green precipitate with chromic salts. (Laurent.)
Chromium and Phosphorus.
A. Diphosphide of Chromium.*—!. Formed when phosphuretted
hydrogen gas is passed over heated sesquichloride of chromium.
CiaCl» + PH» = CrP + 3Ha.
The resulting phosphide of chromium retains the crystalline scaly form
of the chloride of chromium used. It is black; fives a phosphorescent
flame before the blowpipe; does not dissolve in hydrochloric acid, and, to
a ver^ small extent and only after long boiling, in nitric or nitrohydro*
chloric acid. (H. Rose, Pogg. 24, 333.) — 2. Phosphate of chromic oxide
is pressed down into a charcoal crucible and heated in a blast-furnace.—
The product is a slightly coherent, light grey, somewhat brilliant mass,
which conducts electricity, undergoes but slight change in an open fire, and
is oxidized with difficulty in the outer blowpipe flame. It is decomposed
b^ hydrate of potash at a red heat only, a gas being evolved which bums
with a yellow name, and without any odour of phosphorus; after a long
interval, the yellow colour of chromate of potash appears. It scarcely
imparts any colour to boiling aqua-regia, even after digestion with it for
many hours; it is insoluble in all other acids^ even the hydrofluoric.
(Berzelius.)
Calculaticni. H. Rose.
2Cr 56-0 .... 64-07 64-5
P 31-4 .... 85*93 35-5
WP Wl Z lOOOQ Z!I 100-0
SULPHIDE OF CHROMIUM. 123
B. PHOSPHiTfi OF Chromic Oxide. — An aqneons eolation of sesqui-
chloride of chromium is precipitated hj terchloride of phosphorus dissolved
in water and neutralized with ammonia. The phosphite of chromic
oxide remains partially dissolved, imparting a green colour to the liquid;
it likewise redissolves in the wash-water; hut on heating these solutions,
it is perfectly precipitated, leaving the supernatant liquid colourless.
Loose, green powder, which, when ignited in a retort, evolves hydrogen
gas free from phosphorus and without any appearance of light. (H. Rose,
Pogg. 9, 40.)
IT C. Phosphate of Chromous Oxide. — Phosphate of soda produces
in a solution of the protochloride an abundant blue precipitate, which is
readily dissolved by acids, and rapidly turns green on exposure to the air.
(Moberg.) IT
D. Phosphate of Chromic Oxide.-^^. Nenaral PhonpkaU. On
mixing sesquichloride of chromium with phosphate of potash, a green
precipitate is obtained, which appears bluish black after ignition, but
yields a greenish brown powder.
h. Acid Phosphate, — Hydrated sesquioxide of chromium yields with
aqueous phosphoric acid an emerald-green, uncrystallizable solution.
(Yauquelin.)
T E. Ptrophosphate of Chromio Oxide. — ^Formed by precipitating a
solution of crystallized chrome-alum with pyrophosphate of soda. At ordi-
nary temperatures, a dirty red precipitate appears; but with a boiling solu-
tion, a pale green precipitate is obtained. This salt is soluble in solution of
pyrophosphate of soda; in strong mineral acids; in water acidulated with
sulphuric acid, from which it is again precipitated in an amorphous state
on boiling; and in solution of potash. At 100^, it assumes a deeper green
colour, but after ignition appears paler. The hydrate contains 7 atoms of
water. (Schwarzenberg, Ann, Pharm, 65, 2.)
2Ci«0»
3P0*...
Calculation.
Schwarzenberg.
1600 .... 42-76
41-46
214-2 .... 57-24
58-54
2Ci«0»,3P0» 374-2 .... 100-00 100-00
F. Metaphosphatb of Chromio Oxide. — Prepared by Maddrell
(Mem, of Chem, Soc, 3, 273) by dissolving chromic oxide in excess of
dilute phosphoric acid, and heating the dry mass to 316°. Beautiful
green, anhydrous salt, insoluble in water and concentrated acids. IT
Calculation. Maddrell.
Ci«0» 80-0 .... 27-269 27-164
SPCy 214-2 .... 72-731 72 836
Ci«0», SPG" 294-2 Z 100000 ~., lOO'OOO
Chbomivh and Sulphur.
A. Sulphide of Chromium. IT — 1. Proiosulphide. — By igniting the
red sulphate of chromic oxide in a current of hydrogen gas, Traube
^^btained a highly pyrophoric mixture of proiomlpnide of chromium (ind
124 CHROMIUM.
chromic oxide = CrS+Cr'O'. He does not, howerer, appear to have
separated the protosulphide, or to have studied many of its properties. —
2. Protochloride of chromium gives a black precipitate with sulphide of
ammonium. (Moberg.) IT
b, SesquUuXphide. — 1. Formed by passing the vapour of bisulphide of
carbon over chromic oxide heated, to whiteuess in a porcelain tube.
(H. Rose.)— 2. Bj passing hjdrosulphuric acid eas over strongly ignited
sesquichloride of chromium [or the red sulphate of chromic oxide, Travhe\.
(Liebig, Harten, Ann* Fharm, 37^ 349.)
Cr«Cl» + SHS « Cr«S> + 3HCI.
3. By heating an intimate mixture of hydrated chromic oxide and sulphur
in a close yessel. (Berzelius.) — 4. By fusing chromic oxide with penta^
sulphide of potassium at a very high temperature, and dissolving out the
sulphide of potassium by water. (Berzelius.) Chromic oxide may also
be fused with sulphur and carbonate of potash. (Fellenberg, Fogg, 50, 77.)
— 5. By heating sesquichloride of chromium and 5 parts of sulphur to
redness in a retort. (Lassaigne.) In this ciusei according to BerzeIiuS| the
decomposition is not complete.
Sesquisulphide of chromium, as prepared by the second method, is
black, and sometimes of a crystalline shining texture (Liebig); sometimes
pulverulent. ^Harten.) As prepared by the third method, it is dark
grey, and yielas a black powder, which, when pressed, becomes coherent,
and assumes the metallic lustre. (Berzelius.^ The fourth method yields
green shining scales, like pounded graphite (Berzelius), soft and unctuous
to the touch. (Felienberg.) By the fifth method, an iron-black, unctuous,
very light mass is obtained, which readily imparts a stain. (Lassaigne.)
Calculation.
2Cr 56 .... 58*84
3S 48 .... 46-16
Ci»SS 104 .... 100-00 1000 Z 94-72 100-00
Sesquisulphide of chromium, when heated to redness in the air, bums
like a p3rrophorus, yielding sulphurous acid gas and a residue of sesqui-
oxide. (Lassaigne.) At a red heat, it decomposes aqueous vapour, forming
hydrosulphuric acid and a small quantity of green sesquioxide. (Regnault,
Ann. Chim. Phys, 62, 881.) It is partially decomposed by chlorine at
ordinary temperatures, but perfectly with the aid of heat, sesquichloride
of chromium being sublimed. (Berzelius, Felienberg, Harten.) Chlorine
scarcely acts on it, even at high temperatures. (H. Rose, Pogg, 42, 541 .)
By aqua-regia it is converted into sesquichloride of chromium and sul-
phuric acid (Lassaigne); by nitric acid, according to Berzelius, it is
decomposed with difficulty; according to Lassaigne, no decomposition
takes place, even when the acid is boiled with it. When ignited with
nitre, it yields sulphate and chromate of potash. (Lassaigne.) It is not
dissolved by potash, or by hydrosulphate of potash. (Berzelius.)
c. Tersvlphide of Chromium f [Vid. Termlphide of Chromium with
Hydrosulphate ofAmm>onia, and Termlphide of Chromium with Sulphide
of Potassium.]
IT B. Sulphite op CnROMous Oxide. — Obtained from the proto-
chloride by double decomposition. Brick-red precipitate, which, when
washed out of contact of air, becomes chestnut-orown after some days.
FeUenberg, 4.
Harten^ 2. Laaaaigne, 5
OJ'u ....
5102 .... 90-46
46-5
43-70 .... 9-54
SULPHATE OF CHROMIC OXIDE. 125
and gradually assnmes a hlmah green colour^ prooeeding from the surface
inwards. In the air, these changes take place very rapidly, in conse-
qiience of the conversion of the salt into hasio sulphite of chromic oxide.
(Aioberg.) IT
C. SuLPRiTB OF Chromic Oxide. — ^An aeneous solution of sulphur-
ous acid readily dissolves the hydrated sesquioxide. (Vauquelin.) The
green solution deposits, on boiling, [or on the addition of alcohol,] the
whole of the oxide, as a green, granular, basic salt [a whitish green
powder, which has a sulphurous taste, and gives off sulphurous acid when
neated : AluspraU], Neither ammonia nor carbonate of potash or soda
precipitates a cola solution of the salt; but from a hot solution, these
reagents throw down the whole of the chromium: the cold solution,
mixed with ammonia, has a pale wine-red colour. The alkaline
sulphites do not precipitate the chromic salts, even after long boiling.
(Berthier, Ann, Chim, Phyg. 50, 370; N, Ann, Chim, Phys. 7, 77.)
According to Berlin^ sulphite of potash precipitates the hydrochlorate of
chromic oxide.
D. Hyposulphatb OF Chromic Oxide.— Cr*0',S*0*.—^mall violet-
coloured octohedrons, soluble in water. (Berlin.)
1 E. Sulphate of Chromous Oxn>B.-*-Peligot (N, Ann. Chim.
Phys. 12, 548) states that on treating the metallic powder reduced from
the violet sesquichloride of chromium by potassium, with dilute sulphuric
acid, hydrogen gas is disengaged, and a solution obtained which exhibits
the characters of a chromous salt. IT
P. Sulphate op Chromic Oxide. — a. Two-thirds Sulphate. — Preci-
Eitated on mixing a concentrated solution of b with water, and also on
eating the restdting clear supernatant liquid. In the hydrated state, it
forms a light-green, very hygroscopic powder, which, when heated, first
loses the whole of its water, without fusing, and then, at a low red heat,
gives off all its sulphuric acid, leaving chromic oxide of a rather dark
ereen colour. It gives up the whole of its sulphuric acid when digested
for some time with caustic potash or carbonate of potash. It is insoluble
in water, but dissolves in acids, though with greater difficulty in propor-
tion as it has been more quickly dried. (Schrbtter, Po^g. 53, 513.) Vau-
quelin likewise obtained an insoluble basic salt by strongly heating tbe
salt b. From a solution of potash chrome-alum, caustic ammonia or car-
bonate of ammonia precipitates a greyish-red basic salt, which appears
pale blue after drying, and dissolves slowly but perfectly in acids, forming
a violet solution. (Berzelius.)
Anhpdrou$. Hydrated. Schrotter.
3Ci«0» 240 .... 75 SCr*0». 240 .... 63-81 .... 5302
2S0« 80 .... 25 2S0» 80 .... 17-94 .... 18-29
14HO 126 .... 28-25 .... 2821
3Ci30*,2SO> 320 .... 100 +14Aq 446 .... 10000 .... 9952
b. BitvJphate. — Dilute sulphuric acid is saturated with hydrated
chromic oxide by long boiling and concentration. Tbe dark green
solution, which is acid to test-paper, leaves on drying a green amorphous
mass, from which the whole of the sulphuric acid is expelled by ignition.
The eolation exhibits a dark ruby colour by transmitted suu-light or candle-
126 CHROMIUM.
light. (Schrbtter.) If tbe aboye Bolution, which appears green hy Jay
and red by candle-light, be introduced into a hollow prism whose
refracting angle is between 5° and 10°, and the prism be then placed
between the eye and a candle, two images of the candle appear, one red
and the other green; the rest of the spectrum is absorbed; so that a kind
of double refraction is produced. If the solution is placed in a bottle,
and looked through, the two images overlap each other, the^reen predo-
minating by da^ght, the red by candle-light. (Talbot, if! Br, Arch.
5, 141.)
A concentrated solution of bisulphate of chromic oxide is rendered
turbid by the addition of water, depositing a larger quantity of the salt a,
and becoming paler coloured in proportion to the amount of water added;
on evaporation, however, the precipitate is redissolved. The dilute solu-
tion filtered from the precipitate, deposits when heated a fresh quanti^
of the salt a, which again disappears on boiling. A solution of specims
gravity 1*219 and above, deposits nothing when heated; a solution of
1166 becomes turbid at 57^ of 1-037 to 1031, at 64^; of 1-002, at 45°;
and of 1*001, at 55°; a still more dilute solution remains clear even at a
boiling heat. (Schrdtter.)
Anhydroui. Schrotter.
Ci*0» 80 .... 50 60-44
2SO» 80 .... 50 49-56
Cr«0»,2S0» 160 .... 100 100-00
c. TerBulphaie, — a. InsoluhU. — If a green pasty mixture of the salt b
with oil of vitriol, is heated till the sulphuric acid begins to volatilise, it
immediately assumes a pale peach-blossom colour. With a large quantity
of oil of vitriol, a green limpid mixture is obtained, which, when heated,
becomes colourless, and deposits a peach-blossom coloured powder. The
red salt, which, after cooling, appears pale reddish grey, is purified with
water and then dried. It exhibits a very light red tint in diffused daylight;
very pale green in the direct rays of the sun; and verdigris-green by candle*
light. Every time it is heated, it assumes a beautiful peach-blossom colour.
When long ignited over the flame of a spirit-lamp, it loses the whole of
its sulphuric acid. Ignited in a current of hydrogen gas, it yields water,
hydrosulphuric acid, sulphur, and sesquioxide of chromium. It is readily
decomposed by fused or boiling caustic potash or soda, and slowly and
imperfectly by a boiling solution of carbonate of potash. It remains
unchanged in ammonia, and is insoluble in water, sulphuric, hydrochloric,
nitric, or nitro-hydrochloric acid. (Schrotter.)
IT Traube states that this salt is really an acid salt of chromic oxide,
and that it is probably formed when any salt of chromic oxide is heated
with strong sulphuric acid, he himself having prepared it from the
hydrated oxide, from chrome-alum, and from chromate of potash (the
bichromate yields a compound of the same salt with sulphate of potash,
the proportions varying according to the temperature). Accoraing to
Traube, also, it is grey by daylight, and green by candle-li^ht, and forms
sometimes a granular, sometimes a soft powder, so fine indeed that it
passes through the filter. In the finely divided state it likewise remains
suspended in water for a considerable time, but may be rapidly thrown
down by the addition of various salts, as sal-ammoniac, &c. It is inso«
luble in cold water, but by long boiling or by long standing in contact
with water, it is partially converted into a soluble modification. It is
likewise insoluble in ammonia and the strong mineral acids. It is decom-
SULPHATE' OF CHROMIC OXIDE. 12?
posed by ignition in a current of hydrogen gas, the volatile products being
water, snlphur, sulpharons acid, and lastly^ hydrosulphuric acid — the
residue, a black, pyrophoric mixture of protosulphide of chromium and
chromic oxide. A current of hydrosulphuric acid gas' at a high tempera*
ture converts it into black sesquisulphide of chromium, with disengage*
ment of sulphur, sulphurous acid, and water. Its formula is 2(Cr*0',3S0')
H-HO,SO*. IT
CraQS
Dried at lOO*'
80 .... 40
120 .... 60
Schrotter.
40-08
3SO»
59-40
Ci^O», 3SO» ..
2CraO»
7SO»
HO
200 .... 100
According to Traube,
160 .... 35*63
280 .... 62-36
9 .... 201
99-48
3413
62-90
3-18
KO
012
2(CrSO»,3SO») +
HO, S0> ....
449
.... 100-00
100-33
ff, SolvhUform, — 1. Greeii, amorphous modification. Eight parts of
hydrated chromic oxide dried at 100*^, are dissolved in 9 ports or rather
more of warm oil of vitriol. The light of a candle transmitted through
the green solution of this salt is ruby-coloured, and the solution does not
yield crystals on evaporation or on the addition of alcohol. Evaporated at
a temperature above 100°, it leaves a green, tenacious mass, containing
either 5 or 6 atoms of intimately combined water, which is expelled
when the substance is heated to the boiling point of linseed oil; at that
temperature, the salt is converted into the insoluble peach-blossom
coloured salt a. (Schr'otter.)
2. Blue^ crystalline modification. — 1. A solution of 8 parts of hydrated
chromic oxide in 9 parts of cold sulphuric acid left to itself in a covered
basin, solidifies in the course of a few weeks to a greenish blue crystalline
mass. This forms with water a dark blue solution, which euiibits a
beautiful ruby-colour by transmitted candle-light. Alcohol precipitates
from it a pale violet-coloured, crystalline powder, and decolorizes the
liquid. It is only when there is an excess of acid (which is better) or a
deficiency, that the solution remains green. To obtain good crystals, the
crystalline powder is collected on a filtei^— dissolved in a moderate quan-
tity of water— dilute alcohol added nearly to the point at which a precipi-
tate appears — and the solution left to evaporate spontaneously in a vessel
covered with a bladder.
IT 2. Traube prepares this compound by dissolving 1 part of purified
chromic acid in 3 parts of water, and sunerinff alcohol to drop into the
mixture from a funnel stopped up with paper. As soon as the reduction of
the chromic acid is complete, absolute ucohol is added — whereby the blue
compound is immediately precipitated — and the precipitate washed with
alcohol. Should the temperature rise in the first mstance from incautious
addition of alcohol, and the green modification be thereby produced, the
solution must be boiled with nitric acid — ^which (accoraing to Lbwel)
rapidly converts the green into the violet compound — and wen precipi-
tated by alcohol. — 3. It may also be obtained by dissolving 1 part of
chromic acid in l^ parts of strong sulphuric acid and 2^ parts of water,
and pouring the mixture into a wide basin in which a porcelain crucible
containing ether is placed^ The whole mass solidifies after some hours.
128 CHROMIUM.
forming small cnrBiais of chromic sulphate. To complete the redactiou,
a few drops of alcohol are finally added. IT
The salt crystallizes in regular octohedrons, of the colour of chrome-
alnm^ and of specific gravity 1'696; soluble in 0*833 parts of water at 20^
At a temperature of 100°, the crystals lose 10 [or 9 ?J atoms of water, and
pass into the green amorphous modification— and then, if heated above the
boiling point of linseed-oil, into the red, insoluble modifioation », An
aqueous solution of the crystals becomes green at a temperature of
Q5° or 70", from formation of the green, amorphous modification. IT By
adding strong alcohol to this solution, a green syrup is precipitated,
which, by shaking, or after some hours' standing, partly solidifies, yielding
crystals of the blue salt. If, however, the violet solution be boiled for a
long time, and then treated with strong alcohol, a green syrup is precipi-
tated, which remains fluid even after several days. The blue salt may be
boiled with alcohol (with a boiling point of 80°) without conversion into
the green modification. (Traube.) IT
If the blue solution of the salt, not very highly concentrated, be
placed in a narrow glass tube, and a deep stratum of absolute alcohol
carefully poured on the top of it, so as to prevent precipitation, the solu-
tion gradually assumes a green colour, proceeding from the top down-
wards« doubUess because the alcohol removes from the blue salt a portion
of the water necessary to its constitution. (Schrbtter.)
Ci^O» ,...,.
GyitaUiMed and dried at 30°
,„., 80 ...« 23*88
Sohrotter.
24*415
3SO»
15H0
120 .... 35-82
135 .... 40-30
35-472
40-113
Ci»0»,3SO»+15-
\q 335 .... 100-00
. 100*000
O. Browh Sulphate of Chromic Oxn)B.-^Brown oxide of chromium
yields, with sulphuric acid, a dark brown solution, which becomes green
when exposed to light. (Berzelius.) If the solution is saturated with oxide,
it leaves on evaporation, a yellowish brown mass, which, after exposure to
light for a few hours, is converted into the ordinary green sulphate. If
the sulphurie acid is in excess, there remains a red, dingy-looking mass,
which soon becomes green, and when heated till the sulphuric acid vola«
tilizes, leaves an insoluble, dirty-white basic salt. (Brandenburg.)
H. SuLPHATB OF Ohbomio AoiDl^-By mixing aqueous chromic acid
with sulphuric aeid, or by decomposing chromate of banrta or chromate of
lead with excess of boiling sulphuric acid, Gay-Lussao (Ann. Chm, Phy$*
1 6, 102; also Schw. 32, 447) obtained dark red, deliquescent prisms, which,
from his analysis, appear to consist of sulphate of chromic acid =: CrO'i
80'. — The experiments of Fritnche, however (p. 117, 4), confirmed by
Hagen and Plantamonr, have proved that these crystals are nothing more
than chromic acid, with from 8 to 10 per oent. of mechanically a&ering
sulphuric acid, which, by dryine the crystals on a brick or between folds
of blotting paper, may be redooea to 1 '8 per cent. IT Bolley {Ann. Fharm.
56, 118) finds that chromic aoid is less soluble in bihydrated sulphuric
acid than in the same acid of any other strength. When crystallised
chromic acid is thrown, by small portions at a time, into strong sulphuric
aoid, till no more is dissolved on agitation, a dark brown, oleaginous solu-
tion is formed, which afterwards becomes deep yellow and pasty. After
standing for a day or two, this liquid acquires a pale brown tint with a
IODIDE OF CHROMIUM. 129
tinge of green^ and becomes granular. When rapidly dried on burnt clay,
it yielded the following results:
Calculation. Boiler.
CrO« 52 .... 51-48 474
SO». 40 .... 39-61 42-8
HO 9 .... 8-91 9-7
CrO»,SC>» + HO 101 .... 10000 999
The excess of sulphuric acid probably arises from a portion of that sub-
stance adhering to the crystals. T
I. SuLPHOCARBONATE OF CHROMiUM.-^ulphocarbonate of lime gives
with salts of chromic oxide a greyish green precipitate, resembling
the hydrated sesquioxide. By distillation it yields bisulphide of carbon,
and a brown residue of sesquisulphide of chromium, which burns vividly
in the open fire, and forms chromic oxide. (Berzelius.)
1 Selenium and Chromium.
Selenite op Chromium. — a. Neutral Seleniie.-^CT^0\3Se0\ — ^Pre-
pared by decomposing chloride of chromium by selenite of ammonia. Soft,
green, amorphous powder.
CalculatioD. Muspratt.
Ci^O» 80 .... 32-26 .... 32-60
3ScO» 168 .... 67-74
Cr«03, 3SeO« 248 Z. 100*00
h. Acid Selenite, — Selenite of chromium dissolves in selenious acid,
yielding a green varnish on evaporation. (Muspratt, Qu, J. ofChem,Soc.
5, 62.) IT
Chromium and Iodine.
IT Protochloride of chromium is not precipitated by iodide of potas-
sium; but the mixture acquires a reddish brown colour. (Moberg.) IT
A. Iodide op Chromium ? — According to H. Rose {Pogg, 27, 575),
a mixture of bichromate of potash and iodide of potassium with oil of
vitriol yields nothing but iodine when distilled. Giraud, on the contrary,
thought that he obtained teriodide of chromium by the following process :
when a mixture of 33'5 parts of monochromate of potash and 165*5 parts
of iodide of potassium is mixed in a retort with 70 parts of oil of vitriol,
the mixture becomes strongly heated, gives off (besides sulphuric acid and
free iodine) deep red vaponrs; and after being sufficiently heated, leaves
a residue of sulphate of potash and sulphate of chromic oxide in the retort.
The red vapours condense into a deep red oil, which is heavier than water,
and boils at about 149% giving off a dense red vapour. The oil imparts
a deep brownish red permanent stain to the skin, and de8tro3rs the cuticle;
corrodes and blackens paper and wood; absorbs water from the air; and
yields with water a solution of chromic and hydriodic acids. (Giraud,
FhiL Mag, J, 12, 322.) — No analysis of this substance was undertaken.
A solution of bichromate of potash gives with excess of concentrated
hydriodic acid, a dense, black precipitieite, while a large quantity of free
VOL. IV. K
ISO CHROMIUM.
iodine is separated; tbe precipitate when drv resembles gam-klno^ and
dissolves in water, forming a green solution, (inglis.)
B. I0DI.TI OF Chromic Oxide. — lodate of soda produces in a soln-
tion of sesquiehloride of cbromiam, a dark blue, pulverulent precipitate^
which assumes a lighter colour when dry. (Berlin.)
Cheoxiux akd BnoxiNE.
IT Protochloride of chromium forms a dark green mixture* with bro-
mide of potassium. (Moberg.) Y
A. SBSaUIBROMIDB OP ChBOMIUM and Hn>BOBR0Ml.TB OF Ch&oxig
OxiDB.— 1. Metallic chromium heated with bromine in a ghiss tube, the
top of which is closed with the finger, does not absorb the bromine till it
is red-hot, at which time the bromine is of course in the state of vapour;
combination then takes place, attended with emission of light and heat.
The product is a greyish green, deliquescent mass, having a sweet and
rough taste. (Bertliemoti Ann, Chim. PhyB, 44^ 383; alsoJ^. Fkai^m, 16,
650^
The green solution of sesquibromide of chromium in water turns brown
on evaporation, and crystallizes with difficulty. When it is further evapo-
rated, the residue evolves hydrobromic acid, and at a dull red heat, vapours
of bromine are given off; exposure to a white heat converts it wholly
into se'squioxide of chromium. A similar solution is obtained by saturating
aqueous hydrobromic acid with hydrated chromic acid, in which case
bromine is set free. (Berthemot.) — By agitating chromate of lead with
aqueous hydrobromic acid and boiling the filtrate, a dark green solution
is obtained, which does not 3rield crystals on evaporation; but when eva-
porated to dryness and ignited, leaves a yellowish red powder. (Lowig.) —
Bromine- water partially converts the green hydrate of chromic oxide into
the brown modification ; the filtrate after evaporation deposits green crystals
of hydrobromate of chromic oxide. (Balard.)
When bichromate of potash is heatea with bromide of potassium
and oil of vitriol, bromine alone distils over, without a trace of cnromium.
(H. Rose, Fogg. 27, 575.)
B. Bromatb op Chromic Oxide.— Sulphate of chromic oxide is
precipitated by bromate of baryta and the solution filtered. — The green
filtrate evaporated over a water-bath soon gives off bromine, and assumes
a yellowish red colour, leaving a dark red, crystalline, deliquescent mass,
which consists almost entirely of chromic acid. (Rammelsberg, Fogg,
55, 87.)
Chromium and Chlorikb.
% A, Protochloridb op Chromium. — Formatum and Preparation,
— 1. By passing dry chlorine gas over a red-hot mixture of chromic oxide
and charcoal — sesquiehloride (q, v,) being formed at the same time.
(Peligot.) — 2. By passing hydrogen gas over perfectly anhydrous sesqui-
ehloride of chromium very gently heated, as long as hydrochloric acid
gas continues to be given off (Cr»Cl»+ H=HC1 + 2 CrCl). The hydrogen
must be freed from all traces of oxygen by passing it through a solution
SESQUICHLORIDB OF CHROMIUM. 131
of protoeliloridd of tin in caustic potash, then through tubes containing
sulphuric acid and chloride of calcium^ and lastly over ignited metallic
copper.
The protochloride obtained by the first method is in fine white
crystals, usually mixed, however, with charcoal and chromic oxide. The
second method yields a white velvety substance, which retains the form
of the sesquichloride from which it has been prepared.
CalcvUtioii. Peligot
1. 2. 3.
Cr 28-00 .... 44-16* 39-4 .... 42-7 .... 42*0
CI 35'4I .... 65-85 58*4 .... 56-7 .... 670
CKn 63-41 .... 10000 97-8 .... 99-4 .... 99*0
Protochloride of chromium dissolves in water, with evolution of heat,
and forms a blue solution, which, when exposed to the air, rapidly turns
green, from absorption of oxygen. It likewise turns green when ex-
posed to the action of chlorine. If kept out of contact of air, it gives
with caustic potash a brown precipitate of hydrated protoxide, accom-
panied by disengagement of hydrogen. With ammonia it gives a
greenish white precipitate, without evolution of hydrogen. With am-
monia and sal-ammoniac it forms a blue liquid, whicn turns red on expo-
sure to the air. Monosulpbide of potassium gives a black precipitate
containing sulphur, and insoluble in excess. — Ferrocjranide of potassium
gives a yellowish green precipitate. — The solution of protochloride of
chromium is one of the most powerful deoxidizing agents known. With
a solution of monochromate of potash, it gives a brown precipitate, pro-
bably consisting of chromoso-chromic oxide: if the protochloride be added
in excess, the precipitate disappears, and the liquid becomes green. It
precipitates calomel from a solution of corrosive sublimate. With a salt
of protoxide of copper, it gives a white precipitate of dichloride of copper;
but if it be added in excess, a red precipitate of dioxide of copper is
produced. It instantly converts tungstic acid into blue oxide of tungsten,
and precipitates metallic gold from a solution of the chloride, with evolu*^
tion of hydrogen.
Svhchlonde of Chrimium, — Obtained, accordin^to Moberg, by treating
a solution of the protochloride with ammonia. The precipitate cannot
be obtained free from ammonia; hence its composition has not been
determined. The supernatant liquid* retains its blue colour in close
vessels; but when exposed to the air, it is converted into ammonio-
chloride of chromium. The precipitate turns green in the air-— dissolves
with tolerable £Eu;ility in hydrochloric acid, the act of solution, if per-
formed in a close vessel, being attended with evolution of hydrogen.
(Moberg, Pharm. Centralb. 1848, 787.) IT
B. Sesquichloribe of Chromium. — 1. An aqueous solution of
ter-hydrochlorate of chromic oxide is evaporated to dryness, and the
residue heated to expel the last traces of water. (Vauquelin.) The
solid residue obtained at a gentle heat forms a bulky roso-coloured
powder, which, when strongly heated in a retort, evolves chlorine,
diminishes in volume, and is converted into yellow micaceous scales.
* According to Peligot, the atomic weight of chromium U 26-241, which gives for
the protochloride, 42'6 Cr+ 57*4 CI, agreeing very nearly with the results of analysis.
k2
152 CHROMIUM*
^Vauquelin.) — Evaporated at 100°, the solution leaves a dark green
aeliqueecent mass, which does not part with the whole of its water
even at 1 60", hnt remains unaltered. At a still higher temperature, it
loses water, swells up strongly, and assumes a peach-blossom colour; but
the last portions of water can only be expelled by exposure to a high
temperature, and their evolution is attended with partial decomposition
of the compound. Even when the residue is heated in an oil bath to
250", and a current of dry air passed over it, traces of water still remain;
at the same time, chlorine is evolved, and a portion of the sesquichloride of
chromium is converted by the oxygen of the air into chromic oxide, which
imparts a green colour to the mixture. (H. Rose.) — 2. Berzelins introduces
the residue obtained by evaporating hydrochlorate of chromic oxide into a
retort and heats it till it sublimes, whereby a small quantity only of hydro-
chloric acid is set free. Only the smaller portion sublimes as insoluble
chloride of chromium, the larger quantity remaining in the retort in the
soluble form. (Berzelins.) — Gaulthier de Claubry (Ann, Gh. Ph, 45, 110;
also Schw, 62, 217) by evaporating a solution of hydrochlorate of chromic
oxide to dryness, putting the dry residue into a porcelain retort, and
heating it to whiteness in a blast-furnace till the retort began to soften,
obtained a large quantity of sesquichloride of chromium sublimed in
peach-blossom coloured needles; a considerable portion, however, re-
mained un volatilized. — 3. The residue obtained as above by evaporating
a solution of hydrochlorate of chromic oxide, is ignited in a current of
chlorine gas. If the chlorine contains atmospheric air, sesquioxide of
chromium is also produced, with incandescence. (H. Rose.) — 4. Sulphide
of chromium is heated in a current of dry chlorine gas. (Berzelins; Fellen-
berg, Pogg, 50, 79.)— 5. Dry chlorine gas is passed over an ignited
mixture of sesquioxide of chroinium and charcoal. (Wohler, Pogg. 1 1,1 48.)
The heat of an argand spirit-lamp is sufficient for the purpose. (Wohler.)
— No higher chloride is formed even with a large excess [of sesquioxide ?J
and at very high temperatures. (H. Rose.) The chloride of chromium
being but slightly volatile, sublimes as it forms and collects in that part
of the tube which still contains charcoal. The mixture of chloride and
charcoal is therefore introduced into a fresh gloss tube, so as only to
cover the bottom, and strongly ignited in a current of chlorine gas.
The pure chloride of chromium sublimes into the upper portion of the
tube. (H. Rose.)
Sesquichloride of chromium has a soluble and an insoluble modifica-
tion; the former is obtained by the first method, the latter by the second,
third, and fourth (H. Rose); the fourth method yields a mixture of a
small quantity of soluble with a large quantity of insoluble chloride.
(Fcllenberg.) Both modifications have the lorm of brilliant, peach-blossom
coloured, micaceous laminss, which, when thin, transmit light of the same
colour. They leave a mark on the 'skin like talc. (H. Rose.) They
volatilize at a bright red heat. IT According to Peligot, the sesquichloride
by itself is perfectly insoluble in water, but when in contact with the
protochloride, it dissolves with ease, heat being evolved and a green solu-
tion formed: this solution exhibits all the characters of chromic salts.
A very small quantity, less than p7,-sinr> ^^ ^^^ protochloride is sufficient
to render the sesquichloride soluble : the protochloride appears to act
merely by contact. IT
Calculation.
2Cr 560 .... 34-52
3Cl 106-2 .... 66-48
Cr»Cl». 162-2 .... 100-00 10000 1000
Berzelins.
Fellenberg.
36-14 ...
• ...« 00*i
63-86 ...
64-8
8ESQUICHL0RIDS OF CHROMIUM. 133
Sesqaichloride of chromium ignited in the air evolyes chlorine, and is
first converted into oxychloride of chromium, and then into sesquioxide*
In the case of the soluble modification, the change is attended with
emission of light and heat. The insoluble variety, which does not glow,
leaves 47*54 per cent, of sesquioxide. (H. Rose.) The red sublimed
chloride of chromium heated in a stream of hydrogen gas as strongly as
the glass tube will bear, is converted, with loss of 24*57 per cent, of chlo-
rine, into a white substance, which is probably GrCl. (p. ISO) The
latter substance deliquesces in the air and becomes green; when mois-
tened with water it becomes heated, emits a smell of hydrogen gas, turns
green, and dissolves in water, with the exception of 7*5 per cent, of a
green powder, which, if treated with ammonia, assumes a deep blue colour,
and partially dissolves in it, forming a beautiful red solution. (Moberg,
tl*. pr, Chem. 29, 279.) — By ignition in phosphuretted hydrogen gas, the
sesquichloride is converted into phosphide of chromium. (H. Rose.)
When heated with sulphur (Lassaigne) or in a stream of hydrosulphuric
acid gas (Liebig), it yields sulphide of chromium. Ignited in ammoniacal
gas it yields nitride of chromium. (Schrotter.) When fused with carbo-
nate of soda and sal-ammoniac, it yields, not metallic chromium, but
chromic oxide in crystalline spangles. (W&hler.) The soluble chloride of
chromium is readily decomposed by alkalis. The insoluble variety is
acted on with difficulty by a boiling solution of caustic potash, and with
still greater difficulty by a boiling solution of carbonate of potash or soda;
solution of ammonia has no efiect upon it. (H, Rose.) According to
Fellenber^, boiling caustic potash or soda and their carbonates easily
remove the hydrated oxide. The soluble chloride is immediately de-
composed by warm sulphuric acid, yielding hydrochloric acid and solid
sulphate of chromic oxide. The insoluble chloride is not decomposed by
boiling sulphuric acid either concentrated or dilute, nor even when heated
with anhydrous sulphuric acid, which volatilizes without acting upon it.
(H. Rose.) Boiling hydrochloric, nitric, and nitro-hydrochloric acid, like-
wise have no action on this substance. (Fellenberg.) — IT According to
Jacquelain — ^who regards the violet chloride before washing as a compound
of protochloride and sesquichloride of chromium — it is soluble in 2,000
parts of water at 90^ in 1000 parts at lOO""; and in 68 parts at 136''
under pressure. Moreover, it is slowly decomposed by sulphuric acid
at ordinary temperatures, and more rapidly with the aid of heat, hydro-
chloric acid being evolved, and a green solution obtained. Sulphurous
acid likewise decomposes it in close vessels, forming a green solution. IT
Hydrated Sesquichloride of Chromium, or Terhydroddorate of Chromic
Oxide, — 1. Formed by dissolving the sesquichloride of chromium in water.
The soluble modification, even after being heated to 250^, deliquesces
rapidly in the air,' and yields a dark green solution. The insoluble
chloride difiuses itself in water in fine soiJes, but even after long con-
tact, a mere trace only is dissolved, producing a greenish colour in the
liquid. (H. Rose.) — 2. By dissolving the hydrated sesquioxide in aqueous
hydrochloric acid. — 3. By boiling chromic acid with hydrochloric acid.
4. By boiling red chromate of lead in hydrochloric acid, evaporating, and
dissolving out the chloride of chromium by means of alcohol; or by
boiling the mineral with hydrochloric acid and alcohol, and filtering the
liquid. The solution appears dark green by reflected and red by trans-
mitted light — IT 5. According to Peligot, this solution, when evaporated
in vacuo, leaves an amorphous mass, which dissolves in water with dis-
engagement of heat; and consists of Cr'CP; 6H0. When a solution of
134 CHROMIUM.
the iosolnble violet chloride in water containing protoehloride is slowly
evaporated in vacuo, green (needle-formed, Moberg) crystals are obtained i
which are very solable in water, and consist of Cr'Cl' -h 1 2H0. IT
On looking through a stratum of the above solution a line in thick-
ness, the flame of a candle appears red; the sun and objects illnminated
by it, even green leaves, appear rose-coloured; the clouds not directly
iUnminated by the sun, white; and the sky itself, g^eyish-blne. (Gmelin.)
The thinner the stratum of liquid, the more highly must it be concentrated,
in order to transmit candle-light red; if the solution be too dilute or the
stratum too thin, the light appears green; indeed the colour varies with the
method by which the solution is prepared. For instance, the solution
obtained by boiling chromate of lead with hydrochloric acid and alcohol
appears red at a much greater degree of dilution and in a much thinner
stratum, than the saturated solution of hvdrated chromic oxide in hydro-
chloric acid ; next to the latter stands the solution obtained by treating
chromate of lead with hydrochloric acid and alcohol in the cold. A solution
diluted till its density is reduced to 1*010, and kept for a long time at a
temperature of 70^, acquires the property of appearing red by transmitted
candle light, eren when in very thin strata : if, however, it is evaporated
or boiled for some time, it appears green by candle-light. (Moberg.)
The solution of sesquichloride of chromium has a sweet and after-
wards rough taste. If slowly evaporated and afterwards heated to 100%
it leaves a dark green hydrated mass, which, according to Liebig, swella
up strongly at a temperature of 200*^.. ..800% and is converted into red
soluble chloride of chromium.
C. OxYGHLORiDB 07 CHROMitTM. — By bolling hydrochloric acid with
an excess of hydrated chromic oxide, nothing but a solution of Ci^CP is
obtained.— a. 2Cr^CP, Gr'O^— 1. A solution of sesquichloride of chromium
evaporated and dried at 120% swells up and crumbles on stirring, to a
reddish-grey powder which deliquesces in the air. — 2. If the substance
be dried at 150% with constant stirring, a greyish-red powder is obtained^
which, when treated with cold water, leaves a rose-coloured residue.
This latter compound dissolves in warm water; its analysis is given under
(2) below. — 3. If the solution is evaporated over oil of vitriol, the hydratea
compound remains in the form of a dark red mass: analysis 3. (Moberg.)
IT A solution of this compound gives with iodide of potassium a yellow,
and with sulphite of potash, a blue greyish-green precipitate; with other
salts it gives similar reactions to the neutral chloride. (Moberg.) IT
Moberg.
Calculation. (1) (2)
2Cr«CP 324-4 .... 80-22 8M1 .... 81-62
C^Cfi 80-0 .... 19-78 18-89 .... 18*48
2Ci3CP + Cr»0' .... 404-4 .... 100*00 100*00 .... lOOOO
Moberg.
(3)
2Ci*Cl» 324-4 .... 66-83 66-76
Cr«0» 80-0 .... 16-48 16-93
9HO 81-0 .... 16-69 17-31
+ 9Aq 485-4 .... 100-00 ZZ lOO'OO
h, Cr*CP, 2Ci*0*. The greyish-red powder obtained at 150* /B, a, 2),
when strongly heated becomes gradually darker without sweuing «p>
CHROMATE OF TEBCHLORIDE OF CHROMIUM. 1S5
after being heated nearly to redness, it dissolres bat partially in water;
the insoluble portion appears greyish-red by daylight, and green by
candle-light; its composition is given below. By long continued ignition
in the air, it is completely converted into the sesquioxide. (Moberg, «/*.
pr. Ckem. 29, 178.)
Calculation. Moberg.
Cr»Cl« 162-2 .... 50-31 50*53
gCigpa 1600 .... 49-69 .; 4947
Cr^CP, 2Ci:303 3222 .... 10000 10000
By dissolving the brown hydrated oxide of chromium in hydrochloric
acid, a red solution is obtained, which, by the agency of light, or by boiling
with hydrochloric acid, or by evaporation, is converted into green
hydrated sesauichloride of chromium with evolution of chlorine. (Berze-
lius, Brandenburg.)
D. Chlorochiiomic Acid. — Cliromaie of Terchlonde of Chromium,
— This compound was formerly regarded as terchloride of chromium, till
H. Rose discovered the chromic acid present in it. It is formed by dis-
tilling a salt of chromic acid with common salt and oil of vitriol in excess.
1. Ten parts (3 atoms) of common salt are fused with 16*9 parts (3 atoms)
of monochromate of potash; the resulting mass is broken up into large
fragments and introduced into a capacious, long-necked, tubulated retort,
and 30 parts (12 atoms) of fuming oil of vitriol poured upon it. The
powerful' heat evolved on mixing the ingredients is sufficient to drive
nearly the whole of the new compound over into the receiver, which must
be kept cool by moistened paper; that which passes over subsequently, on
the application of heat [to be collected in a separate receiver], amounts to
a small quantity only, and contains sulphuric acid. In the retort there
remains a mixture of bisulphate of potash and soda» having a slight green
tin^. (Wohler, Po^g. 33, 343.)
3(KO, CrQS) + SNaCl + 12CHO, S0>) = 3(KO, 2S03 + HO) + 3(NaO, 2S0» + 3H0)
+ CrCP, 2CrO».
Three atoms of water are here assumed as existing in bisulphate of
soda; which agrees with the determination of Brandos. (III., 104.) The
fact that free cnlorine is always disengaged in this process, and a portion
of free chromic oxide found in the residue, proves that the decomposition
partly takes place as follows :
3N»C1 + 2(KO, CrO^ + 13S0» « 3(NaO, 2S0*) + 2(KO, 2S0») + Ci«0', 3S0»+ 3a.
The water which is present appears to give rise to this mode of
decomposition. Walter (Ann, Chim. Phys, 66, 387; also Fogg. 45, 154),
uses the same proportions, but introduces the oil of vitriol into the retort
gradually, and through an S-tnbe, so that the mass may not boil over;
and in order to condense the vapours perfectly, he cools the neck of the
retort and receiver with great care, so that nothing but free chlorine may
escape; and lastly, applies a gentle heat to the retort till yellow instead
of red vapours appear. Bichromate of potash may also be used in place
of the monochromate. (Wohler, H. Rose.) Thomson uses 12 parts of
bichromate of potash and 10 parts of common salt.
2. Dumas {Ann. Chim, Phys. 31, 435) distils common salt with
chromate of lead and oil of vitriol, and condenses the vapours in a tube
oooled to a yexy low temperature. The distillate contains an excess of
136 CHROMIUM.
chlorine, which it has absorbed, and if the receiver is kept very cold, the
?nantitj of that element is so great, that the liquid partially solidifies,
bamas, H. Rose.) The compound is purified by partial distillation,
whereupon the excess of chlorine is evolved and the sulphuric acid left
behind in the residue. (Walter.)
Splendid blood-red liquid, which appears black by reflected light; at
2V its specific gravity is 1*71; and under a pressure of 0*76 metres,
(= 29*92 in.), its boiling point is constant at IIS*". (Walter.) Its
vapour has the colour of hyponitric acid gas. [For the specific gravity
of the vapour^ see I., 280.]
CalculatioD.
CrCl» 134*2 .... 56*34
2CrO» 104*0 .... 43-66
CrCl». 2CrO»
238-2
•
.... 1000(
U. Rose.
35*53
45*60
)
Or:
3Cr
84*0 ....
. 106*2 ....
48*0 ....
35*27
44*58
2015
Walter.
■ ••• o9 aO
3C1
60
.... 4514
Vapour
Chlorint
288-2 ....
of chTl>nimin ? „.,
lOO'OO
V<
)lume.
1
1
1
Sp.gr.
1-9404
5 M8 ....<
2*4543
Oxygen
* 6""" •••"
1-1093
6^ "
Vapour of chloro-chromic add 1 5*5040
The compound may also be regarded as CrO^Cl, or as chromic acid in
which one atom of oxygen is replaced by one atom of chlorine; according
to this view, Walter calls it Chlonhoxyckromic acid.
The vapour passed through a red-hot tube is decomposed into crystal-
lized chromic oxide (p. Ill) and chlorine and oxygen gases. (Wohler.)
2(CrO«Cl) = Cr205 + O + 2C1.
This compound explodes with phosphorus, the explosion being attended with
emission of light. (Dumas, Walter.) A single drop of the liquid with a
piece of phosphorus of the size of a pin*s head, is sufficient to produce this
efiect. (Dumas.) The phosphorus must be moistened to produce the
explosion; wben dry it is without action, and ignited phosphorus is
extinguished in the vapour of the compound. (Thomson.) Sulphur
decomposes the compound with a hissing noise. (Dumas.) Flowers of
sulphur moistened with it take fire after a few minutes, and bum with a
rea flame. (Thomson, Phil. Mag. Ann. 1, 452; also Kastn. Arch. 11,
217.) Sulphur separates a rose-coloured powder, (Kemp, J. Pharm. 20,
413), which, according to Gregory, has the same composition and pro-
perties as the insoluble sesquichloride of chromium. If sulphuretted hy-
drogen is passed into the compound, the tube containing it becomes red-hot;
hydrochloric acid gas is evolved, and a green powder separated, which is
probably sulphide of chromium. (Kemp.) The compound violently decom-
poses terchloride of phosphorus and dichloride of sulphur, with evolution
of a large quantity of vapour and precipitation of the rose-coloured,
insoluble sesquichloride of chromium. If the vapour of chlorochromic
acid is allowed to pass throneh a narrow tube into a vessel filled with the
vapour of dichloride of sulphur, vivid combustion takes place, and the
rose-coloured powder is deposited, (Kemp.) In ammoniacal gas the com-
SESQUIFLUORIDB OF CHROMIUM. 13^
pound solidifies with brilliant incandesoence, forming a dark brown mass,
which remains red-hot for some time. (Thomson.) The tube in which
the ammoniacal gas is made to act on the substance, exhibits a purple-
red glow for a long time. If more ammoniacal gas is passed over the
ignited residue, it changes to a black powder. rLiebig, Pogg, 21, 359.)
This substance is nitride of chromium. (Schrbtter.) According to Persoz
{Ann, Chim. Fhys. 44, 328), the mass saturated with ammonia is a com-
pound of 79'1 per cent, of terchloride of chromium, and 20*9 of ammonia.
Merounr acts yiolentlj on chlorochromic acid. (Dumas, Walter.)
When defiant gas is pcused through this compound, it rises in tempera-
ture, evolves vapours of oil of olenant gas, becomes opaque and brown,
and is finally converted into a dark brown powder, which appears
to be CrCR The powder deliquesces in the air, forming a greenish
brown liquid, from which ammonia precipitates a greenish brown oxide,
while chromate of ammonia remains in the solution. If air is admitted
at the same time with the defiant gas, combustion ensues, the whole mass
becomes ignited, and is converted into green chromic oxide, while dense
fumes are given off. (Wohler, Pogg, 13, 297.) If the compound is intro-
duced in a basin into defiant gas previouslj set on fire, continuous com-
bustion ensues, without any separation of carbon. (Kemp.) With
absolute alcohol, the compound generally evolves sufficient heat to pro-
duce combustion, attended with formation of heavy hydrochloric ether
((>H^C1) and a green solution of sesquichloride of chromium. (Wbhler,
Thomson.) A small quantity of the compound mixed with absolute
alcohol sets it on fire, with explosion and violent projection of the liquids.
(Walter.) Oil of turpentine is likewise inflamed by the compound, and
wood-spirit, camphor, and olive oil, are rapidly decomposed. (Thomson,
Phil, Transact. 1827; also Pogg, 31, 607.) Charcoal and indigo do not
affect it. (Dumas, Thomson.) The compound sinks in water, and dis-
solves with evolution of heat sufficient to produce ebullition; the solution
is found to contain chromic and hydrochloric acids. (Dumas, Walter.)
Chlorochromic acid dissolves iodine without being decomposed.
(Walter.) It absorbs chlorine gas in abundance at ordinary tempera-
tures, forming with it a brown, almost solid mass, which, when exposed to
the air, emits dense reddish fumes having the odonr of iodine. It dissolves
in water with a hissing noise, and gives off its excess of chlorine. (Dumas.)
E. Aqueous Hydbochlorate of Chromic Acid. — 1. Formed by
dissolving chlorochromic acid in water. — 2. By decomposiug chromate of
lead or silver at ordinary temperatures with excess of h3'^drochloric acid.
Brown uncrystallizable liquid which dissolves gold; when heated, it
evolves chlorine and is converted into sesquichloride of chromium. (Moser.)
When evaporated, it gives off reddish yellow vapours, and leaves a
brownish black, shining, uncrystallizable mass. (Berzelius.)
Chromium and Fluorine.
IT A. Protofluoride of Chromium.— Greenish precipitate, which
leaves the supernatant liquid nearly colourless. (Moberg.) IT
B. Sesquifluoridb of Chromium and Hydrofluatb of Chromic
Oxide. — 1. By dissolving chromium or the hydrated sesquioxide in
aqueous hydrofluoric acid, a green solution is obtained, which, on evapora-
tiou; leaves a green crystalline mass, perfectly sdable again in water. —
1S8 CHROMIUM.
Y 2. Aoooxdinff to Moberg, aoBquichloride of duromium gives a green
precipitate wiUi fluoride of potassium. IT Sesquifluoride of chroroiam
nnites with more basic metallic fluorides, forming grass green, pulveru-
lent compounds, which, for the most part, are very sparingly soluble in
water, but generally speaking, do not separate from the mixed aqueoua
Bolations without the application of heat. (Berzelius.)
C. The brown hydrated sesquioxide yields with aqueous hydrofluoric
acid a rose-colonred solution which dries up to a rose-coloured salt; this
salt redissolves completely in water, and gives a brown precipitate with
ammonia. (Berxelius, Pogg. 1, 34.)
D. Terfluoripe of Chromium. — A mixture of one part of chromate
of lead with one part of fluorspar and 3 parts of fuming oil of vitriol is
distilled in a tubulated leaden retort, and the vapours collected in a leaden
receiver attached to the retort. (Unverdorben.) Instead of chromate of
lead, bichromate of potash may also be osed. (H. Rose.) According to
Dumas (Ann. Chim, Phyz, 31, 435), the vapours may be condensed by
the application of cold.
Red vapour, the inhalation of which produces severe oppression of
the lungs. (Unverdorben.)
The vapour is decomposed by water, with rise of temperature, into
hydrofluoric and chromic acids. Hence, when exposed to the air, it
evolves finely crystallized chromic acid in the form of a red and subse-
quently of a yellow cloud; it likewise imparts a coating of chromic acid
to moist porous substances, which, when they are of organic nature,
sometimes become green by deoxidizing the chromic acid. Silica, even
as it exists in glass, converts terflnoride of chromium into gaseous
fluoride of silicium and chromic acid. Consequently, on distilling the
above-mentioned ingredients in a glass retort, fluoride of silicium is
obtained, and chromic acid (containing hydrofluoric acid, however) sub-
limes into the neck of the retort. Boracic acid decompose* this com-
pound, forming fluoride of boron and chromic acid; and arsenious acid
converts it into fluoride of arsenic and chromic acid. Mercury decom-
poses the vapour veiy slowly, forming a pulverulent substance. Organic
bodies are destroyed by the vapour, which combines with their hydrogen
and oxygen; alcohol and ether, under these circumstances, produce
faydrofluate of chromic oxide. (Unverdorben^ The vapour passed into
absolute alcohol deposits large quantities or a brownish green powder
with emission of heat (Wohler.) Terflnoride of chromium combines
with ammonia. (Unverdorben.)
CrF' should contain in 100 parts: Chromium 33*29, Fluorine 66*71.
H. Rose, however, by slowly passing the vapour into water and esti-
mating the quantities of chromic and hydrofluoric acid produced, fonnd
the proportion of chromium to fluorine, in one experiment, = 24'73 : 75*27;
and in a second, = 26*41 : 73*59. At the same time he observed that
the vapour was not entirely absorbed, but that oxygen gas remained, and
further, that sulphates of the green and brown oxide of chromium were
present in the retort, besides sulpbate of potash and sulphate of lime.
This deviation of the analysis from the calculation may be explained in
two diflerent ways : 1. The pure compound is really CrF', but its vapour
is mixed with oxygen gas and hydronuoric acid vapour, the latter being
evolved in the free state by the action of the hydrated oil of vitriol on the
fluoxspat. When this gajseous mixture is passed into water, the latter
! NITRIDE OV CHKOMIUM. 139
absorbs variable quantities of HF^ in addition to tbe GrF'^ and conse-
qaentlj the analysis of this liquid gives an excess of fluorine. — 2. The
compound is CrF*, which in 100 parts amounts to Cr23-04 4- F 76'9e. This
CrF^ would be decomposed with 5H0, into Cr0^5HF, and 20; whence, in
the absorption of the vapour by water, free oxygen gas must be left
behind. [The presence of this gas, however, has already been sufficiently
explained by the formation of chromic oxide in the residue of the dis-
tillation.] H. Rose regards the latter view as the more probable, because
the excess of bichromate of potash must prevent the disengagement of
hydrofluoric acid. Berzelios declares himself, with reason, in favour of
the former theory.
E. Hydrofluate of Chromic Acid. — The yellowish brown solution
obtained by decomposing the terfluorido of chromium by water. This
solution, when evaporat^, gives off the hydrofluoric acid, — the greater
part, according to Unverdorben ; the whole, according to Berzelius. Zinc,
tin, and other metals convert it into hydrofluate of chromic oxido and
separate the oxygen.
CHROMnTM AND NiTROOBK.
A. NiTRiDB OF Chromium.— Liebig {Poffff. 21, 359), by igniting
sesqnichloride of chromium in ammoniaoiu gM, obtained a brown powder,
which he regarded as chromium. Schrotter described it as nitride of
chromium. It is prepared by passing dry ammoniacal gas over sesqui-
chloride of chromium heated m a ^ass tube. (Liebig, Schrotter.) To
obtain the sesquiohloride as free as possible from sesquioxide and water,
it is previously heated in the glass tube in an oil bath, and a current
of hydrochlonc acid gas passed over it till no more water is evolved;
the tube is then cooled, and ammoniacal gas passed through it for a
long time; after which heat is applied, and the current of ammoniacal
gas kept up till no more sal-ammoniac is sublimed. The mass, when
cold, is removed from the tube, crushed, and again treated with ammonia,
the whole process being repeated several times. (Schrotter.) When
chlorochromic acid is treated in the same way with ammonia, a black
nitride of chromium is obtained, probably of similar composition.
(Schrdtter.)
S(Ci«Cl*) + 13NH» = 2Ci»N« + 9(NH<C1) 4- 3H.
Brown powder. (Liebig, Schr5tter.) Inflames in a current of oxygen
gas at a temperature between 150** and 200^, burning with a red light,
^ and evolving nitroeen gas and a small quantity of hyponitric acid
vapour; the residue is sesquioxide of chromium. (Schrdtter, Ann. Pharm,
37, 148.)
Calmlatiop. Schrotter.
3Cr ......^... — 84 .... 75 76*32
2N ^ 28 .... 25
CrtP 112 .... 100
[Schrotter fonnd that 562 parts of nitride of chromium heated in a
onrrent of oxygen gas jrielded on the average 612*74 parts of chromic
oxide. In these 612*74 parts, Schrotter supposed, from an error in cal^
eolation, that only 359*47 parts of metallic chromium were present (there
being in reality 429). Accoxdinglyi he concluded that 562 parts of
140 CHROMIUM.
nitride of chromium contain 359*47 (4 atoms) of chromium^ and 202*53
parts (5 atoms) of nitrogen^ corresponding to the formula Cr*N'.]
B. Nitrate op Chromic Oxide. — Prepared by dissolying the hjdrated
sesquioxide in nitric acid. The solution is blue by reflected^ and red
by transmitted light. Has a sweety astringent taste; does not yield
crystals on eraporation^ but dries up to a gummy, fissured mass^ which
appears dark green both by reflected and transmitted light. After
exposure for several hours to the heat of a water-bath, it dissolves par-
tially in water, yielding a brown solution. (Hayes.)
C. Brown Nitrate of Chromium. — If the ^een chromic nitrate
is evaporated to dryness, and gently calcined, it swells up, evolves
nitrous acid vapours, and turns brown; after this, it forms a brownish red
solution in water. (Berzelius.) The yellow solution of the brown hydrated
oxide in nitric acid of specific gravity of 1' 18 leaves, when evaporated at a
gentle heat, a blackish brown mass, which becomes moist in the air and
dissolves completely in water. (Brandenburg.)
D. Nitrate of Chromic Acid. — Formed by mixing nitric acid with
chromic acid, or by precipitating a solution of chromate of baryta in nitric
acid, with the exact quantity of sulphuric acid required, and filtering
the liquid. On evaporating the solution, a brownish red or yellowish red
crystalline powder is obtained, having a very acid and rough taste. This
powder fuses when heated, and is converted first into brown nitrate of
chromium, and lastly into the green oxide. With oil of vitriol it gives
ofi* nitric acid fumes, whereby it is distinguished from pure chromic
acid. Deliquesces in the air; yields a brown solution with a small
quantity of water, and a yellow solution with a larger quantity. (Bran-
denburg.) When a solution of chromate of potash, likewise containing
nitre, such as that obtained in the treatment of chrome-iron ore (p. 108)
is precipitated by a salt of baryta, the chromate of baryta which separates
contains a portion of nitric acid intimately combined, and therefore, when
decomposed by dilute sulphuric acid— -even without being dissolved in
nitric acid — ^yields chromic acid containing nitric acid. (Brandenburg,
Meissner, Moser.) Richter, by precipitating chromate of potash with
nitrate of silver, and decomposing the precipitate by a quantity of hydro^
chloric acid insufficient for complete saturation, likewise obtained a
chromic acid containing nitric acid; because chromate of silver, according
to Brandenburg and Moser, likewise combines intimately with nitric acid.
According to Brandenburg, and Meissner also, the precipitate produced
iu chromate of potash by nitrate of lead contains traces of nitric acid.
E. Chromic Oxide and Ammonia. — Chromate of Ammonia, — a. If a
salt of chromic oxide is mixed with an excess of ammonia, a portion of the
precipitated oxide dissolves in the ammonia, even when kept out of contact
of air, and forms a peach-blossom coloured or columbine-red solution. The
more concentrated the ammonia and the greater its excess, the larger is the
quantity of oxide dissolved. It dissolves much more abundantly when
the chromium-salt is 'dropped into the ammonia than in the contrary case,
because the oxide, at the moment of its separation from the acid, is taken up
by the ammonia. Under favourable circumstances, 0*4 percent, only of the
chromic oxide remain undissolved. It appears that the chromic oxide
must first be converted by the ammonia into a peculiar modification (from
CHROMATE OF AMMONIA. 141
the green into the pnrple) before it can dissolve in the ammonia. If a
solution of chrome-alam is evaporated with a small quantity of oil of
vitriol to a small bulk, and the mixture dropped into an excess of
ammonia, less than 0*2 per cent, of chromic oxide remains undissolved.
The ammoniacal solution exposed to the air, deposits a violet-coloured
Wdraie, the solution of which in sulphuric acid becomes green on boiling,
(Hertwig, Ann. Pharm, 45, 299.)
6. The precipitate produced bv excess of ammonia in salts of chro-
mic oxide, is not pure hydrated sesquioxide, but contains ammonia,
even after prolonged washing with hot water: the ammonia may be libe-
rated by potash.
This compound exhibits two modifications, according to the manner in
which the ammonia acts in producing it.
a. Green Precipitate. — One measure of ammonia, of specific gravity
0*984, is added, drop by drop, to a saturated solution of chrome-alum.
The precipitate is of a pale green colour. It does not change its colour
after remaining three days in contact with the ammonia, unless the
ammonia is in very large excess, in which case it is partially converted
into p. Even after the digestion with ammonia, it yields with sulphuric
acid a violet solution, which becomes green on boiling; the same solution,
when saturated as nearly as possible with ammonia, without a precipitate
being produced, assumes a grass-green colour; with a larger quantity of
ammonia, and also with phosphate of soda, it gives a green precipitate.
This is the same modification of chromic oxide as that which occurs in
chrome-alum.
/9. Violet Preciptiate.'^The solution of chrome-alum is dropped into
ammonia — ^the same proportions being employed as in a — and the greyish
violet precipitate (the solution of which in sulphuric acid is also violet,
but becomes green on boiling) is kept for three days in contact with
ammonia in a stoppered bottle, whereupon, a portion dissolves, forming a
red solution. The undissolved portion of oxide is violet. A solution of
the nnwashed precipitate in sulphuric acid has a wine-red colour. With
carbonate of soda it yields, after a while, a dark violet precipitate. It
retains its wine-red colour when saturated as nearly as possible with
ammonia; after which, on dilution with water, it deposits a rose-coloured
precipitate. With phosphate of soda it gives a violet precipitate which
turns green at the boiling-point. Ammonia in excess precipitates a. violet-
coloured hydrate containing ammonia. When boiled, the red solution
becomes violet or green; after which, both ammonia and phosphate of
soda throw down a blue precipitate. This red modification is also per-
fectly formed in the red ammoniacal solution of chromic oxide.
When the green or violet precipitate « or /3 is freed by washing and
drying from the greater part of the ammonia which produced that modi-
fication, » dissolves at once in sulphuric acid, forming a green solution,
and /9 a violet solution ; but the latter also turns green on boiling. The
same change is effected by boiling the violet precipitate /3 in the ammo«
niacal liqnid from which it is precipitated — so that it vields with snlphurio
acid a violet solution which turns green on boiling. (Hertwig.)
F. Chromate of Ammonia. — a. i/onoc&romoftf. -— Prepared by
evaporating a mixture of chromic acid with a slight excess of ammonia.
Crystallizes in lemon-yellow needles, having an alkaline reaction and a
pungent saline taste; they are permanent in the air, and very soluble in
water. When heated, they retain a portion of the ammonia, till they are
143 CHROMIUlf*
entirely c<mTerted into cbromic oxide; and their aqneons solation, after re-
E sated eYaporation, readily depoBita portions of brown oxide. ( Vauqaelin,
ichter, Moser.) When rapidly heated till decomposition takes plaee^
the salt exhibits incandescence^ and is converted into the green sesqai-
oxide; if the temperature is slowly raised, the decomposition is not
attended with emission of light and heat, bat nevertheless takes place
suddenly throughout the whole mass, an oxide being left which dissolves
in concentrated acids with tolerable fiicility* (Maus.)
CryttttUiztd mid drUd 09€t oil qf vitrioL Kopp.
NH» 17 .... 21-79
CrO» 52 .... 66-67 .,.,.... 66-3
HO 9 .... 11-54
NH«,HO,CrO> 78 .... 100-00
b. Bichromate. — Crystalline system, the oblique prismatic. Fig. 86;
with the i-face frequently rounded off; « : ti or u' = 114^; t : A = 110°
IC; t : /(backwards') = 101° 58'; t : w = 122° 31'; v} : u = 98° 8';
t£ : m = 139° 4'; u : A = 135° 47'; cleavage parallel to m and t. (Brooke,
Ann. Phil. 22, 287.) Forms orange -yellow plates, which redden litmus,
have a saline taste, are permanent m the air, and less readily soluble in
water than a. (Moser.) The salt crystallizes in reddish-brown, rhombic
prisms, which, at a temperature below redness, are decomposed with
emission of li£;ht and feeble detonation, leaving a residue of chromic
oxide. (Hayes.)
H Darby has analyzed this salt, prepared by partially saturating
chromic acid with ammonia, and eraporatinff to the crystallizing point,
and finds that it contains NH', combined with the 2 equiv^ents of
chromic acid, instead of NH^O, as in the monochromate. {Ann. Fharm.
65, 204.) IT
Calculation. Darby.
NH« 17-0 .... 1405
2CrO» 1040 .... 85-95 .... 8496 85*2
NH»,2CrO» 1210 .... 10000
G. Carbonatb of Chromic Oxide and Ammonia. — Carbonate of
chromic oxide dissolves very sparingly in an aqueous solution of carbonate
of ammonia, forming a pale greenish-blue solution.
H. Tersidphide of Chromium with Eydroiulphate of Ammonia f—
Chromic acid yields with very dilute bi-hydrosulphate of ammonia a
brown solution which contains the sulphur-salt, and at the same time a
ffreyish-green precipitate, which, after being washed and dried, behaves
like a mixture of hyd rated chromic oxide and sulphur, — but at the moment
of its formation, dissolves in potash (not in ammonia, or bi-hydrosulphate
of ammonia), forming a green solution, and leaving a residue of hydrated
sesquioxide. With acids, the solution evolves sulphuretted hydrogen
and deposits sulphur, while a salt of chromic oxide remains dissolved.
(Berzelius.)
I. SuLPHATB OF Cbromio Oxidb AND Ammoni A.— ^mmonta Chrome*
aZum.<»-Prepared by mixing tersulphate of chromic oxide with ammonia.
(Mitscherlich.) — If sulphate of ammonia is added to a concentrated solu-
tion of the blue crystallized tersulphate of chromic oxide (p. 127), the
CHROMATS 07 SAI^AMMONIAC. 14S
double mJI u immediately precipitated in'the crystalline fonn; it' is purified
by a second crystallization after the removal of the mother-liquid.
(Schrotter.)
Regular octohedrons (Mitscherlich), having likewise the faces of the
cube and dodecahedron. Specific gravity 1*736 at 21 ^ (Schrotter.)
Cleavage indistinct, parallel to the octohedral faces. Fracture conchoida!,
with a vitreous lustre. Colour brilliant violet-blue, passing into colum-
bine-red (ruby-red by transmitted light, Sehrbtter). Streak, very pale
lavender-blue. Slightly transparent. Taste, slightly sweetish and saline.
(Hardinger, Bdinb. J. of Sc, 1, 100.)
Calculation. SchrOtter.
NH« 17 .... 3-53
Ci»0» 80 .... 16-69 .... 16-26
480» 160 .... 33-20 .... 3310
25HQ 225 .... 4668
NU<,HO,80*-fCiSO*,360*-«-24Aq. 482 .... 10000
The salt effloresces superficially in the air, and becomes covered with
a pearl-grey powder. Fuses at 100% forming a green liquid which
shows no signs of dichroism; 18 atoms of water are evolved at the same
time. On cooling, the salt solidifies in a pale green mass, which does not
part with the remaining portion of water till it is heated to above 300^.
— It dissolves in cold water, forming a blue solution, which at 75° or 80°
assumes a grass-green colour, because the alum is decomposed at that
temperature; — so that the solution yields no more crystals on evaporation,
but dries up to a green mass, and is moreover no longer precipitated by
alcohol, but either mixes with it, or, when concentrated, forms a substra-
tum, the alcohol floating on the surface. But if the solution, after being
turned green by heat, is diluted with water, and left to stand for ten
days, the alum is gradually reproduced. Alcohol precipitates the alum
from its solution in water. ^Schrotter, Fogg, 53, 526.)
When a solution of the olue crystallixed tersulphate of chromic oxide
is mixed with excess of sulphuric acid, then treated with alcobol, and the
green solution decanted from the precipitated blue salt, and mixed with so
much ammonia that it still remains slightly acid, a dark ffroen, highly acid
solution separates to the bottom ; and subsequently, after long standing, the
liquid becomes decolorized, and a light green salt is deposited, which, for
every 14 atoms of sulphate of ammonia, contains one atom of chromic
oxide in combination with 6 atoms of sulphuric acid and 33 atoms of
water. (Schrotter.)
K. Ammonto-4erJltu>rtde qf CAromit^m^-^Ammoniacal gas condenses,
according to Unverdorben, with fluoride of chromium, forming a yellow
Eowder, which sublimes without decomposition. According to Berzelius,
owever, the vapour of fluoride of chromium explodes wiUi ammoniacal
gas, the products being nitrogen and hydrofluoric acid.
L. SESaUIFLUORIDE OF CSROMIUM -I- HtDROFLVATB OF AmHONIA.
^-Oreen, sparingly soluble powder. (Berzelius.)
M. Chromatb of Sal-ammoniac. — Formed by adding chlorochromic
acid to a concentrated solution of sal-ammoniac. The crystals have the
same form and appearance as the corresponding potassium compound, but
are much more soluble in water. (Peligot, Ann, Chim, Phy$, 52, 267; also
J. Fharm. 1 9, 301 j also Ann, Fharm. S, 1.)
144 CHROMIUM.
Cslcolation. Peligot
NHS 17.0 .... 10-80 10-8
Ha 36-4 .... 23-13 23-5
2CrO» 1040 .... 66-07 65-5
NH',HCl,2CrOS 157*4 .... 10000 ~. 99^
Chromium and PoTABsniM.
A. Chromic Oxide and Potash. — ChromUe of Potcuh.^^K cold
aqaeous solation of potash dissolres hydrated chromic oxide^ forming a
grass-green solution. This liquid^ unless it contains a large excess of
potash, deposits a jelly after some time, leaTing the supernatant liquid
colourless; when heated to the boiling point, it also becomes colourless,
green flakes being precipitated. According to Moser, however, a small
ouantitj of chromate of potash, produced by the action of the air, remains
dissolved. Boudault {Ann. Pharm. 59, 351) has obserred that a solution
of chromic oxide in potash is conrerted into chromate of potassh by the
addition of ferricyanide of potassium.
The brown hydrated oxide dissolves in aqueous potash, forming a
brown solution.
B. Chromate OF Potash.— a. Monockromaie.'-^L Prepared by either
of the methods given for the preparation of chromic oxide (p. 108).
When this salt is present in solution, together with bichromate of potash
and nitre, the latter salts crystallize out first on the addition of nitric
acid. By the addition of potash, the bichromate may be converted
into the normal salt, and separated from the nitre either by crys-
tallization, or by fusion and the cautious addition of charcoal powder,
till the violent detonation ceases ; the mobile liquid then becomes pasty,
and a small quantity of chromic oxide is separated; the mass is then
exhausted with water, the solution filtered, and left to crystallize. (Tas-
saert.) — 2. By neutralizing commercial bichromate of potash with carbo-
nate of potash. (Thomson; Liebig & Wohler.) — 3. By projecting chromio
oxide into fused chlorate of poti^h. (Liebig & Wbhler, Fogg. 24, 171.)
— The commercial salt frequently contains sulphate of potash. In this
case the solution must be superaaturated with nitric acid and precipitated
by nitrate of baryta. To obtain the commercial salt perfectly pure, it is
freed by recrystallization from silica and alumina, then mixed with nitric
acid, and nitrate of baryta dropped in as long as sulphate of baryta is
precipitated. Chromate of silver is then added to the filtrate as long as
chloride of silver is formed ; after which the solution is filtered, evapo-
rated to dryness, and the residue ignited in a platinum crucible ; lastly
the residue is dissolved in water, and the solution left to ciystaliizc.
(Hayes, SUl. Amer. J. 20, 409.)
Crystalline system the right prismatic; isomorphous with monosulphate
of potash . Fig. 77 ; excepting that the faces between a and t are want-
ing, n : n = 110'' 10'; y : y, hacJeward$ = 120^ 41'; cleavage parallel
to m and t. (Mitscherlich, Fogg, 18, 168.) tt' : w = 72° 34'; a : « =
ISS'' 52'; u : m==126' 17'; y : m=l 19° 43'; y : y, backwards =120° 34';
the faces m and i being the broadest. (Brooke, Ann. Fkil. 22, 120.) — Sp.
gr. = 2-6115 (Thomson), = 2*6402 (Karsten), = 2,705 (Kopp). Lemon-
yellow ; assumes an aurora-red tint whenever it is heated. Up to 204°,
CHROMATE OP POTASH. 145
it undergoes no further change. Fuses at a red heat, previous to which it
decrepitates violentlj. According to Berzelius, it emits a green light
during fusion^ and^ according to Magnus^ crystallizes as it solidifies on
cooling. Has an alkaline reaction, and a cooling, persistently bitter and
metallic taste. Permanent in the air.
Qyiiallued,
KG 47-2 .... 47-58
CrO» 520 .... 52-42
Tasaaert.
Thomson.
40 »„m
«... 4S
52 ....
• >.. o£
KG, CrO» 99-2 .... 100-00 100 ........ 100
When i^ited alone it is not decomposed. Bj strong ignition with char-
coal, it IS resolved into carbonate of potash and chromic oxide. (Moser.)
— It is likewise partially decomposed bj ignition in a current of carbonic
oxide, sesquioxide of chromium being separated. (Gobel.) — Charcoal,
cotton wool, and other organic substances, bum with greater rapidity
when saturated with its solution and dried. ^Jacobson.) — When ignited
with sulphur, it is resolved into chromic oxide, sulphate of potash, and
sulphide of potassium. (Lassaigne.) Probably in the following manner :
8(KG, CrG^ + 20S = 5(KG, SO^) + 3KS» + 4CiaG».
According to Ddppinff, however, if the mixture be gently heated, hypo-
sulphite of potash is likewise formed at the beginning of the action, but
is again partially decomposed by the heat evolved, in consequence of the
combination of the oxygen of the chromic acid with the sulphur.
An aqueous solution of the salt, when heated with pentasulphide of
potassium, yields a gelatinous precipitate of hydratea chromic oxide,
together with hyposulphite of potash and free potash. (Dopping, Ann.
Fharm. 4C, 172.)
8(KG, CrO») + 2KS» = 5(KG, S^OS) + 5KG + 4080'.
With arsenious acid (or an arscnite) the solution gradually forms a
green liquid, (Cooper, Ann. Phil. 20, 77), which solidifies after some
minutes to a stiff jelly; but if the potash salt be added to the arsenious
solution, a green colour is produced without precipitation. (Schweitzer,
J. pr. Chem. 39, 267.) Sulphurous acid passed through the aqueous
solution, precipitates brown hydrated oxide of chromium, which, how-
ever, gradually turns green, and then dissolves completely, forming a
green solution containing potash, chromic oxide, sulphuric acid, hypo-
sulphuric acid, and sulphurous acid. When boiled, it evolves sulphurous
acid, and deposits the whole of the chromium in the form of basic sul-
phite of chromic oxide. (Berthier, N. Ann. Chim. Phys. 7, 77.) By
heating with acetic acid and alcohol, the salt is partially converted into
acetate of potash and acetate of chromic oxide. (Tassaert.) It gives up
the whole of its chromic acid to baryta-water. (Dbbereiner.) To many
acids, as the sulphuric, hydrochloric, nitric, and acetic, it gives up half of
its potash, and is thereby converted into bichromate, which separates
after slight concentration. (Tassaert.^ A solution of the salt m hot
hydrochloric acid, deposits crystals or chloride of potassium on cooling;
a solution in a hot mixture of hydrochloric and sulphuric acid yields
chrome-alum. (Marchand, Pogg. 45, 594.)
Chromate of potash dissolves, according to Thomson, in 2*07 parts of
water at 15*5° (60® P.); according to Moser, in 1*75 parts at 17'5°, and
in 1*67 parts at lOO**. When the salt is dissolved in 2 parts of water, the
VOL. IV. L
146 CHROMIUM^
temperature faWs about 10^. A solution of one part of salt in 2 parts of
water^ has a specific gravity of 1*28; in 3 parts of water, 1*21; in 4
parts, l'18j in 5 parts, 1*15; in 6 parts, 1*12; in 7 parts, I'll; and in 8
f»arts, I'lO. (Moser.) Sp. gr. oi a saturated solution at 8° = 1*368.
Anthon.) One part of the salt imparts a distinct yellow colour to 40,000
parts of water; it likewise imparts to 20 parts of nitre a fine lemon-yellow
colour, when the salts are allowed to crystallize together. (Thomson.)
Chromate of potash is insoluble in alcohol, which precipitates it also from
an aqueous solution. According to Thomson, tincture of galls precipitates
the solution brown.
When chromic acid is mixed with potash in such proportions that the
aqueous solution is neither acid nor alkaline, and the mixture evaporated,
bichromate of potash, having an acid reaction, crystallizes out first, and
then the monochromate, which exhibits an alkaline reaction. (Tassaert.)
b. BicIiromcUe. — When a solution of a is mixed with nitric acid, the
salt b crystallizes out either immediately or aftor evaporation. The
crystals are separated mechanically from those of nitre, and purified by
recrystallization. (Tassaert.) Large, bright-red, rectangular, four-sided
tables and prisms--or when more rapidly crystallized — thinner laminss;
its powder is reddish yellow. Sp. gr. = 198, (Thomson), = 2 6027
(Karsten.) Decrepitates in the fire; fuses at a heat considerably below
redness, and much more readily than a, forming a transparent red liquid;
on cooling it solidifies again in the form of a red fibrous mass, wnich
falls to pieces spontaneously. (ThomsoA.) When slowly cooled after
fusion, it yields fine large crystals, which have the same form as those
obtained from an aaneous solution, but on further cooling, crumble to
powder. (Mitscherlich, Po^g. 28, 120.) The salt has a cooling, bitter,
and metallic taste, reddens litmns, and is permanent in the air. (Thomson.)
Tassaert. Thomson. Grouvelle.
CryMtdUised, Ignited.
KO 47*2 .... 31*22 326 .... 31*579 .... 31*154
2CrO» 104*0 .... 68*78 67*4 .... 68*421 .... 68*8 46
KO,2CrO» 151-2 .... 100*00 1000 .... 100000 .... 100000
At a white heat, half the chromic acid is decomposed, yielding oxy-
fen^ gas and chromic oxide, while monochromate of potash remains
ehind. (Grouvelle.) Detonates slightly with charcoal. Three parts of
bichromate of potash gently heated with 4 parts of oil of vitriol, are
resolved into sulphate of chromic oxide and potash, together with water
and oxygen gas. In this manner oxygen may be prepared pure, and
more cheaply than from chlorate of potash. (Balmain, Fhil. Mag. J. 21,
42; also II., 22.)
KO,2CrO»+4(HO,SO«) = (KO,SO»+Cr«O»,3S03) + 4HO + 3O.
Hydrosulphurio acid gas passed through an aqueous solution of bichro-
mate of potash, precipitates chromic oxide mixed with sulphur. (Hayes.)
Sulphurous acid gas passed through the solution colours it green witnout
precinitation, sulphate and hyposulphate of chromic oxide being pro-
duced. (Berthier.) A current of nitric oxide decomposes it, throwing down
brown chromic oxide, or, after a while, metallic chromium, (p. 1 14.) From
a solution of the salt in boiling hydrochloric acid, chromate of chloride of
potassium crystallizes out as the liquid cools. (Peligot.) The salt dis-
Bolves in water with slight reduction of temperature. (H. Kose.) It
SULPHATE OF CHROMIC OXIDE AND POTASH. 14?
dissolyes in 9*6 parts of water at 17*2 (Thomson), and in 10 parts at
18*7^. ^Moser.) The solution has a deep orange-yellow colour. Accord-
ing to Anthon, a solution saturated at 8^ has a specific gravity of 1*065.
The salt is insoluble in alcohol.
According to Graham, there exists also a Terchromate ofFotcuh.
C. Carbonate of Chromic Oxidb and Potash. — Carbonate of
chromic oxide dissolves sparinffly in aqueous solution of carbonate of
potash, fonninga pale greenish-blue solution and separating again after
long boiling. When sesqnichloride of chromium is supersaturated with
a concentrated solution of carbonate of potash, scarcely any of the pre-
cipitate is redissolved; solution takes place only on mixing more dilute
solutions. The solution of hydrated carbonate of chromic oxide in boiliug
bicarbonate of potash deposits double carbonate of chromic oxide and
potash in pale green crvstalline scales as it cools ; a solution in mono-
carbonate of potash yields a pulverulent double salt on evaporation.
(Berlin.)
IT D. Ptrophosphate op Chromic Oxide and Potash. — Known
only in solution. The liquid exactly resembles sulphate of nickel in
colour, and is not affected either by hydrosulphuric acid, or by hydrosul-
phate of ammonia. (Persoz, Ann, Pharm, 65, 103.) IT
E. Terstdpkide of Chromium with Sulphide of Potassium? — An
aqueous solution of chromate of potash, saturated with hydrosulphuric
acid, becomes dark brown and opaque, and yields a greyish-men precipi-
tate of sesquisulphide of chromium. The filtrate deposits brown tersul-
phide of chromium on exposure to the air, and likewise on the addition
of acids; but the. precipitate is rapidly decomposed even in the liquid itself.
When digested in the air, especially in a dilute state, sulphur is deposited,
and chromate of potash formed. (Berzelius, Poffs^* 8, 422.)
IT F. Sulphate of Chromous Oxide and Potash. — Prepared by
bringing protochloride of chromium in contact with a cold saturated
solution of monosulphate of potash, adding alcohol till a slight precipitate
appears, and then leaving the mixture at rest in a closely stoppered bottle
for a week or two. By this process, very distinct blue crystals are
obtained, having the form of rhombic prisms. They rapidly turn green
in the air.
Peligot.
CalcoUtion. (1) (2)
CrO 360 ..« 16-57 .... 166 .... 170
KO 47-2 .... 21-73
2SOa : 800 .... 36-83 .... .... 37*0
6HO 540 .... 24-87
KO, SO» + CrO, SO» + 6Aq 2172 .... 10000
This salt appears to have the same composition as the numerous double
sulphates formed with the oxides of the magnesia group; and, according
to Prevostaye, is isomorphous with the double sulphate of ferrous oxide
and potash. (Peligot.) ^
G. Sulphate of Chromic Oxide and Potash. — KO, SO* + CrH)*,
3S0'. — a. Anhydrous,^-^. Not decompoMle by water.^k solution of
potash-chrome-alnmi converted into the green modification by heat, is
L 2
148 CHROMIUM.
evaporated to the eonsistenoe of syrup ; warmed^ after the addition of oil
of vitriol, to a temperature of 200^ as long as water is evolved ; and the
resulting insoluble salt freed from the unaltered portion and from the
excess of sulphuric acid, by washing with water. Light green powder.
At a temperature below redness, it loses 5*8 per cent, of sulphuric acid,
and at a strong red heat, the whole of the acid which is in combination
with the chromic oxide; whereupon water dissolves out the sulphate of
potash. The salt is decomposed by long boiling in solution of potash,
with separation of green sesquioxide of chromium, which is not dissolved
by hydrochloric acid till after long boiling. Ammonia, water, sulphuric
acid, hydrochloric acid, and nitric acid, neither decompose nor dissolve
this compound, even when boiled with it. (Hertwig, Pogg. 56, 95.)
a. Dried at 100*".
Hertwig.
KO
47-2 .... 16-43
Ci«0»
80*0 .... 27'85
27-325
4SO»
160-0 .... 55-72
55-516
287-2 .... 100-00
fi. DecompoMU hy water, — ^Formed by heating potash-chrome-alnm
between 300^ and 400^ till the water is entirely driven off. Light green.
When boiled for a long time with water (cold water has no action), it is
resolved into solublesulphate of potash and sulphate of chromic oxide (p. 1 26,
c. a.) which remains in the form of an insoluble green powder. (Hertwig.)
h. BihydraUd, — First observed by Fischer. — Prepared by keeping
potash-chrome-alum at a temperature of 200^ as long as it continues to
lose water; the quantity expelled amounts to 39*522 per cent. -=22 atoms.
The residue is a dark green porous mass. It is decomposed by warm aqueous
ammonia, which separates a dark green oxide soluble in boiling hydro^
chloric acid. It dissolves when boiled for a long time with water, more
rapidly, however, if hydrochloric acid is added. Water and dilute sul-
phuric or hydrochloric acid do not act on the double salt at ordinary tem-
peratures, at least in the course of several days. (Hertwig.)
c. With 24 atoms of water, — Potash-chrome-alum. — First obtained by
Mussin-Pouschkin. {Crell, Ann, 1801, 2, 267.) — l. An aqueous solution
of the blue crystallized tersulphate of chromic oxide and sulphate of
potash, is mixed with sulphuric acid and left to evaporate spontaneously.
(Berzelius.) — 2. Through an aqueous solution of one atom of bichromate
of potash and one atom of oil of vitriol, sulphurous acid gas is passed as
long as it continues to be absorbed, the vessel containing the mixture
being artificially cooled, to prevent the liquid from becoming too much
heated:
KO,2CrO« + SO» + 3SO« = K0,S0» + Ci«0»,3S0".
(Schrotter, Pogg. 53, 326.) — 3. One part of oil of vitriol is added to
3 parts of a saturated aqueous solution of monochromate of potash, and,
after the bichromate of potash which separates is redissolved, 2 parts of
alcohol are added by small portions at a time, so as to prevent too great
a rise of temperature. The mixture after some time assumes a green
colour and deposits crystals of chrome-alum. These crystals are re-
dissolved in a fresh quantity of water, and the solution poured into
shallow dishes and left to evaporate spontaneously. The crystals thus
obtained are dried between blotting paper, and freed from sulphate of
chromic oxide and bisulphate of potash by washing them with a small
quantity of cold water^ till the liquid wmch runs off is no longer green
SULPHATE OP CHROMIC OXIDE AND POTASH. 149
but violet. (Tiaoher, JKastn, Arch. 14,164', 16,212.) By using strong oil of
vitriol a large proportion of the chromic oxide is converted into the
green modification, which does not yield any chrome-alum : with dilute
sulphuric acid, on the contrary, the decomposition takes place slowly,
and without perceptible rise of temperature, and the whole of the chromic
oxide crystallizes out as alum. (Berzelius.) IT Traube, (Ann. Fkarm.
66, 165), gives the following improved method. One part of bichromate
of potash is dissolved in 2 parts of sulphuric acid diluted with a quan-
tity of water sufficient to prevent the solution from depositing crystals at
ordinary temperatures ; the whole is then gradually added to a quan-
tity of alcohol contained in a vessel which is surrounded with cold
water, to prevent too great a rise of temperature. A considerable portion
of the chrome-alum is at once precipitated in the form of a crystalline
meal. The mother-liquid is then mixed with -f of its weight of nitric acid,
to prevent the formation of the green modification ; evaporated in a water
bath to i its weight ; and lastly treated with an equal weight of alcohol,
and set aside to crystallize. The greater part of the remaining chrome-
alum separates in crystals, which are purified by recrystallization from a
solution in water heated to 50^ IT
Chrome-alum forms regular octohedrons of a violet-red colour, ruby-
red by transmitted light; it is permanent in the air. When impure,
however, it effloresces on the surface, assuming a green colour if it con-
tains excess of chromic sulphate, and a violet colour if the sulphate of
potash predominates. (Fischer.)
Calculation. Fischer.
KG 47-2 .... 9-38 .... 9*52
Ci«0» 800 .... 15-90 .... 15-60
4SO» 1600 .... 31-80 .... 32-27
24HO 216-0 .... 42-92 .... 42-60
KO,SO3 + Ci«0»,3S0» + 24Aq 503-2 .... 10000 Z. 99*99
IT According to Jacquelain (Compt, rend. 24, 439) chrome-alum con-
tains only 22 atoms of water. IT
When heated, it fuses, gives off its water of crystallization, and is
converted into the grass-green coloured salt 6 (Fischer), and at a tempe-
rature between 300° and 400% into the salt a, (Hertwig); lastly, it is
converted by ignition into a powder which is lilac-coloured while hot,
and yellowifih-green when cold. This powder is perfectly insoluble in
boiling water and in all acids, except oil of vitriol, which dissolves it in
very small quantity, and deposits it again for the most part on cooling,
or completely on the addition of water. (Fischer.) [This is probably
the salt a, aA
Chrome-atum is soluble in 6 parts of cold water; the violet solution
suffers the alum to crystallize out unchanged by spontaneous evaporation;
but if heated to between 50° and 75°, it turns green, and according to the
extent of decomposition, either deposits, on evaporation, a brilliant green,
amorphous, difficultly soluble mass, or yields crystals of sulphate of
potash, leaving green sulphate of chromic oxide in solution. (Fischer.)
The sulphate of potash separates only from a highly concentrated solution,
and in small quantity. (Schrbtter.) A solution which has been turned
green by boiling, becomes blue again after long standing, and when eva-
porated yields crystals of chrome-alum, with which a small quantity of
the green salt still remains mixed. By re-solution and standing, the
latter is also converted into chrome-alum. These changes are similar to
1
150 CHBOMIVM.
tlioBe exhibited bj blae and green sulphate of chromic oxide. ^ Chrome-
alum contains the bine sulphate; a solution of chrome-alum introduced
into a ghias tube, and coyered witb a stratum of alcohol, likewise yields
a result similar to that described on page 127. (Schrbtter.)
H. Sulphate op Potash with Chrom ate op Potash. — o. — With
Monochromate of Potash, — Sent into the market by French manufacturers
instead of the pure roonosulphate. It crystallizes in pale yellow, four and
six-sided prisms, with four or six-sided summits; has a bitter taste; and
decrepitates on ignited charcoal. Contains 43*3 per cent, of chromate,
and 56'7 of sulphate of potash. With nitrate of baryta it gives a pre-
cipitate, which dissolves but partially in nitric acid, sulphate of baryta
being left behind. Dissolves with great focility both in cold and in not
water; from the latter solution it crystallizes on cooling. (Boutron-
Charlard, J. Pharm. 9, 184.)
h. With Bichromate of Potash. — If in the preparation of chromic acid
by Fritzsche's method (p. 117) a slight excess of chromate of potash
is used, and the precipitated red acid is dissolved in a small quantity of
cold water, a yellow salt remains, which crystallizes from a solution in
warm water, in broad rhombic needles, united together in stellated
masses. The salt is of a yellowish-red colour, somewhat lighter than
that of bichromate of potash, which it resembles in taste. When heated
it becomes deep red, loses a small quantity of water, and then fuses to a
dark brown liquid, solidifying, as it cools, in a metallic-looking mass,
which assumes a liver-colour in the air. (Reinsch, J, pr, Chem, 28, 371.)
Calculation. Reinsch.
2KO 94-4 .... 39-60
2CrO« 1040 .... 43-62 3864
SO> 400 .... 16-78 16-21
KO,SO» + KO,2CrO».... 238-4 .... 10000
I. Chromate of Chloride of Potassium. — 1. An aqueous solution
of bichromate of potash is boiled for a short time with excess of hydro-
chloric acid and left to crystallise by cooling :
KO, 2CrO« + HCl - KCl, 2CrO« + HO.
If the boiling be too long continued, the chromic acid and the excess of
hydrochloric acid re-act upon each other in such a manner as to yield
chromic oxide and chlorine.— •2. An aqueous solution of one atom of
chloride of potassium acidulated with hydrochloric acid, is added to an
aqueous solution of 2 atoms of chromic acid. — 3. Chromate of chloride of
chromium is treated with a saturated solution of chloride of potassium :
3KC1 + 2(CrCls,2CrO») + 6H0 = 3(KC1, 2Cp03) + 6HC1.
The crystals are dried between folds of blotting paper.
The salt forms right rectangular prisms which have the same colour
as bichromate of potash, and are transparent and permanent in the air.
When treated with oil of vitriol, it evolves terohloride of chromium; [or
rather chlorochromic acid;] probably thus :
3(KC1, 2CrO^ + 12S0» = 3(K0.S0») + Cra»,2CrO« + 3(CrO«,3SO»).
The salt becomes white and opaque in pure water, and dissolves, forming
« solution, whichi when evaporated^ either spontaneously or with the aid
CHROMATE OF SODA. 151
of heat, deposits crystals of bichromate of potash, hydrochloric acid being
set free; but from a solution in water containing hydrochloric acid, the
chromate of chloride of potassium crystallizes out undecomposed. If the
water contains only a small quantity of hydrochloric acid, bichromate of
potash separates at the same time with the chromate of chloride of
potassium; with too much hydrochloric acid, a portion of the chromic
acid is converted into chromic oxide. (Pelouze, Ann, Chim. Phys, 52,
267.)
Calculation. Pdotize.
K 39-2 .... 21-95 21-88
a 35-4 .... 19-82 19-41
2CrQ» 1040 .... 58-23 58-21
KCl,2CrO» 178-6 .... 100*00 ~.. 99 50
K. Sesquifluoridb of Chromium +F]:inoBiDB of Potassium.—
Green powder, very difficultly soluble in water. (Berzelius.)
L. Bidiromaie of Potash -\-Nitraie of Potash^ — The yellow solution
of bichromate of potash in nitric acid turns dark brownish-red when
boiled, but becomes somewhat paler again on cooling, and, after the
greater part of the nitric acid has been evaporated, leaves a thick, black,
uncrystailizable liq^uid; when further heated, it continues to evolve strong
nitric acid, then solidifies, gives off hyponitric acid gas, and is recon-
verted into bichromate of potasL (Reinsch.)
Chromium and Sodium.
A. Chromitb of Soda. — Similar to the potash compound. — On pli^
tinum, chromic oxide forms with carbonate of soda in the inner blowpipe
flame, an opaque glass, which appears green when cold. In the outer
flame, a dark yellowish-brown glass is obtained, which becomes yellow
and opaque on cooling.
B. Chromatb of Soda. — a. Monochromate. — 1. Formed by igniting
chrome-iron ore with half its weight of hydrate of soda and a small
quantity of nitrate of soda, exhausting the fused mass with water, and
leaving the solution to crystallize. (Moser.) — 2. By neutralizing chromic
acid with carbonate of soda. (Moser.) — 3. By igniting one part of chromic
oxide with 2 parts of nitrate of soda, digesting the mass in water, filtering
the solution, and evaporating to the crystallizing point. ^Kopp.^ The
salt belongs to the oblique prismatic system of crystallization. Fig. 118,
but without any distinct plane of cleavage; i: t=- 107° 43'; u : u^ =:
80'»4'; u :t = lSO° 8'; i :u=:10V 16'; t :a = 133°20'; t : A=100°
20'. (Brooke, Ann, PhU, 22, 287.) it is isomorphous with sulphate of
soda. Lemon-yellow ; transparent ; has an alkaline reaction and rough
metallic taste. (John, Moser.) The crystals eflloresce very rapidly
(Brooke); they are permanent in the air, and become somewhat moist in
a damp atmosphere only. (Moser.) They melt even with the heat of the
hand; become opaque in alcohol from loss of their water of crystallization,
and deliquesce rapidly in the air. (Kopp, Ann. Pharm, 42, 99.) They
dissolve readily in water and sparingly in alcohol. (John, Moser.) An
aqueous solution evaporated at a temperature above 30"^, deposits the salt
in the anhydrous state. (Kopp.)
152 CHROMIUM.
Cry9iaUizid, Kopp.
NaO 31-2 .... 1801 \ .^ ..
CrO» 520 .... 3002 j ^^ *^
lOHO 900 .... 51-97 53-55
NaO,CrO» + 10Aq 1732 .... 10000 ZZ 100*00
5. Bichromate. — Crystallizes in thin, hyacinth-red^ six-sided prisms,
bevilled at the extremities; it is more soluble than a, and consequently
crystallizes out after it. (Moser.)
When a salt of chromic oxide is supersatnrated with monocarbonate
or bicarbonate of soda^ the precipitated carbonate of chromic oxide is
perfectly insoluble in excess of the re-agent.
C. Chromic oxide dissolves slowly in borax, and imparts to it in the
inner blowpipe flame, an emerald-green colour, which increases in bril-
liancy on cooling ; in the outer flame on platinum, the green colour is
almost entirely converted into yellowish-brown, so that a mere tinge of
the original colour is observable on cooling. (Berzelius.)
D. Chromic oxide dissolves in mtcrocosmic salt, yielding a green
glass, both in the inner and outer blowpipe flame. If an excess of the
sesquioxide is added, the glass swells up every time it is cooled after
ignition, and presents a frothy appearance, arising from an evolution of
gas not yet explained; this takes place whether the fusion is effected in
the outer or in the inner flame, on platinum or on charcoal. (Berzelius.)
E. Sulphate of Chromic Oxide and Soda. — Soda-chronM^Llum,^^
A mixture of 2 parts (1 atom) of bichromate of soda and 3 parts (4
atoms) of oil of vitriol treated gradually with alcohol, so that its tempe-
rature may not rise too high, evolves aldehyde with violent effervescence,
and deposits the alum, after long standing, in rounded masses, consisting
of NaO, SO»+Cr»0', 3SO» + 24Aq. This salt cannot be obtained in dis-
tinct crystals. At a temperature of 100®, the mass loses 16 atoms of
water. It effloresces in tne air more' rapidly than ammonia or potash-
chrome-alum, and its solution possesses the same characters as the solu-
tions of these salts. (Schrbtter.)
F. Chromate of Chloride of Sodium. — Deliquescent (Pelouze.)
0. Sesquifluoride of Chromium -h Fluoride of Sodium.— Green
powder, very sparingly soluble in water. (Berzelius.)
H. Chromate op Soda and Potash. — ^When the white porcelain-
like mass obtained by fusing together 2 parts of bichromate of potash and
1 part of carbonate of soda, is dissolved in boiling water, it emits light on
cooling (I. 208.), and deposits yellow crystals which have the form of
sulphate of potash, and, like the latter, decrepitate when heated. The
salt contains 36'd9 per cent, of potash, 8*40 of soda, and 54*40 of
chromic acid, 2(K0, CrO*) -h NaO, CrO'. (H. Rose, Pogg, 52, 585.)
1. Sulphocbromatb of Soda and Potash. — Monochromate of
potash and monosulphate of soda fused together in equivalent proportions,
yield, when rapidfy cooled, a fissured friable mass, wnich, on cooling from
CHROMATE OF LIME. 15S
a boiling fiolation in water, is deposited, with yiyid phosphorescence, in
yellow crystals having the form of sulphate of potash ; thej decrepitate
in the fire. These crystals are composed of 41*92 per cent, of potash,
9-21 of soda, 3*11 of chromic acid, and 45*62 ot sulphuric acid. (H.
Bose.)
Chbomium and Lithium.
Chromate of LiTHiA.*^Cry8tal]izes in orange-yellow, oblique rhombic
prisms, or in dendritic masses. It is readily soluble in water. (C. G.
umelin.)
Chromiitm Asn Babium.
GnROMATEOF Baryta. — Prepared by precipitating chromate of
potash with chloride of barium or baryta-water. Baryta-salts are pre-
cipitated by chromate of potash at the same degree of dilution as by the
sulphate. (J. D. Smith, Fkil, Mag. J. 8, 260.) This compound forms a
lemon-yellow powder, the colour of which, according to Moser, is ren-
dered darker by prolonged ignition. It is not decomposed by cold sul-
phuric acid, and with difficulty by the same acid when hot. Aqueous solu-
tions of the alkaline sulphates also do not affect it, even with the aid of
heat, or but slightly. (Fischer, Kastn, Arch. 9, 356.) It is insoluble in
water, but dissolves easily in nitric acid, hydrochloric acid, or excess of
chromic acid, forming a reddish-yellow solution of bichromate of baryta;
from this solution it is again precipitated by ammonia.
Calcoladon. Beraelioj. Vauquelm.
BaO 76*6 .... 59*57 59*85 .... 57*75
CrO» 520 .... 40*43 40*15 .... 42*25
BaO,CrO» 128*6 .... 100-00 10000 .... 100*00
Chromium and Strontium.
Chromatb of Strontia. — Formed by precipitating chromate of
potash with chloride of strontium. Dilute solutions yield no precipitate.
(J. D. Smith). Strontia-water does not affect chromate of potash. (Dobe-
reincr.) Chromate of strontia is a pale yellow powder, very slightly soluble
in water, but readily soluble in hydrochloric, nitric, and chromic acids.
Chromium and Calcium.
A. Chromatb of Limb. — Monochromate of potash gives with chlo-
ride of calcium, a pale yellow precipitate which slowly subsides.
(Thomson, Moser.) Carbonate of lime decomposes chromate of potash
but partially, forming chromate of lime. (Kuhlmann, Ann, Pharm. 41,
229.) Lime-water does not precipitate chromate of potash. The
yellowish-brown silky scales, very soluble in water, which Yauquelin
obtained by dissolving lime in aqueous chromic acid, are regarded by
Moser as an acid salt. *
154 CHROMIUM.
B. Chromatb of Ghlobioe of Calcium. — CaCl^ 2CrO'. — Deliques-
cent. (Pelouze.)
IT C. Chromatb of Limb and Potash. — KO, CrO'+CaO, CrO*
+ 2 HO. — Prepared bj saturating a solution of bichromate of potash
with hydrate of lime, and passing carbonic acid through the clear liquid,
evaporated at a temperature between 30^ and 40^. When ignited it
fuses, without decomposition. (Schweitzer, J, pr. Ch^m. 39,269.) IT
Chromium and Magnesium.
IT A. Chromite of Magnesia. — Obtained, mixed with magnesia, by
decomposing the double chromate of magnesia and potash at a low red
heat. The magnesia may be afterwards remored by a dillite acid. It has
« fine brown colour, ana is insoluble in acids and alkalis; its formula
is MgO, C^»0^ (Schweitier.) IT
B. Chromatb of Magnesia.— Prepared by dissolvinff magnesia in
chromic acid. Crystallizes in large transparent, orange-yellow, six-sided
prisms, which dissolve readily in water. (Vauquelin.^ The crystals are
lemon yellow, and have the same form as those of sulphate of magnesia;
at 15% their specific gravity is 1*66. (Kopp.)
Ankjfdraui, Cry9tallized. Kopp.
Mg:0 20 .... 27-78 MgO 20 .... 1481 1 ,«.«.
CrO* 52 .... 72-22 CrO« 52 .... 38-52/ "" ^^^^
^^^ 7HO 63 .... 46-67 .... 47*15
Mg0,Cr03 72 ....100-00 +7Aq 135 ....10000 .... lOO'OO
C. Chromatb op Chloridb of Magnesium. — MgCl, 2CrO^■— Deli-
quescent. (Pelouze.)
IT D. Chromate op Magnesia and Potash. — KO, CrO* + MgO,
CrO' -I- 2H0. — A moderately concentrated solution of bichromate of
potash is digested with magnesia alba, and the clear liquid evaporated to
the crystallizing point. Beautiful yellow crystals belonging to the oblique
prismatic system, and resembling those of gypsum. When heated it
becomes orange yellow, and fuses at incipient redness, evolving oxygen
and leaving theoompound A. (Anthon, Buchner'a ReperU 34, 248, Schweit-
zer.) IT
Chromium and Cerium.
Chromate of Cerous Oxide. — a, Monochromate. — Carbonate of
oerons oxide dissolves freely in aqueous chromic acid; the solution is
yellow, has a rough taste, and after some time deposits monochromate of
oerous oxide, in the form of a yellow powder. (John.)— 6. BichroTncUe,'-^
The solution from which the normal salt is deposited, yields, on evapo-
ration, small reddish crystals surrounded by an amorphous salt. (John.)
The salt crystaUixes in sinall, red, transparent prisms, soluble in water.
(Berzelius.)
CHROMATB 07 SILICA. 155
Chromium and Yttrium.
Chromatb op Yttria.— a. Basic chromate. — Aqneoas chromic acid
saturated with carbonate of yttria, forms a brown solution, which, after
some time, deposits the basic salt in the form of a brown powder; on
boiling the liquid, an additional quantity is thrown down, of a some*
what lighter colour, while monochromate of yttria remains in solution.
(Berlin.)
b. Mono€hromat€,''^Bj evaporating the solution of carbonate of
yttria in aqueous chromic acid, orange yellow dendritic crystals are
obtained, which are neutral towards vegetable colours, of a rough and
Sungent taste, and readily soluble in water. (John.) The solution
ocanted from the salt a, yields by spontaneous evaporation, sometimes
yellowish-brown, deliquescent, acicular crystals, and sometimes a brown
amorphous residue. (Berlin.)
Chromium and Glucinum.
Chromate op Glucina. — a, MonochromaU. — A yellow salt insoluble
in water. — 6, Acid chromate. — The yellow solution yields a gummy
uncrystallizable residue. (John, Berzelius.)
Chromium and Aluminum.
Chromate op Alumina.*—^. Batic chromaU,-^K solution of h
mixed with monochromate of potash, converts the latter into bichromate,
and deposits a basic salt, which, however, by Ion? continued washing, is
completely resolved into hydrate of alumina and the salt 6, which dis-
solves. (Maus.)
h. Acid chramaie.'-^Bj saturating aqueous chromic acid with hydrate
of alumina and evaporating the solution, a homy mass is obtained, which
in its chemical relations, resembles the quadrochromate of ferric oxide,
and probably, therefore, has a similar composition : APO'^ 4CrO'.
(Maus, Poy^. 11,81.)
Chromium and Thorinum.
Chromate op Thorina.-— Prepared by double decomposition: It
forms a pale yellow flocculent precipitate, which dissolves in excess of
chromic acid, yielding an acid salt. (Berzelius.)
Chromium and Silicium.
A. Chromate of Silica f-^ According to Godon, when an aqueous
solution of chromic acid is evaporated with hydrate of silica, a reddish-
yellow insoluble powder is formed, which sustains the heat of a pottery
furnace without decomposition. According to Quesneville, (J, Pharm,
16, 131; also IT. Tr. 22, 1, 254), chromic acid dissolves a small quantity
of hydrated silica, and again deposits it on evaporation; the precipitated
silica may be freed from every trace of chromic acid by washing.
156 CHROMIUM.
B. Fluoride of Silicium and Chromium^ and Hydrofiuate of Silica
and Chromic Oxide.~^A solution of chromic oxide in hydrofluosilicio acid
yields on eyaporation, a transparent green, amorphoas mass which deli-
Soesces in the air, and, when it contains an excess of acid, swells np in
be fire like alum, and again deliquesces if afterwards exposed to the air.
(Berzelius, Fo^^. 1, 201.)
C. Ghromate of potash fuses with glass, and forms a transparent,
emerald-green glass. Chromic oxide does not dissolye in glass, but merely
renders it turbid. (Nasse.)
Chromium and Tungsten.
TuNGSTATE OF Chromig Oxide. — Green precipitate.
A solution of sulphotungstate of potassium gives with a chromic salt,
a scanty greenish-brown precipitate; hence the compound of tersulphide
of tungsten with sesquisulphide of chromium dissolves in water with toler-
able facility. (Berzeuus.)
Chromium and Molybdenum.
Chromate of potash added to a solution of protochloride of molyb-
denum, precipitates basic chromate of molybdic oxide, sesquichloride of
chromium remaining dissolved in the liquid. (Berzelius.)
A. Chromate of Moltbdic Oxide. — a. Baric chromate, — Precipi-
tated from h or c, by the addition of ammonia, in ffreyish-yellow flakes^
insoluble in water.— -6. Bichromate.'^The pale yellow aqueous solution
yields by roontaneous evaporation, white or light yellow crystalline
scales, or efflorescent needles; the salt when perfectly dry is white.—
c. Add cAromottf.— The brown aqueous solution dries up to a brown un-
crystallizable mass, which has an effloresced, saline appearance, and redis-
solves in water without alteration. (Berzelius.)
B. Chromate of Moltbdic Acid.— Aqueous chromic acid dissolves
molybdic acid at a boiling heat, forming a yellow solution, which if the
molybdic acid is In excess, solidifies to a yellow transparent jelly. The
filtered solution yields on evaporation, a transparent, yellowish-brown,
uncrystalHzable varnish. Water resolves the latter into a brown sub-
stance which immediately dissolves, and a pale yellow powder like-
wise soluble in a larger quantity of water. (Berzelius, Fo^g. 6, 384.)
C. Molybdate of Chromic Oxide. — Molybdate of ammonia gives
with sesquichloride of chromium, an apple-green precipitate (Moser),
soluble in excess of the molybdate of ammonia. (Berzelius.)
D. Sulphomolybdatb of Chromium. — Cr»S', SMoS*. — Sulphomolyb-
date of potassium gives with chromic salts a dark brown precipitate,
which assumes a greenish tinge after drying.
E. Persulphomolybdate op Chromium. — Cr'S*, 3MoS*. — Persul-
phomolybdate of potassium gives a dark red precipitate with salts of
chromic oxide. (Berzelius.)
URANIUM. 157
Chromiitm and Vanadium.
Chromatb of Vanadic Oxide. — The brownisb-yellow solution of
hydrated vanadic oxide in aqaeous chromic acid leaves when evaporated,
a brilliant dark brown varnish, which dissolves but partially in water,
forming a yellow solution, from which sulphuretted hydrogen throws
down a pale green precipitate. (Berzelius.)
OtAo' Camhinatians* With iron.
Chapter XXII.
URANIUM.
Klaproth. Beitrage, 2, 197; also Crell. Ann. 1789, 2,387.
Richter. Regulus of Uranium. N. Oegenst, d. Chem, 1, 1 ; 9, 36.— Uranic
Oxide. A. Gehl. 4, 402.
Bucholz. Beitrage, 1, 62; A. Gehl. 4, 17 & 134.
Lecanu et Serbat. J, Fharm, 9, 141 ; also Schw, 44, 35.
Laogier. J. Pharm, 9, 145; also Schw. 44, 40.
Lecanu. J. Fharm. 11, 279.
Laugier & Boudet. J. Fharm. 11, 286.
Arfvedson. Fogg. 1, 245; also Schw. 44, 8.
Berzelius. Fogg. 1, 359; also Sdm. 44, 191. — Jahrtiber. 22, 116.
Brande. QwiH. J. of Sc. 14, 86 ; also Schw. 44, 1.
Peligot. Compt rend. 1841, 735; alsoJ. pr. Chem. 23, 494. — J, Fharm.
27, 525; also Ann, Fharm. 41, 141; also J. pr. Chem. 24, 442.—
i\r. Ann. Chim. Fhyt. 5,5; also Ann. Fharm. 43, 255 ; also i^T. Ann.
Chim. Fhy$. 12, 258.
Ebelmen. N. Ann. Chim. Fhy$. 5, 189; also Jnn. Pharm. 43, 286; also
J. pr. Chem. 27, 385.
Rammelsberg. Fogg. 55, 318; 5Q, 125; 59, 1.
Wertheim. J. pr. Chem. 29, 209.
Werther. J. pr. Chem. 43, 321; abstr. Ann. Pharm. 68, 312; also
Pharm. Centr. 1848, 433; also Liehig 4e Kopp's Jahresb. 1847—8,
419.
Stnontmes; Uran, Urane.
History. Klaproth, in the year 1789, discovered in Pitchblende and
Uranite a metallic oxide, to the metal of which he gave the name of ura*
nium. Till lately, the protoxide (UO) obtained by exposing the green
158 UBAMUM.
oxide (U' 0') to a white lieat in contact witli charcoal, and also bj other
methods, was regarded as the real metal, and the atomic weight of ura-
nium determined accordingly. But in 1841, Peligot discovered the error
of this view, and accordingly the atomic weight of nranium was reduced
to less than one-third its former amount. Peligot likewise prepared the
pure metal.
Sourcei, In small quantities, as impure uranoso-uranic oxide {Pitch-
blende) ; as hydrated oxide {Uranic oi^re) ; as snlphate of uranous oxide;
as basic sulphate of uranic oxide; as phosphate of uranic oxide and lime;
and as phosphate of uranic oxide and cnpric oxide ( Uranite) ; as tanta-
late of uranous oxide {Uranotantcdite), (G. Rose, Pogg. 48, 555); and in
small quantity in Yttrotantalite, especially in the yellow varieties, and in
Euxenite.
Preparation. 1. A mixture — not exceeding 10 grammes— of one part
of potassium and 2 parts of protochloride of uranium is introduced as
rapidly as possible (to avoid the attraction of atmospheric moisture) into
a small platinum crucible— the cover fastened down by a wire— and the
whole heated over a spirit-lamp. Decomposition then takes place, the
crucible becoming red-hot, and a portion of the mass being projected from
it by the violence of the action. To prevent injury from the burning
potflkssium, it is advisable therefore, before applying the heat, to enclose
the crucible in a larger vessel of the same kind. After the action has
ceased, the crucible is again placed over the lamp, and strongly heated
to volatilize the remaining potassium, and also to fuse the chloride of
TOktassium produced, and thereby facilitate the aggregation of the uranium.
The contents of the crucible, when cool, are treated with cold water.
— whereupon, hydrogen gas is evolved, either by the action of a small
residual quantity of potassium, or—- if the potassium has acted but imper-
fectly — by the action of j-chloride of uranium. The metal is washed with
pure water. (Peligot.) — 2. A solution of uranite of ammonia in hydrochloric
acid is mixed with an excess of sal-ammoniac and about its own wei£;ht
of common salt; the mixture evaporated to dryness; and the residue
ignited in a covered crucible, till the sal-ammoniac is volatilized and the
chloride of sodium fused, whereby access of air is prevented. The mass,
after cooling, is digested in cold water, which removes the common salt
and leaves metallic uranium*. (Wbhler, Ann. Pkarm. 41, 345.) — Clarke |l
obtained from pitchblende and from cupreous uranite, before the oxy- ^
hydrogen blowpipe, a steel-grey metal, scarcely yielding to the hardest
file, and not possessed of magnetic properties.
Propertiei. Sometimes in the form of a black powder, sometimes
welded together on the sides of the crucible in silvery laminsB and fibrous
masses, which yield to the file and appear to be somewhat ductile. (Peligot)
IT According to Benelius, uranium exists in two allotropic states
(corresponding to silicium, &c.). U« is prepared from the chloride by
means of potassium, and is one of the most combustible bodies known ;
it likewise dissolves readily in dilute acids, with evolution of hydrogen.
U0, obtained, according to Richter's method, by reducing uranic oxide
with dried ox-blood at a high temperature, is not acted on by hydrochlo-
ric acid, though it dissolves in aqua-regia ; these modifications may be
traced in the soluble and insoluble forms of uranous oxide (p. 161).
* This process yields the protoxide, not the metal.
URANOUS OXIDE. 159
Atomic weight of Uranium. 59*43 (Ebelmen),— 59*71 (Wertheim),
■60 (Peligot, Rammelsberg), — 64-2 (Berzelius),— 59'7 (Werther).
Compounds of Uranium,
Uranium and Oxtqen.
The metal remains unaltered in the air at ordinary temperatures ; when
slightly heated, it takes fire and burns with a brilliant white light, increas-
ing in bulk and beinfi; converted into uranoso-uranic oxide. — When heated
on paper, it inflames before the latter takes fire; when thrown into the flame
of a candle, it bums with brilliant scintillations. It does not decompose
cold water, but dissolyes in dilute acids, liberating hydrogen gas and form-
ing a solution of uranoos oxide. (Peligot.)
A. Suboxide op Uranium? U*0'.
When an aqueous solution of three-fourths chloride of uranium is
treated with ammonia, a brown precipitate is obtained, which is probably
[the hydrate of] U* 0' ; the precipitate is converted in a few moments^
with evolution of hydrogen gas, into a greenish yellow [hydrated] sub-
oxide, containing a larger proportion of oxygen. The latter by exposure
to the air, is first converted into brown hydrated uranous oxide, and then
into yellow uranic oxide or uranate of ammonia. (Peligot.)
B. Uranous Oxidb. UO.
Protoxide of Uranium, Uranoxydvl,
Formerly mistaken for metallic uranium.
Preparation. 1. By exposing uranoso-uranic oxide mixed with -^ of
its weight of charcoal powder to the strongest heat of a blast-furnace.
(Bucholz.)— Richter used bullock's blood, Klaproth used oil as the
deoxidizing agent. — 2. By igniting oxalate of uranic oxide alone and out
of contact of air. (Berzelius.) — According to Peligot, the protoxide is
obtained in the state of greatest purity by heating oxalate of uranic oxide
to redness in a hard glass tube, in a current of hydrogen gas ; the action
is so violent that the current of hydro^n must be checked for a while, as
otherwise the mass will be projected from the tube. The black oxide,
U^O^, is first formed, and then the brown protoxide, UO. After the
reduction is finished, the tube, still containing hydrogen, is sealed at both
ends. — The protoxide thus obtained is mixed with charcoal, and, when
dissolved in nitric acid, leaves blackish brown fiakes. (Bammelsberg.) —
3. Hydrogen gas, dried by passing over chloride of calcium, is conducted
over finely divided and previously i^ited uranoso-uranic oxide, heated to
redness in a tube of glass or porcelain ; the reduction is accomplished in a
few minutes, the mass becoming red hot. (Arfvedson^ Lecanu.) — If the
uranoso-uranic oxide is dense — as, for instance, when it is obtained by
igniting the nitrate of uranic oxide — it must be frequently agitated in the
tube during the above process, in order to ensure its complete reduction
to the state of protoxide. (Rammelsberg). — 4. By passing hydrogen gas
160 URANIUM.
in the same manner over red-hot chloride of nranous oxide and potassium
i— whereby hydrochloric acid is produced — and removing the chloride of
potassium and undecomposed salt by digestion in water. (Arfvedson.) —
The same result may be obtained by simply igniting the double chloride
of nranous oxide and potassium, or — ^what is the same thing — ^the residue
obtained by eraporating to dryness the solution of uranate of potash in
hydrochloric acid. (Peligot.)
Properties, As prepared by the first method, this oxide is iron-grey
and earthy; and, when examined by the microscope, appears to be com-
posed of small needles, having a faint metallic lustre. (Bncholz.) Spe-
cific gravity =6-44 (Klaproth); 694 (Richter); 9*0 (Bucholz).— Very
refractory (Bucholz.) When prepared by the second method, it forms a
cinnamon-brown powder (Peligot), — a copper-red, crystalline powder with
metallic lustre, and of specific gravity 10*15. ^Ebelmen.) The powder,
when oxidized in the air, and a^ain reduced oy hydrogen gas, appears
dark-red, and destitute of metallic lustre. (Ebelmen.)^When prepared by
the third method, it is a liver-coloured powder (Arfvedson); a black powder
(Laugier, Boudet).^The fourth method yields it in the form of a metallio-
shining powder, which, under the microscope, appears to consist chiefly
of regular octohedrons, having a strong metallic lustre; at the edges,
however, they are slightly translucent, transmitting light of a reddish-
brown colour; they yield a reddish-brown powder. (Arfvedson.) — Crys-
talline scales, having the metallic lustre. (Peligot.)
u
o
Calculatioiii according to Peligot.
60 88-24
8 11-76
uo..
68 100-00
(UO » 802-49 + 100 <= 902-49. BeneUoB.)
That this oxide is not metallic uranium, is proved by the following
facts : — When it is mixed with lamp-black, and strongly ignited in a cur-
rent of hydrogen gas till no more water is produced, the residue does not
contain metallic uranium, but the protoxide ; for on passing chlorine over
it, carbonic acid and carbonic oxide are formed, together with a sub-
limate of protochloride of uranium. When protoxide of uranium, prepared
by the fourth method is ignited in chlorine gas, it likewise yields chloride
of uranium, carbonic acid and carbonic oxide. (Peligot.) — Potassium, at
the temperature at which it sublimes, does not abstract oxygen from
nranous oxide. (Plantamour, J. pr. Chem, 23, 230.) — Hydrochloric acid
§as, passed over ignited uranous oxide, produces no change in it, beyond
estroying its tendency to take fire in the air at ordinary temperatures.
(Peligot.)— Peligot regards uranous oxide, in some of its combinations,
as a compound metal U' 0', which, though it contains oxygen, neverthe-
less plays the part of a simple metal. To distinguish this compound from
pure uranium, Peligot calls it Uran or Uranyl. But though many ura-
nium compounds exhibit peculiarities which seem to favour this view
(vid. Salts of Uranic oxide, ChlofHde of Uranous oxide, and Chloride of
OranoiLs oxide and Potassium), there is at present no absolute neces-
sity for adopting it. [For objections to this theory, see Berzelius, Jahresb.
1843, 114, and Kiihn, Ann, Pharm» 41, 337. On the contrary: Peligot,
iT. Ann. Ckim. Pkys. 12, 549.]
URANOSO-URANIC OXIDE. 161
Combinations.'''^. With Water. Htdratb op Ubanous Oxidb.
Anunonu^ potash^ or soda, added to a salt of uranoas oxide— the hjdro-
chlorate, for example — ^throws down reddish brown, gelatinous flakes^
which, on boiling the liquid, turn black and increase in density, pro-
bably from loss of water. The precipitate, when freed from every trace
of ammonia, remains brown even if exposed to the air ; but, if it be
merely washed with cold water, it still retains ammoni^^ and, on exposure
to the air, is converted into yellow uranate of ammonia. (Peligot)
h. With Acids, forming the Salts of Uranous Oxide, or Uranous
Salts. — Uranous oxide, when obtained b^ ignition, is insoluble in
boiling dilute hydrochloric or sulphuric acid, but dissolves in strong
oil of vitriol. The hydrate is easily soluble in acids. The green
solution, when evaporated, yields green or greenish white salts. Ura-
nous salts in solution are converted into uranic salts : by exposure to the
air, by the action of nitric acid even at ordinary temperatures, and by
gold or silver salts, the action in this case being accompanied by precipi-
tation of metallic gold or silver. The alkalis, and even carbonate of lime,
precipitate from these salts a reddish brown, gelatinous hydrate of uranous
oxide. Alkaline carbonates, added to solutions of uranous salts, give off
carbonic acid, and throw down a green precipitate, which, when washed
aiid dried, consists of pure hydrated uranous oxide. This precipitate
is soluble in excess of the reagent, especially in carbonate of ammonia,
and forms a green solution. (Rammelsberg.)
C. Black Uranoso-uranio Oxide. U^O".
The residue obtained by strongly igniting green uranoso-uranic oxide
or nitrate of uranic oxide. To prevent it reabsorbing oxygen as it cools,
and passing again to the state of green oxide, the red-hot crucible must
be closely covered and placed upon a thick metallic plate, so that it may
cool rapidly. When this oxide is ignited in a current of hydrogen gas,
it gives up 3 per cent, of oxygen, and is reduced to the state of ura-
nous oxide. [U*0«— 0=4U0; 280 : 8 = 100 : 2-86.1 It dissolves in
acids, forming a mixture of uranous and uranic salts, (religot) Ebelmen
regards this oxide as a mere mixture of UO and U'O^— -According to
Rammelsberg's experiments also {Pogg. 59, 5), the existence of a distinct
black uranoso-uranic oxide is a matter of doubt. The uranoso-uranic
oxide obtained by strongly igniting nitrate of uranic oxide, increajBcd in
weight by gentle ignition in the air, sometimes to the amount of 0*04 per
cent, only, and sometimes not at all ; uranic oxide, after gentle ignition
in the air, was reduced in weight by only 0*09 per cent, when strongly
heated in a wind-furnace. fProbably the carbonic oxide disengaged in
the furnace exerts a slight deoxidizing action.]
Caleulation, according to Peligot. Or :
4U 240 8571 2UO 136 4857
60 40 14-29 UH)» 144 51-43
U<0» 280 ~, 100-00 2U0,U«0» 280 ~, 10000
D. GbEBN URANOSO-VRAinO OxiDB. UH)^
Formerly regarded as the Protoxide. — ^Occurs in an impure state, as
PitMlende.^Fortnation.^^1. By burning the metal (p. 158). — 2. By
VOL. IT. M
16i UBAKIUlf.
bmniBf ^e pfolozide.-»Tli« protoxide prepaiod by the m^o m i m^Aod
(p. 159) takes five in tbe air at ordinary tenperatnrei^ and ie oenTeHed,
with eontinuoBS bat feeble glow^ into tbe blaek oxide; and tki«, wbea
beated for a loDj;er time, tame green. (Peligot.) Tbia pyropborie
property of nranie oxalate after being beated in a cnrrent of bydre-
gen gaa, appears to be dne to eondensed bydrogen ; for, on burning tbe
protoxide tbus obtained in a enrrent of oxygen, a small quantity of
water is invariably prodneed. (Rammelsberff.) Tbe protoxide iwepcured
by tbe second metbod, wben keot for a long time at a tenperatore
between l$(f and 200^, tarns bbick (without emission of li^bt or beat)^
and tben, after complete saturation with oxygen, assumes, in tbe course
of i2 or 15 bours^ a green colour. (Ebelmen.) Tbe more ooberent
variety of uranous oxide obtained by tbe first, tbird, or fifth meihed
(p. 159), does not take fire till it is beated to incipient redness: it then
bums with intumescence like a coal, and is converted into uranoso-uranic
oxide. (Quobolz, Arfvedson, Peligot) Under these cireumstances, 100
parts of uranous oxide absorb from 3*695 to 378 parts of oxygen, accord-
ing to Arfvedson ; 3*9 parts, according to EbeUn^; and 40 pirts^ accord-
ing to Peligot
3U0 + » UH>; 204 : 8 «« 100 I S*92.
In tbe flame of the oxy-hydrogen blowpipe, uranous oxide hums with
scintillation. (Clarke.)— 3. By gentle ignition of the sesquioxide. — Tbe
green oxide is almost inyariably formed, wben any other oxide, or the
metal itself, is exposed to the air for some time in a state of gentle igni-
tion ; at a higher temperature, on the contrary, the black oxide is pro-
duced. (Peligot.) — 4. Uranous oxide, heated to redness in an atmosphere
of aqueous vapour, decomposes it slowly, with formation of uraaoeo-uranic
oxide. (Regnault, Ann. Ckm, FhyM. 62, 358.)
Ptvpara^ion.— From Pitchblende, which, besides 40.... 95 per cent,
of uranosO'Uranic oxide, may also contain sulphur, selenium, phos-
pboric acid, lime, magnesia, aJumina, silica, vanadium, manganese,
arsenic, bismuth, antimony, zinc, tin, lead, iron, cobalt, nickel, copper,
and silver. — 1. Powdered pitchblende is dissolved in warm nitro-hyaro-
chloric acid, and after all action has ceased, tbe excess of acid is expelled
by evaporation; the residue treated with a small quantity of hydrocniorio
acid; water added; and the solution filtered from sulphur and silica (and
also from chloride of lead and silver: WiUsCein). The arsenic, lead, and
copper (with bismuth and tin : WitUtein), are then precipitated from the
filtrate oy sulphuretted hydrogen, and the solution agam filtered and
boiled, nitric acid beinfi; added to convert the protoxide of iron into
sesquioxide. Tbe liquid is then supersaturated with a large quantity of
carbonate of ammonia, which throws down the oxide of iron, together
with any lime that may be present, and the greater part of the cobalt
and zinc oxides, retaining in solution the uranic oxide, together with
portions of the cobalt and zinc oxides. [The filtrate often deposits
carbonate of lime in crystals.] The filtrate is boiled as long as carbonate
of ammonia continues to be evolved, by which means tbe three metallic
oxides are precipitated, with the exception of a small quantity of cobalt
oxide, which colours the liquid red; the precipitate is collected on a
filter, and afterwards washed, dried, and ignited, till its yellow colour
changes to blackish green. The resulting mixture of uranoso-uranic
oxide, uranate of zinc, and uranate of cobalt, is lastly digeeted for several
hours with cold dilute hydrochloric acid, which diemyes tbe twe eom«
URANOSO-URANICO X IDE. 163
pomidfl of uraDie ozide» and leares pure nranoso-uranic oxide uDdiraolved.
(Arfredson.) Wittetein (Repert 63, 231), after boiling the solution
with nitric acid, precipitates with caustic ammonia, iostead of carbonate
of ammonia (thereby retaining the lime, maffneeia, and zinc in eolation);
waehes the precipitate by decantation, out of eontact of air; beats it in a
eloee yeeeei with water and a quantity of carbonate of ammonia equal
in weight to half the pitchblende used; filters hot; treats the residue once
more with carbonate of ammonia; OTaporates the filtrate to dryness;
eompletee the operation by beating the residue, and thue obtains uranio
oxide, eontaminated however with oxide of iron. Persos (Ann, Chim.
Fhys. 58, 202) treats the solution with nitric acid, and then boils it with
oxide of copper or of lead, which precipitates the uranic and ferric oxides ;
dissolyes ^e washed precipitate in nitric acid; boils the solution with
mtreuric oxide, which throws down nothing bat ferric oxide; dilutes the
filtrate with water; and removes the mercury and copper by a curtent of
sulphuretted hydrogen. The eolation after this treatment retains nothing
but uranium «
2. The finely divided pitchblende is freed by elntriati<Hi from die
lighter earthy impurities; roasted for a short time to save nitric acid;
then dissolved in that add, and the solution evaporated to dryness. The
residue is exhausted with water; the solution filtered from the brick-
red mixture of ferric oxide, arseniate of ferric oxide, and sulphate of
lead; the greenish-yellow filtrate slightly evaporated, and allowed to
oool, whereupon it deposits crystals; and the resulting radiated mass of
crystallized nitrate of uranic oxide, drained on a glass funnel, and then
washed with a small quantity of cold water. As the water dissolves a
portion of the uranium salt, it is used in a subsequent operation to redis-
solve the dry residue obtained by evaporating the solution of pitchblende
in nitric acid. The uranic nitrate after being dried in the air, is then
hitrodnced into a wide-mouthed bottle containing ether, in which it
immediately dissolves; the yellow solution is left to evaporate sponta^
necmsly in the air, and the crystals obtained are purified by solution in
hot water and recrystallization. They are converted into uranoso-uranic
oxide by ignition. From the mixed mother-liquids diluted with water,
arseuic, I^mI, and copper are precipitated by sulphuretted hydrogen,
and ferric oxide removed from the filtrate by evaporating to dryness,
and redissolving in water. The solution thne obtained yields a fresh crop
of crystals of uranic nitrate. (Peligot.)
3. Ebelmen frees the pitchblende, by digestion in dilute hydrochloric
acid, from the adhering carbonates of lime, magnesia, protoxide of man-
ganese, and oxide of copper; then washes it with boiling water; mixes
it with charcoal; ignites strongly, whereby a portion of the sulphur
and arsenic ie expelled ; treats the cooled mass with strong hydrochloric
acid, which dissolves lead, iron, and a small quantity of copper (without
any uranium); washes the residue with a large qnantity of water; and
roasts it to expel the remaining sulphur and a portion of the arsenic.
After this, he treats the mass with nitric acid, which leaves quartZHsaud
and ferric oxide undissolved; evaporates the solution containing alumina,
inanium, arsenic, lead, iron, copper, and even antimony, nearly to dry-
ness; rediesolvea the residue in boiling water, which leaves the mater
part of the iron and arsenic in the form of insoluble arseniate of ferric
oxide; boils the filtrate with sulphurous acid; precipitates the rest of the
arsenic, together with the copper and lead [and antimony], by a current
of hydrosuTphuric acid; evaporates the filtrate, which now contains nothing
m2
164 URANIUM.
bat nranio oxide with a small quantity of ferric oxide and alamina^
to dryness; dissolves in water, which leaves the ferric oxide; and
purines the uranic nitrate by repeated crystallization. From the
mother-liquids obtained in this process^ the ferric oxide and alumina are
precipitated by careful addition of a small quantity of ammonia; and
the filtrate mixed with excess of ammonia to precipitate the nranic
oxide, which — ^after being ignited and freed from any adhering lime,
ma^esia, and protoxide of manganese, by cold, moderately strong,
hydrochloric acid — is washed, dissolved in nitric acid, and obtained in the
crystallized state as nitrate of uranic oxide. If the ciystallized uranic
nitrate is required absolutely pure, it must be dissolved in a small
quantity of water; a hot concentrated solution of oxalic acid added to the
liquid ; and the precipitated uranic oxalate washed with boiling water,
and converted into uranous oxide by ignition in a covered platinum
crucible. The uranous oxide is then to be digested for some time in c(hi-
ceutrated hydrochloric acid ; washed with water ; dissolved in nitric acid ;
crystals of uranic nitrate obtained from the solution; the crystals redis-
solved in water, and a^n precipitated as above by oxalic acid; the
precipitate again washed with hot water, and lastly ignited in the air.
(Ebelmen.)— Pitchblende (Fechuran) is dissolved in warm dilute nitric
acid; the filtrate freed by hydrosulphuric acid from arsenic, lead, and
copper, and then evaporated to dryness; the residue digested in water,
which leaves the oxides of manganese, iron, and cobalt, undissolved; and
the uranic nitrate contained in the solution, purified by repeated crystal-
lization. (Wertheim, J, pr. Chem. 29, 210.)
4. An intimate mixture of pitchblende with half its weight of nitre*
is kept at a red heat in a crucible for 20 minutes, and frequently stirred;
the fused mass exhausted by repeated decantation with water, which
dissolves the silicate of potash ; and the insoluble portion treated with
excess of pure concentrated nitric acid, which leaves the greater part of
the ferric oxide undissolved. The clear liquid is poured off and eva-
porated nearly to dryness; the greenish residue mixed with water,
which separates ferric oxide (from which the still adhering uranic oxide
is separated as fickr as possible by solution in nitric acid) ; the solution
filtered; again evaporated to dryness to decompose the remaining ferric
nitrate; and redissolved in water, to which, if the uranic oxide does
not entirely dissolve, a portion of nitric acid is added. Lastly the filtrate
containing oxide of lead, uranic oxide, and lime is mixed with excess
of carbonate of ammonia till the precipitate, which is yellow at first,
becomes white ; the solution is then filtered from carbonate of lime and
oxide of lead, and lastly, boiled and evaporated to dryness, to separate
the whole of the uranic oxide, which is then calcined. (Lecanu & Serbat.)
It is better to evaporate to drjmess, and treat the residue with water
only. By this means the nitrate of ammonia is dissolved free from uranic
oxide, while carbonate of uranic oxide remains undissolved. (Laugier.)
Carbonate of ammonia is preferable to carbonate of potash or soda>
because it does not dissolve the oxide of lead. (Lecanu & Serbat.)
Quesneville (/. Pharm. 15, 494), who in other respects follows Arfved-
son's method, uses sal-ammoniac mixed with carbonate of potash or soda^
instead of the carbonate of ammonia, on account of the costliness of the
latter; but the saving is probably but trifiing.
* Laugier states that ttom 1 to 1^ pt. nitre to 1 pt. pitchblende is required for the
oomplete oxidation of the nranian.
URANOSd-URANIC OXIDE.
165
5. To 8 parts of yeiy finely powdered pitchblende contained in a
capaciouB vessel, 9 or 10 parts of oil of vitriol are gradually added, the
mixture being well stirred with an iron rod; whereapon the mass increases
greatly in biuk, and becomes hard and lumpy. It is then kept in a warm
place for several days and stirred frequently, during which time it absorbs
water and becomes thinner and greyish white. It is then evaporated to
dryness in an iron vessel ; the mass broken up and again heated more
strongly, with constant stirring, as long as the sulphuric acid in excess
continues to evaporate, and till the residue assumes a dull reddish-yellow
colour. When cold, it is repeatedly boiled with fresh quantities of
water; and the greenish-yellow filtrate saturated with hydrosulphurio
acid, of which a small Quantity only is required, as the greater part of
the metals precipitable oy it are left behind in the insoluble residue.
The solution is then filtered from the sulphides; the hydrosulphurio acid
expelled by boiling; the liquid again filtered from any precipitate that
may have formed; the filtrate boiled for some time with nitric acid, to
convert the uranous oxide into uranic oxide; supersaturated after cooling
with a dilute solution of carbonate of ammonia; set aside for some time,
and frequently stirred; and lastly, filtered and boiled, till carbonate of
nranic oxide separates from the liquid; the precipitate thus obtained is
well washed with water. The filtrate yields sulphate of ammonia by
evaporation. One part of powdered pitchblende may also be heated with
5 parts of bisulphate of soda (as obtained in the preparation of nitric
acid from Chili-saltpetre), till the mixture fuses tranquilly; the greenish-
yellow mass reduced to powder, and exhausted with boiling water ; and
the filtrate treated as above with hydrosulphurio acid, nitric acid, and
carbonate of ammonia. (Werner, J, pr. Chem, 12, 381.) The metho<ls of
Richter and Bucholz are less satisfactory, that of Brando least of all.
Properties, — As obtained by bummg the metal or by igniting the
carbonate of uranic oxide, it forms a dull ffreen powder. (Arfvedson.)
Dark olive green, velvet-like powder. (Peligot.) That obtained by
Igniting uranate of ammonia forms black, very dense, hard fragments,
which likewise yield a dingy green powder. (Arfvedson.) Sp. gr. =
7-1932 (Karsten.) = 7-31 (Ebelmen.)
Calctilaiion, according to Peligot.
Or:
3U
40
180
32
.... 84-91
.... 1509
V^O^
68 .... 32*08
144 .... 67-92
Or:
3UO
O
204
8
212
■ •••
«■■•
.... 10000
96-23
3*77
uo.u*o»
Peligot.
96-2
«)*o ....
212 .... 10000
Marcband. Arfredaon.
96-4 .... 96*465
3*6 .... 3*535
U»0^
212
100-00
100-0
100*0
100-000
Beneliiu.
3UO 96*44
O 3-56
Badiolz.
95-1
4-9
Schonberg.
94
6
VH}* 100-00 .... 100-0 .... 100
tJ«0^ BsS . 802-49 + 4 . 100 = 2807*47. (Beneliiu.)
Berzelius, Arfvedson, Peligot, Marcband (J. pr. Chem. 23, 498), and
Rammelsberg, estimate the amount of oxygen by the lossof weight which
the uranoso-nranic oxide sustains when converted into nranons oxide by
ignition in hydrogen gas.
166 URANIUM.
Peligot ftttribatM the noftller lo«0 of weight obtained bj Arfyedflon to
the f»ct of hi« green oxide being mixed with a portion of black oxides
According to Rammebberff, howeyer, the Iom varies between 3*83 and
4*67 per cent., and, aocordinglj, cannot ficrre for the exact determina-
tion of the atomic weight of uraniunt
Deeampontions. — 1. Bj strong ignition, with loss of from 0*7 to 1 per
cent, of oxygen, learing black oxide. (Peligot.) — 2. By potassiam,
sodium, charcoal, hydrogen, or sulphur at a red heat, it is converted into
uranous oxide. The action of potassium on soda is attended with slight
incandescence. (Gray-Lussac & Th^nard.) Hydrogen gas acts rapicUy^
the oxide becoming red-hot (Arfvedson.) By ignition with sulphur,
uranoso-uranic oxide is converted into black uranous oxide entirely free
from sulphur. (Ebelmen.)
Combinatiant. — a. With water. — Hydrated Ubanoso-urakio Oxidb.
-*-l. Formed when a solution of uranoso-uranic oxide in an acid is precipi-
tated by ammonia. — 2. When protochloride of uranium is precipitated
by ammonia, the hydrated protoxide which separates, absorbs oxysen
during the washing and is converted into hydrated uranoso-uranic oxide.
(Rammelsberg.) — ^3. A solution of uranic oxalate, exposed to the direct
rays of the sun, deposits a violet-brown flocculent precipitate of hydrated
uranoso-uranic oxide, which must be collected before the whole of the
salt is decomposed, so that it may not become contaminated with hydrated
uranic oxide. It is washed with boiling water, and dried in vacuo on
a heated support. (Ebelmen.)
The hydrate obtained by the first method is dark greyish green
iBerzelius), or sometimes purple-brown. (Arfvedson.)— -When heated
or several hours in the solution, it condenses to a heavy powder. (Arf-
vedson. )~- When prepared by the second method, it is greenish black.
(Rammelsberff.) — The third method yields it in a solid black mass, with
brilliant conchoidal fracture ; when ignited in a current of nitroeen fras,
it gives off its water without any change of appearance, and stiu yields
a green powder. (Ebelmen.)
Dried in vacuo otter oU qftfitrioL Rammelsberg (2).
U»0* 212 88 70 8906
3HO 27 11*30 10-94
U»0*,3H0 239 ZZ 10000 ZZ 10000
The hydrate loses its water when heated, and leaves green uranoso-
uranic oxide. (Arfvedson.) An aqueous solution of carbonate of ammonia
resolves it into uranic oxide, which dissolves an insoluble brown hydrate
of uranous oxide. (Berzelius.) When the hydrate precipitated by the
first or second method is exposed to the air in a moist state, it is converted
— if any alkali still adheres to it — into a yellow uranate of the alkaline
base. (Arfvedson.)
b. With Acids, forming the Salts of Uranoso-uranic Oxide, or
Uranoso-uranic Salts. — Uranoso-uranic oxide, after ignition, dis-
solves very slowly and sparingly in dilute hydrochloric and sulphuric
acids ; more readily, however, in the concentrated acids, and completely
in boiling oil of vitriol. (Arfvedson.) The uranoso-uranic oxide obtainea
by burning the metal dissolves readily in acids. (Lecanu.) The hydrate
dissolves very easily, excepting when its density has been increased by
heating it for several hours in the liquid from which it was precipitated.
(Arfvedson.) The yellowish green solution thus obtained may be supposed
URANIG OXIDE. 16T
to conaisk of a sdxttite of manoiis and araaio nlia ; henoo, from a solation
of tbe greoD oxide in sulphurio acid, alcohol precipitates sulphate of
uranous oxide, whilst sulphate of urauic oxide remains dissolved, and
imparts a pure yellow colour to the liquid. A concentrated solution of
the green oxide in hydrochloric acid behaves in the same manner, on the
addition of sulphuric acid and alcohol. (Berzelius.) The uranoso-uranic
salts have a green colour and rough taste. By exposure to the air, and
by the action of nitric acid, even in the cold, they are converted into
nranic salts. They are precipitated gre3riBh green, or brown, by putB
alkalis. With alkaline carbonates they yield dingy, light green precipi-
tates, soluble in excess of the precipitant and forming a greenish solu*-
tion. With phosphate of soda they yield dull greenish white precipitates;
black with alkaline hydrosnlphates ; pale y^lowish green, with oxalic
acid, eren when that acid is in large excess; brownish red, with ferro-
o^nide of potasBinm; and, according to Berselios, reddish brown wiU&
tmotitre of galk. Hydrosalphiiric acid has no action on these salts.
E. Ubanic Oxide. U*0».
Sei^ioande of Uranium, Utanoxyd.
Uranium and its lower oxides dissolve readily in nitric acid, with
erolution of nitric oxide and formation of nranic nitrate. Uranous oxide
decomposes nitrate of silver in solution, without erolution of gas, metallic
silrer being precipitated and uranio nitrate formed. (Ebeunen.) The
hydrate of nranons or nmnoso-nranio oxide is not converted into nranic
oxide by exposure to air in a moist state, unless an alkali is pres^it,
with which the ttianio oxide can combine. (Peligot.)
Preparation, 1. By heating the hydrate of umnic oxide to a tempera-
ture not exceeding 300^ (Ebelmen.) According to Malaguti, the residue
still contains water FVid. HydraU qf Vranie O^e], — >2. By keeping the
double carbonate of uranous oxide and ammonia at a temperature of
about 300^ for a considemble timoi till the whole of the ammonia and
carbonic acid are expelled. (Ebelmen.)
2U...
30...
»••#•• t*..t
Ci]
colstion,
120
24
sceordiiig to Pdlfgoi
83-33
16-67
Or;
«t)0
u«os
1
ISO
8
94-44
5*60
144
10000
ArfVedson.
04-73
6-27
Schoaberf.
91-3
8-7
144
•■••
lOO'OO
10000
1000
(U^Oa s 2 . 802*49 + 3 . 100 = 1904*98. BerzeUas.)
Formerly, UO, or rather dUO, was regarded as metallic uranium,
IPO^ as the protoxide, or as containing one atom of oxygen, and U*0' (as at
present) as a combination of 2 atoms of uranium with 3 atoms of oxygen.
These oxygen compounds are now expressed by the following formulae:
The former metal, now the protoxide s UO ; the former protoxide, now
oranoso-uranio oxide = U'O*) the ses^uioxldo ^ JJHJ^. If in each of
168 URANIUM.
these formnlfld we snppoae 8U to be present^ and deduct UH)*| wbich
reptesents the former metal, we obtain the following proportions of oxygen
between the former protoxide and the sesquioxide.
The former metal. The former protoxide. Sescfuoxide.
U»0» \PO* vou
-U«0«= • O 0»4
Hence it is apparent : first, why both in the former and in ike present
protoxide the proportion of oxygen to the former or present sesquioxide
IS = 2 : 3; and secondly, why the present atomic weight of the protoxide
and sesquioxide of uranium should be a third of its former amount.
According to Arfredson and Berzelius, the atomic weight of uranium,
formerly so called, was 217; this is now regarded as UH)*; and if from
this we deduct the atomic weight of 3 atoms of O, the atomic weight of 3
atoms of U will be = 1 93 ; consequonlty that of one atom of U = 64*3 ;
but according to the researches of Peligot, Kammelsberg, Ebelmen, and
Wertheim, the actual atomic weight is 60.
DecomposUiatu, By simple ignition, into oxygen gas and green ura-
noso-uranic oxide. (Ebelmen.)
Camhinatums, a. With water.— -Htdrated Uranic Oxide. — Occurs
native in the form of UraniuiiP'Ochref a lemon-yellow, friable substance,
which, when ignited, gives off water and oxygen gas, and is converted «
into the green oxide. (Berzelius, Fogg, 1, 374.)— 1. An aqueous solution
of uranic oxalate is exposed to the direct rajrs of the sun, till the brown
precipitate of hydrated uranoso-uranic oxide, which first appears, turns
yellow, and all the oxalic acid is resolved into carbonic acid and carbonic
oxide ,* the precipitate is then purified with water, and dried in the air.
(Ebelmen.)— 2. A solution of uranic nitrate in absolute alcohol is eva-
porated at a moderate heat, not reaching to the boiling point, till, at
a certain degree of concentration, nitric ether is disengaged; from the
residual orange-yellow spongy mass, the undecomposed uranic nitrate is
dissolved by water, and the remaining hvdrated oxide is then washed con*
tinuously with boiling water. (Malaffuti, Compt rend, 16, 851.)
Hydrated uranic oxide, when curied in the air, has a lemon-yellow
colour; when dried in vacuo, it acquires a shade of orange-yellow. It is
permanent in the air; does not absorb carbonic acid; exposed to a tem-
perature of 300*^, it yields anhydrous uranic oxide ; at a red heat it is
converted into green uranoso-uranic oxide. (Ebelmen.) — ^At 15° it exhibits
a lemon-yellow colour, and has a specific gravity of 5*926. At 400^ it
loses only a third of its water ; at a higher temperature, the whole is given
off (if it be perfectly free from acid) ; a portion of oxyeen gas, however,
always escapes with the last traces of water, leaving a brown mixture of
the olive green and black oxides of uranium. (Malaguti.)
Calculation,
a, Ebelmen. Malagati.
U«0» 144 .... 9412 .... 93-75 .... 9389
HO 9 .... 5 88 .... 6-25 .... 611
U«0»,HO .... 153 .... 10000 Z, 10000 Z. 10000
b, Ebelmen.
UW 144 .... 88-89 .... 88-35
2HO 18 .... 11-11 .... 11-65
UK>»,2H0 162 .... 100*00 Z 100*00
UHANIC OXIDE. 169
a 18 the hydrate dried at ordinary temperatures in vacnoi or at 100^
in the open air. — h ia the hydrate dried in the air at ordinary tens*
peratures.
(. With Acids, forming the Salts of Uramio Oxide, or Uranic
Salts. These salts are obtained by oxidizing the uranous or nranoso-
nranic salts by nitric acid or by exposure to the air, and in an impure
state by dissolving the alkaline uranates in acids. Most of them contain
one atom of IPO' combined with one atom of acid. This fact, according
to Peligot, tends to establish the assumption that 2U0 or U^O' is a com-
pound metal {UranyJ), and that uranic oxide, U'O^ should rather be
considered as the oxide of uranyl (U'O^) + ; for, other bases containing
3 atoms of oxygen, e. g. APO*, Ci*0', Fe'O', require, 3 atoms of acid to
produce a normal salt. According to Berzelius, however, this oxide
forms sulphates composed of IP0»,2S0* and U*0',3S0', as well as U*0',
SO^ — and a nitrate containing IP0',3N0', as well as that which is com-
nosed of U'0',N0^ : now, since nitric acid does not form acid salts, the
latter must be regarded as the normal; and the former, as well as the
other salts, which to one atom of base contain only one atom of acid, must
be considered as basic salts, notwithstanding their solubility and acid
reaction. {Vid, pp. 178 woA 177.^
The uranic salts have a yellow colour; they are mostly soluble in
water, and when dissolved, have a very rough taste, without any subse-
quent metallic flavour. Most of them redden litmus. The sulphate and
nitrate of uranic oxide turn turmeric brown even when they contain excess
of acid. (Bucholz.) Those which contain a volatile acid part with it at
a red heat. They are reduced to uranous salts by hydrosulphuric acid
(Berzelius); also by trithonic acid (Persoz); and oy alcohol or ether in
direct sunshine. (Bucholz.) — Hydrochlorate of uranic oxide, supersatu-
rated with hydrochloric acid, is converted by metallic zinc, cadmium, tin,
lead, iron, cobalt or copper ^with formation of dichloride of copper), into
hydrochlorate of uranous oxiae ; by the prolonged action of zinc, a green
or brown viscid mass is produced, which appears to be a compound of
oxide of zinc with protoxide of uranium ; from a solution of monohydro-
chlorate or nitrate of uranic oxide, zinc separates only a small quantity
of uranic oxide, which, by enveloping the zinc^ prevents any further
action. (Fischer, Fogg, 9, 265; 16, 126.) With pure ammonia, potash,
or soda, these salts give an orange-yellow precipitate (alkaline uranate)
insoluble in excess of the reagent; — ^with carbonate of ammonia, potash,
or soda — ^pale yellow, soluble in an excess of the alkaline carbonate (less
readily in monocarbonate than in bicarbonate of potash and sesquicarbo-
nate of ammonia, which latter solution again yields a precipitate on
boiling*); also with carbonate of lime (Fuchs); — ^with phosphate of soda
•^unless the acid in the uranium solution is in too lar^e excess — yellowish
white (phosphate of uranic oxide); — with alkaline hydrosulphates,
brownish black (sulphide of uranium, which takes a long time to settle
completely down to the bottom of the vessel, so that the liquid remains
black for a considerable time) ; — with sulphite of ammonia on boiling,
yellow granular sulphite of uranic oxide; — with oxalic acid and alkaline
* \ Ebelmen states that 1 part of the salt diasolyed in 333 parts of water gives a bright
yellow ooloar with carbonate of potash, 1 part in 666 pts.^ a distinct yeUow; 1 part in
2664 pts., a jellow colour, perceptible after some minutes, with pore potash; 1 part in
5328 pts., a faint yellow tinge; 1 part in 10,656 ^.^ a distinct optlescenoe^ after half
an hoar. (M Asm. Ckim. Ph^,^ 5, 189.) f
170 UBANIUM.
(oaitAm, yellow (oxalato of oianic oxideV— with alkaline aacciiiatesi
yellow, from a solution containing not less tban one part in 1 000 ; — ^wiUa
tincture of galls, chocolate-brown; — with ferrocyanide of potassium,
bright brownish red. (Klaproth, Berzelius.) — Before the blowpipe with
flaxes, the salts ffive the same characters as nranic oxide itseli. — The
salts of uranic oxide form with salts of the alkalis, a great namfoer of
yellow doable salts, in which the former lose their acid on exposure to
heat, but with less facility tban when nncombined.
c. With electro-positive salifiable bases, producing compounds which
may be called Uranates. The compounds of uranic oxide with all the
alkalis are formed by precipitating a uranic salt with an alkali ; the xasr
nates of baryta, lime, magnesia, and rarious heary metallic oxides, are
formed by adding ammonia to a mixture of a uranic salt with one of these
bases; in this case, howerer, the precipitate contains more or less ura-
nate of ammonia. The uranates are for the most part yellow, and, after
ignition, orange-yellow. The uranic oxide contained in them remains unde-
composed at a red heat, prorided the base is permanent in the fire ; at a
white heat, however, it is generally reducea to uranoso-uranic oxide.
Hydrogen gas, at a red heat, reduces the uranic oxide to metal [protox*
ide], and generally also the other metallic oxide (the alkalis excepted) ;
the residual mass, after ignition with hydrogen, is in all cases inflam-
mable in the air at ordinary temperatures. (Arfredson.)
UltANIITM AND GaRBOK.
A. Carbonate ov URANOflO-uRANic Oxibb. — Sulphate of uranoso*
nranic oxide gires with carbonate of ammoniai not in excess, a pale green
precipitate. (Arfvedson.)
B. Carbonatb ov Uranic OxiDB.*-Remains in the form of a bright
orange-yellow powder on gently heating the double carbonate of uranic
oxide and ammonia. (Lecanu, Peligot.) [See also Ebelmen, p. 182.]— The
lemon-yellow precipitate obtained on treating nitrate of uranic oxide with
carbonate of potash, after being washed with cold water and dried in the
air, contains 3*66 per cent, of potash, 8*87 of carbonic acid, 81 *98 of nranic
oxide, and 10*49 of water, and is probably only a loosely combined mix*
ture of uranic oxide and monocarbonate of potash. (Ebelmen.) [Com-
pare further Berzelius, p. 182.] — According to Brande, hmpure] hyarated
uranic oxide dissolres in aqaeous carbonic acid, and on neating the liquid,
is again precipitated almost entirely free from carbonic acid*
TJAANitrx AND Boron.
The greyish green precipitate which borax gives with protochloride of
uraniam, consists almost wholly of hydrated protoxide; it blackens
quickly, and turns yellow after long exposure to the air. (Bammelsberg.)
Borate of Uranic Oxide, or Uranic Borate. — Prepared by pre-
cipitating a uranic salt with borax; it is of a light yellow colour, and
very sparingly soluble in water. (Richter.)
URANIC PHOSPHATE. ITI
UsAKiuK Ain> PnoaraoBus.
A. Phosphate of Uranous Oxide, or Ubanovs Phosphate. — Di-
phosphcUe, — An excess of diphosphate of soda completely precipitates
protochloride of araniam. The green gelatinous precipitate gives up the
whole, or nearly the whole of its phosphoric acid to potash, but none to
ammonia. Even when recently precipitated, it dissolves only in concen-
trated hydrochloric acid, and is again thrown down on the addition of
water. — Pyrophosphate of soda gives the same precipitate, which, on
ignition, loses 1266 per cent, of water. (RammelsDerg.)
Dried over oil qf vitriol, Rammelsberg.
2UO 1360 68-02 59-62
cPO* 71-4 30-47
3HO 27-0 11-51 11-43
2UO,HO,ePO< + 2Aq. 234-4 100*00
B. Phosphate of Ubanio Oxide, or Ubanic Phosphate. Ya.
Triphosphate. dlPO^ P0^ This compound appears to exist in certain
double salts. Thus, whe n tribasic phosphate of soda, dNaO, PO^, and
nitxate of uranic oiide are mixed in equal numbers of atoms, a light
yellow powder is precipitated, which acquires a slight greenbh tint when
Ignited, and retains this colour on cooling. It appears to be composed of
(UW, 2H0) P0*+3IP0», PO»+xAq.— When nitrate of uranic oxide is
mixed with a moderate excess of triphosphate of soda (a very large
excess would redissolve nearly the whole of the precipitate), a dark yel-
low precipitate is obtained, which is insoluble in water, and appears to
consist of (NaO, 2UK)») PO«-f 3U*0', P0». The same salt is obtained
when triphosphate of soda is mixed with a quantity of uranic nitrate not
sufficient to decompose the whole of it. When the triphosphate of soda is
added in sufficient ezcesn to redissolve part of the precipitate, the inso-
luble residue is a mixture of different salts.
b. Diphoiphate.—(2Vy\ HO) PO«+xAq.— 1. When uranic oxide is
digested in a small quantity of aqueous phosphoric add, a yellow saline
mass is produced, part of which (c) dissolves in boiliug water, while the
rest remains undissolved. The insoluble portion is an amorphous, light
yellow powder, which becomes darker when ignited, but resumes its ori-
ginal colour on cooling. It contains 4 atoms of water, three of which
are ffiven off between 120'^ and 170^, and the fourth, the basic atom, at
a red heat.
Calcnlatioiu Werther.
2U«0» 2880 .... 72-85 7216
P0» 71-4 .... 1805 ^ 17-96
4HO 36-0 .... 9-10 9-66
(2UH)»,HO)PO« + 3Aq. 395*4 .... 100-00 90-78
2. Phosphoric acid, added to a solution of uranic acetate, throws down
a precipitate, having a distinctly crystalline character, of somewhat
darker colour than the preceding, but exhibiting similar phenomena when
ignited. After drying in the air at ordinary temperatures, it contains
9 atoms of water, and is composed of (2U'0^ HO) POH 8Aq. Of these
172 URANIUM.
9 atoma, two are driven off at 60'', leaving a salt composed of (2UH)*^
H0)P0^+6Aq. Of the 7 atoniB of water contained in this last-men-
tioned compound, six are driven off at 120®, and the seventh at a red
heat. The same salt with 7 atoms of water is obtained when nitrate of
nranic oxide is added to a solution of ordinary diphosphate of soda
(2NaO, HO, PO*^ or to the mother-liquid obtained when triphosphate of
1, PO*) is imperfectly decomposed by nitrate of nranic oxide.
soda (dNaO,
Calculation. Weither.
2U«0» 288-0 .... 68*19 .... 68-10
PO» 71-4 .... 16-89 .... 16-94
7H0 63-0 .... 14-92 .... 1496
(2U50»,HO)PO» + 6Aq 422-4 .... 100-00 .... 10000
Calculation. Werther.
2U20» 2880 .... 65-39 .... 65-30
P0» 71-4 .... 16-21 .... 16-26
3H0 81-0 .... 18-40 .... 18-44
(2U«O»,H0)P0» + 8Aq 440-4 .... 10000 .... 10000
(Werther, /. pr. Ghent. 43, 321.) T
When phosphoric acid is added to a solution of uranic acetate, or
ammonia to a solution of acid nranic phosphate, yellowish white flakes
are obtained, scarcely, if at all, soluble in water, but easily soluble in
carbonate of ammonia. From the latter solution they are again sepa-
rated on evaporating the liquid. (Laugier, Ann, Chim, Phys, 24, 23.)
Calculation. Laugier.
2U20» 2880 .... 64-09 .... 610
P0» 71-4 .... 15-89 .... 16-6
lOHO 90-0 .... 20-02 .... 220
2U2O>,PO*+10Aq 449-4 .... lOO'OO .... 99-6
[This result, which is not in accordance with Werthcr's, can scarcely be depended
upon, inasmuch as the analysis differs widely from the calculation. (W.)]
c. Acid Fkoaphate. 1. Prepared by dissolving the diphosphate or
the carbonate of uranic oxide m excess of phosphoric acid. Not crys-
tallizable, but forms a pasty mass, which becomes moist when [exposed
to the air. (Richter.)
IT 2. The solution obtained by digesting uranic oxide in a small
quantity of aqueous phosphoric acid, boiling the resulting yellow saline
mass in water, and decanting from the insoluble diphosphate (b, 1),
deposits, when sufficiently concentrated, and then left to evaporate in
vacuo over oil of vitriol— a lemon-yellow salt in distinct but closely-
grouped crystals, too small to be measured. These crystals, when gently
heated, give off part of their water and become pale yellow. A red heat
is required to expel the remainder of the water completely ; but the
greater part of it may be driven off by continued exposure to a temperar
ture of 170°— 200°: under these circumstances the salt swells up. It
does not fuse or part with any portion of its acid even at the highest
temperatures. When digested in water, it is decomposed, phosphoric
acid and uranic oxide being dissolved, and a basic salt remaining behind.
On dissolving it in phosphoric acid, and adding ammonia to the solution,
a yellow salt containing ammonia is precipitated.
i
SULPHIDE OP URANIUM. 173
Calcvlation. Weiiher.
(1) (2)
tJ»0» 144-0 ..M 55-20 .... 55-9 .... 5460
PO» 71-4 .... 27-47 .... 26-7 .... 27-49
5HO 45-0 .... 17-33 .... 16-8 .... 17-20
(U'0»,2H0) PO» + 3Aq. 2604 .... 10000 Z. 99-4 .... 9929
On comparing the several nranio phospliates examined by Werther,
it will be seen that uranic oxide, in its relations with phosphoric acid,
behaves like an oxide containing only one atom of oxygen (NaO, for
example) — ^inasmuch as all these compounds are tribasic, the three atoms
of base being made up either of 3IP0', or of 2U*0' and IHO, or of
IIPO^ and 2H0. So far, the composition of these salts tends to corrobo-
rate Peligot's view (p. 169) of the nature of uranic oxide. It will here-
after be seen {chap, 24) that the arseniates of uranic oxide exhibit the
same analogy. T
URANiirH AND Sulphur.
A, Protosulphide of Uranium.— -Metallio uranium combines with
sulphur at the boiling-point of the latter, with evolution of light and
heat. (Peligot.)— -The protosulphide is prepared by passing the vapour of
bisulpnide of carbon over nranoso-urauic oxide heated to redness in a
porcelain tube. (H. Rose, OUb, 73, 189.) Hydrosnlphuric acid gas,
passed over ignited nranoso-uranic oxide forms nothing but uranous oxide
mixed with a very small quantity of sulphide of uranium. (Arfvedson.)
When uranous or uranoso-uranic oxide is heated to redness with sulphur,
nearly all the sulphur escapes, according to Lecauu — and the whole of it,
according to Ebelmen — while black uranoso-uranic oxide remains behind.
Protosulphide of uranium is yellowish black ; when rubbed on a
smooth surface, it leaves a black metallio streak. When heated in the
air, it bums with a sulphurous flame, leaving uranoso-uranic oxide.
(Rose.) It is but slightly acted on by hydrochloric acid ; but nitric acid
dissolves it even at ordinary temperatures, with separation of sulphur.
(Berzelius.)
Protochloride of uranium dropped into an excess of bihydrosulphate
of ammonia, disengages hydrosulphuric acid, and forms a blackish precipi-
tate which, when washed, acquires a superficial grey tint, and behaves
like a mixture of hydrated uranous oxide and sulphur. (Rammelsberg.)
The black precipitate, which alkaline hydrosulphates give with ura-
noso-uranic salts, is either anhydrous or nydrated ^-^lUpkide of Ura-
nium. — The dark-brown jprecipitate produced by alkaline hydrosulphates
in salts of uranic oxide is either annydrous or hydrated SesquisiUphide
of Uranivm, — According to Berzelius, the latter dissolves in an excess of
the alkaline h^drosulphate, yielding a dark brown solution ; it likewise
dissolves sparingly in the water with which it is washed, and forms a
brown solution. If exposed to the air while yet moist, it oxidizes and
is soon converted into a mixture of sulphur and hydrated uranoso-uranio
oxide ; the oxide may be dissolved out by hydrochloric acid. If, however,
during its exposure to the air, a portion of the solution containing the
alkaline hydrosulphate is left in contact with it, an orange-yellow sub-
stance is produced, which Berzelius regards as a compound of sulphide of
uranium and uranic oxide [or an alkaline uranatel]. The same substance
is obtained when hydrosulphuric acid gas is passed through an alkaline
174 VRAKIUM.
uranate diffused in water till it acquires an orange-yellow colour (a very
large excess of hjdroeulphurio acid would give rise to the production of too
large a quantity of brownish black sulphide of uranium). The compound
dissolves in hydrochloric acid, forming a green solution, with eyolution of
hydrosulphuric acid gas and separation of sulphur. (Berzelins.) The
sulphide of uraniuroj precipitated by alkaline hyarosulphates, dissolves in
an aqueous solution of sulphurous acid; the yellow solution deposits the
greater part of the uranium on boiling. (Berthier, Ann, Chim. Fkys. 50,
369.)
Hydrosulphite of soda in ezceiis gives with protochloride of uranium
a greyish green precipitate, consisting of a mixture of sulphur and basic
sulphite of uranous oxide, solphurous acid being set free at the same time.
(Rammelsberg.)
B. Sulphite op Uranous Oxide, or Uranous Sulphite. — Dmd-
pkUe. — Monosulphite of soda gives with protochloride of uranium, a
grejrish green precipitate, the formation of which is attended with disen-
gagement of sulphurous acid. When the sulphite of soda is in excess,
the filtrate still retains a portion of the salt in solution, the liquid having
a green colour; after long standing, however, sulphurous acid is evolved,
ai3 the salt again deposited. When heated, the salt loses water and
sulphurous acid, and leaves uranons oxide, or, if air is present, uranoso-
aranic oxide. It dissolves readily in acids. (Rammelsberg.)
lUO
SO»...
2HO
t »#••• • v*« ••«^
Dried mm M qfvitrM.
Kaoi fnelsbCT^.
136 .... 7312
72-03
32 .... 17'2«
1€'S0
IS ... »'6d
2UO,SO^ + 2Aq 186 .... lOe-Oe
C. SuLFHiTB ov Uranio OxiMB, or Uranic Sulphitk. — U^,SO*
-f dAa.— Precipitated as a ydlow granular powder, on boiling a solotion
44 caroonate of nranie oxide and ammooia in a solution of sulphnrons
acid or a uranic salt with sulphite of anuBooia. (Berthier.) IT Floooulent
precipitate, permanent in the air, but resolved by heat into sulphurous
acid and a brown residue, prebaUy eossisting of a mixture of uranous
and uranic oxides. It may also be piepaied by passiiig a current of sul«
phurous acid through hydnited uranic oxide diffused in water.
3HO.
C«lciilatio».
Mnsprmtt.
144 .... 70-89
71-72
32 .... 16-82
14-70
27 .... 13-28
13-58
U2o',so»+aA<i^ 203 .... loeoe loeoo
(Muspratt, Ann. Fharm, 50, 259,) T
D. Sulphate of Uranous Oxide, or Uranous Sulphate. — a. Di*
sulphate, — 1. Remains as an insoluble residue on treating the uormal salt
with a large quantity of water. (Peligot.) — 2. A solution of monosulphate
of uranic oxide in dilute alcohol, exposed to the sun*s rays, becomes
colourless, and deposits the basic salt, at the same time emitting an odour
of aldehyde. (Ebelmen.) — 3. An aqueous solution of the normal salt is
boiled with green uraaoso-uranic oxide, and the liquid decanted while
k
URANOUS SULPHATE. 175
•till k«l from ilie nH a tberttbr prodneed, beeaaie it rediisolyes on cooling.
(Ebelmen.) — 4. Bj oMefnl addition of ammonift to a solution of tbe nor-
ma] salt, the salt a is precipitated. (Rammelsberg.^ — The salt is eol-
leoted on a filter, waslied with a small quantity of cold water, and dried.
—It forms a H^t green powder, eometkaeB havin|; a silky lustre. (Peli-
got, Ebelmen.) I^rge quantitieB of watw (espeeially if boiling) sncces-
sirel^ added to the salt, eontinnally abetraet snlphnrie acid, free from
araniam, and tarn the salt black. (Ebelmen.)
Dritd in vaewo 099r •U qfviirM. BbeloMii. Rtninebberg.
2UO 13* .... 70-10 71 -55 .... 68-31
0V^.>.>.M«.....M.M...*M.*.. 4v .••. 3SU 021 ......M Xv 1/ a... Ay w
2H0 18 .... 9-28 9-30
2UQ,SO>-i-2Aq. ... 194 .... 100-00 100-09
Ebelmen found too large a proportion of base and too little acid^
heoause, according to his own statement, the salt was parttallr decom-
posed, even dsring washing. The salt examined by Rammelsoerg lost
9*77 per cent, of water at 220^ Rammelsberg supposes it to contain
d atoms of water.
b, Monostdphate. — Found native as Uranium-vitriol, — I. Formed by
dissolying uranous oxide in boiling oil of vitriol. (RammelBberg). Or
by dissolving green uranoso-uranic oxide in excess of hot oil of vitriol,
diluting the solution with water, and evaporating in vacuo. The uranous
sulphate then crystallizes out, pronded the acid is in considerable excess,
leaving the uranio sulphate in solution. Crystals are still more readily
obtained by mixing the solution of uranoso-uranic oxide in an excess of
sulphuric acid, with water and a small quantity of alcohol, and exposing
the whole in a stoppered bottle to the sun*s rays. The alcohol, which is
itself converted into aldehyde, converts the uranic salt present into a
uranous salt, which then crystallizes on the sides of the vessel. The
clear liquid (which by evaporation and cooling may be made to yield
more crystals) is poured off, and the crystals are dried in the air on
bibulous paper. (Ebelmen.) — 2. A concentrated aqoeoos solution of pro-
tochloride of uranium, treated with sulphuric acid, solidifies in conse-
quence of the separation of crystallized uranous sulphate ; on the applica-
tion of heat, the hydrochloric acid is evolved, and a greenish jelly left,
which is then to be nearly evaporated to dryness, redissolved in water,
and the solution set aside to crystallize. (Peligot.)
a. Bi-hydrated, — This salt forms green crystals permanent in the air.
(Ebelmen.)
0. Tetra-hydraUd, — Crystallizes in ffreen prisms, which are perma-
nent in the air, and belong to the right prismatic i^stem of crystallization.
—-Faces u, i», <, and a; the form is therefore a right rhombic prism, con-
verted by the truncation of the lateral edges into an octagonal prism, in
which the truncation-face m, which replaces the obtuse lateral edge, is
the largest ; acuminated with the four o-faces, of an obtuse rhombic octo-
hedron, resting upon u; the obtuse edges of the latter are truncated by
two faces resting upon m; the more obtuse = 167*' 14' (l(j6° 30' Prevos-
taye) ; «' : « = 1 IS*' 38'. (Rammelsberg.) — (Vide Prevostaye's more ela-
borate description, N, Ann, Chim Phys, 5, 48.)
The salt when ignited leaves black uranoso-uranic oxide. It is
converted, [by more gentle ignition?] in the air, into sulphate of uranic
oxide, with evolution of sulphuric acid vapours. Ignited in a current of
176 URANIUM.
hydrogea gas, it leares nranons oxide free from sulphuric acid. (Ebelmen.)
The crystals, when heated slowly, part with their water. At 200^ they
still retain a sixth part; at 230"^ they lose 21*34 per cent.; and, at a
temperature approacning to redness, the residual portion is evolyed,
together with a small portion of snlpharic acid, so that the loss amounts
to 26-35 per cent. ; the yellow residue, after prolonged Ignition, leares
blackish green uranoso-uranic oxide. (Rammelsberg.)— Water decomposes
the crystals into the insoluble basic salt and a green acid solution.
(Peligot.) The solution absorbs oxygen in the air, and rapidly turns
yellow from formation of uranic sulphate, the precipitated disulphate of
uranous oxide being redissolved at the same time. (Ebelmen.) The crystals
dissolve readily and completely in dilute sulphuric or hydrochloric acid.
(Ebelmen.) If, however, the excess of acid is but small, the solution
becomes turbid by heat. (Rammelsberg.) A small quantity of ammonia
precipitates the disulphate from an aqueous solution ; a larger addition
of ammonia throws down hydrated uranous oxide. (Rammelsberg.)—
Concentrated sulphuric or hydrochloric acid dissolyes the salt but very
sparingly, and consequently precipitates it from an aqueous solution in
the crystalline form. (Ebelmen, Rammelsberg.)
I
UO
SO*
a
68
40
18
• •••
• •«•
• •••
53-97
31-74
14-29
Ebdmeo.
53-02
31-85
2HO
1513
tJO .
SOS .
4HO.
U0,S0» + 2Aq
P
68
40
36
. 126
• •••
• >••
• «••
• •••
47-22
27-78
25-00
10000
Peligot.
46-3
29-7
240
10000
Rammelsberg.
4619
27-91
+ 4Ac
1 144
.... 100-00
100*0
Peligot probably allowed his crystals to separate from a solution con-
taining a larger quantity of acid, so that they combined with less water.
In more recent analyses, Rammelsberg found only between 44'98 and
45*81 per cent, of uranous oxide. Every analysis giyes a small deficiency
of uranous oxide and an excess of acid, in consequence of the salt
being crystallized from an acid solution.
E. Sulphate of Uranoso -uranic Oxide, or Uranoso-uranio
Sulphate. — On dissolving green uranoso-uranic oxide in warm oil of
vitriol, and expelling the excess of acid in a platinum crucible, a pale
green mass is obtained, which may be regarded as U'OS 2S0' or as UO,
SO'+UWjSO'. — This salt, when ignited, evolves sulphurous acid, and
leaves pale yellow sulphate of uranic oxide. 2(U'0*, 2SO')=3(U'0',
S0^) + S0'. — It is soluble in water, ^and forms a green solution; this
liquid when boiled, deposits uranous sulphate, which redissolves as the
liquid cools. (Ebelmen.) Alcohol likewise precipitates uranous sulphate
from the liquid, leaving uranic sulphate in solution. (Berzelius.)
Pale green mass, Ebelmen. Or :
UH)< 212 .... 72-6 .... 72 UO,SO».... 108 .... 3698
2SO» 80 .... 27-4 .... 28 U203,SO» 184 .... 63*02
UO,SO» + U*0»,SO« 292 .... 1000 .... 100 292 .... 100*00
URANIC SULPHATE. 177
F. Sulphate of Ueajiio Oxide^ or Ubakic Sulphate. — a. Basic
9ulphate,'^Fonnd native^ according to Berzelius^ in the form of a yellow
powder.
h. MonastdphcUe, — 1. A eolation of uranoso-uranio oxide in oil of
Titnol is diluted with a moderate quantity of water and oxidized by
nitric acid. (Arfvedson.) — 2. An aqueous solution of urauic nitrate is
evaporated to dryness with sulphuric acid ; the excess of acid expelled
by heat; the residue dissolved in water; and the solution evaporated to a
syrupy consistenee, and left to itself for some time, in order that it may
oeposit crystals. (Ebelmeu.) The crystallization is attended with diffi-
culty. Small lemon-yellow prisms (Bucholz) ; sometimes yellow^ some-
times green crystals^ which redden litmus^ even when fully saturated
with onuiic oxide. (Lecanu.)
Calculation. Bucholz. Ebelmen.
U*0» 144 .... 68-25 70 ... 6674
SO» 40 .... 18-96 18 .... 18-60
3HO 27 .... 12-79 12 .... 1466
XJ«09,SO« + 3Aq 211 .... 10000 100 .... 10000
Ebelmen estimates the quantity of water in the crystals not at 3,
but at 8^ atoms. According to his statement, they part with ^ at. water
when exposed to the air for a long time. Possibly, however, a portion
of the syrupy mother-liquid adhered to the salt which Ebelmen examined,
and this liquid afterwards dried up to a crystalline salt.
The crystals when heated to 1 00°, retain only one atom of water,
which begins to escape at 150% and is wholly driven off at 300°;
the residue afterwards absorbs 3 atoms of water from the air.
(Ebelmen.^ When ignited, the crystals leave 64 per cent, of uranoso-
uranic oxide, containing a small quantity of sulphuric acid. (Bucholz.)
When heated to redness in a current of hydrogen gas, the salt yields
water and sulphurous acid, and afterwarcCs hydrosulphuric acid and
sulphur, leaving uranous oxide free from sulphur. (Ebelmen.) An
alcoholic solution of the salt, exposed to the sun's rays, deposits the
whole of the uranium in the form of uranous sulphate. (Bucholz, Ebel-
men.) — One part of the salt dissolves in 0*6 parts of cold water, forming
a thin syrup, and in 0*45 parts of boiling water; in 25 parts of cold,
and in 20 parts of boiling absolute alcohol (Bucholz) ; it dissolves in
0-47 parts of water at 21°, and in 0'28 parts of Wling water. (Ebelmen.)
c. Bisulphate, — IP0',2S0'. — Separates from a sdution of the mono-
acid salt in dilute sulphuric acid, in crystals resembling those of Wavel-
lite. (Berzelius.)
d, TerstUphate. — U*0',3S0'. — Crystallizes from a solution of the
salt b or c, in oil of vitriol. (Berzelius.) — IT Peligot (iT. Ann, Chim,
Phys. 12, 558,) denies the existence of tne two latter salts, inasmuch
as by following the methods of Berzelius, he succeeded only in obtaining,
in the first instance, a yariable compound, which he regarded as a mix-
ture of the monosulphate and acid sulphate; and in the second, a deli-
quescent salt, containing 58*0 per cent, of uranic oxide, 36*9 of sul-
phuric acid and 5*1 of water, which nearly corresponds to the formula
U'0^2S0^H0 (a salt similar in composition to the bisulphate of
potash). The excess of sulphuric acid arises from the impossibility of
removing the whole of the mother-liquid. ^
yoL. ly. H
178 URANIUM.
G. HydroBulphooarbonate of lime forms with uranio salts, a dark-
brown liquid, which gradually becomes tarbid, and deposits a pale
grejish brown precipitate. The latter appears to be a compound of
iistdphide of Carbon with Seequimlphide of Uranium; the solution, how-
eyer, continues yellow. (Berzelios.)
Uaanivm ahd Bouarauif.
Sbi«imitb of Uranio Oxidb, or Ubanio Sbxjekitb.— a. Mono^
se{0Ai<tf f — Lemon-colonred powder, which is converted by heat into
green uranoso-nranic oxide, with loss of selenioos acid and oxygen gas.
b. Acid telenite f — Prepared by dissolving a in an aqueous solution
of selenious acid. When imperfectly dried^ it is transparent and of the
consistence of varnish ; in the anhydrous state it is white, opaque, and
crystalline. Soluble in water. (Berzelius.) Its formula, according to
Muspratt, is U»0', 3SeO*.
Ubaniuh and Iodinb.
A. Pboto-iodidb op Ubakivm and Hydriodatb of Ubakovs
Oxide. — Hydrated protoxide of uranium yields with aqueous hydriodic
acid, a dark green solution containing free hydriodic acid. When spon-
taneously evaporated, the solution turns brown and evolves free iodine,
leaving a black crystalline mass, which contains a small quantity of
sesqui-iodide of uranium, and dissolves in water^ forming a brownish-
red solution. (Rammelsberg.)
B. loDATB OF Ubanous OxiDE; Or Ubakous IoDATE.**Todate of
soda gives with protochloride of uranium, a pale green precipitate which
is soluble in an excess of the latter salt. The precipitate, 17 allowed to
remain immersed in the liquid, is converted, after some time, into white
iodate of uranic oxide^ of which a portion dissolves, together with free
iodine in the solution, and colours it yellow. (Rammelsberg.}
C. loDATB OF Ubantc OxtDB, or Ubanic Iodate. — Iodic acid and
iodate of potash produce in a solution of uranic nitrate, a white preci-
pitate, soluble in a large quantity of water. (Pleischl.) The salt, which
is yellowish white when dried, gives off part of its water of crystal-
lization at the temperature at which decomposition commences; it then
evolves iodine and oxygen gas, and leaves nranoso-uranic oxide. It
gives up its acid to potash, and dissolves with some difficulty in nitric
acid. (Rammelsberg.)
Cslcubition. Rammelsbefg.
U«0« 144 .... 40-66 40-13
IO» ., 166 .... 46-76
ftHO 45 .... 12-68
U«0»,I0* + 5Aq 865 .... 100-00
Periodate of potash gives with protochloride of uranium, a greyish
green precipitate of Periodate of Uranous oceide, which, after some time, is
converted into yellowish white periodate of uranic oxide; the latter
dissolves in the liquid on the application of heat. (Rammelsberg.)
URANIC BROMATE. 179
Uranium and Bromine*
A. Ppotobromidb op Uranium. — Bydrated, or Hydro^omaU of
Uranom oxide. — The dark green solution of hydrated uranous oxide in
aqaeoos hydrobroniic acid, evaporated over oil of vitriol, yields ill-defined
dark green crystals, and dries up to a highly deliquescent saline mass.
The aqueous solution gives ojQT hydrobromic acid when heated, and deposits
a fine black powder, probably consisting of uranous oxide. (Rammelsberg.)
tJ ....
Br ....
4H0
CalonlatioD.
Rtmrnekbari:.
600 .... 34*40
34-43
78-4 .... 44-96
36*0 .... 20-64
^b»
UBr,4Aq 174-4 .... 100-00
B. Bromibb of Uranous Oxidb and Monobtdrobromatb ov
Uranic Oxidb. — 2U0,Br and U'0',HBr. — By boiling uranous oxide with
bromine and water, or by dissolving uranic oxide in aqueous hydro-
bromic acid, a colourless solution is obtained, which turns yellow when
eraporated, and yields flat yellow needles having a strong styptic taste.
When dried at a high temperature, these crystals assume an orange colour
and evolve hydrobromic acid; at a red heat, they evolve bromine and
leave uranic oxide (uranoio*nranio oxide). They deliquesce in the air ;
ammonia precipitates uranio oxide from their solution, ^Berthemot, Ann.
Chim, Fhy$. 44, 387.)
The green mixture of protochloride of nraninm and bromate of potMh
immediately turns yellow, from formation of sesqulbromide of nranoat
oxide and separation of free bromine. (RammelBberg.)
G. Bromatb of Uranio Oxidb or Uranic Bromatb.— When mono-
sulphate of uranic oxide is precipitated by bromate of baryta in equivalent
proportions, and the yellow filtrate allowed to evaporate under a bell-jar
oyer oil of yitriol, a clear nncrystallizable syrup remains, which, on
exposure to the heat of a water-bath, evolres a considerable quantity of
bromine, and then solidifies. The mass dissolves in water, with the excep-
tion of a small quantity of a brown powder; the solution again evaporated
and digested in water till the residue dissolves completely, yields, on
evaporating the solution and drying the residue under a receiver over oil
of vitriol, a yellow pulverulent salt. The latter when heated out of
contact of air yields water, oxygen gas, vapour of bromine, and a yellow
residue containing bromide of uranium [dilnromide of uranous oxide)] and
when ignited in the air^ leaves uranoso-uranio oxide. (Rammelsberg,
Po^g. 55, 77.)
The yellow »ali. Approximate calculation* Rammelsberg.
4U*0» 6760 .... 53-57 ........ 53-77
3BrO« 355-2 .... 33-03 32-23
16HO 1440 .... 33-40 1400
4U«0«,3BrO» + 16Aq.... 1075-2 .... 100-00 ........ 10000
v2
180 URANIUM.
Uranium and Chlorine.
A. Three-fourths Chloride op Uranium. — Formed by paasing dry
hydrogen gas over protocbloride of uranium heated in a tube till it nearly
Yolatilizes^ as long as hydrochloric acid continues to be formed.
4UC1 + H =U^P + HC1.
Dark brown mass, of coarse fibrous texture, and but slightly Tolatile.-^
Dissolves very readily in water. The purple solution is converted in a
few moments — ^with evolution of hydrogen gas and separation of a red
powder, which is probably an oxide of uranium — into a green solution of
protocbloride of uranium. (Peligot.) [The behaviour of the aqueous
solution, prepared as above with ammonia is described with the suboxides
of uranium, (p. 159).] According to Rammelsberg, the same chloride
of uranium is obtained by jgniting the protochlotide in ammoniacal gas.
Calculation. Peligot.
4U 240-0 .... 69-33 691
3C1 106-2 .... 30-67 30-6
U*C1» 346-2 .... 100-00 997
B. PiiOTOcnLORiDE OF Uranium. — Dry hydrochloric acid gas has no
action on uranous oxide at a red heat. — Uranium bums in chlorine gas with
vivid incandescence, yielding protocbloride of uranium. — Preparation,^^
Dry chlorinis gas is passed over an intimate mixture of charcoal and either
of the oxides of uranium heated in a very refractory glass tube. The heat is
applied gently at first, in order to expel the moisture, and the chlorine is
made to pass slowly through the tube ; but afterwards the heat is greatly
inreased, and the chlorine made to pass over in larger quantities. The chlo-
ride of uranium which volatilizes in red vapours, in company with carbonic )
acid and chlorine gas, condenses in the tube not far from the heated portion.
The tube is then fused between the chloride of uranium and the charcoal,
and likewise at the other extremity. (Peligot.) The quantity of charcoal
should not exceed one-fourth the weight of the uranoso-uranic oxide; the
chloride of uranium, which for the most part condenses close to the
mixture, is then Contaminated with but a small quantity of charcoal.
Where the chlorine first comes in contact with the mixture, large acicular
crystals of chloride of uranous oxide are formed. (Rammelsberg.)
Chloride of uranium crystallizes in dark green regular octohedrons,
which have the metallic lustre; and, when heated to redness, volatilize in
red vapours and sublime. (Peligot.)
Calculation. Peligot {mean), Rammelsberg.
U 60-0 .... 62-89 61 14
01 35'4 .... 37-11 37-86 .... 35-983
UCl 95-4 .... 100-00 99-00
Peligot obtained, as the average of six analyses, 71 '333 per cent, of
uranoso-uranic oxide; if this be estimated as UM3^ it gives 280 : 240 =
71*333:61*14; consequently 61*14 of uranium, and not 62*9^ as in
Peligot*s calculation.
; URANIUM AND CHLORINE. 181
I
HydraUd Chloride of Uranium or Mono-hydrochloraU of Uranotis
Oxide.-^l, Protochloride of oraniam when exposed to the air emits a
cload of hydrochloric acid, and still more powerfully on the addition
of water^ becaase a rise of temperature is thereby produced : it is very
easily soluble in water. (Peligot.)
Dissolves in water with a hissing noise. (Rammelsber^.) The dark
emerald-green solution loses a considerable quantity of hydrochloric acid
when eraporated, and leayes an amorphous resicuie, which is perfectly
soluble in water, and, when strongly ignited in an open yessel, is converted
into nranoso-nranic oxide. When evaporated in vacuo, the solution also
leaves a green, uncrystallizable, resinous, deliquescent mass, different from
protochloride of uranium. (Peligot.)
The green solution of protochloride of uranium turns brown when
boiled and evaporated, giving off hydrochloric acid and depositing a very
fine black powder, which passes through the filter, and appears to consist
of uranous oxide: the brown colour is retained for twenty-four hours;
ammonia precipitates hydrated uranous oxide from the brown as well as
from the green solution. (Berzelius.) The hydrate, on being washed in
the air, is converted into hydrated uranoso-uranic oxide. (Rammelsberff.)
—2. An ethereal soiutiofi of hydrochlorate of uranic oxide exposed to uie
direct rays of the sun, becomes colourless and deposits hydrochlorate of
uranous oxide in green flakes, which unite into a blackish green unctuous
mass, and dissolve with the same colour in water. (Gehlen, A. Gehl.,
3, 569.)
G. Hydrochloratb of Uranoso-ubanic Oxide. — Concentrated
hydrochloric acid forms with green uranoso-uranic oxide a bottle-green
solution, which becomes paler in the air, in consequence of the formation
of a uranic salt, and dries up to an uncrystallizable mass. (Arfvedson.)
D. Chloride op Uranous Oxide.— Pe%o<'« Chloride of Uranyl. —
When dry chlorine gas is passed over uranous oxide at a red heat, the
tube becomes filled with an orange-yellow vapour of chloride of uranous
oxide. (Peligot.)
2U0 + CI = 2(U0),CI.
If the protoxide contains any uranoso-uranic oxide, sesquioxide of
uranium remains behind on dissolving the compound. (P-eligot.) — Chloride
of uranous oxide is yellow, crystalline, readily fusible, and apparently not
very volatile. — When heated with potassium, it is resolvea into chloride
of potassium and uranous oxide :
2U0,Cl + K « 2U0 + KCl.
It is highly deliquescent. (Peligot.)
CalciUatioii. Pdij^t (mean).
2U0 1360 .... 79-34 79-6
CI 35-4 .... 20-66 20-4
2U0,a 171-4 .... lOO'OO 100-0
This compound mar be regarded: (1) with Peligot, as IPO* + CI, that
is to say as chloride of uranyl; (2) with Berzelius, as 2U'0^UH!]!1', eras a
compound of 2 atoms of uranic oxide with one atom of sesquicfaloride of
uranium j (3) as UK)^!!, or as uranic oxide in which the third atom of
182 URANIUM.
oxygen is repla^d by oblorine. A( all eventSi ibis <K>mpoaDd i« analogous
to COCl, S0»C1, and CrO'Cl.
£. MoNO^HYDEOOHLORATB OF Uranio Oxxde. — 1. Prepared by dis
solring chloride of aranoua oxide in water :
U«0*C1 + HO = U»0>,HC1.
-^2. Hydroohlorate of uranoua or uranoso-nranio oxide is oxidized by
63nK>sare to the air, or by nitric acid. — According to Klaprotb, the yellow
solution yields, on OTaporation, yellowish green crystals, which effloresce in
the air, and are readily soluble in water, alcohol, and ether, and appear
to be oblique four-sided tables. According to Lecanu, the solution yields
a few yery deliquescent needles, which scarcely redden litmus. According
to Arfvedson, the solution dries up to an uncrystallisable, highly deli-
quescent syrup.
F. CHLOBATa ov Ub ANGUS OxiDB or Ubanous Chloratb. — The
green solution of hydrated uranous oxide in aaueous chloric acid decom-
poses spontaneously (very quickly when heate<h, chlorine being evolved,
and the liquid assuming a yellow colour, from formation of hydroohlorate
of uranio oxide. (Rammelsberg.)
G. Perohjumatb ap Ubanous Oxidb. — The dark green solution of
the hydrate in aqueous perchloric acid cannot be evaporated to dryness
either over oil of vitriol or over a water-bath, because it is thereby partially
eonverted into hydroohlorate of uranio oxide. (Rammelsberg.)
Ubanium and Fluobinb.
Fluobidb of Ubanium and Hydbopluatb of Ubanio Oxide. — The
yellow solution of uranic oxide in aqueous hydrofluoric acid yields on
evaporation a white, amorphous, pulverulent crust, which creeps up the
sides of the containing vessel : after being completely dried, it redissolves
in water without change. With alkaline fluorides, fluoride of uranium
forms yellow crystallizable compounds soluble in water. (Berzelius, Poyy.
1. 34.)
Ubanium and Nitbooen,
•
A. Nitrate of Ubanic Oxide or Uranic Nitrate. — a. Basic nitrate.
— Formed by gently heating the normal salt till it assnmes an orange-
yellow colour, after which the still undecomposed mononitrate (together
with a small quantity of basic salt) is removed by washing with water.
— Yellow powder insoluble in water containing 92 of oxide. (Bucholz.)
Orange-yellowy leaves when ignited first U'O*, and then U*0*. (Peligot.)
5. J/onon/fra^f.— Uranous, uranoso-uraniu, or uranic oxide is dissolved
in dilute nitric acid, and the solution evaporated to the cirstallizinff
point. [For Peligot*s and £belmen's mode of preparation, via. p. 163.1
— The salt crystallises in lemon-yellow prisms (BuchoU) with a tinge of
green ; the crystals redden litmus. (Lecanu.) Crystalline system, the right
prismatic. — Form: rectangular prism {m- and ^faoes) acuminated with
the a-&ces of a rhombic pctohedroUi the apex replaced by the p-face»
URANIUM AND NITROGEN. 183
a :m s IW; a : ^ = lie^" 3tf. (Haberle, A. GM. 4, 146.) Also with the
p-hcea. a : <= 116°3C;t :<= 12r 20'j» : ni=120°45'; i :i s= 117°20';
a : rt = 127. (Prevosta-je, ^. Ann, Ckim, Fhys. 5, 48.)
UW
NO*
6H0
CalonUtioii.
Peligot.
KUhn.
1440 .... 67-14
57-05
...»
58-57
54-0 .... 81-43
21-46
.(•i
21-38
540 .... 21-43
22-50
252-0 .... 100-00
101-01
U«0",N0» + 6Aq 252-0
The crystallized salt remains unaltered ia the air at temperatnres
between 15^ and 20^. fLecanu.) In a warm dry atmosphere it effloresces
to a yellow powder (Dncholz) ; also in racuo, with loss of 3 atoms of
water. (Peligot.) When heated, it melts in its own water of crystalliza-
tion, gives off water and acid, and acquires a reddish yellow colour,
and when heated to redness, is converted into uranoso-uranic oxide.
(Buoholz.) If the salt be fused at a gentle heat, till the greater part of
the water is expelled, a yellow liquid remains, which, on cooling, soli-
difies in transparent nrisms; and these, when exposed to the air, rapidly
absorb water and lose their transparency. (Peligot.) According to
Arfvedson, the salt evolves oxygen when moderately heated and is con-
verted into nitrite of uranic oxide, which, at incipient redness, is
decomposed into nitrous acid gas and uranoso-uranic oxide, without the
intermediate production of pure uranic oxide. The salt fuses on ignited
charcoal and then detonates like nitre. (Lecanu.) An alcoholic solution,
heated to a temperature of 38°, evolves heat spontaneously, boils with
the greatest violence, gives off nitrous ether, and deposits a very large
quantity of a lemon-yellow powder, which appears to be nearly pure
uranic oxide. (Bucholz ; see also Malaguti, p. 168.) When a solution of
uranic nitrate in sulphuric ether is exposed to sun-light, nitrous ether
is produced, a large quantity of uranic oxide deposited, and there remains
an aqueous solution coloured green by a salt of uranous oxide. (Bucholz.)
The salt dissolves in half its weight of cold water, forming a greenish
yellow solution ; it deliquesces in a moist atmosphere. It is also soluble
.m 0*3 parts of absolute alcohol, and dissolves readily in sulphuric ether.
(Bucholz.)
c. TemUrate.—\J^G*, 3N0^— This salt cirstallizes with ^eater
facility, and is less soluble in water than b ; it likewise effloresces in the
air. (Berzelius.) Accordiug to Lecanu, a solution of uranic oxide in
excess of nitric acid, yields on evaporation a beautiful green, amorphous
mass, which deliquesces in the air. According to Ebelmen, there is no
salt containing more than one atom of NO^ to one atom of IT'O*.
IT This statement is also confirmed by Peligot, (i\r. Ann. Chim. Phyz, 12,
557,) who succeeded only in obtaining the ordinary nitrate with 6 atoms
of water. IT
B. Uranatb of AMMONiA.-^Precipitated in the hydrated state as a
yellow powder, on mixing hydrochlorate or nitrate of uranic oxide with
excess of ammonia. The salt remains unchanged even at temperatures
above 100°, but when exposed to a stronger heat, it gives off nitrogen
gas, ammonia, and water, and is converted into uranous oxide. Does
not dissolve in excess of ammonia. (Arfvedson.) Sparingly soluble in
pure water, but insoluble in water containing sal-ammoniac (Berzelius.)
184 URANIUM.
— Contains 90 per cent, of uranio oxide. — Cannot be freed from ammonia
by boiling with water. — Dissolyes in sesqnicarbonate of ammonia^
forming a solution of the following salt D. (Peligot.)
C. Carbonate op Uranous Oxide and Ammonia. — Uranaao-
amnionic Carbonate, — Carbonate of ammonia gives with uranous salts a
dark green precipitate, which dissolves in an excess of the precipitant,
forming a dark green solution. The solution, evaporated at a gentle
heat, evolves carbonic acid, and deposits first hjdrated uranous oxide,
and then uranat'O of ammonia. (Rammelsberg.) The pale green preci-
pitate which ammonia produces in a solution of nranoso-uranic sulphate
likewise dissolves in excess of the former, producing a pale green solu-
tion. This liquid, when heated, deposits the nranoso-uranic oxide free
from carbonic acid. (Arfvedson.)
D. Carbonate op Uranic Oxide and Ammonia. — Urano-ammonic
Carbonate. — a. NetUral Salt, — Carbonate of uranic oxide, or uranate of
ammonia, is dissolved in a warm aqueous solution of sesquicarbonate of
ammonia and the lemon-yellow filtrate left to cool till it crystallizes
(Berzelius) ; or the solution is spontaneously evaporated. (Lecann, Peligot.)
— Ebelmen digests an excess of uranate of ammonia with carbonate of
ammonia at temperatures between 60^ and 70°, filters warm, and sets
the solution aside to crystallize. The uranate of ammonia which remains
undissolved, may again be treated with the mother-liquid. Delifs {Pogg,
55, 229,) agitates the uranate of ammonia for some minutes in a
stoppered bottle, at a temperature of 35°, with a concentrated solution of
carbonate of ammonia; filters, without diluting the filtrate with the
wash- water, and sets aside to cool.
Crystallizes in lemon-yellow transparent prisms, which are permanent
in the air. (Berzelius, Lecanu, Peligot.) — Sulphur-yellow and opaque.
(Delffs.) Crystalline system, the oblique prismatic. Fig. 85, with the
wi-face; the /-face larger; a :^ = 138° 45'; «:tt = 150''; i:<=90°;
* :/ backwards = 96'; t:v}=z 132° 30'; «':»!= 137^ 30'; t*M w =
95°; m : ^ = 90°. (Prevostaye, X^. Ann. Chim. Phy$. 5, 49.)
CrjfBtaUixed,
2NH» 34 .... 12-98 ...
U*0» 144 .... .M-96 ....
3CO« 66 .... 25-19 ....
2H0 18 .... 6-87 ...
2(NH*0,C02) + U«O*,C0« 262 .... 10000 .... 10071 .... 100-00 .... 100-00
Column a is the analysis by Ebelmen and Delffs of the salt dried
in the air at ordinary temperatures ; but as Delffs found that the latter
lost 3 per cent, at 100°, and regarded the loss only as water, he calculated
the analysis 6 accordingly.
The salt may be preserved in stoppered bottles, which, however, when
opened, emit a smell of carbonate of ammonia; also in atmospheric
air containing a small quantity of carbonate of ammonia vapour. In
the open air it is very slowly decomposed, acquiring at the same time a
slight orange colour. At 100°, it suffers a considerable loss of weight in
a few hours ; between 200*^, and 250^^ it rapidly evolves water and car-
bonate of ammonia, and acquires an orange colour. The last portions of
Bbolmen
Ddffs.
•
a.
h.
12-63
..»•
11-33
....
11-80
54*89
•.«.
55-47
....
57-19
25-43
....
23-98
....
24-72
7-76
....
9-22
....
6-29
URANIUM AND NITROGEN. 185
earbonaid of ftmmonia are expelled with difficulty; but by prolonged
beating, at a temperatnre of 300% a residue of pure, brick-red uranio
oxide is obtained. When rapidly heated in close yessels, the salt leayes
protoxide of uranium, which, if exposed to the air immediately after
oooling, takes fire and bums to green uranoso-uranic oxide. (Ebelmen.)
When heated it giyes off carbonate of ammonia, and leaves, first, car-
bonate uranio oxide, and then green uranoso-nranic oxide. (Peligot.) —
The salt dissolves in 20 parts of water at 15% and more abundantly in
water containing carbonate of ammonia (Ebelmen); it is insoluble in
pure water, but dissolves in water containing carbonate of ammonia.
(Benelius.) The solution, on being boiled, evolves carbonate of ammonia
and becomes turbid, gradually depositing the compound b ; nevertheless,
a portion of uranium remains undissolved. (Arfvedson.) The aqueous
solution is turned brown by hydrosulphate of ammonia, but not till after
a considerable lapse of time. (Wittstein.)
6. With a very large excess of Uranie oxide ?— 1 . The pale yellow
precipitate, which appears on boiling an aqueous solution of the preceding
salt a. On washing the precipitate, the water takes up a portion of the
nranic oxide, which is acain precipitated as it mixes with the saline
liquid previously passed through the filter. (Arfvedson.)— According to
Arfvedson, the compound contains uranie oxide with a small quantity
of ammonia and carbonic acid; according to Peligot, it is uranate of
ammonia ; according to Ebelmen, it is hydrated uranio oxide, still con-
taining 2 per cent, of ammonia, but no carbonic acid. — 2. On preci-
pitating nitrate of uranie oxide with carbonate of ammonia, not in excess,
a yellow precipitate is obtained, which becomes lighter when washed,
and at last dissolves sparingly, forming a yellow solution: this solution,
when boiled, becomes yellow and milky, from separation of uranie oxide.
—The above precipitate dissolves in acids with effervescence ; but when
heated alone, evolves water, carbonic acid, and nitrogen gas, the latter
arising from decomposition of ammonia. (Berzelius, Fogg. 1, 361.)
E. Sulphate of Uranous Oxids and Ammonia.*— CTranoao-ammo-
nic sulphate, — Ciystallizes in small dark green needles, united together
in rounded masses and easily soluble in water. The solution when heated
becomes turbid, from separation of basic salt ; when boiled with potash,
it gives off ammonia and deposits uranous oxide. (Rammelsberg.)
CryttalHzed.
Rammelsberg.
NH»
17
9-77
9-09
UO
68
.... 39-08
41-73
2SO»
80
.... 4598
4315
HO
9
5-17
NH<0,SO»+UO,SO»
. 174
.... 10000
As the salt analyzed was mixed with portions of the following
compound, the analysis does not quite accord with the calculation.
(Rammelsberg.)
F. Sulphate of Uranic Oxide and Ammonia. — Urano-ammonic
Sulphate, — Formed by mixing sulphate of uranio oxide with sulphate of
ammonia, and evaporating the solution to the crystallising point. (Arfved-
son.) The salt belongs to the oblique prismatic system. (Fig, 102, without
the faces a and h^ and without the two faces between i and f) ; « : ^ = 1 37*
186 URANIUM*
to 188^; *:t* = 103^30'; u:<=109^40', &c. (Preyottajt, If. Ann.
Chim. Pkyu. 5, 51.) When heated to rednefla. It leaves uraaoso-uranic
oxide; it i» readily iiolabU iu water. (Arfredson.) Sparingly soluble.
(Peligot.)
€fry$iaUwed. P«ligot,
NH» ^ 1 7 .... 6-34
U«0> 144 .... 53-73 53*7
2S0» 80 .... 29-85 29-8
3H0 27 .... 10-08
NH*0,SOa+U«0»,SOa + 2Aii. 268 .... 10000
G. AMMONio-cHLOitiDE OF Uranium. — 100 parts of protochloride
of uranium at ordinary temperatures, absorb 5*44 parts of ammoniacal
gSLB, the action being attended with evolution of heat. (Rammelsberg.)
Calcalation.
NH9 17-0 .... 6-61
3UCI 286-2 .... 94-39
8UC1,NH» 303-2 .... 10000
H. Chloride of Urangus Oxidb and Ammonium^ or Hydro-
CHLORATE OF Urajnio Oxide AND Ammonia. — Poligot's Ammonto-
chhride of Uranyl, — ^An aqueous mixture of sesqui-chloride of uranium
and salammoniac eyaporated to a syrupy consistence, yields, after long
standing, highly deliquescent rhombohewd crystals. (Peligot.)
CalcHlation, aooording to Pdigot.
a. Or : d.
NH* 18-0 .... 7-41 NH» 170 .... 700
U'C 136-0 .... 56-02 U'O* 1440 .... 59-31
2C1 70-8 .... 29-16 2HC1 72-8 .... 2998
2HO 18-0 .... 7*41 HO 90 .... 3-71
242*8 .... 100-00 242-8 .... 100*00
According to a, NH*Cl+U«0»,Cl,+2Aqj according to 6, NH»,HC1
+ U*0»,HC1 + Aq.
Uranium and Potassium.
Uranoso-uranic oxide heated with potassium forms a mass which
inflames spontaneously in the air. (Berzelius.)
A. Uranate of Potash. — 1. Precipitated on mixing a salt of
uranic oxide with excess of potash, in the form of a light orange-Yellow
powder, which, when ignited, loses water and becomes yellowish red.
(Arfvedson.) — 2. Likewise formed by fusing uranic oxide with excess of
carbonate of potash, and removing the latter by water. (Berzelius.) —
3. Remains in the form of a brick-red powder after igniting the double
carbonate of uranic oxide and potash and exhausting with water. (Ber-
zelius.) — 4. By igniting the double acetate of uranic oxide and potash.
(Wertheim.)
Calculation. Berzelias. Wertheim.
KO 47-2 .... 14-08 12-8 13 99
2U«0» 288-0 .... 85-92 86-8 85-73
K0,2U»0» 335-2 .... 10000 ~., 99^6 ~.. 9972
URANIUM AND POTASSIUM. 187
When this salt ia heated to redness in an atmosphere of hydrogen gas,
it is partially redaced, and a mixture is formed consisting of uranoso-
nranic olide, and uranate of potash containing a larger proportion of
base. The latter compound is insoluble in water, but dissolves in hydro-
chloric acid, which leaves the uranoso-uraoio oxide so finely divided.that
it passes through the filter. (Berzelius.)
B. Carbonate op Uranic Oxidb and Potash. — Uranopotamc
CarboncUe. — The uranic oxide precipitated by pure potash or its carbonate,
dissolves in an aqueotfs solution of carbonate of potash, but more readily
in the bicarbonate, forming a yellow solution, from which the double salt
separates in lemon-yellow crystals, or as a crystalline crust. (Chevreul.)
— Uranic oxide precipitated by caustic potash is insoluble in mono-
carbonate of potash, but dissolves completely in bicarbonate, when
digested with it; on evaporating the pale yellow solution at a gentle
heat, a lemon-yellow crust is obtained, which may be purified by 'a
second crystallization. (Ebelmen.)
2KO
ICttlonlation.
94-4 .... 31*01
1440 .... 47-31
66*0 .... 21-68
Ebelmen.
3M2
XJK)»
SCO*
HO
47-13
2183
0-40
2(K0,a
y) + u«o«,co»
304-4
.... 100-00
100-48
At dOO^, it gives off carbonic acid, and assumes an orange-yellow
o#lour from formation of uranate of potash. (Ebelmen.) After ignition,
it leaves a brick-red mixture of uianate and carbonate of potash.
(Berzelius.)
2[2(KO,CO«) + (JP<y,CO*)^ = 3(K0,C0«) + KO,2U20» + 3C0«.
Dissolves without decomposition in 13*5 parts of water at 15^ and in a
smaller quantity of hot water, forming a lemon-yellow solution. — A solu-
tion of one part of the salt in 833 parts of water still exhibits a deep
yellow colour; in 1332 parts, a pale yellow; in 2664 parts, still paler; in
5328 parts, a mere tinge of yellow; and with 1 0,656 parts, it is colourless;
the latter solution however is rendered turbid by potash, and after a few
hours deposits orange-yellow flakes of uranate of potash.
Boiling water, when quite free from potash, dissolves the salt with
partial decomposition and separation of uranate of potash; the latter
compound is also deposited after some time from a cold solution when very
dilute and not containing an excess of carbonate of potash. Caustic
potash precipitates the whole of the uranic oxide from the solution, in the
form of uranate of potash, even if a large excess of carbonate of potash
is present. Acids if not added in excess, produce the same light yellow
precipitate as is produced by carbonato of potash in a salt of uranic
oxide. The double salt is perfectly insoluble in alcohoL (Ebelmen.)
C. Sulphate op Uranous Oxide and Potash. — Uranoso-potame
Sufphate. — A solution of sulphate of potash and sulphate of uranous oxide
yields, when spontaneously evaporated, a green crystalline crust, which is
difficultly soluble in water, and at a temperature below redness, evolves
sulphuric and sulphurous acids, and leaves the uranium in a higher state of
oxidation. (Rammelsberg.)
188 URANIUM.
Calcolttioii. Rammelfiberg.
KO 47-2 .... 15-12 15-29
2UO 136-0 .... 43-56 44-21
3SO» 120-0 .... 38-44
HO 9-0 .... 2-88
KO,SOa + 2(UO,SO») + Aq.... 3122 .... 10000
D. SuLPHATB OF Uranoso-uranic Oxidb AND PoTASH. — ^Grevish-
green powder which is nearly or quite insoluble in water. (Berzelius.)
•
' E. Sulphate OF Uranic Oxide and Potash. — Urano-potassic Sul-
phate. — An aqueous mixture of sulphate of uranic oxide and sulphate of
potash is eyaporated to the crystallizing point, and the double salt purified
by re-crystallization. (Arfvedson.) Lemon-yellow, crystalline/ granular
salt. (Anvedson.) Not octohedraL (Berzelius.) Forms warty crystalline
masses. (Peligot.) Crystalline crust, permanent in the air. (Ebelmen.)
Benelias.
/ '^ »
Cry$talUxed. Ebdmeii. a. b,
KO 47-2 .... 16-32 .... 1664 .... 15-833 .... 14-60
XJ«0» 144-0 .... 49-80 .... 4890 .... 52-833 .... 50*84
280» 80-0 .... 27-66 .... 2777 .... 27*834 .... 28*20
2H0 18-0 .... 6-22 .... 652 .... 3-500 .... 6-50
K0,S0» + U«0»,80» + 2Aq. 2892 .... 100-00 .... 99 83 .... 100000 .... 100-14
The salt h examined by Berzelius was crystallized from a solution
containing excess of acid. Arfvedson found in the anhydrous salt 13-26
per cent, of potash, 58-06 of uranic oxide, and 28*68 of sulphuric acid.—
Alcohol remoTCs from this salt one-fifth of the uranic sulphate (Ber-
zelius.)
The crystallized salt gives off its water when heated (at 120^ entirely,
Ehelmen) and fuses completely at a red heat; on cooling, it appears greenish
yellow, but is yery little decomposed (according to Ebelmen, not at all);
it likewise redissolves in water, forming a pure yellow solution. (Berzelius.)
This salt dissolves in 9 parts of water at 22^, and in 5-1 parts of
boiling water. Ammonia or hydrosulphate of ammonia added to the
solution throws down uranic oxide still containing potash. (Ebelmen.)
Alcohol does not dissolve the double salt, and precipitates it from an
aqueous solution. (Berzelius.)
F. Chloride of Uranous Oxide and Potassium. — Called Chloride
of IJranyl and Potamum by Peligot (who first demonstrated the existence
of oxygen in this compound). — By heating the hydrated crystals (vid,
infra) to a temperature somewhat above 100°, the anhydrous compound
IS obtained. — The latter fuses at an incipient red heat. (Arfvedson.)
When heated with potassium, it is resolved with vivid incandescence into
uranous oxide and chloride of potassium. (Berzelius.) When ignited in
hydrogen gas, it swells up, and isconyerted, with formation of hydrochloric
acid, into a dark opaque mass. It is not however completely decomposed,
even after being submitted to the action of hydrogen for many hours, so
that water, though it leaves uranous oxide, nevertheless dissolves out a
tolerably large quanti^ of protochloride of uranium together with the
chloride of potassium. When heated above the fusing point, it is partially
decomposed, turning green and evolving chlorine. (Arfvedson.) When
URANIUM AND SODIUM. 189
Btrongly ignited, it leayes fiued chloride of potaflmam, in wbicli brilliant
crystalline scales of uranoos oxide are seen to float. (Peligot.)
Ka + 2U0,a = KCl + 2U0 + CI.
Bydraied Chloride of Uranous Oidde and Fotasrium, or Hydrocklorate
of Vranic Oxide and Potash. — An aqneons mixture of sesani-chloride of
nranium and excess of chloride of potassium is eyaporatea to the crys-
tallizing point. — If the latter does not predominate, the double salt
crystalUzes with difficulty; as however the double salt and chloride of
potassium crystallize with about equal facility, the two kinds of crystals
must be picked out one from the other. (Arfvedson.) Peligot recom-
mends the addition of a large excess of hydrochloric acid to the mixture,
previous to evaporation. The double salt crystallizes in lemon-yellow,
oblique fouiHBided prisms and rhombic tables. Crystalline system, the
doubly oblique prismatic. Fig. 129, without the vry v-, and 2-faces; y : q
= 119^ 45'; y : d = 124^ 30'; y : « = 133° 5'; d:k below = 136° 30';
e : s below = 143°, &c. (Prevostave, iV. Ann. Chim. Phys. 6, 165.) Parts
with its water a little above 100 . Dissolves very readily in water; but
the solution, when evaporated, yields crystals of chloride of potassium,
while sesquichloride of uranium remains dissolved. (Peligot)
Cry$iatt%zed. Peligot.
K I........ 39-2 .... 14-85 13-95
2U0 136-0 .... 51-51 . . 50-47
2Cl 70-8 .... 26-82 26-75
2HO 180 .... 682 7-30
KCl,USOSCi -I- 2Aq. 264 .... 10000 iZI 98-47
== K0,HCl4-IP0',HCl. Arfvedson found that the crystals contained:
potash 17'37> uranic oxide 35*65, hypothetical anhydrous muriatic acid
20-50, and water 6*49 per cent.
Uranittm and Sodium.
A. Uranate of Soda.— Remains on igniting the double acetate of
uranic oxide and soda. Colour, pure yellow. Contains one atom of soda
with 2 atoms of uranic oxide. (Wertheim.)
B. Carbonate op Uranic Oxidb and Soda.-^ Urano-sodic Cat^bonate,
— The uranic oxide precipitated by carbonate of soda dissolves in an
excess of the soda-sait, forming a yellow solution. By evaporating a
solution of uranate of soda in a warm aqueous solution of bicarbonate of
soda, Ebelmen obtained a crystalline crust.
Uranoso-uranic or uranic oxide does not dissolve in carbonate of soda
before the blowpipe on charcoal, but imparts to a large quantity of the
carbonate— -inasmuch as uranate of soda is formed and diffuses itself through
it — a yellowbh-brown colour '(which remains even in the reducing flame).
If too large a quantity of the alkaline carbonate is used, the oxide sinks
into the pores of the charcoal, without undergoing reduction. (Berxelius.)
C. With borax in the inner flame, uranic oxide is reduced to uranous
oxide, yielding a dull green glass, which, if it contains a sufficient quantity
of the protoxide, is bhM^ened by gentle flaming; in the outer flame on
platinum, a dark yellow glass is obtained. (Beraelius.)
190 URANIUM.
D. IT Pthophosphatb of Uranic Oxibb and Soda. Prepared bj
Persoz {Ann. Fharm., 65, 163).— -Tbia nit baa a pure jellow cofoar, and
is very soluble. Tbe solution may be evaporated to tne consistence of a
thick gum without crystallizing. It is not decomposed by bydrosulphuric
acid or bydrosalpbate of ammonia. IT
£. With microcosmic salt in tbe iuDor flame, a beautiful green glass is
obtained, especially after cooling; in the outer flame, on platinum, a glass
which is yellow wnile hot^ and becomes pale greenish-yellow on cooling.
(Berselius.)
Uranium and Barivm.
Uranate of Baryta. — 1. Formed when a boiling solution of ses-
quichloride of uranium and chloride of barium in excess is treated with
excess of ammonia; the precipitate rapidly washed on a filter with
boiling water, before any carbonate of baryta becomes mixed with it ;
and lastly dried and ignited. (Arfvedsoa.) In this process, nranate
of ammonia is also precipitated, together with the uranate of baiyta.
(Berzelius.) — 2. By mixing nitrate (or acetate, Werikeim,) of uranic oxide
with excess of baryta-water, and exhausting the precipitate with water as
long as baryta is dissolved. (Berzelius.) — 3. By igniting tbe double
acetate of uranic oxide and baryta. (Wertheini.) — 4. By boiling nitrate
of uranic oxide with a large excess of baryta- water. (Kiihn, Ann, Fharm,
41, 337.) Uranate of baryta is yellowish-red, or, when reduced to
powder, orange-yellow. When it is heated to redness in hydrogen gas, it
forms water, and is converted into a mixture of uranous oxide and
baryta, spontaneously inflammable at ordinary temperatures. (Benelins.)
Calculation. Berzelius (2). Werthetm (2or3). Kttlm(4).
BaO 76-6 .... 21-01 .... 2M0 .... 21-43 .... 31'6
2U^(y 288-0 .... 78-99 .... 78-81 .... 77-89
BaO,2U«0» 364-6 .... lOO'OO .... lOO'OO ..„ 9932
Kiihn regards the compound (4) as BaO,U*0'; for thi«, however, the
quantity of baryta is insufficient.
Uranium and GALOitiif.
A. Uranatb of Limb.— -Uranic oxide precipitated by ammonia from
an acid solution coutaining lime, enters into combination with a portion
of the lime. (Bucholz.) — ^Many of the compact, dark yellow varieties of
uranium-ochre which, when ignited, remain yellow and yield water
but no oxygen gas, likewise contain lime and oxide of lead. (Berxelius.)
IT B. Carbon atb op Uranio Oxidb and Limb. — Vrano^alcie Car^
honate, — Found native as Lt^ngite. ( Vid. Medfidiie^ in/ra.)— This mineral
occurs in apparently amorphous, rounded masses, having a distinct cleav-
age-plane in one direction. It is transparent, has a beautiful apple-green
colour and vitreous fracture; hardness between 2 and 2*5. When gently
heated, it loses water and becomes greenish grey. Does not fuse at a
red heat, but turns black, and acquires an orange-red colour on cooling.
With borax it forms a yellowish glass in the outer, and a green glass in
URANIUM ANB CALCIUM. 191
the inner flame. Didsolyes in dilute hydrochloric acid, with violent
effervescence, forming a yellow solution which is precipitated yellow by
ammonia and carbonate of ammonia.
lAehigite. Smitb.
U«0» 144 .... 36-3 38-0
CaO 28 .... 71 8-0
2C0» 44 .... IM 10-2
20HO 180 .... 45-6 452
U«O»,CO2 + CaO,CO2 + 20Aq. 396 .... 100*0 1014
(J. L. Smith, Ann. Fharm. 66, 253.) T
C. Phosphatb of Uranic Oxidb and LiUB.'^Ufanchcalcie Phos-
phate. Found native in Calcareous UraU'tnica or Calcareous UraniU,
Crystalline system, the square prismatic. {Fig. 28, 24, 26, 28, 82, 33.)
Cleavage distinct, parallel to p ; less distinet, parallel to r, Sp. gr. =
d'l. Hardness equal to that of rock-salt. Lemon-yellow and transpa-
rent. When heated it gives off water and becomes itraw-colonred and
opaque. Before the blowpipe on charcoal it fuses, increasing slightly in
bulk, and forms a black mass having a semi-crystalline suiface. With
carbonate of soda it forms a yellow infusible slag ; with microoosmic salt,
it gives the usual reactions of uranium. It is soluble in nitric acid.
(Berzelius.)
At. Uran^nUea, from AvLton, Pdigot Berzelius. Werther.
BaO .... .... .... 1-51 .... 1-03
CaO 1 .... 280 6-10 .... 620 .... 566 .... 5-86
U'O* 2 .... 2880 62-69 ... 6301 .... 69-37 .... 63-28
cPO* 1 .... 71-4 15-54 .... 15-20 .... 14*63 .... 1400
HO 8 .... 720 15-67 ... 15-30 .... 1490 .... 1430
MgO&MnO .... .... .... .... 0-19
F,NH»& SnO^.... ..., .... .... trace
Matrix .... .... .... 2-70
{CaO,2U»0")cPO» + 8Aq. 4594 10000 .... 99-71 .... 9896 .... 98-47
IT D. Sulphate OF Uranic Oxide and Lime. — Urano-calcic Sulphate.
U*0',SO'+CaO,SO'4-15HO.— A mineral found in coniunction with
Liebigite, and accompanying an impure variety of pitchblende obtained
from the neighbourhood of Adrianople, appears to have this composition.
It is called Xfedjidite, — Transparent ; of dark copper-yellow colour and
imperfectly crystalline texture; fracture homy. Hardness about 2*5.
At a gentle neat it loses water and assumes a lemon-yellow colour;
blackens at a red heat. With borax in the blowpipe flame it behaves
like Liebigite, Insoluble in water^ but dissolves sparingly in dilute
hydrochloric acid. (Smith.) ^
XJ»0»
CaO
Medjidiie.
144
9ft
37-21
7-24
2S0*
80
20-67
15HO
135
34*88
U«08,S0»+Ca0,S0"+15Aq. 387 10000
192 URANIUM,
Uranium and Magnesium.
Uranatb of Magnesia. — Prepared by igniting the doable acetate of
uranio oxide and mai^esia. Yellowish brown. Its formula is MgO,
2UK)^ (Wertheim.) — The precipitate which ammonia produces in a mix-
ture of nitrate of uranic oxide and nitrate of magnesia^ contains magnesia
and ammonia besides uranic oxide. (Berzelius.)
Uranium and Silicium,
HydraUd Flwynde of SiUcium and Uranium, or Hydrofiuaie of
Silica and Uranotu Oxide, — Hydrofluosilicic acid gives with proto-
chloride of uranium a pale green gelatinous precipitate. If an excess
of h jdrofluosilicic acid is present, the solution retains a bluish green colour.
The precipitate, heated out of contact of air, yields water, hydrofluoric
acid, and sublimed silica. It is but slightly changed by boiling with
solution of potash. After drying it dissolves very sparingly in acids.
(Rammelsberg.)
Uranic oxide imparts to glass-finxes a yellow colour with a greenbh
cast.
Uranium and Tantalum.
Uranotantcdite appears to consist of TantdlaU of ITranons oxide, (0.
ftose, Pogff. 48, 555.)
Uranium and Tungsten.
A. Tungstate of Uranous Oxide, or Uranous Tungstate.—
Bitungstate of ammonia gives a brown precipitate with protochloride of
uranium. — The pale green solution still contains tnngstic acid, together
with a small quantity of uranic oxide. — Boiling potash removes the whole
of the tnngstic acid from the moist precipitate, but only a part after dry.
ing; ammonia separates a portion only, even from the moist precipitate;
carbonate of soda, in a state of fusion, decomposes it entirely. Nitric
acid dissolves the uranous oxide contained in the salt, converting it into
uranio oxide, and leaves insoluble yellow tnngstic acid, which however
retains a portion of the uranic oxide. The salt, when treated with
hydrochloric acid, turns blue and dissolves, forming a green solution,
mm which alkalis precipitate uranoso-uranio oxide. It is insoluble in
oil of vitriol. (Rammelsberg.)
Calculation. Rammelsberg.
2U0 136 .... 24-73 25*88
3WO» 360 .... 65-45 64-84
6H0 54 .... 9-82 9*25
2UO,3WO» + 6Aq 550 .... 100-00 99'97
B; Tungstate of Uranio Oxide, or Uranic Tungstate. — ^Light
yellow salt, insoluble in water, but soluble in the stronger acids and in
carbonate of ammonia. (Berzelius.)
URANrC VANADIATE. 193
Uranium and Molybdenum.
A. MoLYBDATE OF Uranous Oxide, or Uranous Molybdate. — Aa
excess of hydrochlorate of uranous oxide forms a greenish black precipi-
tate with monomoljbdate of ammonia. The supernatant liquid appears
dark blue, because a portion of the uranous oxide and a portion of the
moljbdic acid decompose each other, yielding uranic oxide which remains
dissolyed, and blue oxide of molybdenum. If an additional quantity
of ammonia be then added to the solution, a dark blue precipitate sepa-
rates, which is a mixture of blue oxide of molybdenum and molybdate
of nranic oxide. — The greenish black precipitate, freed by long-continued
washing with hot water from the blue oxide of molybdenum, leaves a
brownish powder, consisting of molybdate of uranous oxide mixed with
a small quantity of molybdate of uranic oxide. When ignited, it loses
9 '07 per cent, of water, and fuses to a yellowish green crystalline mass,
a portion of the molybdic acid being at the same time sublimed. It
likewise contains 39 '5 per cent, of uranous oxide. Boiling potash sepa-
rates the molybdic acid from the powder, and leaves dark-coloured
protoxide of uranium containing a portion of sesquioxide. Hydrochloric
acid dissolves the powder, forming a green solution, which becomes yellow
when diluted. — If protochloride of uranium is precipitated by an excess
of molybdate of ammonia, a scanty, brownish precipitate is formed, which
rapidly becomes dark green, and, on the application of heat, dissolves in
the dark green supernatant liquid. (Rammelsberg.)
B. Molybdate op Uranic Oxide, or Uranic Molybdate. — Molyb-
date of ammonia precipitates from sulphate of uranic oxide a pale sulphur-
yellow powder, which contains 56*25 per cent, of uranic oxide, and 43*75
of molybdic acid. The precipitate turns blue, either when brought in
contact with moist paper, or by long exposure to heat (Brandos) ; it is
insoluble in water, but dissolves in the stronger acids, and in carbonate
of ammonia. (Berzelius.)
C. Uranic Sulphomolybdatb. — A compound of tersnlphide of
molybdenum with sesquisulphide of uranium.— Formed when a salt of
uranic oxide is precipitated by sulphomolybdate of potassium. — The
precipitate is dark brown, and permanent in the air. (Berzelius.)
D. Uranic Persulphomolybdatb. — A compound of tetrasulphide
of molybdenum with sesquisulphide of uranium.— An aqueous solution of
persulphomolybdate of potassium added to the solution of a uranio salt,
throws down a dark red powder. (Berzelius.)
Uranium and Vanadium.
Vanadiateof Uranic Oxide, or Uranic Vanadiate. — Uranic salts
give lemon-yellow precipitates both with mono vanadiate and with bivana-
diate of potash. (Berzelius.)
vol. IV.
194 URANIUM.
Uranium and Chromium.
Proiochloride of uranium yields with monochromate of potash, a
yellowish hrown precipitate, which is soluble in excess of protochloride
6f uranium, and appears to be a mixture of chromate of uianio oxide,
ftnd ohromite of uranous oxide. (Rammelsberg.)
Chromate op Uranic Oxide, or Uranic Chromate.—^. More fietl^
iral salt? — Monochromate of potash gires an ochre-yelloHr precipitate
with nitrate of uranic oxide. (Moser.)
h. Acid chromate? — The yellow rongh-flavoured solution of uranic
earbonate in aaueous chromic acid yields small, bright red, cubic and
dendritic crystals. The salt fuses at a low red heat, undergoing partial
decomposition : on dissolving the dark brown mass in water, small por-
tions of chromic oxide and nranoso-uranic oxide remain behind. (John.)
Other Compounds op Uranium.
When hydrogen gas is passed orer the compounds of uranic oxide
with the oxides of lead, iron, Qopper, &c., heated to redness, residues
are obtained which take fire in the air at ordinary temperatures, and are
reconrerted into uranates of the metallic oxides. (Arfvedson.)-^The con-
clusion of Arfvedson that alloys of uranium with the above metals are
produced under these circumstances, is rendered doubtful by Peligot's
researches; probably they are mere mixtures of lead, iron, or copper,
with uranous oxide; since, according to Peligoti these compounds are
likewise pyrophoric.
Chapter XXIII.
MANGANESE,
Soheele. Opusc. 1, 227; also, Crell. N. Entd. 1, 112 k 140.
Hjelm. Crell Ann, 1787, 1, 158 k 446.
Bergman. Opusc. 2, 201.
John . N. Gehl 3, 452 ; 4, 436.
fierzelins. Oxides of Man^nese. Sehw. 7, 76. — Also, Ann, Chim,
Phy$. 5, 149; also, N, Tr. 2, 2, 359.
Berzelius & Arfvedson. Ann. Chim. Pkyg, 6, 204.
Arfvedson. Oxides of Manga^se. Schw, 42, 202.«— Sulphide of Man*
ganese, Pogg, 1, 50.
I
MANOAMBSS. 195
ChevreTil. Mineral Chameleon. Ann, Chm* Phy$. 4, 42; also^ Sehw,
20, 824; ako, K Tr. 2, 1, 188.
Cheyillot <fe Edwards. Mineral Chameleon. Ann, Chim. Phy». 4, 287;
8, 337 j also, N. Tr. 2, 1,199; 3, 2, 113; the former also in Schto.
20, 332.
Berthier. Oxides of Manganese. Ann, Chim. Phyi. 20, 187.
Forchhammer. Manganic and Permanganic Acids. Ann. Phil, 16, 130;
also, i^. Tr, 6, 1, 277. Oxides and Salts of Manganese. Ann. PhiL
17, 50.
Fromherz. Permanganic Acid. Schto, 41, 257; also, Pogff. 31, 677. —
— Salts of Manganese. iSchtu. 44, 327.
Tnmer. Oxides of Manganese. Edinb, J. of Sc. 4; also, Phil. Mag,
Ann. 4, 22 and 96; also, Kastn. Arch. 14, 359 and 424; further,
Schw. 56, 166; Fogg. 14, 211.
Brandos. Salts of Manganese. Pogg. 20, 55Q.
Mitscherlicfa. Manganic and Permanganic Acids. Pogg, 25, 287; alsoi
Schw. ^5, 62.
Bachmann. ZeiUchr, Phys. Hath, 4, 312; 6, 172; also, Schw, 55, 72;
Zeitichr, Phys. v. W. I, 262.
Schbnbein. Manganic and Permanganic Adds. J, pr, Chem, 41, 225.
Heintz. Manganons Salts. Pogg. 71, 449.
VSlker. Ann, Pharm. 59, 85.
Afangan, Braunstein-metal, Magnesium, Manganum, Manganese.
^tff^ory. — Black oxide of manganese, a substance long used to
decolorize glass, and called M<ignesia nigra from its resemblance to the
loadstone, was formerlj included among the ores of iron. It was, how-
ever, proved bj the researches of Pott, in 1740, of Kaim and Winterl, in
1770, and of Scheele and Bergmann, in 1774, that the metal contained
in this mineral is distinct from iron, and possesses characters peculiar to
itself. The metal itself was first eliminated by Gabn. — Chevillot 8t
Edwards, in 1818, pointed out that Mineral Chameleon, a substance
discovered some considerable time before, contained a peculiar acid of
manganese. — Forchhammer, in 1820, distinguished two acids of manga-
nese; and Mitscherlich, in 1832, fully confirmed the distinction.
Sources. This metal occurs in the several forms of manganoso-man-
fanic oxide; manganic oxide; hjdrated manganic oxide; peroxide;
jdrated peroxide; sulphide of manganese; carbonate of mansanous
oxide ; silicate of manganous oxide ; double silicate of alumina and man-
ganous oxide; a compound of manganic oxide and baryta; titanate of
manganous oxide ; a compound of manganic oxide and cupric oxide ; in
Helvin ; and in Earthy Cobalt. Also, in small quantities, often as colour-
ing matter, in a great number of siliceous minerals; in very small quantity
in plants ; and in still smaller quantity in animal substances.
Preparation, — 1. Either of the pure oxides of manganese is moistened
several times with oil, and heated to redness; then made into a thick
paste with a small quantity of oil; introduced into a charcoal crucible
(III., 467); covered with charcoal powder; and exposed to the strongest
heat of a powerful blast-furnace. (John.)*^2. An oxide of manganese
is mixed with a quantity of lamp-black, much leas than that which is
o2
1 96 MANGANESE.
required to reduce it, and the mixture made into a pasty mass with oil;
it IS then pressed into a charcoal crucible corered with charcoal powder;
and the bottom of a crucible fitted tight into the opening, and lut«d on
with clay; the whole is then heated in a blast-furnace for an hour.— ^
3. According to Pfaff, peroxide of manganese yields a metallic bead before
the oxy-hydrogen blow-pipe. The manganese obtained by the first and
second methods contains carbon (from O'l to 2*9 per cent., together with
1*9 per cent, of silicium, [from the charcoal,] Bachmann). On fusing it
with borax, the carbon is separated (according to John), and the metal
becomes more fusible; under these circumstances, howcTer, it may
combine with boron or sodium. The metal is preserved in an inyerted
vessel filled with mercury, or under rock-oil, or in a sealed glass tube.
Properties. — Greyish white, without much metallic lustre; very soft,
very brittle, and very easily split; has a fine granular texture; specific
gravity =6' 85, (Bergmann,) f'O (Hjelm), 8*013 (John). Fuses in the
strongest heat of a blast-furnace.
IT According to Berzelius, manganese, like silicium and many other
elements, is susceptible of two allotropic conditions. As obtained by
reduction with carbon in the blast-furnace, it has the well known pro-
perty of oxidizing at ordinary temperatures, either in the air or under
water, with evolution of hydrogen. Sefstrom, however, has observed
that, when manganese is reduced in contact with silica, (the resulting
compound containing about 6 or 7 per cent, of silicium), a regulus is
obtained, which does not differ |much in appearance from the ordinary
variety, though wanting all its usual characters : — for instance, it sustains
a red heat without oxidation, and resists the action of aqua-regia. The
presence of the silicium is not sufficient to account for this peculiarity,
inasmuch as platinum, when alloyed with a large quantity of silicium, is
readily dissolved by aquarregia. It must, therefore, arise from the
altered condition of the metal itself ; the silicium, in its transformation
into Si/3 (III., 352), probably induces the change of the manganese into
Mn/3, at a temperature at which this change would not take place with
manganese alone. This peculiar condition of manganese may explain
the peculiarities of the native red siliceous manganese, and of many other
silicates containing manganese, which are perfectly indifferent to acids,
even to nitric acid, which usually raises lower oxides to higher degrees- of
oxidation. ^
Atomic tmght = 27*6 Berzelius; 28 (Turner).
Compounds of Manganese,
Manganese and Oxygen.
Among the heavy metals, manganese, iron, and zinc, have the greatest
affinity for oxygen; and at ordinary temperatures, none of them are
oxidized so rapidly as manganese, either in the air or under water. It
is oxidized still more rapidly by all the aqueous acids, the action being
attended either with evolution of hydrogen gas having a peculiarly
offensive odour, or, as in the case of nitric acid, with decomposition of
the acid.
Manganese kept under water and out of contact of air, as long as it
disengages hydrogen gas, is converted into a green oxide, in which 1 00
MANGANOUS OXIDE. 197
parts of maDganese are combined with only 14 '9 parts of oxygen.
(John.) Similar results were obtained by Bachmann : — ^the manganese
was yery slowly disintegrated in cold water, but more rapidly in hot
water; hydrogen gas, haying a foetid odour, being eyolyedf, and a
greyish white oxide produced, which, when ignited out of contact of
air, became greenish grey, and pale green on cooling; in an earlier ex-
periment, 100 parts of metal had absorbed in this process 14*285 parts
of oxygen (=28:4); according to a later experiment, the amount of
oxygen was 19*5 (=28 : 5'46). Hence, the oxide formed by the action
of water appears to be a suboxide; according to Bachmann, howeyer,
it dissolyed in hydrochloric acid without disengagement of hydrogen
gas, and formed protochloride of manganese.
From these experiments, it might be concluded, that what has hitherto
been regarded as metallic manganese really contains oxygen; and hence,
in passing to the state of nianganous oxide, it takes up less oxygen than
is commonly supposed. The statements of John and Bachmann, howeyer,
require confirmation. According to Regnault {Ann. Chim. Phys. 62, 850),
finely diyided manganese, kept under water at ordinary temperatures,
slowly liberates hydrogen gas; but if heat be applied eyen much below
100^, the eyolution of gas becomes rapid, and the manganese is con-
yerted into a yellowish brown powder, which becomes dark brown on
exposure to the air.
The hydrogen gas, obtained by dissolying manganese in dilute sul-
phuric acid, deposits, when exploded with an excess of oxygen gas, a
white, greasy substance, which retains the disagreeable odour of the gas.
Manganese, gently heated in a current of oxygen gas, becomes red-hot
from the heat eyolved by its combustion. Carbonic oxide gas does not
appear to be decomposed by manganese at a red heat. (Bachmann.)
Manganese does not reduce any simple metallic salt, except the salts of
silyer and gold ; and with these the reduction is yery slight. (Fischer,
Fogg, 16, 128.)
A. Manoanous Oxide. MnO.
Protoxide of Manganese, Manganoxydul.
Formation, — By exposing manganese to the action of water, air
beinff excluded; by dissolying manganese in any aqueous acid; often also
by the action of an acid on the higher oxides of manganese.
Freparatian,^^!, By gently igniting carbonate of manganous oxide
(or the hydrated oxide : H. Davy) in a yessel from which the air is
excluded (Scheele); or by passing hydrogen gas oyer the salt during
ignition, to preyent any oxidation from without. (Arfyedson.) — 2. By
passing hydrogen oyer gently ignited manganoso-manganic oxide.
(Forchhammer, Turner; see also Fuchs, Sehw, 60, 345.) — 3. By exposing
manganoso-manganic oxide, manganic oxide, or peroxide of manganese,
for a long time to a moderate white heat in a charcoal crucible. (Berthier.)
—4. By igniting oxalate of manganous oxide out of contact of air. (Las-
saigne.) — 5. By mixing equal parts of fused chloride of manganese and
carbonate of soda with a small quantity of sal-ammoniac, heating the
mixture till it fuses, and exhausting the fused mass with water, when
cold. (Liebig Sc Wdhler, Fogg. 21, 584.) — 6. By igniting oxalate of
manganous oxide in a retort. (Bachmann.)«-Manganou8 oxide is pale
198 MANGANESE.
green (Forcfafaammer), pistachio-nat green (Arfyedson), tincal- green
(Tuiner), dark greyish green (Berzelias), greenish grey (Lipbig &
Wohler), sometimes pale greyish green, sometimes pale green (Gmelin)^
greenish black, (H. Davy); turns pale yellow when heated (Forchhammer).
Pulverulent after gentle ignition; cakes together when more strongly
heated. According to Despretz {Ann. Ckim. Phyi. 43, 322), it fuses
in the blast-fumacei and forms a mass haying a fine green colour.
Berzeliufl & Berg-
Calculatioii. Forchhammer. Arfvedson. H.Dayy. man.
1&» 28 .... 77-78 .... 7616 to 7678 .... 7807 .... 79 .... 80
O 8 .... 22-22 .... 23-84 „ 2322 .... 2193 .... 21 .... 20
IftnQ 36 .... 100*00 .... 10000 10000 .... 100*00 .... 100 .... 100
(MnO = 345-89 + 100 » 445-89. BerzeUos.)
Pecampositions. — When ignited alone, it does not part with oxygen
at any temperature; at a bright red heat, it is decomposed by charcoal,
but not by hydrogen or carbonic oxide gas. When ignited in a current
of sulphuretted hydrogen gas, it is resolved into water and 123*66 per
cent, of sulphide of manganese; and by ignition with sulphur, into sul-
phurous acid and oxysulphide of manganese. (Arfvedson.)
Oomhinaiions. — a. With Water. — Hydrated Manoanous Oxide. —
Prepared by decomposing a soluble salt of manganous oxide with potash.
— White flocculent precipitate. — According to Sir U. Dayy, it contains
24 per cent, of water. — When exposed to the air, it rapidly turns brown,
from formation of hydrated manganic oxide, or, according to Phillips,
of hydrated peroxide of manganese.
5. With Acids, forming the Salts of Manganous Oxide, or Man-
GANOUS Salts. The protoxide has a great affinity for acids, and its salts
are yery nearly neutral to test-paper. They are for the most part soluble in
water, and either pale rose-coloured or colourless.* Those which contain
a fixed acid, sustain a strong red heat without decomposition. With fluxes
they behave like the oxides of manganese. ( Vid. Manganese and Sodium,)
Those manganous salts which are insoluble in water, dissolve in hydro-
chloric acid. Those which are soluble in water have an astringent taste.
The protoxide of manganese contained in the solution of one of these
salts is not converted into a higher oxide by atmospheric air, nitric acid,
or chlorine. The hydrated peroxide is very slowly precipitated from
the eolations of these salts by chloride of lime, acconling to Phillips,
and yery slowly by hypochlorous acid, according to Balard ; likewise by
bromic acid, (Rammelsberg,) or bromate of potash on the addition of oil of
yitriol, or by chlorate of potash with oil of yitriol, on the application of
heat (the addition of a small quantity of chlorate produces only a reddish
colour in the solution). (Simon, Repert, 65, 208.) Manganese is not pre-
cipitated in the metallic state by other metals. Canstic potash and soda
* Y VSlker (Ann, Pkarm. 59, 27) hat shown that the raddiah tint obsenred in
loltttions of manganous salta, especially when in lai^ quantity, is owing to the presence
of a higher ozide^ and that the pore salts are perfectly colourless. In some cases, how-
ever, it is caused by a small quantity of cobalt, which usually accompanies manganese;
but this may be readily determined by adding sulphurous acid or some organic substance
to the solution, whereupon, if the colour proceeds from the presence of a higher oxide,
it instantly disappears.^
MANOANOUS SALTS. 199
aepavate tbe whole of tlie manganese in the form of white hjdrate of mani
ganoua oxide, which rapidly turns brown in the air. Ammonia, when
added even in large excess, precipitates from a neutral solution only
half of the manganous oxide, in the form of a white hydrate which turns
brown in the air; the remainder of the maneanous oxide unites with
the ammoniaoal salt produced, and forms a double salt not deoomposible
by ammonia out of contaet of air i
2(MiiO,SO») + NH» = (NH»,SO» + MnO,SO*) + MnO.
If then the solution contains a quantity of free acid, at least equal to that
which is in combination, or if it contains a corresponding quantity of an
ammoniacal salt, ammonia produces no precipitate; because the ammoniaoal
salt — either formed at the time or already present-r-combines with the salt
of manganese, forming a double salt which is not decomposed by ammonia.
From the same eause, the hydrated protoxide of manganese precipitated
by either of the alkalis, redissolyes in sulphate, hydroohlorate, or nitrate
of ammonia, with disengagement of free ammonia, Nevertheless such n
mixture of a double salt of manganous oxide and ammonia with excess of
ammonia gradually becomes turbid in the air; and, if the latter be present
in sufficient quantity, deposits the whole of the manganese in the form of
brown hydrated sesquioxide. In this case, the affinity of ammonia in
excess for the acid combined with the mangtfnoua oxide, and that of the
atmospheric oxygen for the manganous oxide, act together in producing
the result. Monocarbonate of ammonia, potash, or soda throws down
white carbonate of manganous oxide, which does not turn brown in the
air, and is sparingly soluble in a cold solution of sal-ammoniac. Bicarbo-
nate of potash precipitates a concentrated solution immediately, and
renders a dilute solution slightly turbid; but if the latter contains any
free acid, so that an excess of carbonic acid is set free, no precipitate is
formed. In this case, bicarbonate of manganous oxide is formed, which
can exist only in the presence of a large quantity of water; after long
exposure to the air, however, white monocarbonate of manganous oxide ia
precipitated and carbonic acid evolved. Carbonate of lime, even with the
aid of heat, gives no precipitate with manganous salts. (Fuchs, Schw. 62^
192.) The carbonates of baryta, strontia, Time, and magnesia do not pre-
cipitate these salts at ordinary temperatures, but completely on the
application of heat. (Demar^ay, Ann. Fhwnti. 11, 240.) Carbonate of
magnesia precipitates the manganese completely on boiling; calcined
magnesia still more quickly. (Dbbereiner, Schw. 63, 482.) Phosphate of
soda throws down white phosphate of manganous oxide which does not
undergo any alteration in the air (a precipitate is obtained even with a
solution containing one part In 500. Pfaj^. Hydrosulphuric acid gas or
water saturated with it does not affect those salts of manganous oxide
which contain one of the stronger acids, such as the sulphuric, hydro*
chloric, or acetic acid, even when the acid is not in excess : the most
that appears is a scanty white turbidity, arising from a trace of hydrated
sulphide of manganese, which disappears on the addition of a small
quantity of acid. (Wackenroder, N. Br. Arch. 16, 114.) But if am-
monia is added, or if the solution of the salt is mixed with an alkaline
hydrosulphate, the manganese is completely precipitated in the form of
fleah-coloured hydrated sulphide of manganese (or hydrosulphate of
manganous oxide), which is insoluble in excess of the alkaline hydrosul-
phate, but dissolves readily in concentrated acetic acid, and turns brownish-
black on exposure to the air. If a small quantity of iron be present, the
200 MANGANESE.
precipitate appears brown or black. Sulphite of potash (but not sulphite
of ammonia) added to a manganous salt, throws down sulphite of manga-
nous oxide on boiling. (Berthier.) Arseniate of soda throws down white
arseniate of manganous oxide. Oxalic acid precipitates from concen-
trated (not from dilute) solutions, after some time, a white crystalline
powder, consisting of manganous oxalate, soluble in hydrochloric or
sulphuric, but not in oxalic acid. Alkaline oxalates produce the same
precipitate eren in dilute solutions, not however in presence of sal-
ammoniac, nor with a large excess of the alkaline oxalate. Ferrocyanide
of potassium gires — ^in a solution containing 1 part of salt in 6000 parts of
water (Pfaff) — a white (or if copper is present, a reddish) precipitate
which is easily soluble in hydrochloric acid, unless, according to Otto
(Ann. Pharm, 42, 348), the solution contains an excess of the ferrocyanide,
or of sal-ammoniac and other salts. Ferricyanide of potassium gives a
brownish-yellow precipitate insoluble in hydrochloric acid.
The following re-agents produce no effect : chromate of potash, alka-
line succinates and benzoates, and tincture of galls.
B. Manganobo-hanoanic Oxidb. Mn'O^
Bed Oxide of Manganese,* Braum Oxide of Manganese, Deutoxffde de
Manganiee, Manganoxyd. — Found native as ffatiemannite.
Formation.'^l. Manganese exposed to (moist) air at ordinary tempe-
ratures, evolves hydrogen gas of a peculiar odour, and is converted into a
reddish brown powder. This must be regarded as a mixture of manga-
nese containing charcoal and silicium, with manganoso-manganic oxide;
since it dissolves in hydrochloric acid, with evolution of hydrogen gas,
and forms a brown solution, which, when heated, becomes colourless and
gives off chlorine. The oxidation takes place more rapidly, in proportion
as the manganese is more free from charcoal and the air is warmer and
contains more moisture. On dissolving the powder in hydrochloric or
nitro-hydrochloric acid, carbide of manganese [graphite 1] remains in
brilliant scales. (Bachmann.) If the metal is heated in the air, the con-
version into manganoso-manganic oxide takes place more rapidly, but
without incandescence ; in oxygen sas, the finely divided metal becomes
ignited. Carbonic acid is proaucecT at the same time from the charcoal
present in the manganese. (Bachmann.) — 2. The protoxide of manganese
obtained by gentle iraition — not the denser variety obtained by previous
exposure to a white heat, or prepared by the fourth method — turns brown
after exposure to the air for a few days, at ordinary temperatures. If it
be heated to a temperature below redness, or brought in contact at one
point only with a red-hot coal, it takes fire — as formerly observed
by Scheele — and is quickly converted into manganoso-manganic oxide,
exhibiting incandescence all the while; the denser variety of manganous
oxide, when heated to low redness, absorbs oxygen without incandescence.
According to Arfvedson, 100 parts of manganous oxide thus treated yield
from 107*04 to 107*35 parts of manganoso-manganic oxide. The prot-
oxide ignited in aqueous vapour is converted, with disengagement of
hydrogen gas, into manganoso-manganic oxide. (Regnault.) — 3. The
higher oxides, when strongly ignited, evolve oxygen, and are reduced to
the rod oxide.
MANGANOSO-MANGANIC OXIDE. 201
Preparation, — 1. Pare sulphate or faydrochlorate of manganous oxide
IB prepared from peroxide of mauganese (see these salts); carbonate of
manganoos oxide precipitated from it by the addition of an alkaline
carbonate; and the precipitate washed and dried in the air, and lastly
ignited. — 2. Pounded peroxide of manganese is freed from impurities,
such as carbonate of lime, by dilute hydrochloric acid; then mixed with
four times [this is too muchj its weight of oil of yitriol; the liquid evapo-
rated to dryness; the residue dissolved in water; and copper precipitated
from the fiitrate by hydrosulphuric acid : the excess of the latter is then
expelled from the filtered solution by boiling, and manganous carbonate
(containing iron) precipitated from the solution by the fuidition of carbo-
nate of potash. The washed precipitate is then treated with aqueous
oxalic acid in excess, which dissolves the iron; and the remaining manga-
nous oxalate is purified with water, and afterwards dried and ignited in
the air. (Lassaigne, Ann, Chim. Phys, 40, 329; also Schw, 5^, 160.)
Hatumannite occurs in acute square-based octohedrons. Figs, 21 and
22; « : e' = 105"^ 25'; e : ^' = 117*^ 54'; cleavage comparatively easy
parallel to p; less easy parallel to e, Sp. gr. =4*72. Hardness between
fluorspar and felspar. Brownish black, with semi-metallic lustre. Yields
a brown powder which dissolves in cold concentrated sulphuric acid,
forming a red solution. (Haidinger.) The artificial oxide appears some-
times as a reddish brown, sometimes as a cinnamon-coloured powder,
which turns black whenever it is heated.
Berzdiiu & Berg- Forch-
Calculation. Arfredson. ArfVedson. man. hammer.
3Mn 84 .... 72-41 7277 .... 72'74 .... 74 .... 70*4
40 32 .... 27-59 27*23 .... 27-26 .... 26 .... 296
Mn'O* 116 .... 10000 100-00 .... lOO'OO .... 100 .... 1000
Or : ArfVedson. Or :
MnO 36 .... 31-03 31068 2MnO 72 .... 6207
Mn»0» 80 .... 68-97 68932 MnO^ 44 .... 37*93
MnO,Mn«0». 116 .... 10000 100000 2MnO,MnOS 116 .... 10000
MnH)^ s 3 . 345*89 + 4 . 100 »= 1437*67. (BerzeUus.)
Turner found in Hausmannite: manganoso-manganic oxide, 98*098
per cent; excess of oi^gen, 0*217; baryta, 0*111; silica, 0*337; water,
0*435; besides traces of a metallic chloride. Rammelsberg found: prot-
oxide of manganese, 92*487; oxygen, 7*004; baryta, 0-150 (loss 0*359).
DecomposUians, — 1. Reduced to the metallic state by heating to
whiteness with charcoal. 100 parts of manganoso-manganic oxide heated
in a charcoal crucible yield 73*4 of metulic manganese. (Berthier.) —
2. Boiling concentrated nitric acid removes the protoxide from manganoso-
manganic oxide, first colouring it brown, and then converting it into black
peroxide. (Berthier.) 100 parts of manganoso-manganic oxide, when
boiled with dilute nitric acid, yield 47*93 parts of hydrated peroxide.
(Forchhammer.) — The peroxide obtained from 100 parts of manganoso-
manganic oxide yields on ignition, 35 parts (Berthier), 34*03 parts
(Forchhammer) of manganoso-manganic oxide; so that \ of the manganese
contained in the manganoso-manganic oxide is dissolved by the nitric acid
in the form of manganous oxide:
Mn^O^^ 2MnO + MttO^.
202
MANGANBSB*
116 parts of manganoso-maDganic oxide yield with boilmg dilute salpfanrio
acid (containing about 1 part of oil of vitriol to 11 parts of water) a
solution of manganous sulphate and 44 parts of peroxide of manganese.
i Turner.) — 3. Hydrochloric acid heated with maganoso-manganio oxide
brms protochloriae of manganese and gives off chlorine. Hot oil of vitriol
decomposes this oxide, forming sulphate of manganous oxide and libe-
rating oxygen gas. 100 parts of manganoso-manganic oxide fused with
bisulphate of potash evolve 7*5658 parts of oxygen. (Forchhammer.)
Comhinatums, — c^. With Water : — Htdbatb of Manoanoso-manoanic
Oxide. — Prepared by precipitating a salt of manganoso-manganic oxide
by solution of potash. Its colour is brown.
5. With Acids: — Forming the Manoanoso-manganic salts. — Manga-
noso-man^nic oxide dissolves only in hot and highly concentrated phos-
phoric oxide, or in cold concentrated sulphuric, hydrochloric, oxalic, or
tartaric acid, in small quantity and without neutralizing the acid. The
solution in phosphoric or sulphuric acid is bright red; the others
dark brown. Heat and the addition of water, or of deoxidising
agents, converts these salts (the phosphate excepted) into salts of man-
ganous oxide with large excess of acid. The manganoso-manganio salts
should perhaps be regarded merely as mixtures of manganous and man-
ganic salts ; manganic oxide, however, does not appear to be soluble in
acids by itself.
C. Manganic Oxide. Mn'O*.
Sesquioxide of Manganese, Black Oxide of Manganese, Triioxyde de
Manganise, Manganoxyd,
Found native in the form of Braunite, — Formation and Preparation.
— 1. By exposing peroxide of manganese or nitrate of manganous oxide
to a dull red heat for a considerable time. — 2. Probably also by prolonged
and very gentle ignition of metallic manganese, manganous oxide, or
manffanoso-manganic oxide, in open vessels. — 3. Probably also in some of
the decompositions of manganoso-manganic oxide by acids.
Braunite forms acute square-based octohedrons. Figs, 21, 24, and
other forms, e i c' = 109« 53'; e ; c* = 108° 39'. Cleavage parallel to
p, Sp. gr. =: 4*82. Hardness equal to that of felspar. Lustre semi-
metallic. Colour, brownish-black. Yields a powder of the same colour.
(Haidinger.) Artificially prepared manganic oxide is a black powder.
2Mii
30
Cakulation.
56 .... 70
24 .... 30
Benelins dc
Arfiredson.
.. 70-35 .
... 2965 .
Forch-
hAmmer.
. 70-4
. 29-6
Arf-
vedson.
70-76
29*24
John.
71-33
28-67
H.
Davy.
71-43
28-57
Mn'O* .... 80 .... 100 .... 10000 .... lOO'O .... 10000 .... 10000 .... 10000
MoO 36
MaO» 44
45
55
Or:
2MnO 72
8
BaO
SiO«
HO
90
10
Tnmer.
Braumte,
86-94
9-85
2*62
trace
0-95
MnO,MiiO«.... 80 .... 100 80 .... 100 .... 10036
MnSO> = 2 . 345-89 + 3 . 100 » 991*78. (BeneUas.)
MANGANIC OXIDE.
20S
jDeeompontions,^^!, When stroogly ignited, it disengages oxygen ga£i
and is converted into manganoso-manganic oxide. The loss of oxygen
amounts to 3 '05 per cent. (Forchhammer.) — 2. Decomposed by boiling
with nitric acid, into protoxide of manganese which dissolves, and peroxide
which remains undissolyed. (Berthier.) The same result is obtained
when manganic oxide is boiled with dilute sulphuric acid. (Turner.)^
8, Hot oil of vitriol reduces it to manganons oxide and dissolves it, with
evolution of oxygen gas; in hot hydrochlorie acid it dissolves with
evolution of chlorine.
ComMncaions, — a. With Water. — Hydrated Manoakic Oxide. —
Found native 9A Manganite or Afanganese-glance, — Obtained: 1. By ex-
posing the hydrated protoxide to the action of the air. — 2. According to
Berthier, by passing chloriue gas through water in which carbonate of
manganons oxide is diffused, the chlorine not being in excess. The
liquid is filtered, and the undecomposed carbonate removed by cold
dilute nitric or acetic acid. A portion of hydrated peroxide, however,
remains mixed with the hydrated sesquioxide.
The native compound forms large, steel-grey, rhombic prisms, belonging
to the right prismatic system. Fig. 61 and other forms, u : i£^=99° 40^;
cleavage parallel to u, u', m and t; less distinct parallel to p» — Specific
gravity 4-328; hardness equal to that of felspar. (Haidinger.) Yields a
reddish brown powder, which does not impart any colour, or only a slight
tinge of red, to cold concentrated sulphuric acid. The artificially pre-
pared hydrate is a bulky, dark brown powder, consisting of minute
scales; does not decrease in volume when heated in the water-bath; it
leaves a stain when rubbed. — Resolved by boiling with moderately con-
centrated sulphuric acid, into protoxide of manganese which dissolves,
and hydrated peroxide which remains undissolved. (Berthier.)
Tamer.
Ilefeld.
... 80-92
... 0'90
... 1010
2Mn
30...
HO
Calcnlation.
56 .... 62-92
24 .... 26-97
9 .... 1011
Or:
2MnO 72
8
HO 9
80-90
8-99
1011
Mii»OS,Aq.
89
100-00
Or:
2Mn»0* 232
O 8
3HO 27
86*89
300
1011
89
Arfvedflon.
Undenis.
86-41
3-51
10-08
.... 100-00
Berzelins &
AHVedson.
Undenis.
86-93
307
1000
10000
Turner.
Ilefeld.
86-85
3-05
10-10
3(Mii«0' + Aq.) 267 .... 10000 10000
100-00
100-00
6. By the intervention of other salifiable bases, manganic oxide may
be made to unite with certain acids, forming bright red, very solubfe
compounds — Manganic Salts — from which, according to Fuchs, car-
bonate of lime precipitates the manganic oxide.
Ores of manganese, containing more than 1| and less than 2 atom^
qf oxygen to 1 atom of manganese,
1. Compact and Fibrous Manganese ore, Psilomelaney ffartmangan,
Schwarzer Glaskopf, JSchwarzeisenstein, — Amorphous, dense, or stalactitic.
Specific gravity from 4*08 to 4*36; harder than apatite; fracture con-
choidal; black. — It is probably MnO;2MnO^; but the MnO is often
204
MANGANESE.
partly replaced by KO, BaO^ CaO, CuO, &c. Water also is often present,
and Bometimes the proportion of MnO' is greater; but tbe amorphous
state of the mineral renders it impossible to determine whether this
additional quantity of MnO' is an essential constituent, or merely an
accidental admixture. In Earthy cobalt and Cupreous manganese the
MnO is entirely replaced by CoO and CuO. (See these minerals.)
Many varieties of Psilomelane likewise contain carbonic acid, so tliat
when ignited| they erolTO that gas at first instead of oxygen.
Wacken-
roder. Fuchs.
a, b,
KO .... 4-5
NaO .... trace
BaO I'l
CaO
CuO
Mn»0* 84-9 .... 81-8
6-0 .... 9-5
Fe»C)» 4-5 ....
Si09 10 .... trace
HO 2-5 .... 4-2
Rammels-
berg.
r.
3*05
032
0*38
0-96
81-36
9*18
1*43
0*54
3*39
Tamer.
d.
16-365
69-795
7*364
0-260
6-216
e.
16-69
70*97
7-26
0*95
4*13
100*0
100*0
100-61
100*000 .... 10000
a is from Ilmenaa; h from Baireuth; before ignition it gives np
none of its potash to boiling water, but after ignition the whole ;— -c from
Horhausen; d from Schneeberg; e from Koman^che. If the sesqui-
oxide of iron and silica are regarded as adventitious, calculation gives
nearly the following formulie : a=MnO, 2MnO'; 6 = KO, SMnO,
20MnO' + 4Aq. = 1 Base : 5MnO« : lAq.; c = 6KO,lNaO,lCaO,
2CuO,20MnO,150MnO' + 30Aq. = 1 base : 5MnO» : lAq.; d and e
= BaO,2MnO,6MnO' + SAq. = 1 Base *. MnO' : 1 Aq. Hence a, then
( and c, and lastly d and e, form three different varieties.
2. Varvicite, — Texture crystalline-laminated; specific gravity from
4*531 to 4*628; resembles Manganite in appearance, and ryrolusite iu
hardness and in the colour of its powder.
4Mn
70...
HO...
Calculation.
112 .... 63*27
56 .... 31*64
9 .... 5*09
Phillips,
a.
63-0
31*6
5*4
177
.... 100*00
100-0
Tomer
9
Or:
b.
c.
4Mn'0«
464
• •••
87-38
86-89
• ••a
86-87
50
40
•••■
7-53
7*39
• •••
815
3H0
27
• •••
509
5-72
!•••
4-98
531
10000
10000
100-00
MnO, 3MnO'-|- Aq. — a and b are from Warwickshire, c from Ilefeld.
(R. Phillips and Turner, FkU. Mag, Ann, 5, 209 and 254; 6, 281;
7, 284.)
PEROXIDB OF MANGANESE.
205
D. Peroxide of Manganese. MnO^
Manganhyperoxyd, Peroaoyde de Manganese, — Found native as Pyr<y^
ItuUe, Grey Oxide of Manganese (Graubraunsteinerz) Soft Manganese
( Weichmangan or Braunstein).
Preparation, — Manganoso-manganio or manganic oxide is boiled
with strong nitric acid. — 2. Nitrate of manganous oxide is gradually
heated to incipient redness, and the residue pounded and freed by
boiling nitric acid from any remaining nuuiganous oxide; the insoluble
residue is then washed and yenr carefully heated to low redness, stirring
all the while. (Berthier.) — 3. Cfarbonate of manganous oxide is heated in
an open vessel to 260°, and any portions of carbonate which may then
remain undecomposed, are removed by cold and very dilute hydrochloric
acid; whereupon, according to Forchhammer, pure peroxide remains
behind. — 4. Carbonate of manganous oxide is carefully neated with fused
chlorate of potash, and the mass, when cold, well washed with water.
(Gobel, Sehio, 67, 177.)-*5. A solution of a manganous salt, even when
very dilute, provided it is perfectly free from iron, deposits peroxide of
manganese on the positive pole of a voltaic battery; a feeble current is
sufficient for the purpose. (Fischer, Kastn, Arch, 16, 219.)
Pyrolusite has the same crystalline form as manganite. It appears to
be formed from the latter by absorption of oxygen and loss of water ; for
many crystals are formed externally of pyrolusite, and internally of
manganite. (Haidinffer, Pogg, 11, 374.) Pyrolusite is somewhat softer
than manganite, and of specific gravity from 4*7 to 4*94; ithasa steel-
grey colour inclining to iron-black; its powder is grey. The artificially
prepared peroxide is black, with metallic lustre, hard, and tough.
(Berthier.)
Mn
20
CalculatioD.
... 28 .... 63-64
... 16 .... 36*36
Forchhammer.
63-65
36-35
....
BeneliuB &
Arffedson.
64 02
35-98
MnO«
... 44
116
16
....
....
....
100-00
87-88
12*12
100-00
Tamer
100-00
»
Or:
MnK)*
SiO«
HO
Elgenlrarg.
8606
11-78
0-53
0-51
1-12
Uefeld.
85-62
11-60
0-66
0-55
1-57
CaCl
trace
3MnO«
132
...«
100-00
10000
100*00
(MnO^ » 345-89 + 2 . 100 =: 545*89. Benelius.)
Pyrolusite frequently contains manganite, psilomelane, (and with it
also baryta, copper, &c.) sesquioxide of iron, alumina, quartz, and car-
bonate of lime ; also sulphate of lime and chloride of calcium ; whence,
according to R. Phillips (Phil. Mag. Ann, 1, 314), native peroxide of
manganese, unless previously washed with water, frequently evolves
chlorine when treated with oil of vitriol ; in other cases, however, the
chlorine arises from hydrochloric acid contained in the oil of vitriol.
206 MANGANESE.
(II., 181, 182.) [For the mode of aaoertaining the per-oentage of per-
oxide of manganese in the yarioas minerals which contain it, md. Leyol,
Ann. Pharm. 44, 355; also Fresenius and Will, Ann. Pharm. 49, 125.]
Decompo9iHon$. — 1 . When peroxide of manganese is even gently ignited,
ft portion of its oxjgen is expelled in the gaseons form, and sesquioxide
left behind; at a higher temperature, | at., or 12-12 per cent, (according
to Berthier, 11*8 to 12 per cent.,) is given off, leaving manganoso-man-
ganic oxide. — 2. When ignited in a charcoal crucible, it yields 82 per
cent, of protoxide. (Berthier.) — 3. By heating with sulphur it is resolved,
with disengagement of sulphurous acid gas, into a compound of manga-
nous oxide with sulphide of manganese. — 4. When Leated with oil of
Yitriol, it first evolves one-fourth of its oxygen, and is converted into
manganic sulphate {vid. Hess, Pogg. 52, 116); afterwards, when the
heat is increased, another fourth of the oxygen is given off, and man-
ganous sulphate formed. {Sch. 16.) Strong boilin? sulphuric acid dis-
solves it, converting it into manganous oxide and liberating oxygen gas.
^5. Hot hydrochloric acid dissolves it, with evolution of chlorine and
formation of protochloride of manganese or hydrochlorate of maneanous
oxide. (Sch. 64 and 73.) — 6. It is also dissolved by hydrated sulphurous
acid, with formation of hyposulphate (II., 174^ and sulphate of manganous
oxide (MnC -|- SO' = MnO, SO') ; and by nydratea nitrous acid, with
formation of nitrate of manganous oxide. Nitric oxide, according to
Kastner {Kastn, Arch. 26, 165) acts in a similar manner, provided water
is present. By the addition of organic substances, such as oxalic acid,
sugar, &c., the carbon of which combines with the second atom of
oxygen, the solution of peroxide of manganese in nitric and sulphuric
acids is greatly fiEicilitated. — 7. By igniting peroxide of man^nese with
hydrate of potash in a close vessel, manganate of potash and manganic
oxide are produced. (Forchhammer, Mitscherlich.)
Combinations. — a. With Water.— Hydratbd Peroxide op Man-
ganese.
a. One-fourth hydrated, 4MnO*, HO. — Hydrated manganic oxide, or
the hydrated peroxide y, is boiled in moderately concentrated nitric acid,
and afterwards washed and dried over a water-bath. — Brownish-black,
dense, tenacious masses, having an earthy fracture. (Berthier.)
4Mn03
HO
•aft«t»*i«
CalcnlAtion.
176 9513
9 4-87
4MnO^H0
185
10000
Or:
4Mii»0*
80
3HO
464
64
27
• •••
• •••
&3'6a
11-53
4-87
Berthier. Rammelsberg.
84-0 .... 841
11-5 .... 11-3
4-5 .... 4-6
555 .... 10000 1000 .... 1000
fi. TrihydrcUed. — 3MnO',HO. — Separates spontaneously after a
short time from a solution of manganons bromate, in the form of a black
powder, which gives off the whole of its water, even at a temperature of
%0{f. (Rammelflberg, Pogg. 55, 67.)
PEROXIDB Of MANGANESE. 807
Ctlcoktion. Or : RammeUberg.
SMnO* 132 .... 93'6« Mt^O* 116 .... 82-271 q,.,-
HO 9 .... 6-38 20 16 .... 11-35/ - ^^ '°
HO 9 .... 6-38 .... 6-24
3MnO9,H0 141 .... 100-00 141 .... 10000 .... 100*00
y. Dihydraied. — 2MnO^HO. — 1. Carbonate of manganous oxide is
diffused in water, and chlorine gas passed thron^h it uninterruptedly and
in large excess^ so that the liquid after 24 hours still contains free
chlorine; any manganous carbonate remaining in the precipitate is
remov^ed by cold dilute acetic or nitric acid, and the residue washed and
dried. — 2. A salt of manganous oxide is precipitated by chloride of soda
or chloride of lime, and the precipitate washed with water and dried.
(R. Phillips, Phil Mag. Ann. 5, 216; E. Dingier, Kastn. Arch, 18, 252;
vVinkelblech, Ann, Ffutrm, 13, 262.) According to Schaffner (Ann.
Pharm. 51, 168) this method yields the tribasio hydrate. — The black
hydrate, precipitated by Pelouze from salts of manganous oxide by
hypochlorous acid is probably the same compound. — IT 3. Schaffner
(Ann. Pharm. 51, 168} likewise obtained it by adding chloride of am-
monium and free ammonia to a solution of manganous sulphate, and
leaying the mixture exposed to the air. After some time, a leather-
brown precipitate is formed, which retains its colour on drying. IT — Dark
brown, loosely coherent powder, consisting of shining spangles; stains
the skin, &c.; does not conere into masses when heated in a water-bath.
(Berthier.) Reddish brown, very friable mass. (Winkelblech.) When
heated to dull redness, it gives off water and oxygen gas at the same
time. By boiling with moderately strong nitric acid, which dissolves a
small quantity of protoxide with evolution of oxygen gas, it is converted
into the compound m. (Berthier.) Does not dissolve completely in boiling
nitrie acid. Oxalic acid decomposes it rapidly, with great rise of
tempemture* (Winkelblech*)
CalcnUtion.
2Mn0« 68 90-72
HO 9 9-28
«fc
2Mn0^HO 97 10000
6r: Winkdbleeh. Berthier. Dingier.
2Mii»0* 232 .... 79-72 1 ^o-io i ^^ .... 17
40 32 .... 1100/ •"• ^^^ "" 111 .... 11
3HO 27 .... 9-28 .... 9-40 .... 12 .... 12
291 .... 100-00 .... 99-89 .... 100 .... 100
According to Berthier and Dingier, who dried the hydrate for ana-
lysis at 100^ the formnhi is not 2MnO',HO, but 3MnO',2HO.
^. Monohydrated. — MnO*, HO. — 1. Fonned by boiling hydrated man-
ganic oxide in dilute nitric acid. (Forch hammer.) — 2. By boiling manga-
nate or permanganate of potash with excess of sulphuric or nitric acid,
till the hydrate is precipitated. (Mitscherlich.) — As prepared by the
second method, it is brownish black; with an aqueous solution of sulphu-
rous acid, it yields nearly pure manganous hyposulphate, and only a smal
quantity of sulphate. (Mitscherlich.)
■
I
208 MAN6ANESS. .
Cakidatioii. Or: MittdieriicU.
MnO» 44 .... 83-02 MnH)* 116 .... 72*96 .... 72*57
HO 9 .... 16*98 20 16 .... 10-06 .... 9*88
3H0 27 .... 16-98 .... 17*55
MnO',HO.... 53 .... 100*00 159 .... 100-00 .... 10000
Ores of Manganese, principally containing hydraied Peroxide.
To this class belong most yarieties of Wad. The yarying admixture
of some of the lower oxides of mangauese (manganoso-manganic or man-
ganic oxide), as also of baryta, ferric oxide, &c. does not allow of any
stoichiometrical calculation of these imperfectly crystallized minerals. It
is sufficient^ therefore, to giye the results of some of the analyses.
Tomer. Berthier.
•
a.
>—
. b.
MnH)^
HO
BaO
.. 79-12
8-82
.. 10-66
1*40
• •••
• •••
■•••
■ »••
87*245
9-675
3-080
trace
MnO
O
HO .-
c.
62-4
12-8
15-8
• •••
• •••
• •••
68*9
11-7
12-4
7-0
••••
• •••
• •■•
• •■■
e.
46-5
71
8-8
Pe^O*
Clay
.... 6*0
30
3-6
Quartz .... .... 33-6
100*00 .... 100000 100*0 .... 1000 .... 99-6
a is Wad from Upton Pyne, consisting of loosely agglomerated brown
scales; specific grayity, 2-314. Similar to the aboye, in properties and
composition, is the Wad of Hiittenberg, in Carinthia, from Nassau and
from Elbingerode ; the oxygen in a is not sufficient to convert all the
manganoso-manganic oxide into peroxide. — 6 \ROchrey Wad; probably a
mixture of hydrated sesquioxide and anhydrous peroxide; if so, it does not
belong to this head. (Turner, N. Edinh. J. of Sc, 2, 213.)—^ occurs at
Grosyi, in brownish black, dull masses, which yield a reddish brown powder.
When ignited, it loses 24 per cent, of water and oxygen ; dissolyes slowly
in oil of yitriol, forming a yioletHsoloured solution ; eyolyes chlorine, eyen
with cold hydrochloric acid, and more readily than other yarieties of the
peroxide.— -li is Wad from Vicdessos, occurring in light, soft, warty
masses, which leaye a deep stain when rubbed. Before analysis, it was
freed from carbonate of lime by digestion in cold acetic acid ; by ignition,
it lost 1 9 per cent, of oxygen and water. — e, from Graubundten ; com-
pact, with dense granuhur fracture ; sometimes with metallic lustre, and
black; sometimes dull and brown. (Berthier^ Ann, Chim. Phy$, 51, 91.)
E. Manoantc Acid. MnO'.
Mangansaiire, Acide Manganique.
Formation,~^\, By igniting manganese or one of its oxides with a
fixed alkali in contact with air, or with chlorate of potash, or with a fixed
alkaline nitrate. — ^Peroxide of manganese, ignited with hydrate of potash,
even out of contact of air, yields manganate of potash, because a portion
of the peroxide is conyerted into sesquioxide.
Not known in the separate state.
\
PERMANGANIC ACID. 209
Calculation, according to Mitscherlich. ForcLliamiDer.
Mn 28 53*85 50*8
30 24 46-15 49-2
MnO" 52 10000 100-0
MnO' = 345*89 + 3 . 100 = 645*89. (BerzeUus.)
ComhincUions, — ^With Salifiable Bases^ forming salts called Manga-
NATES. The potasb, soda, baryta, and strontia-salts are nearly all that
are known ; they are obtained bj the method given for the preparation
of manganic acid. They are of a dark bluish screen colour. They deto-
nate on glowing coals. The first two are soluble in water, and form deep
green solutions. The solution is permanent when it contains an excess of
alkali ; but if the alkali is not in excess, the liquid turns red, and with
mater rapidity in proportion to the quantity of water present, and to the
facility with which the carbonic acid in the air has access to the alkali.
In this case, the alkaline manganate is resolved into permanganate-r- which
remains in solution and colours it red, together with free potash or car-
bonate of potash — and insoluble hydrated peroxide of manganese.
IT Schonbein regards the so-called salts of manganic acid as compounds
of peroxide of manganese and peroxide of the electro-positive metal : —
thus, manganate of baryta, according to his view, is MnO'-hBaO*, and is
resolyed by acids into a salt of baryta and a compound of peroxide of
"XKiaogauese and peroxide of hydrogen. H
SCKCMnC) = KO,MnW + MiiO« + 2KO.
By the addition of an acid, the decomposition and red colour are instantly
produced; with hydrochloric acid, the red colour soon passes into brown,
from formation of hydrochlorate of manganic oxide. Sulphurous and
hydrosulphuric acid decolorize the green solution by deoxidizing the
manganic acid.
F. Permanqanic Acm. Mn*0\
Hypermanganic acid, Uebermangansaure, Oxymangarudure, Acide
Oxymanganiqae.
Formation. — 1. By the decomposition of salts of manganic acid.
— 2. By bringing chlorine in contact with an oxide of manganese and a
fixed alkali in solution. Hence, in the preparation of chlorate of potash
with chlorine gas, if chloride ot manganese passes over into the aqueous
solution of carbonate of potash, the solution acquires a red tint. — 3. By
digesting a salt of manganous oxide with sulphuric acid and peroxide of
lead. (Forchhammer.)
This acid has not yet been isolated.
H According to Schonbein, that which has hitherto been regarded as
permanganic acid is really a compound of peroxide of manganese and
peroxide of hydrogen, or ozone, according to the formula 2MnO'-hdHO',
— inasmuch as, with deoxidizing agents, the so-called permanganic acid
behaves exactly like peroxide of hydrogen, or ozone itself. {Vid. Decom,"
position of hypermanganic add, infra.) (Schonbein.) IT
VOL, IT.
210
CaleulaHonf
According to Mltscherlich.
2Mn 56 50
70 56 50
MAKOANESB.
Forcbhammer.
431
56-9
Unvcrdorben.
... 58-74
.... 41-26
Fromherz.
59-45
40-55
MnW .... 112 100 1000 100-00
Mn'O^ = 2 . 345-89 + 7 . 100 = 139178. (Bcrzdins.)
. 10000
CamhinaUoM. — a. With Water. Aqjtbovb PsiiHAirGAiric Acid.*— «
Preparation. — 1 . From an aqueotu solation of permanganate of baiyta,
the baryta is precipitated by an eqnivalent quantity of snlphurio acid,
and the clear liqnid decanted. (Mitecherlich.)-— 2. Carbonic acid gas
is passed through manganate of baryta diffused in 30 parts of water,
stirring freqnently, till the ffreen colour of the powder iis changed into
brown. (This brown powder is a mixture of carbonate of baryta, hydrated
peroxide of manganese, and portions of undecomposed manganate of
baryta.) The decanted dark Tiolet solution, which, besides permanganic
acid, contains acid permanganate and acid carbonate of baryta, is boiled
for a quarter of an hour to expel carbonic acid and precipitate the carbo-*
nate of baryta; the small quantity of baryta still held in solution by the
permanganic acid is then removed by a few drops of dilute sulphuric acid;
the solution decanted, and boiled down to three-fourths of its bulk, and
lastly poured off from the precipitated hydrate of peroxide of manganese.
(Fromherz.) If the solution is eraporated in vacuo over oil of yitriol,
brown oxide of manganese is obtained ; but when evaporated at a gentle
heat, it yields, on cooling, small dark carmine-red needles containing
8-411 per cent, of water, which Fromherz regards as crystallized perman-
ganic acid. Mitscherlich and W&bler consider these crystals as acid per-
manganate of baryta, since pure permanganic acid is decomposed by boil-
ing its aqueous solution, aod cannot be obtained in the ciystalline state.
(Fogg. 25, 297; 31, 677; 32, 80.) On the other hand, the existence of »
crystallized acid permanganate of baryta is improbable ; and the neutral
salt would not be decomposed in vacuo. The subject deserves further
investigation. — 3. The green solution of mineral chameleon is precipi-
tated by nitrate of lead, and the precipitate, which consists of ses-
quioxide of manganese and peroxide of lead — after being washed but
not dried — ^is decomposed by long digestion with a mixture of one part of
oil of vitriol and ten parts of water, added in quantity not sufficient for
complete saturation. (Forcbhammer.) Under these circumstances, the
greater part of the manganic acid is decomposed, especially after the sul-
phuric acid has been completely saturated by the oxide of lead. (From-
herz.) — 4. Hiinefeld {Schw. 60, 133) decomposes manganate of baryta by
phosphoric acid. In this process, however, the presence of phosphoric
acid and baryta in the permanganic acid is scarcely to be avoided.
Properties. — Beautifully coloured liquid, which appears dark carmine-
red by reJQected, and dark violet by transmitted light ; when somewhat
dilute, it is reddish blue, and a still larger addition of water gives it a
carmine colour. The acid imparts a distinct red colour to very large
quantities of water. (Fromherz.) It is inodorous, and has at first a sweet,
and afterwards a bitter, rough taste (Fromherz) : its taste is pungent and
disagreeable. (Forcbhammer.) It stains the skin brown, but does not
redden litmus (Fromherz) ; destroys the colour of litmus and turmeric
paper, at the same time turning them brown, ^m deposition of hydrated
peroxide of manganese. (Forchammer, Mitscherlich.)
PERMANGANIC ACID. 211
Decampaskions,'^!, The aqneons fiolution deposits manganic oxide
when heated or exposed to light; it is partially decomposed at 45^, and
completely at 100 , — ^more rapidly also in proportion to the degree of
dilation ; a concentrated solution may be boiled for many honrs without
sensible decomposition. (Fromhere.) The solution is slowly decomposed
at about 20^, and rapidly between 30^ and 40°, yielding oxygen gas and
insoluble hydrated peroxide of manganese ; the decomposition is completed
by boiling. (Mitscherlich.) Forchhammer detected an electrical odour
[ozone?] when the solution was eraporated or exposed to the sun's rays.—
2. Many substances remove oxygen gas from aqueous permanganic acid at
ordinary temperatures, and throw down manganoso-manganic oxide for
hydrated peroxide of manganese ?]. Hydrogen gas passed through the solu-
tion decomposes it rapidly, with formation of water; recently ignited char-
coal, rapidly, without evolution of gas; phosphorus gradually, and phos-
phu retted hydrogen, immediately, with formation of phosphoric acid;
sulphur, in the course of a few days, with formation of sulphuric acid;
hydrosulphuric acid in excess, with separation of milk of sulphur, and
formation of water and sulphuric acid, which dissolves a portion of pro-
toxide of manganese (a small quantity of hydrosulpnric acid produces a
brown colour, and in a few minutes separates brown oxide of manganese^
after which the solution exhibits a pale rose colour); bisulphide of carbon,
with formation of sulphuric acid and probably also of carbonic acid [many
metallic sulphides are converted into sulphates by hypermanganic acidj;
iodine, at a moderate heat, with formation of iodic acid*. Zinc and iron
decompose the acid in the course of a few days; antimony, bismuth, lead,
copper, mercury, and silver, in about four weeks, being themselves con-
verted into oxides. Sesquioxide of chromium, teroxide of antimony, prot-
oxide of tin, protoxide of manganese, the yellow and red oxides of lead,
protoxide of iron, dioxide of copper and dioxide of mercury (generally, when
used in the hydrated state) these oxides themselves rising to a higher
degree of oxidation; arsenious acid, which is thereby converted into arsenic
acid, the solution, however, remaining brown ; ferrocyanide of potassium^
with formation of ferricyanide ; defiant gas, immediately, with formation
of carbonic acid, and probably also of water; alcohol and ether, appa-
rently with evolution of carbonic oxide gas ; sugar, gum, woody fibre,
paper, with formation of carbonic acid ; camphor, oil of turpentine (the
latter very quickly), turpentine, colophony, vegetable oil, without evo-
lution of gas, and probably, therefore, with formation of water; stearic
acid, oleic acid, morphia, urea, the colouring matter of blood, gelatine,
\ albumen, and fibrine ; likewise precipitate brown oxide of manganese from
\ permanganic acid. (Fromherz.) Sulphate of indigo, and the infusions of
galls, saffron, logwood, madder, columbo, rhubarb, quassia, aloes, and
Peruvian bark, are turned brown, and their colouring matter is destroyed.
(Fromherz.) — 3. Other substances, by a more powerful attraction for
* % The action of iodide of potassiam U peculiar : when aqueous hypennanganic
acid is poured into a solution of this salt, a large quantity of reddish brown peroxide ia
immediately thrown down, and the liquid assumes a brown colour, from separation of
iodine : if now the filtered solution be heated till the whole of the free iodine is expelled,
and very dilute sulphuric or phosphoric acid afterwards added, a fresh quantity of iodine
is precipitated — thus proving that iodate of potash and peroxide of potassium must be
contained in the liquid. TUs reaction is precisely similar to that of iodide of potassium
with peroxide of hydrogen or ozone. Caustic potash behaves nearly in a similar manner,
peroxide of manganese being precipitated and the filtrate containing peroxide of potas-
sium. (SchQnbein.) Finely divided platinum decomposes permaDganic acid rapWy. f
p2
212 MANGANESE.
oxygen, completely convert the permanganic acid into protoxide of man-
ganese, which then remains dissolved. Thus: sulphuroas and nitrous
acids — instantly, with formation of sulphate or nitrate of manganous
oxide; hydriodic acid — ^producing a reddish brown liquid, which contains
protiodide of manganese, together with free iodine (when a smaller quan-
tity of the hydriodic acid is used, brown oxide of manganese is precipitated,
and the brown solution contains free iodine); hydrochloric acid — with
formation of protochloride of manganese and evolution of chlorine ; chlo-
ride of sulphur — rapidly, with separation of sulphur and formation of
manganous sulphate ; oxalic, tartaric, and acetic acids — with formation of
a manganous salt. (Fromherz.) [According to Unverdorben, acetic acid
produces no effect ; according to the author's own experiments, it acts
very slowly .1 The following substances do not decompose permanganic
acid : — tin, chlorine, carbonic acid, boracic, phosphoric, sulphuric, nitric,
chromic, arsenic (Fromherz), or bromic acid. (Rammelsberg.)
h. With Salifiable Bases, forming salts called Permanganates or Oxy-
MANOANATE8. The potash and soda salts are formed by the spontaneous
decomposition of the corresponding alkaline manganates dissolved in
water. Most of the others are obtained by saturating aqueous permanganic
acid with such bases as have no tendency to combine with another atom
of oxygen; or, according to Mitscherlich, by rubbing together in a
mortar finely pounded permanganate of silver and a solution of the
hydrochlorate of the base, and decanting from the insoluble chloride of silver
produced. All filtration is to be avoided, on account of the deoxidizing
action of paper. The permanganates, in the anhydrous state, are dark
red or brownish black. They detonate with combustible bodies, like
the nitrates and chlorates, sometimes even by mere friction, the acid
being generally reduced to the state of protoxide of manganese. Sul-
phuric or phosphoric acid separates the permanganic acid from the base;
the acid, however, is soon resolved into oxygen gas and peroxide of
manganese, which is deposited at the bottom of the vessel. (Chevillot &
Edwards.) Hydrochloric acid gives off chlorine, and throws down ses-
quioxide or peroxide of manganese, which, on heating the mixture, is
again dissolved, as protochloride, with fresh evolution of chlorine. All
the permanganates are soluble in water, and many are likewise deli-
quescent; the least soluble is the permanganate of silver; hence, on
mixing the concentrated solution of another permanganate with nitrate of
silver, the permanganate of silver is precipitated almost completely, and
in the crystalline form. (Mitscherlich.) The aqueous solutions of the per-
manganates, like that of permanganic acid itself, have an intense red
colour, which is still perceptible even after considerable dilution. They
ore decomposed and decolorized by almost all substances which decom-
pose aqueous permanganic acid, tnose, namely, which are enumerated
under (2) and (3). (Fromherz.) — ^Ammonia decolorizes them immediately,
with evolution of nitrogen gas; organic colouring matters are more
slowly destroyed by them than bv the free acid. (Mitscherlich.) Sul-
phurous and phospnorous acids decolorize the permanganates rapidly,
forming salts of the protoxide. Hydrosulphuric acid precipitates a light-
coloured mixture of sulphur and hydrated sulphide of manganese; hydro-
sulphate of ammonia in excess throws down flesh-coloured hydrated
sulphide of manganese. (H. Rose.) — Permanganate of potash gives no
precipitate with the salts of baryta, magnesia, alumina, or with zinc,
cadmium or nickel salts, or with the salts of the higher salifiable oxides
of titanium, uranium, tin, iron, cobalt, copper, mercury, silver, gold,
CARBONATE OF MANGANESE. 213
and platinnm ; but with salts whose bases have a teDdency to absorb
oxygen, as with those of s^sqnioxide of chromium, (which is conyerted
into chromic acid)^ and of the protoxides of manganese, tin, lead, and
iron, and of dioxide of mercnrj, permanganate of potash forms preci-
Eitates, consisting of mixtures of sesquioxide of manganese and the
i^her oxide of the other metal. (Fromherz.) IT According to Schbn-
bem's yiew, the salts of permanganic acid are really compounds of perox-
ide of manganese and a quadoxide of the base : e. g, 2MnO' + KO.
In the case of potash, the existence of such an oxide^ corresponding to
the sulphur compound, does not appear yery improbable, inasmuch as
the action of ozone on potash appears to produce KO', and the ordi-
nary peroxide, KO', may really be nothing more than KO' + KO^
(Schdnbein.) IT
Manganese and Carbon.
A. Carbide of Manganese? — a. Manganese reduced by charcoal
always contains carbon, which, when the metal is dissolved, remains
behind in the form of a black powder.-— 5. Sulphocyanide of manga-
nese, when ignited, leaves a residue of MnC ; and cyanide of manganese,
a residue of MnC^, in the form of a fine, very combustible powder, or if
the heat is very carefully applied, in brilliant, colourless octohedrons.
PJ (Brown, J, jPr. Chem. 17, 492.) — c. Manganese-graphUe. — Produced
by the long continued fusion of manganese in a charcoal crucible;
according to Wollaston, also a large proportion of the graphite which
separates from purified cast iron, consists of carbide of manganese. It
has a stronger lustre than other kinds of graphite, is laminated, and may
be used for writing. (John.) [It probably consists of carbon, with man-
ganese accidentally adhering to it in small quantities.]
B. Carbonate of Manoanous Oxide, or Manoanous Carbonate.
— Found native as ifan^anese-^^r.— Crystalline system, the rhombo-
hedral. Occurs in obtuse rhombohedrons. Fig, 141, 143, 135; r^ : r^ or
r» {Fig. 141) = 73° S'; r^:7*= 106° 51'. Cleavage distinct parallel to
r'. Sp. gr. 3*55 to 3*59. Of the same hardness as felspar. Translucent;
of a rose-red colour and pearly lustre. Decrepitates when ignited,
becomes greenish grey, and afterwards turns black, if exposed to the
air, from formation of manganoso-manganic oxide: when ignited in a
close vessel, it leaves greenish grey protoxide. Ignited in a current of
chlorine gas, it gives off carbonic acid gas, and, according to Wohler,
is converted into a crystalline mixture of chloride of manganese and
manganoso-manganic oxide :
4(MnO, CO*) + CI = MnCl + Mn»0< + 4C0».
Dissolves very slowly in cold, and rapidly in warm hydrochloric
acid.
Stromoyttr*
/^
Calculation. KApnik. Nagyag. Freiberg.
MnO 36 .... 6207 CaO,CO».... 605 .... 10-58 .... 1S*08
C0» 22 .... 37-93 MgCCO^.... 3-31 .... 243 .... 726
MnO,CO« 89-92 .... 8664 .... 73*70
FeO,CO» .... .... .... 5-76
HO 0-44 .... 0'31 .... 00 5
MnO,CO».... 58 .... 10000 99'72 .... 9996 .... 9985
214 IfANOANESB.
Di-hydraied. — An aqueoas solation of salphaie of manganons oxide,
or protochloride of manganese, is precipitated with monooarbonate or
bicarbonate of potash or soda, and the precipitate washed with cold boiled
water, and dried in vaoao over oil of Titriol. If the precipitate is
washed with water containing air, and is likewise dried in the air, a
portion of the salt is converted into bydrated manganic oxide, which
gives it a red-brownish white tint. — Delicate, snow-white, tasteless powder,
permanent in the air. When heated to redness in an open vessel, it first
turns black and Uien brown, from formation of manganoso-manganio
oxide. By ignition with two parts of sulphur, it yields sulphurous acid
and carbonic acid gas, a small quantity of manganous sulphate, and a
large quantity of sulphide of manganese, mixed with a variable quantity
of manganous oxide, less, however, in proportion as the mixture has
been more gradually heated. (Arfvedson.) Chlorine- water expels the car-
bonic acid, and converts the carbonate into hydrated sesquioxide, which,
if treated with a larger quantity of chlorine, is converted into hydrated
peroxide of manganese. (Berthier.) When boiled with an aqueous solu-
tion of chloride of lime, it first forms manganoso-manganic oxide, and
then suddenly anhydrous peroxide of manganese, together with a small
quantity of permanganate of lime, which colours the solution purple-
red. (Bdttger, Beitrage, 2, 12.) — By a boiling solution of potash, which
removes the whole of the carbonic acid, it is converted into hydrated
protoxide of manganese. (Gmelin.) — When recently precipitated, it
dissolves in aqueous solutions of ammoniacal salts (Wittstein) ; but after
being precipitated for some time, it dissolves slowly, according to Witt-
stein, and not at all, according to Brett. — Soluble in 7680 parts of pure
water, and in 8840 parts of aqueous carbonic acid. (John.)
Calculation. Ure. Tomer. John. Forchhammer.
2MnO 72 .... 57*6 .... 57-3 .... 56*853 .... 55*84 .... 51*755
2C0» 44 .... 35*2 .... 354 .... 34*720 .... 34*16 .... 33*050
HO 9 .... 7*2 .... 7*3 .... 8-427 .... 10*00 .... 13*520
2(MbO,COS) + Aq. 125 .... 100*0 .... 100*0 .... 100000 .... 100*00 .... 98*325
The salt analysed by Ure was dried in the air at a temperature of
88° j that analyzed by Turner, in vacuo over oil of vitriol.
Manqanese and Boeon.
Borate of Manganous Oxide^ or Manganous Borate. — Borax
gives a white precipitate with manganous salts. The presence of a
magnesia-salt prevents the precipitation, and the precipitate formed in the
contrary case, is soluble in an aqueous solution of sulphate of magnesia.
(Berzehus.) Sexborate of potash does not affect the salts of manganous
oxide. (Laurent.)
Manganese and Phosphorus.
A. Phosphide of Manganese. — a. When manganese is ignited
with an equal weight of glacial phosphoric acid, (with or without ^ of
charcoal powder), or when phosphorus is thrown on ignited manganese, a
white brittle mass is obtained, having the metallic lustre and a granular
texture, more fusible than manganese itself; and permanent in the air« (Pel-
MAN0AN0U8 PHOSPHATE. 215
letier.)-^. Wben phoaphuretted hydrogen gas is passed over heated chlo-
ride of manganese, and the nndecomposed chloride afterwards dissolved
out with water, a black nietallio'Shining residue is left, consisting of phos-
phide of manganese. This compound does not exhibit a phosphorus-
flame before the blow-pipe; it is insoluble in hydrochloric acid. (H. Rose,
Fogg. 24, 335.)
B. Hypophosphitb op Manoanous Oxide, or Manoanous Hypo-
phosphite. — Formed when an aqueous solution of hypophosphite of lime
is boiled, for a long time, with excess of manganous oxalate. The
filtrate yields, on evaporation, an amorphous mass, which swells up when
heated, and evolves spontaneously inflammable phosphuretted hydrogen
gas. (H. Bose, Fogg. 12, 87.)
C. Phosphite of Manoanous Oxide, or Manoanous Phosphitb.
— Terchloride of phosphorus dissolved in water and neutralised with
ammonia, gives with hydrochlorate or sulphate of manganous oxide,
provided the manganous salt is not in excess, a reddish white precipitate,
which, after drying, resembles dried compact hydrate of alumina.
2MiiO
PC ..
2H0 .
Calculation.
H. Rose.
720 ..,.
49-52 ....
50*19
66-4 ....
38-10 ....
3802
18-0 ....
12-38 ....
.... 11-79
2MiiO,PO> + Aq 145-4 .... 100*00 10000
By drying at a rather elevated temperature, one atom of water is
expelled from the salt. (H. Rose.)
Manganous phosphate, when ignited in a retort, often becomes sud-
denly incandescent, this appearance bein^ the more quickly produced,
the more carefully the salt has been dried. Under these circumstances,
it gives off hydrogen gas charged with phosphorus, the quantity of which
is greater as the salt is drier; the gas, however, is not spontaneously
inflammable. A trace of phosphorus sublimes at the same time, and
the residue in the retort consists of manganous phosphate, with from 1 to
3 per cent, of blackish brown phosphoric oxiae. In the residual man-
ganous phosphate, more than 2 and less than 3 atoms of manganous
oxide are combined with one atom of phosphoric acid. If the salt has
been distilled after drying, the residue contains less phosphoric acid ; if
it be distilled in the moist state, it yields no sublimed phosphorus, and
the residue contains less phosphoric oxide and a larger proportion of
phosphoric acid. — 100 parts of the salt evaporated to dryness with nitric
acid, and ignited, leave 99*24 parts of ignited manganous phosphate,
2 atoms of oxygen replacing the 2 atoms of water. The salt is sparingly
soluble in water : it dissolves in an aqueous solution of hydrochlorate or
sulphate of manganous oxide. (H. Roise, Fogg. 9, 83, & 224.)
D. Phosphate of Manoanous Oxidb, or Manoanous Phosphatb.
»— When phosphate of soda is added to solution of manganous sulphate,
this salt is precipitated in the form of a white powder (which does not
appear crystalline under the microseope: HtitUst). Boiling solution of
potash removes the whole of the phosphoric acid. Water dissolves this
eompoond sparinfflyj solution of carbonate of ammonia, somewhat more
freefy; from the latter solution it is again deposited on boilinff. (Berze*
liuB.) It is partially soluble in hydrochlorate or nitrate of ammonia
216 MANGANESE.
(Brett); also in sulphate and succinate of ammonia, the liquid, how-
ever, showing a turhidity which is not removed even hj heat. The
solution in carbonate of ammonia is clear at first, but becomes turbid
after a while, the turbidity being increased by heating the liquid.
IT According to Heintz, this salt is composed of 3 atoms of manganous
oxide, 1 atom of phosphoric acid, and 7 atoms of water, 4 of which
are given off at 120% and the 3 others at a red heat. It is insoluble
in alcohol, but soluble in acetic acid, and, with greater feM^ility, in the
stronger mineral acids.
b. Diphosphate, — 2MnO,HO,PO' + 6Aq. — 1. Prepared by precipi-
tating a solution of manganous sulphate with a slight excess of phos-
phate of soda; dividing the solution, together with the precipitate, into
two equal parts ; adding enough nitric or hydrochloric acid to dissolve the
precipitate in one portion ; and then mixing the whole together. After
standing for a day or two, pale red or almost colourless crystals, having
a strong glassy lustre, are deposited. These crystals appear to be
tabular, right rhombic prisms, having the acute prismatic edges generally
replaced by planes, so that they look like hexagonal tables. The broad
terminal faces have a strong lustre, like that of apopyllite. By boiling
with w jber, the salt is resolved into a soluble acid salt and an insoluble
basic salt. (Bodeker, Ann. Pharm, 69, 206.) — 2. By adding ordinary
phosphate of soda to a solution of manganous sulphate acidulatea
with acetic (or with hydrochloric or phosphoric acid, in which case the
precipitation is slower), till the precipitate remains permanent. Care
must be taken not to throw down the whole of the manganese. The
precipitate, after a while, becomes crystalline and granular, the larger
crystals having a tinge of red. — 3. This salt likewise forms the residue
which is left on boiling an excess of the terbasic salt (vid, infra.) with
phosphoric acid, the supernatant liquid, which contains the acid salt,
being poured off, and the insoluble portion washed with water. When
thus prepared, it likewise becomes crystalline after a while. The crystals
dissolve readily in strong mineral acids, but with difficulty in acetic acid
and in water ; they are insoluble in alcohol. The salt loses 5 atoms of
water between 100^ and 120% another atom at 200° or above, and the
last at a red heat, so that its proper formula is probably, 2MnO,
HO + PO'-l-HO-l-SAq. (Heintz.)
Calculation. Bodeker. Hdnts.
2MnO 720 .... 34-73 34-86 .... 3458
P0» 71-4 .... 34-62 33-88 .... 34-61
7H0 630 .... 30-65 31-26 .... 3117
2MnO,HO,PO»+6Aq. 206-4 .... 10000 10000 .... 10036
c. Acid FhosphaU, — MnO,2HO,PO*H-2HO.— 1. Prepared by strongly
heating a mixture of manganic oxide and phosphoric acid. — 2. By-
dissolving the precipitate produced in the solution of a manganous salt
by ordinary phosphate of soda, in phosphoric acid, and setting aside to
crystallize. — Forms small prismatic crystals, which dissolve readily in
water, and are resolved by boiling alcohol into phosphoric acid, and a salt
containing 2 atoms of manganous oxide to 1 atom of acid. An aqueous
solution of the salt is also precipitated by alcohol with partial decompo*
sition. On charcoal, before the blow-pipe, it fuses readily in the outer
flame, giving off phosphoric acid and phosphorus in inflammable bubbles,
and yielding a black bead, which; when pressed out; appears transparent
PHOSPHATE OF MANGANIC OXIDE. 217
and yiolet-colonred ; in the inner flame, the bead, after a while, becomes
white and opaque, bat blackens again in the outer flame. It loses
2 atoms of water between 110® and 120°, the remainder at a red heat.
Calculation. Heintz.
MnO ' 28-0 .... 24-88 24-60
PO» 71-4 .... 49-92 49-17
4HO 360 .... 2520 2601
MiiO,2HO,PO» + 2Aq 135-4 .... 100-00 9978
£. Mangamous Pyrophosphate. — Formed by precipitating sulphate
of manganons oxide with pyrophosphate of soda. — Amorphous, white
powder, soluble in strong miueral acids, and in solution of pyrophosphate
of soda. — Decomposed by potash. By dissolving it in sulphurous acid-
water and boiling the solution, it is obtained in fine crystals, having a
mother-of-pearl lustre.
2MnO 72-0 .... 50-2 5015
PC* 71-4 .... 49-8 49-85
2MnO,PO» 143-4 .... 1000 10000
(Schwarzenberg, Ann. Fharm, 62, 2.) T
F. Mangai«ous Metaphosphate. — Precipitated, unchanged, from
a solution in nitric acid by hydrosulphate of ammonia, without formation
of sulphide of manganese, (Otto.)
IT Prepared by heating sulphate of manganous oxide with pure phos-
phoric acid to a temperature of 316^. — Insoluble in water and dilute
acids; soluble in concentrated sulphuric acid.
Calcnlation. Maddrell.
MnO 36-0 .,.. 33-321 33*22
P0» 71-4 .... 66-679 ........ 6678
MnO,PO« 107-4 .... 100000 ZZ 10000
(Maddrell, Aiem. Chem. See. 3, 273). T
G. Phosphate of Manqanio Oxide, or Manganic Phosphate. —
Manganoso-manganic oxide, or peroxide of manganese, heated nearly to
redness with concentrated phosphoric acid, yields a bright violet-coloured
mass, which is semifluid while hot and solid when cold. With water it
forms a columbine-red solution, which is not decomposed by the addition
of a large quantity of water, but is immediately decolorized by hydrosul-
phuric or sulphurous acid. After long standing, the solution deposits
light brown-red crystalline grains. — When manganoso-manganic oxide or
the peroxide is heated to full redness with excess of phosphoric acid, a
peach-blossom coloured mass insoluble in water remains, from which
solution of potash separates brown oxide of manganese, probably man-
ganic metaphosphate. (Gmelin.)
IT Hermann {Pogg. 74, 303.) finds that when manganic oxide
(obtained by igniting the nitrate of manganous oxide, resulting from the
mutual decomposition of manganous sulphate and nitrate of baryta), is
mixed with aqueous phosphoric acid, the mixture eyaporated to dryness,
and the residue heated nearly to redness, a yiolet-coloured mass is
obtained, which dissolves partially in water, forming a columbine-red
solution and leaying a peach-blossom coloured powder. The solution,
after long standing, deposits light brown crystalline grains (easily
218 MANOANBSE,
wftshed with water) mixed with a black sabetaQoe, probably eonsisting
of bydrated peroxide of manganeae. la oonseqaence of this admixture,
the crystalline grains did not yield constant results when analysed; they
appear, however, to contain ^om 35*12 to 37*35 per cent, of manganic
oxide, and from 48*99 to 49*91 of phosphoric acid. The peach-blossom
coloured powder is insoluble in all acids excepting the hydrochloric;
caustic potash, aided by heat, readily separates manganic oxide from it.
By strong ignition, it is reduoed to a yiolet glass, with loss (in a coyered
crucible) of 6*10 per cent.
noriuaiui*
Calculation.
MnW 80-0 .... 26-43
3PO» 2U-2 .... 68-78
2HO 180 .... 5-79
1.
2.
25*57
*.•«
25-37
68-25
».•»
69-01
6-21
••••
5-62
Mn«03,3PO*,2HO 312'2 .... 100*00 10003 .... 100*00 f
Manqanese and Sulphub.
A. Sulphide of Manganese. — Found natiye in the form of Man--
ganese-hlendey or Sckwarzerz. — 1. Formed by passing hydrosulphnrio acid
gas over heated manganous oxide or sulphate, (or carbonate, Pellenberg,)
as long as water continues to be formed. (Arf^edson.) — 2. By precipitat-
ing a manganous salt with hydrosulphate of ammonia, and heating the
washed and dried precipitate in a current of dry hydrosulphnrio acid gae,
as long as water and sulphur are given off. (Berzelius.)— 3. By igniting
peroxide of manganese or manganous carbonate with sulphur. The
sulphide of manganese thus prepared contains a small quantity of man-
ganous sulphate, and, moreover, an oxysulphide of manganese, the
quantity of which becomes greater the more rapidly the original mixture
is heated; by repeated ignition, however, with fresh quantities of sul-
phur, the oxide is almost entirely converted into sulphide of manganese.
(Arfvedson.) — 4. By heating manganous sulphate to whiteness, either
with ^ of its weight of charcoal, or in a charcoal crucible. (Dobereiner,
JSckw. 14, 208, Berthier.) In this process, also, oxysulphide of man-
fanese may be mixed with the pure sulphide. IT 5. Obtained in crystals
y passing the vapour of bisulphide of carbon over the native crystallized
hydrate of manganic oxide, ignited in a porcelain tube. The crystals of
sulphide of manganese thus obtained have the same form and nearly
the same lustre as those of the bydrated oxide. They are iron-black
with a tinge of green, and yield a dingy green powder. (Vdlker.) IT
Native sulphide of manganese crystallizes in iron-black cubes, with
cleavage parallel to the faces of a cube ; it is harder than felspar, of
specific gravity of 40, and yields a dark green powder. The artificial
sulphide prepared by the second and third methods, forms a dark green
powder; that prepared by the fourth, is a more bulky, fused, dark steel-
grey mass, having a semi-metallic lustre, crystalline-granular fracture,
and greyish green streak. (Ddbereiner, Berthier.)
Ddbereiiier. Arfredson. Del Rio.
Caloulation. Artificial, ArHflciaL N^gyag. Mexko.
Mn 28 .... 63*64 .... 65*86 .... 63*13 .... 62-29 .... 54-5
8 16 .... 36-36 .... 34*14 .... 36*87 .... .... 39*0
Vtuairts ...•••.• .... t... •••. .... .... D o
MnS 44 .... 100*00 .... 10000 .... 10000 .... .... 1000
OXYSULPHIDB OF MANGANESE. fiI9
The artifieial sulphide turns brown in the air, even at ordinary
temperatures; the native variety does not. Sulphide of manganesoi
when ignited in the air, is converted into sulphurous aoid and manga-
noso-manganic oxide, — the native sulphide, however, less easily than the
artificial variety. The ore from Nagyag yields 86*03 per cent, of
manganoso-manganic oxide. (Arfvedson.) — When fused with excess of
oxide of lead, it gives off sulphurous acid, and yields a slag consisting
of oxide of lead and protoxide of manganese, a portion of lead also
being reduced. (Berthier, Ann, Chim. Phys. 39, 252.) Detonates when
heated with nitre. It is but slightly decomposed by chlorine at high
temperatures, a small quantity of chloride of sulphur bein? formed. (H.
Rose, Pogg, 42, 540) j the sulphide prepared by the first method is resolved
into chloride of sulphur and rose-coloured, crystalline chloride of man-
ganese. (Fellenberg, Fogg, 50, 76.) When heated to redness in a current
of aqueous vapour, it gives off hydrogen and hydrosulphurio acid gas,
and is converted into manganoso-manganic oxide. (Regnault^ Ann^
Chim. Pkys. 62, 381.)
3MiiS + 4HO = Mn»0* + 3HS + H.
With aqueous acids, even with dilute nitric or nitro-hydrochlorie acid, it
gives off abundance of hydrosulphurio acid.
HydraUd Sulphide of Manganese, or ffydrosulphate qf Manganoui
Oxide, — Precipitated in flesh-coloured flakes on mixing a manganons salt
in solution with an alkaline hydrosulphate*. When the solution is largely
diluted, the precipitate appears white for the first few moments. Hydro-
sulphite of ammonia likewise produces a flesh-coloured precipitate.
(Wackenroder.) — The precipitate, when washed and dried in the air^
turns brown from oxidation. When heated to redness in a retort, it is
resolved into water and anhydrous green sulphide of manganese. (Ber-
xelius.) It precipitates sulphate of cadmium, acetate of lead, hydro-
chlorate of ferric oxide, nitrate of cobalt, nitrate of nickel, nitrate of
silver, and sulphate of copper. (Anthon, J, Pr, Chem, 10, 353.) The
metals contained in these salts are probably precipitated in the form of
sulphides, with formation of manganons sedts. Hydrosulphate of man-
ganons oxide turns white when boiled with potash ^Wackenroder) [the
alkali withdrawing the hydrosulphurio acid ; Omel%n'\, It dissolves in
sulphuric, hydrochloric, and dilute nitric acid, with evolution of hydro-
sulphuric acid gas; also in aqueous sulphurous acid (Berthier), with
separation of sulphur and formation of manffanous hyposulphite f.
(Rammelsberg.) [In this case no sulphuretted hydrogen is evolved, and
the solution contains manganons sulphate.] Hydrosulphate of manganons
oxide is slightly soluble m hydrosulphate of ammonia, but not when it
contains excess of sulphur. Hence, when a manganous salt is preci-
pitated by a large excess of hydrosulphate of ammonia, the filtrate, on being
exposed to the air, or mixed with hydrosulphite of ammonia, deposits a
further quantity of hydrated sulphide of manganese. (Wackenroder.)
B. OxTsuLPHiDB OF Manoanbsb MnS,MnO. Formed by passing
hydrogen gas over red-hot manganous sulphate. 100 parts of the anhy-
* f By passing a current of hydrosnlphuric acid gas through a solution of mangan-
ous acetate, a reddish precipitate is obtained, which contains from 2 to 2*5 per cent, of
water, f
t It is likewise soluble in acetic add — a property ;whieh is made use of in squffating
manganese from nicJ^el and cobalt, {Ann, Pkarm, 42, 347-)
Ar^edson.
Or:
Arfredson.
70*26
MnO
36 .... 45
.... 4«l
19-86
MnS
. 44 .... 55
.... 00
9-88
220 MANGANESE*
drons snlphaie yield water, salphorous acid, and 52*78 parts of oxysul-
phide of manganese. This compound is also formed, together with pure
sulphide of manganese, when an oxide of manganese is ignited with
sulphur. Pale green powder, of a lighter colour than sulphide of man-
ganese. (Arfredson.)
Calcnlation.
2Mii....M 56 .... 70
S 16 .... 20
8 .... 10
MnS^MnO .... 80 .... 100 .... 10000 80 .... 100 .... 100
At ordinary temperatures, it is permanent in the air; when heated,
it takes fire and hums, learing 96*27 per cent, of manganoso-manganic
oxide; a strong heat, howerer, is required to expel the whole of the
sulphur. Hydrosulphuric acid gas passed over it at a red heat, rapidly
decomposes it into water and 109*34 per cent, of sulphide of manganese.
Acids dissolve it with evolution of hyarosulphurio acid. (Arfvedson.)
C. Hyposulpbite of Manoakous Oxide, or Manganous Htpo-
SULPHITE. — ^When hyposulphite of baryta is precipitated by sulphate of
manfi;anou8 oxide, and the filtrate left to evaporate in the air, or under a
bell-iar over oil of vitriol, the salt is almost wholly resolved into free
sulphur and manganous sulphate. Alcohol added to the filtrate precipi-
tates a concentrated solution of the salt*— 2. Recently precipitated sul-
phide of manganese diffused in water, is rapidly converted by a current
of sulphurous acid gas into the same salt, with separation of sulphur.
(Rammelsberg, Pogg. 56, 305.)
D. Sulphite of Manganous Oxide, or Manganous Sulphite. —
Sulphurous acid eas is passed through water in which manganous carbo-
nate is diffused till the liquid emits a powerful odour of the acid ^John);
or the carbonate is dissolved In an excess of aqueous sulphurous acid, and
the liquid boiled till the non-acid salt is precipitated. (Berthier, y. Ann.
Chim. Phys, 7, 78.) White, crystalline-granular powder (amorphous
when prepared hj the second process : MuspraU\ tasteless, permanent in
the air, decomposible at a red heat, and insoluble in water, alcohol (John),
and ether. (Muspratt.) Very sparingly soluble in water (Heeren, Ber-
thier); readily soluble in aqueous sulphurous acid. (Berthier.)
MnO
SO>..
2HO
Calculatioii.
John.
Mnspratt
36 .... 41*86
... 40-2
.... 4203
32 .... 37-2n
18 .... 20-93
... 59-8
.... 36-47
.... 21-50
MnO,SO* + 2Aq 86 .... 10000 lOO'O .... 10000
E. Hyposulphatb of Manganous Oxide, or Manganous Hypo-
sulphate. — Formed by passing sulphurous acid ^ through water in
which finely divided peroxide of manganese is diffused. Berzelius first
purifies the powdered manganese, by boilin? it in nitric acid and washing
from all traces of hydrated sesquioxide, which would yield manganous
sulphate. (Vid. XL, 174; Formation of Hypotidphuric Add,) The
manganous sulphate produced at the same time, is removed either by
evaporation and crystallization; or by carefully adding baryta-water
MANGANOUS SULPHATE. 221
till the solntion no longer gires a precipitate with chloride of barium:
pare manganous hyposnlphate then remains in the liqnid in the form of
a deliquescent salt. (Welter & Gay-Lnssac.)
F. Sulphate op Manoanous Oxide, or Manganous Sulphate.—
Oil of vitriol dissolves the metal very slowly; dilute sulphuric acid, on the
eontnuy, with great facility. By heating peroxide of manganese with
oil of vitriol, oxygen gas is disengaged and the same compound produced.
Preparation. — 1. Peroxide of manganese— -previously freed from car-
bonate of lime and magnesia by boiling with dilute sulphuric acid — is
heated with an equal weight of oil of vitriol, and the resulting mass
gently ignited for an hour (by which means the sulphates of iron and
copper formed at first are decomposed); the manganous sulphate which
remains unaltered is dissolved in water, and the solution evaporated to the
crystallizing point. If the solution is still found to contain any oxide of
iron or copper, the former is removed by digesting the liquid with man-
ganous carbonate, and the latter subsequently by nydrosulphuric acid.—
2. Fischer ignites 1 part of peroxide of manganese with 4 parts of green
vitriol (Klauer, 5 parts of the peroxide with 2 parts of dehydrated green
vitriol),^ and then proceeds as above.
By igniting the crystals, the anhydrous salt is obtained as a white
friable mass having a bitter metallic taste, and reddening litmus very
feebly when dissolved. The salt sustains a continuous red heat without
decomposition; when strongly ignited, it gives off oxygen gas, sulphurous
acid, and anhydrous sulphunc acid, leaving mangauoso-manganic oxide.
When ignited with charcoal, it evolves sulphurous acid, together with
three or four times the quantity of carbonic acid and carbonic oxide gases,
and leaves a compound of protoxide and sulphide of manganese. (Gay-
Lussac.)
Anhydrous, Turner. Brandes. Forchbammer.
MnO 36 .... 47-37 47-33 .... 47*7 .... 45-62
SO» 40 .... 52-63 52-67 .... 523 .... 54-38
MnO,SO» 76 .... 10000 100-00 .... 1000 .... 10000
ComhinatWM with water, — The ignited salt absorbs water with great
avidity, and unites with it, forming a hard mass; when exposed to the air,
it takes up 3 atoms of water. (Brandes.)
a, Manokydrated,-^! , Obtained by drying the pentahydrated salt in
the air at a temperature between 194^ and 210^. (Graham, Phil, Mag, J.,
6, 420.) — 2. Precipitated in the form of a pale reddish-yellow powder, by
rapidly boiling an acid solution. (Kiihn &c Ohlmann, Schw, 61, 239.)
From a neutral solution, this compound is also precipitated on boiling.
(Graham.)
Calculation. Graham. Kiihii & Ohlmann.
MnO 36 .... 42-35) a^ .q / 41-23
SO* 40 .... 47-061 ^^^^ I 47-26
HO 9 .... 10-59 10-51 11-51
MnO»SO>+Aq. 85 .... 100*00 TTZ 10000 ZZ 10000
p. Bihydrated, — Separates on melting the heptahydrated salt alone,
or on boiling it with alcohol. (Brandes.) When the pentahydrated salt
is dried at 115° in the air, a compound is left containing 76 parts (1 atom)
of anhydrous salt to 9 92 parts (rather more than 1 atom) of water; if
S33 MANGANBSB.
it be dried fti ordinaiT temperatures in racuo orer oil of ritriol, 15*87
parts (almost 2 atoms) of water remain with 76 parts of the anhydrous
salt. (Graham.)
Calculation. firandes. Graham.
MnO 36 .... 38*30 1 ati-a 7Q«19
SO» 40 .... 42-55 ; ^ ^ ^^ ^^
2H0 18 .... 1915 191 20-88
MnO,SOS + 2Aq. 94 .... 10000 1000 10000
y. Terhydraied. — 1. Deposited in the form of a crystalline crust from
a solution of manganous sulphate not quite heated to the boiling point
(Graham); it frequently crystallizes also with the tetrahydfated saJt in
opaque white masses. (Brandes.) — 2. Produced from the tetrahydrated
salt by evaporation in vacuo over oil of vitriol. (Brandes.) — 8. Formed
when the anhydrous salt is exposed to the air till it no longer absorbs
water. (Brandes.)
Brandes.
Calculation. 1. 2.
MnO 36 .... 34-95 i 84-75 \ »,..-„
SO* 40 .... 38-84 38-71 J '
3HO 27 .... 26-21 2610 24-38
MnO,SO» + 3Aq. 103 .... lOO'OO 9956 100-00
h Tetrahydrated, — Crystallizes on evaporating an aqueous solution of
the salt in the air at a gentle heat, and indeed, aooording to Regnault, at
temperatures between 20^ and 30°. Large, transparent, right-rhombic,
and six-sided prisms^ of specific gravity 2*092^ according to Kopp; the
crystals, though of invariable composition, are sometimes pale rose-coloured,
and sometimes colourless. The rose-coloured crystals yield a rose-
colonred solution in water; the colourless crystals, a colourless solution.
(Fromherz, Brandes.) Wbhler observed well-defined, rose-coloured and
colourless crystals separate from the same solution.
Fromherz and Brandes attribute these differences of colour to the
presence of a higher oxide of manganese in the red salt. If rose-oohmred
sulphate of manganous oxide be precipitated from a not very dilute
solution by carbonate of potash; the washed carbonate of manganous
oxide redissolved in sulphuric acid, and precipitated by carbonate of
potash; again dissolved as before; and the same process repeated several
times ; a colourless solution is at length obtained, which yields colourless
crystals. For, on each solution in sulphuric acid, a portion of the higher
oxide present is resolved into oxygen gas and manganous oxide, till at
last it disappears altogether. (Fromherz.) [On the other hand, the
manganous carbonate is slightly oxidized by washing in the air; and if
the above explanation were correct, the rea salt would be decolorized by
boiling with sulphuric acid, or by a current of hydrosulphuric or sul-
phurous acid, which is not the case.] According to Brandes, the red salt
may be converted into the colourless salt by igniting, and then dissolving
it in water — or by boiling it in the state of powder with alcohol or ether,
and then dissolving in water — or by boiling its solution with a small
quantity of sugar; the colourless solution, obtained by either of these
methods, yields colourless crystals. [The salt obtained by igniting peroxide
of manganese, either with fuming sulphuric acid or with English oil of
vitriol, was always found by the autbor to yield red crystals after purifica-
MANGAN0U9 SULPHATE. 223
Hon, Thefle orysials when ignited and i^ssolved^ again gave a red solution.
The solution was not decolorized hj sulphurous acid or hj boiling for
two hours with sugar^ not even on the addition of eulphurio acid.] Brandes
obtained red crystals most frequently by dissolyiug peroxide of manganese
in sulphuric acid, after having ignited it with charcoal and oil; and
colourless crystals, by simply igniting the peroxide with oil of vitriol.
According to Brandenburg (Sckvf. 14, 836), the red salt is obtained by
igniting peroxide of manganese with fuming sulphuric aoid^ and white
crystals by ieniting it with common oil of vitriol. Berselius {Jahr&herM
\\y 186) attributes the difference of colour to isomerism.
Mitscherlich. Brandes. John.
Calculaticfn. Bed* Coltntrhu,
MnO 36 .... 3214) -« j31-61 .... 3114 .... 8100
SC 40 .... 35-72J • • '*° • 134-61 .... 3414 .... 3366
4H0 36 .... 3214 .... 32 .... 33*78 .... 3253 .... 3534
MiiO,SO>-f*4Aq. 112 .... 100*00 .... 100 .... 100*00 .... 97*81 .... 10000
In vacuo over oil of vitriol, this salt gives up 1 atom of water. When
heated, it decrepitates slightly and crumbles to a white powder without
fasing. When boiled in the state of powder with absolute alcohol, it
gives op 1 atom of water; but to cold alcohol or boiling ether it yields
nothing. (Brandes, Fogg. 20, 556,)
f. Fentahydrated, — 1. Crystallizes from a solution of the salt evapo-
rated in the air at temperatures between 7^ and 20°. (Regnault, Ann.
Chim, Fhys. 76, 200.) — 2. Produced by mixing the heptabydrated salt
with cold absolute alcohol. (Brandes.) The crystals have the form of
blue vitriol. (Mitscherlich, Regnault.)
Calculation. Mitscherlich. Brandes. Graham.
MnO,S03 76 .... 62-8 6154 .... 62 .... 6248
5UO 45 .... 37-2 3846 .... 38 .... 37*52
MnO^SOS-fdAq 121 .... 100*0 100*00 .... 100 .... 100*00
f. ffeptahydraied* — Separates from a cold saturated solution exposed
to the air at temperatures between — 4° and -f 6^. (Brandes, Regnault.)
Transparent, very pale red crystals (Brandes) having the form of green
vitriol. (Regnault.) It is moist to tne touch, and deliquesces between
the fingers; melts at a temperature but little above 19"^, with separation
of the bihydrated salt. By exposure to the air, between 9"^ and 11^, it
loses 4*9 per cent, of water; and between 12*5° and 15°, 18*6 per cent.
(3 atoms), efflorescing at the same time to an opaque mass. To cold
absolute alcohol it yields 2 atoms of water; to alcohol of 25° B., 3 atoms,
first becoming soft, then hard, and lastly crumbling to a crystalline
powder. To boiling absolute alcohol it fives up 4 atoms of water.
Boiling alcohol of 55 per cent, leaves the bihydrated salt, which, if
allowed to cool in the liquid, recombines for the most part with the water
separated. Cold ether does not remove water from the salt. (Brandes.)
Calculation. Brandes. John.
MnO 36 .... 25-90 26-75> ..
SO» 40 .... 28-77 28-34/ ••• ^*
7H0 63 .... 45-33 4500 .... 45
MnO,SOs + 7Aq 139 .... 100*00 10009 .... 100
224 MANGANESE.
n. Aqueatis solution. — 1 part of anhydrous salphaie of maneanoaa
oxide dissolyes in 1*78 parts of water at 6-25°, forming a syrupy liquid.
1 part of the tetrafaydrated salt dissolves at 6*25^ in 0*883 parts; at 10''
in 0-79 parts; at 1875° in 0-82 parts; at 37-5° in 0*67 parts; at 75° in
0*69 paHs; and at 101 "" in 1*079 parts of water; whence it appears that
the solubility of the salt increases up to 75"*, and decreases above that
temperature. A cold saturated solution boils at 102*1° and at the same
time becomes turbid^ from separation of a crystalline crust, which again
disappears as the liquid cools. (Brandes.)
Manganous sulphate dissolves in 500 parts of alcohol of 55 per cent.,
but is insoluble in absolute alcohol. (Brandes, Pog^. 20, 556.)
G. Manoanobo-manoanic Sulphate. — Manganoso-manganic oxide
(not the native hydrated sesquioxide) dissolves almost entirely in cold
pure oil of vitriol or in sulphuric acid diluted with 1 or 2 parts of
water, forming a fine red solution, which when diluted with water
becomes carmine-red; or 1 part of peroxide or sesquioxide of manganese
may be gently heated with 13 parts of oil of vitriol, till one-half the
quantity of oxygen capable of being driven off is expelled, and the
resulting mass dissolved in a small quantity of cold water; 1 part of the
salt imparts a bright red colour to 1280 parts of water. (R. Phillips,
FhU. Mag. Ann. 5, 214.) The liquid when heated deposits hydrated
peroxide of manganese, and is converted, without disengagement of
oxygen, into a colourless solution of manganous sulphate with excess of
acid. With pure alkalies and alkaline carbonates, it gives a reddish
brown, and with ferrocyanide of potassium a yellowish-brown precipitate.
On diluting with water, brownish-black peroxido of manganese is thrown
down after a while, leaving the protoxide in solution. Many deoxidizing
agents convert this salt into acid sulphate of manganous oxide. The
following substances decolorize the solution: sulphurous acid; nitric acid
containing nitrous acid; protochloride of tin; sulphate of ferrous oxide;
nitrate of mercurous oxide, with separation of white sulphate of mercuric
oxide; acetic acid; alcohol; rock-oil; naphtha; oil of turpentine; oil of
lavender; and starch;— oxalic acid turns the solution brown before deco-
lorizing it; arsenious acid acts in the same manner, but likewise
precipitates a brown oxide; hydrochloric and hydrosulphuric acids turn
the solution brown; tartaric acid and gum render it brown and turbid.
(Fromherz.) The solution may be regarded either as containing a
mixture of the sulphates of mtinganous and manganic oxides— or, with
Fromherz, as a mixture of sulphate of manganous oxide and sulphate of
manganic acid. According to the latter, a similar red solution may be
obtained by adding manganic acid to acid sulphate of manganous oxide.
If, however, the excess of sulphuric acid is insufficient, or if too large a
quantity of manganic acid is added, a brown precipitate is formed.
H. StUphate of Permanganic Acid ^— 'If to a solution of perman-
ganate of potash, water [sulphuric acid?] is added in such quantity as to
produce considerable rise of temperature, a violet vapour is disengaged^
which condenses on the sides of the vessel and rapidly undergoes decom-
position. (Chevillot & Edwards.) A mixture of powdered mineral
chameleon (manganate of potash) or of permanganate of potash with a
small Quantity of oil of vitriol (when an excess of the latter is used, the
result IS attended with a kind of explosion) gently heated in a retort,
evolves beautiful red vapours, which are very prejudicial to the lungs,
nTPO-SULPHOPHOSPHATB OF MANGANESE. 225
and in tbe absence of water, are very easily resolved into oxygen gas and
hydrated peroxide of manganese; but wben water is present in the
receiver, they are absorbed, forming a red solution. (Unverdorben, I^, Tr.
9, I, 80 j also Pogff. 7, 322.) Mineral chameleon when mixed with oil of
vitriol becomes heated to 130°, and evolves violet vaponrs, which have a
peculiar powerful smell, and condense in a receiver surrounded by a
freezing mixture, forming a red liquid which contains manganic and
sulphuric acids. Manganic acid heated with nearly anhydrous sulphuric
acid — ^gently at first, till a fused violet mixture is obtained, and then at
a higher temperature, whereby the mixture becomes green— yields
carmine-red vapours, which condense into dark carmine-red, needle-shaped
crystals; these crystals are decomposed by water into sulphuric acid and
aesquioxide of manganese [peroxide]. iCed vapours are also obtained on
heating manganate of baryta with nearly anhydrous sulphuric acid; but
when the fumes evolved from fuming oil of vitriol by heat are made to
pass over manganic acid, manganate of potash, or manganate of baryta^
no red vapours are evolved. (Uiinefeld, Schw. 60| 133.) Mineral chame-
leon prepared from materials perfectly free from chlorine likewise yields
the red vaponrs. (Gmelin.)
I. Sulphide of Carbon and Manoanesb.— Protochloride of man-
ffanese yields, at first, with hydrosulphocarbonate of lime a transparent
dark brown liquid, which afterwards turns yellow and deposits a reddish-
yellow powder. The powder becomes darker when dried, and is resolved
oy distillation into carbonic acid, sulphur, and a residue of green sulphide
of manganese; it dissolves sparingly in water, forming a yellow solution.
(Bersebus.)
K. Htpo-sulphopbosphatb of Manoanbsb. — Jfanffan-fulphasub-
photphit — MnS,PS. — Sulphide of manganese, prepared by the second
method (p. 218) is introduced into the middle bulb of three, blown on a
barometer tube; then covered with a stratum of protosulphide of phospho-
rus, PS; and the whole exposed to a gentle and continued heat, while a
current of dry hydrogen gas is passed through the apparatus. As the
sulphide of manganese becomes heated, it combines with the sulphide of
phosphorus, and disengages so much heat, that a portion of the latteir
distils right and left into the outer bulbs. The sulphide of phosphorus
which passes over on the side of the hydrogen apparatus is graiiually
conveyed back, with the hydrogen gas, to the sulphide of manganese, and
saturates it completely. After the whole of the sulphide of phosphorus
has been driven over, tibe apparatus is left to cool, the stream of hydrogen
being still kept up. (Vid. II., 213, 214.)
The compound is yellowish-green, and yields a powder of simihur
colour; it forms a loosely coherent mass. Wnen heated out of contact of
air, it gives off the whole of the sulphide of phosphorus in the liquid form,
at a temperature below redness, while pure sulphide of manganese remains
behind. When heated in the open air, it bums with a strong phosphorus
flame, leaving pure sulphide of manganese. Dissolves in nydrochloric
acid, with rapid evolution of sulphuretted hydrogen gas, and separation of
an orange-coloured mass of red protosulphide of phosphorus. (Berzelios,
Ann. Pharm. 46, 147.)
VOL, IV.
2S9 MANGANESB,
MAliaANBSB AKO SeLBNIVM.
A. HtDRATBD SbLKNIDB op MaNQANESB, or HrDSOSBIiBNlAtB OF
Manoakous Oxidb.— Manganons aalta give with alkaline flelenides a palo
red precipitate, which aasQinea a darker red tint when exposed to the air,
from deoompoAition of the hjdroeelenio acid and separation of free
seleninm.
B. Sblbnitb of Manoanoits Oxide, or MANGANOire Selenitb.— «
a. Mtmaseleniie, — Soft, white, easily fusible powder, which, in the fused
state, is decomposed only on the admission of air, whereby the protoxide
of manganese is oxidized and the acid expelled. When fused, it attacks
glass more rapidly than the corresponding salts of lime and magnesia^
rendering the glass full of bubbles, eren below the fusing point of the
latter. It is insoluble in water. (Berselius.) % Muspratt prepared this
salt by dissolving carbonate of manganons oxide in selenious acid, and
obtained it in the form of a white gritty powder, which yielded a colour-
less solution with cold^ and a pink solution with hot hydrochloric acid.
C«leaktioii. Muspratt.
MnO 36 .... 52-73
SeO* 56 .... 60-90 50-00
2H0 18 .... 16-37
MnO,8«0< + 2Aq 110 .... 100-00
b. Biselenite. — A crystallizable compound, which dissolyes readily in
water, and, when heated in doee vessels, gives np the second atom of acid.
(Berielins.)
Manqanese akd Iodine.
A. Iodide of Manganese and Hydriodatb of Mangakous Oxide.
•—A solution of manganons carbonate in aqueous hydriodic acid leaves a
white crystalline mass, having a somewhat styptic taste. When kept
from contact of air^ it may be fused without decomposition; but on tne
admission of air, it is resolved into vapour of iodine and manganons oxide.
Deliquesces in the air, and dissolves readily in water, forming a colourless
solution, which on evaporation deposits white needles. The solution
when exposed to the air is slightly decomposed, depositing brown flakes.
Bromine and chlorine, as well as concentrated nitric or sulphuric acid, set
the iodine free. (Lassaigne.)
Calculation. Laasaigne.
Mn 28 .... 18-18 17-62
1 126 .... 81-82 82-38
m im
Mnl i... 154 .... 100-00 100-00
6. Htdriodateof Manganic Oxide. — Very finely pounded peroxide
of manganese agitated with cold aqueous hydriodic acid, yielda a dark
yellowish-red solution, which when heated evolves iodine^ and is rapidly
converted into hydriodate of manganons oxide.
.J
CHL0RID8 OP MANGANESE. 227
C. loDATB OP Manoanous Oxidb, or MANOAKOtJS loDATB.— Precipi-
tated^ on mixinff bigbly concentrated hot solutions ot acetate of manga-
notis oxide and iodate of soda^ in the form of a light red crjstiilline
powder, which is then washed with water and dried. When ignited, it
leares manganoso-manganic oxide free from iodine. Dissolves in about
200 parts of water. (RammeLsberg, Fogg. 44, 558.)
CryftaUis^, Rammelsbeig.
MnO 36 .... 17*82 17-626
ID* 166 .... 8218
MnO,10» 202 .... 10000
Manganese and Bromine.
A. Bromide op Manganese. — 1. Heated manganese powder absorbs
bromine yapour, forming a pale rose-coloured, fused mass. — 2. A solution
of manganous carbonate in aqueous hydrobromio acid, eraporated and
ignited in a glass tube drawn out to a point at the top, leaves a similar
pale rose-coloured mass. (Ldwig.) Bromide of manganese, when ignited in
an open vessel, is completely decomposed, yielding bromine vapour and
manganoso-manganic oxide; with sulphuric acid it evolves hydrobromio
acid gas and vapour of bromine. (Lowig.)
Hydrated Bromide of Manganese, or Hydrobromaie of Manganous
Oxide. — Bromide of manganese is highly deliquescent (Berthemot.)
The hydrated compound may be prepared by dissolving carbonate of man-
ganous oxide in hydrobromio acia (Lowig), or by digesting metallic man-
ganese with bromme and water. (Berthemot.) The solution, evaporated
at a gentle heat, leaves a light red powder ^Lowig); it yields small
needles, which have a pungent taste, and, when heated, first fuse in their
water of crystallization and then dry up to bromide of manganese. (Ber-
themot, Ann. Chim, Phys, 44, 392.) An aqueous solution of bromine
converts protoxide of manganese into black hydrate and bromide of man-
ganese which dissolves. (Balard, J, pr, Chem. 4, 178.)
B. Bromate of Manoanous Oxide, or Manganous Bromatb. — A
solution of manganous carbonate in aqueous bromic acid is decomposed a
few moments after its formation, bromine being evolved, and the whole of
the manganese precipitated in the form of hydrated peroxide. (Rammels-
berg, Fogg. 55, 66.)
Manganese and Culorine.
A. Protocdloridb op Manganese.— 1. Manganese takes fire in
chlorine gas, and is converted into chloride of manganese. (H. Davy.)-—
2. Hydrochlorate of manganous oxide is evaporated to dryness, and the
dry residue heated (Proust, N. Gehl, 3, 429) ; in order to exclude the air,
the residue is heated in a glass tube, sealed at one end and drawn ont to
a fine point at the other (J. Davy, Sehw. 10, 329); or in a current of
hydrochloric acid gas. (Turner.) —3. Hydrochloric acid gas is passed over
carbonate of manganous oxide at the ordinary temperatures of the air at
first, but afterwards at a low red heat. (Arfvedson.) — Again, when
chlorine gas is passed over a strongly ignited mixture of protoxide of
q2
228 MANGANESE.
manganese and charcoal, needles of proiochloride of manganese are formed,
which renuun mixed with the charcoal. (H. Rose, Pogg. 27, 574.)
Protochloride of manganese is rose-colonred (Arfredson, Sehw. 42«
213) ; bnt if any sesqnioxide of manganese is formed, from the admission
of atmospheric air, it acquires a dirtj red or brown tint. It has a crys-
talline-laminated texture ; fuses at a red heat, forming an oily liquid, which
on cooling, again solidifies in a crystalline mass ; it does not volatilize
below the melting point of glass. Taste saline, but not unpleasant
(Proust, H. Davy, Turner.)
Calculatioii. Turner. Arfvedson. Brandes. J.Davy.
Mn 280 .... 4416 43-8 44-25 44*74 46
CI 35-4 .... 55-84 562 55-75 55-26 54
.^ - - I ■ ^ I !!■ ■ !!■ I ■ II II ^
MnCl.... 63-4 .... 10000 1000 10000 10000 100
When heated to redness in the air, it is decomposed (if it contiuns
water) into hydrochloric acid gas and mauffanoso-manganio oxide. (J.
Davy.) No free chlorine is evolved. (GmeTin.) It is not decomposed
by hydrogen gas at a red heat (Arfvedson) ; but by phosphuretted hydro-
gen it is converted into hydrochloric acid and phosphide of manganese.
(H. Rose.) Probably thus:
3MnCl + PH' = 3MnP + 3HC1.
By ignition with sulphur, it is partially converted into sulphide of man-
ganese. (A. Vogel.) With cold oil of vitriol, it rapidly gives off the
whole of its hydrochloric acid, and is converted into sulphate of manga-
nous oxide. (A. Vogel.) From an aqueous solution of the salt, chlorine,
with the aid of heat, precipitates black hydrated peroxide of manganese
(John); hypochlorous acid produces a similar result, with evolution
of free chlorine. (Balard.) Chloride of lime colours the solution, first red
and then violet ; after which, carbonate of potash changes it to green and
precipitates carbonate of lime. (Pearsall.)
HydrcUed Protochloride of Jdanganese, or HydroMoraie of Manganous
Oxide. — 1. The metal dissolves reaidily in aqueous hydrochloric acid, with
evolution of hydrogen gas. — 2. Carbonate of manganous oxide is dissolved
in aqueous hydrochloric acid. — 3. Faraday heats a mixture of strongly
ignited and finely powdered peroxide of manganese with sal-ammoniac,
very slowly, raising the temperature at last to low redness, and dissolves
out the resulting chloride of manganese with pure water. If the peroxide
of manganese is in excess, the other metals mixed with it do not enter
into combination with the chlorine. Before ignition, the peroxide of man-
ganese must be purified from carbonate of lime by boiling in dilute hydro-
chloric acid. To render available for this purpose the solution of proto-
chloride of manganese obtained in the preparation of chlorine from
peroxide of manganese and hydrochloric acid, Everitt (Phil. Mag. J,
6, 193) evaporates it to dryness in a porcelain basin; heats the dry mass,
stirring constantly, till it assumes an ash-CToy colour and no longer
evolves hydrochloric acid — by which means the chloride of iron is partly
volatilized and partly resolved into hydrochloric acid gas and sesquioxide
of iron ; and finally exhausts the residue with water, and filters the solu-
tion ; — or he boils the solution, first rendered neutral by evaporation, with
carbonate of manganous oxide, which precipitates the whole of the iron.
[Oxide of copper may still remain in the solution.]
TERCHLORIDB OF MANGANESE. 229
The salt eiystaUizes with diffioultj — ^best, however, when slowly
evaporated — in rose-coloured (often colourless: FnmherZy Brandat),
elongated, four-sided tables, bevelled at all the edges, and often with the
summits truncated; specific gravity 1*56; taste burning, afterwards
saline. (John.) — The crystalline form is probably the same as that of the
corresponding protochloride of iron (q. v.). — Colourless crystals are ob-
tained, according to Fromherz, by repeatedly precipitating the solution
with carbonate of potash and redissolving the precipitated carbonate in
hydrochloric acid, as mentioned under the head of Manffanous Sulphate.
(p. 222.)
Calcolatioii. Brandes. Gnhftm. Bncholz*
Mn 28-0 .... 28-17 28-081 ^^.^a «^
CI 35-4 .... 35-61 34-68/ - ^^^ ' ^^
4H0 36-0 .... 36-22 37-24 .... 36-12 .... 42
MnCl + 4Aq 99-4 .... 100*00 100*00 .... 100*00
Or:
MnO 36*0 36*22
HCl 36*4 36-72
3H0 27-0 27*06
HiiO,HCl + 3Aq 99*4 10000
The crystals obtained at 0° do not contain more water. (Brandes.)
When placed over oil of vitriol, either in vacuo or in a receiver con-
taining air, the crystals lose 2 atoms of water at ordinary temperatures.
(Graham.^ At 25° they become white and opaque (John); between 25^
and 87° tney give off hygroscopic water with decrepitation, and become
hard; at 37 '^'^ they become tough; at 50*^ semifluid ; and at 87*5'' they
form a mobile liquid which boils at 106^. If the mass be kept for some
time at a temperature near lOO"*, it gives off 28 per cent. (3 atoms) of
water, and leaves a white powder, which retains one atom of water.
(Brandes.)
Solution of Protochloride of Ma7igane$e, — Both the anhydrous and the
hydrated chloride deliquesce rapidly in the air (John), one part of the
crystals absorbing 1*2 pirts of water. (Brandes.) One part of the crys-
tallized salt dissolves at lO'', in 0*66 parts; at 31*25% in 0*37; and at
62*5% 87*5'' and 106% equally, in 016 parts of water. (Brandes.) The
solution has a light rose colour and thin syrupy consistence.
The salt dissolves readily in alcohol (John), but is insoluble in ether
and in oil of turpentine. (Brandes.)
B. Hydrochlorate of Manganic Oxide. — Finely divided maganoso-
manganic or manganic oxide — added by small portions at a time, in order
to avoid rise of temperature— dissolves m cold concentrated aqueous hydro-
chloric acid, forming a brown solution, which slowly becomes colourless
at ordinary temperatures, and more rapidly when heated or exposed to
sunshine — chlorine being evolved and hydrochlorate of manganous oxide
produced : hence the solution dissolves metals as readily as chlorine -water.
It likewise converts sulphurous and hydrosulphuric acids into sulphuric,
and tartaric into carbonic acid. The addition of water in large quanti-
ties precipitates manganic oxide, and gives rise to the formation of pro-
tochloride of manganese. (Forchhammer.)
C. Terchloride of Manganese ? — Sulphuric acid is added to the
green solution of mineral chameleon till the liquid turns red^ aft^r which
230 MANGANESE.
it is evapOTated to dryness,— and the residuei consisting of salivate and
permanganate of potash, is dissolved in oil of yitriol — the solution intro-
duced into a tubulated retort — and fragments of fused chloride of sodium
added as long as coloured vapours are evolved. The copper-coloured or
green vapours which distil over, condense entirely in a tube attached to
the retort, and cooled down to —15° or —20% forming a greenish brown
liquid. The vapours, when brought in contact with moist air in a wide
tuoe, produce a dense, rose-coloured cloud, and form on the sides of the
tube, with formation of hydrochloric acid, a deposit of purple-red per-
manganic acid. (Dumas, Ann. Chim, Phys. 36, 81; also, Fogg. 11, 165;
also, N. Tr, 17, 1, 194.) This compound is probably analogous to
chlorochromic acid. (H. Rose.)
D. Chlorate of Manoanous Oxide.— Known only in solution.
Colourless liquid.
E, Perchloeate op Manoakous Oxide, or Manoanous Perchlo-
BATE.^— Sulphate of manganous oxide is precipitated by perchlorate of
baryta in equivalent proportions — the mixture heated — and the filtrate
left to evaporate in a dry warm place. — The salt separates in long needle-
shaped crystals, which are highly deliquescent and soluble in alcohol.
(Serullas, Ann. Chim. Fhys. 46, 305.)
Manganese and Fluorine.
A. Protofluoride of Manganese. — Deposited on evaporating a solu-
tion prepared from carbonate of manganous oxide and aqueous hydro-
fluoric acid, in small, pale, amethyst-red, ill-defined crystals, or in the
form of a powder of the same colour. Not decomposed at a red heat.
Dissolves in water when it contains an excess of acid. (Berzeliusj tee
also, Unverdorben, If. Tr. 9, 1, 24.)
B. SEsauiFLUORiDE OF Manganesb. — The native hydrated sesqui-
oxide, reduced to fine powder by levigation, is dissolved in aqueous
hydrofluoric acid, and the deep red solution of acid sesquifluoride left to
evaporate spontaneously. Crystallizes in dark brown prisms, which are
slightly transparent, and ruby-coloured bv transmitted light ; the powder
is also ruby. coloured. In small quantities of water it dissolves com-
pletely; but the solution, when diluted or boiled, deposits a basic salt,
whilst an aM saU remains in solution. On cooling, a portion of the for-
mer is rediasolred, if free acid is present in the liquid. Ammonia preci-
pitates from the aqueous solution pure hydrated manganic oxide, free
from all traoea of hydrofluoric acid. (Berzelius.)
C. S$¥en-halves Fluoride of Manganese? — When a mixture of 2
parts of mineral chameleon, or crystallized permanganate of potash, and
1 part of fluorspar, is digested with oil of vitriol in a platinum retort,
it evolves a yellow vapour (or gas), which changes to purple on coming
in contact with the air, provided the air contains moisture. The yellow
vapour corrodes glass, being resolved into fluoride of silicium and per-
inanffanic acid, which covers the glass in the form of a brown layer, and
'dissolves in water with a purple colour. Chloride of calcium exposed to
the yellow vapour, becomes heated and evolves chlorine. The compound
PHOSPHATE OF MAN6AM0US OXIDE AND AMMONIA. 231
is absorbed by water, forming a purple solotion, which contains hydro*
flaorio and permanganic acids. The solution remains unchanged in
stoppered bottles, but, when evaporated, eyolres oxygen gas and hydro-
fluoric acid vapour, and leaves a brown shining residue, from which
water dissolves hydrofluate of maneanous oxide, leaving a black, inso-
Inble, basic salt. The solution also £ssolves copper, mercury, and silver,
(not gold or platinum,) forming salts of hydrofluoric acid, and at the same
time becomes perfectly colourless. (Wdhler, Fogg, 9, 619; see also
Dqmas, Ann. Chim, Phys. 36, 82.)
Manganese and Nitroobn.
A. Nitrite of Manoanovs OxidE;^ or Manoanous Nitrite. —
Deliquescent. (Mitscherlich.)
B. Nitrate of Manoanous Oxide, or Manoanoits Nitrate.-*
Manganese dissolves readily in nitric acid, with evolution of heat and
nitric oxide gas; the peroxide dissolves in hot nitric acid, only when
sugar or some other deoxidizing substance is present to convert the nitric
into nitrous acid; or, according to Scheele, when the mixture is
exposed to the sun's rays, whereby also the nitric acid is resolved into
oxygen and nitrous acid. The salt crystallises with diSBculty in combi-
nation with water, forming white, longitudinally striated needles, which
when heated, rapidly deliquesce, evolving nitric acid in a state of decom-
position and leaving blacK oxide of manganese. They likewise deli-
quesce when exposed to the air, and are readily soluble in water and
alcohol. (John.) The crystals contain 6 atoms of water. (Miilon, GompU
Rend. 14, 905.)
C. Pbrmanoanate of Ammonia. — Permanganate of silver is decom-
posed by triturating it in a mortar with the exact proportion of sal-ammoniac
requirena, and with water ; the solution is then filtered, and evaporated to
the crystallising point. Crystidline system, the right prismatic. Fig. 53;
tf : tt = 102*' 20' j t : t = 102^ Readily decomposed by heat. The solu-
tion, if it does not contain an excess of ammonia, may be evaporated
without decomposition. (Mitscherlich.)
D. Carbonate of Manoanous Oxide and Ammonia. — Mangano»o-
ammanic Carbonate, — When a salt of manganous oxide is precipitated by
potash or carbonate of potash, and carbonate of ammonia is added, the
precipitated hydrate or carbonate of manganous oxide, is quicklv redis-
solved, forming a solution which is white at first, but afterwards becomes
brown and turoid. (Wittstein, Repert. 51, 80.)
E. Phosphate of Manganous Oxide and Ammonia, or Manga-
noBO-ammonic Fkosphate, — A mixture of aqueous protochloride of manga-
nese, free hydrochloric acid, and phosphoric acid or phosphate of soda, is
boiled in a flask, and then supersaturated with ammonia, and the flask im-
mediately corked. The white hydrated phosphate of manflanous oxide first
separated, changes in a few minutes into pearly scales of the double salt,
which is then collected on a filter and washed with water. If the air is
not completely excluded, hydrated sesquioxide of manganese is also pre-
cipitated, and imparts a reddish hue to the doable salt; if once formed,
232 MANGANESE.
howerer, the eomponnd remains unaltered in the air, and may be washed
with water containing air. — White pearly scales, resembling the acetate
of mercnrons oxide. IT Heintz prepares it by dropping an excess of
ordinary phosphate of soda into a cold solution of manganons oxide,
containing sal-ammoniac and a small quantity of free ammonia. Between
110^ and 120°, it loses nothing but hygroscopic moisture. IT
Calculation. Otto* Hdntz.
NH« .• 170 .... 907 .... 916 +3HO 24-51
2MnO 72-0 .... 38-42 ... 37*84 .... 38-35
cPC)» 71-4 .... 3810 .... 37-86 .... 38-37
3HO 27-0 .... 14-41 .... 15-14
NHH>,2MnO,cPO* + 2Aq 187*4 .... 10000 .... 10000 Z 10123
When heated, it erolyes ammonia and water, and leaves 75*7 per
cent, of white [di-pyro]phosphate of manganous oxide. It is decom-
posed, with evolution of ammonia, by a concentrated solution of potash,
but not by ammonia or carbonate of potash. — Dissolves readily in dilute
acids; from the solution, ammonia precipitates phosphate of manganous
oxide, which, however, is soon reconverted into the double salt. It does
not dissolve in water or alcohol, not even at a boiling heat. (Otto, Schw^
66, 288.)
F. Ammonio- SULPHATE OP Manoaxous Oxidb.— 100 parts of
anhydrous sulphate of manganous oxide very slowly absorb 43*68
parts of dry ammoniacal gas, and crumble to a white powder. This
powder, if preserved in a sealed glass tube, becomes brownish white
after a while. — Gives off part of its ammonia when exposed to the air,
and the whole when ignited. When this salt is dissolved in water^
hydrated manganous oxide separates from it. (H. Rose, Fogg, 20, 148.)
Calculation. H. Boae.
MnO,SO» 76 .... 6909 69*60
2NH» 34 .... 30-91 30*40
MnO,SO» + 2NHS .... 110 .... 10000 10000
G. Sulphate of Manganous Oxide and Ammonia. — Manganow-
amnionic Sulp?iate, — Prepared by mixing sulphate of manganous oxide
with sulphate of ammonia in solution, and evaporating to the crystal-
lizing point. (John.) A mixture of manganous sulphate and sal-ammoniac
likewise yields crystals of the double salt, hydrochlorate of manganous
oxide and ammonia remaining in the mother-liquid. (A. Vogel, /. jPn
Chem. 1, 195.) — The compound forms pale rose-coloured transparent
crystals, which, according to Mitscherlich, have the same form as the
double sulphate of magnesia and ammonia. (Fig, 84.) — Between 75^ and
87°, the crystals lose a portion of their water of crystallization; at a red
heat, the whole of the water is driven off, together with the sulphate of
ammonia. (A. Vogel.) They dissolve readily in water, and deliquesce
in moist air. (John.) They are not precipitated by ammonia, if air be
excluded.
Calculation, according to Mitscherlich.
NH'
MnO
2SO»
7HO
NH*0,SO» + MnO,SO* + 6Aq. 229 ZZ 100*00
14
6*11
72
31*44
80
34-94
63
27*51
MANGANATB OF POTASH. ^33
H. SuLPHATB OF Mangahio Oxide AMD Ammonia.— i/an^ano-
ammonie Sulphate.''^Amnionia Manganue-^dum, — Finely divided peroz^
ide of maoganese is gently heated with oil of vitriol, and the red solu-
tion mixed with sulpmite of ammonia and left to crystallize. Dark red,
regnlar octohedrons, which crystallize only from a very acid solution, and
when dissolved in water, are decomposed, with separation of manganic
oxide. (Mitscherlich.)
CalcnlatbD, acoording to Mitsdierlich.
NH» 17 3-53
Mn*0" 80 16-60
4SO" 160 33-19
25HO 225 46'68
NH<O,SOS + Mn>0>,3SO* + 24Aq 482 lOO'OO
I. Htdrochloratb of Manoanous Oxide and Ammomta.—- i/ait-
ganoBO^amvMnic Hydrochlorate. — Prepared hy mixing hydrochlorate of
manganous oxide with sal-ammoniac. — Crystallizable. — Ammonia does
not precipitate the aqueous solution, if air is perfectly excluded ; on its
admission, however, the liquid first becomes tnrbid and white, and then
brown, and lastly deposits tne manganese in the form of hydrated sesqui-
oxide ; the greater the excess of ammonia, the more complete is the pre-
cipitation. (Vid. Hatchett, Sckw. 14, 352.) f Prepared by Hautz
{Ann. Pharm. 66, 286), by mixing 2 parts of protochloride of manga-
nese with 1 part of sal-ammoniac in solution, and setting aside to crys-
tallize.— Pale red salt, soluble in 1^ parts of water at ordinary tempe-
ratures, and having the same crystalline form as the magnesia*salt. IT
The hydrate, carbonate, and phosphate of manganous oxide dissolve
in a solution of sal-ammoniac. (Brett.) The solution yields a flesh*
coloured precipitate with hydrosulphuric acid (Brett), and gradually
becomes turbia when left to itself, that of the hydrated protoxicte
depositing a brown precipitate. (Wittstein.) The solution doubtless
contains the above-mentioned double salt, together with caustic ammonia,
or carbonate or phosphate of ammonia. The hydrate, carbonate, or phos-
phate of manganous oxide, behaves in a similar manner with sulphate
or nitrate of ammonia.
Mamqanbsb akd Potassium.
A. Manoamate of Potash. — Mineral Chameleon. — Formed when
any oxide of manganese is ignited with hydrate of potash, carbonate of
potash, nitre, or a mixture of potash and chlorate of potash. In the
two latter cases, the oxygen required for the formation of the manganic
acid, is furnished by the nitre or the chlorate of potash; when the
hydrate or carbonate is used, the oxygen is derived from the air; or if
air is excluded, and peroxide of manganese used, one portion of that sub-
stance yields the required quantity of oxygen to another portion, and is
itself reduced to the state of manganoso-manganic oxide. According to
Chevillot & Edwards, a mixture of 44 parts of peroxide of manganese
with four times its weight of hydrate of potash, ignited in oxygen gas,
absorbs from 9 '4 to 10*4 parts of oxygen, or rather more than one atom;
probably, however, the peroxide of manganese used by those chevniots
2S4 MANGANESE.
WM mixed with sesqoioxide. — The green colour of potash or carbonate
of potash, into which portions of adi fiill during fusion, arises from the
formation of manganate of potash.
Preparation, — One part of yenr finely pounded peroxide, or some
other oxide of manganese, is ignitea with 8 parts of nitre, or in an open
ressel with 2 parts of hydrate or carbonate of potash, till a small portion
of the mass taken out as a sample, and allowed to cool, dissolyes
almost wholly in water, forming a dark green solution. When nitre is
used, the mixture becomes semi-fluid during ignition, and finally assumes
a pasty consistence. — In this manner Mineral Chameleon (ChanuBleon
minerale) is obtained ; it is a blackish green substance, which yields a
dark green powder, and, besides manganate of potash, may contain man-
ganic oxide, potash, and carbonate, and nitrite of potash.
To obtain the pure crystallized salt horn this substance, it is dissolved
in a small quantity of pure water, the solution decanted from sesqui-
oxide of manganese, and eyaporated in yacuo oyer oil of yitriol. It
forms green crystals of precisely the same form as sulphate of potash.
Fiff. 76; y :y»=121^ lof ; y : A=119« 24^'. (Mitscherhch.)
CrytiaUized. Or : If itookerlich.
KO 47-2 .... 47*M 8KO 141-6 .... 47-58 .... 46-34
lfnO> 62-0 .... 52-42 lilnK)^ 1160 .... 38-98 .... 88-12
50 40-0 .... 1844 .... 14-50
KO,MnO".... 99-2 .... 10000 3(KO,MiiO>) 297-6 .... 100-00 .... 9896
The crystals, when boiled with a small quantity of dilute nitric acid,
deposit hydrated peroxide of manganese and evolye 8*7 per cent, of
oxygen. They are decomposed by water, yielding a red solution of
permanganate of potash ana a brown ciystalline compound of peroxide
of manganese and potash, which almost immediately giyes up its potash
to the water, and leayes pure hydrated peroxide of manganese. (Mitsoher«
lich.)
8(KO,MiiO^ ^ KO,H]M7 + 2KO + Mn03.
This decomposition appears to result from the affinity of water for
potash, by which two-thirds of the alkali are removed from the salt. The
crystals dissolye without decomposition in an aqueous solution of potash,
forming a green solution, from which they are again separated, togetherwith
free potash, by evaporation in vacuo. But if the solution in potash is exposed
to the air, it turus red from absorption of carbonic acid, and deposits in-
soluble peroxide of manganese. (Mitscherlich.) The mineral chameleon —
inasmuch as it contains an excess of potash—forms with water a solution
which is dark green at first, but rapidly changes through blue, violet, and
purple to carmine-red, in proportion as the exoess of potash is removed
m>m the salt by the water— especially when it is added in large quantities
or when it is hot — and by the carbonic acid of the air; for the same
reason, also, sulphuric acid, nitric acid, carbonate of ammonia, &o. produce
the red colour. (Chevillot & Edwards.) A solution of mineral chameleon
in boiled water, even when kept in air-tiffht bottles completely filled with
it, gradually turns red — showinff that the affinity of the water for the
potash is of itself sufficient to decompose the salt : a small quantity of
peroxide of manganese is precipitated at the same time. (Fromhen.)
W hether the green solution is reddened by spontaneous decomposition, or
by the action of carbonic acid, nitric acid, &c., the change of colour is
PERMANGAKATE OF POTASH. 835
inT«riably accompanied bj pzecipitation of peroxide of manganese.
(Forchhanuner.)
B. Permanoanatb of Potash. — 1. One part of peroxide of manga-
nese is ignited with one part of hydrate of potash (or 1*8 of nitre); the
resulting mass dissolved in water ; and the red solution decanted and evapo-
rated, rapidly at first till small needles appear^ and afterwards cautioasly,
so that the crystallization may go on regalarly. (Ohevillot d^ Edwards.)—
2. Chlorate of potash being kept in a state of fusion over a spirit-lamp,
hydrate of potash is first added to it, and then an excess of finely divided
peroxide ot manganese, which immediately dissolves, forming a splendid
green solution. The mixture is then heated till the whole of the chlorate
of potash is decomposed; and the mass when cold is boiled with a small
quantity of water, whereupon the green colour of the solution changes to
red; finally, the liquid is aecanted from the peroxide of manganese while
still hot, and set aside to crystallize by cooling. The mother^liquor of
the permanganate of potash yields crystals of chloride of potassium, and
if the chlorate of potash has not been completely decomposed, crystals of
this salt are likewise obtained, of a beautiful red colour, arising from
the presence of permanganate of potash. (Wdhler, P<>gg. 27, 626.)
Gregory {J, Fharm, 21, 312; also Ann. Pharm, 15, 237) adds to a finely
divided mixture of 8 parts (3 atoms) of peroxide of manganese and 7
parts (1 atom) of chlorate of potash, a solution of 10 parts (3 atoms) of
hydrate of potash in a very small quantity of water; evaporates to dry-
ness, during which a small quantity of mineral chameleon is formed;
ignites the finely pounded mass in a platinum crucible over a spirit-
lamp, till the whole of the chlorate of potash is decomposed (for which a
low red heat is quite sufficient); reduces the semi-fused mass to coarse
powder; boils it in a larger quantity of water; allows the insoluble
portion to subside and decants; evaporates the clear solution rapidly;
again decants from the freshly precipitated peroxide of manganese; and
leaves the solution to crystallize by cooling. The crystals are then
washed with a small quantity of cold water; dissolved m the smallest
possible quantity of boiling water; and the solution left to crystallize by
cooling. In this manner, needles are obtained | inch in length, and amount-
ing in weight to about a third of the peroxide of manganese employed.
If it be desired to filter the solution, m order to avoid the loss arising
from decantation, a funnel may be used, having its neck filled with asbestos.
The salt crystallizes in dark purple needles, having first a sweet, and
afterwards a rough taste; it does not redden turmeric, and is permanent
in the air. (Chevillot k Edwards.) It belongs to the right prismatic
system of crystallization. Fig. 53, t* : tt' = 103** If; t : i = 101* 404'.
(Mitsoherlich.)
Calculation. Mitsoherlich. Unverdorben.
KO 4^2 .... 29-65 .,., 30-385 .... 25-63
MnW 1120 .... 70-35 .... 69580
KO,Mn«Cy .... 159-2 .... 100-00 Z. 99*965
The crystals decrepitate when heated, evolving 10*8 per cent, of oxygen
gaa, and are convertea into a black powder from which water extracts
manganate of potash, and leaves 54 per cent, of black manganic oxide.
When heated in an atmosphere of hydrogen gas, they become red-hot and
diminish in bulk, at first rapidly, afterwards slowly, with formation of a
green mixture of hydrate of potash and protoxide of manganese. One
gramme of the crysUls absorbs in this process 35*55 centilitres of hydrogen
236 MANGANESE.
gas (or 1 grain absorbs 1 cnbio inch). The crystals detonate when mbbed
up with phosphoras, and the violence of the detonation is increased by heat;
they also detonate with snlphur, bat less powerfally, and only partially by
trituration. A mixture of the crystals with charcoal does not take fire when
rubbed in a mortar, but when heated it burns like tinder; they likewise
detonate with arsenic and inflame with antimony on the application of heat.
Lycopodium mixed with the salt takes fire on the addition of oil of ritrioL
The crystals dissolve in oil of vitriol without efiervescence, forming an
olive-green solution; in this solution, decomposition takes place very
slowly; the addition of a small quantity of water changes its colour to
light green; a larger quantity to orange yellow; and a still larger quantity
to scarlet. An aqueous solution of phosphoric acid, of specific gravity
1*80, likewise dissolves the crystals slowly, forming also a green solution.
The other mineral acids, whose specific gravity is lower, and sulphuric
acid when reduced to the density of 1 '60, produce a red solution, whicb^
in various lengths of time (in a few hours with concentrated nitric acid,
and after some months with dilute nitric acid) gives off oxygen gas, with
effervescence, and deposits a brown flocculent precipitate, tne liquid itself
becoming colourless. ^Chevillot & Edwards.) An aqueous solution of
the salt mixed with nitric or sulphuric acid, evolves bubbles of oxygen
gas, slowly at a temperature of 30°, but rapidly when boiled, hydrated
peroxide of manganese being at the same time precipitated. (Mit-
scherlich.)
The crystals dissolve in 16 parts of water at 15^ ^Mitscherlich.)
The light purple colour of this solution changes, through violet and blue^
to green on the addition of potash; a large quantity of the alkali is how-
ever necessary, unless the mixture is continually shaken; and the Quantity
required is greater, the more dilute the solution and the higher the tem-
perature. A green solution turned red by boiling, continues red on
cooling, but recovers its green colour when shaken; a green solution when
evaporated turns red^ in consequence of the elevation of temperature, and
then green again, from loss of water; the last-mentioned green solution
sometimes yields red crystals. (Chevillot & Edwards.) Perfectly pure
potash does not change tne colour of the red solution to green, except on
the addition of a minute quantity of alcohol; a larger proportion of alcohol
decolorizes the solution and precipitates peroxide of manganese. Car-
bonate of manganous oxide, suspended in solution of potash, likewise
changes the red solution to green, and is itself converted into a salt of
manganic oxide. (Forchhammer.) If the red crystals are dissolved in
solution of potash, and the solution left to evaporate in vacuo, red crystals
are again obtained, a small portion only being decomposed. But a veiy
dilute solution of the salt in caustic potash slowly becomes green at
ordinary temperatures, and more quickly when heated. In order that the
red salt may be completely changed into the green, the quantity of the
aqueous solution must be sufficient to absorb the oxygen gas set free by the
conversion of the permanganic into manganic acid. The green solution
is again reddened by acids, with separation of hydrated peroxide of
manganese. (Mitscherlich.) The red solution of the crystals is also
turned green by solution of soda, by baiyta, and strontia-water, and even by
lime-water; in the last case, however, the effect is but slight, in consequence
of the great dilution of the liquid. In these cases, double salts of mauffOr
nic acid appear to be formed, inasmuch as mansanate of baryta, for
instance, is not soluble in water by itself, and nevertneless no precipitation
takes place. (Chevillot St Edwards.) The red aqueous solution may be
preserved unchanged if kept from the action of deoxidizing substances; in
SULPHIDE OF MAKOANESE AND POTASSIUM. 237
tbe contrary case, the manganic acid loses oxygen and is precipitated as
hydrated [jper] oxide in brown flakes, the solution at the same time
becoming colourless, and, if deoxidized by organic substances, saturated
with carbonic acid. (Chevillot & Edwards.) Sulphurous acid gives
rise to the formation of sulphuric acid and protoxide of manganese.
(Cheyillot & Edwards.) Hydrosulphurlc acid in excess decolorizes
the solution, precipitating pale red hydrosulphate of manganons oxide,
and forming sulphurous acid. Ammonia erolyes nitrogen gas and
precipitates hydrated peroxide of manganese. Nitric oxide throws
down hydrated peroxide of manganese and forms nitrate of potash.
Arsenious acid colours the solution brown or brownish-yellow, ac-
cording to its degree of dilution, and after some time decolorizes it,
throwing down a brown precipitate. Arsenite of potash, according to
Bonnet {Pogg, 87, 303), precipitates a brown oxide of manganese.
Mercury also decolorizes the solution, itself becoming oxidized. (Cheyillot
& Edwards.) All organic substances exert a deoxidizing action on the
solution. Alcohol acts with peculiar rapidity; gum, sugar, paper {e,g,
when used to filter the solution) act more slowly. Decolorization also
takes place when the liquid is exposed in open yessels, organic particles
falling into it from the air, and carbonic acid, at the same time combining
with the potash. Hydrate of potash purified by alcohol, and conse-
anently containing organic matter, and carbonate of soda which has been
frequently filtered through paper, likewise act as deoxidizing agents.
(Cheyillot & Edwards.) — Tartaric or racemic acid, supersaturated with
potash, rapidly decolorizes the solution, firsts however, imparting to
it a transient green colour; citric acid supersaturated with potash,
slowly changes the red solution to green, which latter colour remains
permanent for a considerable time. (H. Rose, Fogg. 59, 320.)
Permanganate of potash crystallizes in all proportions with perchlo*
rate of potash, with which it is isomorphous ; the latter salt crystallizes
in splendid red crystals, when a small quantity of permanganate of pot-
ash is added to its solution. With equal parts of the .two salts, the
crystals are nearly black. (W5hler.)
IT C. Sulphide of Manoanesb and Potassium. 3MnS + KS. —
1. Prepared by fusing anhydrous sulphate of manganons oxide with \ of
its weight of lamp-black, and 3 times its weight of carbonate of potash
and sulphur. A gentle heat is applied at firsts till the carbonic acid is
expelled and the sulphide of potassium fermed ; afterwards the heat is
raised to bright redness. On cooling, a perfectly fused mass is obtained,
which, after the excess of sulphide of potassium has been removed by
cold boiled water, leaves large dark red scales collected together in
masses; these masses maybe readily split, like mica, into thin, trans«
parent, dark-red laminoB. — 2. By substituting peroxide of manganese for
the manganous sulphate, a similar compouna is obtained, but of less
brilliant colour. — The scales, when moist, are rapidly oxidized in the air,
becoming black and opaque, but, when perfectly dry, they remain per*
manent for a considerable time. They are nearly insoluble in water,
alcohol, and ether. They detonate violently with nitre. Acids dissolve
them, with rapid evolution of hydrosnlphuric acid gas. When heated on
platinum wire, they become covered with a green powder of oxysulphide
of manganese. They are gradually resolved by water containing air,
into sulphate of potash, sulphide of potassium, and manganous hyposul-
phite, which dissolve, and an insoluble mixture of sulphur and manganic
oxide. (Volker.) IT
238 MAKQAMBftS.
Ciaoakti<m. yaiker.
3Mn 84-0 .... 44*46 .... 4474
K 89-2 .... 21-02 .... 20-48
4S 640 .... 34-52 .... 3309
SMnS-f^KS 187-2 Z 10000 Z 98-31
D. SvLPHATB OF Mamoakoits OxiDB AND PoTASH. — ManganoiO'
potattie Sulphate. — Pale red crjBtals hanng the form of sulphate of
magnesia and ammonia. {Fig. 64.) (Mitscherlioh.)
CalcvUitiony aooordlBg to KitKfaerlidi*
KO ., 47-2 .... 21-73
MnO 360 .... 16-57
2SO" 80-0 .... 36-84
6H0 54-0 .... 24-86
KO,SOS-i-MnO,SOS+6Aq. 217*2 .... 10000
E. Sulphate of Manganic Oxide and Potash, or Manganoui-
potamc StUphcUe. — Potash Manganete-alum, — A mixture of manganic
sulphate in excess, with a saturated solution of sulphate of potash, is
evaporated at a f^entle heat to a syrupy consistence, and then left to cool
slowly; dark violet^soloured regular octohedrons are then deposited.
The salt is decomposed when reaissolved in water, and on evaporating
the solution, sulphate of potash alone crystallizes out (Mitscherlich.)
Calculation, according to Mitscherlich.
KO
47-2
9-38
Mn'O* ...
800
15-90
4SO*
1600
31-79
24HO ...
216-0
42-93
KO,SO» + Mn*0»,3SO»+24Aq 503-2 100 00
F. Fluoride of Manganese and Potassium. — Manganous sulphate
precipitated by fluoride of potassium, yields a white precipitate, which
IS insoluble in water, but dissolves with tolerable facility in acids (Oay-
Lussac & Thenard); according to Berzelius, this precipitate is a com-
pound of fluoride of potassium with fluoride of manganese.
Manganese and Sodium.
A. Manoanate of Soda. — On igniting peroxide of manganese with
an e^ual weight of hydrate of soda, oxygen gas is absorbed, and a
blackish mass produced, which dissolves in water, forming a green solu-
tion which rapidly changes to red. (Chevillot k Edwards.) — This salt is
BO rerj soluble m water, that it cannot be purified by crystaUisation.
(Mitscherlich.)
Before the blowpipe, carbonate of soda fuses with manganic oxide
on platinum foil or platinum wire, forming a dark bluish grreen mass;
one part of manganic oxide is sufficient to impart a distinct green colour
to 1000 parts of carbonate of soda. (Berselius.)
B. Permanganate of Soda. — ^Formed in the aqueous solution of
manganate of soda; it does not yield distinct crystals when evaporated.
(Chevillot & Edwards.)— Deliquescent (Mitscherlich.)
MAN6ANESB AND SODIUM. 239
G. and D. Tbe oxides of manganese dissolve in fused horas^, forming a
dark amethyst-red glass, which l)eeomes colonrless in the inner flame. —
They behare in a similar manner with microcomtic talt, excepting that the
glass so formed is of a less intense colonr, and more rciidily decolorized in
the inner flame. Nitre immediately restores the red tint to the colonr-
less glass formed in the inner flame. (Berzelins.)
E. SuLPRTDB OF Manoaubsb AND SoDiiTM.— *1. A mixtnre of 10
parts of ignited manganons snlphate with 5 parts of fnsed GUnber^s salts,
heated to whiteness m a charcoal crucible, yields 7*8 parts of a compound
which contains 26 per cent, of sulphide of sodium, and has a light
brownish-red colour, without metallic lustre ; it is dense, has a granular
fracture, and fuses at 60** Wedgewood. (Berthier, Ann. Chim. rhyn. 22,
247.) IT 2. Obtained in a simUar manner to the potassium compounds-
Small, shining, light-red needle-shaped crystals, resembling those of sul-
phide of manganese and potassium in most of their properties, but more
readily oxidable. When treated with distilled water, they rapidly become
opaque and dark-coloured. If in this state they are placed over oil of
vitnol in vacuo, they rapidly absorb oxygen as soon as they become
moderately dry; and the absorption is attended with so violent a disen-
gagement of heat, that the crystals frequently take fire and burn like
a pyrophorus. (Volker.)
3Mn
Na
4S
Calculation.
840 ... 48-6
23-2 ... 13-6
640 ... 37-8
Volkcr.
4911
13-26
3718
3BfnS + NaS 171-2 ... 1000 99-65 \
F. Sulphate of Makoanous Oxide akd Soda. — Man^ano9(h9odte
Sulphate, — If the residue obtained in the preparation of chlorine from
peroxide of mansanese, common salt, and sulphuric acid is ignited, and
afterwards dissolved in water, and the solution evaporated, crystals of
sulphate of soda are obtained. The mother-liauid decanted from these
crystals, if left in a cool place for a year, deposits crystals of the salt P;
and the mother-liquor then remaining, yields, on further standing, large
crystals of the salt a.
a. Birhpdrated, — Obtained by the above method, or, according to
Arrott {Ann. Fharm. 52, 243), by evaporating a solution of the two
salts in equivalent proportions, at a temperature of 50^. — Crystallizes in
transparent, light yellow, oblique rhombic prisms, with the acute lateral
edges trunoat^.^-Not efflorescent
NaO 31-2 ... 18-88
MnO 36-0 ... 21-79
2S0» 800 ... 48-43
2H0 18-0 ... 10-90
NaO,SO> + MnO,SO*+2Aq 165-2 ... 10000
Or: Geigcr.
NaO,SO" 71-2 .. 43*1 42*00
MnO,SO« 760 ... 460 4417
2H0 180 ... 10-9 10-83
16?2 ... 100-0 ~ 97-00
240 BiANGANESE.
fi. Sexhydnxted. — Cxystallixes in transpareniy pale rose-coloured
oblique rhombic prisms, often having their summits and lateral edges
tmncated. [The similarity of the crystalline form would lead to the
supposition that this salt is isomorphous with the sulphate of manganous
oxide and potash, and, like that salt, contains not 5, as Geiger asserts,
but 6 atoms of water; the salt examined by Geiger, as he himself
obserred, was mixed with the salt «.] — This salt reddens litmus slightly,
and has at first a cooling, bitterish, and afterwards an unpleasant,
strongly metallic taste. It effloresces in a warm atmosphere, with the
exception of any crystals of salt at that may be enclosed within it.
•—Decrepitates slightly when heated, swells up to a white porous mass,
and, at a low red heat, fuses to a whitish grey majss, which is still per-
fectly soluble in water. If the ignition be carried beyond a certain
point, a portion of manganoso-manganic oxide is left on dissolyiug the
residue in water.
NeO
31*2 ... 16*23
36*0 ... 1873
80*0 ... 41*62
45*0 ... 23*42
Geiger.
170
MnO
19-0
2SO»
5H0
42*5
21*0
NaO, SO> 4- MnO, S0> -r 5 Aq.
NaO
MnO
2SO«
OHO
192*2 ... 100*00
Probably more nearly.
31-2 15*51
360 17*89
«0*0 39-76
54*0 26*84
99*5
+ 6Aq 201*2 100*00
The salt /3 dissolves in 1*2 parts of boiling water, and the solution
deposits nothing on cooling, either in covered or open vessels, or on
being shaken ; but if, after twenty-four hours, a crystal of the same salt
is introduced into the solution, there is deposited, in about three hours, a
thick ish mass, which, when pressed, is resolved into crystallized sulphate
of soda, and a mother-liquid which holds manganous sulphate in solution.
The salts a and fi both deliquesce in moist air. (Geiger, Mag, Fharm,
11, 27.)
G. Fluobidb of Manganese and Sodium.— -This compound dis-
solves with difficulty in water. (Berzelius.)
H. Pyrophosphate of Manganous Oxide, Soda, and Ammonia.
—When ignited phosphate of soda is dissolved in water, and the solu-
tion mixed with manganous phosphate and free ammonia, a flocculent
precipitate is formed, which rapidly changes into a yellowish white
cr3rBtalline powder; the precipitate must be washed with cold boiled
water. The powder is permanent in the air, evolves water and ammonia
when heated, and leaves a greyish white, pasty, fused mass, the solu-
tion of which reddens litmus. A concentrated solution of potash decom-
poses the salt with evolution of ammoniacal gas; when boiled with
strong nitric acid, it deposits peroxide of manganese, and on evaporation
yields red prisms,' probably consisting of permanganate of soda [or
phosphate of manganic oxide?] It is insoluble in water and alcohol, but
dissolves readily in acids, even when dilute. (Otto, J, Pr. Chem. 2, 418.)
MANGANESE AND BARIUM. 241
Calculation. Otto.
NH> 170 ... 5-21 4-90
N»0 31-2 ... 9-57 7-90
2MnO 720 ... 22-09 2237
2ftPO» 142-8 ... 43-80 4437
7HO 630 ... 19-33 20-46
NH<0,MnO, *P0» + NaO^MnO, *P0» + 6Aq. 3260 ... 100-00 100-00
Manqamese and Lithium.
Permanoanatb of Lithia. — Crjstallisable. (Mitacherllch.)
Manganese and Barium.
A. Manoanate of Baryta. — 1. Peroxide of maDganese, intensely
ignited with an equal weight of bairta, absorbs oxygen, and yields a
oark grey mass, insoluble in water. (Uhevillot 8c Edwards.) — 2. A mix-
ture of peroxide of manganese and carbonate of baryta, exposed to the
strongest heat of a blast-furnace, yields a crystalline mass, in the fissures
of which small four-sided prisms are found. (Abich, Fog^. 23, 338.)—
3. By igniting peroxide of manganese with nitrate of baryta, and washing
the resulting mass with boiling water, an emerald-green powder is
obtained, which, when dry, is permanent in the air. (Forchhammer.)— «
The manganate of baryta, prepared by igniting one part of peroxide of
manganese with 2jparts of nitrate of baryta, is of a pale green colour,
(Fromherz.) — 4. When hydrate of baryta is dissolved in fns^ chlorate of
potash, finely divided peroxide of manganese then added, and the resulting
mass cooled, pounded, and exhausted by boiling in water, manganate of
baryta remains behind in the form of a powder having a fine green
colour. (Wohler, Fogg. 27, 628.) — 5. An aqueous solution of perman-
ganic acid, mixed with baryta-water in excess, deposits, after a short
time, a bluish green powder. (Fromherz.) When baiyta-water is added
to an aqueous solution of permanganate of baryta, and the mixture left
to stand in a vessel half filled with it, green insoluble crystals of man-
ganate of baryta are formed on the sur&ce. (Mitscherlich.)
B. Permanganate of Baryta. — Permanganate of potash is not
decomposed by chloride of barium. (Mitscherlich.) — ^Manganate of baryta
difi'used in water is decomposed by a current of carbonic acid gas, and
the solution filtered and evaporated to the crystallizing point. (Fromherz,
Wbhler, Mitscherlich.) — This salt crystallizes in ueariy black needles,
which are permanent in the air, and have exactly the primary and
secondary forms and the angles of anhydrous sulphate or seleniate of
soda. (Mitscherlich.) The red solution yields with a small quantity of
baryta-water, a violet-coloured liquid, which loses its alkaline reaction
after a while, and when evaporated, even at a temperature below 50%
deposits green manganate of baryta. (Fromherz.) — An aqueous solution
of permanganate of potash yields, with baryta-water, a violet -coloured
mixture, which afterwards becomes colourless, and deposits a blue preci<
pitate. This precipitate retains its colour after washing and drying, and
when decomposed by dilute sulphuric acid, yields aqueous permanganic
acid and a precipitate of hydrated peroxide of manganese. The blue
colour appears to indicate the presence of a mixture of manganate and
permanganate of baryta. (Gmelin.)
TOl. IV. R
242 MANGANESE.
Manqanese and Strontium.
A. Manoanatb of Strontia. — 1. Prepared hj strongly i^iting a
mixture of equal weights of peroxide of manganese and strontia. Pale
green mass^ insoluble in water. (Cbeyillot & Edwards.) — 2. Fromherz
Ignites one fBJct of peroxide of manganese with two parts of nitrate of
strontia.
B. Prrmanqanate of Strontia. — Deliquescent. (Mitscherlich.)
When an excess of strontiarwater is added to an aqneoos solntion of
permanganic acid, the yiolet colour of the liquid gradually changes to
pale green, without the formation of a precipitate : if a smaller quantity
of strontia-water is used, the solution retains its yiolet colour and soon
exhibits a neutral reaction. (Fromherz.)
Manganese and Calcium.
Lime and nitrate of lime, when ignited with peroxide of manganese,
haye as little tendency as the earths to form a salt of manganic acid.
(Cbeyillot & Edwards, Forchhammer, Fromherz.)
Permanganate of Limb. — Deliquescent. (Mitscherlich.)
Manganese and Magnesium.
Permanganate of Magnesia. — Deliquescent. (Mitscherlich.)
Manganese and Aluminum.
Sulphate op Alumina and Manganous Oxide. — Occurs in the
hydrated state in asbestos-like masses, consisting of transparent, silky
fibres. In tasto and solubility it resembles common alum, but does not
appear to crystallize in octohedrons. (Apjohn, Kane, Fogg, 44, 471.)
MnO
A1»0»
4S0»
Calculation.
86-0 ... 7-62
Bl-4 ... 10-88
1600 ... 33-87
2260 ... 47-63
Apjohn.
7-S3
10-65
32-79
.... 4d'15 ...
108
Kane.
25HO
MgO,SO» ...
47-6
472-4
•..
100-00
... 10000
(MnO,HO,SO»)-h(APO»,3SO»)4-24Aq.— MnO,HO replaces KO in
potash-alum, or NH*0 in ammonia-alum. (ICane.)
Manganese and Silicium.
A. Silicate op Manganous Oxide, or Manganous Silicate.— «. 2>i-
•UiecUe, — a. Anhydrous, — When 2 atoms of manganous oxide are fused
with one atom of silica, crystals are obtained, agreeing with those of
MANGANESE AND SILICIUM. 243
obiysolite. ^ (Berthier, Ann. Chim, Phyz. 24, 355.) The ore from
Franklin in New Jersey, examined by Thomson, and Breithaupt*s
ThephroUe, which, according to Rammelsberg, forms a stitf jrfly with
hydrochloric acid, both belong to this head.
Rammelsberg.
Calculation.
Thomson. Thephroite,
2MnO
72
... 69-9
66-60 68-88
6iQ»
31
... 301
29-64 88-66
Fe20»
• •• • •
0-92 FeO 2-92
HO
• • • • •
2-70 CsO,MgO traces
2MnO,Si03 ...
103
... 1000
99-86 100-46
/3. Hydrated. — HydrosiliccUe of Manganese^ {Sckwarzer Mangan-Jciesel.)
— Amorphous, soft, iron-black substance. When heated, it evolves water,
and becomes lighter in colour. At a higher temperature, it increases in
bulk and becomes still lighter. Fuses in the outer blowpipe flame to a
black, and in the inner flame to a green glajss. (Berzelius.) Dissolves
readily in acids, with separation of siUca.
2MnO
SiO> .
2HO .
Klaproth.
Calculation.
Klappcxnd.
72 ... 59-50
55-8
31 ... 25-62
25-0
18 ... 14-88
130
2MnO,SiO» f 2Aq 121 ... lOOOO 938
h, MonoiiliccUe. — Silicifsrous Manganese, Red Manganese, Sother
Mangankiezel, Boihbraunsteinerz. — This mineral has two planes of cleavage,
which intersect each other at angles of 92° 55^ and S7° V; it is probably
isomorphous with Augite; specific gravity from 3 '5 to 3*6, hardness equal
to that of Apatite. Translucent and rose-coloured. Before the blowpipe
in the inner flame, it yields a turbid rose-coloured glass, and in the outer
flame a black bead, having a metaUic lustre. (Berzelius.)
Berzelias.
Dumas.
At.
a. At.
6.
CaO
... 312 ... I ... 28 ... 14-51
... 14-57
MgO
0*22
FcO 0-81
MnO 1 ... 36 ... 53-73
... 4904 ... 2 ... 72 ... 37-30
... 3606
SiO« 1 ... 31 ... 46-27
... 4800 ... 3 ... 93 ... 48-19
... 48-90
MnO.SiOa 1 ... 67 .. 10000
... 100-38 ... 1 ... 193 ... 10000
... 100-34
In the SUidferous Manganese (a) from Longsbanshyttan, a small
quantity of protoxide of manganese is replaced by lime; in the BvL9tamiU (6)
from Mexico, to the amount of one-third. To this class also appears to
belong Thomson's bisilicate of manganese, in which the protoxide of
manganese is partially replaced by protoxide of iron.
If one atom of SiO' is fused m a charcoal crucible with 2 atoms of
MnO, in a powerful blast-furnace, a great part of the manganese is re-
duced, and after fusing f of an hour, a hyacinth-red glass is obtained,
composed of 62*1 parts of manganous oxide and 87*9 parts of silicic acid
(=dMnO,2SiO* nearly). At a still higher temperature, a larger portion
of the manganese is reduced, and a pea-yellow coloured slag remains, in
which 48*5 parts of manganous oxide are combined with 51-5 parts of
silica (= 4MnO,5SiO* nearly). A mixture of MnO with SiO', when heated
in a charcoal crucible, likewise yields reduced manganese, together with
r2
244 MANGANESE.
a pea-yellow coloured slag; but with the proportion of 2MnO to dSiO%
a porous pea-jellow mass is obtained, without anj reduction of man-
ganese. (SefiBtrOm, J, techn, Chem. 10, 183.)
c, TetratUieaU. — An aqueous solution of tetrasilicate of soda gires a
white precipitate with sulphate of manganous oxide. (Walcker.)
B. Silicate of Manganic Oxidb, or Manganic Silicate.-
TruUicate.^^HeteUrocline, — Oblique rhombic prisms of specific gravity
4*562; colour between iron-black and steel-grey; powder brownish-black.
KO
CaO
At.
240
31
88*56
11*44
St. Maccel.
0*44
0-60
Mn«0»
Pc»0»
SiQ»
3 ...
!!!!!! 1 \\\
85*88
305
10*02
1 ...
271
10000
99*99
5. DmlieaU. — To this head belong the manganese ore from St.
Marcel, analysed by Berzelins, and the SUieiferous Manganese of Tinzen.
The latter is dense, with a granular and somewhat laminated fracture;
hard, black, with &int metallic lustre, and yields a dark brown powder.
When gently heated it loses water, and at a higher temperature gives
off oxygen gas. Dissolves in warm hydrochloric acid, with evolution of
chlorine and formation of a siliceous jelly. Sulphurous acid acts on it
only with the aid of heat, and decomposes it completely, though with
considerable difficulty; an aqueous solution of oxalic acid decomposes the
fine powder completely when boiled with it for an hour.
Berzelins.
At.
SLUareeL
Mn«0»..
!•••«••
. 18
• ••
1440*0
76*60
75*80
Fe«0»..
1 • • • • ••
1
• • •
78*4
4*17
414
APO" ..
1
51*4
2-74
2*80
SiO* ..
!•••■••
. 10
• • •
310*0
16*49
1517
1
• • •
L879-8
... ]
LOOOO
97*91
Sdiwetser. Berthier.
At.
TiBcen.
CaO
• • •
1*70
Mn»0»
19
... ]
15200
• • •
79*65
76*35 ... 77-8
Fe«0»
1
78*2
• ■•
4*10
3-70 ... 1*0
APO«
• « •
trace ... 1*0
SiO*
10
310*0
• •
16-25
15*50 ... 15*4
HO
• ••
2*75 ... 2-8*
1 ... 1908*2 .. 100*00 100*00 ... 98*0
* The 2*8 per cent, in Berthier's aDalysis consists of quartz.
C. Hydrofluatb op Silica and Manoanous Oxide. — MnF,SiF*+
7Aq. — Crystallizes from a highly concentrated solution, in long, regular,
six-sided prisms, — or by slow evaporation, in shorter prisms and rhombohe-
drons. Colour very light red. When distilled, it first gives ofl* 7 atoms
of water and then gaseous fluoride of silicium, leaving fluoride of manga-
nese of the same form as the original crystals. Easily soluble in water.
(Berzelius.)
MANGANESE AND TITANIUM. 245
D. With glass-flnxeSy manganons oxide yields eolonrlesa or pale red
glasses; manganic oxide yields yiolet*red glasses.
E. SiLiCATB OF Glucina AND Manganous Oxide. — Found native,
containing sulphide of manganese, in the form of ffelvine. Tetrahedrons.
Fi^s. Id & 14. Sp. gr. = 3*1. Harder than apatite. Translucent*
yellow, with a tinge of green or brown. In the inner blowpipe flame, it
fuses with ebullition, and forms a turbid yellow bead; in the outer flame
it fuses with greater difficulty, and acquires a deeper colour. Dissolves
slowly in borax, forming a clear glass, which, till the whole of the sub-
stance is dissolved, has a yellowish tinge arising from the presence of
sulphide Of sodium; but after the solution is complete, it appears colourless
in the inner flame, and amethyst-red in the outer. Dissolves more
readily in microcosmic salt, but with separation of a skeleton of silica,
and yields a colourless glass which becomes opalescent on cooling. With
carbonate of soda it first swells up, and then fuses to a black bead, which
becomes brown in the inner flame; with carbonate of soda on platinum,
after long blowing, it yields mineral chameleon. (Berzelins.) Dissolves
in hydrochloric acid with evolution of sulphuretted hydrogen gas and
separation of gelatinous silica.
•
At. C. Gmelin.
GO 3 .... 38-1 .... 13-46 12*03
MnO 3 .... 108-0 .... 38-15 31-82
PeO .... .... 5-56
SiO« 3 .... 930 .... 32-85 33-25
MnS 1 .... 440 .... 15-54 14-00
HO »» ,^ 1-16
1 .... 283-1 .... 100-00 97-82
The glucina is mixed with a small quantity of alumina.— d(GO,MnO,
SiO^+MnS.
F. Silicate op Alumina and Manganous Oxide. — Hydrated, —
KarpkMU. — Fibrous; of specific ^vity 2*93; harder than felspar;
opaque; straw-yellow. When heated it gives oflTwater and afterwards hydro-
duoric acid; swells up before tiie blowpipe, and fuses with difficulty to a
turbid brownish glass, which becomes darker in the outer flame. (Bene-
Uus.) SoEtfcely attacked by hydrochloric aoid«
At.
\>AV^ ............ «... •... . ...... I
MnO 1 .... 36-0 .... 21-51
JcC^vr^.. ••••....•. .... •... .......I
APO» 1 .... 51-4 .... 30-70
SiO" 2 .... 62-0 .... 37-04
HO 2 .... 18-0 .... 10-75
p»» 0,...t. ...... .... ••••
Stromejer.
»
Steinmaim.
0-27
1916
••«•
17-09
2-29
PeO
5-64
28-67
....
26-48
36-16
....
37-53
10-78
....
11-36
1-47
167-4 .... 100-00 98-80 .... 9810
Manganese and Titanium.
TiTANATB OP Manganous Oxide, or Manganous Titanatb.— fl^o-
vtte.— Crystalline system, the doubly oblique prismatic. Fig. 121, with
three angles truncated, as well as the edges between y and w, and l^twe^n
246 MANGANESE.
y and «; y : w = 87** 10'; v :v = SS"* SC; u :v = 110® 35'. Sp. fff. =
d'84; harder than felspar; oark rose-coloured. Infusible before the blow-
pipe; insoluble in hydrochloric acid; disintegrated bj fused bisulphate of
potash. Contains 24'8 per cent, of manganous oxide, 74*5 of titanic
acid; and a trace of lime. (Dufrenoy.) Isomorphous with brown titanite;
has two planes of cleavage, which intersect each other at an angle of
126^ 5&. Specific gravity = 3*527. (Breithaupt.) Contains silica as
an essential ingredient (Piattner); it is therefore TiianiU in which the
lime is replaced bj protoxide of manganese. (Breithaupt.)
Manoanesb and Tantalum.
Tantalide of Manganese. — ^Prepared hj igniting a mixture of the
two oxides in a charcoal crucible. Hydrochloric acid separates the
manganese, and leaves the tantalum in the form of an insoluble black
powder. (Berzelius.)
Manganese and Tungsten.
A. TuNQSTATE OF Manganous Oxide, or Manganous Tungstate. —
a. Mofiotungstate, — Monotangstate of soda added to a neutral salt of
manganoQS oxide throws down a greyish-white powder, which when
heated becomes pale yellow, and loses water ; at a higher temperature, the
whole of the water is expelled, and the salt obtained in the fluid state.
The hydrated powder gives up the whole of its tungstic acid to potash; it
dissolves also in warm phosphoric or oxalic acid, sparingly m boiling
acetic acid, and is insoluble in cold hydrochloric acid. (AnUion.)
MnO
W0»
Ipuied, Anthon.
36 .... 2308 .... 24-72
120 .... 76-92 .... 75-28
MnO....
WO»....
2HO....
Unified,
36 .... 20*69
120 .... 68-96
18 .... 10-35
Anthon.
.... 22
.... 67
.... 11
MiiO,WO»
156 .... 10000 .... 100-00
+ 2Aq.
174 .... 10000
.... 100
h, Bitungstale, — Alkaline bitungstates precipitate from salts of man-
ganous oxide, a while powder which turns yellow ahd loses water wheii
ignited, and is soluble in aqueous phosphoric, oxalic, and nitric acid ; the
latter solution is rendered turbid by boiling, from separation of yellow
tungstie acid. (Anthon, «/. pr. Chem. 9, 339.)
Ignited, Anthon. Unignited, Anthon.
MnO 86 .... 13-04 .... 1319 MnO... 36 .... 1188 .... 12
2WO» 240 .... 86-96 .... 8681 2W08 240 .... 79*21 .... 79
3H0.... 27 .... 8-91 .... 9
MnO,2WO" 276 .... 10000 .... 10000 +3Aq. 303 .... 10000 .... 100
B. BtTLPHOTUNOflTATE OP Manoanesb. — MuS, WS*. — Dissolvcs in
water, forming a yellow solution. (Berzelius.)
Manganese and Molybdenum.
A.^ Moltbdatb op Manganous Oxide. — Molybdate of potash pro-
ducer in a solution of protochloride of manganese, a brownish- white preci-
pitate which is soluble in 40 or 50 parts of water. (Richter.)
MANGANESE AND CHROMIUM. 247
B. StTLPHOMOLYBDATE OP Manqanese.-— a. With excesi of Sulphide
of Manganese* — A solution of 6, or a mixture of a nianganous salt and of
sulphomolybdate of potassium dissolved in water is precipitated by
ammonia. The precipitate is a dark red powder, which becomes browner
on drying. It is further decomposed by an excess of ammonia, whereupon
it blackens from oxidation.
h. In equal numbers of atoms. — Formed by digesting in water a mix-
tare of tersulphide of molybdenum and hydrateid sulphide of manffanese,
the latter being in excess. The brownish-yellow solution obtained dries
up to a transparent unczystallizable yamish. The same compound is
formed, but without precipitation, when a manganous salt is mixed with
an aqueous solution of sulphomolybdato of potassium.
e. With excess of Tersulphide of Molybdenum, — Produced in the form of
an insoluble compound, on digesting sulphide of manganese with excess of
tersulphide of molybdenum, (fierzelias.)
C. Persulphomoltbdate or MANOAKEdE. — Prepared by precipi-
tating a manganous salt with an aqueous solution of persulphomolybdate
of potassium. Red powder. (Berzelius.)
Mangahesb and Vanadium.
A. Vanaditb op Manganous Oxidb> or Manganous Vanaditb.—
Prepared by double decomposition. Brown. When exposed to the aotioi^
of air under water, it assumes a yellow colour, and gradually disappears,
while black crystals of manganous yanadiate are deposited. (Bcrzelius.)
B. Vanadiate op Manganous Oxide, or Manganous Vanadiatb.
•— <r. Monoifanadiate.'^mThe yellow aqueous mixture of vanadiate of am-
monia and protochloride of manganese in excess i^ precipitated by alooholi
and the rusty yellow precipitate washed with the same liquid ; it is then
dissolved in water and the solution left to evaporate spontaueously. The
salt separates in small brownish black crystals, which yield a red powder,
and are sparingly soluble in cold water, forming a yellow solution, from
which they are again precipitated by alcohol.----6. Bivanadiate.—CjjB'
tallizes from an aqueous solution by spontaneous evaporation, in small
red granules. Forms a yellow solution in Water, and is a^n precipi-
tated by alcohol in the form of a yellow powder. Dissolves with difficulty
in cold water, forming a yellow solution. (Berzelius.)
Manganese and- Chromium.
A. Chromide of Manganbse. — 1. A mixture of equal parts of
sesquioxide of chromium and protoxide of manganese exposed to the heat
pf a blast-furnace in a charcoal crucible, yields an alloj which is perma-
nent in the air, insoluble both in hydrochloric and in nitric acid, and dis-
solves only after prolonged boiling in aqua-regia* (Bachmann.)
B. Chromate op Manganous Oxide, or MAirbANOUB Chromatb.— -
a. Dichromaie. — Manganous salts are coloured ydlloMsh brown by mono -
chromate of potash, and yield, after some time, a dark brown precipitate,
which is deposited partly on the sides of the vessel and partly as a pe)^
WaringtoD.
ReiDsch.
5107
50y
3671
37-3
12-20
11-8
248. ARSENIC.
licle on the liquid. If the solution is largely diluted, the deposit has a
crystalline aspect. Under the microscope, the formation of reddish-
brown granules is first obsenred : these go on increasing in size, and after-
wards fine needles are formed, which appear dark chocolate-brown by
reflected, and deep brownish-red by transmitted light. The precipitate
gives up its chromic acid to a boiling solution of potash ; dissolves in
hydrochloric acid with evolution of chlorine, forming a brown liquid,
which is turned green by alcohol ; dissolves also in dilute sulphuric or
nitric acid, forminfi; an orange-yellow solution. (Warington, Fhil. Mag,
J. 21, 380.) Spanngly soluble in water. (Grouvelle; see also Reinsch,
PoS^ff' 55, 97.)
Dried at lOO""
2MnO 72 ... 50-7r
CrO» 52 ... 36-62
2H0 18 ... 1267
MiiO,CrO»+2Aq... 142 ... 180-00 99-98 100-0
h, Monochromate f — Aqueous chromic acid slowly dissolves manganese
with evolution of hydrogen gas; manganous oxide and its carbonate,
however, are more readily dissolved by it. Uncrystallizable, chestnut-
brown liquid, having an acid reaction and pungent metallic taste. After
repeated evaporation, it deposits nearly all the manganese in a higher state
of oxidation. (John.) — ^Neither the monochromate nor the bichromate of
potash precipitates manganous salts immediately; after some time, how->
ever, especially with the monochromate, a brownish black precipitate is
produced. (Thomson.)
Other Gompoukdb of Manganese.
With Iron, Cobalt, Nickel, Copper, and Gold, forming white, brittle^
and very refractory alloys.
CBAnsB XXIV.
AESENIC
Scheele. Opusc. 2, 28; also CreU. iT. Entd. 3, 125.
Bergman. Optisc, 2, 272.
Buchols. Arsenic Acid. Scher. J. 9, 397.— Arsenious Acid. Sckw.
15, 337.
Lauffier. Ann. Chtm, 85, 26.
Fischer. Schw. 6, 236; 12, 155; 39, 364.— iTo^n. Arch. 11, 224.
Thomson. Degrees of Oxidation of Arsenic. Ann. Phil. 4. 171; also
Schw. 17, 422.— Salts of Arsenic Acid. Ann. Fhil. 15, 81 : also
Sohw. 29, 430.
ARSENIC. 249
BerzeliuB. Afin. Chim. Phy$. 5, 179; 11, 225.
Gehlen. Behaviour of Arsenic with Potash. Schw, 15, 501.
Gaj-Lussac. Behayioar of Arsenic with Potash. Ann. Chim, Phyz,
3, 136.
P£Ehff. Arsenic Acid. Sehw> 45, 5*9.
Bnchner. Arsenic Acid. Schw, 45, 419.
Gnibourt. J. Chim, med. 2, 55.
Stromejer. De hydrogenio arsienato. Comment Soc. OoU, 16, 141.
Proust. Arseniuretted Hydrogen. Scher, J, 8, 285,— Sulphide of Arse-
• nic. Scher. J. 9, 287; also €filb. 25, 178.
Th^nard. Sulphide of Arsenic. Ann. Chim. 59, 284; also if. Gehl. 2, 685.
Berzelius. Sulphide of Arsenic and its combinations with other Metallic
Sulphides. Schw. 34, 46. Further: Fogg. 7, 1 and 137.
Dumas. Arseniuretted Hydrogen and Chloride of Arsenic. Ann, Chim,
Phy9. 33, 351; also Pogg. 9, 308.
Dumas. Solid Arsenide of Hydrogen and Arseniuretted Hydrogen gas.
J. Pharm. 16, 335; also, Pagg. 19, 191 ; abstr. Schw. 59, 222.
Graham. Arseniates. Phil. Trans. 1833, 2, 253; alsoPo^^. 32, 33.
Bouquet k Cloez. New Acid containing Sulphur, Arsenic, and Oxygen.
N. Ann. Chim, Phys, 13, 44; J. Pharm. 7, 23; abstr. Ann. Pharm.
56, 205.
Walchner. Distribution of Arsenic and Copper. Compt. rend, 23, 12 j
also Ann, Pharm. 61, 205.
Bussy. Modifications of Arsenious Acid. Compt. rend. 24, 774; Phil,
Mag. «/. 31, 151; Pepert, Pharm, 2nd ser., 48, 301; Ann. Pharm,
64, 286; J.pr. Chem. 41, 340; Pharm. Centr. 1847, 938; J. Pharm,
Chim. 12,821,
Will. Occurrence of Arsenious Acid and other Metallic Oxides in
Mineral Waters. Ann. Pharm. 61, 192.
Pasteur. Chloride of Arsenic. J, Pharm, Chim, 13, 395; abstr. Ann,
Pharm. 68, 307. Salts of Arsenious Acid. J. Pharm, Chim, 13,
397; abstr. Ann, Pharm. 68, 308.
Filhol. Salts of Arsenious Acid. J, Pharm, Chim, U, 331 and 401;
abstr. Ann, Pharm, 68, 308.
Anen, Anenik, Scherhenlobcld, Napekenkobold (OMe^Jiend, Bowl-
sprite), Fly-poiion, Ci^Uum of the dro^iists.
ffietory. Known from very early times, principally in the forms of
sulphide of arsenic and arsenious acid. Brandt, in 1733, made the first
accurate experiments on its chemical nature. Scheele, in 1755, discovered
arsenic acid and arseniuretted hydrogen gas. Sir H. Dayy discovered
the solid arsenide of hydrogen. Berzelius specially investigated the
stoTchimetrical relations of arsenic and its numerous sulphur-compounds.
Sources, Native; as arsenic acid; as arseniate of lime, magnesia, lead-
oxide, ferrous, ferroso-ferric, and ferric oxide, oobaltic oxide, nickel-oxide,
and cupric oxide; as sulphide of arsenic combined with other metallic sul-
phides, as in Grey copper, Tennantite, Light red silver, and Argentiferous
copper-glance; in combination with another metal, in arsenide of manga-
nese, arsenide of iron, arsenide of cobalt, and arsenide of nickel; in ^om-
250 ARSENIC.
blnation with another metal and a metallio sulphide, in Arsenical pyrites.
Cobalt-glance, Nickel-glance, and many yarieties of Antimonial nickel.
Small quantities of arsenic and its compounds are likewise found in other
minerals and products obtained from them, as in sulphur, sulphuric acid,
phosphorus, phosphoric acid, sulphide of antimony and preparations made
from it, and in zinc, tin, and many rarieties of ferric oxide. Traces of
arsenic are likewise found in the Olivine which accompanies the Siberian
meteoric iron (of Pallas) and that from Atacama (not in terrestrial
olivine). (Rumler, Vogg, 49, 591.) IT Walchner ha£ shown that arsenic
(together with copper) is as widely distributed as iron, small quantities
of these metals being invariably found in iron-ores, whether occurring in
ancient or modem formations, in all chalybeate waters and the deposits
formed from them, and in a great variety of ferruginous clays, marls, and
slates. Walchner has likewise demonstrated the ^presence of minute
quantities of arsenic and copper in various specimens of meteoric iron,
viz. in the Siberian meteoric iron above mentioned (Rummler had merely
shewn the existence of arsenic in the accompanying . olivine), in a
Mexican sample from Yuanhuitlan, near Oaxaca; in a specimen from
Tenessee, and in the large mass preserved in the Cabinet of Natural
History of the Yale College, Connecticut. Hence it would appear that
arsenic and copper are sjssociated with iron in the other bodies of the
universe as well as on the earth. {Ann, Pharm. 61, 209.) The presence
of arsenic in mineral waters has likewise been demonstrated by Will
{Ann, Pharm, 61, 192.)ir The statement of Orfila & Couerbe {J, Chim,
med. 15, 462 and 632) that arsenic is contained in the bones and muscular
flesh of a healthy man, and in the bones of a healthy horse, ox, and
sheep, was attacked by Danger & Flandin and by Chevallier {J, Chim.
med. 17, 84), by Barbet, Faur6 & Magouty (/. Chim. med. 17, 654), by
Pfaff {Eepert. 74, 106), by Steinberg (/. pr. Chem. 25, 384), and by
Jacquelain {Compt rend. 16, 30), and has since been retracted by Orfila
himself {Ann. Chim. Phys. 77, 159) as unfounded.
Preparation on the large scale, — By heating arsenical pyrites in
earthen tubes till the arsenic sublimes. — Under these circumstances, the
arsenical pyrites Fe^As,S', is resolved into 2FeS which remains behind
and As which sublimes. The tubes, several of which are laid together
horizontally in the furnace, are 3 feet long and 1 foot wide. A tube,
8 inches long, made by rolling up a piece of iron plate, is inserted for half
its length into the pairt of the earthen tube which projects from the
furnace, and an earthen receiver is luted on to it. The arsenic sublimes
in the iron tube in the form of a coherent, internally crystalline mass,
which, when the whole has cooled, is detached by unrolling the tube.
Puri/ication. — By a second sublimation. — Commercial arsenic is con-
taminated, partly with suboxide and sulphide of arsenic, which are more
Tolatile than the metal itself, partly with fixed impurities, such as earthy
matrix, undecomposed arsenical pyrites, &c. On subliming this impure
arsenic, the suboxide and sulphide volatilize first, and either condense in
the cooler part of the apparatus or escape in the form of vapour, while the
arsenic itself oondenses nearer to the fire. The addition of charcoal
powder is useful. The apparatus consists either of two crucibles placed
one above the other and luted together with clay, the under one, which
contains the crude arsenic, being thrust half-way through a hole in an
iron plate, so that the fire may act only on its lower part; or of a glass
flask half-filled with crude arsenic, and having a glass tube fastened to its
neck with loam, which is afterwards dried : the tube is loosely closed at
ARSENIC. 251
top with a charcoal stopper. The flask is immersed to two-thirds of its
depth in a crucible filled with sand, and the crucible surrounded with
red-hot coals. The arsenic condenses on the upper part of the flask; but,
as the air cannot be completely excluded, it is always more or less con-
taminated with octohedrons of arsenious acid. {Comp. Bette, Ann. Fharm,
8S, 355.) To obtain the arsenic quite free from suboxide and arsenious
acid, it must be sublimed in a wide tube in a stream of dry hydrogen gas.
Small quantities only must be operated upon at once, otherwise the tube
will be stopped up by the sublimed arsenic. On the small scale, also,
metallic arsenic may be obtained by igniting a mixture of arsenious acid
and black flux (III., 20^ in a subliming apparatus of this description, or
by igniting arseniate of lime in a retort through which hydrogen gas is
passed.
Properties. — Crystalline system, the rhombohedral. Form, an acute
rhombohedron. Fiff, 151; t^ : r* = 85° 26'. Cleavage parallel to randp.
A more acute rhombohedron likewise occurs, as also an obtuse rhombo-
hedron, Fig, 141 in which r* : r'rz 114° 26', and one still more obtuse.
(Breithaupt, Fogg, 7, 527; Schw, 52, 168.) According to former state-
ments, and likewise according to that of Elsmer («/. pr, Chem, 22, 844),
arsenic appears to crystallize in octohedrons; perhaps, however, the trun-
cated acute rhombohedron {Fig. 153) was mistaken for that form.
Specific gravity = 5*621, Karsten; 5*672, Herapath; 5*76, Lavoisier;
5*959, Guibourt^ (8*31, Bergman.) Not very hard, but very brittle.
Tin-white, inclining to steel-grey; very bright. Volatilizes at a dull red
heat, without previously fusing. In a glass tube it does not volatilize
even at 294° (561° F.); not even at the melting point of zinc, but begins
to volatilize at a red heat visible in the dark. (Mitchell.) If an attempt
be made to fuse it by heating it in a sealed glass tube, the tube burets^
but no fusion takes place. (Fischer.) Arsenic is a violent poison.
IT According to Berzelius {Ann. Fharm. 49, 247), arsenic exists in
two allotropic states. One of these. As a, is produced when arsenic, in the
state of vapour and mixed with another heated gas, is deposited on a part
of the subliming apparatus which is not very strongly heated. It is
dark grey, crystalline, and oxidizes in the air, especially at 40°, being
thereby converted into blaek pulverulent suboxide. The other modifica-
tion. As 0, is produced when arsenic is very strongly heated, or when it
condenses by sublimation on a part of the vessel the temperature of which
is near the point at which the arsenic volatilizes, so that the metal is
deposited in an atmosphere of its own vapour. This modification is
nearly white, haa a strong metallio lustre, is denser than the preceding,
and remains unaltered in the air^ even though finely pounded and heated
to 70° or 80°, and perhaps even above 100*". These modifications of the
metal appear to be repeated in arsenious acid, which likewise exhibits two
varieties of structure, the crystalline and the vitreous (vid.pp. 254, 255^.
The former of these^ which is produced when the acid condenses on a cold
surface, or when it crystallizes from a hot aqueous solution, appears to
have As a for its radical ; while the latter, which is formed when the acid
sublimes on a strongly heated surface^ is probably derived from As/9.
[May not these so-called allotropic modifications be attributed to difl*erence
of mechanical structure? The circumstances under which the modifica*
tion As /3 is produced admit of slower cooling, and consequently allow the
particles to arrange themselves with greater regularity and compactness :
252 ARSENIC.
hence greater density and greater power of resisting the action of oxidising
agents, &c. Many other cases of cUlatropic modification maybe explained
in a similar manner. (W.)] IT
Compoundi of Arsenic,
Absenic akd Oxygen.
A. Suboxide of Arsenic.
Most metallic arsenic when exposed to moist air at ordinary tempe-
ratures, gradually becomes covered with a black film, and finally crumbles
to. a black powder. Many specimens of metallic arsenic (the denser
Tariety most probably) retain their lustre and solidity when exposed to
the air, and do not increase in weight. (Berzelius, Buchner, Repert, 21,
28; Thomson, Ann, Fhil, 18, ISO.) In dry air, arsenic remains unaltered;
and after long exposure to dry air, it remains unchanged for a louger
time in moist air, probably in consequence of the deposition of foreign
matter (films of organic matter) on its surface. But when exposed in the
fresh state to moist air, its surface soon assumes a bronze colour, and in a
few days becomes covered with suboxide; between 30° and 40°, this
change takes place more quickly. Lumps of the metal, however, never
&11 to pieces, but merely acquire a coating of suboxide. If water con-
denses on the pulverized arsenic, arsenious acid is immediately produced.
(Bonsdorff.)
Properties, — Brownish black; more volatile than arsenic, less volatile
than arsenious acid; in the state of vapour it has an odour of garlic, or
like that of phosphorus. When arsenic is heated in a tube containing
air, by immersion in zinc just solidified after fusion, a white ring of
arsenious acid sublimes, and below it a brown ring of suboxide; and if
the tube be then immersed in boiling mercury, the white ring volatilizes,
but the brown ring remains until it is converted by oxidation into arse-
nious acid^ whereupon it likewise passes off in vapour. (Mitchell.)
Approximate calciilation.
As 75 90-36
8 9-64
AsO 83 100-00
The calculation is based upon the fsust, that 100 parts of pulverized
arsenic exposed to the air, take up at most 8 parts of oxygen, according
to Berzelius, and 11 parts according to Bonsdorfl*.
Proust regards the suboxide as a mere mixture of metallic arsenic
and arsenious acid : if that were the case, however, the oxidation ought
to go on till the whole was converted into arsenious acid.
Decompositions, — When gently heated out of contact of air, the sub-
oxide is resolved into arsenious acid which volatilizes, and metallio
arsenic which remains behind. (Berzelius, Mitchell.) When it is digested
in hot hydrochloric acid, arsenious acid is dissolved, and metal remains
behind. (Berzelius.) Insoluble in water and in cold acids.
ARSBKIOUS ACm. 253
B. Arsenious Acid. AsO'.
Oxide of Anenie, White Arsenic, Flowers of Arsenic, Rat-poison,
HuUenrauchy Oiftmekl, Arsenide Saure, Acide arsenieux, Arsenoxyd,
Oxyde d^ Arsenic.
i^ormo^km.— Arsenic^ heated in the air till it Yolatilizes, bamB with
a reddish smoke having the odoor of garlic^ and is conyerted into
arsenious acid; when more strongly heated, it burns with a pale blue
flame. A piece of arsenic held for a moment bj the tongs in the flame
of a candle, bums for a while with a pale blue flame ; and when this
ceases, the metal continues to waste awaj, producine^ a brownish smoke,
until it is almost entirely consumed. Even arsenic which has been
purified by sublimation in hydrogen ffas, continues to bum away slowly
when set on fire. The arsenious acid appears to be at first accompanied
by suboxide of arsenic, which produces the reddish or brownish white,
garlic-smelling fume, and to be afterwards wholly conrerted into arsenious
acid: for the yapour of pure arsenious acid does not emit the garlic
odour, and metallic arsenic does not yolatilize at the comparatively low
temperature at which the combustion goes on. Hence, if burning arsenic
be thrown into a glass tube, no sublimate of metal is formed. (Mitchell,
SU. Am, J. 19, 122.) IT Schbnbein suggests that the garlic-odour
emitted by arsenic may be due, not to the formation of a suboxide, but
to a peculiar modification of arsenious acid, As^O*, which is subse-
quently conyerted into ordinary arsenious acid, 2AsO'. {Pogg. 75,
377.) % — 2. Arsenic, when covered with water, and exposed to the air
at' ordinary temperatures, is conyerted into arsenious acid. The water
absorbs the oxygen of the air, transfers it to the arsenic, and dissolves
the arsenious acid as it forms. If air be blown into water through which
pounded arsenic is diffused, the liquid, after ten or fifteen minutes, gives
a strone yellow colour with hydrosulphuric acid. (Orfila, J, Chim, Med,
6, 6.) If the arsenic powder is merely moistened with water, it oxidates
still more quickly. This circumstance may perhaps explain the observa-
tion of Boullay {J» Pharm. 13, 433), and of Schwabe {Br, Arch, 11,
262), namely, that pounded arsenic in large quantities, (8 lbs. for ex-
ample) becomes heated by exposure to the air. In the instance mentioned
by Boullay, the heat was so great as to set fire to the arsenic; and when
the combustion was stopped by moistening with water, it broke out again,
after several days, in a quantity of the arsenic which had been sent away
in a packet. According to Biichner {Br, Arch, 19, 258), this rise of tem-
perature takes place only when the arsenic is moistened with water during
pulverization. — 3. Arsenic vapour passed, together with vapour of water,
through a red-hot tube, yields but very little hydrogen gas. Hlegnault,
Ann. Chim, Phys, 62, 364.)— -Pure water boiled with arsenic, aissolves a
small quantity of arsenious acid, while solid arsenide of hydrogen is left
behind, in the form of a brown powder. ^Orfila.) — Arsenic heated, but
not to redness, with hydrate of potash, lorms arsenite of potash and
arsenide of potassium, and liberates hydrogen gas. (Soubeiran.) [For
further development of this matter, vid. Formation of ^r«entcacid, 6,
p. 260.] At ordinary temperatures, and out of contact of air, arsenic
undergoes no alteration when immersed in water freed from air by boil-
ing. (Bonsdorff.) — 4. With boiling oil of vitriol, arsenic forms arsenious
acid and liberates sulphurous acid; with dilute nitric acid, it likewise
forms arsenious aeid and liberates nitric oxide. Strong hydrochloric acid
254 ARSENIC.
boiled with arsenic, neither dissolyes the metal nor gives off hydrogen.
(H. Rose, Gmelin.) BerthoUet maintains the contrary. (^Si^. ehimique,
2, 395.)
Freparation, — By roasting arseniferous minerals in a furnace, from
which the fames are conyeyed into a horizontal condensinff chamber,
called the Paiwm-irap (Gififang), or into a building called the Foisan"
iowvr iJ^fUkuraC)^ containing a number of chambers, placed one aboye
the other. The Foiion-meal, or Anenic-fMcU, (Oiftnuhl, Arser$ikmM,)
which condenses in these chambers, is introduced either alone, or mixed
with a small quantity of crude potash to retain the sulphur, into an iron
pot, on which a number of cylindrical iron rings are luted one above the
other, and heated till it volatilizes. The gre9.ter peart of the aroeaious
acid condenses on the rings at a temperature near its melting point, and
sinters together into a yitreous mass, called whUe anenie-^la99. The
uncondeused portion of the vapour is carried from the uppermost ring
through a tube into a condensing chamber, in which it solidifies in the
form of meal, — The product is purified from any sulphide of aarsenic
accidentally present, by mixing it with a small Quantity of potash, and
subliming it again. Arsenic-glass, e. g., that irom Andreasberg, fre-
quently contains oxide of antimony, a portion only of which can be
separated by sublimation. By digestion in cold hydrochloric acid, the
antimonio oxide is gradually dissolved in preference to the arsenious
acid; hence the resulting solution, when treated with hydrosulphuric
acid, gives first a yellowish red and then a yellow preoipitote. On dis-
solving the precipitate in hot nitric acid, a residue is left, consisting of
antimonic oxide mixed with arsenic acid; this residue dissolves readily in
hydrochloric or tartaric acid, yielding a solution which gives all the
reactions of antimonic oxide. (Wiggers, Ann. Fharm. 41, 347.)
FroperticB. — Arsenious acid occurs in two crystalline forms, and
likewise in the amorphous state.
a. Octohedral Arsenious Acid. — Obtained: 1. In the sublimation
process, when the vapour is so quickly cooled that the acid solidifies at
once, without passing through the semifused state. Arsenic-meal like-
wise belongs to this variety, but it is generally contaminated with
metallic arsenic, sulphide of arsenic, and other impurities. — 2. By the
cooling of a hot saturated aqueous solution. — 3. When white arsenic-
glass is preserved for a long time, under which circumstances it becomes
opaque and acquires a texture like that of porcelain or enamel. — Opaque
Arsenic-glass f when obtained as in (1) or (2), forms regular octohe-
drons and tetrahedrons, which are transparent and have a strong lustre.
Specific gravity of the opaque arsenic-glass, 3-529 (Taylor, Fhil. Mag, J.
9, 482), 3*695 (Guibourt) ; that of arsenious acid obtained by digesting
arsenic in nitric acid and washing with water, is 37202 (Karsten).
6. Hight-rhombie Arsenious Acid. — This variety is, in a very few in-
stances, obtained .by sublimation, and appears to be isomorphous with
native oxide of antimony. In a furnace in which cobalt-ore was roasted,
arsenious acid was found sublimed in transparent, colourless, thin, flexible,
six-sided tables, having a pearly lustre, and a plane of cleavage parallel
to the principal face (with octohedrons attached to them here and there).
These crystals, when sublimed or dissolved in hot water, and left to sepa-
rate by cooling, were converted into octohedrons and tetrahedrons; they
were free from arsenic acid. (Wohler, Fogg. 26, 177.) — IT If a boiling
solution of potash be saturated with arsenious acid and left to cool, the
ARSENIOUS ACID. ^255
arsenious acid gradaally separates from it, and almost always in right
rhombic crystals^ isomorphous with natiye oxide of antimony. (Pasteur,
Campt. rend. 24, 774.) IT
c. Amm*ph(m8 Arsenious Acid. — Newly prepared, transparent arsepic-
glass is in this state. Specific graYity= 3*698, at 4° in vacuo (Le Royer
& Dumas); 37026 (Karsten); 3-7385 (Guibourt); 3-798 (Taylor).
Transparent and colourless glass, with conchoidal fracture. The trans-
parent vitreous acid becomes turbid in a few months at ordinary tem-
peratures, and afterwards white and opaque ; according to Fuchs {Schw,
67, 429), this change takes place in proportion as the acid passes from
the amorphous to the crystalline state. Vitreous arsenious acid becomes
opaque, both in the open air and in close vessels containing air. At 100°,
according to Regnault {Ann. Chim. Phys, 76, 144), the opacity comes on
quickly. On the other hand, the glass remains transparent for years
when kept under water (Christison, Fogg, 36, 494), or under alcohol, or
alone in a vessel from which air is completely excluded (H. Rose, Fogg,
52, 454). Under hydrochloric acid, on the contrary, it becomes opaque.
(Wiggers.) According to Kriiger (Kastn, Arch, 2, 473), the glass becomes
opaque only when in contact with moist air, and the change is accom-
panied by an increase in weight, amounting to j^. When from 1 to 1^
parts of transparent arsenious acid are dissolved by half an hour's boil-
ing, in a mixture of 6 parts of fuming hydrochloric acid and 2 parts of
water, and the solution left to cool as slowly as possible, the arsenious
acid crystallizes in transparent octohedrons, and the formation of each
crystal is accompanied by a spark; on agitation, which gives rise to the
formation of many new cirystals, a corresponding number of sparks is
produced. If from 4 to 6 parts of arsenic-glass are dissolved in the
above-mentioned mixture, the light produced by the crystallization is
sufficient to illuminate a dark room. As long as the deposition of crystals
goes on, so Ion? is li^ht perceived on agitating the liquid; and this
appearance may oe visible on the second, and even, though very faintly,
on the third evening. If the liquid be then boiled, so as to dissolve the
remaining portion of the vitreous acid, crystallization again takes place,
accompanied by emission of light, though not so bright as before. If
the liquid be rapidly cooled, the acid separates in the pulverulent state,
and little or no light is emitted. A solution of arsenious acid in a hot
mixture of hydrochloric and nitric acid, the quantity of the latter not
being sufficient to convert the whole of the arsenious acid into arsenic
acid, likewise emits a strong light as the acid crystallizes. Boiling dilute
sulphuric acid dissolves arsenious acid in smaller quantity, and exhibits
only occasional luminosity. Nitric and acetic acid, which dissolve still
less of the arsenious acia, exhibit no luminosity whatever. Arsenious
acid, which has acquired the porcelain texture, and likewise arsenic meal,
exhibit, when dissolved in hydrochloric acid, a very feeble luminosity on
agitation. (H. Rose, Pogg, 35, 48.)
Arsenious acid, when heated suddenly or under increased pressure,
melts to a glass. The vitreous arsenious acid c may be fused before it
volatilizes to any considerable extent ; the crystallized acid a appears to
have a higher melting point, and evaporates before fusion. (Wbhler, Jnn.
Pharm. 41, 155.) The acid does not volatilize at ordinary temperatures.
(Faraday, Fogg, 19, 501.) It volatilizes more readily than the metal,
at 218°, according to Mitchell. Specific gravity of the valour =13*85.
(Mitscherlich.) The colourless vapour emits no smell of garlic. TScheffer,
Fischer.) It is only when the acid is heated on deoxidizing fiUDstaaceSi
256
AUSENIC.
each as charcoal or iron, that the garlic odour becomes perceptible.—
Arsenioas acid in solution reddens litmus slightly. According to Guibourt,
it is only the solution of the transparent acid prepared hot and then
cooled that reddens litmus; whereas, according to the same authority, the
solution of that which has become opaque turns reddened litmus blue;
Omelin, however, found that the solution of the latter likewise reddened
litmus slightly. The acid has a rough taste, slightly metallic, and after-
wards sweetish. It is one of the most violent among the acrid poisons.
Thonuon. Th^nard. H.Dary. Proost.
Ai 75 .... 7576 .... 70-37 .... 7424 .... 75 .... 75*2
30 24 .... 24-24 .... 29-63 .... 2576 .... 25 .... 24-8
A«0> .... 99 .... 10000 .... 10000 .... 100-00 .... 100 .... 1000
r
'Ifiticherlich. BeneUos. Richter.
Ai 75-73 .... 75-782 .... 86-86
30 24-27 .... 24-218 .... 13'14
100-00 Z. 100-000 Z 100-00
VoL Sp. gr,
Anenic yaponr 1 10*3995
Oxygen gas 3 3*3279
Anenious add Tapour .... 1 13*7274
(Aa*0* a 2 . 47004 + 3 . 100 » 1240*08. BeneUas.)
Decompositions. — An aqueous solution of arsenious acid placed iu the
voltaic circuit, yields oxygen at the positive pole, arseniuretted hydrogen
gas and metallic arsenic at the negative pole; less quickly however than
arsenic acid. (Bischof; comp. Simon, I., 393.)-~2. At a heat short of
redness, hydrogen, carbon, carbonic oxide, phosphorus, sulphur, potas-
sium, sodium, and zinc (the last three with vivid combustion : Oay-Ltutsae
ik TlUnardy Gehlen), and other metals, withdraw all the oxygen from
arsenious acid, forming respectively, water, carbonic acid, phosphoric
acid, sulphurous acid, or a metallic oxide; arsenic reduced by phosphorus
or sulphur enters into combination with a portion of these substances.
If a small quantity of arsenious acid be placed at the bottom of a narrow
glass tube, — a slip of charcoal just over it — and the heat of a spirit-lamp
applied, first to the charcoal and then to the arsenious acid, metallic arsenic
sublimes on the cold part of the tube. If a mixture of arsenious acid
and carbonate of soda be placed upon charcoal and exposed to the inner
blowpipe flame, the garlic odour becomes perceptible. (Berzelius.)**-
3. Aqueous phosphorous or hypophosphorons acid, boiled down with arse-
nious acid till phosphurettea hydrogen begins to escape, reduces the
arsenic. — 4. From the aqueous solution, zinc, cadmium, and tin precipi-
tate the arsenic very slowly ; on the addition of hydrochloric acid, these
same metals reduce the arsenic more quickly ; and under the same cir-
cumstances, the reduction is likewise effected, though more slowly, by anti-
mony, bismuth, lead, and copper. The reduction is never complete ;
zinc throws down brown pulverulent arsenide of hydrogen ; iron does
not reduce the arsenic, but becomes oxidated and forms arsenite of ferric
oxide. (Fischer, Pogg. 9, 260.) When hydrochloric acid is present, how-
ever, the greater part of the arsenic escapes in the form of arseniuretted
hydrogen gas. — 5. Arsenious acid heated with lime is resolved, according
to Wollaston, without evolution of light or beat, into arseniate of lime,
ARSENIOUS ACID. 257
andsnblimed metallio arsenic; according to Gay-Lnssac, a similar reaction
takes place with carbonate of potash. In the former case, arsenite of lime
is formed as well as arseniate, the qaantity being greater as the ignition
is less intense. (Simon.) — 6. Arseniuus acid dissolved in water and mixed
with a stronger acid^ is qaicklj decomposed by sulphuretted hydrogen,
yielding tersulphide of arsenic and water : AsO'+3HS=AsS'+3HO.
Combinations. — a. With Water. — Aqueous Arsenious Acid. — ^Arseni-
ous acid dissolves very slowly in cold water, but more quickly in boiling
water. A hot saturated solution contains 1 part of arsenions acid in 10
or 12 parts of water; on cooling, part of the acid separates in small anhy«
drous crystals, leaving a solution containing 1 part of the acid in 20 or
30 parts of water.
One part of arsenious acid dissolves in 7*72 parts of boiling water, if
it has previously become opaaue, and in 9*33 parts if it is still trans*
parent (Guibourt) ; in 10*5 (Wenzel); in 11-34 (Fischer); in 12 (Klap-
roth) ; m 12*2 (Bucholz) ; in 15 (Brandt, Justi, Bergman) ; in 16 (Rud.
Aug. Vogel); in 21 if the acid is transparent, and in 24, if it is opaque
r Taylor) ; in 24 rLametherie) ; in 40 (Pomer) ; in 64 (Banme) ; in 80
(Navier) ; in 200 (Nasse) ; in 640 (Hagen). — To dissolve 1 part of arseni-
ous acid in 1 2 parts of water, it is necessary to boil an excess of it with
the water; if 1 part of the acid is boiled with only 12 parts of water, a
considerable quantity remains undissolved; even with 1 part of the acid in
50 or 60 parts of water, long continued boiling is necessary to effect com-
plete solution. — If a solution saturated by lonff boiliu£^ with excess of acid
and then poured off from the undissolved portion, be boiled down continu-
ously to one-half of its bulk, the whole of the acid remains dissolved, so that
the concentrated liquid contains 1 part of acid in 6 parts of water. '(Fischer.)
After this solution has been left to stand for aome time at ordinary,
temperatures, 1 part of arsenious acid remains dissolved in 16 parts of
water at 16^ and in 20 parts at 7'' (Bucholz); in 33 (Klaproth); in
38*45 after 3 days, and 55 after 8 days, and in 64*5 after 2 or 3 weeks
at 10"" (Fischer); in 33*52, if the acid had become opaque before it was
dissolved, and in 55*06 if it was transparent at the time of solution
(Guibourt) ; in 38 water after half a year, if it was opaque, and in 53....71
water after 48 hours, if it was transparent (Taylor.)
When pulverized arsenious acid in excess is left to digest for several
days in cold water, 1 part of it dissolves in 50 parts of the water
(Bucholz) ; in 66 (Fischer) ; in 80 (Bergman) ; in 80, if it had become
opaque, in 103 if it was still transparent (Guibourt) ; in 96 at 10° (Spel-
man) ; in 96 at 35"" (Kahnemann) ; in 320 at 20*" (Nasse, Schw. 5, 217) ;
in 400 (Klaproth, Sckw, 6, 231).
If one part of pulverized arsenious acid be digested for 10 days at
19°....25^ in 5.. ..10 parts of water, the resulting solution contains 1 part
of acid in 50 parts of water ; a solution of the same strength is obtained
in 25 days by digesting 1 part of the acid in 40 parts of water. If
1 part of the acid be immersed in 80 parts of water, the resulting solution
contains ^ ; with 160 parts of water, -^ ; with 240 water, -^ ; with
1000 water, xruz * ^°^ ^^^^ when 1 part of acid is digested at ordinary
temperatures for several days with 16,000.... 100,000 parts of water, a
portion still remains undissolved. — Pulverized opaque arsenions acid was
immersed in various proportions of water, and the liquid set aside in
closed bottles and in a cool place. After 18 years, the following results
were obtained : 1 part of arsenious acid in ] 000 parts of water : perfect
solution ; the liquid contained nothing but arsenious acid and arsenic
yoL. ly. B
258 ARSENIC.
acid. — 1 part of arsenions acid in 100 parts of water : 0*017 pt. acid
remained undissolved. — 1 part of acid in 35 'parts of water : the nndis-
solved portion amonnted to 0*35 pt., so that the solution contained 1 part
of acid in 54 of water. (Gm.)
The cause of this rerj slow solution of arsenious acid in cold water is
to be found in the small adhesion and affinity of water for arsenious acid
and the great cohesive force of the latter. Fischer's supposition — ^that
arsenic-glass only dissolves in water in so far as it talces up more oxygen,
and that when cold water is used, the oxidation takes place by unequal
distribution of the oxygen, ao that a grey oxide of arsenic containing leas
oxygen remains undissolved, whereas when the acid is digested in hot
water, it is oxidated by the oxygen of the water, but in such a manner
thai the hydrogen is not set free in the gaseous form, but remains in the
liquid in a state of loose combination — is directly contradicted by experi-
ment : for Bncholx and Pfiiff, as well as Gmelin, found that pure arsenic-
glass is perfectly soluble in cold water ; and aa to oxidation by the oxygen
of the water, in such a manner that the hydrogen is not set free but
remains in the liquid without entering into any other state of combination
i— we can only say that it is a process of which no definite idea can be
formed. (See also Phillips, Ann. Phil, 8, 152.)
IT Bussy finds that the ritreous acid disaolvee more quickly and more
abundantly in water than that which has become opaque ; the same quan-
tity of water which at 12° or 13° will take up 36 or 38 parts of the for-
mer, will not dissolve more than 12 or 14 of the latter. By long boiling
with water, the opaque acid is converted into the transparent variety-*
that is to say, it acquires the solubility of the latter, so that a litre of
the fluid takes up 110 grammes of the acid. On the other hand, by the
. continued action of water and of a low temperature, the vitreous acid is
converted into the opaqu»—that is to say, the solution, after a while,
becomes weaker, retaining only the proportion of acid which corre-
Bponds to the solubility of the opaque variety. Comminution diminishes
the solubility of the opaque and increases that of the vitreous acid.
Arsenious acid which has been rendered opaque by the action of ammonia,
and that which has been crystallised from an aqueous solution, are equally
soluble in water. The anomalies relating to the solubility of arsenious
acid in water may perhaps be due to the simultaneous occurrence of both
modifications of it in the solution. — The solutions of the two varieties
affect litmus in the same manner. — The opaque acid dissolves more slowly
in hydrochloric acid than the vitreous modification. (Compt. rend. 24,
774; Liebig & Kopp's JoAretftmc^, 1847—1848, 422.) IT
The solution of arsenious acid in water is transparent and colourless,
and reddens litmus slightly. Sulphuretted hydrogen water colours it
yellow, and, on the addition of a stronger acid, throws down a yellow
precipitate. It gives a white precipitate with excess of lime-water;
aiskin-green {Sehede^s green) with an ammonia-salt of copper (ammonio-
nitrate or sulphate, for example) ; and on the addition of a small quan-
tity of alkali, a white precipitate with nitrate of roercurous oxide and
corrosive sublimate, and an egg-yellow precipitate with nitrate of silver.
It colours the red solution of permanganate of potash brown-yellow
(after standing for a few days, the mixture becomes decolorized and depo-
sits brown fiakes); turns the yellow colour of chromate of potash to green
(vid. Arsenic and Chromium, p. 312) ; decolorizes the aqueous solution of
iodine or bromine ; produces, when mixed with hydrochloric acid, a grey
metallic d^osit on copper; and evolyes arseniuretted hydrogen gas with
zinc and hydrochloric acid.
ARSENIOUS ACID. 259
The limit of the yellow colouring by hydros alph uric acid is attained
with 1 part of arsenious acid in 10,000 parts of water. (Lassaigne, J.
Chim. filed. 8, 584). — That of the yellow precipitation by hydrosulphuric
acid in presence of hydrochloric acid, with 1 part of arsenious acid in
80,000 of liquid (Lassaigne) j 1 pt. in 90,000 (Keinsch, J,pr. Ckem. 13,
133); 1 pt. m 160,000 (Brandos & Ebeling, Br. Arch. 25, 269.)— Lime-
water does not precipitate a solution of arsenious acid containing less than
1 part of acid in 4000 parts of water (Harting, J. pr. Ckem. 22, 49) ;
according to Lassaigne, the limit is 1 part of acid in 5000 of water. —
The limit of the precipitation by amraonio-sulphate of copper is 1 part of
arsenious acid in 160,500 of water (Lassaigne); 1 in 250,000 (Brandes &
Ebeling) ; the precipitate, however, does not show its characteristic colour
if the proportion of acid is less than 1 in 12,000. (Harting.) — The green
colouring of chromate of potash will indicate the presence of 1 part of
arsenious acid in 1000 parts of water. (Brandos Sc Ebeling.) — The aqueous
solution of arsenious acid mixed with hydrochloric acid quickly produces
a grey metallic deposit on a clean plate of copper. (By a solution of
arsenious acid in strong hydrochloric acid, this deposit is not produced till
after the lapse of several days or even weeks at ordinary temperatures,
but immediately on the application of heat.) On boiling the liquid, the
deposit turns black and peels off in black scales. The grey deposit is
immediately produced on boiling, even in a solution containing only 1
part of arsenious acid in 100,000 parts of water; in a solution containing
1 part in 200,000 the deposit takes half an hour to form; and the limit
of the reaction is about 1 part in 250,000. ...300,000. Aqueous arsenious
acid without hydrochloric acid has no action on copper. (Reinsch, J. pr.
Ckem. 21, 244.)
h. With the stronger acids, arsenious acid forms salts in which it plays
the part of a bane, and which may therefore be called Salts of Arsbmio
Oxide. In some acids, especially in certain mineral acids, arsenious acid
is scarcely soluble excepting on the application of heat, and separates
again almost completely on cooling; hydrochloric acid and certain vege-
table acids retain a considerable quantity of it even in the cold. The
salts of arsenic oxide are precipitated yellow by hydrosulphuric acid, yield
arseniuretted hydrogen and metallic arsenic when treated with zinc, and
deposit metallic arsenic on polished copper.
c. With Salifiable Bases, arsenious acid forms salts called Arsenites.
The affinity between the acid and base in these salts is very slight; hence
they are decomposed by many other acids, even by carbonic acid, and
deposit a white powder. Most arsenites, when heated alone, are decom-
posed; some of them allow the acid to volatilize, while the base remains:
the arsenites of the fixed alkalis, and a few others, give off arsenic and
leave a salt of arsenic acid (5A80'=:3AsO*+2As). Arsenite of silver
gives off arsenious acid, and leaves a mixture of arseniate of silver and
I metallic silver; arsenite of lead alone withstands a red heat without
' decomposition, and arsenite of magnesia is but very imperfectly decom-
' posed. (Simon, Fogg. 40, 435.) When heated with charcoal powder, the
, arsenites give off metallic arsenic; under such circumstances, however,
j — e.g., in the case of copper — a metallic arsenide may be formed. A
i mixture of an arsenite with charcoal powder (especially on the addition
' of borax) or with oxalate of lime, ignited in a bulb blown at the end of a
narrow glass tube, yields a sublimate of metallic arsenic. Arsenites
ignited with carbonate of soda upon charcoal, in the inner blowpipe flamO;
s2
260 ARSENIC.
emit the odonr of garlic. Those arsenites, which are insoluble in water,
dissolve in hydrochloric acid, and seyeral of them also in sulphate, hydro-
chlorate, and nitrate of ammonia. Alkaline arsenites, dissolved in water,
give white precipitates with lime-water and lime-salts; yellowish green
with cupric salts; egg-yellow with nitrate of silver. Hydrosulphuric
acid gives no precipitate unless a stronger acid is likewise present ; but
all arsenites which are not soluble in water, are, when dissolved in hydro-
chloric acid, immediately precipitated by hydrosulphuric acid; and if the
metallic oxide with which the arsenious acid is combined, is likewise pre-
cipitable by hydrosulphuric acid, a compound metallic sulphide may be
produced.
d, Arsenious acid is slightly soluble in alcohoL
C. AussNic Acid. AsO*.
Arsensaure, Arteniksciure, Acide arsenique.
Formation, — 1. The aqueous solutions of chlorine (Bergman), bromine
(Balard), and iodine (Simon, Repert. 65, 198\ convert the metal and
arsenious acid into arsenic acid. The same effect is produced by a mix-
ture of nitric and hydrochloric acid. (Scheele.) If the mixture of hydro-
chloric and nitric acid is too dilute to evolve chlorine, it does not attack
the arsenic till heat is applied, or a few drops of hyponitric acid added.
(Millon.) — 2. Strong nitric acid boiled with the metal or with arsenious
acid, converts it into arsenic acid. (Thomson.) If the quantity of nitric
acid is not sufficient to convert the whole of the arsenic into arsenic acid,
a white powder of arsenious acid is at first produced. Dilute nitric acid,
boiled with arsenic, produces a mixture of arsenious and arsenic acid. (Gm.)
•—3. Arsenic immersed in gaseous hypochlorous acid, or in its aqueous
solution, 3rields arsenic acid, free chlorine, and a small quantity of chloride
of arsenic; arsenious acid in aqueous h3rpochlorous acid, yields arsenic
acid and chlorine gas; arsenic immersed in the aqueous solution of an
alkaline hypochlorite loses its lustre, and forms an arseniate of the alkali.
(Balard.) — 4. When metallic arsenic or arsenious acid, is exploded with
nitre. — 5. When the metal is exploded with chlorate of potash, an effect
which is brought about even by percussion. — 6. When an alkaline
arsenite is ignited, an arseniate of the alkali is formed and metallic
arsenic is volatilized. Also when arsenious acid is heated to redness with
an alkaline carbonate, arsenic acid is formed and combines with the
alkali, while carbonic aci^ is driven off (Gay-Lussac); similarly with lime.
(Wollaston).— When arsenic is heated, but not to redness, with hydrate
of potash, hydrogen is evolved, and arsenite of potash, together with
arsenide of potassium, produced. In consequence of the formation of the
latter compound, the mass when dissolved in water, evolves arseniuretted
hydrogen gas (Gehlen); if it be heated to low redness, it gives off merely
the excess of arsenic; but at a higher temperature, arsenic is given off
from the arsenious acid, and arseniate of potash remains behind. (Soubei-
ran.) Hydrate of soda exerts a similar action, but the brown mass formed
by gentle heating retains a smaller quantity of arsenide of the alkali-
metal, and therefore effervesces less strongly with water. Hydrate of
barjjrta digested with arsenic gives off hydrogen, and forms a brown mass,
which evolves but a small quantity of gas when treated with water, and
contains nothing but arsenite of baryta. Hydrate of lime and hydrate of
magnesia likewise form arsenites only, not a trace of arseniate. Abo
ARSENIC ACID. 261
when arsenic vapour is pajssed over red-hot baryta or lime, a black mixture
of arsenite of baryta or lime with arsenide of bariam or calcium is pro-
duced ; but the decomposition is very imperfect. (Soubeiran.) This state-
ment; that lime does not form a salt with arsenic acid is in opposition to that
of Wollaston above cited; perhaps Wollaston applied a stronger heat than
Soubeiran. — 7. Arsenite of cupric oxide is decomposed by potash, yielding
cuprous oxide and arseniate of potash. ( Vauquelin, J. Flmrm, 9, 230.)
Preparation. — 1 -4 pt. arsenious acid is heated in a retort or in a glass
flask, with 1 part of hydrochloric acid, sp. gr. 1*2, and 12 parts of nitric
acid, sp. gr. 1*25 — the liquid evaporated to dryness — and the residue
heated to commencing redness (Bucholz.) — 2. Thomson dissolves arsenic
in nitric acid, evaporates to dryness, separates the resulting arsenic acid
from the arsenious acid by solution in water, and again evaporates to
dryness.
Properties. — Solid; after fusion, it is colourless, transparent, and glassy;
after long keeping, or if it has been less strongly heated, it is white and
opaque. Specific gravity = 3'391 (Bergman); 3*729 (Herapath); and
3*7342 after gentle ignition (Karsten). — Melts at a low red heat. Red-
dens lime strongly. Almost tasteless at first, but afterwards tastes very
sharp and acid. Excessively poisonons.
As
o»
.«•* 75
.... 40
....
65-22
34*78
Thomson.
later. earlier.
61-29 .... 65-62
.... 38-71 .... 34-38 .. .
Proust. Mitscherlich.
65 .... 65-04
35 .... 34-96
AsO* ...
115
....
As
10000
.... 100-00
BeneUas.
65-283
34-717
.... 100-00 ....
Th^nard.
65-4
34*6
100 .... 100-00
Bachols*
72
.... £o
100000 .... 100-0 .... 100
(As^O* s 2 . 47004 + 5 • 100 = 144008. BerzeUas.)
Decompositions. — The aqueous solution placed in the circuit of the
voltaic battery rapidly deposits arsenic [and evolves arseniuretted hydro-
gen j] at the negative pole, and gives off oxygen at the positive pole.*—
2. The dry acid, when heated somewhat above its melting point, is
resolved into oxygen gas and arsenious acid, which volatilizes. The
arsenic acid which remains undecomposed when the experiment is inter-
rupted, is mixed with a small quantity of arsenious acid, some of which
remains undissolved on digesting the residue in hot water, and the rest
separates as the solution is evaporated (Bucholz, Richter.) — -3. Hydrogen,
carbon, phosphorus, sulphur, potassium, sodium, manganese, antimony,
bismuth, zinc, tin, lead, iron, cobalt, nickel, copper, and likewise arsenic
itself, when heated somewhat strongly with arsenic acid, either abstract
the whole of its oxygen, or convert it into arsenious acid. Mercury and
silver decompose this acid at ver^ high temperatures only; gold and jpla*
tinum not at all. The deoxidatiou is often attended with combustion,
e. ff., when effected by potassium or sodium (Gray-Lussac & Th^nard), or
by iron (Scheele), or by zinc (Berzelius.) — 4. The aqueous acid with zinc,
tin, or iron, yields an arseniate of the corresponding metallic oxide, and
arseniuretted hydrogen. Under these circnmstances, iron precipitates a
small quantity of arsenic in black needles; zinc precipitates it in the form
of a brown powder. (Fischer, Poffff. 9, 261; Mohr, Ann, Pltarm. 23, 219.)
262 ARSENIC.
. The aqueous acid placed under phospbureited hydrogen gaa soon
becomes covered with a dark copper-coloured deposit^ probably consisting
of phosphide of arsenic. (Graham.) — 6. Dry arsenic acid absorbs sulphu-
retted hydrogen, forming water and pentasulphide of arsenic. (A. Yogel.)
When sulphuretted hydrogen is passed through aqueous arsenic acid, the
liquid becomes turbid, sometimes in a few minutes, sometimes not for
hours; the stronger the solution, the sooner does it become turbid; ulti-
mately, the arsenic is completely precipitated in the form of pentasulphide,
but not till the gas has been passed through the solution for a long time.
AsO< + 5HS = AsSfi + 5HO.
If araenious acid is present, the turbidity appears immediately. (Comp,
PfafT; Buchner, Schw. 45, 95, and 119.) — 7. Hyposulphite of soda added
to aqueous arsenic acid precipitates pentasulphide of arsenic, slowly at
ordinary temperatureS| quickly when heat is applied. (Himly^ Ann,
Fkarm. 43, 150.)
6(NaO, S»Oa) + AsO* = 5(NaO, SC) + A«8».
8. Aqueous arsenic acid mixed with sulphurous acid, quickly deposits
large octohedrons of arsenious acid: this reduction la accelerated by heat.
(Wbhler, Ann. PJuirm, 30, 224.)
Combinations, — a. With Water. — a. Crystallized Arsenic Acid, — The
aqueous solution sometimes deposits largo and highly deliquescent
crystals. (Mitscherlich.)
/9. Aqueous Arsenic Acid. — ^Arsenic acid deliquesces slowly in the air;
dissolves slowly in 6 parts of cold water, more quickly in 2 parts of
hot water. On evaporating the solution, a syrupy and ultimately a
turpentine-like substance is obtained, from which small crystals of arsenic
acid are deposited. (Bucholz.) The solution concentrated as much as
possible has, according to A. Vogel {Kastn, Arch, 9, 319), a density of
2'550; it contains only 40'5 parts of water to 100 parts of acid; remains
liquid at — 26^; absorbs moisture from the air, whereby its density is
increased to 1*935. Aqueous arsenic acid is colourless. It is very
slowly precipitated by hydrosulphuric acid, the precipitate being yellow;
the same result is more quickly produced by digestion for an hour with
an alkaline hydrosulphate, and subsequent addition of hydrochloric acid.
With baryta, strontia, or lime-water m excess, it gives a white precipi-
tate; with an ammonio-salt of copper, pale greenish-blue; and with nitrate
of silver, brown-red. With nitrate of mercurous oxide, it gives a yellowish-
white, and with nitrate of mercuric oxide, a yellow precipitate. It does
not change the colour of chromate or permanganate of potash.
h. With Salifiable Bases, arsenic acid forms salts called Arseniates.
The affinity of arsenic acid for bases is much greater than that of arsenious
acid. Arsenic acid, like ordinary phosphoric acid, requires 3 atoms of
base to form a normal salt; moreover, like phosphoric acid, it forms salts
containing 2 and 1 At. base, and having the deficient portion of base
replaced by 1 or 2 At. basic water; modifications analogous to pyro-
phosphoric and metaphosphoric acid, it does not appear to form. The
tri-acid and di-acid arseniates. of the alkalis have an alkaline reaction,
the mono-acid salts of the same bases, an acid reaction. Many arseniates,
especially those which contain one atom of acid, are fusible. Most
arseniates — ^provided their base is not volatile, and not disposed to abstract
oxygen from the arsenic acid — sustain a red heat without decomposition;
ARSENIC ACID. 263
those which contain one atom of acid however, give off a portion of their
acid in the form of oxygen and arsenious acid. When ignited with
charcoal, they either evolve arsenic or form a metallic arsenide. When a
mixture of an arseniate with charcoal and horacic acid is heated to redness
in a bulh blown at the end of a glass tube, a mirror of arsenic sublimes.
When mixed with carbonate of soda and ignited on charcoal in the inner
blowpipe flame, the arseniates emit the odour of garlic. Hydrogen gas
likewise separates metallic arsenic from many arseniates (the zinc and the
soda salt, for example) at a red heat. When the solution of an arseniate
in hydrochloric acid is saturated with sulphuretted hydrogen, it gradually
yields a precipitate of pentasulphide of arsenic, the precipitation being
slower — sometimes going on for hours — as the solution is more dilute.
If the base of the salt is likewise precipitable by sulphuretted hydrogen
from an acid solution, a compound of pentasulphide of arsenic with the
sulphide of the other metal is precipitated. In the case of cadmium, lead,
copper, and certain other metals, the sulphide of arsenic may be dissolved
out from the precipitate by dilute ammonia, and separated after filtration,
by the aaditiou of hydrochloric acid, the other metallic sulphide remaining
undissolved by the ammonia; but if the other sulphide (bisulphide of tin,
for example) is likewise soluble in ammonia, the ammonia dissolves both
sulphides together. An alkaline hydrosulphate, with the subsequent
addition of hydrochloric acid, acts in the same manner as sulphuretted
hydrogen gas. An aqueous solution of an arseniate boiled with hypo-
sulphite of soda deposits pentasulphide of arsenic on the addition of
hydrochloric acid. Potash withdraws from the arseniates of the earthy
alkalis, eartlis, and heavy metallic oxides, the greater part, if not the
whole of the arsenic aci(L Of the arseniates which contain 3 atoms of
base to one of acid, water dissolves only those which contain the more
soluble alkalis; the others are soluble only in excess of arsenic, sulphuric,
hydrochloric, or nitric acid (according to the base), or in ammoniacal
salts, especially in sal-ammoniac. Arseniate of silver however does not
dissolve in ammoniacal salts. The solutions of the alkaline trisarse-
niates and diarseniates give white precipitates with baryta or lime-water,
and with the salts of baryta, strontia, lime, the earths, manganous oxide^
stannous oxide, zinc-oxide, lead-oxide, and ferric oxide; yellowish white
with uranic and mercurous salts; yellow with mercuric salts; rose-coloured
with cobalt-salts; green with nickel-salts; pale greenish-blue with
cupric salts; light brown with platinic salts; and brown-red with silver
salts. These precipitates are, for the most part, soluble in arsenic, sul«
phuric, hydrochloric, and nitric acid, and likewise in ammoniacal salts.
Arseniate of potash gives a precipitate with sulphate of uranic oxide, even
when so far diluted that only 1 part of arsenic acid is contained in 1 0,000
parts of water, and produces a slight turbidity even with 1 part of acid
m 20,000 parts of water : with sulphate of zinc it gives a precipitate in
500 parts of water, and a slight turbidity in 1000 parts; with sulphate
of ferrous oxide, a precipitate in 10,000 parts of water, and a very slight
turbidity in 30,000 parts; with acetate of lead a precipitate after some
time in 15,000 parts of water, and a very slight turbidity in 60,000
parts. (Brandos & Ebeling.) All arseniates dissolved in water or in
nitric acid give with acetate of lead a white precipitate, which when
heated upon charcoal before the blowpipe, fuses and emits the charao^
teristic odour of arsenic.
264 ARSENIC.
Arsenic and Hydrogen.
A. Solid Arsenide of Hydrogen.
1. When a voltaio current is passed through water, and metallic
arsenic is made to form the neeative electrode, the arsenic becomes
covered with solid arsenide of hydrogen. (H. Davy.) In repeating this
oxperiment, Magnus, who however used but a weak battery, obtained
merely a trace of the solid arsenide; and Soubeiran, from the same cause,
obtained none. — 2. When arsenide of potassium or sodium is dissolved in
water, solid arsenide of hydrogen is left behind. (H. Davy; Gay-Lussac
& Th^nard.) Brown powder. Evolves hydrogen when heated, and
bums on being heated in the air. (H. Davy.) Even when it has pre-
viously been heated to 100^ in a current of hydrogen gas, it still gives off
hydrogen when more strongly heated; and the hydrogen thus evolved is
free from arsenic. (Magnus.) From Soubeiran*s experiments it appears
to be a diarsenide of hydrogen : AsH*.
B. Arsbniuretted Hydrogen Gas. AsH'.
Ar$enwaueritoffg<u, Oas hydrog^ne arsenii.
FamuUian. — 1. When arsenide of potassium or sodium is treated with
water, or when arsenide of zinc, tin, or iron is dissolved in dilute sul-
phuric or hydrochloric acid. — 2. When zinc is dissolved in dilute sulphuric
or hydrochloric acid with which arsenious acid is mixed. Under these
mrcumstances, the zinc is oxidized at the expense both of the water and
of the arsenious acid :
6Zn + 3H0 + AsC + 6S0» = 6(ZiiO, S0») + AsH*.
Iron, in place of the zinc, yields no arseniurettod hydrogen, and tin very
little. (L. A. Buchner, Eeperi. 59, 234; Dupasquier, Compt rend, 14,
511.) Zinc immersed in aqueous arsenious acid, without the addition of
another acid, evolves no gas. (Gm.) — 3. When zinc, tin, or iron is dis-
solved in aqueous arsenic acid, or in a mixture of that acid with hydro-
chloric or sulphuric acid. (Scheele.)
8Zn + 3H0 + AiO» + 8S0» (or AsO^) == 8(ZiiO, S0«) or (ZdO, AsO*) + AsH*.
Fischer {Pogg, 9, 261) states that aoueous arsenic acid, if not mixed with
any other oxide, evolves pure hydrogen gas when treated with zinc;
Gmelin, however, obtained arseniuretted hydrogen with perfectly pure
arsenic acid and zinc.
Preparation,'^! . An alloy of antimony with potassium and arsenic is
prepared by i^iting for two hours in a covered crucible, a mixture of 2
parts of sulphide of antimony, 2 parts of cream of tartar, and 1 part of
arsenious acid — and afterwards reducing the product to powder and
exhausting it with water. (Serullas, J. Phys. 98, 136.) The gas thus
obtained contains very little free hydrogen. (Soubeiran.) — 2. Zinc is
fused with an equal weight of arsenic in an earthen retort, and the
pounded alloy dissolved in a mixture of 1 part of oil of vitriol and 3 parts
of water-— or better, in strong hydrochloric acid. (Soubeiran.) This
ARSENIURETTED HYDROGEN. 265
process yields a pnre gas, whereas that obtained from arsenide of tin by
the action of hydrochloric acid — and still more^ that obtained from zinc
and arsenic powder by hydrochloric or sulphuric acid— contains a consi-
derable quantity of free hydrogen. (Soubeiran.) A. Vogel (J. pr. Chem,
6, 345) likewise obtained a perfectly pure gas by dissolying an alloy of
32*1 parts of zinc and 37*6 parts of arsenic in hydrochloric acid.—
3. Zinc mixed with twice its weight of arsenious acid is dissolyed in dilute
sulphuric acid (Proust), or in hydrochloric acid saturated with arsenious
acid, or in hydrochloric or sulphuric acid mixed with arsenic acid.
The gas may be collected oyer water. The most scrupulous care must
be taken that not the smallest quantity be inhaled.
Proper^teff.— Colourless gas. Specific grayity = 2*695. (Dumas.) It
was formerly estimated lower, from admixture of free hydrogen. At
— 40^, the gas condenses to a transparent and colourless liquid, which at
higher temperatures again becomes gaseous. (Stromeyer.) Does not
solidify at —110'' C. or — 166® F. (Faraday.) Has a most repulsiye and
nauseating odour; kiUs small animals instantly, and, eyen when mixed
with air, produces nausea, eructation, giddiness, and oppression. Exces*
siyely poisonous. Qehlen and BuUacke, who accidental! y inhaled this gas,
were seized, partly at once, and partly after a few days, with yiolent
symptoms of poisoning, which, in spite of all remedial measures, terminated
their liyes in nine and twelye days respectiyely. The gas does not redden
litmus.
As 75 96*15
3H 3 3-85
AiH» 78 100-00
Or : Vol. Sp. gr. Vol. Sp. gr.
AnenicTapovr 1 .... 10*3995 = i .... 2*5999
Hydrogen gas 6 .... 0*4160 == 1| .... 0'1040
Anen. Hyd. gas 4 .... 10*8155 == 1 .... 2*7039
Deeompontions, — 1. Eyen the heat of a spirit-lamp is sufficient to
resolye this gas into free hydrogen and metallic arsenic, which settles on
the surface of the yessel. (Gay-Lussac.) One yolume of arseniufetted
hydrogen gas yields 1^ yol. pure hydrogen. (Soubeiran; Comp'. A.* Vogel,
J. pr, ChM. 6, 347.)— -2. The gas, in contact with air or oxygen, may
be set on fire by flame or by the electric spark. With excess of
oxygen it explodes violently, giving out a white flame and forming
water and arsenious acid : i volume of arseniuretted hydrogen consumes
1^ vol. oxygen. (Dumas, Soubeiran.) 4 volumes of arseniuretted hy-
drogen contain 1 vol. arsenic vapour and 6 vols, hydrogen; 1 vol. arsenic
vapour, in forming arsenious acid, takes up 3 vols, ^oxygen, and 6 vols,
hydrogen require 3 vols, oxygen; consequently 4 vols, arseniuretted
hydrogen require 3 -f 3 = 6 vols, oxygen = 1 : IJ. According to Stro-
meyer, 1 volame*of arseniuretted hydrogen consumes 0*613 vols., and,
according to Th^nard 2 vols, oxygen; the former of these statements
is explained by the presence of free hydrogen in the gas. When the
quantity of oxygen is deficient, the hydrogen is first consumed, and
metallic arsenic is deposited on the sides of the vessel. When set on fire in
the air, the gas burns with a bluish-white flame, forming water and
arsenious acid, and, if the air has not free access to it, deposits uncon-
Bumed arsenic as a metallic coating on the surface of the vessel. ' iv
».
266 ARSENIC.
contact with aerated water (Stromeyer), or when mixed with air (Soabei-
ran) the gae, after some time, deposits metallic arsenic. When exposed
to sunlight, the gas, after a few days, deposits a black film over the whole
surface of the containing vessel, whereas if kept in the dark for a week^
it merely deposits a few black flakes; the arsenic, however, is not com-
pletely separated even by the action of the sun for two or three months
in summer. (A. Vogel.) [If the gas were quite free from air, the light
might be supposed to act like a red-heat; but if air were present, it is
more probable that light would favour the oxidation of the gas : in the
fonner case^ the gas would increase in volume; in the latter, it would
diminish.] In contact with anhydrous sulphuric acid, arseniuretted
hydrogen liberates sulphurous acid, and deposits arsenic, which is subse-
quently converted into arsenic [arsenious?] acid. (Aim6, J. Pharm, 21,
87.) Oil of vitriol likewise decomposes the gas at ordinary temperatures,
brown flakes being deposited, which are dissolved on gently heating the
liquid. Oil of vitriol mixed with one part of water acts with difficulty,
and when diluted with 3 parts of water, not at all. (Soubeiran.) —
5. When arseniuretted hydrogen is made to flow into hypochlorous acid
gas, it bums with a blue flame, forming arsenic and hydrochloric acid;
and if the arseniuretted acid is not in excess, chlorine is set free. (Balard.)
— ^. Hyponitric and nitric acid instantly decompose arseniuretted hydro-
gen, oxidating the hydrogen and separating the arsenic, which also is
afterwards oxidized. Fuming nitric acid produces explosion and flame,
(Stromeyer.) If the pure gas be passed into a receiver filled with nitric
acid, it disappears entirely, covering the sides of the vessel with a brown
film. (Soubeiran.) According to Simon {Fogg. 41, 563), strong nitric
acid has no action on the gas.
7. When chlorine is mixed with arseniuretted hydrogen, combustion
ensues, the chlorine taking up the hydrogen and separating the arsenic,
which, if the chlorine is in excess, is inverted into chloride of arsenic,
and, if water is likewise present, into arscnious and arsenic acid.
(Stromeyer, Berzelius, Soubeiran.) Each bubble of chlorine, as it enters
the arseniuretted hydrogen, produces a flame, and forms hydrochloric
acid and a brown cloud of arsenic. (Berzelius.) From a mixture of
1 volume of arseniuretted hydrogen and 50 volumes of air or hydrogen
ffas, a single bubble of chlorme likewise separates arsenic, which is then
deposited on the surface of the containing vessel. (A. Vogel.) If the
arseniuretted hydrogen is mixed with a large quantity of carbonic acid
gas, it is decomposed by chlorine without inflammation, and the sepa-
rated arsenic is likewise found to be free from hydrogen. (Soubeiran.)
From a mixture of arseniuretted and sulphuretted hydrogen, chlorine
precipitates sulphide of arsenic. (Stromeyer.) — ^Chlorine- water introduced
into arseniuretted hydrogen forms hyarochloric acid and arsenious or
arsenic acid. — 8. An aqueous solution of bromine through which the gas
is passed, retains all the arsenic in the form of arsenious acid, and at the
same time forms hydrobromic acid. (Simon.) — 9. Iodine decomposes the
gas slowly at ordinary temperatures, and quickly on the application of
heat, the products being hvdriodic acid and iodide of arsenic; water
forms with the mixture a colourless liquid, containing the same products.
(Soubeiran.) On passing the gas through an alcoholic solution of iodine,
the liquid is decolorized, and only a part of the arsenic is retained in the
form of arsenious acid; if the stream of gas be kept up, a small quantity
of black precipitate is likewise formed. (Simon.) — 10. Sulphur heated
in the gas forms hydrosulphuric acid^ and gives rise to the sublimation,
ARSENIURETTED HYDROGEN. $67
first of arsenic and then of sulphide of arsenic. (Gay-Lossao <& Th^nard^
Soubeiran.) — 11. Phosphorus heated in the gas till it volatilizes, pro-
daces transparent drops of phosphide of arsenic which solidify on
cooling, and non-spontaneously inflammable phosphuretted hydrogen gas.
— 12. Heated potassium or tin (Gay-Lussac & Thenard), or zinc, (I)umas),
withdraws all the arsenic from the gas, leaving pure hydrogen, the
volume of which is -{- of that of the arseniuretted hydrogen. From
1 volume of arseniuretted hydrogen, Gay-Lussac & Th§nard obtained
1*37....! '55 vol. hydrogen, and Dumas 1*48. Since arseniuretted hydrogen
is decomposed by the application of heat alone, and in the decomposition
effected by tin, for example, part of the arsenic is separated in the
free state, it does not appear that the presence of the metal is essential
to the decomposition. (Soubeiran.) — 13. Heated potash- or soda-hydrate
quickly decomposes the gsa, forming arsenite of potash, which, when
more strongly heated, is converted into arseniate of potash mixed with
arsenide of potassium : in this reaction, not only is the hydrogen of the
arseniuretted hydrogen set free, but likewise that of the water, the oxygen
of which combines with the arsenic to form arsenious acid. (Soubeiran.)
The aqueous solution of potash or soda has no action on the gas. —
14. Anhydrous baryta, heated in the gas, liberates the hydrogen, and is
itself converted into a brownish-black mixture of arsenite of baryta and
arsenide of barium. (Soubeiran.) Heated lime produces no other effect
than that of heat alone. (Soubeiran.) — 15. The solutions of many heavy
metallic salts decompose the gas, forming water and a metallic arsenide ;
e. g,, sulphate of copper. (Soubeiran.)
3(CuO, SOS) + AsH> = Cu'As + 3H0 + 3S0».
The blue-vitriol solution absorbs all the arseniuretted hydrogen, and
leaves any pure hydrogen that may be mixed with it unaltered. (Dumas.)
The condensation is very slow. (Simon.) Anhydrous sulphate of copper
suffers the same decomposition ; dry chloride of copper likewise yields
tri-arsenide of copper and hydrochloric acid. (Kane, Fogg, 44, 471.)—
The salts of manganese, zinc, and tin are very slowly decomposed by
arseniuretted hydrofifen; solution of bichloride of tin gives a yellowish
brown precipitate. (Soubeiran.) — 16. Diy protochloride or dichloride of
mercury, with arseniuretted hydrogen gas, forms solid arsenide of hydrogen
and variable quantities of hydrochloric acid gas. (Dumas.) [What
becomes of the mercury ?] With the aqueous solution of protochloride
of mercury, the gas forms a brownish yellow precipitate, containing
1 atom of As., 6 of Hg. and 3 of CI. (H. Rose, Pogg. 51, 423.)
6HgCl + AaH» = 3Hg»a,A» + 3Ha. (rid. Mercury.)
1 7. From the salts of silver, gold, platinum, and rhodium, arseniuretted
hydrogen precipitates the metals, while arsenious acid remains in solu-
tion. (Soubeiran.) e, g,, in the case of nitrate of silver : —
6(AgO, N0») + AaH» = 6Ag + AsO* + 3HO + 6N0».
Nitrate of silver decomposes the gas completely, and with great facility.
(Simon.) The precipitated silver contains a trace of arsenic. When
arseniuretted hydrogen is passed through acetate of silver, the bubbles
as they rise form black flakes of silver and yellow circles of arsenite of
silver, which, if the stream of gas be continued, is likewise decomposed.
(Lassaigne, J, Ckim, med. 16, 685.) — Bichloride of platinum withdraws
all the arsenic from the gas^ and quickly forms a black precipitate^ con-
^68 ARSENIC.
sUting of arsenic and platinum. (Simon.) — Arseuiaretied hydrogen does
not precipate the salts of the alkalis^ or of the earths^ or of the oxides of
iron (Sonbeiran); neither does it precipitate tartar-emetic or sugar of
lead. (Simon.)
Combinations, — Water absorbs one-fifth of its Tolume of arseniuretted
hjdrogen, and thereby acquires the property of forming dark-coloured
precipitates with the above-mentioned metallic salts. (Soubeiran.) — The
gas is not perceptibly absorbed by aqueous alkalis, or by alcohol or ether;
but it is rapidly absorbed by oil of turpentine, and slightly by fixed oils.
On the formation and decomposition of arseniuretted hydrogen gas,
is based the excellent process for detecting arsenic devised by Marsh.
(i\r. Ed. Phil. J. 1826, 229; abo RepeH. 59, 220; Phil Mag. J. 15,
282; 18, 441.) For the application of this process, the arsenic in the
suspected substance must be in the state of arsenious or arsenic acid, or
if not, it must be brought into one of those forms; it is also necessary to
remove wholly or partially any organic matter that may be mixed with
it, as such matter might intenere with the chemical action and produce
frothing. This end is best attained by evaporating to dryness, and
deflagrating the dried mass with nitre; then heating the residue with sul-
phuric acid and water, till all the nitric and nitrous acids are driven off;
nearly saturating with potash ; and decanting the solution from the crystals
of sulphate of potash thereby produced;— or by deflagrating the dried
residue with a mixture of 12 parts of chlorate of potash and 1 part of
hydrate of potash, then dissolving in water and saturating with sulphuric
acid ; — or by heating the mass of animal matter with oil of vitriol or
strong nitric acid till it begins to char, and then exhausting with water ;
or by passing chlorine in excess through water in which the whole mass
is finely diffused, or through the strained decoction obtained by boiling
the organic matter in water containing hydrochloric or sulphuric acid, in
case the arsenic should be contained in the suspected matter, in the form
of arsenious or arsenic acid ;— or by digesting the whole with chloride of
lime and hydrochloric acid, or with chlorate of potash and hydrochloric
acid, and afterwards filtering and boiling.
IT For the separation of the last portions of organic matter, which,
if allowed to remain, are apt to proauce frothing, Wohler recommends
the following process. The greater part of the organic matter having
been removed by either of the methods just cited, and any excess of
chlorine that may be present driven off by boiling, the arsenic is to be
precipitated by passing a stream of sulphuretted hydrogen through the
liquid for a day, then closing the vessel, and leaving the whole to stand
for 24 hours. The precipitate, containing sulphide of arsenic with a
little organic matter, is then to be collected on a small filter, and
thoroughly washed: the filter, with the precipitate, introduced into a
capacious porcelain crucible, and digested with strong nitric acid, tiU the
whole is reduced to a homogeneous mass and dissolved. The excess of
nitric acid is then saturated by the gradual addition of carbonate of
soda; the liquid carefully evaporated to dryness; and the crucible
strondy heated over a lamp till the nitrate of soda is completely fused,
and the whole mass converted into a clear colourless liquid. When this
point is attained, the whole of the organic matter is destroyed. The
crucible is then left to cool, and the saline mass gently heated with pure
concentrated sulphuric acid till the whole of the nitric and nitrous acid
is driven off. The residue is then dissolved in the smallest possible
ARSENIURETTBD HYDROGEN. 269
qnantity of water^ and the solDtion treated in the manner about to be
described. For the complete destruction of the organic matter, a con-
siderable excess of nitrate of soda is required, a condition which maj be
fulfilled by using a large quantity of strong nitric acid to dissolve the
sulphide of arsenic. The nitric acid and carbonate of soda must be quite
free from chlorine; otherwise yolatile chloride of arsenic will be formed,
and occasion loss by escaping. (Wbhler, Ann. Pharm. C9, 367.) IT
The liquid obtained by either of these methods — which contains in
solution either arsenious or arsenic acid, and must be free from nitric
and nitrous acid— is introduced, together with zinc (free from arsenic), and
dilute sulphuric or hydrochloric acid (likewise free from arsenic), into
a peculiar apparatus, for the purpose of developing the arseniuretted
hydrogen. Tne apparatus may be formed of a small two-mouthed
Woulfe*s bottle, one aperture being fitted with an S-tube for pouring in
the liquids, the other with a tube bent at right angles, for the gas to
escape from. This tube may have a bulb blown on its horizontal arm,
for the purpose of retaining any liquid that may be carried over with the
gas, or it may be connected with a horizontal tube containing cotton or
asbestos. The zinc and the dilute sulphuric or hydrochloric acid are
first put into the apparatus, and after the air has been completely ex-
pelled, the operator satisfies himself that the evolved gas neither yields
arsenic spots when burnt {yid. inf.), nor deposits a ring of arsenic when
parsed through a red-hot tube. This point having been satisfactorily
ascertained, the liquid suspected to contain arsenic is poured through the
S-tube, and the gas which afterwards comes off is examined for arsenic.
(Frothing of the liquid arising from organic matter not quite removed,
may be prevented by pouring in a small quantity of oil.)
The trial may be made in either of the following ways: 1. Marshes
original process. The gas is set on fire as it issues idto the air through a
glass tube drawn out to a fine point : it burns with a blue flame and depo.
sits on a piece of glass or porcelain held close to the orifice of the jet, a
brown or steel-grey spot, the ArseniO'Spot. Mere traces of arsenic yield
a great number of spots. Similar spots may however be produced in the
absence of arsenic — either brown-yellow spots arising from organic mat-
ter, in case the mixture has not been properly carbonized by treatment
with nitric or sulphuric acid,— or metallic spots arising from the presence
of antimony. Arsenic-spots dissolye in hot nitric acid, — and if the result*
ing solution be evaporated to dryness and the residue dissolved in water,
the liquid will give the characteristic brown red precipitate with nitrate
of silver. According to Bischoff, arsenic spots are soluble in chloride of
sodium; antimony spots, insoluble. The following modes of distinction
may likewise be applied :
IT a. Arsenic-spots exposed for ten minutes at temperatures between
12® and 15*^ to the action of iodine vapour, assume a pale brownish yellow
colour, which however changes to lemon-yellow after a few minutes*
exposure to the air. If afterwards exposea to the air for a longer time,
they disappear, more quickly however when gently heated. Antimony
spots, similarly treated, become dark brown, then orange-coloured by expo-
sure to the air, and do not subsequently disappear. If the yellow spots
have disappeared by exposure to moist air, they immediately reappear in
the same places with a pale lemon-yellow colour on pouring a saturated
solution of hydrosulphuric acid into the dish on which they are formed, —
inasmuch as the arsenious acid produced by the action ox the air on the
iodide of arsenic, is conyerted by the hydrosulphuric acid into sulphide of
i
270 ARSENIC.
arsenic. On toncbing tHe ycUow spots with ammonia, tliej instantly
disappear again. The spots of iodide of antimony^ on the contrary, do
not disappear when exposed to the air; hydrosulphuric acid converts
them'into orange-colonred sulphide of antimony, and when thos converted,
they resist for a long time the action of dilute ammonia. An alcoholic
solution of iodine immediately dissolves the arsenic spots, and, when sub-
sequently allowed to evaporate spontaneously, leaves a lemon-yellow spot.
Antimony spots are not altered by this solution; but on leaving it to eva-
porate in the air, the black spot of metallic antimony is converted into
orange-coloured iodide of antimony. This iodide withstands a heat of
30° or 40**, and is but little altered by exposure to the air even for several
days. Hydriodic acid containing free iodine may be advantageously used
instead of the alcoholic solution. (Lassaigne, Compt. rend, 21, 1324.)
p. If a few small pieces of phosphorus be laid separate from one ano-
ther in a capsule, and the capsule covered over with another on which
spots have been formed by Marsh's apparatus, these spots disappear in
four or fiye hours if they consist wholly of arsenic, whereas antimony
spots similarly treated remain unaltered for a fortnight ; ultimately, how-
ever, the antimony spots likewise disappear. (Cotteran, Ann. Pharm. 64,
420.) H
2. Berzelius and Liebig pass the gas through a long tube drawn out
to a point and having its middle part heated to redness by a spirit-lamp
or a charcoal fire. The arsenic, as it separates, is deposited towards tbe
contracted part of the tube in the form of an arsenical mirror, which may
afterwards be further examined. When the process is ended, the narrow
neck may be sealed, and, after the tube has become filled with air, the
deposited arsenic may be heated till it oxidizes and forms a white crys-
talline sublimate of arsenious acid; water may then be introduced into
the tube and boiled till it dissolves the arsenious acid, and the resulting
solution tested by the usual reagents.
If antimoniuretted hydrogen should be evolved together with the
arson iuretted hydrogen, the antimony is deposited nearer to the hot part
of the tube — ^generally indeed before the gas reaches the hot part — ^while
the arsenic, being more volatile, is deposited farther off, towards the
point of the tube. The antimony mirror is whiter than that formed
by arsenic. If the tube be sealeci at one end and heated after air has
entered, the antimony mirror yields antimonic oxide; and this, when
boiled with water, forms a solution which does not exhibit the character-
istic reactions of arsenious acid. On passing hydrosulphuric acid gas
through the tube in which, when heated to redness, arsenic and antimony
have been deposited together, and, applying heat, yellow sulphide of
arsenic and red and grey sulphide of antimony are formed; the former of
which is more volatile than the latter (M. Pettenkofer) ; and if hydro-
chloric acid gas be then passed through, the sulphide of antimony is con-
verted into chloride of antimony, which volatilizes, while the sulphide of
arsenic remains unaltered, and may be distinguished from free sulphur by
its solubility in cold ammonia. (Fresenius.) — IT If the metallic mirror
obtained as above be heated a second time while a stream of hydrogen is
passed through the tube, the gas which escapes will have a strong garlic
odour if the mirror contains arsenic ; but none whatever if it consists
wholly of antimony. Moreover, if the part of the tube at which the
mirror is situated be heated to redness by the flame of a spirit-lamp, the
mirror, when subsequently examined by a lens, will be found fused at the
edges, and even separated into distinct shining globules, if it consists of
AKSENIC AND SULPHUR. 271
antimonj — wliereas an arsenic mirror will present no snoh appearance,
since arsenic volatilizes without fusing. (W5hler^ Ann. Pharm, 69,
368.) IT
3. Danger &: Flandin allow the burning gas to issue from the point of
the tube into a long wide tube containing air, in whicb the arsenic con-
denses in the form of arsenious acid ; instead of the tube, a funnel may
also be used, or the neck of a retort separated from the body.
4. Lassaigne passes the arseniuretted hydrogen gas through a solution
of nitrate of silrer ; precipitates the excess of silver by a small quantity
of hydrochloric acid; filters; evaporates to dryness, during which pro-
cess the liberated nitric acid converts the arsenious into arsenic acid; and
tests the latter by the usual reagents.
5. Berzelius passes the gas through a weighed tube heated to redness,
and containing finely-divid^ copper reduced from the oxide by hydrogen.
The copper turns white at the end near the generating vessel, and its
increase in weight gives the quantity of arsenic.
Arsenic and Phosphorus.
A. Prosphibb of Arsekic. — ^A mixture of equal parts of arsenic and
phosphorus placed in a flask and heated in the sand-bath to low redness
yields a brownish black sublimate, which exhibits a conchoidal black
metallic fractnre — ^is permanent in the air — and, when heated in the air,
bums at first with a slight phosphorus flame, and then forms arsenious
acid. (Landgrebe^ Sckw, 60, 184.) — Pelletier, by melting together pbos-
pborus and arsenic, or by boiling phosphorus under water with metallic
arsenic or arsenious acid, obtained a black shining mass, which oxidated
in the air. Landgrebe regards the substance thus formed as a mere
mixture.
B. Phosphate of Arsenious Acid. — Aqueous phosphoric acid dis-
solves arsenious acid, and unites with it, forming crystalline grains.— -The
two acids may be fused together into a glass.
ARSBinc AND Sulphur.
A. One^Hxth Sulphide of Arsenic? — ^Deposited in the form of a
brown powder when bisulphide or tersulphide of arsenic is boiled in soln-
tion of potash; if the potash-ley is strong, the precipitation does not
take place till water is added. The powder contains, besides moisture,
96*46 per cent, of arsenic, and 3*54 p. c. sulphur. It takes fire below
100^, and bums without flame, yielding a yellow powder of sulphide of
arsenic and a crystalline sublimate of arsenious acid. When heated in
vacuo, it forms two sublimates ; the lower of these is metallic arsenic ; the
upper, which amounts to about one-third of the whole, is easily fusible,
translucent, and when in thin pieces exhibits a yellowish brown colour
by transmitted light; black-brown by reflected light. Contains 8d'5
(2 At.1) arsenic, and 10*5 (1 At. 9) sulphur. (Benelius.)
B. Bisulphide op Arsenic; Htpo- arsenious Sulpridb; Htposul-
FH ARSENIOUS AciD.-^Bed Sulphide ofAreenie, Realgar, Sandaraeh, JRuby
ilr«enic.— 'Found native.— Prepared on the large scale by distilling iron
272 ARSENia
pyrites witli arsenical pyrites. — According to Thenard, it may be obtained
by fusing arsenic with the yellow sulphide of arsenic. Crystalline system
of the native variety, the oblique prismatic; Fig. 91 and 99, together
with /*-, «!-, and other faces; i\ the edges between u and tt'=86*';
u : tt-=74^ 30'. Cleavage imperfect, parallel to t, i£, and t. Specific
gravity, 3*5444. (Karsten.) Colour, aurora-red, inclining to hyacinth-
red and brown ; often translucent ; yields an orange-yellow powder, which
becomes red-brown whenever it is heated. Easily fusible, rather more
easily than orpiment; according to Magnus, it ciystallizes on cooling.
When heated out of contact of air, it volatilizes undecomposed at a tem-
perature much below a red heat.
Klaproth. Laugier. Th^nard.
native. native.
Kb 75 .... 70-09 69 .... 69-57 .... 75
2S 32 .... 29-91 31 .... 30*43 .... 23
AsS» 107 .... 100-00 100 .... 100-00 .... 100
Bums in the air with a blue flame, forming sulphurous and arsenious
acid. With hot nitric acid it yields arsenic acid and sulphur, the latter,
by further action of the nitric acid, being converted into sulphuric acid.
With heated oil of vitriol, it forms sulphurous and arsenious acid.
Deflagrates with nitre, producing a vivid light. The Indian White-Jire
is produced by the combustion of a mixture of 24 parts of nitre with 7
sulphur and 2 realgar. When passed together with vapour of water
through a red-hot tube, realgar yields a large quantity of hydrosulphuric
acid gas, and a sublimate of sulphide of arsenic and arsenious acid.
(Regnault, Ann. Chim. Phy9. 62, 384.) When boiled with aqueous
solution of potash or hydrosulphate of potash, it is decomposed, yielding
■^-sulphide of arsenic and sulpharseniate of potassium which dissolves.
(Berzelius.) If the bisulphide of arsenic be dissolved in the alkaline
liquid when cold, the ^-sulphide is not precipitated till the solution is
boiled. ^Berzelius.)
Bisulphide of arsenic combines with basic metallic sulphides forming
a class of sulphur-salts, called by Berzelius, Hyposulpharsenites. They
contain 1, 2, or 3 atoms of a basic metallic sulphide united with 1 atom
of AsS«; e.g. KS, AsS', 2KS, AsS*, and 3KS,AsS*.— Preparation.— 1. By
fusing realgar with another metallic sulphide. — 2. By fusing arsenic with
a compound formed of tersulphide of arsenic and another metallic sul-
phide. When prepared by either of these two methods, the compound
may take up an excess of sulphide of arsenic, and thereby loses its solu-
bility in water. — 3. When orpiment is boiled in a moderately concentrated
solution of carbonate of potash or soda, and the colourless liquid filtered
hot and then left to cool, a brown, flocculent precipitate is obtained, con-
sisting of 1 At. bisulphide of arsenic with 2 At. nionosulphide of potas-
sium or sodium. — 4. The same flakes are obtained by the spontaneous
evaporation of the compounds of tersulphide of arsenic with sulphides of
the alkali-metals and magnesium. — 5. By precipitating the salts of the
earthy alkalis, earths, and heavy metallic oxides, with a cold aqueous
solution of the potassium compound. Yttrium, glucinum, and aluminum,
however, do not appear to form compounds of this kind; for the red
mixtures give off hydrosulphuric acid and yield light-coloured precipitates.
Many heavy metals also— -not manganese and zinc, however, — likewise give
yellow precipitates, which cannot be distinguished from those which are
formed by sulpharsenite of potassium. (Berzelius.)
SULPHAKSENIOUS ACID. 273
The Iiyposalpharseuites are either red or dark brown.
Hyposalpharseniie of potassiam or sodium prepared by (1) or (2) is
resolved bj [hot?] water into black-brown -^alphide of arsenic which is
precipitated, and snlpharseniate of potassium or sodium which dissolves.
Hence, these hyposulpharsenites of the alkali-snlphides cannot be pre-
pared by treating bisulphide of arsenic with the aqueous solution of a
pure alkali or an alkaline hjdrosulphate, because the same decomposition
would ensue. Hence also, metallic arsenic is not dissolved by aqueous
solutions of the alkaline sulpharsenites. The compounds of bisulphide of
arsenic with 2 atoms of potassium-sulphide or sodium^ulphide are resolved
in water into a soluble compound containing excess of potassium- or
sodiumnsnlphide, and an insoluble compound of 1 At. bisulphide of
arsenic with 1 At. sulphide of the alkali-metal. Most other hyposnlph-
arsenites are insoluble in water. Aqueous acids separate bisulphide of
arsenic from many of them, and liberate hydrosulphuric acid. (Berzelius.)
C. Tersulphide of Arsenic; Arsbnioits Sulphide (Berzelius);
SuLPBARSENious AciD. (Giaham.) — Yellow Sulphide of ArseniCf Orpir
fnent, Auripiffment, OpennerU, EetigaUum, Hattsdigelh. Found in nature.
Formed hj the mutual action of arsenious acid and sulphuretted hydrogen
in a liquid containing a strong acid. (Sch. 43.) May be obtained, ac-
cording to Th^nard, by fusing red sulphide of arsenic with sulphur. The
much more poisonous substance obtained on the large scale by subliming
arsenious acid with a small quantity of sulphur, is a mixture of 6 per cent,
of sulphide of arsenic with 94 of arsenious acid : the latter compound may
be extracted hj boiling water. (Guibourt.) The native sulphide forms
crystals belonging to the right prismatic system. Fig. 63; u : u' =:
117^ 5'; easily split, parallel to t, into thin flexible laminse. Specific
gravity = 3'459 (Karsten), 8*48 (Mohs). Of pearly lustre; translucent;
lemon-yellow inclining to orange-yellow. The powder of the native
sulphide is lemon-yellow; that of the artificial variety has an orange-
yellow colour, and turns brown-red whenever it is heated. Fuses easily,
and, if access of air be prevented, volatilizes nndecomposed; the boiling
point, according to Mitscherlich, is about 700^.
BeneUvf. Ltngicr.
Klaproth.
artif, natioe.
natioe.
Af
75
• •••
60*98
61 .... 61-86
..«• 62
3S
48
•«•■
39*02
39 .... 38-14
.... Oo
AbSt ,„,„
123
••«•
100-00
100 .... 100-00
.... 100
Exhibits the same decompositions as B. Red-hot iron or silver with-
draws the sulphur from the vapour and sets the arsenic free, or, if present
in excess, immediately combines with it and forms arsenide of iron or of
silver. A few drops of hot nitric acid placed upon melted orpiment
produce deflagration (Proust); oil of vitriol acts upon it more strongly
than upon realgar. Tersulphide of arsenic deliquesces rapidly in chlorine
gas, evolving great heat and forming chlorosulphide of arsenic (H. Rose.)
When boiled with water, it evolves an extremely small quantity of
hydrosulphuric acid, while a trace of arsenious acid dissolves in the
water. At ordinary temperatures, this action goes on for several days, but
is accelerated by sulphuric or hydrochloric acid. (Decourdemanche, «/*•
CAm. med, 3, 229.) Even the native sulphide undergoes this decomposi-
tion in water, but ihe change is never more than saperficial. (Hiinefeldj
TOL. rv. T
274 AB8SKIC.
J, pr. Chem, 7, 235). When boiled with alroiig hjdroeUorio aeid, H is
deoomiMwed^ but with great difficulty; tbe hydrosttlpbaric acid and
obloride of arsenic wbiob are erelvedy reproduce sulphide of arsenic in
tbe receiver. (Gm.) With aqaeous alkalis it forms solutions containing
arsenite of tbe alkali and sulpnarsenite of tbe metallic sulphide; and on
boiling these solutiona, a small quantity of sulpbarseniate of the metallic
sulphide is formed and -J-^iulphide of arsenic deposited. The vapour of
arsenious sulphide passed over red-hot lime yields sublimed arsenic and
sulphide of calcium^ mixed with a small quantity of sulphate of lime and a
large quantity of arsenite of lime> which, on the application of a stronger
beat, IS converted into arseniate. Red-hot magnesia shows little or no
acti(Mi. (Simon^ JPogg, 40, 411, 437.) When the vapour of arsenious
sulphide is passed over an ignited mixture of charcoal and carbonate of
potash, or charcoal and lime, the charcoal withdraws oxygen from the
alkali — the alkali-metal separates sulphur from part of the arsenious
sulphide— -and the sulphide of the alkali-metal thereby produced combines
with the rest of the arsenious sulphide. (Liebig.) Similar results are
obtained by passing hydrogen over a red-hot mixture of alkaline carbonate
and arsenious sulphide. (Berielius.) The mixture is heated in a tube
drawn out to a fine pointy while a current of hydrogen is passed over
it» The arsenic sublimes in the contracted part (Berxelius.) When
arsenious sulphide is heated with cyanide of potassium, sulphocyanide of
potassium is formed and the whole of the arsenic sublimed. To separate
the arsenic, 1 part of arsenious sulphide is added to 12 parts of a mixture
of 1 part of cyanide of potassium and 3 parts of dry carbonate of soda^
and the whole heated to redness in a glass tube drawn out to a fine point,
dried carbonic acid gas being passed (J^ough the tube during the ignition
(if hydrogen were substituted for the carbonic aoid, antimony, if present,
might sublime together with the arsenic: Freaenitu A Baho,) [For the
behaviour of this compound when heated with litharge, vid, Berthier]
{Ann. Chim. Phy$. 39, 260.) Pulverized arsenious sulphide thrown into
an aqueous solution of protochloride of mercury, quickly produces a white
powder consisting of mchloride of mercury [or a compound of chloride
and sulphide of mercury] and a aolntion oi arsenious aoid and hydro*
chloric acid. ^Pagenstecher, Eepert, 61, 31; 73, 14.) Arsenious sulphide
when distilled, first yields a sulphide of arsenic richer in sulphur than
itself, and afterwards another sulphide richer in arsenic. (Berzelius.)
Combinations, — a. With Water. — Aqueous Tersulphide of Arsenic.
May likewise be reigarded as HydrosulphaU ofArsenioits Acid ^ AsO',
3HS. — Finely divided arsenious sulphide — ^that namely which is obtained
by precipitating arsenious acid with sulphuretted hydrogen — after it has
been washed with cold water, dissolves to a slight extent in hot water,
forming a yeUow solution; water containing sulphuretted hydrogen does
not dissolve it (Berielius. >— 2. Dilute arsenious acid into which hydro-
sulphuric gas is passed, or to which hydrosnlphurlc acid water is added,
forms a dear yellow mixture, but gives no precipitate. It is only when
bydrosulphunc acid gas is passed ihrouffh a saturated aqueous solution of
arsenioua acid that a precipitote is immediately formed. (Bischof, Br. Arch.
17, 239.) The precipitation is almost complete. (Gm.). The arsenious
sulphide separates from the yellow liquid in yellow flakes: (1.) When
the liquid freeies. (Pfaff.)^2. When it is heated (Boutigny): in this
case the precipitaaon is not complete. (Gm.)--3. On the addition of a
Mnall quantity of ,one of the stronger acids. The greatest effect is piro-.
J
SULPHABSSmTES. 276
daodd bj sulpkuric, hydrochioric^ or Biiric aoid; then fallows oxalic aoidj
then acetic, then tartaric acid; carbonic acid likewise appeara to produce
some effect. (Boutignj.) — 4. On the addition of certain salts, f. g. sal-
ammoniac, nitre, sulphate of soda, and sulphate of magnesia. (Boutigny,
•/. Ckinu med. 8, 449.) The aqueous mixture of anenious acid and
hjdrosulphttrio acid when kept for weeks in a stoppered bottle deposite
but little arsenious sulphide. (Gm.) Y According to H. Becker (Fogg.
74, 303) arsenic, whether in the state of arsenious or arsenic aeid, can
never be completely precipitated from its solutions, either by h^drosul-
phuric acid or by alkaline hydrosulphates. The quantity of arsenic which
remains in the li(]^nid may however be rendered utterly insignifioant
(excepting for judicial investigations) by adopting the precaution : (I) of
placing the liquid, after saturation with hydrosulphurio acid, in a nearly
air-tight vessel, and leaving it in a warm phice for 6 or 8 days; (2)
saturating it anew from time to time with hydrosulphurio acid (because,
if the saturation be not complete, the acid liquid redissolves a portion of
aisenie from the arsenious sulphide); and (3) filtering the liquid from the
precipitate before driving off the excess of hydrosulphurio acid. IT
b. With Basic Metallic Sulphides, forming a class of sulphur-salts,
called SuLPHARSENiTES. — Combination takes place in three different pro-
portions: e.g., in the case of potassium: 3KS,AsS'; 2KS,A8S'; KS^AsS';
forming respectively terbask or tris-acid, bvbakic or di-acid, and monobcuic,
or nunuhcLctd sulpharscnites. [The first of these must be regarded as the
normal salt]
containing
them out of contact of air. — 2. By dissolving ^ ,
warm aqueous solution of the protosulphide of an alkali-metal, or of the
double sulphide of hydrogen and the metal (alkaline monohydrosulphate
or bibydrosulphate). The solution in aqueous sulphide of ammoniqm is
attended with some rise of temperature (H. Rose.) When an alkaline
bihydrosulphate is used, half of the hydrosulphurio acid is expelled.
When complete saturation is attained, one atom of orpiment dissolves in
one atom of ammonium-, potassium-, or sodium-sulphide, and in 2 atoms
of barium-, strontium-, calcium-, or magnesium-sulphide. — 3. By dissolving
orpiment in a cold aqueous solution of an alkaJi. Under these circum-
stances, part of the alkali is converted into arsenite of potash, which
remains mixed with the snlpharsenite: e.g.
AAa& + 5KO - 3(KS, AaS^) + 2KO, A»0>.
Hence, when this solution is mixed with one of the stronger acids, no snl*
phuretted hydrogen is evolved, but the whole of the arsenic is separated
in the form of arsenious sulphide:
3(KS, AsS^) + 2KO, AsC + 5S0» = 5(K0. S0») + 4AsS^.
If the solution first obtained were heated with excess of tersnlphide of
arsenic, that compound would be converted into bisulphide, and the sul-
pharsenite of potassium into sulpharseniate. — 4. By dissolving arsenions
acid in the aqueous solution of an alk^kUne bihydrosulphate. B hih^dro-
sulphate of ammonia be used, half of the ammonia remains in the uqoid
in the free state :
2(NH',2HS) + AgO» = NH%AsS>+NEP+3H0.
t2
276 ASSENia
When the potassium componnd is used, half of the potash is conrerted
into arsenite :
2(KS, HS) + 2 AsOS = KS, JkE& + KO, AbO^ + 2H0.
5. The compounds of sulpharsenions acid with the sulphides of the earth-
metals and heayy metals are ohtained by precipitating a solution of the
corresponding compound of an alkali-metal, obtained by either of the
methods 2, S, 4, with a salt of the earth-metal or heavy metal. (Berzelius.)
The snlpbarsenites are either yellow or red. Most of them, when
ignited out of contact of air, give off all their sulphur- acid; others give up
such a quantity that the residue contains 3 At. sulphur-base to 1 At. sul-
phur-acid; but the snlpbarsenites of the alkali- metals, even those which
contain equal numbers of atoms of base and acid, give off nothing when
ignited. The alkali-metal compounds obtained by the first method, when
treated with a small quantity of water — and the dilute solutions obtained
by method 2, 3, or 4, when they evaporate in the air — are resolved into
brown hyposulpharsenite which is precipitated, and suipharseniate which
remains in solution; but the decomposition is not complete, till the solution
is concentrated to the crystallizing point of the latter salt. If the decom-
posed mass be digested in a large quantity of water and boiled, the whole
is reconverted into sulpharsenite and redissolved. The solutions of the
barium, strontium, calcium, and magnesium salts, containing I As. base to
1 At. acid, deposit, on boiling, a portion of the arsenious sulphide; the
ammonium, potcissium, sodium, and lithium compounds remain undecom-
posed. On adding alcohol to the aqueous solution of a compound of
1 atom of arsenious sulphide with 2 atoms of the sulphide of an alkali-metal,
a compound containing 3 atoms of sulphur-base is precipitated, while a
compound containing 1 atom of sulphur-base remains in solution:
2(2KS,AsSS) = 3KS,AsS3-i-KS,AsS^.
But the precipitated terbasic salt soon turns black, being resolved into
hyposulpnarsenite and suipharseniate. The potassium and sodium com-
pounds exhibit this blackening on the addition of alcohol, even when the
solution contains nothing but terbasic salt (3KS, AsS') ; but with the am-
monium, barium, strontium, and calcium salts, it does not take place
unless the solution contains bibasic salt (2BaS,AsS'). — Aqueous solutions
of sulpharsenites expOHed to the air are decomposed by oxidation (more
slowly in proportion to the excess of sulphur-base), depositing orpiment
and a brown compound of bisulphide of arsenic with the sulphur-base.
Hydrated oxide of copper, added to a solution containing a compound of
snlpharsenious acid with the sulphide of an alkali-metal, decomposes that
compound, yielding twelve-basic sulpharsenite of copper, which remains
undissolved, and a nyacinth-red solution, containing an alkaline arsenite
and terbasic sulpharsenite of copper, and deposits the latter on the addi-
tion of hydrochloric acid. Probably thus;
9(KS,A8S«) + 27CuO = 2(12CttS,AsS»)-H3CaS,AaS« + 9KO,6A80a.
If the hydrated oxide of copper is in excess, the arsenious acid contained
in the solution is converted into arsenic acid, and the protoxide of copper
reduced to di-oxide. Oxide of silver in excess decomposes the solution,
forming sulphide of silver and alkaline arsenite:
KS, AsS» + 4 AgO = 4 AgS + KG, AsO*. *
SULPHARSENIATES, 27 7.
Acids added to these solutions precipitate arsenious 8u]pbide, and resolve
the sulphide of the alkali-metal into an alkaline salt and hydrosulphurio
acid gas. (Berzelius.)
The only sulpharaenites which are soluble in water are those which
contain the sulphides of the alkali-metals or of magnesium; and even
these are decomposed by water, unless the water is in considerable quan*
titj (p. 276). Hence the solution cannot be evaporated to dryness to
obtain the dry salt, without undergoing decomposition. The solution is
colourless^-or yellowish^ if it contains a large quantity of sulpharsenious
acid; its taste is hepatic at first, but afterwards most disgustingly bitter.
(Berzelius.) It may be supposed to contain a compound of an alkaline
hydrosnlphate with hydrosulphate of arsenious acid; e. g,
KS,AsS> + 4H0 s KO^HS-f A803,3HS.
D. Pentasulphide of Arsenic; Arsenic Sulphide (Berzelius);
SuLPH ARSENIC Acio (Graham). — Formed in the decomposition of arsenic
acid by hydrosulphurio acid — a reaction which takes place the more
slowly, as the solution of arsenic acid is more dilute. (Sm, 44.) — Frepa-
ration. — 1. Hydrosulphurio acid gas is passed for several days through a
not very dilute solution of arsenic acid, till the liquid, after being kept in
a stoppered bottle for 24 hours, still smells of the gas. — 2. Aqueous arsenic
acid or arseniate of potash is mixed with bihydrosulphate of potash, or
aqueous arseniate of potash is saturated with hydrosulphurio acid gas,
and after the solution has stood for an hour, the pentasulphide of arsenic
is precipitated by hydrochloric acid. (Berzelius.)
Lemon-yellow powder, lighter than the tersulphide, and without any
tinge of red. Fuses less easily than sulphur, and after fusion appears
danger and somewhat reddish. Sublimes unchanged in the form of a red-
brown viscid mass, which, after cooling, appears transparent and pale yel-
lowish red. In the state of fine powder, it reddens tincture of litmus at a
boiling heat, but not in the cold, though the hot liquid remains slightly
red after cooling; it likewise imparts a transient redness to litmus-paper
on which it is laid, provided the vapour of boiling water is also brought
in contact with the paper. (Berzelius.) If a solution of arsenic sulphide
in ammonia be precipitated by nitrate of silver, and nitric acid cautiously
added to the filtered liquid till the ammonia is neutralized, a red-brown
precipitate of arseniate of silver is thrown down; arsenious sulphide treated
m the same manner gives a yellow precipitate of arsenite ol silver. (H.
Rose.)
Am 75 48-39
5S 80 51-61
AsS* 155 100-00
In the nnfnsed state, it yields a small quantity of sulphur to boilinff
alcohol, and becomes darker in colour. l)issolve8 easily, with partial
decomposition (vid, inf.) in aqueous solutions of the pure fixed alkalis and
of their hydrosulphates and carbonates, driving out the carbonic acid from
the latter on the application of heat. Dissolves completely in concen-
trated aqueous ammonia, but if digested in more dilute ammonia, leaves a
residue of sulphur. Not soluble in boiling water.
Towards bgsic metallic sulphides, pentasulphide of arsenic plays the
part of an acid, and forms with them a class of sulphur-salts, called
SuLPHARSBNiATES. In thoso salts^ 1 atom of arsenic sulphide ii9 combined
278 ARSBNTC.
with 1, 2, or 3 atoms of tbe basic sulphide; e. ff,, KS, AsS*; fiKS, AsS*;
SKS, AsS'; so that, in this ease also, we hare to distinguish between
monobasic, bihasic, and terbd^ic salts. — Preparation, — 1. By diasolviog
pentasulphide of arsenic in a warm solution of an alkaline monohydrosul-
phate or bihydrosnlphate. In the latter case, the second atom of hydro-
snlpharic actd is driven off, with brisk effervescence. The solution con*
tains a bibasic salt; e, g., 2KS, A8S^ It is only by longer digestion with
excess of the pentasulphide, that a larger quantity of it is dissolved, and
in that case, the quantity taken up increases with the temperature and
concentration of the liquid; part of it is, however, precipitated as the
liquid cools, so that ultimately, not more than } At. sulpharsenic acid
remains dissolved, in combination with i At. sulphur-base. — (Pentasul-
phide of arsenic being a stronger acid than the tersulphide, its solution in
hydrosulphate of ammonia is attended with greater rise of temperature
than that of the tersulphide: ff. Rose.) — 2. By passing hy^drosulphuric
acid gas through the aqueous solution of an aikidine arseniate — where-
upon, the gas is absorbed slowly at first, but afterwards more quickly—
till the liquid no longer gives a precipitate with chlorido of barium or
calcium:
2KO,AsO*+7HS ::= 2KS,AsS<^ + 7HO.
Or by mixing the solution of an alkaline arseniate with excess of bihydro*
sulphate of ammonia, and distilling till the free ammonia and excess of
hydrosulphate of ammonia are expelled. — 9. If the arseniate used is
insoluble in water, that of copper, for example, it must be dissolved
in hydrochloric acid, and the sulpharseniate of copper precipitated by
sulphuretted hydrogen. — 4. By fusing pentasulphide of arsenic with a
pure caustic alkali, or with its hydrate or carbonate. Under these cir-
cumstances, arsenic sublimes, and the sulphur-salt produced is mixed with
arseniate and sulphate of the alkali. — 5. By dissolving the pentasulphide
in caustic alkali (or in alkaline carbonate at a boiling heat, the carbonic
acid being then driven off.) In this case, an alkaline arseniate is always
formed at the same time. Probably in this manner :
14KO + 7AsS< «= 5(2KS,AsS*) + 2(2KO«AbO*).
Consequently, this solution evolves no hydrosulphuric acid when the
arsenic sulphide is precipitated by a stronger acid :
5(2KS, AiS^ + 2(2KO, AsO») + 14S0» « 14(KO,SO«) + 7AbS»,
6. By digesting orpiment in an aqueous solution of bisulphide, or a higher
sulphide of potassium; in the latter case, the excess of sulphur is precipi-
tated. — 7. The compounds of sulpharsenic acid with sulphides of certain
of the earth-metals and heavy metals, are obtained by precipitating a salt
of one of theso metals with solution of sulpharseniate of potassium.
Magnesium, yttrium, glucinum, and some of the heavy metals, however,
yield soluble compounds. (Berselius.)
The dry compounds of the alkali-metals are lemon-yellow; the others
red or brown. They are permanent in the air; taste — in so (ar as they are
soluble — first hepatic, and afterwaids most intensely bitter. The terbasic
salts have a tendency to crystallize; the bibasic and monobasic salts have not.
The terbasic snlpharseniates of potassium, sodium, lithium, and barium
may, if air be excluded, be heated almost to whiteness without decom-
posing ; on cooling they solidify to a j^llow mass, perfectly soluble in
water. The bibasic and monobasic sulpharseniates oif these metala give
OCTOD£CA-i;ULPHU)E OF ARSENIC. 279
off sulphur when heated^ and are converted into solpharsenites. The
silver and mercury salts (the latter of which sublimes) remain undecom-
posed at a red heat. The other bibasic and monobasic sulpharseniates are
decomposed by ignition, first yielding sulphur and a red salt of sulphar-
senious acid; and in many cases, the sulpharsenite is resolved by con-
tinued ignition into sulpharsenious acid which sublimes, and the sulphur-
base which remains behind. The calcium and magnesium salts first
evolve sulphur, and then the greater part of the sulpharsenious acid, and
leave a white unfused compound of magnesium- or calcium-sulphide, with
a very small quantity of sulpharsenious acid; most of the heavy metal
compounds evolve sulphur at first, and then all the sulphide of arsenic, so
that nothing but the sulphur-base remains behind. The sulpharseniates,
when heated in the air, give off orpiment and arsenious acid, and leave a
sulphate when the base contains an alkali-metal, imd pure oxide if it con-
tains a heavy metal. The aqueous solution of the sulpharseniate of an
alkali-metal is decomposed by exposure to the air — the liquid becominfi"
turbid, and depositing 6ul{^ttr, sulpharsenic acid, and a brown salt of
hyposulpharsenious acid, while alkaline arsenite and hyposulphite are
formed, and the latter, by further oxidation, is converted into sulphate ;
the cooler and more concentrated the solution, the more slowly does the
decomposition proceed. Acids, even carbonic acid, decompose the alkaline
sulpharseniates, separating hydrosulphuric acid gas of a peculiar odour,
and precipitating pentasnlphide of arsenic. Hydrate of cupric oxide,
introduced into the solution of an alkaline sulpnarseniate, decomposes a
portion of that compound, forming alkaline arseniate and sulphide of cop-
per; the latter combines with a small portion of undecomposed arsenic
sulphide, forming a compound which is insolnble in water, but nevertheless
dissolves partially in the liquid, provided that this liquid still contains
undecomposed alkaline sulpharseniate — while sulphide of copper, contain-
ing little or no sulphuric acid, remains behind. A similar reaction is
produced by other heavy metallic oxides which do. not retain their oxygen
with very great force. (Berzelius.)
Many sulpharseniates are soluble in water, namely, those of the
alkali-metals, magnesium, yttrinm, and glucinum. The solutions are
either colourless or pale yellow. From the solutions of the bibasio salts,
alcohol precipitates a terbasic salt, leaving a monobasic salt in solution.
When this solution is placed in a shallow msh, and evaporated at a gentle
heat, there remains a lemon-yellow residue, from which water extracts a
bibasic salt, while arsenic sulphide is left behind, and is but partially dis-
solved by continued digestion. When the abovo-mentioned alcoholic solulioa
is heated in a retort to the boiling point, it deposits half the arsenic sul-
phide which it contains, but at the same time resolves it into two other
compounds, viz., tersulphide of arsenic in the form of a reddish powdek*,
and octodecaHsulphide of arsenic in the form of pale y«Uow scaleSi
(Berzelius.)
E. OcTODECA-suLPHiDE OF Arsenic. — 1. Obtained by precipitating
the solution of bibasic sulpharseniate of potassium with alcohol, distilling
I or f of the alcohol from the filtrate, and leaving the solution to crys-
tallize by slow cooling. — 2. A still larger quantity of this compound is
obtained by digesting orpiment with an alcoholic solfition of potash-
fiver of sulphur. Delicate pale yellow scales and fibres. (Berseiios.)
• * * V * • -.
280 ARSBNIC.
Calcnktioii.
As 75 .... 20-66 20-61
188 288 .... 79-34 79*39
AaS» 363 .... 100-00 ~, 100-00
F. Persulphide of Ab£EMIC. — ^Arsenions acid may be fused with
any excess whatever of snlphnr; salpharons acid is erolyed^ and a brown-
ish yellow sulphide of arsenic formed, which on cooling after fusion^
remains soft for a long time : its powder is yellow, the brightness of the
colour increasing with the quantity of arsenic On distilling a compound
of this nature, sulphur passes over, accompanied by a continually increas-
ing quantity of arsenic. (Berzelius.) Much of Uie ordinary sulphur of
commerce is really a compound of this nature.
% G. SuLPHOxT ARSENIC AciD,— AsO'S*. — When hydrosulphuric
acid gas is rapidly passed through a cold saturated solution of bi-arseniate
of potash, pentasulphide of arsenic is first precipitated, and afterwards
a white salt is deposited. After this deposition has gone on for some
time, a small quantity of caustic potash is added, and hydrosulphuric
acid again passed through till the sulphide of arsenic acquires a grey
colour. If the liquid be then filtered and eyaporated in vacuo, crystals
are obtained, which m^ be freed from adhering sulphide of arsenic by
washing with water. These crystals consist of StUpluMnarsenieUe of potcuh^
KO,AsO'S*-h2HO (vid. p. 294). When the aqueous solution of this
salt is mixed with a lead salt, a white precipitate is obtained, which,
however, soon turns black. On suspending this precipitate in water,
adding a few drops of sulphuric acid, and filtering, an acid liquid is
obtained, which does not precipitate baryta-salts, but quickly decomposes
and yields a deposit of sulphur. The acid thus formed may be regarded
as arsenic acid, in which 2 atoms of oxygen are replaced by sulphur.
(Bouquet & Cloez, N. Ann. Chim. Phyt. 13, 44; J. Pluirm. 7, 23;
abstr. Ann. Fharm. 56, 216.) IT
H. Sulphate op Absenious Acid. — Oil of vitriol heated with
arsenic gives off sulphurous acid, and leaves a residue which forms a
milky precipitate with water, and contains arsenious but no arsenic acid.
—Three parts of boiling oil of vitriol dissolve 1 part of arsenious acid;
of this the greater part crystallizes out on cooling, and a further portion
may be precipitated by alwolute alcohol ; a small quantity, however, still
remains dissolved. When the solution of arsenious acid in oil of vitriol
is distilled, the sulphuric acid passes x)ver quite free from arsenic, and
the arsenious acid remains behind, not converted into arsenic acid. (A.
Vogel. J. pr. Chem. 4, 232.) According to Wackenroder, part of the
arsenious acid does pass over with the sulphuric acid in distillation.
According to Bucholz {Beitr. 1, 61), the residue contains a small
quantity of arsenic acid.
Arsenic and Selenium,
Sblenide op Arsenic. — Selenium in the state of fusion gradually
dissolves arsenic, forming with it a black, easily fusible mass, which boi(s
at a red heat, and appears to give off a perselenide of arsenic; after-
IODIDE OF ARSENIC. 281
wards the boiling ceases, and no farther change takes place till the heat
is raised nearly to whiteness, at which temperature the entire compound
distils oyer in drops, which solidify in a brown-black shining mass^
haying a conchoidal fracture. (Beneuus.)
Arsenic and Iodine.
A. Teriodibe of ARflENic— Arsenic powder yery gently heated
with iodine powder combines with it^ producing great rise of tempera-
ture. — FreparcUion. — 1. By heating a finely diyided mixture of 16 parts
of arsenic and 100 parts of iodine till it fuses. The compound thus
formed contains excess of iodine. (Plisson.) — Thomson gently heats
75'2 parts (1 At.) of arsenic with 630 parts (5 At.) of iodme, and
obtains the same compound ; for this reason, he regards it as penta-iodide
of arsenic. [Was part of the iodine driyen off by the heat?] — By
heating a mixture of arsenic and excess of iodine in a retort, till subli-
mation or distillation takes place. (Plisson.) Serullas & Hottot distil
1 part of arsenic in a retort with 3 parts of iodine. Bette sublimes
1 part of arsenic with 3 parts of iodine in a glass flask, and as the
sublimate often falls down i^in, allows the flask to cool from time
to time in order to remoye the sublimate ; when the sublimation takes
place in yessels containing air, a small quantity of arsenious acid
becomes mixed (according to Bette), with the sublimed iodide. — 3. Three
parts of pulyerixed arsenic are heated with 10 parts of iodine and with
water, till the liquid no longer smells of iodine, and retains merely a
pale yellow colour; it is then filtered from undissolved arsenic, and left
to evaporate in the sunshine till the iodide of arsenic crystallizes out. As
soon as the crystals have become tolerably dry, they are melted in a
fiask to drive off the water which adheres to them. (Plisson.) On
dissolving the fused mixture of 1 part of arsenic and 3 parts of iodine
in water, and evaporating the yellowish red filtrate to dryness over a
water-bath, white and violet vapours are given off, and there remains a
brick-red powder consisting of iodide of arsenic, which, however, is
mixed with arsenious acid, and, when exposed to the air, evolves iodine,
and turns brown-red. (Bette.)— 4. The mixture obtained by fusing the
arsenic and iodine together, is dissolved in hot alcohol, and filtered from
the arsenious acid which separates from it ; the yellowish red filtrate is
then cooled down the c^stallizing point, and the red laminao which
crystallize out, are dried between folds of bibulous paper frequently
changed, till they no^ longer smell of iodine. By this process, the com- "^
pound is obtained pure, but in small quantity : the black-brown mother-
liquid, which contains free hydriodic acid, deposits nothing when left to
itself. (Bette.) IT 5, Meurer passes pure arseniuretted hydrogen ras
(prepared from arsenide of zinc and hydrochloric acid) through a freshly
prepared alcoholic solution of iodine, but only till the liquid is decolorized.
On evaporating the solution, iodide of arsenic separates in crystals.
(Arch. Fharm. 2nd series, 52, 1.) IT
Fropetiies. — ^By method (1): brick-red mass, with crystalline fracture
(Plisson); red-brown, with violet fracture (Bette); by (3): small red
crystals, which assume a darker colour on diying (Plisson) ; by (2) and
(4\: light brick-red, shining laminss. Fuses when heated, and afterwards
sttUimes, with slight decomposition, in yellow vapours which condense
in scales. Inodorous. (Plisson.) Tastes somewhat metallic. (Thofo^fQp,)
282 ARSSKIC.
(«,•) (2,5) (S) (4)
As 7a .... 16-56 .... 15-9 .... 15 .... 16*4 .... 1746
31 3^8 .... 83-44 .... 84*1 .... 85 .^. 83'6 ...^ 82*34
A8l» ........ 453 .... 100-00 .... lOO-O .... 100 .... lOO'O Z 99 74
The numbers refer to the modes of preparation ; 2, a is iodide of
arsenic obtained bj sablinrntioiu ; %, b i« the same sublimed a second
time. The specimen 4 was half a year old, and had given off some
of its iodinei
DeoomposUions. — Daring sublimation, a very small portion of the
compound is resolved into tree iodine and arsenic, and the latter, if the
air has access to it, is conyerted into arsenious acid. (Plisson.) If the
beat be suddenly raised to 138°, more complete decomposition ensues.
(Thomson.) — When kept in glass- vessels which are frequently opened,
it loses a portion of its iodine in the course of a few months, without,
however, changing colour. (Bette.) — 3. When evaporated with nitric acid,
it leaves all the arsenic in the form of arsenic acid. (Plisson.) — 4. Iodide
of arsenic treated with a small quantity of cold water, is resolved into
the acid compound C which dissolves, and the basic compound B which
separates in scales. A small quantity of hot water dissolves it^ but on
cooling, it is decomposed in the same manner. (Plisson.)
Jque&ui Teriodide of Arsenic, or AqueouB HydiiocUUe of ArseniouB
Acid, — Iodide of arsenic dissolves perfectly in considerable qaautities of
cold water, either without change of composition, or as a compound of
hydriodic acid with arsenious acid: AsPH-3H0=A80*-f 3Hl. The
yellow solution reddens litmus strongly. It does not flike free hydriodic
acid) turn brown in the air, neither does it evolve iodine ; hence it does
not impart a blue colour to starch-paper suspended over it, except on the
addition of hydrochloric acid. Hence it appears, that the hydriodic acid,
if it exists in the solution, is in combination with the arsenious acid.
When the liquid is boiled in a retort, iodide of arsenic remains behind,
and the aqueous vapour carries with it a small quantity of that com*
pound, but no free iodine or free hydriodic acid. By free evaporation in
an open vessel, on the contrary, the solution is resolved into soiles of the
basic compound B, and a mother-liquid containing the acid , compound G.
Sulphuric and nitric acid added to tne solution precipitate iodine ; hydro-
sulphuric acid precipitates tersulphide of arsenic. The solution gives a
brown precipitate with nitrate of bismuth, yellow with acetate of lead,
green with ammonio-sulphate of copper; none with sulphate of lime.
(Plisson, Ann, Chim, Phys, 30, 265] also Pogg. 14, 608.)
B. Absenitk of Teriodide of Arsenic. — Produced in the decom-
position of teriodide of arsenic with a small quantity of water. With
cold water, the separation takes place immediately; with hot water, not
till the solution cools. The compound is prepared by saturating hot
water with iodide of arsenic, and leaving the solution to cool slowly.
(Plisson.) To free the crystalline scales from adhering acid mother-
liquid, they must be washed with a small quantity of water, or better
with alcohol, in which they are much less soluble. (Semllas & Hottot.)
When the white scales thus obtained are gently heated, they give off
their water, and are converted into a yellow powder, which, if the heat
be increased, yields a sublimate of teriodide of arsenic with a small
quantity of arsenious acid, while the greater part of the arsenious acid
rimaitts behind* The residue has a greyish tinge, . probably from a4mix«
BROMIDE OF ARSENIC* 283
ture of metallic arsenic. (Plisson.) The scales^ if well washed with
alcohol, and afterwards strongly heated, give off a considerable quantity
of metallic arsenic, together with teriodide of arsenic, bnt without Any
violet vapour or arsenious acid. (Serullas & Hottot.) [The separation of
metallic arsenic is probably due to the alcohol.] This compound retains
a portion of water, even when heated till decomposition commences.
(Serullas.) — The scales are large, white, shining, and permanent in the
air. (Plisson.) It is only when some of the acid mother-liquid still
adheres to them, that they turn red in the air. (Serullas <b Hottot.) They
contain water of crystalliEation, which they do not give off, even in vacuo
over chloride of calcium. Hence they may likewise be regarded as a
compound of 3 atoms of hydriodic acid with more than 1 atom of arsenious
acid. — The scales dissolve more readily in hot water than in cold, and
crystallize from the hot solution as it cools; but on each successive crystal-
lisation, the proportion of hydriodic acid diminishes and that of arsenious
acid increases, so that no definite combining proportion can be made out.
After very long washing with alcohol, the scales leave only 1*25 per
cent, iodine and 98'75 per cent, arsenious acid. (Plisson.) — The aqueous
solution of the scales behaves with sulphuric acid, nitric acid, hydro*
sulphuric acid, and heavy metallic salts, just like the solution of teriodide
of arsenic. (Plisson.) The : scales are but slightly soluble in cold water,
and still less soluble in alcohol. (Serullas & Hottot.)
C. Hydriodale of Teriodide ofAnenic^ or Acid Hydriodode of Arsenious
Acid. — Contained in the aqueous solution which remains after the sepa-
ration of the scales B, in the decomposition of teriodide of arsenic by a
small quantity of water. (Plisson.) The reddish, highly acid liquid may
be decomposed by repeated distillation into free hydriodic acid and the
scales B. (Serullas & Hottot.)
D. Aqueous Penta-iodide of Arsenic, or Aqtieous HydriodUe of Arse"
nion;s Acid ? — The aqueous solution of teriodide of ai*senic dissolves a
large quantity of iodine. The solution, when evaporated in vacuo over
oil of vitriol, first deposits acute octohedrons of iodine, and afterwards the
scales B. (Plisson.)
On the relations between iodine and arsenic compare Plisson (J.
Pkarm. 14, 46; Ann, Chim. Fhys. 39, 265; also JSchtff, 55, S35;J, Pkarm,
14, 592). Serullas & Hottot {J, Pkarm. 14, 49, 163, 165, and 598).
Serullas {Ann, Chim. Phys. 38, 319; also S<^w. 55, 345). Todd Thomson
{BepeH. 67, 860). Bette {Ann. Pharm, 33, 349.)
•
Arsekio akd Bromine.
A. Tbrb&omidb op Arsenic.— Arsenic takes fire as soon as it comes
in contact with bromine, burning wiUi great brilliancy, and giying off
dense fumes. To prepare the bromide, bromine is put into a retort and
dry arsenic powder introduced through the tubulure in successive smaU
portions, agitating each time, till the combustion ceases; the bromide of
arsenic is afterwards distilled from the excess of arsenic. The distillate
crystallizes on cooling, and forms a white fibrous mass, which, between
20*^ and 23°, fuses to a translucent pale-yellow liquid, boils at 220"^, and
in the fused state, fumes but slightly in the air. it absorbs moisture from
the air, and, in contact with water, is instantly resolved into a solution of
1
284 ARSENIC.
a small quantity of arsdnions in a large quantity of hydrobromio acid, and
the compound B which is precipitat^. (Serullas, Ann. Chim. Fhyi. d8|
319; also Sckw. bS, 345.)
Calcnlatknii aocording to Sernllas.
As 750 24-18
3Br 235-2 75*82
AaBr» 310-2 10000
B. Absbkitb of Bromide of Arsenic. — Precipitated in the decom-
position of bromide of arsenic bj water. Retains water even when
neated to incipient decomposition, and consequently, when more strongly
heated, gives off water, as well bromide of arsenic and arsenious acid.
Hence it may likewise be regarded as a compound of 3 atoms of hydro-
bromio acid with more than one atom of arsenious acid. When repeatedly
washed with water (or better with alcohol), which dissolves less of the
arsenious acid, it gives off all its bromine in the form of hydrobromio
acid, so that nothing but arsenious acid remains behind. (Seruflas.)
Arsenic and Chlorine.
A. Terchloride of Arsenic. — Ar$enic-^bvUer^ Caustic Oil of Arsenic.
-^1. Arsenic powder thrown into chlorine gas at ordinary temperatures,
bums with a reddish white light, forming white vapours of chloride of
arsenic. — 2. It decomposes chloride of mercury at high temperatures,
abstracting the chlorine.
Preparation. — Dry chlorine gas is passed into a tube-funnel containing
pounded arsenic, and having its beak turned down and inserted into a
receiver containing ice. The distillate is freed by rectification over
arsenic from any excess of chlorine that it may contam. (Damas.) — 2. By
distilling a saturated solution of arsenious acid in concentrated hydro-
chloric acid with oil of vitriol. (J. Davy.) — 3. By distilling arsenious
acid with common salt and oil of vitriol. (Gm.) Dumas heats in a retort
40 grammes of arsenious acid with 400 grammes of oil of vitriol, at a
temperature between 80"" and lOO"", and introduces pieces of fused common
salt from time to time through the tubulure of the retort. Little or no
hydrochloric acid is evolved; dry chloride of arsenic passes over first,
and afterwards the hydrated compound, which forms a separate stratum
in the receiver above the dry chloride; the hydrated chloride may be
rendered anhydroas by repeated distillation with a large quantity of oil
of vitriol. — 4. By distilling one part of arsenic, at a gentle heat, with
6 parts of protochloride of mercury.
Transparent, colourless, oily, and very heavy liquid; does not solidify
even at —29^ (J. Davy.^ Boils at 132^ Specific gravity of the
vapour = 6*3006. (Dumas.) Evaporates in the air at ordinary tempe-
ratures, producing white fumes. (J. Davy.) Highly poisonous.
Calculation. J. Davy.
As 75-0 .... 41-39 .... 39-52
3C1 106-2 .... 58-61 .... 60 48
AiCP 181-2 Z 100-00 Z. 100-00
CHLORIDB OF ARSENIC. 285
Vol. 8p. gr. Vol. Sp. gr.
Anenic vapour 1 10*3995 = J 2*5999
Chlorine gas 6 14-7258 = } 3-6814
Chlor. araen. Tapovr 4 25*1253 s= 1 6-2813
Antimony, bismnth, zinc, cadmiam, tin, lead, iron, and copper, im-
mersed in chloride of arsenic, become covered with a crust of metallic
arsenic, which prevents further decomposition. (Fischer, Fogg, 9, 261.)
Mercury likewise, at ordinary temperatures, decomposes chloride of arsenic
very slowly, forming a greyish brown powder. (Dumas, Ann, Chim, PhyB.
38, 337; also Pogg. 9, 313.)
Chloride of arsenic dissolves phosphorus at a gentle heat, without
becoming luminous, and deposits it again almost completely on cooling.
When heated, it dissolves sulphur in almost all proportions, but the
sulphur is almost wholly precipitated on cooling. It absorbs 10 times
its volume of phosgene gas, which is again evolved on mixing the liquid
with water. Dissolves oil of turpentine, olive oil, and colophony. (J.
Davy, Schw. 10, 332.)
Hydrated Terchloride of Arsenic or TerhydroMorate of A rseniotu Acid.
— 1 . Formed by mixing chloride of arsenic with a small quantity of water :
AsCP + 3H0= AsO' + 3HC1.— 2. In the distillation of chloride of arsenic
as in (3) p. 284. — 3. By dissolving arsenious acid in strong hydro-
chloric acid.—- Transparent, colourless, heavy liquid, lighter but more
viscid (according tcPDumas) than chloride of arsenic. On the addition
of a larger quantitji^f water, it is resolved, like the anhydrous chloride,
into arsenious acid/ which is precipitated, and dilute hydrochloric acid,
containing a small quantity of either chloride of arsenic or arsenious acid
in solution. The same liquid is obtained on dissolving arsenious acid in
dilute hydrochloric acid. A solution of this nature, if it contains a large
excess of hydrochloric acid, evaporates completely, without leaving arse-
nious acid behind. (Dupasquier.) If therefore hydrochloric acid con-
taining arsenious acid in solution be distilled, the distillate contains
arsenic. Similarly, when common salt is distilled with sulphuric acid
which contains arsenious acid, the hydrochloric acid obtained is likewise
contaminated with arsenic. (Dupasquier, J, Pkarm. 27, 717.)
When dry chlorine gaa in large excess is brought in contact with
pulverized arsenic, terchloride of arsenic is formed at first, but at last
there is produced a small quantity of a white crystalline substance, which
may perhaps be PentacMoride of Arsenic. (Dumas.) According to
Capitaine {J. Pharm. 5, 524), the small crystals thus formed consist of
arsenious acid, proceeding from a small quantity of moisture in the
chlorine, and are produced in but very small quantity if the chloride of
calcium tube used to dry the chlorine is very long. When common salt
is distilled with arseniate of potash and a large excess of oil of vitriol, a
considerable quantity of chlorine is evolved and terchloride of arsenic is
the only product. (Liebig & W6h\er,Pogg. 11, 49.) Similarly, if arsenic
acid be used instead of arseniate of potash. (H. Bose, Pogg. 52, 64;
Capitaine.) Rose likewise obtained nothing but terchloride of arsenic ou
treating metallic arsenic with excess of chlorine.
B. Chlobidb of Sulphur and Arsenic. — Entire lumps of ter-
sulphide of arsenic exposed to dry chlorine gas, deliquesce, with con-
siderable development of heat, and are converted into a brown
liquid, which refuses to take up more chlorine. This liquid dissolves
286 ARaNiC,
completely in dilute nitric ftcid, giving off nitrons acid vaponrs^ and
forming a solution of sulphurioy hydrochloric^ and arsenions acid. With
water, it forms a solution oontaining hydrochloric, sulphuric, hypo-
sulphnroQS, and arsenious acid, the hjposulphurons acid being however
quickly resolved into sulphurous acid and precipitated sulphur. The
solutioB of this compound in aqueous ammonia is rendered vilky ^y
sulphuric acid: it likewise contains hyposulphurous acid. (H. Rose, Pogg.
42, 59%. )
H. Rose.
As 75-0 .... 22-36
3S 480 .... 14-31 ^ 13-68
^^_ 6C1 212-4 .... 63-33 6310
A»C1» + 3SCI 335-4 .... 10000
Bisulphide of arsenic behaves in a similar manner, forming a yellowish
liquid with a small quantity of chlorine, and a brown liquid with a
larger quantity. (H. Rose.)
ABSBino AND Fiiuonmx.
Tbrfluoridb or Abssnio. — ^Formed by mixing 1 part of i^^ited
fluorspar with 1 part of arsenious acid and 3 parts of oil of vitriol in a
leaden retort, and heating the mixture till it boils. Transparent, colour-
less, thin liquid, of specific gravity 2'7d, Boils at 63°; fumes veiy
strongly in the air even at ordinary temperatures; smells like fluoride of
silicium, without any garlic odour; reddens litmus paper, if moisture has
access to it, but uot otherwise. (Unverdorben.) Fluoride of arsenic is
very volatile. The specific gravity of the vapour is at least four times
as great as that of air. A drop coming in contact with the skin-^
although it evaporates almost instantly, and in so doing produces a
sensation of cold, like ether — ^nevertheless excites inflammation and pro-
tracted suppuration of the part, just like a bum ; the vigour also produces
a painful sensation under the naUs, jost as hydrofluoric acid does. (Dumas,
Ann. Chim. Fhys. 31, 434.)
As
3F
Calcalation.
75-0 57^21
66-1 42-79
59-28
40-72
AsF*
131-1 100-00
100-00
Zinc, tin, and carbonate of lime are scarcely attacked by fluoride of
arsenic; class, for the most part, only when moisture is also present. The
compound may therefore be kept for some time in glass vessels, in which
it aevelopes fluoride of silicium but slowly. It may be evaporated
without decomposition in a glass vessel, to which the air has not excess;
but if evaporated on glass in the open air, it is decomposed, the moisture
of the air acting upon it in such a manner, that arsenious acid is lefi
behind. It may be mixed — with more or less decomposition — with
alcohol and ether, and somewhat less easily with oils, both fixed and
volatile. It combines with ammonia. Mixes with water, forming a
clear liquid which scarcely attacks zinc or tin, but when kept in glass
ressels is decomposed, silica being dissolved and arsenious acid preci*-
pitated. (Unverdorben, If. Tr, 9, 1, 23; Fogg, 7, 316.)
ARSENIATS 0? AHMONU. 28T
Absenig and Nitrooek.
A. Arbenitb op Ammonia. — Volatile Liver of Anenic, Anenical
Sal-ammoniac. — ^Polverized, transparent arsenions acid becomes heated in
contact with aqueons ammonia. (Gniboart.) When aqueous ammonia is
poured upon pulverized arsenious acid, an acid compound l is produced, in
the form of a viscid crystalline deposit, and above it a liquid containing a
basic compound a. (Fischer.)
a. Banc Salt, — The above-mentioned solution, when exposed tp the
air, gives off ammonia and deposits arsenious acid. (Fischer.) Arsenious
acid dissolves abundantly in heated ammonia, but on cooling, is almost
wholly deposited in octohedrons which do not contain ammonia. (Berze-
lius.) On evaporating the eolation, Lassonne {CrelL Chem, J. 5, 80)
likewise obtained a great number of small crystals [probably consisting
merely of arsenious acid].
5. Acid Salt — The viscid mass which settles at the bottom of the
liquid. On warming the liquid and agitating it with the viscid mass till
the latter is dissolved, the salt h crystallizes out in rhombic prisms. The
salt 6, when exposed to the air, is likewise converted into arsenious acid.
It dissolves in water, and also, though less easilv, in a large excess of
ammonia. The aqueous solution gives very delicate reactions with
copper and silver sidts; a small quantity of alcohol precipitates arsenious
acid from it; a large quantity leaves it transparent. (Fischer, Ka^n. Arch,
11, 236.)
IT According to Pasteur, the crystalline mass obtained by pouring
strong ammonia on arsenious acid consists of NH^0,A80'j the crystals are
oblique rectangular prisms, having two of their lateral edges replaced by
planes, so that they look like hexagonal tables. This salt remains
permanent only when in contact with the ammoniacal solution; when
taken out or dissolved in water, it soon loses its ammonia; the aqueous
solution gives with nitrate of silver a yellow precipitate of 2Ag0,As0',
and the supertiatant liquid exhibits an acid reaction. %
B. Arseniate of Ammonia.— a. Triaarseniate. — The concentrated
solution of b mixed with ammonia, solidifies to a ma^ma of the salt a
which is less soluble; when exposed to the air, however, it quickly evolves
ammonia, and is reconvorted into 6. (Mitscherlich.)
6. DiarMeniatc^-^Formod by adding ammonia to a concentrated aqueous
solution of arsenious acid, tiU a precipitate is produced, and warming the
solution till the precipitate redissolves; the liquid, if left to itself for a
while, yields beautiful crystals. Any crystals that may form imme-
diately on cooling, consist of the salt a : these however are soon converted
into b by exposure to the air. (Mitscherlich.) The crystalline system
and form of diarseniate of ammonia agree precisely with those of diphos-
phate of ammonia. Therefore, Fig. 91, 98, 94, and 95; only with the
loliowing small angular differences; i' : the a»i» = 113^ 30^ ; i : u =
105° 46'; i :/= 70^ 54'; w : v = SS** 54'; >[:.<*€ a«M = 1 37^ 23^', Ac.
(Mitscherlich.) Colour, green like that of violet-juice. Gives off, when
heated, ammonia^ water, sublimed arsenic, and nitrogen gas. (Scheele.)
Effloresces in the air, giving off half its ammonia (no water) and being
converted into c. (Mitscheruoh.)
288 ARSENia
CryMUized. Mituihetlidi.
2NH» ^ 34 .... 19-32 +Aq. 34-7
AsO* 115 .... 65-34 .... 65-3
3H0 27 .... 15-34
2NH*,HO,AsO* + 2Aq 176 .... lOO'OO .... 100-0
c. lfofUHsr«»ifa^.— Formed by supersaturating ammonia with solu-
tion of arsenious add and evaporatinff. The salt which Maoquer obtained
by gently heating arsenious acid with nitrate of ammonia^ is probably
also a mono-arseniate. Large crystals, identical in form with monophos-
f>hate of ammonia. Fig. 23 and 30, with the same angles. (Mitscher-
ich.) Strongly acid reaction. When heated, it gives off water, arsenious
acid, and nitrogen gas, but no ammonia. (Berzelins.) Deliquescent and
yery easily soluble in water.
Cry$taUix9d, Mitsdierlich.
NH» 17 .... 10-69 +Aq. 27-78
AbO» 115 .... 72-33 .... 72-22
3HO 27 .... 16-98
NH»,2HO,AsO» + Aq 159 .... 10000 Z 100-00
C. Htposulpharsenitb qf Kuuovrvu,^--' ZwdfcuihrSckwfelarBen''
ammonium, Zweifcu^hMhwefdarieHf-Hydrt^icmammoniak.''^^ compound
of bisulphide of arsenic with sulphide of ammonium. A concentrated
solution of bibasic snlpharsenite of ammonium, kept for a long time in a
stoppered bottle, deposits the hyposulpharsenite on the sides of the yessel
in small, dark brown grains united into a crust. When distilled, it evolyes
[hydrosulphate of?] ammonia and leayes realgar. Absorbs ammoniacal
gas and becomes lighter-coloured in consequence, but giyes it off again
when exposed to the air. (Berzelius.)
D. Ammonio-Tersctlphidb of Arsenic. — Finely divided tersulphide
of arsenic slowly absorbs ammoniacal gas without alteration of external
appearance (Berzelius), the absorption going on for three, weeks before
saturation is attaineU. (Bineau, Ann, Ckim. Phys. 70, 264.) The
compound quickly gives off its ammonia in the air. Water extracts
from it a small quantity of arson ite of ammonia;, together with snlph-
arsenite of ammonium. (Berzelius.)
E. SuLPHARSENiTE OF hMMOViTTii, '^Drtifoch'Scfiwrfdarsenammo-'
nium, l)rHfach8chwrfelarim'ffydrothionammoniak,''''-a, Terbanc SaU.^
dNH^S,AsSl — Prepared by mixing a solution of orpiment in excess of
hydrosulphate of ammonia with alcohol, and washing the deposited
crystals with alcohol. White, light, feathery crystals, which, on expo-
sure to the air, turn yellow, give off hydrosulphate of ammonia, and leaye
a residue of orpiment with a trace of hydrosulphate of ammonia. (Ber-
zelius.)
6. BibasicSaU. — 2NH*S,AsS*. — 1. Formed by dissolving orpiment in
hydrosulphate of ammonia. The same solution, but containing free
ammonia is obtained : (2) by dissolving oipiment in pure ammonia or in
heated carbonate of ammonia; or (3) by dissolving arsenious acid in
bihydrosulphate of ammonia. The solution'obtained by the first method
leaves when spontaneously eyaporated, a brown pulyerulent mixture of
pentasulphide and a lower sulphide of arsenic; that obtained by (2)
leaves a reddish-yellow residue. Alcohol precipitates from the solution
^
ARSENIC AND AMMONIUM. 289
a white ciystalline substance, which turns brown after a few seconds;
if, however, it is mixed with bihjdrosulphate of ammonia, a milky
tnrbidit^ is first produced, and afterwards the compound a separates.
(Berzelios.)
F. Ammonio-pentasitlphide of Absenic. — Pentasulphide of arsenic
absorbs ammoniacal gas, and is thereby conrerted into a pale yellyw
sabstance, which gives np all its ammonia when exposed to the air
for a few hours, but is previously soluble in water : the solution
gradually deposits a reddish-yellow powder,
G. SuLPHABSENiATE OF Ammonium. — Terhonc Salt. — 3NH*S,A8S».—
A solution of pentasulphide of arsenic in excess of bihydrosulphate of
ammonia is gently heated and then mixed with hot alcohol and agitated.
On cooling, the salt a separates in colourless prisms, which, after being
washed with alcohol and dried by pressure, are tolerably permanent in
the air, but generally turn yellow on the surface : when oistilled, they
melt, give off a small quantity of water, and afterwards a yellow liquid,
containing sulphide of ammonium with excess of sulphur, and leave a
residue of tersulphide of arsenic.
3NH4S,AiS* » 3NH^S + 2S + AsS>.
5. BUxuic Salt, — 2NH^,AsS^. — Formed by dissolving pentasulphide
of arsenic in ammonia. The solution, when left to evaporate spon-
taneously, dries np to a thick, glutinous, reddish-yellow mass, which
cannot be perfectly dried without decomposing. Behaves like a when
distilled, the liquid which passes over containing bisulphide of am-
monium :
2NH^S,AbS* = 2(NH^S«) + AsS>.
c. Jioncbasic Salt. — NH*S, AsS^ — ^Remains in the alcoholic solution
obtained in the preparation of a.
d. With 12 atoms of acid.—NK% 12AsS'.— The aqueous solution
a or b, when boiled in a retort, evolves bihydrosulphate of ammonia,
assumes a deep reddish yellow tint, and on cookng deposits this compound
in the form of a yellow powder. (Berzelius.)
H. Ammonio-chloridb of Absenic. — Chloride of arsenic absorbs
ammoniacal gas at ordinary temperatures, evolving heat and forming
a white powder. (Persoz, Ann. Chitn. 44, 320 ; H. Rose, Pogg, 52, 62.)—
The ]>owder dissolves gradually in water, and may possibly be thereby
converted into hydrochlorate and mono-arseniate of ammonia.
4NH*,AbC1>+3HO « 3(NIP,Ha) + NH»,A«0».
But the ammonia contained in the solution is in a peculiar state of com-
bination, for it is but partially precipitated by bichloride of platinum.
(H. Rose.)— The solution, saturated while hot, yields, on evaporation,
white saline crusts, which, after careful washing, are found to contain
ammonia, chlorine, and arsenic. If the whole powder be boiled with
alcohol, the resulting solution deposits transparent cubes, which have the
same composition as the powder, but are more readily soluble in water.
Oil of vitriol withdraws the ammonia from the powder, and evolves the
chloride of arsenic. (Liebig & W&hler^ Ann* Pharm. 11, 149.)
VOL. rv. V
^90
4NH»
Am
3C1
i;80
750
106-2
ARSENIC.
.... 27-29
.... 30-09
.... 42-62
U. Rote.
24-82 ...
3116)
44-02) •
Persos.
15-92
8408
4NH»,AflCP
249-2
.... 100-00
... 100-00
.. 100-00
IT According to Pafltenr {J, Pharm. Chim. 13, 395), the white sub-
stance produced hj the action of ammonia on terchloride of arsenie^ is
composed of chlorimide of arsenic, chloride of ammonium, and ammonia :
2 (ClAsNH) + 4 (NH*C1) + NH'. When heated it first evolres ammonia,
then sublimes undecora posed, and lastly yields a sublimate consisting
chiefly of sal-ammoniac. Boiling water converts it into ammonia,
arsenioos acid, and sal-ammoniac. When treated with cold water, it
becomes heated, and evolves ammonia; and the liquid, when evaporated,
yields a precipitate consisting of small six-sided tables, containing 13*4
per cent, of chlorine, 58-1 arsenic, 5'3 nitrogen, and 2-3 hydrogen,
corresponding to the formula: ClAs'NH^O''. The formation of this
compound is expressed by the following equation : —
2(ClAgNH) + 7HO = C1A«»NH»0' + NH*C1.
When treated with strong ammonia, it is converted into neutral arsenite
of ammonia NH*0,AsO'. IT
I. Ammokio-plitoribs op Assentc.-— Fluoride of arsenic rapidly
condenses ammoniacal gas, producing white fumes, and rapidly separates
carbonic acid from carbonate of ammonia. In both cases, a white
friable mass is formed, which sublimes without decomposition. It
dissolves without decomposition in a small quantity of boiling water,
and partially crystallizes out again as the liquid cools. When a solu-
tion of this compound in a large quantity of water is evaporated in a
glass vessel, the glass is attacked, and part of the compound decomposes,
while the rest volatilizes unaltered. (Unverdorben, if. Fr. 9, 1, 24.)
3NH«
51-0
2801
71-99
Unverdorben.
27-54
AfcF«
• ■•««•«*« AOX X
72-46
3NH»,A8F9 182-1 .... 100-00 10000
Arsenic and Potassium.
A. Arsbniob oP Potassiith.— 1. Three volumes of arsenic powder
easily unite with one volume of potassium, the combination being at-
tended with vivid combustion. (Gay-Lussac & Thenard; H. Davy.)-—
Potassium heated in arseniuretted hydrogen gas, takes the arsenic to
itself, and sets free twice as much hydrogen gas as it would have evolved
from water. (Gby-Lossac & Thenard.) Hence the compound formed is
K'As. — 3. When arsenic conveys the negative electricity of a voltaic
circuit into hydrate of potash, it forms a dark ffrey metallic alloT, which,
when immersed in water, evolves arseniuretted hydrogen gas, and deposits
brown, pulverulent arsenide of hydrogen. (H. Davy, tnd. p. 264.) —
ChesUiut-brown without metallic lustre. — ^With water it evolves a quantity
of arseniuretted hydrogen gas, the volume of which is equal to half the
volume of hydrogen which the potassium contained in it would have
evolved ; solid arsenide of hydrogen is formed at the same time. (Gay-
Lussac & Thenard.)— If 100 parts (3 At.) of potassium are fused by con-
I ii
ARSENIATB Of POTASH. §91
tinned I^Hicni witli 64 ^arts (1 At.) of arsenic in tk glaafl itAe, dHtwn 6tii
to a narrow neck, and the mass treated with water, a quantity of hydrogen,
eqaal to | of that which the pure potassium would hav6 sepatated from
water, is erolved in the free state [probably because some of the potas-
sium has not combined with the arsenic]; f goes off In the form of
arseniuretted hydrogen ffas, and \ remains combined with the arsenic in
the form of solid arsenide of hydrogen. (Soubeiran, J, Pharm. 16, 95S.)
—On heating 1 part of arsenic with 3 parts of potash in solution, then
eraporating to drjmess, and heating the residue to commencing redness,
hyclrogen gas is evolred, and there remains a dark brown, tumefied masS
(containing arsenide of potaasium], which, when put into water, becomes
leated, and gives off arseniuretted hydrogen. (Gehlen.)
B. AnsteNtTB OP Potash. — Fixed Liver of Arsenic. — Arsenious acid
dissolves easily in aqueous solution of potash; from a solution of carbo-
nate ot potash it does not expel the carbonic acid until heat is applied,
and even then but slowly. — Potash-ley saturated while hot with nrseoious
acid, deposits a small quantity of that substance on cooling ; the yellowish,
strongly alkaline mother-liquid leaves a gummy residue on evaporation.
This residue, when more strongly heated^ swells up considerably, gives
off a small quantity of water, fuses tranquilly, and, if more strongly
ignited, evolves a small quantity of arsenious acid. The cooled mass
has the appearance of enamel, and dissolves very slowly in water ; even
when hot, a small portion of the arsenite of potash is found to be con-
verted into arseniate. (Simon, Fogg. 40, 442.)
Y d. Di-areenite, — 2KO,AsO'. Formed by digesting the acid salt c
with excess of potash, and precipitating with alcohol. Gives with nitrate
of silver a yellow precipitate, consisting of 2AgO,AsO'; the super-
natant liquid becomes neutral. ('Pasteur.)
6. MowhareeniU. — KO,AsO\ — Formed hj boiling c for several hours
with carbonate of potash, whereupon carbonic acid is evolved, and there
remains a salt whicn is but slightly soluble in alcohol^ and after repeated
washing with alcohol, is obtained m the form of a syrupy mass : this is
the mono-arsenite. (Pasteur.) Filhol did not succeed in obtaining this
salt in a state of purity.
c. j&t-ar«0nife.— KO,HO,2AsO'-f Aq,->-When arsenious acid in ex-
cess is digested in cold solution of potash, an oily alkaline liquid is
obtained, which does not crystallise, but, when mixed with the solution
of a silver-salty gives a yellow precipitate of neutral arsenite of silveri
mixed with free arsenious acid, while the supernatant liquid acquires an
acid reaction ; hence it follows, that the solution must contain an acid
salt. This compound is obtained by mixing the oily solution with
alcohol, whereupon it becomes thick and turbid, and after a few days
deposits on the sides of the vessel, beautiful crystals, havinff the form o^
right rectangular prisms and the composition above stated. At 100°,
they give off one atom of water. (Pasteur.) Y
C. Arbeniatb of Potash. — a. Trie^rsemaU, — 3KO,AsO*.-'^One
atom of diarseniate of potash ignited with excess of carbonate, liberates
one atom of carbonic acid. (Mitscherlich.) Aqaeens arsenic acid super-
saturated with potash, crystallizes almost wholly, on evaporation, is
small, very deliquescent'needles. (Graham, Pogg* 32, 47.)
b, Di-arseniate, — 2KO,AsO*. — Formed by adding car Donate ofpotash
to aqueous arsenic acid, as long as effervescence continues. Colourii
v2
299 ARSENIC.
Tiolet-juioe green; does not ciystaUise; fuses to a white glass wheu
heated ; deliqnesces in the air. (Schecle.)
c, Mano-arsenicUe. — KO, AsO*. — Macquer^s arsenihalisches MiUehdU*
— 1. Formed hy deflagrating eqaal parts of arsenioos acid and nitre,
dissolving the mass in vater, and leaving the solution to crystallize.
(Macquer, Olaser, Mag, Pharm, 15, 132.) — 2. By mixing aqueous carho-
nate of potash with such a quantity of arsenic acid, that the solution may
redden litmus paper, but the redness may disappear as the paper dries—
and then evaporating. (Mitscherlich.) On evaporating a mixture of
potash-ley and arsenic acid, neutral to vegetable colours, the simple salt
crystallizes out, while an alkaline bibasic salt remains in solution. Mono-
arseniate of potash crystallizes in the same forms and with exactly the
same angles as the monophosphates of potash and ammonia, and mono-
arseniate of ammonia. Fig, 23 and 30. (Mitscherlich.) More solid than
the corresponding soda-salt: of specific gravity 2*63*8; tastes like nitre.
(Thomson, Ann, Phil, 15, 85.) The redness imparted to litmus-paper by
the solution of this salt disappears on drying. (Mitscherlich.)
AnhydrouM, Mitscherlich.
KO 47-2 .... 291 .... 29-2
AsO» 115-0 .... 70*9 .... 70-6
KO,AbO* 162-2 H 100*0 Z 99^
Cryitallized, ThomBon. SGtscheilich.
KO 47-2 .... 26-19 2707) «q.qi
AsO* 1150 .... 63-82 65-43| •' ^^ ^*
2HO 18-0 .... 9-99 750 .... 10*09
KO,2HO,A«0* 180-2 .... 100-00 ~. 100*00 Z 10000
The crystals are permanent in the air, and give off bnt little water
even at 288®. At a red heat, they fuse, give off water, and are converted
into a pale yellow, very thin liquid, which, on solidifying, becomes white
and opaque and splits in all directions. (Thomson.) The crystals dis-
solve in 5*3 parts of water at 6°, forming a solution of specific gravity
1*1134; they dissolve in a much smaller quantity of hot water, but not
in alcohol. (Thomson.) The aqueous solution does not precipitate the
salts of the earthy alkalis or of the earths. (Mitscherlich.)
D. HrposuLPHAnsENiTE OP Potassium. — Terhasic Salt, — 3KS,A8S*.
Orpiment is boiled in a moderately concentrated solution of carbonate of
potash; the liquid filtered boiling hot; and the brownish red flakes of 6,
which separate from the colourless filtrate, are first washed on a filter,
with a small quantity of cold water, till they swell up like a jelly and
begin to dissolve — then treated with a larger quantity of water — and the
dark-red filtrate thus obtained, is evaporated to dryness. (That which
remains on the filter is the compound c.) — Red translucent mass. Forms
with water a yellowish-red solution — deep red in large quantity — which,
when evaporated, becomes gelatinous before it dries up. This effect is
probably due to the presence of sulpharseniate of potassium, which dis-
places the hyposulpharsenite in the water.
h, Bibasic Salt, — 2KS, AsS*. —The brown-red flakes which separate
daring the preparation of a,
e. Monobasic Salt. — KS, AsS*. — The substance left on the filter in the
preparation of a, — Dark brown powder, insoluble in water, which easily
t
ARSENIC AND POTASSIUM. 293
fuses when heated^ without giring anytliing off, and afterwards on cool-
ing, solidifies to a dark red, translucent mass. It dissolves in potash with
the same appearances as realgar. (Berzelius.)
E. SuLPHARSENiTE OP POTASSIUM. — a. Tcrlxuic Salt. — 3KS,AsS'.— *
Precipitated on mixing the aqueous solution of h with alcohol, in the form
of a syrup, which is colourless at first, but soon becomes dark brown and
deposits ^sulphide of arsenic.
6. JBibasic Salt, 2KS, As*. — Formed by heating sulpharseniate of
potassium in a retort till the excess of sulphur is evolved. Dark coloured
while fused, yellow after cooling. When treated with a small quantity
of water, it is resolved into hyposulpharsenite of potassium which is pre-
cipitated, and sulpharseniate which remains in solution.
c. Monobasic Salt. — KS, AsS'. — Formed by saturating mono- or bihy-
drosulphale of potash in the cold with orpiment. — Likewise obtained,
mixed with arsenite of potash, when orpiment is dissolved in caustic
potash or its carbonate, or when arsenic us acid is dissolved in bihydro-
sulphate of potash (p. 275). — The solution, even when evaporated at
ordinary temperatures, becomes turbid, and deposits a brown powder,
consisting of hjrposulpharsenite of potassium. When a solution satu-
rated with orpiment at ordinary temperatures, is heated with a larger
quantity of orpiment prepared in the moist way, the orpiment is converted
into realgar, and sulpharseniate of potassium is produced.
d. With excess of acid. — Formed when carbonate of potash is heated
in a retort with excess of orpiment till the portion of the latter which is
least strongly retained, is driven off. From this compound, water
extracts the compound c, and leaves a red compound, containing a still
larger excess &f orpiment and soluble in ammonia, together with hypo-
sulpharsenite of potassium which is insoluble in ammonia. (Berzelius.)
F. Sulpharseniate OF Potassium. — a. Terbasic, — 3KS, AsS*. — The
aqueous solution of &, when mixed with alcohol, becomes milky, and depo-
sits a concentrated solution of a, in the form of an oily liquid, which,
when dried at a gentle heat, leaves a fibrous, deliquescent mass.
h. Bibasic Salt.^^2KS, AsS'. — Formed by saturating aqueous diarse-
niate of potash with hydrosulphuric acid, and evaporating the liquid in
vacuo. — The residue is a viscid, yellowish, somewhat crystalline mass,
which does not dry up completely, but, when exposed to the air, first
liquefies, and then solidifies in a crystalline mass containing rhombic
tables.
c. Monobasic Salt, — KS, AsS^ — On mixing the solution of h with alco-
hol, a is precipitated and c remains in solution. The solution is decom-
posed on evaporation, and deposits crystals of octodecasulphide of arsenic.
-—2. Aqueous hydrosulphate of potash dissolves, at ordinary temperatures,
more than \ At. but less than 1 At. of pentasulphide of arsenic. The
solution, when evaporated in the air, first becomes covered with a film
of sulphur, then deposits a red crust, and by this loss of sulphide of
arsenic, is converted into the bibasic compound 6, which dries up first to a
stiff syrup and then to a lemon-yellow mass. (Berzelius.)
d. With 12 atoms of acid. — KS,12AsS*. — Precipitated when the solu-
tion of b is decomposed by carbonic acid ; similarly on passing hydrosul-
phuric acid gas through mono-arseniate of potash. — Yellow powder, con-
taining 2*9 snlphide of potassium to 97*1 pentasulphide of arsenic
(BerzeliQs.)
894 ABSBNIC.
IT O. SuLPHoxiARSRNiATE OF Potash. KOyAsCS'+HO. For the
preparation of this salt, see pa^e 280. Crystallizes in small, white, elong-
ated prisms, sometimes 1 or 2 centimetres in length; slightly soluble in
water. The dry salt is permanent in the air; gives up all its water at
170^ without melting. Fuses over the spirit-lwDup; giving off first aisenic
sulphide and then metallio arsenic.
CrysMHtBd. Bouquet Si Cloei.
fAi 750 .... 38-26 88-02
h% 820 .... 16-37 16-10
|30 240 .... 12-21 12-43
KO 47-2 .... 2401 23-69
2H0 18-0 .... 915 9-50
KO, AflOSS* + 2 Aq 196-2 .... 10000 IZ! 9974
The aqueous solution decomposes rapidly at a boiling heat^ giving off
hydrosulphuric acid and depositing sulphur. If hydrochloric acid be then
added^ a precipitate of sulphide of arsenic is obtained. From the salt
itself, hydrochloric acid precipitates nothing but sulphur, and the preci-
pitation is complete; the filtrate then contains arsenious acid. Lead-salts
added to the solution give a white precipitate, which soon turns black.
(Bouquet & Cloez, N. Ann. Chim. PKys, 13^ 44; abstr. Ann. Pharm, 56,
216.) f.
H. Arsenitb of Iodide of Potassittm. — Precipitated on mixing the
aaueous solutions of iodide of potassium and arsenious acid, or of iodide
01 potassium and arson ite of potash. In the former case, the arsenious
acid is completely precipitated; in the latter, part of it remains dissolved
in combination with excess of potash. If arsenite of potash (obtained by
boiling arsenious acid with aqueous solution of caustic potash and leaving
the solution to cool) be mixed with such a quantity of acetic acid, that
the solution shall no longer redden turmeric paper — and iodide of potskssium
be then added — a quantity of arsenious acid is precipitated sufficient to
restore the alkaline reaction. After washing with cold water and dryings
the compound is obtained in the form of a white powder :
CalcttlatioB. Emmet.
KI 165-2 .... 85-77 36-7
3AaO> 2970 .... 64-23 633
KI,3AsO* 462-2 .... 10000 100-0
The compound is decomposed at 315% evolving large quantities of
arsenio vapfiur, and afterwards at a higher temperatprei giving off iodine :
the loss amounts to 81 per cent. The residue, when treated with oil of
vitriol, acquires a deep prown tint, from separation of iodine and iodide
of srsenic. The unignited compoon4 acquires a black-brown tint by oon-
taot with strong nitric acid and heated oil of vitriol, and bright yellow
witli C0I4 oil of vitriol. It dissolves in 1 9 parts of boiling water, (Enunetj
SUl. Am^. </. ] 8^ 58.)
AbSBHIO AKD SODIITM.
A. Absenidb of Sodium. — a. Three volumes of arsenic powder
unite below a red heat with one volume of sodium, emitting a hint light
and forming a brittle; fine-grained mass, which oxidates quickly in the fiir.
and when thrown into water produces arseniuretted hydrogen gas ana
ARSENIATS OF SODA. 295
solid arsenide of hydrogen. — 5. One volume of arsenic prodaces with
2 volumes of sodium an earthy chestnut-brown compound, without metallic
lustre, which exhibits the same reactions. The same brown compound is
likewise formed by heating sodium in arseniuretted hydrogen gas. (Gay-
Lussac & Thenard.)
B. Arsbnite op Soda, — Viscid, yellow, foul-smelling liquid, from
which, when concentrated to the consistence of a syrup, provided it
contains excess of soda, small f^rains are deposited. IT According to
Pasteur, arsenious acid forms with soda three salts, exactly corresponding
in composition to the arsenites of potash (p. 291); but the acid salt,
NaO,2AsO^ refuses to crystallize. %
C. Arsbniate of Soda. — Tris-^rseniaU. — One atom of di-arseniate
of soda ignited with excess of carbonate of soda, drives out one atom of
carbonic acid. (Mitscherlich.) — If to a concentrated solution of the bibasic
salt 6, there be added at least half as much carbonate as it already con-
tains (the liquid should feel soapy), and the solution be then evaporated
to dryness, the hydrated salt separates almost completely, while the
mother-liquid retains scarcely anything but the excess of soda. The
crystals are purified by rapid drying between blotting-paper, solution in
twice their weight of hot water, and crystallization.— -Bight rhombic
prisms, truncated at the acute lateral edges (Jig, 70°). Taste strongly
alkaline. In the dry state, they are permanent in the air; they fuse at
85•5^ (Graham.)
At. Anhpdnmi» At. CrygttilHztd, Graham.
NaO 3 .... 93-6 .... 44-87 .... 3 03-6 .... 22*04 .... 22'85
AaO* I .... 115-0 .... 55-13 .... 1 1150 .... 2709 .... 27-76
HO .... .... 24 216-0 «.. 50-87 .... 50-22
3NaO,ABO» 1 .... 208-6 .... 10000 +24Aq. 4246 .... 100-00 .... 100-83
The crystals, when ignited alone in a platinum flask, lose 49*7^ per oeni
of water; and if afterwards ignited with arsenious acid, mono-arseniate
of soda, or bichromate of potaeh, they give off 0*47 per cent, more.
Also, when the ignited salt is finely pounded, and then again ignited, it
gives off nearly all its water. The ignited residue does not fuse, even at
a white heat ; it attacks glass like caustic soda. When it is ignited in
the air, the residue greedily absorbs carbonic acid, whereby the 0*47 per
cent, of residual water is expelled. In a similar manner, this residual
water is expelled by ignition with carbonate of ammonia, the 0*47 -per
cent of water being replaced by 1*055 per cent, of carbonic acid, and
the hydrate of soda, which may be supposed to exist in the ignited
residue, being thereby converted into carbonate. The carbonic acid thus
absorbed is not expelled, ev^en at a white heat. [This retention of
0*47 per cent, of water might be easily explained, by supposing that the
salt contained more than 3 atoms of soda to 1 atom of acid, and that the
excess of soda was present in the form of hydrate; Graham, however,
maintains that the salt which he used was so pure, as to render such a
mode of explanation inadmissible.] — The aqueous solution of the salt
attracts carbonic acid from the air, and is thereby converted into
diarseniate of soda. A similar action is produced by other weak acids,
also by chlorine and iodine, and by nitrate of ammonia, from which
ammonia is given off. — The salt dissolves in 3*57 parts of water at 15^*5
(Graham; Pogg. 32, 33.)
296 ARSENIC.
5. Z>i-ar«tfnui/d.— Formed by adding carbonate of soda to aqueoas
arsenic acid, till the liqaid acquires a strong alkaline reaction, then
evaporating, and leaving the solution to crystallize. The crystals when
ignited leave the anhydrous salt, which is a white mass, having an
alkaline reaction, and easily fusing to a transparent and colourless liquid.
The salt remains liquid for a long time sJter fusion, but ultimately
solidifies in a fibrous mass, having a silky lustre. (Marx.) When ienited
in a current of hydrogen gas, it evolves arsenic and is converted into
hydrate of soda. (Soubeiran.) No modification analogous to pyrophos-
phate of soda can be obtained by ignition. (Clark.)
JgniUd,
62-4
115-0
3518
64-82
Mitacherlidi.
34-16
AaO»
65-84
2NaO,A80* ...
177-4
100-00
.... 100-00
On crystallinng from the aqueous solution, the salt takes up 15 atoms
of water into its crystals, if the solution be warm and concentrated, and
25 atoms if it be cold and dilute.
«. WUh 15 otoifwo/ water.— 2NaO,HO,AsO»+14Aq.— Crystalline
system the oblique prismatic. Fig. 108, with the /-face; i : £=97°;
% : a=123« 22': i : f, 6«^tW=128° 27'; * : M=d4° 26'; % : A, behind
= 116^ 42'; u : tt'=78° 46'; z :z:=z\lT 1&; «:/=134*» 33'.—
Cleavage parallel to if, (Haidinger, Edivh. J. of Sc. 7, 314; compare
Marx, Kastn. Arch. 2, 18; Bemhardi, i^. Tr. 11, 1, 10; L. Gmdin,
Pogg. 4, 157.) — The crystals do not effloresce even in warm air. At a
heat below redness they give off 41-18 per cent. (14 At.) of water; after-
wards, at a red heat, 2*96 per cent. (1 At.), and leave 55'86 per cent, of
anhydrous salt. (Churk, Edinh. J. of Sc. 7, 309 ; also Schw. 57, 437, and
440; abstr. Pogg, 16, 609.)
0. WUh 25 atOTM of tcorf^-.— 2NaO,HO,AsO»+ 24 Aq.— Crystalline
form exactly like that of diphosphate of soda with 25 At. water, described
at page 92, Vol. III. (Mitscherlich); Fig, 96, 97, 98, 99, 100. The crystals
effloresce very quickly in the air, even at 9% and are converted into the
salt «. (Clart.)— They dissolve very readily in water.
NaO
AsO* ....
HO
At.
2
1
15
• «••
■ •«•
Salt a.
62-4 .... 19-981
115-0 .... 36-81J
135-0 .... 43-21
Clark.
55-86
4414
Gmdin.
56
44
NaO.
AbO<
HO .
1
■••■•■•
• •«•
•»■• •••1
312-4
Ac.
k X ••••
20 »•..
.... 100-00
Salt p.
62-4 ....
115-0 ....
225-0 ....
15-511
28-58 '
55-91
100-00
Mitscher]
44-19
55-81
100
iich.
X ••••
402-4 ....
100-00
10000
c.^ Mono-arsenicUe, — Formed by adding arsenic acid to an aqueous
solution of carbonate of soda, till the liquid no longer precipitates chlo-
ride of barium, then evaoorating, and leaving the couceiitrated solution
for some time in a cold place. — Large crystals, precisely similar in form
and in the magnitude of their angles, to those of phosphate of soda
when that salt is crystallized by method 2, page 93, Vol. III. (Fig. 94).
More soluble in water than b, (Mitscherlich.)— From a solution of soda
ARSENIC AND SODIUM. 297
and arsenic acid^ mixed in such proportions as to be neutral to vegetable
colours, di-arseuiate of soda crystallizes first, and then the liquid shows
an acid reaction. If to an aqueous solution of 3 atoms of di-arseniate of
soda, there be added 2 atoms of sulphuric acid, the liquid immediately
begins to redden litmus^ but still colours turmeric brown. (Mitscherlich.)
The result is a mixture of 4 atoms of soda and 3 atoms arsenic acid.
3(2NaO, A«0*) + 2S0» = 2(NaO, SO») + 4NaO, SAsO*.
This salt is not converted by ignition into a modification analogous to
metaphosphate of soda. (Graham.)
Ignited, Mitscherlich. CryttoUiztd, Mitscherlich.
NsO 31-2 .... 21-34 .... 21-68 NsO.... 31-2 .... 17-12 .... 17-36
AsO« 115-0 .... 78-66 .... 78*32 AsO* 115-0 .... 63-12 .... 62-70
4HO 36-0 .... 19-76 .... 1994
NaO^AsO* 146-2 .... 100-00 .... 100-00 +4Aq. 1822 .... 100*00 .... 10000
D. HyposuLPHARfiENiTE OF SoDiUM. — The terbasic, bibasic, and
monobasic salts are precisely similar to the corresponding potassium
compounds. (Berzelius.)
E. SuLPHARSENiTE OF SoBiUM. — Analogous^ to the potassium com-
pound. (Berzelius.)
F. SuLPHARSENiATE OP SoDiUM. — a. Terhasus Salt. — 3NaS,A6S'. —
a. Anhydroui, — The compound heated without access of air^ fuses
quietly after having parted with its water, and forms^ without decompo-
sition, an oily liquid, which on cooling yields a solid yellow mass. This
substance, when immersed in water, is first converted into the crystalline
compound /3, and then dissolves.
/9. Hydratedy crystallized, — 1. Prepared by precipitating a solution of
5 with alcohol. — 2. By leaving a mixture of h and bi-hydrosulphate of
soda to spontaneous evaporation. — 3. By digesting the alcoholic solution
of pentasulphide of sodium with orpiment, pouring the liquid ofi^,
washing the residue with alcohol, then dissolving out the terbasic salt
with water, and leaving the solution to crystallize.-— 4. By dissolving
pentasulphide of arsenic in aqueous solution of soda, and leaving the liquid
to crystallize. The crystals obtained by either of these methods are
washed on a filter with alcohol, then pressed out and dried. (Berzelius.)
—5. By boiling 1 part of sulphur, li of orpiment, and 8 of ciystallized
carbonate of soda with water, and purifying the crystals obtained from
the filtrate by recrystallization. (Ranimelsberg, Fogg. 52, 238.) — By
method (1): snow-white crystals; by (4): ill-defined rhomboidal tables.
Crystallizes by slow cooling from a hot aqueous solution in irregular six-
sided prisms, with two of their lateral edges more acute than the rest.
By spontaneous evaporation or very slow cooling, it crystallizes in trans-
parent rhombic prisms with dihedral summits resting on the acuter
lateral edges; and by still slower cooling, till the temperature falls below
0^, in white, opaque, rhombic octohedrons. (Berzelius.) — Oblique rhombic
prisms, Jig, 85, together with m-faces; u' : ^=113° 40'; * \m (or :the
axis) = 120°; f:m-=r 103® 20'. (Rammelsberff.) — The opaque crystals are
milk-white;' the transparent crystals are yellowish^ and have someif hat
of a diamond lustre. (Berzelius.)
298 ilRSENIC.
CryttalHztd* Or: Benetint. RammelBberg.
8N».... 69-6 .... 17-08 3Na8.... 117-6 .... 28-85 .... 28-47 .... 2852
Km .... 75-0 .... 18-40 AsS* .... 155-0 .... 3803 .... 88-OS .... 87-32
8S .... 1280 .... 31*40 15H0 1350 .... 33-12 .... 3350 .... 84*16
15H0 1350 .... 3312
407*6 .... 10000 407-6 .... 10000 .... 100-00 .... 100-00
In the dry state^ it is permanent in the air ; even in yacno over oil of
vitriol^ it does not give np its water till ^ntly heated; it then hecomes
milk-white J when more itrongly heatedj it givea off a small quantity of
hydrosulphuric acid^ and turns yellow. Heated in a retort, it liises in
its water of crystallization^ forming a yery pale yellow liquid, — then
giyee off water, and is conyerted into a white salt, which, when more
strongly heated, decrepitates slightly, eyolyes the remaining water and a
small quantity of hydrosulphuric acid, and fuses to a dark red liquid ;
on cooling, this liquid soliaifies and forms the yellow anhydrous com-
pound a. (Berzelius.) — Decomposed completely by boiling with sulphate
of copper, yielding a precipitate of sulphide of copper, while soda,
sniphurio acid^ and arsenic acid remain in eolation.
3NaS,AsS» + 8(CuO,SO») = 8CuS + 3NaO + A«0» + 8S0«.
A similar decomposition takes place with acetate of lead ; but the
precipitated sulphide of lead [if the acetate is in excess], is mixed with
arseniate of lead, because that salt is insoluble in acetic aoid. (Rammele«
berg.) — The salt dissolves easily and abundantly in water. (Berzelius.)
h, Di-add SaU. — 2NaS, AsS'. >- The aqueous solution of di-arseniate
of soda, saturated with hydrosulphuric acid gas, and then left to eyapo-
rate spontaneously, yields a yisoid liquid, and afterwards, if gently
heated, a dry lemon-yellow mass. This substance fuses at a moderate
heat, forming a yery pale yellow liquid (losing water at the same time if
warmed in an open vessel), and on cooling, solidifies in a yellow mass^
whioh softens when exposed to the air. (Berselius.)
0. Mondbiwio SaU. — NaS,A86*. — When the hydrated compound a,
fi, is prepared with alcohol acoording to method (1), the supernatant
alcoholic solution contains the mon<H>afiic salt. On distilling off the
alcohol, the liquid often deposits octodeca-snlphide of arsenic in beautifiil
crystals.
d. With 19 atoms of a<»el.^Nafi,l 8 AsS^ ^Obtained like the potas*
sinm compound. Yellow powder. (Berzelius.)
G. Arsbkiatb op Soda and AMM0NiA.^An aqueons aolntion of
eqnal parts of di-arseniate of soda and di-arseniate of ammonia yields
crystals, whose form exactly agrees with that of phosphate of soda and
ammonia (III.| 118. Fig. 101, 102); these crystals, when heated to
redness, yield mono^areeniate of soda.
CryitdUiged, Mitscherlich.
NH» 17*0 .... 6-71 +HO 4304
NftO 31*2 .... 12-321 -^.^
A«0» 115*0 .... 45*42/ ^ *'* ^
lOHO 90*0 .... 35*55
NH«O.NaO,UO,AsO* + 8Aq. 253*2 .... 100*00 100*00
H. SULPHARSENIATB OP SoDIUM AND AmMONIUM.— ^tfrfcoWC.
(3NH*S,AsS*) + (3NaS,AsS0.— 1. Formed by adding warm alcohol to
ARSENIC AND LITHIUM. 299
a miztnre of the aoaeous solQtions of disalpharseniate of ammoniam and
disnlpharseniate of sodiunii and agitating the mixture. As the liquid
cools, small four-sided tables crystallize out. — 2. When a solution of
trisulpharseniate of sodium in a small quantity of cold water is mixed
with sal-ammoniac, and the liquid abandoned to spontaneous evaporation,
the double salt crystallize out in six-sided prisms, perpendicularly trun-
cated, and haying two of their lateral faces broader than the rest.—
The crystals are transparent, and either colourless or pale-yellow : they
are permanent in the air. When distilled^ they snye off hydrosulphate
of ammonia with a small quantity of water, and leave sulpharseniate
of sodium. The double salt dissolves in water much more readily than
the sodium salt alone. (Berzelius.) The aqueous mixture of disnlphar-
seniate of ammonium and disnlpharseniate of sodium, when evaporated
without the addition of alcohol, leaves a dry yellow mass, having none
of the characters of a double salt. (Berzelius.)
I. Arseniate of Soda and Potash. — Formed by neutraliaing the
aqneons solution of mono-araeniate of potash with carbonate of soda.
The oryatals exactly resemble those of the phosphate of aoda and potash.
(Mitacherlich, III. 119.) Fig, 107, 108. [Since these crystals appear
to be isomorphoua with those of diaraeniate of soda with 1 5 atoms of
water (p. 296), a question arises aa to whether the crystals of the double
phosphate and double arseniate of soda and potash op not also contain
merely 15 atoms of water instead of 17. The formula is then the aamej
viz. KO,NaO,HO,AsO'-hl4Aq, excepting that lAt. NaO is replaced by
lAt. KO.]
Anhydrou9, CrytiaUixtd. Kitscherlich.
KO 47-2 .... 24-41 KO 47*2 .... 13-631
NftO .... 81-fi .... 16-18 N»0 .... 31-2 .... 9-01 > 66-12
AsO* .... 115-0 .... 59*46 AiO* .... 115*0 .... 33*20 J
17Aq 153*0 .... 44*16 43*88
193*4 .... 100*00 846-4 .... 10000 ZZ. 10000
K. SuLPHABauriATB OF Sodium and PoTAaanrsf. — Terboiic 8aU,^^
Fonned by mixing the aqneona aolutiona of the aulpharaeniatea of aodlnm
and potaaainm, and oryatalliainff. Tnuiaparent and oolourleaa, or pala
yellow^ fonr-sided tahlea. (Beraeliaa.)
Abbbnio and Lithiux.
A. SuLPHARSENiTB OF LiTHiux. Behaves like the corresponding
pompounds of potassium and sodium. (Berxelina.)
B. SuLPHARSBNiATE OF LiTHiUM. — a. Terbosic Salt, — Precipitated
from the aqueous solution b, by the addition of alcohol^ in large, colourless,
shining, crystalline scales. When this precipitate is dissolved in hot
water and the eolation quickly cooled, the aalt separates in six-sided
prisms; by spontaneous evaporation, on the contrary, rhombic prisma are
formed. These crystals are easily soluble in water; they behave like the
Gorreaponding sodium compound both during and after ignition, and must
therefore contain water.
b. Bihasic. — The aqneons solution yielda by evaporation a non-
erystalline, lemon-yellow mass, which does not become moist in the air,
and redi88olvea peirfeotly in water.
300 ARSENIC.
c, Monobctsic, — d. With 12 atoms of acid. — Both these Balis behave
like the correspondiog sodium compoands.
Absenic and Barium.
A. Arsenite of Baryta. — ^Aqueous arsenioiis acid when largely
dilated, does not precipitate baryta-water in any proportion; when the
liquid is somewhat more concentrated and the baryta more in excess, a
precipitate is formed after a while; and when the strength of the solution
and the excess of baryta are still greater, precipitation takes place imme-
diately. (Gm.) Arsenite of ammonia gives a precipitate with chloride
of barium, but not till after some time. (H. Rose.)
IT a. Di-arseniie, — 2BaO,A60'. — Formed by precipitatinfi; chloride of
barium with di-arsenite of potash. Resembles b in external characters.
Slightly soluble in water. (Filhol.)
b. Mono-arsenile. — BaO,AsO'. — Precipitated, on mixinj? chloride of
barium with mono-arsenite of potash or soda, in the form of a gelatinous
magma, or in|dendritic ramifications, which however show no sign of
regular crystallization. The gelatinous mass is easily soluble in water,
but after ^ying forms a white insoluble powder. On filtering the liquid
from the gelatinous precipitate and boiling it, a heavy white powder
having the same composition is precipitated. (Filhol.) IT
B. Arsbniate of Bartta. — Tris-arseniate, — By digesting b with
aqueous ammonia. (Berzelius.) — 2. By precipitating arsenious acid with
excess of baryta-water. (Laugier). — 3. Bj gradually dropping tris-arseniate
of soda into chloride of barium — whereby a heavy powder is quickly
formed — and rapidly washing the precipitate, so that it may not absorb
moisture from the air. If, on tne other hand, chloride of barium in
solution be gradually added to an excess of tris-arseniate of soda, a gela-
tinous precipitate is obtained, which becomes finely flocculent on boiling :
but the liquid is strongly alkaline, a proof that di-arseniate of baryta has
been thrown down together with the tris-arseniate. The precipitate likewise
carries with it a small quantity of tris-arseniate of soda, which cannot be
completely extracted by washing. (Graham, Po^(7. 82, 48.) Tris-arseniate
of baryta is a white powder which attracts a small quantity of carbonic
acid from the air. About 0*8 per cent, of carbonate of baryta may be
formed by igniting the tris-arseniate in the air. (Graham.) Dissolves
readily in cold hydrochloric, nitric, tartaric, and acetic acid (Anthon);
very slightly soluble in water, somewhat more soluble in aqueous ammo-
nia (Berzelms); its solubility in water does not seem to be increased by
the presence of ammonia, potash, or soda salts. (Laugier.)
Ignited, Laugier. Beneliiu. Graham.
SBaO 229'8 .... 66-65 .... 65'7 .... 66*56 .... 67'94
AsO* 115'0 .... 33-35 .... 34*3 .... 33-44 .... 32-06
3BaO> AsO« 344-8 .... 100-00 Z 1000 Z. 10000 Z lOO'OO
b. Di-arseniate. — When di-arseuiate of soda is mixed with excess of
chloride of barium, this salt is precipitated, after a few seconds, in small,
white, crystalline scales. (Berzelius.) The quantity of arseniate* of soda
must be less than sufficient to decompose the whole of the chloride of
barium, and it must be added drop by drop; the first portions pf preci-
ARSENIC AND BARIUM.
301
pitate disappear again [is then arseniate of baryta soluble to a certain
extent in cnloride of barium?] If, on the contrary, chloride of barium be
gradually added to di-arseniate of soda, a precipitate is formed consisting
of di-arseniate and tris-arseniate of baryta together, while mono-arseniate
of baryta remains in solution. (Berzelius, Mitscherlich.) According to
Scheele, free arsenic acid does not precipitate hydrochlorate, nitrate, or
acetate of baryta. According to the author's experiments, it precipitates
the acetate if not the other salts; according to Maretti, it gives a precipi*
tate even with acid sulphate of baryta [due to the presence of water],
and arseniate of baryta is not decomposed by sulphuric acid; the author^
however, found that it is decomposed by digestion with dilute sulphuric
acid. When ignited, it merely gives up its water of crystallization. By
contact with water, it is resolved into the salt c which dissolves, and
the salt a which remains behind. (Berzelius.)
2BaO
AsO*.
Ignited.
153-2 .... 57-12
1150 .... 42-88
BerselivB.
57*06
42*94
2B80,A80*
268-2
100-00
2BaO
AsO*.
4H0.
OyHallized.
153-2 .... 50-36
115-0 .... 37-80
36-0 .... 11-84
100-00
Berzelius.
50-32
37-86
11-82
+ 4Aq.
304-2
100-00
100-00
c Mono-uneniate, — 1. Formed by adding baryta-water to aqueous
arsenic acid, as long as a precipitate continues to form. — 2. By dissolving
h in aqueous arsenic acid and leaving the solution to crystallize. Mono-*
arseniate of soda does not precipitate chloride of barium, but on adding
the smallest quantity of ammonia, a precipitate is formed. The crystal^
contain water of crystallization, and are soluble in water.
BaO
AsO*
Ignited.
76-6 .... 39-98
115-0 .... 6002
Mitscherlich.
40-13
59-87
BaCAsO* 191-6
100-00
10000
C. Hyposulpharsenite of Barium. — Precipitated when an aqueous
solution of the terbasic potassium-salt D (p. 292) is mixed with chloride
of barium. Red-brown powder, insoluble in water. (Berzelius.)
D. SuLPHARSBNiTE OP Barium. — a. Terbcuic Salt. — 1. Formed by
precipitating the aqueous solution of 6 with alcohol. — 2. By digesting
orpiment with excess of sulphide of barium and water. When prepared
by the first method, it separates in scales. Dissolves with difficulty in
water, and, when the solution is left to evaporate spontaneously, it is
again deposited in delicate white scales, with which very small trans-
parent ciystals of sulphate of baryta are mixed.
h. Bihasic Salt. — The nearly colourless aqueous solution dries up to a
gummy mass, which when perfectly dry, exhibits a fine red-brown colour
and redissolves completely in water, (berzelius.)
E. SuLPHARSENiATB OP Barium. — a. Ter^^asic Salt. — 1. Formed
when the salt b is heated to redness in a retort; sulphur and orpimen^
309 ARSBKIC.
then sublime, and there ranaiiiB ft fased maes which Msiiinec a htowh
colour on cooling. This substance dissolres in water, with the exception
of a small quantity of brown matter, and the solution dries up to a
crystalline, lemon-yellow mass. — 2. By mixing b with sulphide of oarium
dissolred in water. This mixture, if cooled down to the freezing point in
vacuo oyer oil of ritriol, and then left in the racuum till tne ice is
eraporated, leares the salt a in loose, transparent, non-crystalline scales.
— 3. On mixing the aqueous solution of 6 with alcohol, a white cnrdy
substance is precipitated, easily soluble in water, and probably consisting
of the same compound, but in the hydrated state.
6. Bibasie Salt, — The aqueous solution dries up to a fissured, lemon-
yellow mass, which, if exposed to the air after all its water has been
driven off, absorbs water again, swelling up and falling to pieces at the
same time; it is soluble in water in all proportions. Sulphate of potash
added to the solution throws down sulphate of baryta, while the corre-
sponding potassium compound remains in solution.
c. Monobasic Salt. — Left in solution when b is precipitated by alcohol.
The solution when evaporated deposits a and is thereby converted into 6.
d. With 12 aiams of acid» — Yellow powder, which is decomposed by
acids with evolution of sulphuretted hydrogen, and is not soluble in water.
ArSBKIO and STRONTIUMt
A. Arsenitb of Strontia. — Saturated strontia-water is not precipi-
tated by aqueous arsenions add in any proportion, not oven on ooiling.
(Gmelin.) Arsenite of potash precipitates chloride of strontium, but not
till i^ter some days, and more slowly than chloride of barium. (H. Rose.)
B. Arsbniatb op Stroktia. — a. Di-arseniaU. — Formed by mixing
strontia-water with a slight excess of arsenic acid, or chloride of strontium
with di-arseniate of soda. Chloride of strontium is not precipitated by
arsenic acid. White powder, insoluble in water.
6. MoTUharseniate? — The salt a is easily soluble in aqneous arsenic
acid.
C. Htposulpharsenite of Strontitm.— Analogous to the barium
compound. (Berzelius.)
D. SuLPHARSENiATE OF SxRONTitTM. — a, Iterbosie Salt. — Formed by
precipitating b with alcohol. The precipitate sometimes forms a syrup,
sometimes a white powder, accordingly as it is more or less purified from
b) it dissolves easily in water.
b. JDi^acid Salt. — Analogous to the barium compound. (Berselius.)
ArSBKIO AND CaUUVM.
A. Arsenite of LtMS. — a. Di-arienite. — Precipitated in flakes on
mixing aqueous arsenious acid with excess of lime-water, or arsenite of
ammonia with hydrochlorate or sulphate of lime. To obtain it pure, a
bottle is completely filled with the mixture of arsenious acid and excess
of lime-water, and then closed; afterwards the liquid decanted — the bottle
filled up with water-— the liquid decanted again^ and so on, several times;
ARSBNITB or LIME. 303
tbe precipitate is then collected on a filter — ^washed with a small quantity
of water — and afterwards *perfectly dried and preserved in a well-stopped
bottle to prevent it from absorbing carbonic acid from the air. (Fr.
Simon, Pagg, 40, 117.) White, heavy, coherent, powder.
Dehydrated,
2CaO 56 .... 36-13 37-7
AsO* 99 .... 63-87 62-3
2CaO«A«0> ...
2CftO
AbO"
HO
155 .... 100*00
Dried in the air,
56-0 34*14
99-0 60-37
9-0 5-49
... 1000
Simon.
34-d
57-5
7-7
2CaO,HO,ABO» .... 1640 10000 1000
Simon's analysis ^ves ^ At. water mote; it is possible, however, that
the salt, after drying m the air, may have had hygroscopic water adhering
to it.
The salt| when heated to redness, gives off arsenic and is converted into
arseniate of lime. For the complete decomposition of the arsenite of
lime, long continued ignition is necessary; and the process succeeds better
in the open air than in closed vessels. (Simon.) The salt attracts carbonic
acid from the air. When it is mixed with solution of carbonate or phos-
phate of ammonia, potash, or soda^ double decomposition takes place, the
products being carbonate or phosphate of lime and soluble arsenite of
ammonia, potash, or soda. In carbonate of ammonia it dissolves at first,
but the solution soon becomes turbid. (Wittstein.) It dissolves readily
in sulphate, hydrochlorate, nitrate, and acetate of ammonia (Gieseke &
Schweigger, JSchw. 43, 359); also in succinate of ammonia (Wittstein);
also in arsenite of ammonia, if the latter does not contain too great an
excess of alkali. (Schweigger.^ The act of solution in heated ammoniacal
salts is attended with evolution of ammonia. (Wach.) If freshly preci-
pitated arsenite of lime in excess be digested in a concentrated solution of
sal-ammoniac, a filtrate is obtained which yields no crystals even on the
addition of alcohol, but when evaporated m the air, leaves a deliquescent
residue of chloride of calcium and arsenite of lime with exoess of arsenions
acid. Similarly, arsenite of lime, when digested in arsenite of ammonia^
forms a solution which is not precipitated by alcohol, but on evaporation
yields acid arsenite of lime which is soluble in water. (Wach, Schtp. 59,
272.) After drying, the arsenite of lime is less easily soluble in ammo-
niacal salts, but regains its original solubility on boiling. (Gieseke.) Di-
arsenite of lime is very sparingly soluble in pure water; about 3000 or
4000 parts of chloride of potassium or sodium dissolved in the water
slightly increase the solubility. It dissolves readily in acids, even when
weak and dilute.
(. Mono-arseniie, — A solution of chloride of calcium is mixed with
aqueous ammonia saturated as mucb as possible with arsenions acid while
hot; more ammonia is then added, whereby the precipitate is increased;
and the precipitate is finally washed upon a filter. A considerable
quantity dissolves during the washing. The precipitate when dry is
lighter than a. When strongly ignited in the air, it gives off more than
22 per cent, of arsenio* It is somewhat soluble in water. (Simon, Pogg,
40, 417.)
304 ARSENIC.
Dehydrated kg heatm Sinuni.
C«0 28 .... 22*05 21*47
AsO* 99 .... 77*95 .... 78*53
CaO,A>0> ....
127
*■■•
100*00
••■*
100-00
Ihried in a current qfmr»
Simon.
2CaO
56
•■«■
21*29
• •••
20-74
2A80»
198
*•••
75*29
»•••
75*86
HO
9
■■«•
3*42
• ••■
3*40
+ 4Aq. 263 .... 10000 .... 10000
c. Acid Salt. — Formed by dissolyiug a or 5 in arseniouB acid« Lime-
water gives no precipitate with excess of araenions acid.
B. Arsbniate of Lime. — a, Trii^neniate. — 1. Precipitated on
mixing chloride of calcium with di-arseniate of ammonia^ potash, or soda,
the sapematant liquid acquiring an acid re-action. TMitscherlich.) The
supernatant liquid becomes slightly turbid on the aadition of ammonia.
(Wach.) — 2. Precipitated on mixing chloride of calcium with tris-
arseniate of soda. If the quantity of soda-salt added be insufficient to
precipitate the whole of the lime-salt, the precipitate obtained is compa-
ratively purer and less gelatinous : if, on the contrary, the lime-salt be
added to an excess of arseniate of soda, the precipitate has a more gelatinous
consistence, because it carries down with it a portion of the arseniate of
soda. (Graham, Pogg. 32, 49.) The salt is decomposed when ignited
alone : when i^ited with sulphuric acid, it does not give up the whole of
its arsenic acid. (Simon.)
b. JDi-arseniate. — Found native in the hydrated state, as Pharmacolite
and HaidingcriU. Precipitated on mixing arsenic acid with lime-water
in suchproportion that the liquid may still contain a quantity of acid
salt. Haidingcrite is found in cr3rstal8 belonging to the right prismatic
system, and of specific mvity 2*848. (Haidinger, Pogg. 5, 181.) Phar-
macolite occurs in capillary crystals — ^rarely in large crystals — ^belonging
to the right prismatic system, and of specific gravity 2*73. Artificially
prepared di-arseniate of lime is a white powder. The salt is not decom-
posed by heat, however intense. When digested in oxalate of ammonia,
it is converted into oxalate of lime. (Laugier.) Insoluble in water;
dissolves in hydrochloric and nitric acid, and likewise in aqueous sulphate,
hydrocblorate, nitrate, and acetate of ammonia. (Pfaff, Schw. 45, 100.)
The quantity dissolved by ammoniacal salts at ordinary temperatures is
but slight) and the solution, after a while, deposits crystals of arseniate of
lime and ammonia; but on boiling, the arseniate of lime is permanently
dissolved, with evolution of ammonia. (Wach.) Vid. Formation of
Arseniate of Lime and Ammonia (p. 306).
2CaO
AiO«
••■■•••
At.
2
1
3
Ignited. Artificial.
56 .... 32-75
115 .... 67*25
171 .... 100*00
Haidingcrite.
56 .... 28*28)
.... 115 .... 58*081
27 .... 13-64
Laugier.
32*5
67*5
2CaO,A80»
CaO
AiO*
HO
100*0
Turner.
85*68
14*32
1
.... 198 .... 100*00
10000
i
ARSENIC AND CALCIUM. 305
At. PhttrmacoHte. Rammelsberg. Klaproth.
CaO 2 .... 56 .... 24-89 .... 23-59 .... 25-00
AsO* 1 .... 115 .... 5111 .... 51-58 .... 5054
HO 6 .... 54 .... 24-00 .... 23-40 .... 2446
CuOandFc20» .... .... .... 143
1 .... 225 .... 100-00 .... 10000 .... 10000
The Pkarmacolite of Gliicksbrana analyzed by Rammelsberg is mixed
with cobalt-bloom.
c. Mono-anenicUe, — a and b are soluble in aqueous arsenic acid; the
solution yields small crystals on evaporation.
C. Hyposulpuarsenitb op Calcium. — Red-brown powder, insoluble
in water. (Berzelius.)
D. SuLPHARSENiTE OF Calcium. — a. Terbasic Salt. — When a solution
of sulphide of calcium in the aqueous solution of 5 is mixed with alcohol,
this salt is precipitated in the form of a white crystalline substance, while
the compound h remains dissolved in the liquid. (Berzelius.) Voigt and
Gottling {Taickevb, 1781, 49), by boiling 1 part of lime and 2 parts of
oipiment with water, and setting the filtrate aside, obtained long needles
which had a caustic taste. These crystals, when ignited, diminished in
weight by 25 per cent., and became white and opaque without fusing;
when treated with acids, they evolved sulphuretted hydrogen and yielded
a precipitate of orpiment; they were soluble in water, but not in alcohol.
Crysiallized. Or: Berzelius.
3Ca 60 .... 16-40 3CaS 108 .... 29*51 .... 29-80
Ab 75 .... 20-49 AsS' 123 .... 33-61 .... 33-55
6S 96 .... 26-23 15H0 .... 135 .... 36-88 .... 36-65
15HO 135 .... 36-88
3CaS,AsS> + 15Aq.... 366 .... 10000 366 .... lOO'OO .... 100-00
h, Bibasic, — Formed by digesting orpiment with hydrate of lime and
water, and filtering the solution from the arsenite of lime which is pre-
cipitated at the same time. The colourless filtrate, when left to evaporate
in the air, deposits feathery crystals of the salt a, and between these the
solution of 6 dries up to a brown amorphous mass. When the solution is
macerated with excess of orpiment, it takes up rather a larger quantity
of that compound, turning yellow and depositing a brown powder; if it
be then left to evaporate freely, it acquires a light red-brown colour, and
leaves a mass from which water extracts sulpharseniate of calcium, while
hyposulpharsenite of calcium remains behind : the above-mentioned yellow
solution, when mixed with alcohol before evaporation, gives a precipitate
which soon turns brown.
E. Sulpharseniate op Calcium. — a. Terbasic, — dCaS,AsS'.-~
Formed by digesting the aqueous solution of 5 with sulphide of calcium,
and either evaporating the liquid or precipitating by alcohoL Not
crystallizable : when precipitated by alcohol, it forms sometimes a
powder, sometimes a syrup, according to the quantity of water which it
contains. Easily soluble in water, but insoluble in alcohol.
b, Bibotdc, — 2CaS,A8S^. — Precisely analogous to the barium compound.
Dries up to a clear, faintly-coloured syrup, which, when further evapo-
rated in tlie air, turns yellow at the edges, and finally solidifies to a yellow
VOL. ly, X
306 ARSENIC.
opaque mass. This substance loses its water at 60^, but recovers it a^in
when exposed to the air, swelling up and cracking at the same time, and
detaching itself from the glass vessel which contains it. Dissolves easily
and without decomposition both in water and in alcohol. The syrupy
aqueous solution does not crystallize or solidify even at — 10°. When b is
distilled at a red heat, there remains a colourless residue which appears to
consist of 4CaS|AsS^ and, when roasted, in the air, is converted into an
almost equal weight of gypsum. The aqueous solution of h, when boiled
with pentasulphide of arsenic, takes up scarcely any of that compound.
(Berzelius.)
P. Arseniate op Lime and Ammonia. — Formation. — When lime-
water is mixed with a dilute solution of arseniate of ammonia, potash, or
soda, and hydrochlorate, nitrate or acetate of ammonia, no precipitate is
formed at first, but after a while, the double salt separates in needles. If
the solution is more concentrated, lime-water immediately produces a
copious precipitate, which, when digested in excess of the ammoniacal
salt, does not dissolve^ but becomes crystalline. If to a solution of 20
grains of sal-ammoniac in 2 ounces of lime-water, there be added a drop
of arseniate of ammonia or potash, a precipitate is produced which soon
disappears, and, in its place, crystals of the double salt make their
appearance after a while; if several drops of the alkaline arseniate are
added, a permanent crystalline precipitate is formed. On addin^^ arse-
nious acid to lime-water till a strong turbidity is produced and then
adding an ammoniacal salt, the liquid first becomes clear and afterwards
deposits crystals of the double salt. Di-arseniate of lime immersed in
solution of sal-ammoniac takes up one atom of ammonia, thereby ren-*
dering the liquid acid, and is converted into the same salt.
Preparation, — One part of arseniate of ammonia and 1 part of sal-
ammoniac are dissolved in 4 parts of water, and lime-water added in
successive portions, as long as crystals continue to form; the cryetab,
which increase in quantity when the liquid is set aside for 24 hours in a
cool place, are afterwards washed on a filter with water, and dried
between bibulous paper.
The salt crystallizes either in needles united together in stellated masses,
or else in rhombic tables laid one upon another like steps. The crystals
when exposed to the air, effloresce and lose their transparency. When
heated, they evolve water, ammonia [nitrogen gas], and arsenious acid,
while arseniate of lime remains behind. With moist lime they give off
ammonia. They are slightly soluble in water and in solution of sal-
ammoniac, easily in nitric or hydrochloric acid ; ammonia added to the
solution throws down the salt m the crystalline form, but not till after
some time, if the liquid is dilute. (Wach, Schw. 59, 285.)
Wach.
NH» 17 .... 5-41 .... 5-35
2CaO 56 .... 17-84 .... 17*52
AsO* 115 .... 36-62 .... 3583
14HO 216 .... 40-13 .... 4115
NH<0,2CbO,A80» + 13Aq 314 .... 10000 .... 99*85
The resemblance of this compound to the phosphate of magnesia and
ammonia, leads to the supposition that the quantity of water which it
contains does not exceed 13 atoms.
1
ARSBNIC AND MAGNESIUM, 307
Arsenic and Magnesium.
A. Absenite of Magnesia. — Magnesia heated to redness in a glass
tobe^ absorbs the vapours of arsenious acid passed over it, without
liberating arsenic. The compound only evolves arsenic when it is very
strongly ignited, and is thereby partly converted into arseniate of mag-
nesia. (Simon, Fogg. 40, 436.)
B. Arseniate op Magnesia.— a. Di<ir9eni(Ue, — Formed by preci-
pitating hydrochlorate or sulphate of magnesia with di-arseniate of soda.
— White powder, insoluble in water, but soluble in nitric acid. — The
precipitate obtained by mixing dilute solutions of 3 parts sulphate of
magnesia and 5 parts di-arseniate of soda, contains, on the whole,
15 atoms of water; of these, 12 atoms escape at 100^; the precipitate,
therefore, consists of 2MgO, HO, AsO'+2Aa. -i-12Aq. By exposure to
a bright red heat, it becomes insoluble in acios, (Qraham, Antu Pharm*
29, 24.)
6. MoruhaneniaU, — Gummy, soluble in water.
C. Hyposulpharsenite of MAGNEsicM.^Brown powder, like the
corresponding barium compound. (Berzelius.)
D. Sulpharsenite of Magnesium. — The aqueous solution becomes
light brown on evaporation, and dries up to a clammy syrup, and after-
wards to a hard mass, which is permanent in the air, and, with the excep-
tion of a small quantity of the compound C that may be mixed with it,
redissolves in water without further decomposition ; it is likewise soluble
in alcohol. The compound C is deposited, not only when the aqueous
solution of the salt is evaporated, but likewise when a concentrated solu-
tion is cooled down to —5^, crystals of the compound E being deposited at
the same time. (Berzelius.)
E. Sulpharseniate op Magnesium. — a, Terhasic, — SMgS, AsS*. —
Bihydrosulphate of magnesia is added to a solution of & as long as
hydrosulphuric acid continues to be evolved, and the solution afterwards
evaporated, or, if it be not too dilute, cooled quickly down. — Colour-
less, radiating crystals, which become moist on exposure to the air.
Alcohol extracts from them the compound 6, and leaves a compound
of 1 At. AsS*, with more than 3 At. MgS, which is nearly insoluble
in water; the same compound remains behind, in the form of a white,
porous, un fused mass, when 6 is heated to redness in a retort. Potash
added to the aqueous solution of a precipitates magnesia, and converts
the salt into a solution of the corresponding potassium compound.
5. B {basic. — Non-crystalline, lemon-yellow mass, which is permanent
in the air, does not absorb water from the air, dissolves in water in
all proportions, and is not precipitated from the solution by alcohol.
(Berzelius.)
F. Arseniate op Magnesia and Ammonia. — Formed by adding a
solution of tris-arseniate of ammonia to sulphate, nitrate, or hydro-
chlorate of magnesia, as long as a translucent crystalline precipitate
continues to form, and afterwards washing and drying the precipitate.
It effloresces slowly in the air, dissolves with great mffioulty in water,
but easily in acids. (Wach, Schio, 59, 288.)
X2
308 ARSENIC,
Wach.
NH» 17 .... 5-88 .... 5-88
2UgO 40 .... 13-84 .... 13-93
AsO* 115 .... 39-79 .... 3945
13HO 117 .... 40-49 .... 4074
NH<0,2MgO,A80* + 12Aq. 289 .... 10000 .... 100-00
1 Levol {Ann. Ckim, Phyz, 17, 501) Las obtained the same salt, with
10 atoms of water, by mixing a solution of magnesia containing sal-
ammoniac, with an ammoniacal solution of arseniate of ammonia. It
separates in small crystals. Loses 44*26 per cent, by ignition, the
residue consisting of 2MgO, AsO^ IT
G. SULPHARSBKIATE OF MAGNESIUM AND AmMONIUM. — NH^,
2MgS, AsS'f — Obtained by adding alcohol to an aqueous solution of the
mixed sulpharseniates of^^ ammonium and magnesium. After a few
seconds, the terbasic compound is precipitated in delicate white needles.
By exposure to the air, it is slowly converted into the bibasic salt (by
loss of hydrosulpburic acid), and turns yellow. It is easily soluble in
water. The aqueous solution, when left to spontaneous evaporation^
gives off hydrosulphate of ammonia, and dries up to a yellow, non-
crystalline mass, from the aqueous solution of which the terbasic com-
pound may be again precipitated by alcohol. (Berzelius.)
H. Arseniate of Lime and Magnesia. — BeruUiU, — Specific gra-
vity 2*52; white; of waxy lustre; easily pulverized. Before the blow-
pipe, it turns grey without melting or losing water. With borax and
microcosmic salt it froths up, gives off an odour of arsenic, and forms a
clear glass. With soda it effervesces, and forms a mass slightly coloured
green by manganese. Perfectly soluble in nitric acid. (Kiihn, Ann*
Fharm. 34, 211.)
At. Berieliite. Kuhn.
CaO 15 .... 420 .... 22-27 2322
MgO 14 .... 280 .... 14-84 15-68
MnO 1 .... 36 .... 1-91 2-13
A»0« 10 .... 11-50 .... 60-98 58-61
C0> (and a trace of Fe«0») .... 0-30
1886 .... 100-00 99-84
(3CaO, AsO*) + (3MgO, AsO«) ; part of the magnesia is replaced by
manganous oxide.
Pierophamuxeolite w hydrated arseniate of lime and magnesia, bat
contains a large excess of magnesia^ and cannot be reduced to any simple
stoichiometrical formula.
Arsenic and CERnm.
^ A. Cerous Arseniate. — a. Sibasic, — Formed by digesting cerous
oxide in aqueous arsenic acid. — ^White powder insoluble in water.
h. Monobctnc? — By dissolving a in excess of arsenic acid, a liquid is
obtained, which does not crystallize on evaporation, but yields a trans-
parent and colourless jelly. (Hisinger <fe Berzelius.)
i
ARSENIC AND YTTRIUM, 309"
B. Cerous Hvposulphabsenite. — A compound of bisulphide of
arsenic witli protosulphide of cerium. Preparation, similar to that of the
corresponding barium compound. Red. (Berzelius.)
C. Cbrous Sulpharsenite. — J3ib<i9ic.'^2CeS, AeSK — The solution of
disnlpharsenite of sodium forms an orange-yellow precipitate with cerous
salts. This precipitate acquires a finer colour on drying. When heated
to commencing redness, it fuses to a transparent substance, which loses
part of its sulphur-acid, but remains liquid and transparent as lon^ as
the heat is continued. By roasting in the air, it is readily conrerted into
sulphate. Very slightly soluble in water, to which it imparts a yellow
colour. (Berzelius.)
D. Cebous Sulpuarsbniate. — Terhcuic and Bihanc Salts. — Formed
by precipitating a cerous salt with terbasic or bibasic sulpharseniate of
sodium. — In both cases, a pale yellow precipitate is formed, which acquires
a brighter colour when dry. (Berzelius.)
E. Cerig Sulpharseniatb. — 200*8' +3AsS*. — By precipitating a
eerie salt. Yellowish white precipitate, slightly soluble in water, and
therefore not appearing if the solutions are very dilute.
Arsenic and Yttrium.
A. Arseniate op Yttria.— a. ^tfrJawc/— By treating b with
ammonia. (Berzelius.)-^The same salt is obtained by precipitating a salt
of yttria with di-arseniate of soda; the white precipitate dries up to
yellowish brown, homy lumps, which, when treated with nitric acid, first
become gelatinous and then dissolve*
h. Bibanc? — By adding a salt of yttria to di-arseniate of soda in
excess. — White heary precipitate, which becomes somewhat dark on
drying, is easily soluble in nitric acid, and is left behind as a crystalline
crust when the acid eraporates. (Berlin.)
c, Monobasief — Aqueous arsenic acid dissolres yttria; on heating the
solution, arsenic acid is precipitated in the form of a white powder.
(Ekeberg.)
B. Sulpharsenite of Yttrium. — The saturated solution of orpi-
ment in hydrosulphate of soda ^ves with salts of yttria a light yellow
precipitate, part of which remains in solution and colours the liquid
yellow; no sulphuretted hydrogen is evolved. The precipitate is yellow
even after drying ; it gives off but a small quantity of sulphuretted
hydrogen when treated with acids. Ammonia decomposes it with sepa-
ration of yttria. (Berzelius.)
C. Sulpharseniate op Yttrium. — ^When hydrate of yttria is
digested with water and pentasulphide of arsenic, small quantities of
the two substances are dissolved, the liquid acquiring a yellow colour,
and yielding a precipitate when treated with acids. A solution of ter-
basic or bibaaic sulpharseniate of sodium produces no turbidity in solutions
of yttria-salts. (Berzelius.)
310 ARSENIC.
AjEUHSKIO AND OlUCIKVH.
A. Arsenide op Glucinum.'— These two metals, when heated
together, unite without riiible oombustion, and form a fused, grey, pul-
yerulent alloy, which^ when treated with water, erolyes arseniuretted
hydrogen. (Wohler.)
B. Arsbniatb ov Glucina.— The bihasio salt is insoluble in water,
but dissolves in excess of arswio acid, forming an uncrystallizable acid
salt. (Berselius.)
C. and D. — Sulpharsenitb and Sulfharseniate op Glucinxjm. —
Analogous to the yttrium compounds. (Berzellus.)
Arsenic and Aluminum.
A. Arsbnidb op Aluminum. — ^When a pulverulent mixture of the
two metals is heated to redness, combination takes place with slight
incandescence, and a dark grey powder is formed, which assumes the
metallic lustre when rubbed, smells slightly of arseniuretted hydrogen,
and evolves that gas slowly in cold, but rapidly in warm water. (Wohler,
Poffg. 11, 161.)
B. Arseniate op Alumina. — a. The more neutral salt. — Formed
by double decomposition. — White powder, soluble in acids but not in
pure water. — From the solution of this salt in hydrochloric acid, sulphite
of ammonia precipitates hydrate of alumina on boiling, the whole of the
arsenic remaining dissolved in the form of arsenious acid. (Berthier, i\r.
Ann. Chim, Fhys. 7, 76.^
b. Acid Salt. — Soluble in water, but not crystallizable.
[The oombinations of Bolphide of aluminum with sulphide of anenic are not satis-
factorily made out. (Benelius.) ]
Arsenio ani> Thorinum.
Arsbniatb op Thorina. — ^By double affinity. — ^White, flocculent
precipitate, insoluble in wator and in aqueous arsenio acid. (Berzelius.)
Arsenic and Zirconium.
A. Arsbniatb op Zirconu. — ^By double affinity. — Precipitate inso-
luble in water. (Berzelius.)
. B. Htposulpharsenitb op Zirconium. — SZrSAsS*. — Hyposul-
pharsenite of potassium dissolved in water fives with salts of zirconia, a
dark brown, translucent precipitate, which slowly settles to the bottom of
the liquid. (Berzelius.)
C. Sulpharsenitb op Zirconium. — The saturated solution of orpi-
raent in hydrosulphate of soda gives with zirconia-salts, an orange-yellow
ARSENIC AND MOLYBDENUM. 311
precipitate, which becomes darker on drying, and is not decomposed by
acids ; the sopematant liquid is yellow, oecaose it holds a little of this
compound in solution. (Berselius.)
D. SuLPHABSBMiATB OF ZiRCONiVM. — The aqueous solution, either
of the terbasic or bibasic sodium compound, gives with sirconiaHsalts
(after a few minutes), a lemon-yellow precipitate, which becomes
orange-yellow on drying, and, like sulphide of zirconium, is not decom-
posed by acids. (Berzelius.)
AitsEiao AND SiLicnrM.
A. Arseniate of Silica f — Arsenic acid, fused in an earthen cru-
cible, combines with the silica and forms a glass, which is soluble or
insoluble in water, according to the amount of silica which it contains.
According to Scheele, this glass contains arseniate of alumina. Accord-
ing to the same authority, also, aqueous arsenic acid has no action on
hydrate of silica.
B. Glass coTUaining Arsenioui AcicL — A large proportion of arsenious
acid giyes a milky appearance to glass.
Arsenic and Titanium.
Arseniate of Titanic Oxide. — Arsenic acid precipitates from salts
of titanic oxide, white flakes resembling precipitated alumina, which
dry up to a shining vitreous mass, and dissolve both in excess of the
titanium solution and in excess of arsenic acid. If the titanium solution
contains ferric oxide, that substance is precipitated at the same time.
(H. Rose.)
Arsenic and Moltbdenttm.
A. Arseniate of Moltbdous OxiDE.-<-Behaye6 exactly like the
corresponding phosphate. (Berzelius.)
B. Arseniate of Moltbdio OxiDB.^-a. Monobancf Formed by
precipitating hydrochlorate of molybdic oxide with di-arseniate of soda.
b. Acid SaU^'^The solution of hydrated molybdic oxide in excess of
arsenic acid has a great inclination to turn blue, even when left to spon-
taneous evaporation. It forms with ammonia a deep red solution, which,
when exposed to the air, deposits nothing, but becomes gradually
decoloriz^. (Benelius, Fogg. 6, 846.)
C. Arseniate of Moltbdio Acid. — Molybdic acid, treated with
arsenic acid, yields (a) a basic yellow compound, insoluble in water, and
(6) a solution containing excess of arsenic acid. The latter, when evapo-
rated to the consistence of a syrup, yields crystals. Alcohol decomposes
these crystals, separating white flakes, which, however, are subsequently
redissolved. The resulting alcoholic solution turns blue on evaporation,
and yiekb no more crystals. (Beraelius, Fogg, 6, 383.)
312 ARSENIC.
D. MoLTBDic SuLPHARSEMiTE. — A compound of tenulphide of
arsenic with tersnlphide of molybdenum. When hjdrosnlphate of soda
saturated with orpiment, is added to a solution of molybdic acid in
hydrochloric acid, a dark brown powder is precipitated/ which turns black
on drying, and when distilled resdiij gives off orpiment [and sulphur)]
and leaves bisulphate of molybdenum. (Berzelius.)
Aqueous sulpharseniate of sodium^ mixed with solution of molybdic
acid, forms a yellowish brown liquid, which gradually deepens in colour^
but without forming a precipitate. (Berzelius.)
Abbenic and Vanadiuii.
A. Arsbniate of Vanadic Oxide.— a. J9c»tc.*-Aqneous arsenic
saturated with hydrate of vanadic oxide, yields, on evaporation^ a gummy
mass easilv soluble in water, besides crystalline grains of b.
b. Acid Salt, — The solution of hydrated vanadic oxide in excess of
arsenic acid, deposits, on evaporation, a crust of small, light-blue, crystal-
line grains, which may be freed from the acid mother-liquid by wsishing
with water. The salt dissolves but very slowly, even in boilmg water,
or in water containing arsenic acid, but when once dissolved, no longer
separates again on cooling; the addition of alcohol, however, precipi-
tates it. Hydrochloric acid dissolves it quickly. (Berzelius.)
B. Arseniatb of Vanadic Acid. — Formed by evaporating the
solution of arseniate of vanadic oxide till it turns red and evolves nitric
acid vapours. On cooling, a lemon-yellow compound separates, analogous
to phosphate of vanadic acid. (Berzelius, Pogg, 22, 31, and 42.)
When sulphate of vanadic oxide is added to aqueous sulpharseniate of
sodium, no precipitate is formed, but the blue solution becomes colourless.
(Berzelius.)
Arsenic and Chromium.
Hydrochlorate of chromic oxide mixed with arsenite of ammonia gives
no precipitate with free ammonia. (Bonnet, Pogg, S7, 303.)
A. Arseniate of Chromic Oxide. — Arseniate of potash gives an
apple-green precipitate with salts of chromic oxide. (Moser.)
IF When aqueous arson ious acid is added to a solution of mono-
chromate of potash, the liquid acquires a fine green colour, and in a few
minutes coagulates into a tremulous jelly, which, when dried at 100°, yields
a substance whose empirical formula is dA60^ + 4K0 + 3CrH)' + 10Aq.
If the liquids be mixed in the reverse order, the green colour is produced,
but no precipitate. (Schweitzer, J, pr. Chem, 39, 267.) IF
B. Chromic Sulpharsenite. — 2Cr'S',3AsS*, — The saturated solution
of orpiment in hydrosulphate of soda gives with salts of chromic oxide a
dingy grejy^ish-yellow precipitate, which turns greenish-yellow on drying.
This precipitate melts when heated, giving off orpiment, and leavmg a
shining dark-grey residue, which yields a greenish-grey powder. This,
when more strongly heated, gives off more orpiment and leaves a grey,
pulverulent, soft compound which contains a large quantity of chromic
ARSENIC AND URANIUM. 313
salphide with bat little arsenious sulphide, and, when heated in the air,
takes fire, ^ves off arsenious and sulphurous acid, and is conyerted into
chromic oxide.
C. Chromic Sulpharsbniate. — Salts of chromic oxide give a dirty
yellow precipitate with the aqueous solution of terbasic or bibasic sulph-
arseniate o£ sodium.
Arsenic and Uranium.
A. Arseniatb of Uranous Oxidb. — Terhastc^^Formed. by preci-
pitating the solution of b in hydrochloric acid with excess of ammonia.
Green, very bulky precipitate, which, after ignition, contains 66*73
per cent, of uranous oxide. Bibasic, — Hydrochlorate of uranous oxide is
completely precipitated by di-arseniate of soda. The green precipitate,
when heated, gives off 12 -54 per cent, of water, and therefore consists of
2UO,AsO^+4Aq. On ignition, a few crystals of arsenious acid are
sublimed from it, and uranic oxide is produced. It dissolves in hydro-
chloric acid more readily than the corresponding phosphate. (Rammels-
berg, Fo^g, 59, 26.)
B. Arseniatb of Uranic Oxide.— <Light yellow powder insoluble in
water. (Berzelius.)
IT According to Werther (J. pr, Ckem, 13, 321) arsenic acid forms
with uranic oxide two compounds analogous to the phosphates of that
base (p. 17).
a. Di-arsenicUe. Prepared like the diphosphate. By precipitating
uranic acetate with arsenic acid, a pale yellow salt is obtained, having the
following composition : —
Calculation. Werther.
2U«0» 288 .... 59-40 59-05
AbO* 115 .... 23-83 23-75
9H0 81 .... 16-77 17-20
(2U20»,HO)AbO* + 8HO .... 484 .... 10000 10000
The salt loses 15*1 per cent. (8 atoms) of water at 120^.
5. Mono-arseniate. — Prepared by evaporating an excess of arsenic
acid in contact with uranic oxide, acetate, or nitrate, and leaving the
residue to dry over sulphuric acid. Small yellow crystals containing 5
atoms of water, 8 of which go off at 150^.
u«o>
A«0*
5H0
144
115
45
••••
47-25
37-92
14-83
Wcrthcr.
48-2
382
14-0
ru«o»,2H0
»)A80» + 3HO
304
■•••
10000
100-4
C. Arseniate of Uranic Oxtdb and Soda. — ^When a solution of
nitrate of uranic oxide is mixed with excess of basic arseniate of soda,
3NaO,AsO^ the whole of the uranic oxide is precipitated in the form of a
pale yellow terbasic salt^ in which one atom of uranic oxide is replaced
by soda.
314 ARSBNIC.
Weith«r«
NaO 31-2 .... 6-4 59
2V'G^ 288-0 .... 600 60-7
AsO^ 115-0 .... 24-2 23-5
5HO 450 .... 9-4 9*9
(NaO,2U20»)AiO» + 5HO.... 4792 .... 1000 lOO'O
In Werther's analyBis the arsenic acid was estimated by difference.
All the alkalis^ especially ammonia, have a great tendency to enter by
substitution into the compounds of nranio oxide with phosphoric and
arsenic acid. (Werther.) i
D. Uranic Sulpharsbnitb.— a compound of tersulphide of arsenic
with scsquisulphide of uranium. Hydrosulphate of soda saturated with
orpiment gives with uranic salts a deep yellow precipitate, which becomes
greenish yellow on drying, and yields a dingy light-yellow powder.
This precipitate when heated out of contact of air becomes semifluid,
gives off part of its orpiment, and, after long continued ignition, is
ultimately converted into an unfused, porous, greyish-brown mass, which
appears to be a more basic compound. (Berzelius.)
E. Uranic Sulpharseniate. — Pentasulphide of arsenic with scsqui-
sulphide of uranium. Aqueous terbasic or bibasic sulpharseniate of
sodium precipitates from salts of uranic oxide, a dingy yellow substance,
which appears deep yellow after drying, and dissolves in excess of sulph-
arseniate of sodium, forming a dark brown solution. (Benelius.)
Arsenic and Manganese.
A. Arsenide of Manganese.— -The native arsenide resembles Pyro-
lusite : sp. gr. 5' 55; hard, greyish- white. When exposed to the air it
becomes covered with a black powder. Fuses on platinum-foil and
combines with the platinum. Before the blowpipe, it burns with a blue
flame, emitting the garlic odour and producing white fumes of arsenious
acid. Dissolves completely in aqua-regia and in large quantities of
nitric acid. (Kane, N, Quart. J. of Sc. 6, 881; also Fogg. 19, 145.)
Probably a mixture of the two metals.
Kane.
2Mn
56
• •••
4275
45-5
As
75
• •It
57-25
.... Oi'o
Fe
■ ■••
• • >i
trace
Mn^As:
131
• ■•■
10000
"/'o
B. Arseniate of Manganous Oxide. — a. JBibasic. — Arsenic acid
produces a turbidity in solution of acetate of manganous oxide, but not in
the hydrochlorate. The salt is prepared: 1. By double decomposition.
— 2. By treating carbonate of manganous oxide with aqueous arsenic
acid, the latter not being in too great excess. White, and, when pre-
pared by (2), crystalline-granular. At a red heat, it does not decompose
fScheele, Opu$c. 2, 66)^ but fuses to a dark red, very fluid glass, which
does not give up its arsenic till it is treated with charcoal, but then gives
up the whole of it. (Liebig, Handwbrierbuch^ 1, 507.) Insoluble in
water, but soluble in nitric and sulphuric acid.
ARSENIC AND MANGANESE. 316
b, MoTiobanc, — Manganotts salts are not precipitated by mono-arBe-
niate of soda. (Pfaff.) The salt a dissolves in aqueous arsenic acid.
(John.)
C. Htpgsulphabsenitb of Manganese, — Dark red precipitate.
(Berzelius.)
D. SuLPHARSENiTE OF Manoanese. — Hjdrosulphate of soda saturated
with orpiment precipitates from neutral manganous salts an aurora-red
substance, which becomes darker on drying and yields an orange-red
powder. When heated in close vessels, it fives off tersulphide of arsenic
and is converted into a yellowish-green, pulverulent compound containing
a large quantity of sulphide of manganese and a small quantity of orpiment.
This compound is infusible and suffers no further decomposition by heat;
when it is digested in hydrochloric acid, sulphuretted hydrogen is evolved,
manganous oxide dissolved, and orpiment precipitated.
E. SuLPHARSENiATE OP Manoanese. — a. ASpir6a«ic.^6MnS, AsS*. —
Formed by digesting the yellow powder of b in strong ammonia ; penta-
sulphide of arsenic is then dissolved, and there remains a brick-red powder
which is permanent in the air, has a pale brick-red tint when dry, is
somewhat soluble in water, and, when ignited at oue point, continues to
burn.
b, Bihasic. — 2MnS,AsS*. — ^Formed by digesting freshly precipitated
hydrated sulphide of manganese with water and pentasulphide of arsenic.
The new compound partly dissolves in the water, partly remains at the
bottom in the form of a yellow powder, which however dissolves in a
lar^r quantity of water. The solution yields sulphur on evaporation,
and afterwards deposits a lemon -yellow mass, which, from having
undergone a certain amount of decomposition, no longer dissolves com-
pletely in water. Acids precipitate pentasulphide of arsenic from the *
solution and liberate hydrosulphuric acid. The same compound is
obtained when carbonate of manganous oxide is boiled with water and
pentasulphide of arsenic, but arseniate of manganous oxide is likewise
formed at the same time. The aqueous solution of sulpharseniate of
sodium does not precipitate manganous salts. (Berzelius.)
F. Arseniate op Manganous Oxide and AMMONiA.^When a
mixture of chloride of manganese and ammonia is added to the aqueous
solution of arsenic acid or arseniate of ammonia— especially if heat be
applied — a flocculent precipitate is formed, consisting of manganous
arseniate, which is soon converted into the crystallized double salt. This
salt is washed with water deprived of air by boiling. Sometimes forms a
reddish-white crystalline powder, sometimes small reddish crystalline
grains. Permanent in the air. When heated, it ^ives off water and
ammonia, and leaves di-arseniate of manganous oxide. With potash it
evolves ammonia, forming arseniate of potash, and leaving di-arseniate of
manganous oxide. Dissolves readily in dilute acids, but not in water or
alcohol. (Otto, J. pr, Chem. 2, 414.)
Otto.
NH» 17 .... 5-30 6-62
2MnO 72 .... 22-43 22'8I
AsO*i 115 .... 35-82 36*89
13H0 117 .... 36-45 34*68
NU«0,2MaO,ABO«+ 12Aq 821 .... lOO'QO ~. 100*00
S16 ANTIMONY.
The supposition that the salt contains only 1 2 atoms of water agrees
most nearly with Otto's analysis; but he himself considers it as possible
that the salt which he analyzed and which was dried at 1 6% may hare
lost some of its water; with 13 atoms of water, this salt corresponds
exactly to phosphate of magnesia and ammonia.
Other Compounds of Arsenic.
With Antimony, Bismuth, Zinc, Tin, Lead, Iron, Cobalt, Nickel,
Copper, Mercury, Silrer, Gold, Platinum, PaUadium, and Rhodium —
forming white, and mostly brittle and easily fusible alloys, which, when
ignited out of contact of air, either retain their arsenic or give it up but
partially — ^but if the air has access to them during ignition, evolve part of
their arsenic in the form of arsenious acid, and retain the rest in the form
of an arseniate of the metallic oxide. When ignited with nitre and
carbonate of potash together, they yield arseniate of potash, and when
ignited with potash-liver of sulphur they yield arsenical sulphur-salts of
potassium, which may be washed out with water.
Chapter XXV.
ANTIMONY,
Bergmann. De antimonialibns sulphuratis. Opuse* 8, 164.
Thenard. Ann. Chirn, 32, 257.
Proust. A. GM. 5, 543; also, GUb. 25, 186.
Berzelius. Oxides of Antimony. Schtv. 6, 144, and 22, 69. — Sulphide
of Antimony. Schw. 34, 5S.—Fogg. 20, 365; 37, 163.— Fluoride of
Antimony. Pogg, 1, 34, and 200.
Berthier. Antimony and Sulphide of Antimony. Ann, Chim, Fhys, 22^
239; and 25, 379.
H. Rose. Compounds of Antimony with Chlorine and Sulphur. Pogg, 3,
441,
Yauquelin. Antimonide of Potassium. Ann, Chim, Phys. 7, 32; also^
JSchw. 27, 219.
Semllas. Antimonides of Potassium and Sodium. J, Pkya. 91, 123;
93, 115; also, Ann. Chim. Phys. 18, 217. Further, Ann. Chim,
Phys. 21, 198; also, Kastn. Arch. 1, 113.
Pagenstecher. Metallic Antimonio-Sulphides. Repert. \Ay 2\2,
Rammelsberg. Metallic Antimonio-Sulphides. Pogg. 52, 193.
Mitscherlich. J. pr. Chem. 19, 455; also, Ann. Chim. Phys. 73, 394.
Capitaine. J. Pharm. 25, 516; also, J. pr. Chem. 18, 449.
Liebig. Handworterimch der reinen und angewandten Chemie, 18, 449.
On Antimoniuretted hydrogen : L. Thomson. PhU. Mag. J. 10, 353;
also, J. pr, Chem, 11, 369.— Pfaflf. Pogg, 42, 339.— Simon. Pogg.
ANTIMONY. 317
42, 369. — ^A. Vogcl. J^ pr. Chim, 13, 57. — Lassaigne. J, Chim.
Med, 16, 638; 17, 440. — L. A. Bucbiier, Eepert. 63, 250.
On Mineral-Kermes and Golden Sulphuret, Alphabetically: Biandes, £r.
Arch. 37, 257. — Schw. 62, 209. — Buchner, Repa-t. 13, 169 and 203.
— Bucbolz, Junior, Berl. Jahrh, 29, 1, 26. — Cluzel, Ann. Chim, 63,
155.— Duflos. Br, Arch, 31, 94; 36, 21S,^Schw. 62, 210; 67, 269.
Kattn, Arch, 19, 61 and 289. — Fourcroy, Crell. Ann. 1788, 1,423.
— Fuchs, Pogg. 31, 578. — Gaj-Luasac, Ann. Chim, Phy$, 42, 87 j
also, Schw. 57, 252; also, Pogg. 17, 320. — Geiger, Eepert, 9, 274. —
Mag. Pharm. 29, 229. — Geoffroy, M&m. de VAcad, de Paris, 1734,
593; 1735, 94. — Hennsmann, Taachenb. 1822, 184.— 0. Henry, J.
Pharm. 14, 545 ; also, N. Tr. 18, 2,194.— Jahn, N. Br. Arch. 22, 43.
— Liebig, Mag, Pharm. 35, 120; Ann. Pharm. 7, 1 ; 31, 57. — Otto,
Ann. Pharm. 26, 88. — Pagenstecber, Repert. 14, 194, and 545. —
Pbillips, Ann. Phil. 25, 378.— Rammelaberg, Pogg, 52, 204.— Robi-
quet, Ann. Chim. 81, 317.— H. Rose, Pogg. 17, 324; 28, 481; 47,
323. — Scbrader, N. Oehl. 3, 159. — Soubeiran, J. Pharm. 27, 294. —
Tbenard, Ann. Chim, 32, 257; also. A, Tr. 9, 1, 174.— Thomson,
Schw. 17,396; also, Ann. Chim. 93, 138.— Tromsdorff, A. Tr. 8,
1, 128.— A. Vogel, Schw. 33, 291.
Poggiale. Compt. Rend. 20, 1180; also Ann. Pluzrm. 56, 243.
Fremy. jV. Ann* Chim. Phy$. 33, 404 ; also J. pr. Chan. 45, 209.
Spiesgglam, Spiessglcu, Spiessglamkonig, Antimony Antimxmium,
Stibium, Antimaine.
History. A few of tbe oomponnda of antimony appear to bave been
known to the ancients, but not antimony itself, the preparation of which,
together with that of many of its compounds, was first described by
Basilins Valentinus towards tbe end of the fifteenth centnry. The oxides,
and many of the other compounds of antimony, were described by Proust^
and more especially by Berzelius.
Sources. Rarely native; — as antimonio oxide; as antimonions acid or
antimonic acid ; as antimoniate of lime? very frequently as sulphide of
antimony*; as sulphide of antimony in combination with other metallic
sulphides : in Feather-ore, Jamesonite, Plagionite, Zinkenite, Boulange-
rite, Berthierite, Boumonite, Antimonial copper glance. Grey copper,
Miargjnrite, Dark red silver. Brittle sulphide of silver, Polybasite; — in
combination with another metal : in arsenide of antimony, antimonide of
nickel, and antimonide of silver : with another metal, together with a
metallic sulphide in Nickeliferous grey antimony.
* All the German and French sulphide of antimony occnnring in commerce, except-
ing that from Montla9on, Department de I'AUier, contains from /^ to y*o of its weight
of arsenic. Metallic antimony, flores antimonii, basic sulphate of antimonic oxide,
kermes, snlphnr auratnm, Titmm, and crocns antimonii, antimonium diaphoreticam
ab1utnm»->aU these substances, prepared from sulphide of antimony containing arsenic,
are contaminated with arsenic (the metallic antimony containing from ^^ to , ^^ i^
weight, the kermes, ^i^ to ^^^); but crystallized tartar emetic (the arsenic remaining in
tbe mother-liquor) and the powder of algaroth are free from this impurity. (Semllas,
Ann. Ckim. Phy». 18, 217.) The larger crystals of tartar emetic, however, which are
principally formed in the mother-liquid, likewise contain arsenic. (Martins.)
318 ANTIMONT.
Preparation.-^l. Powdered grey sulphide of antimony, mixed with
about half its weight of charooaf powder to prevent caking, is roasted at
a gentle heat (on the small scale, on a roasting-dish ; on the large scale,
in a reverberatory furnace), with constant stirring, the fire being gradu-
ally increased, but not sufficiently to fuse the mass. The sulphur escapes
in the form of sulphurous acid, and there remains a mixture of antimo-
nious acid with a small quantity of antimonic oxide amounting to about
I of its weight (Geiger & Reimann, Mag. Fharm. 17, 136), and traces of
sulphide of antimony remaining undecomposed, the Cola ArUimcnii grisea
8, per se or Cinis Antimonii. This residue is then mixed with half its
weight of cream of tartar — or with 1 part of charcoal and ^ pt. potash — or
with charcoal powder saturated with an aqueous solution of carbonate of
soda — ^and fused in a covered crucible at a low red heat; the fused mass
is then poured out into a hot mould partly filled with tallow, and the
mould gently tapped to make the metal sink to the bottom. The slag at
the top consists of a mixture of alkaline carbonate, double sulphide of
antimony and potassium (or sodium) and charcoal. The charcoal sepa-
rates the oxygen from the antimony and from a portion of the alkali; and
the potassium or sodium thus elimmated separates the sulphur from part
of the sulphide of antimony still present, and then, in the form of sul-
phide, unites with the remainder. — 2. A mixture of 8 parts of sulphide of
antimony and 6 parts of cream of tartar is heated in a crucible, nearly to
redness, and from 2 to 3 parts of nitre are added till the mass becomes
perfectly fused. Or a mixture of 8 pts. of sulphide of antimony, 6 pts.
of cream of tartar, and 3 pts. of nitre, is projected by small portions at
a time into a red-hot crucible placed in a furnace, and the whole heated
for a short time, till perfectly fused. The mass is then poured out as
before. The lower stratum consists of metallic antimony, the upper of
double sulphide of antimony and potassium mixed with charcoal. The
charcoal in the black flux (III. 20) withdraws oxygen from the potash;
the potassium thus separated decomposes a portion of the sulphide of
antimony, setting the metal free; and the resulting sulphide of potassium
unites with the still undecomposed sulphide of antimony. Probably
according to the following equation :
5SbS3 + 6KO + 6C :=« 3(2KS, SbS^) + 2Sb + 6C0.
According to this, only \ of the antimony contained in the sulphide
should be obtained in the metallic state, or 29*15 parts of regains from
100 parts of the sulphide of antimony. This result accords with actual
experience, 100 parts of sulphide ot antimony being found to yield 27
parts of antimony. According to Liebig, however, by leaving out the
nitre in this process, 100 parts of sulphide of antimony produce 45 parts
of the metal. — 3. An intimate mixture of 8 parts of sulphide of anti-
mony with 1 pt. of dry carbonate of soda and 1 pt. of charcoal heated
in an earthen crucible, and constantly stirred with a stick till it fuses
quietly, and then poured out into the casting mould — yields 5*7
parts (71 per cent.) of antimony, which is afterwards purified from iron
and copper by fusion with ^ its weight of nitre. (Duflos, Br, Arch, 36,
277; 38, 158.) — In this process, rather more than 3 atoms of carbonate
of soda and charcoal are used to 1 atom of tersulphide of antimony, so
that a sufficient quantity of sodium is set free to separate the whole of
the sulphur:
SbS3 + 3NaO + 3C = Sb + 3NaS + 3C0.
ANTIMONY. 319
The fusion must be oontinned for a long time, daring which the mass is
very apt to boil oyer, and the antimony to bum away ; the total amount
obtained is only 66 per cent, and the antimony still contains the whole
of the other metals which were present in the sulphide. (Liebig, Mag,
Fharm. 35, 120.) — 4. A mixture of 177 parts (1 at.) of sulphide of anti-
mony with at most 82 parts (3 at.) of iron filings or iron nails is heated
to bright redness in a closely covered crucible, and then left to cool.
SbS» + 3Fe = Sb + 3FeS.
The iron separates the whole of the sulphur, even at a gentle heat ; but
a stronger heat is required to fuse the sulphide of iron, and cause the
antimony to form a distinct stratum beneath it; at this high temperature,
the antimony is apt to bum away if the crucible be not well covered ;
hence a layer of charcoal powder over the mixture is useful. — The addi-
tion of carbonate of potash or soda, or of nitre, accelerates the fusion,
because double sulphide of iron and potassium or sodium is thereby
formed, which is more readily fusible than pure sulphide of iron. For ex-
ample, 22 parts of nitre are added to a strongly ignited mixture of 100
parts of sulphide of antimony and 33 pts. of iron, or 6 parts of nitre to 100
parts of sulphide of antimony and 47 pts. of iron; — or 100 parts of sulphide
of antimony, 42 pts. of iron, from 10 to 50 pts. of dry carbonate of soda,
and 2 to 5 pts. of charcoal are melted together. Berthier, however, found
it most advantageous to fuse together 100 parts of sulphide of antimony,
55.... 60 parts of smithy scales, 45 parts of carbonate of potash, and 10
parts of charcoal; this mixture yielded 69 parts of antimony; the mass
however was found to froth up considerably. Liebig {Mag, Pharm. 35,
120) gives the preference to this method; but the regulus which it
separates from sulphide of antimony containing lead, is contaminated with
that metal. Ann Pharm. 22, 62.) A mixture of 100 parts of sulphide of
antimony, 42 parts of iron, 10 parts of dry sulphate of soda, and 2^ parts
of charcoal, yield between 60 and 64 parts of antimony. (Liebig, Handr
worterbuch) — The slag obtained in the second process likewise yields a
large quantity of antimony by fusion with iron, because the double sulphide
of antimony and potassium is thereby converted into doable sulphide of
iron and potassium.
Antimony obtained by the first, second, and third processes, — the
Regulut Anttmonii simplex «. wlgaris which solidifies in the mould, and
has a stellated stracture on the upper sorface, whence it has been called
Regulus Antimonii stellcUus — may contain sulphur, potaseium, arsenic,
lead, iron, and copper; the antimony prepared by the fourth method,
Regulus Aniimanii martialis, may contain a large quantity of iron, cspe^
cially when the iron has been used in excess. The powdered antimony
may be freed from iron by fusing it with sulphide of antimony; from sul-
phur, by fusion with carbonate of potash ; from sulphur and potassium,
by fusion with nitre ; and, according to Bercelius, from sulphur, potas-
sium, arsenic, and iron, by fusion with from ^ to 1 part of antimonic oxide.
By fusing snlphide of antimony, or the slag obtained in the second
process, with tin, lead, copper, silver, &c., an antimony is obtained,
which may contain small quantities of these metals; antimony thus
prepared was formerly called Regulus Antimonii jovtalis, saturninus,
venereus, lunaris, &o.
PurtJicaJtion. — 1 . By the following method, commercial antimony and
likewise that prepared on the small scale, may be perfectly freed from
sulphur, arsenic, iron, (when not in too large quantity,) and copper, but
1
320 ANTIMONY.
not from lead ; bence the antimonj subjected to tbis process, must be
previously freed from lead. A mixture of lb' parts of coarselj pounded
antimony with 1 part of grey sulphide of antimony and 2 parts of dry
carbonate of soda, is fused in a hessian crucible for an hour, care being
taken to prevent any charcoal from falling into the mass. When cold,
the crucible is broken, and the slag completely separated from the metal,
which is again coarsely pulverized, fused with 1^ pt. dry carbonate of
soda for an hour, and, lastly, after cooling and removal of the slag, once
more fused with I part of carbonate of soda. In this manner, 15 parts
of pure antimony are obtained. (Liebig, Ann. Fharm. 19, 22.) The
sulphide of antimony converts the other metals, except the lead, into
metallic sulphides, which pass into the slag in combination with sulphide
of sodium. The remaining arsenic is separated by the carbonate of
soda, in the form of arseniate of soda. If any charcoal fiills into the
crucible, it reduces arsenic from the arseniate of soda, whereby the anti-
mony is again rendered impure. (Liebig.) Hence a black-lead crucible
cannot be used ; such a crucible also reduces sodium, which then mixes
with the antimony. (Anthon, RepeH. 59, 240.) If the oonmiercial anti-
mony has been prepared with iron, and is consequently richer in iron, a
larger quantity of sulphide of antimony must be added in the first fusion,
that is to say, in proportion nearly corresponding to the iron, (4 parts of
sulphide of antimony and 4 parts of carbonate of soda, to 16 parts of
the antimony) ; in this case the loss of antimony is greater. As long as
iron is present, it is impossible to remove the arsenic by means of car-
bonate of soda. (Liebig, Ann, Pharm, 22, 5B\ Handw'&rierb. 1, 416.—*
See also Buchner, Repert. 51, 267.) — 2. Well washed powder of algaroth
is reduced with alkali and charcoad. By this means, all impurities from
the heavy metals are got rid of. Artus {J, pr. Chem, 8, 127), digests
1 part of finely powdered grey sulphide of antimony or glass of antimony,
with 2 parts of common salt, 3 parts of oil of vitriol and 2 parts of
water for 8 hours; then boils for an hour, and afterwards mixes the
liquid with water till a permanent precipitate begins to appear; then
filters; precipitates the powder of algaroth by adding more water;
washes it thoroughly; and fuses 100 parts of the dry compound with 80
parts of dry carbonate of soda and 20 parts of charcoal powder, for 15 or
20 minutes: 61 parts of pure antimony are thus obtainecL — 3. The purest
antimony is obtained from tartar-emetic, purified by repeated crystal-
lization. (Capitaine, /. Pharm. 25, 516; also J. pr, (Jhem, 18, 449.)
Purification from Anenic only, 1. Four parts of pounded commer-
cial antimony are mixed with 5 parts of nitre and 2 parts of dry car-
bonate of soda (without the latter, insoluble arseniate of antimonic oxide
would be formed), and the mixture projected into a red-hot crucible.
The mass remaining after the combustion (which takes place quietly),
is then pressed together, heated for half an hour at a higher temperature,
so that it may become pasty but not fused, and pressed down as often as
it swells up from evolution of gas. After this, it is taken out of the
crucible with the spatula, while still hot and soft, then reduced to
powder, and boiled for some time in water with frequent stirring. The
water, together with the finer powder, is then poured ofif; the coarser
powder crushed with a pestle, and boiled with a fresh quantity of water;
the two liquids with their deposits mixed; and the insoluble portion
freed by repeated subsidence and decantation, and, lastly, by washing on
a filter, from the alkaline solution which contains the alkaline arseniate
't
ANTIMONY. 321
and but a very small 'quantity of antimoniate. The washed acid antJ-
nioniate of potash is white ; but if it contains lead, which cannot be
removed by nitric acid, it has a yellow colour. It is then fused with
half its weight of cream of tartar at a moderate red heat, and the re-
sulting antimony containing potassium is pulverized and thrown into
wat^r, which removes the potassium and gives off pure hydrogen gas.
(Wohler, Pogg, 27, 628; also, Ann, Pharm. 5, 20.) 1 According to
C. Meyer, {Ann. Pharm. 66, 236; Centr, BlatL 1848, 828,) the use of
nitre is objectionable, because it gives rise to the formation of antimo-
niate of potash, which destroys the exactness of the process. Meyer
recommends a mixture of nitrate and carbonate of soda, whereby a mass
is obtained, which does not yield a trace of antimony to water. This
method is so exact,* that it may be used to separate antimonv from arsenic
in quantitative analysis; moreover, the antimony thus obtained is not
contaminated with potassium or sodium. IT This method is good, but
too expensive, and from the tedious washing of the antimoni&te of pot-
ash, difficult of execution on the large scale. Moreover, the whole of
the iron and copper, besides a small quantity of potassium, remains in
the antimony. (Liebig.J — Gbttling (Taschenb. 1780, 96) burned a mix-
ture of 16 parts of sulphide of antimony and 20 parts of nitre ; exhausted
the mass with hot water; fused the residue, after drying, with 16 parts
of cream of tartar; and obtained 9 parts of antimony, which probably was
nearly free from arsenic. — 2. One part of pulverized antimony, prepared
by the second method, is rapidly fused with half its weight of carbonate
of potash and the mass poured out ; the metal obtained is then crushed^
fused with one-fourth its weight of nitre ; again poured out; the metal
again crushed, and fused with one-third its weight of hvdrated anti-
monic acid; and lastly, the antimony, after being repulverized, is fused
with one-third its weight of carbonate of potash, and poured into the
mould. This method completely removes the arsenic. (Th. Martins,
Kastn, Arch. 24, 253.) — 3. If 32 parts of antimony rich in arsenic, are
fused with 4 parts of nitre, the slag contains a large quantity of arseniate
of potash; the resulting 30 parts of metal fused with 3 parts of nitre,
still yields a small quantity of arseniate of potash and 27 parts of metal;
this, if again fused with 2 parts of nitre, yields a slag, containing scarcely
anything but antimoniate of potash and metallic antimony, perfectly free
from arsenic. If carbonate of potash be used instead of nitre, the sepa-
ration of the arsenic is much more difficult. (J. A. Buchner, Mepert.
44, 246.) — 4. One part of antimony, prepared by the third method, is
heated with 1^ pt. of oil of vitriol in a porcelain basin, stirring con-
stantly as long as sulphurous acid gas continues to be evolved, and water
carefully added by small portions at a time, till a greyish-white, intu-
mescent mass is formed. This is mixed in a vessel made of antimony,
with from 0*2 to 0'4 pt. finely powdered fluorspar, and 0*4 to 0*8
pt. oil of vitriol (according to the quantity of arsenic present). The
whole is then heated, with constant stirring, as long as hydrofluoric acid
and fluoride of arsenic are given ofl*; the residue afterwards gradually
mixed with water; washed by decantation, till the wash- water ceases to
exhibit an acid reaction; and the remaining basic sulphate of antimonic
oxide reduced by fusion with half its weight of cream of tartar, in a
covered crucible. If a leaden vessel were used, antimony and arsenic
would be reduced together, and consequently the antimony obtained
would not be free from arsenic. (Duflos, Kcutn. Arch, 19, 56; also,
TOL. ir. Y
89S ANTIMOirr.
Schw, 60, a59 ; further, SAw. 62, 501 ; eee alao Baohner & Herberger,
RepeH.Z%y^%\\ 44,246.)
Te$U for ImpurUiea in Antimony, --^l. Sulphur, — The powdered
metftl, when heated with etrong hydrochloric acid, diaengagee ^ydrosal-
phurio acid. — 2. Potamum or oodtum.— The antimony appears more grey
than white, and loses its Ivstre on exposure to the air. Its powder hais
an alkaline taste, reddens moist tarmeric paper, and eTolres hydrogen
gas when pat under water, giying up alkali to the liquid.-*^, iirs^nic.-—
The metal, when fused in the air, emits a garlic odour. If its powder
be detonated with about \ pt. nitre, and the resulting mass treated with
water, a filtrate is obtained, which contains arseniate and antimoniate of
potash, so that, when supersaturated with hydrochloric acid and rapidly
saturated with hydrosulphuric acid gas, it first gives a yellowish-red pre-
cipitate of pentasulphide of antimony, and then if rapidly filtered and
preserred in a close vessel, gradually deposits a yellow precipitate of
pentasulphide of arsenic. The antimony ignited with an equal weight of
cream of tartar in a covered crucible, yields an alloy of potassium,
arsenic, and antimony, which, if reduced to powder under water, evolves
arseniuretted hydrogen, recognisable by its depositing brown metallic
arsenic on ignition (p. 265). — 4. Lead, — The powdered metal boiled with
nitric acid nearly to dryness, and then treated with water, yields a filtrate
which contains nitrate of lead, and is consequently precipitated by sul-
phuric acid. When the quantity of lead is large, a solution of antimony
in aqua-regia deposits crystalline needles of chloride of load on cooling.
««If the antimony contains sulphur besides the leady the lead remains
undissolved in the form of sulphate, on treating the metal with nitric
acid. If the antimonio oxide in the residue is then dissolved out by
warm hydrosulphate of ammonia,, black sulphide of lead remains behind,
and if iron is present, black sulphide of iron also.— 5. Iran, — The
finely divided metal ignited with 8 times its weight of nitre, and washed
with boiling water, leaves a yellowish residue, trom which boiling dilate
hydrochloric acid separates ferric oxide, which may be detected by
ferrocyanide of potassium, &c. — 6. Copper, — When tne lead has been
precipitated from the nitric acid solution by sulphuric acid, according to
the method above given, the cuprio oxide remains dissolved, and may be
recognized by its behaviour with hydrosulphurio acid, ferrocyanide of
potassium, ammonia, or polished iron.
Pure antimony fuses before the blowpipe on charcoal, forming a
shining globule which bums completely away wiUi evolution of inodorous
vapours, and becomes covered, on cooling, with beautiful white needles of
antimonic oxide. Impure antimony, on the contrary, exhales a garlic
odour, especially at the commencement; becomes covered with a slaff of
sulphide of iron; has a dull surfi&oe; ceases to bum as soon as the blow-
pipe flame is withdrawn; and yields a yellow oxide. (Liebig.) Pure
antimony, after fasion before the blowpipe, should solidify in a smooth
globule having a silvery lustre. (Capitaine.) A solution of antimony
in aqua-regia should give a yellowish-red precipitate with hydrosulphate
of ammonia, perfectly soluble in excess of the precipitant. If a black
residue is left, it must consist of sulphide of lead, iron, or copper. (H. Bose.)
Propertiei, — Crystalline system the rhombohedral. Primary form an
acute rhombohedron. Fig, 151; t^ : r*=: 87° 39': also an obtase rhom^
bohedron (Fig. 141) the axis of which is half as long as that of the acute
rhombohearon, and in which, according to Mobs, r* : r^s? 117° 15'.
SUBOXIDE OF ANTIMONT. 323
(Breithanpt, Sdiw, 52^ 1 69.) When fused antimony is allowed to solidify
partiaUj and the fused portion then poured off> small acnte rhombs
approaching the cube, are obtained {Fig. 151) r^ :if^:=. 87° 28', with one
rery distinct plane of cleavage parallel to p {Fig, 152), and three less
brilliant, which cut off the vertical edges, and consequently tend to
produce an obtuse rhombohedron {e.g, corresponding to the truncation-
faces in Fig, 145). The angle between the principal cleavage-plane
parallel to p, and one of the other threes 142° 5'. (Marx, Schw, 59,
211.) H. Rose {Pogg, 15, 454) and Eisner (J,pr, Okem. 20, 71) likewise
obtained distinct rhombohedrons. Hauy formerly supposed that he had
discovered in antimony the 4 cleavage-planes of the regular octohedron
and the cleavage-planes of the rhombio-dodecahedron« Sp. gr. =
6-7006 (Karsten^, 6*702 (Brisson), 6712 (Hatohett), 6-715 at 16°
(Marchand & Scheerer), 6-728 (Bbckmann), 6*860 (Berraian). If from
pure antimony of specific gravity 6*715, a cylinder is filed so as exactly
to fit a diamond mortar, and is then submitted therein to a pressure of
150,000 lbs., it is first crushed to powder, and afterwards re-eonverted Into
a perfectly solid mass which has a specific gravity of 6*714. Similarly,
commercial antimony, of specific gravity 6-696^ after being crushed and
resolidified in a diamond mortar, has a specific gravity of 6*693, Hence
antimony has the same specific gravity whether in the crystallised or in
the compressed state. (Marchand & Th. Scheerer, J. pr. Chem. 21 y 207.)
Not very hard ; very brittle, and easily reduced to powder. Tin-white,
highly lustrous. Fuses at 432°, according to Dalton; at 518°, according
to Guyton-Morveau. The pur^r the antimony, the more easily does it
fuse. (Capitaine.) It does not dilate on cooling. (Marx, Sekw, 58, 464.)
Volatilizes out of contact of air only at very elevated temperatures, but in
a current of air, much less heat is required. Antimony covered with a
flux loses less than xqVo ^^ ^^ weight In the strongest white heat ; but,
in a current of hydrogen gas, it n^y be distilled at a white heat. (Lleblg.
ffandworterbuch, )
Oompwinds pf AtUimony*
AKTmomr and Oxtobn.
A. BuBoxiDB OF AKTmomr. BbOt
1. In moist air, antimony becomes covered with a thin film of sub-
oxide, and is thereby rendered dull and of a darker grey colour. —
2. When a bar of antimony is used for the positive electrode in the
decomposition of water, it becomes covered with a lead-grey film, which
appears blackish-grey after drving. To obtain the suboxide in larger
quantity, powdered antimony is immersed in water, and connected by a
platinum wire with the positive nolo of a battery ; and the bluish-grey
flocculent powder which is formea, is separated, nrom time to time, nrom
the rest of the antimony, by levigation. The suboxide when dry is
blackish-ffrey, and cannot be made to take the metallic lustre by pressure
with the burnisher. When treated with hydrochloric acid, it is resolved
into antimonic oxide, which dissolves, and a residue of the metal. (Ber-
xelius.) Regarded by Proust as a mixture of metal and oxide.
y2
324 ANTIMONY
B. Antimonic Oxide. SbO'.
Teroxide of Antimony^ Protoxyde cTAntimoine, — Found Datire as
White AiUimony Ore (Weiss-spiessglanzerz) or Flowers of Antimony.
(Antimonbluthe,)
FornuUum. — I. When antimony is heated in the air till it boib, it
takes fire and bums with a bright bluish- white flame, and at a moderate
red-heat with a reddish light, — yielding antimonic oxide, which condenses
on cold bodies in the form of Flowers of Antimony, Flores Antimanii
aryentei, Nix Siihii. When strongly Ignited antimony is thrown on
the ground, it separates into small globules which continue to born.
Antimony heated to strong redness on charcoal before the blowpipe
and then left to cool quietly, becomes covered with brilliant needles of
antimonic oxide. If the antimony contains but a trace of arsenic, it emits
the garlic-odour in burning. According to Liebig and Capitaine, it does
not emit any odour when pure; but according to Pfftff, Wohler, and
Martins, it evolves a peculiar odour totaUy dinerent from that of garlic,
and compared by Martius to that of nitric acid. — 2. When aqueous
vapour is passed over antimony at a strong red-heat, hydrogen gas is set
free and crystallized antimonic oxide formed. (Berielius, Regnault, Ann.
Chim. Phys. 62, 362.) The author did not succeed in evolving hydrogen
by boiling antimony with strong hydrochloric acid. — 3. In hot oil of
vitriol, antimony is conrerted into sulphate of antimonic oxide, with
evolution of sn^hurous acid gajs. — 4. When the metal is treated with
nitric acid, nitric oxide is disengaged, and a mixture of basic nitrate of
antimonic oxide and antimonious or antimonic acid is formed. At the
temperature of 20°, nitric acid perfectly free from nitrous acid does not
attack antimony at any degree of concentration; only the strongest acid
acting on it, slightly and without effervescence. Aqna-regia is like-
wise without action, when so dilnte and cool that the two acids are not
decomposed; but the addition of a few drops of nitrons acid induces the
act ox combination, which afterwards goes on by itself; a current of
chlorine, on the contrary, does not set up the action. (Millon.) The
colder and more dilute the nitric acid, the greater is the quantity of
nitrate of antimonic oxide formed and the smaller that of the antimo-
nious acid; but with the basic nitrate of antimonic oxide, a large quantity
of metallic antimony remains mixed, and is left behind on dissolving the
oxide in hydrochloric acid. That antimonious acid (antimoniate of
antimonic oxide) and not antimonic acid is produced by the stronger
action of nitric acid, Is proved by the following fa^t. Wnen a mixture
of antimonic acid with pure antimonic oxide is boiled with cream of
tartar and water, a turbid solution is obtained; but on substituting anti-
monious acid for the antimonic acid, a clear solution is formed, which first
yields crystals of tartar emetic and then leaves a gummy residue. The
powder obtained by acting on antimony with nitric acid exhibits the
last-mentioned character. (H. Rose, Pogg. 53, 161.) — ^5. By fusing
antimony with oxide of l^, antimonic oxide and metallic lead are
formed. (Liebig.) — 6. Antimonious or antimonic acid is converted into
antimonic oxide by ignition with antimony or sulphide of antimony.
PreparoJtion,'—!. By burning antimony in an inclined cmcible ex-
posed to the air, and passing the ascending vapours through earthen or
wide glass tubes, wherein the flowers of antimony are deposited. The
ANTFMONIG OXIDE, 325
necks of broken retorts or receivers make convenient tabes for this
purpose. If the antimony is heated to redness in a wide crucible inclined
and loosely covered^ the conducting tube may be dispensed with, as the
oxide sublimes in the cooler parts of the cmcible, and even forms brilliant
needles: these must be removed from time to time. By this process^
8 parts of metal yield more than 9 parts of oxide. (Liebig.) The oxide
obtained by combustion contains however antimonions acid^ which ren«
ders it difficultly fusible. (H. Rose.)— 2. Oxy-chloride of antimony is
digested with an aqueous solution of carbonate of potash or soda^ and the
residue thoroughly washed: 1 part of carbonate of soda to 20 parts
of powder of algarotii. This process yields a pure oxide free from any
higher oxygen-compound. (H. Rose.) — 3. The sulphate of antimonio
oxide, obtained by boiling powdered antimony with oil of vitriol to
dryness, may be treated m a similar manner. By mere boiling with
water, the acid is less completely removed; nevertheless, the greater part
may be separated by water, so as to render a smaller quantity of alkali
sufficient. — 4. Pulverized antimony is boiled with moderately strong
nitric acid till it is converted into a white powder, which is then freed
from nitric acid by repeated boiling with pure water. The white powder
is a mixture of basic nitrate of antimonic oxide, sometimes with antimony,
sometimes with antimonions acid, and sometimes with both together
(p. 324). The exact temperature and strength of the nitric acid necessary
to convert the whole of the antimony into oxide without any admixture
of antimonions acid, cannot be determined. At a moderate heat, more
than •}-, — ^by boiling, -| of the antimony are converted into antimonions
acid. But 1 part of powdered antimony digested with 2 parts of aqna-
regia and 4 parts of water yields 96*6 per cent, of antimonic oxide after
washing. (Brandos, iT. Br. Arch. 21, 156.) — 5. A mixture of 74 parts of
antimony, 39 parts of nitre, and 34 parts of bisulphate of potash is pro-
jected into a red-hot crucible, the ingredients being added rapidly one
after the other; the covered crucible is then kept red-hot for some time;
and the resulting mass, in which needles of antimonic oxide are found^ is
boiled, first with pure water, then with water containing sulphuric acid^ and
lastly a^ain with pure water. Any arsenic that may be present is
dissolved in the first wash-water, but iron remains behind with the oxide.
(Preuss, Ann, Fharm. 31, 197.) — 6. Sulphide of antimony is roasted
thoroughly, and the resulting antimonions acid fused with m>m t^Xo-^
its weight of sulphide of antimony. (Berzelins.) With even a small
excess of sulphide of antimony, oxysulphide of antimony ISpiesagUmZ'
glasy vid. seq.) is formed, but with a small deficiency of tne sulphide,
antimonions acid remains undecomposed and renders the glass turbid;
when the exact proportions are observed, the glass is colourless and
transparent.
Ii the antimonic oxide prepared by either of these processes contains
a higher compound of the metal with oxygen, it evolves sulphurous acid
when fused with sulphide of antimony in a tube through which hydrogen
(or carbonic acid) gas is passed. (H. Rose.) Moreover, when dissolved in
moderately dilute hydrochloric^ acid or in a hot solution of cream of tartar,
it leaves a residue.
Properties. — Dimorphous.— «. The native oxide belongs to the right
prismatic system {Fig. 65) «* : w = 136'' 58'; i : i = 70^ 32'; cleavage
parallel to u. Sp. gr. = 5-56. (Mohs.) Hardness, equal to that of rock-
salt. Colourless, translucent, with diamond-lustre, the (-fiace having a
326 ANTIMONY.
pearlr Instils. By the first method, also^ antimonic oxide is obtained in
rerj Drilliant needles of the same fbrm^ having, according to Boullay, a
specific gravity of 5*778. — 6. Sometimes, however, antimonic oxide sub-
limes in regular octohedrokis instead of needles. (Bonsdorff & Mitscherlich^
Pogg. 15, 453; Wshler, H. Rose, Pogg, 26, 180.) If a few ounces of
antimony are heated till they begin to burn, and then left to cool slowly,
needles are obtained having octohedrons adhering to them. (Berzelius.)
[Hence it would appear that antimony takes the octohedral form, when it
sublimes at a comparatively low temperature.] According to Mltscher-
lich {J, pr, Ckem, 19, 455; also Ann. Ghim, rhys, 73, 394), these octo-
hedrons may likewise be obtained in the wet way. From a eolation of
antimonic oxide in boiling soda, octohedrons separate on cooling the liquid
ill close vessels. A solution of tartar-emetic decomposed by ammonia,
soda, or potash (which latter must not be in excess), or by alkaline
carbonates, yields microscopic octohedrons after some time. The floccu-
lent precipitate produced by pure alkalis or alkaline carbonates in acid
hydrochlorate of antimonic oxide, is converted, sometimes during washing,
sometimes on drying, into small octohedrons; but if the boiling acid
hydrochlorate of antimonic oxide be added to a boiling solution of carbo-
nate of soda, the oxide separates in the form of prisms. (Mitscherlich.)
Antimonic oxide, by whatever method it may have been prepared, turns
yellow every time it is heated, and fuses even at a low red-heat, forming
a yellowish or greyish liquid, which on cooling solidifies to a white
asbestos-like mass, having a silky lustre. At a higher temperature, it
volatilises— €Ven in a glass tube, provided the air is excluded— and
sublimes in needles. It acts as an emetic.
CalculAtion. Berzelius. J. Davy. P^qbI.
Sb ............ 129 .... 84-31 84-319 .... 85 .... 81-5
30...». 24 .... 15-69 .... 15-681 .... 15 185
SbO* 153 .... 100-00 Z 100-000 Z. 100 Z 1000
(6b^0* a 2 . 806-46 + 8 . 100 = 19129. BeiveUiis.)
3ee(mp&Bition$, — By potassium at ia gentle heat, yielding metallic
antimony, with evolution of light and heat. By charcoal it is reduced to
metallic antimony ; before the blowpipe on charcoal, it is reduced maoh
more easily than antimonious or antimonic acid, and imparts a green
tinge to the flame. (Benselius.) — By carbonic oxide gas at ^a red heat,
to melallic antimony. (Gmelin.) — Similarly by hydrogen eas (Liebig) ;
by fused cyanide of potassium, the products being meUulio antimony
and cyanate of potash. (Liebig.) — By fusion with a small quantity
of sulphur, sulphurous acid is evolved, and glass of antimony formed ;
bat with a larger quantity of sulphur, sulphide of antimony is produced.
(Proust.)
2SbO» + 9S = 2SbS» + 3SO«.
By bihydrostilphate of ammonia, it is first converted into yellow saffron,
and then into brownish-red kermes, part of which dissolves. (Berzelius.)
— When it is boiled with sulphur and solution of caustic soda, sulph-
aAtimoniate of sodium and antimoniate of soda are formed^ (Mitscherlich.)
— It is not altered by itision with antimony. (Proust.)
Comhinaiiona, — a, Antimonic oxide does not appear to form a definite
hydr&te, but, according to Berzelius, it is sparingly Soluble in water.
ANTIMONIC SALTS. 327
It dissolres sparmdy in water, especially in boiling water, without sepa-
rating as the liquid cools. The solution is coloured yellow by hydro^
sulphuric acid, and gires an orange-coloured precipitate, either after
long standing, or immediately on boiling, or on the addition of hydro-
chloric acid. Ammonia decolorizes the solution treated with hydrosul-
phuric acid. (Gapitaine.)
IT According to Fresenlus, the following method yields Hydrate of
Antimonic Oxiae, A solution of recently precipitated tersulphide of anti-
mony in caustic potash is heated to the boihng point, and solution of
sulphate of copper added, till a portion of the liquid, when mixed with
acids, gives a pure white precipitate without any tinge of orange.
The liquid is then filtered irom the sulphide of copper, and treated
with acetic acid as long as a precipitate is formed; tho precipitate is
lastly collected on a filter, wasned, and dried. When gently heated, it
lost 10-90....11-20 per cent, of water, corresponding to the formula
SbO»+2Aq.
Cftlculatioii. ftetetAoA.
SbO» » 153 .... 89-474 89-95
gHO 18 .... 10-626 U-06
SbO« + 2Aq 171 .... 100*000 ZZ 101*00
{h. Schaffndr, Ann. Pharw. 51, 168.) IT
5. With acids, forming the Salts of Antimonic Oxide, or Anti-
monic Salts. — These salts are obtained by bringing the acid in contact,
either with the metal or with pure antimonic oxide, or with a sub-
stance containing antimonic oxide, such as the glass of antimony or
antimonial saffron. They are colourless or yellowish, and have a faint
metallic taste and strong emetic properties. They lose their acid at a
red heat, if it be rolatile. When mixed with carbonate of soda and fused
on charcoal before the blowpipe, they yield metallic antimony. From
their solution in water or acids, e. y., from acid hydrochlorate of anti-
monic oxide, the whole of the antimony is precipitated in the form of a
black powder, by zinc, cadmium, tin, lead, iron, or cobalt; bismuth and
copper precipitate it but imperfectly. (Fischer, Pogg, 8, 499 ; 9, 264 ;
N, Br, Arch, 11, 120.) The precipitated antimony takes fire when
dried in the air, even at a gentle heat. (Liebig.) Copper becomes
covered with a metallic, violet-coloured film in a smution of acid hydro-
chlorate of antimonic oxide diluted 200,000 times; also in a solution of
tartar-emetic, after the addition of a small quantity of hydrochloric
acid. (Reinsch, J,pr, Chem, 24, 247.) — Hydrosulphuric acid precipitates
yellowish-red tersulphide of antimony from solutions of antimonic salts,
eyen when they contain a large excess of acid, — according to Pfaff, in
solutions of 1 part of salt in 20,000 parts of water. — One part of tartar-
emetic dissolved in 10,000 parts of water and 5,000 parts of hydrochloric
acid gives a slight cloudiness with hydrosulphuric acid ; with 1 5,000 pts.
of water and 7,500 pts. of hydrochloric acid, still a yellow coloar ; with
80,000 pts. of water and 15,000 pts. of actd, no ^4sible effect is pro*
duced. (Reinsch, J, pr, Chem, 13, ld2.)^Alkaline hydrosulphates
produce the same yellowish-red precipitate; but if added in excess, they
redissolve it, especially if heat oe applied, or if an alkaline hydrosuL
phite is mixed with the precipitate, or if finely powdered sulphur is
added to it. (H. Rose.)-^Dilute solutions of antimonic salts give with
hyposulphite of soda, on the addition of a small quantity of hydro*
chloric acid; a yellow precipitate, which gradually changes almost to
328 ANTIMONY.
cinnabaivred (the colour of kermeB). (Himly.) — The affinity of antimonio
oxide for acidis is but feeble ; the neutral compounds, unless mixed with
tartaric acid, are frequently resolved by excess of water, into dilute acid
holding a small quantity of antimonic oxide in solution, and a basic salt
which falls to the bottom. The acid when supersaturated with water,
appears to lose its affinity for the antimonic oxide; accordingly, the larger
the quantity of water added, the more completely is the oxide thrown
down; it combines, however, with a small portion of the acid; and as
the resulting basic salt is, for the most part, slightly soluble in water, the
quantity of the precipitate is decreased by too large an excess of water.
— Ammonia precipitates the oxide completely, in bulky white flakes,
which become dense after a while, and are not soluble in excess of the pre-
cipitant. — Potash produces the same flocculent precipitate, which, however,
on the addition of a slight excess of potash, forms crystalline grains of
a compound of antimonic oxide and potash on the sides of the vessel,
and with a larger excess dissolves entirely. — Carbonate of ammonia,
potash, or soda, and likewise the bicarbonates of these bases, completely
Srecipitate the oxide in voluminous flakes, which gradually increase in
ensity; they are slightly soluble in excess of the monocarbonate of
potash only ; the precipitation is attended with evolution of carbonic acid.
(H. Rose.) — The carbonates of baryta, lime, and magnesia also precipitate
antimonic oxide at ordinary temperatures. (Demar^ay.) — Phosphate of soda
precipitates white flakes, but leaves part of the oxide in solution. (H. Rose.)
— Oxalic acid produces a very bulky precipitate, and after long standing,
separates the whole of the oxide ; with an excess of oxalic acid, the
precipitate does not appear till after some time, but on longer standing
the separation is likewise complete. (H. Rose.) — Ferrocyanide of potas-
sium gives a white precipitate, insoluble in hydrochloric acid; tincture
of galls, a yellowish-white precipitate. Ferricyanide of potassium does
not aflect the salts of antimonic oxide. — All antimonic salts which are
Insoluble in water, dissolve in hydrochloric acid, and then give the same
reactions.
c. With Alkalis-^-<f. with Sulphide of Antimony.
C. Antimonious Acid. SbO^
AfUimonige Saure, Acide antirrumieux, Deutoxyde iTAfUimoine.
Formation. — 1 . When antimony or sulphide of antimony is heated
for some time in contact with the air; also when antimonic oxide is
heated in the air. According to Berzelius, antimonic oxide, when finely
divided, burns like tinder, till it is converted into antimonious acid.
(Berzelius.) — 2. When antimony is fused with sulphate of potash, anti-
monite of potash, sulphide of antimony, and sulphide of potassium are
formed. (Liebig.) — 3. By igniting antimonic acid. (Berzelius.)
Preparation, — 1. By roasting sulphide of antimony as completely as
possible. (Antimony-ash, Spiessglamasche.) — 2. By igniting antimonic
acid or nitrate of antimonic oxide.
Properties, — ^White powder, which turns yellow every time it is
heated; emits a vivid li^ht in the blowpipe flame without fusing, and in
the inner flame is slowly dissipated, but is otherwise fixed in the fire.
(Berzelius.) Sp. gr. = 6-6952 (Karsten). Reddens litmus-paper when
moistened. (H. Rose.)
ANTIMONIOUS ACID. 329
fienelius. Thorn- Th^-
Calculation. (1) (2) son. nard. Proust.
8b 129 .... 80-12 .... 78-2 .... 80*127 .... 80-84 .... 80 .... 77
40 32 .... 19-88 .... 21-8 .... 19-873 .... 19-16 .... 20 .... 23
SbO*.... 161 .... 100-00 .... 100-0 .... 100-000 .... 100-00 .... 100 .... 100
Or:
SbO» 153 .... 47-52
SbO» 169 .... 52-48
SbO»,SbO« 322 Z. 10000
(SbS0« = 2 . 806-45 + 4 . 100 = 2012*9. BerzeUas.)
It may aJso be regarded as antimoniate of antimonic oxide =SbO^
SbO'. Wben antimonioas acid is fused with excess of carbonate of soda^
boiling water, if added in large quantity, chiefly dissolves out from the
mass, a compound of antimonic oxide and soda, together with a small
quantity of antimoniate of soda, leaving antimoniate of soda with a
small quantity of the compound of antimonic oxide and soda undissolved.
(Mitscnerlich^ J» pr, Ghem. ID, 457.)
Decompositions. — ^When gently heated with potassium or sodium,
antimonious acid is reduced to the metallic state, with incandescence.
(6ay-Lu5sac & Thenard.) — It is likewise reduced to the metallic state
by ignition with charcoal. — On charcoal in the inner blowpipe-flame the
reduction is very difficult, because the reduced antimony volatilizes,
and covers the charcoal all round with freshly formed oxide: the
addition of carbonate of soda is indispensable to the formation of
metallic globules. (Berzelius.) — By cyanide of potassium at a low red
heat, the products being antimony and cyanate of potash. (Liebig.)
When a mixture of antimonious acid and finely divided antimony
is heated to redness, antimonic oxide is produced. (Proust.) dSbO^
•f Sb=4SbO'. — When antimonious acid is gently heated with iodide
of potassium, iodine is evolved, and a compound of antimonic oxide
and potash is formed. (Capitaine.) — ^When heated with a small quantity
of sulphur, it yields sulphurous acid and glass of antimony; a larger
proportion of sulphur gives rise to the formation of sulpnurous acid
and sulphide of antimony. (Proust.) SbO*+5S=SbS»+2SO».— By fusion
with a small quantity of sulphide of antimony, it yields antimonic
oxide, with evolution of sulphurous acid; with a larger quantity of
the sulphide, oxy-sulphide of antimony is formed: 9SbO^+SbS^=
10SbO^+3SO^ — Antimonious acid is not afiected by a cold solution of
bihydrosulphate of potash; a boiling solution, on the contrary, dissolves it
with disengagement of hydrosulphuric acid, and acids added to the solu-
tion, precipitate tetrasulphide of antimony. (Berzelius.)
Combinations. — a. With water. — «. Hydrateop Antimonious Acid.
— Prepared by decomposing an aqueous solution of antimonite of potash
or soda by an acid. — White flakes, which are insoluble in water, but
redden litmus paper, even after the most prolonged washing with water.
When heated, it gives off 5-26 per cent, of water, free from acid,
(Berzelius.)
Calculation. Berzelina.
SbO< 161 .... 94-71 .... 94-74
HO 9 .... 5-29 .... 5-26
HO,SbO* 170 .... 100-00 .... 100-00
330 ANTIIfONT.
0. Solution of AtUimoniotu ilekl.— -The acid dissolTes in boiling
water somewhat more readily than antimonic oxidej hydrosulphuric acid
colours the solution yellow, bnt the colour disappears on the addition of
ammonia. (Capitaine.)
b, Antimonious acid is sparingly dissolved by a few acids; hydro-
sulphuric acid added to these solutions, throws down an orange-yellow
precipitate.
c. With Salifiable Bases, it fonns salts called Antimonites. When
ignited with alkaline carbonates it expels the carbonic acid. The
alkaline antimonites are colourless; they are decomposed by nitric and
other acids, which remove the base and leave the antimonious acid
undissolved. The latter is not perceptibly dissolved by the excess of
acid; the p)recipitate is coloured orange-yellow by hydrosulphuric acid,
and, when digested with iron and hydrochloric acid, deposits antimony in
the form of a black powder. Some antimonites, when strongly heated
become incandescent (I. 107), after which they are scarcely decomposed
by acids. (Berzelius.) The alkaline antimonites do not exhibit this
incandescence; they are decomposed by nitric acid even after ignition.
If antimonious acid is regarded as antimoniate of antimonic oxide, ittf
salts must consist of an antimoniate mixed with a compound of antimonic
oxide and the same base.
D. Antimonic Acid. SbO*.
Antimomaure, Acide Antimoniqtis, TrUoxj/de (FAntimoine*
Antimony-ochre appears sometimes to contain hydrate of antimonious
acid, and sometimes hydrate of antimonic acid.
Formation, — 1 . By heating the metal or one of Its lower oxides with
nitric acid. According to Bourson (Ann. Chim, Pkys, 70, 110; also
J, pr. Ckem. 17, 238), finely divided antimony, as it Is obtained by
precipitation with zinc, is completely converted into antimonic acid by
digestion with nitric acid, either cold or hot, concentrated or dilute;
and the resulting antimonic acid, after washing, evolves oxygen gas on
ignition, without any admixture of nitrous acid. According to H. Rose,
though the antimony in this state is strongly attacked by nitric acid,
only a portion of it is converted into antimonic acid, even by boiling; and
the nitrate of antimonic oxide formed at the same time is completely
changed into antimonic acid, only by repeated^evaporation to dryness with
fresh quantities of nitric acid. — 2. By deflagrating antimony with nitre.-—
3. By heating it with red oxide of mercury.
JPrfparation, — 1. Antimonic acid is prepared by evaporating a solution
of antimony in aqua-regia to dryness, treating the residue with strong
nitric acid, and heating the mixture till the whole of the nitric acid is
expelled, but not to redness. (Berzelius.) The Bezoardicum minerah
was formerly prepared by mixing butter of antimony with strong
nitric »eid, evaporating, and repeatedly distilling off the nitric acid
2. Powdered antimony is boiled with nitric acid, and the residue — which
tsonsists of hydrated an^monie acid and basic nitrate of antimonic oxide
— is heated nearly to redness. (Berzelius.) — 3. Powdered antimony is
heated with ted oxide of mercury till the green antimoniate of mercuric
oxide, which is formed at first with emission of light and heat, is con-
verted into yellow antimonic acid. (Berzelius.)— 4, Hydrate •f anti-
monic acid Is heated not quite to redness. (Berielius.)
ANTIMONIC ACID. 331
Propertie8,-'^'P\BA^ lemon-yellow Bub6tano0| which beoomes datker
eveiy time it is heated. Tasteless. (Berzelius.) Reddens moistened
litmiiB paper. (H» Rose.) 6p. gr. = 6'525. (Boallay.)
Berzeliiu.
Calculation. (1) (2) Proust. iThenard. Thomson.
Sb 129 .... 76*33 .... 72*9 .... 76*34 .... 77 .... 68 .... 7333
50 40 .... 23-67 .... 27*1 .... 23*66 .... 23 .... 32 .... 26*67
SbO* .... 169 .... 10000 .... 100-0 .... 100*00 .... 100 .... 100 .... 100*00
(Sb^O* » 2 . 806*46 + 5 . 100 » 2112*9. BeneUus.)
Decampontions. — Antimonic acid is resolved at a red heat into oxygen
gas and antimonious acid. (Berzeliiis.) When heated with a small
quantity of sulphur^ it yields sulphurous acid and antimonic oxide; with
more sulphuri the products are sulphurous acid and sulphide of antimony.
SbO* + S = 8bO» + SO«j
and t 2SbO« + 118= 2SbS» + 580».
By ignition with sulphide of lead, copper^ or silver, it likewise disengages
sulphurous acid and is converted into antimonic oxide. (Rammelsoergi
Fogg, 52, 241.) With alkaline bihydrosulphates, it behaves like anti-
monious acid. (Berzelius.)
Comlinations, — a. With Water. — «. Hydrate of Amtimonic Acid.—-
Ifateria perlata Kerkringii, Magigterium Antimonii diaphoretiei, Sulphur
fixatum Stibii. — 1. A mixture of 1 part of antimony (or sulphid!e of
antimony) and 4 parts of nitre is projected by small portions at a time
into a red-hot crucible; the heat raised after the deflagration has ceased ;
the pounded mass exhausted with water; the filtrate, which contains
antimoniate of potash, treated with excess of nitric acid; and the precipi-
tated hydrate thrown on a filter and thoroughly washed with water.
(Berzelius.) The biantimoniate of potash, which forms the residue after
exhaustion with water, may likewise be converted into hydrate of
antimotaic acid, by boiling with dilute nitric acid and washing with water.
—2. Pentachloride of antimony is decomposed by water and the precipi-
tated hydrate washed with water. After the hydrochloric acid solution
is washed away, the hydrate difiuses itself through the wash-water in
so finely divided a state, that it passes through the filter and renders the
liquid opalescent.
IF The acid obtained by the second method, or in combination, by
fusing ordinary antimoniate of potash with excess of alkali, is regarded
by Fremy as a modification of antimonic acid, and distinguished by
the name of Meta- antimonic add. Meta- antimonic acid is bibasic, and
dissolves slowly in ammonia, whereas the ordinary variety is quite
insoluble in that menstruum ; it likewise dissolves more easily in acids,
and is perfectly soluble in a large quantity of water, from which it
is again precipitated by acids. But from the facility with which it passes
into the ordinary variety, there is great difficulty in accurately distin-
guishing the two acids. (E. Fremy, Ann, Ckim. Fuy$. 3, 23, 407.) IT
Fine white powder, which reddens litmus, and is insoluble in water:
it gives off its water below a red heat. (Berzelius.)
escalation. Beneliw.
SbO« 169 .... 94*94 94*91
HO 9 .... 5*06 5*09
HO,SbO* 178 .... 10000 ~, 100*00
332 ANTIMONY.
H According to Fremy, the hjdrate of the ordinary acid contains
21*7 per cent, of water (calculated 21*0) which gives the formnla
ShO' + 5HO; and the hydrate of meta-antimonic acid, 17*1 (calculated
17*5) per cent, corresponding to the formula SbO*+4HO. IT
ff. SoltUion of Antimonic Acid, — ^The hydrafce dissolves sparingly in
water, forming a solution which behaves with hydrosulphuric acid like
the solution of antimonious acid. (Capitaine.)
b, Antimonic acid is slightly soluble in hydrochloric and tartaric acid.
c. With Salifiable Bases, antimonic acid forms salts called Antimo-
KIATES. From the alkaline carbonates it expels carbonic acid on ignition,
but not from their boiling aqueous solutions. Through the researches of
Berzelius, we are acquainted with compounds of 1 atom of base with 1 and
with 2 atoms of antimonic acid; besides these, according to Fremy {Compt,
rend, 10, 187), there exist salts which contain 1 atom of acid- to 1^ and to
2 atoms of base, and are formed by igniting alkaline niono-antimoniates
with excess of alkali. The antimoniates of the alkalis and earths are
colourless. Only those of the more soluble alkalis are soluble in water.
The antimoniates are decomposed even by weak acids. In these decom-
positions, the stronger acids, such as sulphuric or nitric acid, separate
hydrate of antimonic oxide; carbonic acid, on the contrary, throws down
a bi-antimoniate from a solution of the monobasic salt. The hydrate of
antimonic acid thus precipitated is dissolved by excess of hydrochloric or
tartaric acid on the application of heat, but not by any of the other acids;
when digested with hydrochloric acid and iron, it yields a dark-coloured,
easily fusible precipitate of metallic antimony, and turns orange-yellow
when treated with hydrosulphuric acid. Strong hydrochloric acid dis-
solves most of the antimoniates. From the solution, zinc precipitates a
black powder, consisting of metallic antimony; hydrosulphuric acid
throws down an orange-yellow precipitate (provided the base does not
also form a precipitate of a peculiar colour) easily soluble in hydro-
sulphate of ammonia. From toe compounds of antimonic acid with the
heavy metallic oxides, bihydrosulphate of ammonia withdraws the
antimonic acid, and the filtrate, when treated with an acid, yields penta-
sulphide of antimony. Many antimoniates, especially those of zinc,
cobalt, and copper, after all their water has been driven oJBT at a red-heat,
become incandescent without further loss of weight; they then assume a
much lighter colour, and are afterwards but slightly, if at all, decomposed
by acids. (Berzelius.)
Antimony and Hydrogen.
A. Solid Antimonide of Hydrogen? — ^When antimony is made to
conduct the negative electricity of a yoltaic battery into water, a
brownish-black substance is slowly formed. (Ruhland, iSchw. 15, 480.)
B. Antimoniuretted hydrogen Gas. — Discovered by L. Thomson. —
Formation, 1. This gas is evolved on dissolving antimonide of zinc in dilute
acids. — 2. When zinc mixed with antimonic oxide, antimonious acid,
or antimonic acid is dissolved in dilute acids. (Thomson.) Under these
circumstances, a small portion only of the antimony passes ofi" in the
form of antimoniuretted hydrogen, the greater part remaining behind in
the liquid, in the form'of black pulverulent metallic antimony. (Jacquelain,
Compt, rend. 16, 31.) If iron is substituted for the zinc, the hydrogen
ANTIMONIU RETTED HYDROGEN. 333
evolv<;d is free from antimony. (Dupasqaier, Compt rend, 14, 514.)
Antimonido of potaasium likewise evolves pure hydrogen gas when pat
into water. (Capitaine.)
Preparation. — 1. By dissolving an alloy of zinc and antimony in
dilute snlphuric or hydrochloric acid. Thompson melts together equal
parts of zinc and antimony, and thereby forms an alloy which ^ wnen
treated with dilate sulphuric acid, yields a pare gas, unmixed with free
hydrogen. — Lassaigne fuses 3 parts of zinc with 2 parts of antimony,
and obtains a gas containing not more than 2 per cent, of free hydrogen.
Capitaine treats a mixture of 2 parts of zinc and 1 part of antimony
with dilate sulphuric acid, in which antimonic oxide is diffused. A. Vogel
treats the same alloy with hydrochloric acid, and obtains a ^as mixed
with a large quantity of free hydrogen. — With equal parts of zinc and
antimony, the evolution of gas proceeds slowly, but the gas is nearly
pure. (Capitaine.) — With 2 parts of zinc to 3 parts of antimony, the
evolution of gas is very feeble, and soon ceases altogether. (Lassaigne.)
—2. By dissolving zinc in dilute sulphuric or hydrochloric acid, with
which antimonic oxide, bydrochlorate of antimonic oxide, tartar-
emetic, or antimanium diaphoreticurn is mixed. (Thomson, A. Vogel.)
The pure gas is completely decomposed and absorbed by an aqueous
solution of nitrate of silver; any free hydrogen that may be mixed with
it, remains unaltered. (Lassaigne.)
Praperties.'^ColouTleas ; has a peculiar odour; smella like arseniu-
retted hydrogen (Thomson); has a peculiar odour, but not like
garlic (Pfaff) ; has a nauseating odour, somewhat like that of hydrosul-
phuric acid, but does not affect lead-salts. (Lassaigne.) It is inodorous.
(Capitaine.)
Calculation. Lassaigne.
Sb 129 .... 9773 97-58
3H 3 .... 2-27 2-42
8bH» 132 .... 100-00 10000
Lassaigne decomposed the gas with nitrate of silver, and from the
proportion of the antimony to the silver in the resulting precipitate,
calculated the proportion of the antimony to the hydrogen in the gas.
DecompoiUions, — 1. At a temperature below redness, the gas is
resolved into antimony which is deposited in the form of a tin-white,
metallic fflobule, and nydrogen which escapes as gas. (Thomson.) — The
decomposition is affected even at a much lower temperature than that of
arseniuretted hydrogen. (Simon.) The decomposition is not attended
with perceptible diminution of volume. [?] (Lassaigne.) If the gas is
decomposed by passing it through a hot tube, and iodine is then allowed
to volatilize in the tube, the iodine forms with the metallic film a reddish-
yellow amorphous mass insoluble in water (whereas arsenic would pro-
duce a brilliant, straw-coloured, crystalline compound, soluble in water).
(Meissner k Hankel, J, pr. Chem. 25, 243; see also pp. 269, 270.) — 2. When
mixed with oxygen gas or atmospheric air, it explodes violently by the
electric spark. (Thomson.) — ^When antimoniuretted hydrogen contained
in a glass jar, is set on fire in contact with air, white nakes of antimonic
oxide are deposited, but no metallic antimony (a character which serves
to distinguish it from arseniuretted hydrogen). (A. Vogel, L. A. Buchner.)
If a stream of the gas passing through a fine opening in a glass tube be
894 ANTIMONT.
inflamed^ it burns with a pale blaLib-greeii ligbt^ prodneiiig dense wbite
clouds of antimonic oxide, which forms a crystalline sublimate. Glass
or porcelain if held in the flame, becomes covered with a metallic film
similar to that obtained with arseniuretted hydrogen. (Thomson.) The
film is black in the centre, and ^^y on the circumference ; but if the
tube is heated to redness at a distance of some inches from the exit of
the gas, the film acquires a bright metallic lustre. (Pfaff.) In general,
the antimony spots are darker than those of arsenic, and appear brown
only when the antimony is in very small quantity; when the gas contains
both antimony and arsenic, the metallic film appears black in the centre
from the more fixed antimony, and brown on the circumference from the
more volatile arsenic. An alloy of 5,000 parts of zinc to 1 part of anti-
mony, yields, when dissolyed in dilute sulphuric acid, a gas which gives
well marked spots; with 11,000 parts of zinc, a few distinct spots are
still obtained; and with 13,000 parts of zinc, (which is the limit,) only
faint spots. If 0*0156 of a grain of tartar-emetic be added to a mixture
of zinc and sulphuric acid, distinct spots of metal are deposited; with
0*01044 of a grain, less distinct, and with '00522 of a grain, (the limit,)
only two or three very small spots. (Brett, Phil, Mag, •/. 21, 405.) —
3. When antimoniuretted hydrogen is kept for several days, it deposits
antimony on the sides of the vessel, and in the water in which the
receiver stands. This is more especially the case with gas which has
been slowly disengaged; when rapidly evolved, it deposits thin flakes of
antimony, even on the neck of the bottle in which it Is generated.
(A. Vogel.) The water round the receiver becomes blackened by the
precipitated antimony. The larger the quantity of free hydrogen present
in the gas, the more slowly does this decomposition take place. (Pfafi*.)
The decomposition is greatly accelerated by exposure to the sun's rays;
it is not attended with perceptible change of volume. (Lassaigne.) This
decomposition is due either to a slow combustion, possibly caused by the
presence of a small quantity of air, or it is connected with the cause
first described, viz. rise of temperature.
4. Chlorine, at ordinary temperatures, acts but slowly on antimo-
niuretted-hydrogen, forming a small quantity of chloride of antimony
[and hydrochloric acid], but without any separation of metallic anti-
mony; this change takes place even when the quantity of chlorine is very
small. (A. Vogel, L. A. buchner.) The mixture explodes by the electric
spark. (Thomson.) On passing the gas through chlorine-water, nearly
all the antimony is absorbed, aqueous hydrochloric acid and white flakes
of oxy-chloride of antimony being formed. (Simon.) — 5. An aqueous
solution of bromine acts in a similar manner, retaining the whole of
the antimony, and depositing white flakes, but without losing its own
colour. (Simon.) — 6. Aqueous solution of iodine retains the ffreater part
of the antimony, becoming colourless, and depositing white flfluces, which,
if the stream of gas be continued, become flrst brown and then black,
and are converted into metallic antimony; the supernatant liquid does
not contain a trace of antimony. (Simon.)
7. The gas is slightly decomposed by an aqueous solution of sulphate
of copper, but only when passed through it for a long time ; a few black
flakes of antimonide of copper being deposited. (Simon.) — 8. An aqueous
solution of nitrate of silver precipitates the whole of the antimony, in
the form of a black powder of antimonide of silver. (Simon.) Probably
thus i—
8(JlgO, NOfi) + SbH« = Ag*Sb + 3N0» + 8H0.
PHOSPHIDE OF ANTIMONY. 386
Wlien the gas likewise contains arseninretted hydrogen, the arsenie
remains in the liquid as arsenious acid. (Simon.) — 9. When the gas is
slowly passed through an aqueous solution of protochloride of meroury,
the whole of the antimony is separated, and the liquid becomes turbid,
and deposits white flakes, which first turn grey and afterwards black.
(Simon.) The grey precipitate when heated, yields a sublimate of dichlo-
ride of mercury, and leaves a yellow fused mass of antimonious acid,
[antimonio oxide 1] When heated with nitric acid, it is converted into
dichloride of mercury, while the acid dissolves antimony. (Simon.)
Probably a mixture of dichloride of mercury and oxy-chloride of anti-
mony is first formed : —
12Hga + SbH' = 6Hg2Cl + SbCl« + 3HC1.
the SbCP thus produced, is resolved by the water into hydrochloric acid
and oxy-chloriae of antimony; — with a larger proportion of the gas,
whereby the precipitate is rendered darker, a mixture of dichloride of
mercury and metallic antimony is probably formed :
6HgCl + SbH8 = 3Hg2Cl + Sb + 3HC1 ;
and the black precipitate is probably Hg^Sb, thus :
3HgCl + SbH» = Hg»Sb + 3HCl.
—-10. The gas is decomposed by a solution of chloride of ^old. (Jacquelain,
Compt, rend, 16, 31.)— With an aqueous solution of bichloride of pla-
tinum, it rapidly forms a black precipitate of antimonide of platinum,
the whole of the antimony being separated. (Simon.)
.11. When passed through an alcoholic solution of potash or soda, it
imparts a brownish-yellow, and then a dark-brown colour to the liquid,
and, lastly, renders it turbid, and separates brownish-black flakes ; an
alcoholic solution of ammonia behaves similarly, but the turbidity is more
slowly produced. — Arseninretted hydrogen gas does not act on alcoholic
solutions of the alkalis ; but a gaseous mixture evolved from zinc, sul-
phuric acid, arsenious acid, and tartar-emetic, in which 10,000 parts of
arsenious acid are mixed with 1 part of emetic-tartar, still imparts a
brown colour to alcoholic solutions of the alkalis, and, with 100,000 parts
of arsenious acid to 1 of tartar-emetic, a yellow colour. (Meissner &
Hankel, J» pr. Gkem, 25, 243.^ — The following substances exert no
decomposing action on antimoniuretted hydrogen gajs; viz., strong sul-
phuric acid, hydrosulphuric acid, ammonia, potash, arsenious acid mixed
with water, acetate of lead, sulphate of zinc, and protochloride of iron.
(Simon.)
The gas is not sensibly absorbed by water. (Simon.)
Antimonic oxide does not combine with Varhwiie acid.
AkTIKOKT AMD PaOSPHORITS*
A. Phosphide op Antimony.— 1. Prepared by fusing antimony
with an equal weight of glacial phosphoric acid, and with or without
•yV of its weight of charcoal powder.— 2. By throwing pieces of phospho-
rus on fused antimony. Wnite, brittle substance, having the metallic
lustre and a laminated fracture; when thrown on red-hot charcoal,
it bums with a small greenish flame. (PeUetier.)— When prepared by
336
ANTIMONY.
the second method, it has a fine-grained fracture, appears somewhat blaer
than antimony itself, and when heated on charcoal before the blowpipe,
does not 'exhibit the green flame; contains 15-46 per cent, of phos-
phorus. (Landgrebe, Schw, 53, 4G9.)
B. Phosphite op Antimonic Oxide. — When terchloride of phos-
phorus, dissolved in water and neutralized with ammonia, is mixed
with tartar-emetic, and then with hydrochloric acid, a precipitate is
obtained, which is white— evolves hydrogen gas free from phosphorus,
on being ignited after dry ins — and is soluble in excess of hydrochloric
acid. (H. Rose, Fo^ff. f), 45.)
C. Phosphate of Antimonic Oxide. — Aqueous phosphoric acid
dissolves a small quantity of antimonic oxide; the solution does not
crystallize, but yields on evaporation, a blackish green mass, which fusee
in a strong fire, forming a transparent glass. (Wenzel.) — From the acid
solution, Brandes (Schw, 62, 201), obtained small prisms c, which, when
washed with cold water, left 5, and after several hours* washing with
boiling water, the salt a,
a. Brandes.
4SbO» 612-0 .... 89-55 89-40
PO* 71-4 .... 10-45 10-31
4SbO»,PO*
... 683-4
... 306-0
71-4
■ »>•
b.
• ••*
••••
100-00
81-08
18-92
99*71
2Sb05
PO»
Brandes.
80-40
19-55
2Sb(y»,PO* 377-4
28bO»
3PO*
2HO
€.
3060
214-2
18-0
10000
56-86
39-80
3-34
99-95
Brandes.
5600
40-65
4 00
2SbO«,3PO* + 2Aq. 638-2
10000
100-65
1 D. Pyrophosphate op Antimonic Oxide. — When antimonic oxide
is boiled with solution of pyrophosphate of soda, a liquid is obtained,
which holds a large quantity of the oxide in solution, and, when evapo-
rated oyer oil of vitriol, forms a cauliflower-like mass. On digesting this
mass with water, the greater part of the antimonic oxide is left undis-
solved. (Schwarzenberg, Ann, Fharm, 65, 2.) IT
Antimony and Sulphur.
The compound SbS' (the existence of which was suspected by
Faraday, Foff^. 23, 31 4), does not appear to exist. When an intimate
mixture of 1 atom of antimony and 2 atoms of tersulphide of antimony
is fused out of contact of air, and then slowly cooled, a quantity of the
metal separates, amounting to 63 per cent, of that which was added to
the sulphur compound. The superposed sulphide of antimony consists
of a mixture of tersulphide of antimony and metallic antimony in feathery
crystals; the latter remains behind on dissolving the tersulphide in
hydrochloric acid. From this it appears, that tersulphide of antimony is
capable of dissolving a small quantity of metallic antimony at its fusing
pdintj but deposits it again on cooling. (Berzelius, Foffff. 37, 163.)
TERSULPHIDE OF ANTIMONY. 337
A. Tersulphide op Antimony, Antimonious Sulphide, Sulph-
ANTiMONious AciD. — a. Crystallized, — Orey Sulphide of Antimony,
Spiessfflanz, roher Splessglam, Antimonium crudum. — Found native
in large quantity as Grey Antimony ore, which frequently also
contains arsenic, lead, iron, and copper. On the large scale it is sepa-
rated from the gangue by fusion. It is readily formed by fusing a
mixture of its elements, or by fusing one of the oxides of antimony
with excess of sulphur; the combination is attended with slight incan-
descence.
The presence of lead, iron, and copper is detected in sulphide of
antimony in the same manner as in the regulus. To discover sulphide of
arsenic, Liebig boils the finely powdered sulphide of antimony repeatedly
with strong hydrochloric acid, till no more hydrosulphuric acid is dis-
engaged; washes the residue, which contains the sulphide of arsenic, with
water holding tartaric acid in solution; mixes it with carbonate of soda;
and ignites it in a current of hydrogen gas, to sublime the arsenic (p. 274).
Since finely divided sulphide of antimony is likewise slightly soluble in
ammonia, we must not assume that sulphide of arsenic is present, merely
because, after a few days' digestion with ammonia, the resulting liquid
gives a yellowish-red precipitate with hydrochloric acid. In this case,
the ammoniacal solution should first be exposed to the air for a few days
till it ceases to become turbid from separation of antimonic oxide. After
this, hydrochloric acid precipitates any arsenic that may be present, in
the form of yellow sulphide of arsenic, which must then be more closely
examined. If nothing more than a white cloudiness is produced by the
hydrochloric acid, it arises merely from antimonic oxide still held in
solution by the ammonia. (Garot, N. J, Pkai'm. 3, 118; also J, pr. Chem.
29, 83.)
To free commercial sulphide of antimony from sulphide of arsenic,
it is digested in the levigated state with twice its weight of aqueous
ammonia in a covered vessel, for 48 hours, the whole being frequently
stirred ; after which the residue is washed. The ammonia removes the
sulphide of arsenic almost completely. (Weigand, CentralblaU, 1840, 175.)
To obtain pure tersulphide of antimony, a finely powdered mixture of 13
parts of purified antimony and 5 parts of flowers of sulphur is projected
by successive portions into a red-hot crucible, heated till it is per*
fectly fused, and then left to cool. When the antimony is not finely
pulverized, part of it does not combine with the sulphur, but is deposited
in the metallic state below the sulphide of antimony. (Liebig.)
Crystalline system of the native compound, the right prismatic:
Figf» 44 (sometimes with the ^face), 70, and other forms, a '. d ^=i
107° 56'; a! : a behind = HO'' 58'; a \ oT — 109^ 24'; a : tt =
144^ 42'; tt : y = 87° 54' (Hauy), 88° 40' (Phillios), 89° 15' (Mohs).
Cleavage distinct parallel to t, less distinct parallel to p^ m, and u.
Artificially prepared sulphide of antimony has a radiated structure.
Sp. gr. 4*620 (Mohs), 4- 626 (Breithaupt); the tersulphide precipitated
from the hydrochloric acid solution by hydrosulphuric acid, and then
fused, has a specific gravity of 4*752. (Karsten.) Of the same degree
of hardness as rock-salt ; very brittle. Colour lead-grey j yields a
blackish-grey powder. Easily fusible; on solidifying after fusion, it
contracts strongly and becomes interspersed with cracks. At a strong
red-heat, it boils and may be distilled without decomposition if the
air be excluded.
VOL. IT, z
338 ANTIMONY.
CalcnUtioii. BeRelias. ThonMon. Bergman.
Sb « 129 .... 72-88 72-8 .... 73'77 .... 74
3S 48 .... 27-12 27-2 .... 2623 .... 26
SbS» 177 .... 10000 ~. 1000 .... 100*00 .... 100
J. Dayy. YanqueUn. Proust.
Sb 74-16 .... 75 .... 76-1
3S 25-84 .... 25 .... 24'9
SbS» .... 100-00 .... 100 .... 100-0
DecompasUions,''^!, When heated in the air not qnite to its fusing
point it consumes away^ and at a higher temperature hams with a hlae
name, yielding in hoth cases sulphnrons acid gas and antimonious acid.
The antimonious acid is mixed at first with antimonic oxide. According
to Buchner {Eepert. 13, 202^, the powder is oxidized slowly in the air at
ordinary temperatures, so that, after a while, cream of tartar dissolres
out antimonic oxide from it. The grey antimony ore sometimes appears
to be converted into the white variety. (Haidmger, Po(7^. 11, 178.)—
2. Hot nitric acid decomposes sulphide of antimony, yielding sulphur,
sulphuric acid, and antimonic oxide, which remains in the form of a white
powder mixed with the sulphur, in comhination partly with sulphuric
and partly with nitric acid. In a similar manner, dilute sulphuric acid
mixed with nitre gradually produces, with the aid of heat, a mixture of
sulphur and sulphate of antimonic oxide; and a mixture of hydrochloric
acid with a moderate quantity of nitric acid forms a solution of terchloride
of antimony, and separates sulphur. — 3. Oil of vitriol hoiled with
tersulphide of antimony slowly produces a solution of acid sulphate of
antimonic oxide, sulphurous acid being disengaged, and a fused mass of
sulphur separated: the solution is decomposed by water. — 4. When
aqueous vapour is passed over ignited sulphide of antimony, a large
quantity of hydrosulphuric acid and antimonic oxide is formed, the latter
subliming in combination with nndecomposed sulphide of antimony, in the
form of an orange-yellow substance. (Regnanlt, Ann. Chim. Pkys, 62,
383.) — 5. Hydrochloric acid gas decomposes heated sulphide of anti-
mony, yielding hydrosulphuric acid gas and terchloride of antimony
(SbS» + 3HCl=SbCl» + 3HS); whereas, hot concentrated hydrochloric acid
produces acid hydrochlorate of antimonic oxide, with eyolution of hydro-
sulphuric acid gas. — 6. Chlorine gas converts heated sulphide of antimony
into chloride of sulphur and terchloride of antimony. (H. Rose.) —
7. When hydrogen gas is passed over ignited sulphide of antimony,
hydrosulphuric acid is formed and antimony reduced. (H. Rose, Pogg.
3, 443; Berthier.) Phosphuretted hydrogen gas in contact with ignited
sulphide of antimony yields hydrosulphuric acid gas together with
phosphorus and metallic antimony, which sublime. (H. Rose, Pogg. 20,
836.) — 8. Charcoal decomposes tersulphide of antimony at a strong
red heat, the products being bisulphide of carbon and metallic antimony.
(Berthier, Ann, Chim, Phys. 22, 239.) By passing carbonic oxide gas
over hot sulphide of antimony, the metal is imperfectly reduced. (Gobel,
J, pr. Chem. 6, 388.) — 9. Many metals, e. g. potassium, sodium, tin, iron,
copper, &c. likewise separate the sulphur at a red heat; the reduced
antimony combines with the excess of the other metal, and the new
metallic sulphide sometimes unites with the undecomposed portion of
sulphide of antimony. Metallic oxides mixed with charcoal act in a
similar manner to the metals themselves, because the charcoal separates
their oxygen. — 10. A mixture of tersulphide of antimony and cyanide of
i
TERSULPHIDB OP ANTIMONY. 339
potaesinm yields, at the fusing point, metallic aatimonj and snlpboojanide
of potassium. (Liebig.) — 11. When mixed with nitre, sulphide of antimony
explodes at a red heat, yielding nitrate and antimoniate of potash.
12. When the fixed alkalis are ignited with tersulphide of antimony,
they are decomposed, together with a portion of the tersnlphide, forming
antimonio oxide and a sulphide of the alkali-metal, by interchange of the
oxygen and sulphur; the alkaline sulphide then combines with the
sulphide of antimony, which remains undecomposed, producing a double
sulphide of antimony and the alkali-metal; and the antimonic oxide
formed combines either with undecomposed alkali when that substance
is in excess, or with a portion of the tersulphide of antimony, when an
excess of that compound has been used. (Bersselius.) — a. When carbonate
of potash is ignited with excess of tersulphide of antimony (the carbonic
acid, since it escapes, may be neglected), the whole of the potash and a
portion of the sulphide of antimony are decomposed, yielding sulphide of
potassium and antimonic oxide. Each of these compounds then takes up
as large a portion of the excess of sulphide of antimony as it is capable of
combining with, so that two layers are formed, the lower one of which
contains the antimonio oxide combined with the sulphide of antimony,
and the upper the sulphide of potassium combined with the same substance.
(Sch. 60.)
3KO + SbS8 + xSbS» + ySbS» = 3KS, xSbS» + SbO»,ySbS*.
—6. When« on the contrary, tersulphide of antimony is ignited with
excess of carbonate of potash, 5 atoms of the sulphide do not expel more
than 7 atoms of carbonic acid ; and the rest of the carbonate of potash
remains unaltered. The following reactions then take place: 6 atoms of
potash and 2 atoms of tersulphide of antimony proauce 6 atoms of
sulphide of potassium and 2 atoms of antimonic oxide; the sotenth atom
of potash unites with the 2 atoms of antimonic oxide, and the 6 atoms of
sulphide of potassium with 3 atoms of tersnlphide of antimony. (/SoA. 61.)
7KO -I- 5SbS» » 6KS, SSbSP + KG, 26bO«.
(Berzelius.) By strongly igniting this mass in a close ressel, a small
quantity of metallic antimony is reduced, because, according to Berzelius,
the compound of antimonic oxide and potash is resolved into antimony
and antimonite of potash: 2(KO,2SbO') = 2KO,3SbO*+ Sb ; but
according to H. Rose, because the compound of sulphide of potassium
and tersulphide of antimony is converted into a compound of sul-
phide of potassium with pentasulphide of antimony, — somewhat in
the followmff manner : lOKS + 5SbS* = lOKS + 3SbS» + 2Sb.— Bv
boiling tersulphide of antimony with aqueous potash, a solution Is
obtained which contains sulphide of potassium in combination with
tersulphide of antimony, and a small quantity of the compound of anti-
monic oxide and potash, while a yellowish-brown mixture of the latter
compound and oxy-sulphide of antimony {Crocu$ antimanit) is left behind.
The reaction is the same in this case as in the dry way, if we assume that
the metallic sulphides dissolve in water without change of composition :
dKO + SbS' yield 3KS and SbO'; the SKS then dissolves a Quantity of
the undecomposed SbS', increasing with the temperature of the liquid ;
and the SbO' produced combines partly with potash, forming a compound
which remains for the most part undissolved, and partly with the excess
of sulphide of antimony. If, however, we suppose that the metallic
sulphides dissolve as hydros ulphates of the metallic oxides, then the
reaction will be as follows: 3KO-hSbS* + 3HO = 3(KO,HS) + SbO»;
z2
340 ANTIMONT.
the 3(K0,HS) tben disBoWe » portion of the remaining SbS', which,
hy undergoing mutnal docomposition with 3 atoms of water, is con-
verted into SbO',3HS, so that a. donbte bydroaulphate is produced
=(KO,HS)+i(SbO',3HS). The other changes are explained a« in the
first scheme. Boiling carbonate of potash or soda act^ on snlphide of
adtimony in a similar manner, but much less strongly. Orey eolphide of
antimony is but very sparingly soluble in aqueons ammoniiv. If one part
"' " ' iwdered sulphide of antimony is left in contact with 1000 parts
i for some days, abont half of it disaolvee; the other portion
remaining uudiasolved even when treated with fresh ammonia. The
yellow solution gives a red precipitate with hydrochloric acid. (Qarot.)
b. Amorp/umi Termlpkidt of Antimony. — Browniih red Sulphide of Anti-
taovf. Mineral Kermea, Cartbiuiui powder, Kennei Minenle, Fulrii CirtliaBiuionun.
— [The liermes which Becquerel obtained, apparently in octohedrons, by
electrolysis {I. 394^ deserves more precise examination.] — Formatum and
Preparation. — 1. This anbstance is obtained by fusing grey sulphide of
antimony in a thin rlass vessel for a long time till it forms a perfectly
nnifonn mass, and then throwing the whole as qnickly as possible info
cold water. (Fuchs, Fogg. 31, 578.) The shorter the time of fusion, and
the slower the cooling, the larger is the quantity of crystallized sulphide of
antimony mixed with the kermea.
2. Antimouic oxide is precipitated from its solutions in acids by
bydrosalphoric acid. — a. By ptiesing hydrosnlphnrio acid gas throngh the
aqueous solution of tartar-emetio, as long as a precipitate is formed, and
afterwards washing the precipitate contiQDOiuly witli hot water. — Since
the precipitated hemes is mixed with cream of tartar, which is difficultly
soluble, Schmidt {Mag, Phartn. 13, 56) decants the solution from the pre-
cipitate, adds water to the latter and enough carbonate of potash to render
the liquid slightly alkaline — whereby the cream of tartar is converted
into the easily soluble monotartrate of potash — and lastly washes the
kermes on a filter. — h. By precipitating the clear solution of terchloride of
antimony in aqueous tartaric acid with hydrosnlpbnric acid. At first,
a reddish yellow compound of sulphide of antimony with a email quantity
of the terchloride is precipitated; so that it is necessary to saturate the
liquid completely with hydros ulph uric acid, and then to heat the mixture
very gently for some time; after this, the kermes contuns but a trace
of terchloride of antimony. (H. Rose,)
3. Finely pounded grey sulphide of antimony is boiled for a lontr time
with an aqueous eotutiun of carbonate of potash or soda, the liquid filtered
at a boiline heat, and then left to dejiosit the kermes on cooling. The
alkaline solution filtered from the precipitated kermes, if boiled with the
insoluble residue and fiitored hot, again deposits kermes, and so on,
several times. — This is the oldest method of preparing kermes, as practised
by Qlauber, Simon, and La Ligerie. — When the grey sulphide of antimony
' ' )i]ed with a strong solution of carbonate of potash, carbonic acid is
ved; but with a <Utute solution this is not the case (Dufios); neither is
onio acid evolved when carbonate of soda is used, — an alkaline sesqui-
onate being probably formed. (Duflos, 0. Henry, H. Hose.) — While the
ter part of the alkaline carbonate remains unchanged, or becomes
ged with more carbonic acid, a small portion of the alkali acts upon
tulphide of antimony, in such a manner as to produce antimonic oxide
a sulphide of the alkali-metal. The latter dissolves part of the
dning sulphide of antimony, the greater part of which separates in
MINERAL KERMSS. 341
the form of kermes on cooling. The antimonic oxide is contained in the
liquid in combination with the alkali^ but partly separates on cooling,
combined with a small quantity of alkali and mixed with the kermes, in
the form of acuminated six-sided needles, which may be detected by the
microscope. Since, however, it does not separate so rapidly as the
kermes, the latter may be obtained free from antimonic oxide, by collecting
it on a filter immediately after its formation. Carbonate of potash pre-
cipitates a smaller quantity of antimonic oxide than carbonate of soda.
The larger the excess of alkaline carbonate present, the smaller is the
proportion of antimonic oxide thrown down. Thus, by boiling 1 part of
grey sulphide of antimony with 1 part of crystallized carbonate of soda,
only a small quantity of antimonic oxide is precipitated, and with still
more carbonato of soda (which, however, gives but a scanty precipitate of
kermes), the whole of the antimonic oxide remains dissolved, provided
the kermes be rapidly collected on a filter. (H. Rose.) The solution
filtered from the kermes contains — ^besides a large quantity of alkaline
carbonate — more or less sulphide of potassium or sodium, still combined
with a small proportion of sulphide of antimony, and accordingly, when
treated with the stronger acids, it evolves carbonic acid and hydrosulphuric
acid gas, and deposits a yellowish-red precipitate. (0. Henry, Liobig.)
According to H. Rose, it does not give off hydrosulphuric acid gas,
because it likewise contains antimonic oxide, in quantity more than suffi-
cient to form sulphide of antimony with the hydrosulphuric acid separated
from the sulphide of sodium. When grey sulphide of antimony is
boiled with a (Glute solution of carbonate of potash (which likewise does
not evolve any carbonic acid gas), the solution filtered from the kermes
does not give off hydrosulphuric acid on the addition of the stronger acids.
(Dnflos.) — The yellowish red precipitate produced by acids is kermes
mixed, after a while, with pentasnlphide of antimony: the longer the
solution had previously been exposed to the air, the sooner does the pre-
cipitation of pentasnlphide take place.
The residue obtained after eidiausting grey sulphide of antimony with
the boiling solution of an alkaline carbonate, consists of sulphide of anti-
mony, antimonic oxide, and free alkali. (Duflos.)
When grey sulphide of antimony is boiled, for 10 minutes only, with
carbonate of soda in a close vessel furnished with a gas-delivery tube, the
filtrate yields a flocculent, greyish-brown kermes, which, when digested
with a hot solution of tartaric acid, deepens in colour, and gives up a
large quantity of antimonic oxide and soda — ^the latter being contained in
the kermes in the form of sulphide of antimony and sodium; the superna-
tant mother-liquid contains sulphide of sodium. If, on the contrary, the
mixture be boiled for an hour in an open vessel, a bright-coloured, pulveru-
lent kermes is obtained, which gives up to acids a large quantity of anti-
monic oxide, and very little soda, and when decomposed by hydrogen gas
yields 7 1*3. ...73*8 per cent, of antimony, with a small proportion of sul-
phide of sodium. (Liebig.^
The kermes 2, 6, precipitated by hydrosulphuric acid, is not soluble in
a cold solution of carbonate of soda; but in a hot solution, it dissolves much
more abundantly than the grey sulphide of antimony, and evolves car-
bonic acid gas. The kermes which separates from the filtrate on cooling
contains antimonic oxide, and the supernatant liquid contains sulphide of
sodium. (Liebig.) In this case, a much larger quantity of antimonic
oxide is aeposited with the kermes. than when the grey sulphide of anti-
mony is used, because the solution contains a much smaller excess of car-
1
342 AKTIMONT.
bonate of soda. (H. Rosa.) When the boiling is continued for 10 minntea
only, the resulting dingy ooloared kermes behares in a similar manner to
that which is prepared from the grey sulphide by the same process, and
the supernatant liquid holds in solution but a small quantity of antimouio
oxide and sulphide of sodium. But if the boiling be continued for an
hour, a more orilliant and finely diyided kermes is precipitated, having
the same properties as the kermes obtained by boiUng grey sulphide of
antimony for an hour, and the supernatant mother-liquid contains more
sulphide of sodiunii together with a small quantity of pentasulphide of
antimony, produced by the action of the air during the prolongea ebulli-
tion. ^Liebig.)
With 100 parts of grey sulphide of antimony, the following propor-
tions of diy carbonate of potash and of water ha^e been used; 25 parts of
carbonate of potash to 200 parts of water. {Fari$ Codex, 1748.)— 222 : 1788;
yields after boiling for a quarter of an hour, 18 parts of kermes free from
oxide, the mother-liquid containing but a trace of sulphide of antimony;
but after two hours* boiling the yield is only 13 parts of kermes free from
oxide, and the mother-liquid contains more sulphide of antimony. (Duflos.)
— -400 : 1600; an old recipe of La Ligerie. — 1600 : 4800; yield^ after a
quarter of an honr^s boiling, 20 parts of pure kermes. (Duflos.) — By boil-
ing 100 parts of sulphide of antimony with 200 parts of carbonate of
potash and 1800 parts of water for two hours, and then precipitating the
filtrate immediately with hydrochloric acid, 28 parts of kermes iree from
oxide are obtained. (Duflos.)
Clusel boils 1 part of grey sulphide of antimony with 20 parts of crys-
tallised carbonate of soda and 200 parts of water. The resulting kermes
contains, according to Oay-Lussac, 30 per cent, of antimouio oxide. When
the mixture is boiled for half an hour, it contains 18 per cent, of oxide;,
but in reality, the portions of kermes first precipitated contain only 14
per cent of oxide, while the subsequent portions are contaminated with
nearly 29 per cent. (Duflos.) — A mixture of 100 parts of sulphide of anti-
mony with 800 parts of crystallised carbonate of soda and 2400 parts of
water boiled for half an hour, deposits 8 parts of kermes containing
more than 1 part of antimouio oxide; by again boiling the mother-liquid
with the residue, 9 parts of kermes are obtained, contaminated with 1 *5
parts of oxide. /Duflos.)
Carbonate or potash produces a larger quantity of kermes than car-
bonate of soda (0. Henry) ; but the kermes prepared with carbonate of
soda has a finer red colour. (Clusel.)
As the grey sulphide of antimony is diffioultiy soluble in carbonate of
8oda» the precipitated red sulphide is preferable for this process. One
part of finely powdered grey sulphide should therefore be boiled with
1 part of hydrate of potash and 30 parts of water for one hour; the filtrate
precipitated while still hot by dilute sulphuric acid; and the mixed salts di-
yidea into three equal parts, each of which is then to be washed with water
in a separate vessel, by subsidence and decantation, and afterwards collected
on a filter. The precipitate collected on the first filter is then thrown by
successive portions into a boiling filtered solution of 1 part of dry car-
bonate of soda in 34 parts of water, and the whole boiled for an hour;
and the solution — which need not be filtered, since nothing remains undis-
solved — is then slowly cooled to separate the kermes. The solution
poured ofi* from the precipitated kermes is atfain raised to the boiling
point, and the contents of the second filter added to it^ and similarly with
the third filter. The kermes deposited after the second boiling has usually
MINERAL K6BMES. 343
the finest eolour. The kemea thus pr^Mkred amoants, after waflhing with
oold water and drying, to half the qnantity of the grey sulphide used.
It must be regarded as 8b0^2SbS^ (a composition similar to that of red
antimony ore), but it still contains between 3 and 1^ per cent, of soda.
(Liebig, ffandworterb, 1, 427.)
4. Grey sulphide of antimony is boiled with solution of potash, not in
excess, and the liquid filtered hot and then left to cooL The solution
filtered from the precipitated kermes, if boiled afresh with the undissolYed
residue, yields a small additional quantity of kermes. ' Caustic potash
dissolves sulphide of antimony much more abundantly than the carbonate;
in other respects, the process is mainly the same. Thus dKO is resolved
with SbS' into dKS and SbO*; the 3KS then dissolves a certain quantity
of the remaining SbS', a portion of which separates on cooling in the
form of kermes. The SbO' thus formed remains partly dissolved in the
alkaline solutiou, and partly, together with potash, combines with the
SbS' which remains undissolyed, thereby converting it into a yellow or
brown crocus, from which, after a while, the liquid filtered from the
kermes is unable to abstract any more SbS'. According to Rose, however,
the kermes thus obtained differs from that prepared with alkaline
carbonates. It is not precipitated in the state of powder, but forms a
dark brown jelly on oooline; it is difficult to wash and dry, and in drying
shrinks up to a hard dark-brown mass having a conchoiaal fracture. It
does not contain antimonic oxide, but is in reality a feeble compound
of teraulphide of antimony with a small quantity of sulphantimoniate
of potassium. After washing for a short time, its composition is
2SbS'>4*K8,SbS^ after longer washing with hot water, 9SbS'+KS,SbS«.
The formation of the KS,8bS' is to be attributed either to the partial
resolution of the SbS' by boiling into metallic antimony and SbS', or — as
Bose considers more probable-— to the action of the ab, whereby a portion
of the antimony is oxidized and the proportion of the sulphur to the
antimony increased. Hence kermes of this kind does not yield antimonic
oxide when digested with a boiling solution of cream of tartar, but merely
gives off a small quantity of hydrosulphuric acid gas; with dilute hydro-
chloric acid it evolves hydrosulphuric acid gas in abundance; and on
iffnition in a current of hydrogen, it yields water (previously contained in
the KS,SbS^ as water of crystallisation) and metallic antimony, sur-
rounded however by fused K8,SbS^ (H. Rose.)
When grey sulphide of antimony is boiled with excess of potash, the
filtrate does not deposit kermes on cooUng. (Duflos, H. Rose.^ Bat if
carbonic acid gas be passed through the solution, a brilliant Kermes is
precipitated in large quantity; and when the carbonic acid ceases to
cause any further precipitation, the stronger acids, after expelling the
carbonic acid, throw down pentasulphide of antimony from the liquid
filtered from the kermes. Moreover, if the liquid precipitated by car-
bonic acid and filtered from the kermes be boiled with a fresh quantity
of sulphide of antimony, it deposits kermes on cooling, because the
solution then contains carbonate of potash; on again passing carbonic
acid through the liquid, no further precipitate is formed. (Rennsman,
Tasehenb. 1822, 184.) [The carbonic acid precipitates not only the
tersnlphide but also the pentasulphide of antimony.] The above solution,
if treated with bicarbonate of potash or soda, instead of carbonic acid,
likewise deposits a large quantity of kermes which is free from antimonic
oxide, but on being treated with dilute hydrochloric aeid, deepen^ in
344 ANTIMONY.
oolonr and gives up a small portion of potash; when red need by hydrogen
gas, it leares antimony together with a double sulphide of antimony and
potassium. (Liebig.)
If 100 parts of grey sulphide of antimony are boiled for a quarter
of an hour with 30 pts. of hydrate of potash and 300 pts. of water,
the filtrate deposits, on cooling, 25 pts. of kermes free horn antimonic
oxide; by boiling the residue a second time with the mother-liquid,
10 pts. of kermes are obtained; a third boiling yields 3*2 pts. The
insoluble residue amounts to 49 pts. By boiling, for a quarter of an hour,
a mixture of 100 parts of sulphide of antimony, 33 pts. of hydrate of
potash, and 700 pts. of water, 13 pts. of kermes free from oxide are
obtained; and by the second boiling, 10 pts.; after this, nothing more is
deposited. The mother-liquid yields, on the addition of sulphuric acid,
18 pts. of brick-red kermes, containing but little pentasulphide of antimony,
since it dissolves entirely in strong hydrochloric acid, with the exception of
a small quantity of sulphur. A mixture of 100 pts. of sulphide of antimony
and 60 pts. of hydrate of potash yields, after boiling with water a quarter
of an hour, a filtrate which does not deposit any kermes on cooling. But
by boiling 100 pts. of sulphide of antimony and 100 pts. of hydrate of
potash with 2770 pts. of water for an hour and then filtering, a solution
is obtained which deposits 9 parts of yellowish kermes containing a large
quantity of antimonic oxide. The mother-liquid, if boiled three times
with the residue, deposits a yellow powder — amounting to 6*3, 5 '3, and 4 pts.
—which becomes richer in oxide after each boiling, so that the powder
obtained by a fourth boiling contains more than half its weight of antimonic
oxide. When the mother-liquid from the kermes has been boiled with
the insoluble residue till it no longer deposits kermes, it may again be
made to yield that substance in abundance and free from impurity, by
boiling it with fresh sulphide of antimony; and this process may be
repeated several times. (Duflos.)
According to some formulse, the potash-solution is boiled with sulphide
of antimony and free sulphur. For instance : a mixture of 100 pts. of
grey sulphide of antimony, 25 pts. of sulphur, 150 pts. of hydrate of
Sotash, and 2400 pts. of water, boiled for half an hour and then filtered,
eposits, on cooling, 33 pts. of fine brownish-red kermes free from
antimonic oxide or excess of sulphur; and by boiling the mother-liquid a
second time with the residue, the latter is entirely dissolved, and the
solution yields, on cooling, a kermes nearly as pure and abundant as in
the first case. The mother-liquid contains, not antimonic oxide, but
hyposulphite of potash. With 100 pts. of sulphide of antimony, 50 pts.
of sulphur, 150 pts. of hydrate of potash, and 4800 pts. of water, a
mixture of kermes and sulphur is deposited; and with 100 pts. of sulphide
of antimony, 100 pts. oi sulphur, 300 pts. of hydrate of potash, and
4800 pts. of water, the filtrate deposits nothing on cooling, and only
pentasulphide of antimony on the addition of acids. (Duflos.)
Kermes may also be prepared by the displacement method. Thus :
coarsely pounded glass or quartz is placed at the bottom of a funnel,
and upon it an intimate mixture of 1 pt. of very finely pulverized grey
sulphide of antimony and 2 pts. of dry carbonate of soda (carbonate of
potash, according to Boullay, produces a less brilliant kermes), 3 pts. of
slaked lime, and 4 pts. of washed and dry sand ; the mixture is covered
with a layer of sand ; and cold water allowed slowly to trickle upon it, as
long as the liquid which passes through is precipitated by acids. The
MINERAL KERMES. 345
kermes is thrown down from the filtrate by a current of carbonic acid gas
or bj bicarbonate of soda. (Musculus, J. Fharm, 22^ 241; also Ann,
Fharm. 18, 344.)
According to Liebig, kermes free from antimonio oxide may be most
conTeniently prepared by the following process : a mixture of 1 pt. of
finely pounded sulphide of antimony with 1 pt. of carbonate of potash,
1^ pt. of hydrate of potash, and 15 pts. of water is digested in a close
vessel for two hours; the filtrate diluted with a large quantity of water,
and precipitated by sulphuric acid; the precipitate boiled with dilute
sulphuric acid — to decompose the sulphide of potassium mixed with the
sulphide of antimony — and the residue washed with water.
5. Grey sulphide of antimony is fused with carbonate of potash or
soda, and the mass, consisting of a mixture of sulphantimonite of potassium
or sodium and the compound of antimonio oxide and potash or soda, is
exhausted with water, filtered hot, and the solution left to cool. If
37*5 pts. Tup wards of 7 At.) of carbonate of potash are used with 100 pts.
(8 At.) 01 sulphide of antimony, the following decomposition takes place:
88bS» + 7(K0, C02) = 6(KS, SbS^) + KO, 2Sb03 + 7C0«.
The compound of antimonio oxide and potash is resolved by strong
ignition into metallic antimony and antimonite of potash. Hot water
dissolves out the sulphide of potassium, together with the greater part of
the sulphide of antimony, which partially separates in the form of kermes
as the filtrate cools; the insoluble residue contains sulphide of antimony,
antimonio oxide, antimonious acid, and potash. (Berzelius.) The sepa-
ration of metallic antimony after prolonged fusion is due to the formation,
not of antimonite of potash, but of irS,SbS^ n)uflos, H. Rose.) This
decomposition is caused by the predisposing affinity of the sulphide of
sodium for pentasulphide of antimony, because the pentasulphide is a
stronffer acid than the tersulphide. When the fused mass is thoroughly
boiled with water, the double sulphide of antimony and potassium (or
sodium) dissolves in the water; and moreover, antimonio oxide is dissolved
by the undecomposed alkaline carbonate, and, on cooling, separates,
together with the kermes, in fine needles, which are free or almost free
from alkali. The quantity of kermes thus obtained is much greater than
that which is produced by boiling grey sulphide of antimony with
carbonate of soda, because more sulphide of antimony is decomposed by
fusion; but the kermes has more of a yellowish-brown colour, and
contains a larger quantity of antimonio oxide, though in variable propor-
tions. The more rapimy the kermes is collected on the filter after
cooling, the less is the quantity of oxide mixed with it. Besides
antimonio oxide, it contains a compound of sulphide of potassium or
sulphide of sodium with pentasulphide of antimony; hence a kermes
prepared in this manner with carbonate of soda yields, when decomposed
by chlorine gas, B'5 per cent, of chloride of sodium. The liquid Trom
which the kermes has been deposited on cooling in close vessels, contains
carbonate of soda, sulphantimonite of sodium, and sulphantimoniate of
sodium; so that on evaporation it yields, first crystals of sulphantimoniate
of sodium and then of carbonate of soda; and, on the addition of bicarbonate
of soda, deposits brownish-red kermes, in consequence of the decomposition
of the sulphantimonite of sodium. (H. Rose.)
The larger the proportion of alkaline carbonate, and the longer the
fusion is continued, the smaller is the quantity of antimonio oxide mixed
with the kermes; but if too much alkaline carbonate is used, no kermes is
346 AHTIMONT^
deporited. (Doflos.) When a mixture of 100 pis, of grey salpLide of
antimony with 37*5 pts. of carbonate of potash is heated merely to
tranquil fusion, no metallic antimony is separated, but the resulting mass,
after repeated exhaustion with water, yielda 21 ptia. of kermes, containing
25 per cent, of antimonic oxide. The aame mixture if kept at a red heat
for half an hour, deposits metallic antimony, and yields 19 pts. of kermes
containing 9 jj^r cent, of oxide. (Dufloa.) Geiger obtained a good
kermes, containing not more than 4 per cent, of oxide by the following
process recommended by Berzelius: — 100 pta. of sulphide of antimony
heated to tranquil fusion with 50 pts. of carbonate of soda yield, on the
first exhaustion with water, 17 pts. of kermes, containing 30 per cent, of
antimonic oxide; on the secono, 12*5 pts.; and on the third, 11 pts.
The mother liauid contains antimonic oxide. (With these proportions,
Pagenstecher obtained, by one exhaustion, 14 pts. of kermes containing 33
Eer cent, of oxide.) The same mixture kept at a red heat for half an
our, whereby a large quantity of metallic antimony is reduced, yields, in
three exhaustions, 28, 19, and 17 pts. (together = 64 pts.) of kermes
containing 9 per cent, of antimonic oxide. The mother-liquid contains
antimoniouB acid. 100 pts. of sulphide of antimony fused for a short
time with 67 pts. of carbonate of potash, yield, in one exhaustion with
water, 10*3 pts. of kermes containing 21 per cent, of antimonio oxide;
but after fusion for half an hour, whereby 8 pts. of metal are reduced, the
same mixture yields 23 pts. of kermes containing 6'5 per cent of oxide.
When a mixture of 100 parts of sulphide of antimony and 150 pis. of
carbonate of potash is fused for half an hour, 12*5 parts of metallie
antimony are separated; but the solution, after exhausting with water,
does not deposit any kermes on cooling; it contains antimonious acid, and,
when treated with acids, deposits a mixture of kermes and pentasulphide
of antimony. (Duflos.)
A mixture of ] 00 pts. of grey sulphide of antimony with 50 pts. of
dry carbonate of soda, yields 9 pts. of kermes containing 42 per cent.
of oxide; 100 sulphide of antimony and 100 carbonate of soda^ yield
52 pts. of kermes containing 34 per cent, of oxide. (Pagenstecher.)
1 00 pts. of sulphide of antimony 3rield with 50 pts. of dry caroonate
of soda a large quantity of kermes, rich in oxide, and resembliuff that
obtained with carbonate of soda in the wet way. The mother-liquid
gives with carbonate of ammonia a flame- coloured precipitate, and with
bicarbonate of soda, a brownish-red bulky precipitate ; both these preei*
pitates are free from antimonic oxide, and diasolye perfectly in a hot solu-
tion of carbonate of soda: the solution deposits good kermes on cooling. —
A mixture of 1 00 pts. o/ sulphide of antimony and 100 pts. of carbonate
of soda fuses less readily, yields more metaulio globules, and learea a
smaller residue when exhausted with water; nevertheless, the filtrate
deposits a smaller quantity of kermes on cooling, and, therefore, gives a
larg(!r precipitate with alkaline bicarbonates. — With 100 pts. of sulphide
of antimony to 200 pts. of carbonate of soda, a large quantity of metal is
reduced, and the mass dissolves almost completely in hot water; neverthe-
less the filtrate, when cooled in close vessels, does not deposit any kermea,
but, after a while, white crystalline flakes of antimonite of soda separate
from it; bicarbonate of soda, however, throws down from the filtrate a
considerable quantity of kermes free from antimonic oxide. Hence by
using an excess of carbonate of soda, too large a quantity of sulphide of
sodium is produced, whereby the whole of the sulphide of antimony ia
>*<)tained in solution. (Liebig,)
MIIQiUUi KEEMES. 347
Liebig fusee a xnixtare of 100 pts. snlphide of antimony and
25 pts. dry carbonate of soda at a gentle heat^ stirring all the while
with a pipe-stem ; then pours the mass out upon a brick; reduces it to
fine powder ; boils I pt. of the powder '\sith 2 pts. of crystallized carbo-
nate of soda and 16 pts. of water^ for an hour; filters; sets the liquid
aside to cool; decants the solution from the kermes; boils it with the
undissolyed residue; and so on repeatedly, till only yellow or yellowish-
brown Crocus a/niimonii remains. A single exhaustion yields but little
kermes ; but by repeating the boiling several timesj a large quantity of
very fine kermes is obtained.
In some cases, a small quantity of sulphur is added to the fused
mixture of sulphide of antimony and alkaline carbonate ; e, g» according
to DoUfuss, 100 pts. of sulphide of antimony, 4*7 parts of sulphur and 50
pts. of dry carbonate of soda; according to Trommsdorf, 100 : 6 : 50;
according to the Fharmac. Boruss. ed, 5, 100 : 50 : 75 ; and according to
Bucholz, 100 pts. of sulphide of antimony, 22 pis. of sulphur, and 150
pts. of carbonate of potash. These mixtures yield kermes- in larger
quantity and less contaminated with antimonic oxide, but of a dingy
colour, probably because it contains more sulphantimoniate of sodium
(or potassium). A mixture of 100 pts. of sulphide of antimony with
22 pts. of sulphur and 150 pts. of carbonate of potash, yields 63 pts. of
dingy kermes, containing 29 per cent, of oxide. (Pagenstecher.) The
fused mass dissolyes in boiling water, with the exception of 1 1 pts. and
yields 50 pts. of kermes containing 13*5 per cent, of oxide. With
100 pis, of sulphide of antimony, 25 pts. of sulphur, and 100 pts. of
carbonate of potash, 45 pts. of kermes are obtained, contaminated with
9 per cent, of antimonic oxide. (Duflos.)
6. Grey sulphide of antimony is ignited with a mixture of charcoal
and carbonate or sulphate of potash or soda, the resulting mass boiled
with water, and the filtrate set aside to cool. — ^As the liquid cools, a
gelatinous brown kermes separates, which consists of a compound of ter-
sulphide of antimony with sulphide of potassium or sodium, and is totally
different from officinal kermes. (Liebig.)
By fusing 100 pts. of sulpldde of antimony with 100 pts. of black
flux, exhausting the mass with water, and filtering hot, a solution is
obtained, which solidifies on cooling to a brown jelly; this substance
oolours the water yellow, even after long-continued washing, and is very
difficult to dry. But if carbonate of potash or soda is added to the hot
filtrate before it gelatinizes, and the whole boiled for half an hour, offi-
cinal kermes is precipitated on cooling, in the form of a brilliant, finely
divided powder, which is easily purified with water and dried. (Liebig.)
— The mass obtained by strongly igniting a mixture of 100 pts. of sul-
phide of antimony and 200 pts. of black flux, yields, after exhaustion
with water, a colourless filtrate, which yields nothing on cooling, but
on the addition of alkaline carbonates, deposits a dense kermes free
from oxide. (Liebig.) To this head likewise belongs the kermes prepared
by exhausting with water the antimony-slag which covers the metal
when reduced by cream of tartar and nitre. y>. 318, 2.)
When 100 pts. of sulphide of antimony are heated with 300 pts. of
cream of tartar, till the latter is merely carbonized, a kermes containing
oxide is produced, because the carbonate of potash formed exerts an
oxidating action on the antimony. (Liebig.) — Again, if 100 pts. of sulphide
of antimony are strongly ignited with 400 pts. of oream of tartar^ 56 pts.
348 ANTIMONY.
of metallic antimony are rednced, and the filtrate^ after exhausting the
mass with water, deposits nothing on cooling, and only a small quantity
of brick-red kermes on the addition of acids. (Duflos.)
A 'mixture of 100 pts. of sulphide of antimony, 12*5 pts. of sulphur,
50 pts. of carbonate of potash, and 4 pts. of charcoal, yields metallic anti-
mony; and the remainder dissolves almost entirely in boiling water, the
solution depositing 48*4 pts. of kermes, free from antimonic oxide. — With
25 pts. of sulphur, 100 pts. of carbonate of potash, and 8 pts. of charcoal,
9 pts. of metallic antimony are obtained ; and the residue dissolves in
hot water and yields 16 pts. of kermes free from oxide. ^Duflos.)
A mixture of 100 pts. of sulphide of antimony with 100 pts. of
sulphate of potash and 17 pts. of charcoal, yields, after fusion and sub-
sequent solution in hot water, from 83 to 100 parts of kermes. (Bucholz.)
Pagenstecher obtained with these proportions, 22 pts. of kermes of a very
bad colour, and containing 43 per cent, of oxide. Duflos likewise obtained
but one-third as much as Bucholz, and the kermes contained 2 2 '75 per
cent, of oxide. This large quantity of oxide arises from the charcoal not
being in sufficient quantity to convert the whole of the sulphate of potash
into sulphide of potassium. Hence the sulphuric acid is but partly decom-
posed, and the potash set free converts a portion of the sulphide of
antimony into antimonic oxide. (Duflos.) — ^A mixture of 100 pts. of
sulphide of antimony, 100 pts. of sulphate of potash, and 25 pts. of
charcoal, kept for some time at a red heat, yields 19 pts. of metaliic
antimony, and only 1 1 pts. of kermes free from antimonic oxide. Whence
it appears that, in this case also, the sulphantimonite of potassium is,
by prolonged fusion, partially resolved into sulphantimoniate^ of potas-
sium and metallic antimony. — With 100 pts. of sulphide of antimony,
50 pts. of sulphate of potash, and 12*5 pts. of charcoal, 6 pts. of metallic
antimony are obtained, together with a much larger quantity of kermes
than in the former instance, and free from antimonic oxide. (Duflos.)
The kermes prepared from sulphate of potash and charcoal forms a
gelatinous mass, similar to that prepared with black flux. (Liebig.^
By boiling sulphide of antimony with an aqueous solution of proto-
sulphide of sodium, and filtering, a solution is likewise obtained, which
deposits a similar dingy kermes, containing a large quantity of sulphide
of sodium. (Liebi^.) A kermes having the same composition, is like-
wise precipitated, by dissolving sulphide of antimony in a boiling aqueous
solution of protosulphide of potassium, and leaving the filtrate to cool.
The kermes thus prepared, after washing with cold water, imparts sul-
phide of potassium with a small quantity of sulphide of antimony to
boiling water, but cannot be entirely freed from sulphide of potassium
even by long boiling. (Soubeiran, J, Pharm. 27, 294.)
7. An aqueous solution of sulphantimoniate of sodium is boiled with
metallic antimony, till it is converted into a solution of sulphantimonite
of sodium, and then precipitated by an acid. — Inasmuch as the sulph-
antimoniate of sodium may be freed from every trace of arsenic by
crystallization, a kermes free from arsenic may be prepared from it,
provided also that the metallic antimony used is free from that impurity.
— A mixture of 100 parts of the crystallized compound, and 32 pts. of
washed antimony, is boiled for an hour or two with 1000 pts. of water
in a clean iron vessel, the water being replaced as it evaporates. The
filtrate is then diluted with boiling water, and nearly saturated with
dilute hydrochloric acid, whereupon 92 pts. of a fine reddish-brown
d
MINERAL KBBMES. 349
kermes, free from anfcimoiiic oxide, is deposited. (Duflos.^ — If the sulph-
antimoniate of sodium is not freed from adhering soda oy re-crystalliza-
tion, or if the mixture is exposed to the air while cooling, or if unboiled
water is used for diluting the filtrate or washing the product, the kermes
may contain antimonic oxide. But if the quantity of hydrochloric acid
added is less than sufficient to saturate the soda, so that the latter is
only converted into bihydrosulphate of soda, the precipitation of the
kermes is complete, and the hydrosulphuric acid conyerts any antimonio
oxide that may be formed, into sulphide of antimony. (Duflos.) — Formerly
Duflos filtered the boiling liquid, stirring frequently, into a solution of
16 pts. of common salt and 32 pts. of Glauber's salt m 640 pts. of water;
these salts accelerated the separation of the kermes, which amounted to
between 40 and 48 parts.
In the third, fourth, and fifth methods of preparing the kermes, it is
usual to boil the solution decanted from the precipitated kermes, with the
insoluble residue obtained on the previous boiling, as long as the filtrate
continues to deposit good kermes on cooling. — In the third, fourth, fifth,
and sixth methods, it is best to let the filtrate run into a large quantity o£
warm water, so that the kermes may be precipitated as the liquid cools,
—The kermes is washed, first by suosidence and decantation, and after-
wards on a filter with water freed from air by boiling, and still warm ;
because, according to Cluzel, water containing air gives rise to oxidation.
Duflos recommends washing with boiling not water, to remove the
antimonic oxide. H. Rose recommends the same treatment, in order
to remove the sulphantimoniate of potassium or sodium. The first
portions of the hot wash-water deposit kermes on cooling, because the
sulphide of potassium or sodium which is dissolved out, carries sulphide
of antimony with it. By long treatment with boiling water, however, a
portion of the kermes itself may be decomposed. ( Vid, infra.) Hence
the hot washing of Gay-Lussac and others cannot be employed. Liebig
purifies the varieties of kermes obtained by the fourth, fifth, and sixth
methods from the sulphide of potassium or sodium which they contain^
by digesting them in dilute tartaric acid, washing with cold water, and^
lastly, drying at ordinary temperatures.
Froperttes, — The kermes prepared by method 1 is a dense, fissured
mass, having a specific gravity of 4*15 and a conchoidal fracture; it
scratches grey antimony ore pretty strongly; has a dark leaden-grey
colour, and when in thin plates, exhibits a dark hyacinth-red colour by
transmitted light ; it yields a reddish-brown powder, rather darker than
that of ordinary kermes. (Fuchs.) Kermes obtained by process 2, is &
brownish -red, loosely coherent powder. The kermes containing antimonio
oxide, prepared by methods 3, 4, and 5, is a loosely agglomerated, reddish*
brown powder, which, when rubbed on paper, leaves a brownish-red streak,
(after washing with boiling water, a blackish-grey streak.) (Liebig.) —
The kermes, rich in sulphantimoniate of potassium or sodium, chained
by method 6, dries up in hard brown masses, having a conchoidal fracture
and yielding a brown powder. — When kermes, &ee from antimonic oxide,
(method 1 or 2,) is slowly cooled after fusion, it is wholly converted into
crystalline, radiated grey sulphide of antimony, which yields a blackish
powder. Kermes, containing antimonic oxide, yields, on the contrary, a
slag-like mass. (Fuchs.) Cold hydrochloric acid likewise converts
kermes, in a few days, into grey sulphide of antimony. (Proust.)
Pure mineral kermes must be regarded, with Berzelius, H. Rose, and
850 AMTDIONT.
Faobs, as amorplioas tersulpbide of antimony. Thia view ii confirmed
hj the following facts. Grey sulphide of antimonv is oonrerted bj fusion
and rapid cooling into the red sulphide. (Fuchs.) The kermes precipi-
tated from salts of antimonio oxide by hydrosulphuric acid is free from
antimonic oxide and water^ and exhibits the colour and other properties
of ordinary kermes. 1 53 pts. (1 At.) of antimonic oxide dissolved in a
boiling solution of cream of tartar and precipitated by hydrosulphuric
acid, yield a quantity of kermes amounting to 177*16 pts. alter drying in
ft sand bath; this when fused loses S'25 pts. of water, and leaves 173*91
pts. of grey sulphide of antimony. [The quantity of sulphide of antimony
produced should be 177 pts. (1 At.); the slight difference is probably due to
the presence of moisture in the antimonic oxide or to some incidental loss
in the process.! When 100 pts. of the kermes thus obtained and dried
in the sand-batn are dissolved in strong hydrochloric acid and precipitated
by water, the resulting powder of algaroth amounts to 86 '7 pts., while
100 pts. of grey sulphide of antimony treated in the same way yield
87 pts. Hence this kermes must consist of tersnlphide of antimony with
a small quantity of hydrosnlphate of antimonio oxide [or water] adhering
to it. (R. Phillips, Ann, Phil, 25, 378.) The kermes precipitated from
100 pts. of tartar-emetic by hydrosulphuric acid and dried in a water
bath, fuses when heated in a glass tube drawn out to a fine point, yielding
grey sulphide of antimony with loss of only 0'37 pts. (^ per cent.) of
yellowish water containing a small quantity of hydrosulphuric acid and
ammonia. [Robiquet, Gay^Lussac, and 0. Henry likewise obtained
ammoniacal water by heating kermes; probably the kermes absorbs
ammonia from the air.] The conversion of kermes into grey sulphide
of antimony takes place at a temperature considerably ImbIow redness,
commencing at the part most heated, and extending throughout the
whole mass; the portions adhering to the glass, howeyer, partly retain
their red colour. (Gmelin.) The kermes precipitated from tartar-emetic
by hydrosulphuric acid and dried in a water bath, loses when fused
only \ per cent, of hydrosulphuric acid, and is converted into grey
sulphide of antimony. (Geiger ^ Eeimann, Mag* Pharm. 17, 132.)
According to Robiquet, the kermes obtained from tartar-emetic should
yield 10 per cent, of water; but he does not state whether it must be
previously dried, or in what manner.
The kermes obtained by methods 3, 4, and 5 contains variable and
often large quantities of antimonic oxide (partly in combination with
potash or soda) and smaller quantities of sulpliantimoniate of potassium
or sodium; that prepared by method 6 does not contain antimonic oxide,
but a proportionably larger quantity of the latter compound, which gives
it its dingy colour. The antimonic oxide in the kermes is not chemically
combined with the sulphide of antimony, but merely mixed with it, in the
form of crystals, so that it is best detected by the microscope. It contains
little or no alkali. (H. Rose.) According to Liebig, however, the anti*
monic oxide is chemically combined, at least in part, with the sulphide
of antimony. Liebig nevertheless remarks that the whole of the antimonio
oxide and the compound of antimonic oxide and alkali may be removed
by prolonged washing, leaving pure sulphide of antimony. When kermes
containing antimonic oxide is fused in a stream of pure carbonic acid gas,
the mass does not yield a pure grey powder, but a powder having a tinge
of red or brown; very small quantities of antimonic oxide may however
be better recognized under the microscope than by this method. (H. Rose.)
A solution of cream of tartar boiled with pure grey sulphide of antimony
MINERAL KERMES. 351
or kermes free from oxide takes up but a mere trace of antimonic oxide—
just sufficient to exhibit a red colour on treating the filtrate with hydro-
sulphuric acid gas. From freshly precipitated and still moist kermes
containing antimonic oxide, the abore solution separates a large quantity
of the oxide, but after drying, not much more than from kermes originally
free from antimonic oxide. (H. Rose.) But, according to Buchner and
Pagenstecher, cream of tartar separates the antimonic oxide from kermes
containing that substance, after drying and even after fusion. Kermes
containing antimonic oxide likewise yields it to a hot solution of tartaric
acid or to cold hydrochloric acid. Kermes containing antimonic oxide
does not dissolye completely in the moist state in cold solution of potash,
but leaves a yellow mixture of the compound of antimonic oxide and
potash with sulphide of antimony. (Liebig.) If the kermes prepared by
method 6, whicti contains no antimonic oxide, but sulphantimoniate of
sodium, be dried at 65° (149° F.) it does not afterwards give off any
water at 140^ (284° F.*^; but when ignited in a current of hydrogen gas,
it evolves the water of crystallisation belonging to the sulphantimoniate :
the sulphur-salt undergoes no further decomposition, but remains in the
tube together with the reduced antimony. This kermes cannot be per-
fectly freed from the snlphur^salt, even by long-eontinaed washing with
hot water. (H. Rose.) In the moist state, it dissolves completely in cold
solution of potash; and the solution, on the addition of acids, evolves
hydrosulphuric aoid and deposits sulphide of antimony. (Liebig.) When
heated with tartaric acid, it gives off hydrosulphuric acid. (Liebig.)
The old theory, according to which kermes was regarded as hydro*
sulphate of antimonic oxide = SbO',3HS, — and the similar view of
Buchner and Qay-Lussac, which regarded it as a hydrate of tersnlphido of
antimony, combined in part with antimonic oxide, aie no longer tenable :
for, if either of these views were correct, kermes should yield considerable
quantities of water when heated.
Since the pure tersulphide of antimony obtained by methods 1 and 2
exhibits the red colour and the other characters of kermes, it follows that
the presence^ in variable proportions, of antimonic oxide, the compound of
antimonic oxide and alkali, sulphantimoniate of potassium or sodium, ''and
water, cannot be regarded as essential to the constitution of kermes.
These substances, inaeed, rather impair than heighten its colour. They
all however^^^espeoially the anttmonic oxide— increase the medicinal
action of the kermes. But, as the amount of antimonic oxide is very
variable, and may even differ when the same process is followed,
according to the temperature at which the solution is cooled, and the time
which elapses between the formation of the kermes and its sepaiation from
the liquid, &o., it is yet doubtful whether kermes free from antimonic
oxide would not be proferable for medicinal purposes — inasmudi, as like
the pentasulphide of antimony, it exerts a more powerful action than the
grey sulphide, in consequence of its finer state w division and amorphous
aggregation. And if in particular cases its power were required to be
increaaed, definite quantities of antimonic oxide or tartar-emetic might be
mixed with it. For this purpose, the kermes free Irom arsenic, prepared
by methods 2, a and 7 would answer better than the kermes 2, b; hut a
kermes of this kind free from oude may be meet readily prepared by
liebig^s process (p. 344).
[For analyses of kermes, chiefly of old date, and no longer satis-
Iftctory — especially as the hydzated snlphantimoniate of potasdum or
352 ANTIMONY.
sodiam vd£ overlooked — vid. Cluzel, Th^nard^ Robiquet, Bacbner,
Brandes, and 0. Henrj^ in tbeniemoira above quoted, p. 317.]
The following analyses are by H. Rose. — a. Kennes prepared by
method 3, by boiling with carbonate of soda; not very carefully-
dried. — b. Keruies (3) prepared by boiling with carbonate of potash. —
c. Kerme8(4) obtained by boiling with solution of potash, slightly washed
=2SbS' + KS,SbS* + 2Aq. — d. The same, after long-continued washing
with hot water = OSbS^ KS,SbS*.
a.
h.
c.
d.
Sb
67-81
• •■•
69-00
• •••
61-91
• •■•
6708
S
28-24
• • • •
28-41
• ■•>
30*26
•••a
29-44
Na
1-33
K
2-25
• •••
5*66
• ■••
3-48
HO
2-62
• •••
• *••
217
10000 .... 99-66 .... 100-00 .... 100*00
Decompositions of Mineral Kermes. — Kermes undergoes the same
decompositions a-s the grey sulphide of antimony; in the wet way, however,
they are more readily produced, in consequence of the greater mechanical
division of the kermes; the admixture of antimonic oxide may also
occasion slight differences. It exhibits the following peculiar reactions :
— 1. When kermes free from antimonic oxide is brou^t in contact with
a red-hot body in the open air, it becomes incandescent, and is converted
into sulphurous acid, antimonious acid, and antimonic oxide (Liebig.)— *
2. When recently precipitated kermes is boiled for a long time with a
large quantity of water, out of contact of air, it is completely resolved
into hydrosulphuric acid gas and antimonic oxide, which remains dissolved
in the water. If it be covered with a large quantity of water and exposed
to the air, it disappears entirely after a while, with the exception of a few
white flakes. (Geiger & Hesse, Ann. Fharm, 7, 19.) A, Vogel {J, Pliarm.
8, 148) likewise found that water repeatedly boiled with kermes, ex-
tracted antimonic oxide from it at each boiling. — 3. Kermes precipitated
from tartar-emetic by hydrosulphuric acid forms with ammonia, a co-
lourless solution^ which again deposits kermes on exposure to the air.
(Capitaine.) One part of kermes dissolves almost completely in 600 pts.
of aqueous ammonia. (Garot.) Kermes containing antimonic oxide, e. g.
that obtained by fusing 100 pts. of sulphide of antimony with 37*5 pts. of
carbonate of potash, .according to Berzelius* method (p. 345), is but y^rj
sparingly soluble in ammonia, either cold or hot, strong or dilute, so
that acids Tproduce but a scanty precipitate. The addition of milk of
sulphur renders the kermes more soluble, because it induces the formation
of pentasulphide of antimony, which is accordingly precipitated from the
solution by acids. Hence ammonia serves to detect the presence of
pentasulphide of antimony in kermes. (Geiger.) — 4. Freshly precipitated
and still moist kermes evolves heat when mixed with hydrate of potash,
and forms a lemon-yellow mass, from which water extracts sulphide of
potassium, sulphide of antimony, and a small quantity of the compound of
antimonic oxide and potash, leaving a yellow mixture (crocus containing
potash) of the latter compound with a compound of kermes and antimonic
oxide. (Berzelins.) From the filtrate, bicarbonate of potash throws down
a dense brown precipitate, consisting of a compound of 3 atoms of tersul-
phide of antimony with 1 atom of sulphide of potassium mixed with
antimonic oxide, from which the combined potash has been separated by
the carbonic acid. The supernatant liquid evolves hydrosulphuric acid
J
MINERAL KERMES. 353
on the addition of acids^ and deposits a small quantity of pentasulphide
of antimony, formed by the action of the air. With monooarbonate of
potash, the solntion solidifies, after a while, forming a brown jelly, in
conseqnence of the separation of the same compound. This compound is also
frequently precipitated in the gelatinous form, on diluting the liquid with
water, because the power of the sulphide of potassium to dissoWe the
sulphide of antimony is diminished by dilution. (Liebig.) The kermes
precipitated from hydrochlorate of antimonic oxide by hydrosulphurio
acid, is rapidly and completely dissolved by an excess of cold dilute
solution of potash, because the quantity of potash is sufficient to combine
with the antimonic oxide, and that of the water is sufficient to dissolre
the resulting compound. The colourless solution deposits the whole of
the antimony in the form of sulphide of antimony, on the addition of
hydrochloric acid, without evoMng any hydrosulphurio acid gas. Car-
bonate of ammonia added to the dilute solution likewise precipitates all
the antimony and sulphur, in the form of yellowish -red kermes; bicarbo-
nate of potash or soda acts in a similar manner, but the brownish-red
gelatinous precipitate which it throws down, consists of 3 atoms of
tersulphide of antimony, 1 atom of sulphide of potassium, and more or
less antimonic oxide; monooarbonate of potash or soda causes the liquid
to gelatinize after a while; the precipitate has the same composition.
When antimonic oxide or powder of algaroth is digested with a solution
of kermes in caustic potash, it separates the whole of the sulphide of
antimony, and forms a brown compound of sulphide of antimony, anti-
monic oxide, and potash. The solution rapidly absorbs oxygen from the
air and deposits brilliant crystals of antimonite of potash, after which
it contains sulphantimoniate of potassium. By boiling tersulphide of
antimony prepared in the moist way with solution of potash, a solution is
formed containing the same elements, but a larger proportion of sulphide of
antimony, which is deposited on cooling, in combination with a small
quantity of sulphide of potassium and antimonic oxide. The filtered
solution yields with bicarbonate of potash, a precipitate consisting of
sulphide of antimony with a small quantity of sulphide of potassium, but
free from antimonic oxide. The solution obtained by treating grey
• sulphide of antimony with solution of potash and filtering from the
residual crocus, behaves precisely in the same manner. (Liebig.) Kermes,
while still moist, likewise dissolves readily in solution 6f soda, but much
more slowly after drying, and forms a solution which is colourless and
transparent at first, but becomes turbid on exposure to the air, and
deposits a greyish-white powder of antimonious acid. (Geiger.) Kermes is
easily soluble in hydrosulphate of ammonia. (Buchner.) It does not
dissolve in the aqueous solution of sulphurous acid. (Berthier.) [For its
decomposition with calomel, vid. Mercury , vol. VI.]
Compounds of Tersulphide of Antimony, — a. With Antimonic oxide.
— b. With Basic Metallic Sulphides, forming salts called Sulphanti-
MONITES. In these compounds, the tersidphide of antimony plays the
part of a very feeble acid. Of the native compounds of this class, the
most abundant are those of tersulphide of antimony with the sulphides of
lead, iron, copper, and silver; they contain 1, 1^, 1|, 2, 3, 4, 6, or 9
atoms of the basic metallic sulphide, united with 1 atom of tersulphide of
antimony. — In these sulphur- salts, tersulphide of arsenic and tersulphide
of antimony replace eacn other, without any change in the crystaUine
form of the compound. (H. Boee^ Fo^g. 15, 414, and 587; 28, 435.) — i
VOL. IV. 2 A
354 ANTIMONY.
The oompoundt obtftined bj fiuion with giilphide of potaariam or
constitate the ordinary Liver ofatUinumjff Hepar antimonU, which, when
it contains but little sulphide of antimony, is perfectly soluble in hot
water, but when it eontains a larger quantity, dissolves, with partial sepi^
ratiou of the latter substance. On cooling, the solution deposits a portion
of the tersulphide, in the form of kermee, and the remainder is preci*
pitated by acids, even by oarbonic acid.
B. TetranUphide of J n^imony/— Formed when hydrosnlphnric acid
gas is passed through a solution of antimonious acid or antimoniate
of potash in hydrochloric acid. ^Benelius, H. Rose.)— Yellowish-red
powder, resembling sulphide of gold. — When heated, it evolves 1 atom
of sulphur, and is converted into grey sulphide of antimony. It
dissolves in boiling hydrochloric acid, and forms hydrochlorate of
antimonic oxide, hydrosulphuric acid gas being evolved and sulphur
deposited. (Berzelius.) Dissolves in ammonia, forming a yellow solution.
(Capitaine.) Probably a mere mixture of tersulphide and pentasnlphide
of antimony.
CilcnUtion. H. Rom.
8b 129 .... 66-84 66-U — 6655
48 64 .... S316 33-86 — 33-45
SbS* 193 .... 100-00 ~. 10000 — 10000
C. Pentasulpbide of Antimony, Anttmonic Sulphide, Svlph-
ANTlMONic Acid. — Golden Svlphuret of Antimony , Spieseglanuchwefel,
Goldichwefel, StUphur Antimonii auratum — Known only in the amor-
phous state. — Formation and Preparation, — i. By passing hydrosul-
phuric acid gas through a mixture of pentachloride of antimony with
water and tartaric acid, and then collecting the precipitate (H. Rose);
or by passing hydrosulphuric acid gas through antimonic acid diffused m
water. ^Berzelius.) — 2. An aqueous solution of the sulphide of an alkali-
metal, (e. g,, potassium, sodium, barium, calcium,) with sulphide of anti-
mony and sulphur, is prepared as in the formation of kenues, the quantity
of the sulphur being such, that the solution shall contain pentasulpbide of
antimony together with the protoeulphide of the alkali-metal. For this
purpose, sulphur is added to the mixture of tersulphide of antimony and the
alkaliuo ingredients, either during the fusion or the subsequent boiling with
water, in quantity sufficient to convert the tersulphide of antimony into
pentasulphide. Or the change may be effected by exposing an aqueous
solution of the alkaline sulphantiiuonite to the air, because the oxygen of
the air combines with a portion of the alkali-metal, and the sulphur thereby
liberated unites with the tersulphide of antimony. — From the solution of
sulphantinioniate of potassium, sodium, &c. thus obtained, the pentasul-
pbide of antimony is precipitated by the addition of a stronger acid,
. while the sulphide of the alkali-metal gives off hydrosulphuric acid, and
is converted into an alkaline salt. For example:
3NaS,Sb8» + 380»+3HO = 3(NaO,S03) + 3HS + SbS».
If an excess of sulphur be added to the boiling solution, pentasulphide of
the alkali-metal may be formed, in addition to the sulphantimoniate; and
in that case, the audition of an acid precipitates pentasulphide of anti-
mony from the latter compound, and milk of snlphur from the former,
whereby a paler golden sulphide is produced.
PENTASULPHIDE OF ANTIMONY. 365
a. Methodi involving the tue of $olventa onZy.— A oauetic alkali is
boiled with grey sulphide of antimony, sulphur, and water, and the
filtrate precipitated by an acid, which forms a soluble salt with the
alkali.^During the ebullition, antimoniate of the alkali and sulph-
antimoniate of the alkaline-sulphide are produced, and, according to
Mitsoherlich, in the following manner, taking soda for example :
18NaO + 8SbS? + 16S « 3(NaO, SbO*) + 5(3NaS, Sb8»).
The antimoniate of soda formed, remains for the most part undissolved
If we assume that the filtrate contains only 3NaS,SbS*, then with
3 atoms or more of SO' and the decomposition of 3 atoms of water, we
obtain the following products:
3Na0, SbS* + 3S03 + 3H0 = (3NaO, S0») + SbS* + 3H8.
But inasmuch as a small quantity of antimoniate of soda is also dissolved
from which the sulphuric acid sets the antimonic acid free, the latter is
also converted, by the decomposition of a portion of the disengaged
hydrosulphuric acid, into SbS^
a. A mixture of 1 pt of grey sulphide of antimony and 1 pt. of
sulphur is boiled with solution of potash or soda, and the liquid diluted
filtered, and precipitated by dilute sulphuric acid. (Westrumb.)
/3. A mixture of 1 pt. of sulphide of antimony and 1|^ of snlphur is
similarly treated (Gottling) ; the precipitate in this case is too pale.
7. A mixture of 72 pts. (8 At.) of ^ey sulphide of antimony, 13 pts.
(16 At. ) of sulphur, 48 pts. (18 At.) of dry carbonate of soda, and 52 pts.
(36 At.) of lime, is boiled and treated as above (18 atoms of lime would
be sufficient to separate the carbonic a<;id from the carbonate of soda; the
excess of lime is used merely to accelerate the decomposition). (Mit-
scherlich, J. pr. Chem, 19, 458.)
^. The method of displacement may also be employed, exactly as in
the preparation of kermes, (p. 344,) excepting that to the mixture of
2 pts. of finely powdered sulphide of antimony, 4 pts. of dry carbonate
of potash or soda, 6 pts. of slaked lime, and 8 pts. of washed sand, an
* additional 1 pt. of flowers of sulphur must be added. The filtrate, on
being precipitated with hydrochloric acid, yields a very brilliant golden-
coloured sulphide, the quantity of which is nearly equal to that of the
sulphide of antimony originally used. (Musculus, 1/. I^harm, 22, 241.)
I. A mixture of 1 pt. of sulphide of antimony with 1 pt. of sulphur,
2 pts. of lime, and 8 pts. of water, is boiled for an hour, the water
being replaced as it evaporates, and the filtrate precipitated by hydro-
chloric acid. The insoluble residue is again twice exhausted with water.
(Abesser, Eeperi, 9, 274.)
^. Boiling solution of potash is saturated with sulphur; and for every
7 pts. of sulphur dissolved, 13 pts. of powdered metallic antimony are
added, and the whole boiled for a quarter of an hour; the solution is then
diluted, filtered, and precipitated by sulphuric acid. A portion of sulphur
is however mixed with the pentasulphide, in consequence of the decom-
position of hyposulphite of potash. (Duflos.)
n. 55 pts. of protosulphide of potassium, obtained by igniting sul-
phate of potash with ^ its weight of charcoal, is dissolved in 165 pts. of
water, and the mixture boiled with 40 pts. of sulphur till it disappears.
The solution is then filtered from charcoal; boiled with 64 pts. of finely
2a2
356 ANTIMONY.
powdered antimony, till the metal is completely dissolred ; agun filtered,
dilated, and precipitated by solpburic acid. (Doflos, Br, Arch. 29^ 94 ;
31, 94.)
b. Methodic in whick the sulphide of antimony is Jlrst ignited with a
substance containing alkcUi.
aa. With an alkaline sulphate and charcoal. The charcoal conrerts
the sulphate into a metallic sulphide; and by subsequent boiling with
water and sulphur, the tersulphide of antimony is converted into penta-
sulphide.
a. A mixture of 6 pts. of grey sulphide of antimony with 16 pts. of
monosulphate of potash, and 3 pts. of charcoal is fused, and the resulting
mass boiled with 1 pt. of sulphur and 6 times its weight of water,— <tben
diluted, filtered, and precipitated with sulphuric acid. (Buoholz,
Trommsdorfi*.)
6. A mixture of 12 pts. of sulphide of antimony, 24 pts. of bisal-
phate of potash, and 4^ pts. of charcoal is fused at a gentle heat, with
freauent stirring, till a portion dissolved in water, supersaturated with
hydrochloric acid, and filtered, gives but a slight cloud with chloride of
barium ; the mass is then boiled with water and 3 pts. of sulphur for a
few minutes, till the black colour of the liquid changes to pure pale
yellow (by longer boiling, sulphide of antimony would be precipitated) ;
after which, the solution is filtered and precipitated by an acid. The
product is 15 pts. of pentasulphide of antimony. (Greiger, Repert 9,
251.)
7. Schlippe*s crystallized sulphantimoniate of sodium, prepared by
either of the methods given on page 385, is dissolved in water, and pre-
cipitated by sulphuric acid. (Schlippe, Schw. 33, 323.) The crystab
must be treated with cold water, (so that the kermes may be left undis«
solved,) and the solution afterwards filtered: hot water dissolves the
kermes also, and the resulting solution yields a darker preparation on the
addition of acids. (Jahn, N, Br. Arch. 22, 43.) By washing the crystals
of Schlippe's salt sevei-al times with cold water, reducing them to fine
powder, digesting them with 14 times their weight of cold water for
24 hours, with frequent stirring — filtering from kermes — and precipitating
as above — a sulphide is obtained, always having the same intensity of
golden colour. (Artus, J, pr. Chem, 27, 381.)
^. A mixture of 4 pts. of sulphide of antimony with 16 pts. of heavy
spar and 4 pts. of charcoal is ignited — the resulting mass boiled with
water and 1 pt. of sulphur — and the liquid filtered and precipitated by
hydrochloric acid. In this process chloride of barium is likewise
obtained. (Lampadius, Trommsdorfi^, i^. ^. 1,1,33.) Strong and con-
tinued ignition is necessary to ensure the success of the process : more-
over, unless the product is carefully washed, the pentasulphide of anti-
mony may contain a portion of the poisonous chloride of barium.
bb. Sulphide of antimony is fused with sulphur and an alkaline
carbonate, the product dissolved in water, and the filtrate precipitated by
an acid. In this case, either a decomposition into alkaline antimoniate
and sulphantimoniate of the alkali-metal takes place — ^similar to that
described by Mitscherlich, in the preparation by the method of solution,
(p. 355,)— -or, as in the formation of kermes : 3K0 and SbS' are resolved
into 3KS and SbO^ whereupon the dKS take up the remaining SbS^
which is converted into SbS' by the salphur.
The following proportions of grey sulphide of antimony, sulphar,
and carbonate of potash are recommended; 30:6:24. (Berzelius.)*—
PENTASULPHIDB OP ANTIMONY. 357
30 : 15 : 90. (Wieglieb.)— 30 : 30 : 50. (Westrumb.)— 30 : 60 : 120.
(Hirsobing.)
Properties. — Yellowisb-red powder or loosely agglomerated mass,
having a very feeble smell of sulphar and a sweetish sulphurous taste;
slightly emetic.
Calcnlatioii.
Sb 129 .... 61-72
5S 80 .... 38-28
8bS» 209 ~ 100-00
The pentasnlphide of antimony prepared by method 1, after being
dried at a gentle heat, contains neither hydrogen nor oxygen, but
consists of 1 atom of antimony combined with 5 atoms of sulphur; and
accordingly, when ignited in a current of hydrogen gas, it yields metallic
antimony, sublimed sulphur, and hydrosulphuric acid gas, but no water.
(H. Rose, Berzelius.) But according to Thenard, Geiger, and Buchner,
who have also given analyses of the pentasnlphide, it either contains
water already formed, or the elements of water, which are evolved in the
form of water on heating the compound.
DecompogUums, — 1. When heated out of contact of air — ^according to
Mitscherlich, even at the boiling point of sulphur — it gives off 2 atoms
of sulphur and is converted into grey sulphide of antimony. — 2. Swells
up in the fire and bums with flame (whereas kermes does not exhibit any
appearance of flame). (A. Vogel.)— 3. When it is exposed to the air in
the moist state for a few days, or in the dry state in as many months, a
very small portion of it is decomposed, yielding a small quantity of
autimonic oxide, which maybe separated by a boiling solution of cream of
tartar. The emetic properties of pentasnlphide of antimony may perhaps
be referred to this decomposition. (Otto, Ann, Pharm, 26, 88; Jahn,
If. Br, Arch, 22, 43.) — 4. Chlorine water and nitric acid render it paler,
probably by oxidation. (Pagenstecher, N, Tr, 3, 1, 391.)— 5. Cold strong
hydrochloric acid turns it grey (Geiger) [probably by resolving it into
grey sulphide of antimony and free sulphur]; but hot hydrochloric acid
dissolves it, producing hydrated terchloride of antimony, disengaging
hydrosulphuric acid, and separating sulphur. — 6. Pure pentasnlphide of
antimony dissolves in about 50 parts of cold dilute solution of ammonia,
leaving only a slight residue; on the" application of a gentle heat, it
dissolves completely. When it contains too small a proportion of sulphur,
kermes remains undissolved; if it contains an excess, sulphur is left
behind. Occasionally also a small quantity of antimonious acid is found
in the residue. The yellow amnion iacal solution when treated with acids,
again deposits the pentasnlphide without evolution of hydrosulphuric
acid. (Geiger, Mag. Pharm. 29, 241.) On dissolving the pentasnlphide
in ammonia, 3NH^S,SbS^ is formed, and antimonic acid left behind
(possibly mixed with a small quantity of sulphur). (Rammelsberg.) The
solution when boiled deposits tersulphide of antimony and free sulphur.
(Capitaine.) — 1, Golden sulphide of antimony dissolves rapidly in cold
solution of soda, forming a yellow liquid. (Geiger.) On boiling this
solution, antimoniate of soda is separated and a solution of sulphantimo-
niate of sodium formed. (Mitscherlich.) It dissolves in moderately strong
solution of potash with separation of antimoniate of potash, and m>m the
solution diluted with water, bicarbonate of potash precipitates brown
sulphantimoniate of potassium containing an excess of the sulphor-acid {see
368 ANTIMONY.
this compound); the filtrate, on being treated with adds, still erolrcB
hydrosulphuric acid and deposits a small qaaniitj of pentasulphide of
antimony. (Kammelsberg.) The solution in caustic potash is at first
transparent ; but if left overnight, deposits a crystalline precipitate (Jahn)
[of antimoniate of potash.] A cold solation of carbonate of potash does
not sensibly affect pentasulphide of antimony ; but on boiling, it eTolres
carbonic acid gas and behaves like caustic potash, viz. precipitating
antimoniate of potash and forming a solution of sulphantimoniate of
potassium. Baryta-water behaves like solution of potash, but separates a
larger quantity of antimoniate; the solution contains dBaS,SbS^ (Ram-
melsberg, Fogg. 52, 204 ) — 8. When immersed in an aqueous solution of
nitrate of silver, it turns brown, and on boiling becomes black, forming a
mixture of sulphantimoniate of silver and antimonic acid. A similar
efiect is produced with a solution of sulphate of copper. (Rammelsberg.)
-r-9. Decomposed by calomel (tnd. Cal'miel). — 10. Gives up sulphur to
boiling bisulphide of carbon and to boiling oil of turpentine. According
to M itscherlich, the bisulphide of carbon separates 2 atoms of sulphur
and leaves tersulphide of antimony; according to Rammelsberg, it extracts
only 2 per cent, after a quarter of an hour's boiling. — 11. When mixed
with saccharine solutions which are undergoing the vinous fermentation,
it disengages hydrosulphuric acid. (Pagenstecher.)
Compounds. — With Basic Metallic Sulphides, forming salts called
SuLPHANTiMONiATES. These are obtained : 1. By fusing together penta-
sulphide of antimony or a mixture of tersulphide of antimony and
sulphur, with the sulphide of an alkali-metal, or with charcoal and a fixed
alkaline carbonate or sulphate. If a strong heat be used, the addition of
sulphur to the tersulphide of antimony is not necessary, because, at a
high temperature, it is resolved into pentasulphide and metallic antimony.
— 2. By dissolving pentasulphide of antimony in aqueous solutions of the
alkaline hydrosulphates; if the faihydrosnlphates are used, half the hydro-
sulphuric acid is expelled. — 3. By dissolving pentasulphide of antimony
in the solution of a caustic alkali, or of an alkaline carbonate at a boiling
heat. In this process, antimoniate of the alkali is formed at the same
time, and is deposited almost completely in the form of a white powder.
— 4. By decomposing aoucous solutions of the terbasio alkaline anti-
moniates by a current of hydrosulphuric acid gas.
3KO,SbO< + 8HS « 3KS,SbS<-(-8HO.
If the alkaline mono-antimoniates are used, -f of the antimonic acid i«
precipitated in the form of pentasulphide of antimony. — 5. The com*
pounds containing the heavy metals are obtained by gradually adding a
solution of one of their salts to a solution of the sulphantimoniate of an
alkali-metal — ^the latter being in excess. When the heavy metallic salt
predominates, the precipitated sulphantimoniate and the remaining
metallic salt decompose each other, especially on boiling; and the pre-
cipitate formed in this manner, with lead, copper, or silver, contains
1 atom of antimony, 8 atoms of the other metal, 8 atoms of sulphur, and
5 atoms of oxygeui and is probably a mixture of 8 atoms of metallic
sulphide and 1 atom of antimonic acid : e. g. In the case of lead :
dPbS,SbS^ is first precipitated; and this, with 5PbO contained in the
solution, forms 8PbS + SbO*. Generally speakinff, these compounds
contain 3 atoms of the basio metallic sulphide with 1 atom of penta-
sulphide of antimony. Those of the alkali-metals are colourless or
OXY-SULPHIDB OF ANTIMONY. 359
yellow; snataiii a red heat withoat decomposition^ when heated ont of
contact of air; and are soluble in water, but not in alcohol. Their
aqueous solutions are slowly decomposed in the air, yielding carhonate
and hyposulphite of , the alkaline base and depositing kermes; all acids,
including even the carbonic, decompose tbem, liberating hydrosolphuric
acid and precipitating pentasulphide of antimony. According to Liebig,
they are not precipitated by carbonate of ammonia, nor, according to
H. Rose, by monocarbonate of potash or soda, a property which serves to
distinguish them from solutions of the tersulphide of antimony in snlphidee
of the alkali -metals. The compounds of pentasulphide of antimony with
heavy metallic salphides are yellow, reddish-yellow, brown, or black;
give off two atoms of sulphur and leave djMS SbS' when ignited out of
contact of air; and are for the most part insoluble in water. (Rammels^
berg.)
D. OxY-suLPHiDB OF Antimony. — a. Reffidus ArUimonii medicinalts,
'^EtUnmu Antimonii. — This compound is prepared by fu ing a mixture
of 5 parts of grey sulphide of antimony and 1 part of carbonate of potash,
and separating the upper stratum (consisting of snlphantimonite of
potassium) from the lower. Black mass, ha?ing a brilliant conchoidal
fracture, and jdelding a dark red powder. It appears to be a compound
of tersulphide of antimony with a very small proportion of antimonic
oxide.
b. Bed jinHmant^'Ore, ^- jlntimony-hlende. — (Ri^ihspieBsglanterz,) -«-
Occurs in needles, having the form of oblique rhombic prisms; i : m =
101^ Id'. According to Bemhardi (Br, Arck. 21, 4), it has the same
crystalline form as grey antimony-ore, and is moreover formed by its
decomposition, (vid, Blnm^ Pieudomorphosen, 172.) Specific gravity
= 4*6; softer than gypsum; cherry-red, slightly translucent, appearing
scarlet by transmitted light; has a diamond lustre; fuses very readily
before the blowpipe, sinking into the pores of the charcoal, and volatilizing
in dense clouds. When tjeated with hot concentrated hydrochloric acid,
it gives off hydrosulphurio acid. According to H. Rose {Pogg. 3, 452),
when ignited in a current of hydrogen gas, it yields hydrosulphurio acid,
water, and antimony. The same compound, containing 17 '94 per cent,
of sulphur, but of an orange colour, is sublimed when aqueous vapour is
passed over ignited sulphide of antimony. (Regnault.)
3Sb
68
30
Red
387
96
24
AnUwumy-crt.
76-33
H.
75-66
20-49
4-27
Rose.
to 74-45
„ 20-49
„ 529
8bO»,2SbSP
507
Or;
SbO»
2SbS?
«•••
10000 100-42
153 .... 69-82
354 .... 3018
,, 100-23
507 .... 10000
c. Antimonial Saffron, -^ Metallic Saffron. ^^Spieeeglanz^eafran.'^
Crow Aiiiimonii i, MetaUorum.
a. Free from Potcuk. — 1. Prepared by fusing a mixture of 3 parts of
antimonic oxide and 1 part of tersulphide of antimony, or a mixture of
sntimonio oxide, antimonions acid, or antimonic acid, with the proper
proportion of sulphur. (Proust.)— 2. By diffusing freshly precipitated
360 ANTIMONY.
kennes in acid bydrochlorate of antimcnic oxide, and adding water till
aotimonic oxide begins to separate; the antimonic oxide is taken up by
the kennes. (Berzelins.) Brownish -yellow. Converted into kermes hy
aqueous hydrosulphuric acid or hjdrosulphate of ammonia.
/3. Containing Potash. — When the mass obtained by igniting a mix-
ture of 1 part of grey sulphide of antimony with -^....1 part of carbonate
of potash or 1 part of nitre, is exbausted with hot water, a yellowish-
brown mixture remains consisting of oxysnlphide of antimony and the com-
pound of antimonic oxide and potash. According to Liebig, the quantity
of potash amounts to between 12 and 16 per cent. A similax' but yellower
crocus is obtained by treating the grey sulphide of antimony with boiling
solution of potash, or the red sulphide of antimony with the same
solution cold. Crocus fuses when beated, forming a transparent yellowish
glass. Dilute hydrochloric acid extracts the compound of antimonic
oxide and potash, and likewise separates part of the antimonic oxide from
the oxysulphide. (Berzelins.)
d. Glass of Antimony,— Spiessglanzglasiy Viirwn Antimonix. — This
compound is prepared by roasting sulphide of antimony on the iron hearth
of a reverberatory furnace, stirring constantly by means of a rake, and
regulating the temperature so that the sulphide may neither melt nor
burst into flame, but only give off a moderate quantity of fumes. The
heat is then gradually raised to low redness, till sulphurous acid ceaaes
to pass off, and the sulphide of antimony is converted into antimonions
acid. The antimony-ash, as it is called, is next rapidly fused in a
covered earthen crucible with about -^ of its weight of grey sulphide of
antimony, till its molten surface becomes bright like a mirror; it is
then poured out on a marble slab or a polished plate of copper. A
mixture of 100 pts. of the antimony-ash with 3*85 pts. of sulphide of
antimony, yields a reddish-yellow, transparent glass; with 4*39 pts., a
yellowish-red transparent glass ; with 5*28 pts., a hyaciuth-red transparent
glass; and with 6*69 pts., a dark hyacinth-red translucent glass. (Werner,
J. pr, Chem. 12, 53.) The antimonions acid is reduced by a portion of
the sulphide of antimony to antimonic oxide, with evolution of sulphurous
acid, and in this form combines with the remaining sulphide of antimony.
Or again, the roasting may be stopped before the whole of the sulphide
of antimony is decomposed, in which case no addition of sulphide is
required previous to fusion; but then it is more difficult to ensure the
proper proportions. The mixture should be stirred with a pipe-stem,
because when iron is used, it is apt to contaminate the glass. According
to Proust, this compound may be prepared by fusing together 8 parts of
antimonic oxide and 1 part of sulphide of antimony, or by fusing either of
the three higher oxides of antimony with a quantity of sulphur smaller
than that which is required to form crocus of antimony.
Brilliant; appears reddish-black by reflected, and dark hyacinth-red
by transmitted light. — Contains, according to Proust, 88*9 per cent, of
antimonic oxide and 11*1 of sulphide of antimony; according to Soubeiran
(J. Pharm. 10, 528) 91*5 per cent, of antimonic oxide, 1*9 of sulphide of
antimony, 4*5 of silica, and 3*2 of ferric oxide. — ^When treated with acids,
it gives up antimonic oxide; with hot hydrochloric acid it evolves hydro-
sulphuric acid gas. — Olass of antimony may be fused with silica (e.g. from
the crucible) and with glass, the products being hyacinth-coloured glasses.
£. SiTLPHiTB OF Antimonic Oxidb. — Formed when antimonic oxide
is digested with aqueous solution of sulphurous acid, or when sulphurons
SULPHATE OF ANTIMONIC OXIDK. 361
acid ffas is passed through acid hydrochlorate of antimonic oxide.
Insolnble in water. (Berzelius.)
F. Sulphate op Antimonic Oxide. — When antimony is heated with
oil of vitriol, the products are sulphurous acid^ sublimed sulphur, and a
white anhydrous residue, which is probably the salt c.
a, DisulphaU 9 — 1. Formed by digesting the above-mentioned white
residue in cold water, whereby sulphuric acid and a small quantity of
antimonic oxide are separated. — 2. By dissolving 1 part of the white
residue in 2 parts of water, enough oil of vitriol being added to render
the liquid clear, and then precipitating by water. (Brandos.) White
powder containing 3 per cent, of water. When boiled with water, it loses
the greater part of the sulphuric acid, so that 99 parts of antimonic oxide
retain no more than 1 part of sulphuric acid. (Brandos.) H Peli^ot has
since examined this compound and shown that it is really a disulphate.
(Ann, Chim. Phys, 3, 20, 283.) T
5. Monosnlpkate. — Formed by reducing the salt e to powder, agitating
with alcohol, collecting the resulting powder on a filter, and drying it.
(Brandos.)
IT c. Bintlphate, — Obtained by treating powder of algaroth with
fuming sulphuric acid; crystallizes m small brilliant crystals. (Peligot.) IT
d. Termfpkate. — 1. The white residue obtained by heating antimony
with oil of vitriol) — 2. Crystallizes in small needles from a solution of the
white compound in excess of sulphuric acid. (Brandes.) — The white resi-
due, when ignited, evolves sulphurous acid and oxygen gas (Oay-Lussac),
together with anhydrous sulphuric acid (Bussy), and often yields a subli*
mate of antimonic oxide in the form of needles. (Bucholz.) When ignited
in a current of hydrogen gas, it 3rields a mixture of antimony, sulphide of
antimony, and antimonic oxide. (Arfvedson, Fogg. 1, 24.) The isalt is
converted by water, either into a or into nearly^ pure antimonic oxide,
according to the temperature of the water.
% e. QuadrofulphaU. — When powder of algaroth is treated with con-
centrated sulphuric acid (S0^ HO) hydrochloric acid gas is evolved, and
quadrosulphate of antimony obtained in needles, which can only be dried
by keeping them for a long time on a piece of burnt clay in vacuo over
oil of vitriol. (Peligot.) T
By digesting c in strong sulphuric acid, a sulphate is fonned contain-
ing excess of acid.
At. a, Jgnittd, Brandes. Peligot.
SbO> 2 .... 306 .... 88-44 9072 .... 886
S0» 1 .... 40 .... 11-56 9*28 .... 11 4
i .... 346 .... 100-00 ZZ 100-00 .... 100-0
At. h. Brandes.
8bO» 1 .... 153 .... 79-3 78-10
S0». 1 .... 40 .... 20-7 21-25
1 .... 193 .... 100-0 99-35
Peligot.
At, e. (1) (2)
SbO» 1 .... 153 .... 65-6 630 .... 64-3
80» 2 .... 80 .... 34-4 37*1 .... 350
i Z. 233 .... 1000 ~, 100-1 .... 99-3
362 ANTIMONY.
At. d.
8bO» 1 .... 153 .... 5604 564
80» 3 .... 120 .... 43-96 432
i ~. 273 .... 100-00 ZZ 99-6
Peligot.
At. •. (1) (2)
flbO» 1 .... 153 .... 48-8 60-2 .... 44-3
80* 4 ... 160 .... 51-2 51-9 .... 53-1
t^.
1 .... 313 .... 1000 1021 .... 97-4
Antimonioaa aoid is spftringlj solable in oil of ritriol. (Beneliut.)
Antimokt xkb Sbleniuv.
A. Selbnidis of Antimont. — The two elemeots readilj nnito on the
application of heat, the temperature daring oombination froqaently rising
to redneeB. The product is a lead-grev maas, vrhich fuaea at a rea heat —
has a crystalline fracture — and when neated in the air, gives off a small
quantity of selenium and becomes covered with a vitreous slag. A
similar compound is precipitated from a solution of tartar-emetic by
hydroselenic aoid gas. (Benelius.)
B. Oxr-BELEMIDB OF Antimont. — The two compounds fuse readily
together, yielding a brownish-yellow^ translucent^ vitreous mass^ like
glass of antimony. (Berzelius.)
ANTmOKT AND lODINV.
A. Tbriodidb of Antimont. — The two elements unite at ordinary
temperatures, the combination being attended with great rise of tempera-
ture and evolution of iodine vapour, and even with explosion, if large
quantities are used. — On one occasion, when a few ounces of the mixture
were put into a retort, the retort burst with a loud report, even before
heat was applied, and the compound was thrown up to the ceiling of the
laboratory. ^Brandos, N, Br. Arch. 21, 319.) — >\'hen powdered antimony
is added to iodine, the first portions render the iodine fluid; after which
the antimony must be gradually added till saturation is effected. (Semllas,
J, Pharm, 14, 19.) Or a mixture of 129 parts (1 At.) of antimony, and
not quite 378 parts (3 At.) of iodine is heated in a retort, and the resulting
compound separated from the excess of antimony by distillation. (Brandes,
N. Br, Arch, 14, 135; 17, 283.) — Crystalline, brownish-red mass, which
yields a oinnabar>red powder. (Serullas.) Has a semi-metallic lustre;
becomes blackish-red every time it is heated; and at higher tempera-
tures softens, and afterwards fuses to a dark garnet-red liquid, which
evolves violet-red vapours at first, but afterwards, when more strongly
heated, gives off scarlet vapours, and either sublimes in the form of a scarlet .
film, or distils over in the liquid state. (Brandes.) The distillation takes I
place at a moderate heat (Serullas), a little above the boiling point* '
(Berthemot.)
CalcuUtioD. Brandes.
8b 129 .... 25-44 25-5
31 378 .... 74-56
8bl« 507 .... 10000
lODO-SULPHIDB OF ANTIMONY. 363
Nitrio acid is coloured yellow by iodide of antimony; if heat be
applied, violent action takes place, and iodine is set free. — ^When iodide
oi antimony is treated with oil of yitriol at ordinary temperatures, the
iodine is separated with great rapidity. — Hydrochloric acid dissolves
iodide of antimony, forming a yellow liquid which is precipitated white
by water. — When it is mixed with cold solution of ammonia, hydriodate
of ammonia is formed, with separation, first of a yellow, and afterwards
of a yellowish -white powder. (Brandos. )— Water resolves iodide of anti-
mony into yellow pulverulent oxy-iodide of antimony and a reddish yel-
low liquid, which may be regarded as solution of iodide of antimony in
aqueous hydriodic acid, or as an aqueous solution of acid hydriodate of
autimonic oxide. — In this case, two-thirds of the iodine are separated by
the water. (SeruUas.) Spirit containing 80 per cent, of alcohol behaves
like water; the yellow powder separated by it amounts to one-fourth of
the iodide of antimony used; the reddish -yellow liquid, when dLbtilled,
yields free iodine and a second reddish-yellow liquid, having the odour
of horse-radish, and leaves a brownish-red subaianoe containing 33*4 per
cent, of antimony. (Brandos.)
B. Hydrated Oxy-iodide op Antimony or Basic Hydriodate of
Antimonio Oxide. — The pale yellow powder, separated by decomposing
teriodide of antimony with water, has this composition. — Even when
dried at a temperature at which it begins to decompose, it still gives off
water if more strongly heated, and likewise yields a sublimate of iodide of
antimony and a residue of antimonic oxide. It may be deprived of the
whole of its iodine by repeated washing with small quantities of water.
(Serullas.) — If it be washed with boiling water till the filtrate no longer
reddens litmus, and the washing still further continued, it is partially
decomposed, and the water deposits micaceous scales on cooling. When
this compound is boiled in water with zinc or iron (tin acts less readily),
antimony is reduced in the form of a black powder. Alkalis and mag«
nesia, or their carbonates, separate antimonic oxide and dissolve an
iodide of the alkali metal. (Berthemot.) — Brandes & W. Bott^r regard
the compound as SbP, because in their analysis they obtained 61 77 parts
of antimony to 34*76 parts of iodine, — and on heating the compound in a
narrow glass tube, teriodide of antimony was sublimed, and metallic
antimony left, together with a mere trace of antimonic oxide [the author
obtained as residue, a yellow glass consisting of antimonic oxide with
a small quantity of iodide of antimony] ; nevertheless they add, that when
digested with potash, the compound left a perfectly white powder, and
that it dissolved completely in a warm solution of tartaric acid.
C. Solution of Iodide of Antimony in Hydriodic Acid, or Acid
Hydriodate of Antimonic Oxide — The reddish-yellow liquid formed
in the decomposition of teriodide of antimony by water. When 1 part of
the teriodide is decomposed by 6 parts of water, the resulting solution
contains 6*17 per cent, of antimony and 90*83 of iodine; on further dilu-
tion, a reddish-yellow powder is deposited. This compound, when dia*
tilled, yields free iodine and a reddish-yellow and subsequently a black
distillate, while reddish-brown teriodide of antimony is left in the retort*
(Brandes & W. Bbttger, N. Br. Arch. 17, 283.)
D. Iodo-sulphide of Anttmont. — On exposing a dry and intimate
mixture (reddish-brown in colour) of equal parts of iodine and sulphide
of antimony to a moderate heat in a retort placed in a sand bath, the
364 ANTIMONT.
new compoQDd is eyolved in red yaponn, and deposited in the form of a
fioblimate. — The following mixture may also be sublimed: 24 parts of
antimony with 9 parts of salphur and 68 parts of iodine; or 2 parts of
antimony with 9 parts of iodide of snlphnr; bnt in this case, crystallized
sulphur is likewise mixed with the sublimate.—- Brilliant, transparent,
blood-red scales and needles, which fuse at a sentle heat, and volatilize in
red vapours at a lower temperature than iodide of antimony, and without
decomposition. Has an unpleasant odour, and a nanseons, pungent taste.
Calculation. Henry 9c Garot.
Bb 129 .... 23-24 232
38 48 .... 8-65 8-8
31 378 .... 68-11 66-4
Sb8»,P.> 555 .... 10000 ~. 98-4
When strongly heated in the air, it is resolved into iodine, snlphnr,
sulphurous acid, metallic antimony, and antimonic oxide which volatilizes.
It dissolves in sulphuric acid, nitric acid, hydrochloric acid, and aqua-regia,
with separation of the iodine, and partly also of the sulphur. — Chlorine
converts it into chloride of iodine, chloride of sulphur, and chloride of
antimony. — Hydrosulphuric acid and sulphurous acid gas do not affect it
— When mixed with water, it is resolved into hydriodic acid which dis-
solves, and an insoluble orange-yellow mixture of sulphur, antimonic
oxide, and a small quantity of iodide of antimony. Solution of ammonia
separates hydriodic acid in a similar manner : so likewise do alcohol and
ether, excepting that they also dissolve a small onantity of sulphur. The
fixed alkalis likewise cause decomposition. (0. Henry & Garot^ J. Pharm,
10, 511; also Schw. 43, 53.)
E. Iodide op Antimony + Sulphide op Antimony. — From a very
dilute solution of iodide of antimony in hydrochloric acid, hydrosulphuric
acid precipitates a mixture of iodide and sulphide of antimony, fiom
which the iodide of antimony is sublimed by heat. (Johnston, N, Fdinb,
Phil J. 18, 43.)
Antimony and Bromine.
A. Terbromide op Antimony. — Antimony takes fire when brought
in contact with bromine, the metal running about iu glowing fused
globules on the surface of the bromine. (Balard, Serullas.) Bromide of
antimony is prepared iu a similar manner to bromide of arsenic (p. 283),
but the neck of the retort must be kept hot during the distillation to pre-
vent stoppage. — Colourless mass crystallized in needles, which fuse at 94°
and boil 270*^. — Absorbs moisture m>m the air. Water instantly resolves
it into hydrobromic acid — ^which, if a large quantity of water be added,
does not retain a trace of antimonic oxide — and basic hydrobromate of
antimonic oxide. (Serullas, Ann, Chim, Phys, 38, 322; also Pogg, 14, 112.)
— Cold nitric acid does not decompose terbromide of antimony, but at a
boiling heat, resolves it into bromine vapour and a white insoluble powder
(nitrate of antimonic oxide); oil of vitriol likewise does not disengage
bromine vapour unless aided by heat. (Lowig, Repert, 29, 266.)
Calculation, aocordiDg to Serullas.
Sb 129-0 35-42
3Br 235-2 64-58
SbBi» 364-2 ZZ 100-00
i
TERCHLORIDB Of ANTIMONY. 365
B. Htdbated Oxt-bromide op AKrncoinr, or fiAsic Htdbobromatb
OP Antimonig Oxide. — Prepared by decomposing terbromide of antimony
bj water. When dried at a temperature at which decomposition com-
mences, it still retains water, which, at a higher temperature, is evolved
together with terbromide of antimony, while antimonic oxide is left
behind. By washing it repeatedly with small quantities of water, the
whole of the bromine may be removed. (Serullas.)
Antimony and Chlorine.
A. TbbchIiORIDb op Antimony. — Butter of Antimony ^ SpieuglanZ"
butter, Butyrum Antimonii, Catuticum antimoniale.'^l. Terchloride of
antimony is formed by passing chlorine gas over heated sulphide of anti'
mony, and separating the chloride of sulphur, produced simultaneously
with the chloride of antimony, by volatilization at a gentle heat. (H. Rose.)
— The affinity of the chloride of sulphur for terchloride of antimony pre-
vents the latter from combining with more chlorine, and thereby passing
into pentachloride of antimony. (Mitscherlich.) — 2. By distilling 3 parts
(1 At.) of antimony with 8 parts (nearly 3 At.) of corrosive sublimate.
(Basil Valentine.)
Sb + 3HgCl » SbCls + 3Hg.
If the heat be not kept very moderate, mercury likewise passes over into
the receiver. — 3. By distilling 2 parts (1 At.) of sulphide of antimony
with 5 parts (or better with 4*6 pts.=3 At.) of corrosive sublimate.
SbS^ + aHgCl » SbCl> + 3HgS. (8ch. 45.)
Towards the end of the process, Cinnabaris Antimonii is sublimed. —
4. Acid hydrochlorate of antimonic oxide is moderately heated in a
retort, till the water and excess of hydrochloric acid are driven off,
and the residue has acquired the consistence of butter; the receiver
is then changed, and the terchloride of antimony distilled over at a
higher heat. — Glauber used for this purpose a solution of flowers of
antimony in hydrochloric acid. — Robiquet (Ann. Chim, Fhys, 4, 105,
also Schw. 19, 189,) dissolves 1 part of antimony in a mixture of 4 parts
of hydrochloric acid and 1 part of nitric acid ; the latter must be added
in small successive portions, and a gentle heat applied. If too much
chlorine is given off on evaporation, the nitric acid is in excess, and an
additional quantity of antimony and hydrochloric acid must be added.
It is always advisable to have a portion of metallic antimony at the
bottom of the retort. — G&bel (Br, Arch, 2, 216), treats 1 part of sulphido
of antimony with 3 pts. hydrochloric acid of specific gravity 1'2, and
|- pt. nitric acid of specific gravity 1*55 — decants the liquid from tho
sulphur — and distils till half has passed over. — Brandos (N. Tr. 3, 1, 261,
and Repert, 11, 289), treats 1 part of sulphide of antimony with a mixturo
of 5 pts. of strong hydrochloric and 1 pt. of nitric acid; decants the solution
thus obtained ; digests the residue in a mixture of \ pt. hydrochloric and
\ pt. nitric acid ; and distils the two liquids together, whereby, after the
watery portion has passed over, 1 -J- pt. butter of antimony is obtained. —
Geiger & Reimann (Afag. Pharm, 17, 126), gently heat 1 pt. of sulphido
of antimony with a mixture of 3 pts. hydrochloric acid, of specific
gravity 1*16, and 0*72 pt. nitric acid, of specific gravity 1*171, till the
solution, which is at first yellow, becomes oolourless^ and then decant
366 ANTIMOMT.
it. An exoeM of nitric acid 10 to be ayoided, becaiuie it produoM aati-
monic acid on evaporation. — Liebig diBaolves 1 pt of sulphide of nntimony
in 3 ptB. of hot faming commercial hydrochloric aeid; evaporatae the
decanted solution, till a drop solidifies when placed upon cold metal ; and
then distils it from a retort^ changing the receiver as soon as the distillate
solidifies on cooling. — 6. By distilUng sulphate of antimonie oxide, or
some substance capable of producing it, with common salt.
Sb03,3SO» + 3NaCl = SbCl» + 3(NaO,SO»).
Berzel ins' evaporates sulphuric acid with antimony or antimonie oxide,
and distils the residue with twice its weight of common salt. — A mixture
of 1 pt. of roasted sulphide of antimony with 3 pts. of decrepitated
common salt is distilled with 1^ pt of fuming oil of vitriol. {OrdL Cha^,
J. 6, 76.) — Glauber and Becher distil 1 pt. of sulphide of antimony with
2 pts. of common salt and 4 pts. of burnt sulphate of iron . Rolfink uses
equal parts. — In distilling butter of antimony, it is necessary to use a
wide-necked retort; if, however, it bacomes stopped up by the solidi-
fication of the compound, the solid mass must be melted by holding a hot
ooal under it
Translucent, colourless, 'solid, crystalline msss, which at 72° (Capi-
taine), fuses to a colourless or yellowish oil; boils at 197*8° (H. Davy), at
230"^ (Capitaine); emits scanty white fumes in the air; is very cor-
rosive.
Calcalation. J. Davy. Oobell. H. Rose.
Sb 129-0 .... 54-85 .... 6042 ... 5498 .... 53-27
3Cl 106-2 ... 4515 .... 3958 .... 4502 .... 46*73
SbCl» 235-2 .... 10000 Z 10000 Z 10000 Z 10000
When distilled with an equal weight of sulphur (whereby a small quan^
tity of butter of antimony is volatilized undecomposed), it is resolved into a
volatile liquid, [pentdchloride of antimony or chloride of sulphur?] which
distils over, and grey sulphide of antimony which remains in the retort
(A. Vogel, Schw. 21, 70.) — When treated with hot nitric acid, it evolves
chlorine gas, and leaves a white powder (antimonie acid). — It is not
decomposed by cold oil of vitriol ; but when boiled with that liquid, it is
resolved into hydrochloric acid gas, and sulphate of antimonie oxide
which remains in the form of a white mass. (A. Vogel.) — When heated
with sulphocyanide of potassium, it yields vapour of bisulphide of carbon,
tetrasulphide of antimony, and mellonide of potassium. (Liebig.) — It
gradually absorbs moisture from the air, and deliquesces to a turbid
liquid. — 100 parts of terchloride of antimony, exposed for 70 days to air
saturated witn moisture, absorb 110 parts of water, but no more after-
wards; during the absorption, the chloride first deliquesces and then
deposits a white precipitate. (Brandes, Schw. 51, 437.) — It is only when
free hydrochloric acid is present, that the chloride deliquesces without
turbidity. (H. Rose, Pogg, 55, 551.) When small pieoes of terchloride
of antimony are laid on mercury, they revolve about for some time, till
the mercury becomes covered with a film of aqid hydrochlorate of anti-
monie oxide (Jacquelain, Ann, Chim. Fhy», 66, 123.) — When chloride
of antimony is mixed with a large quantity of water, it is resolved
without perceptible rise of temperature, into oxy-chloride of antimony,
which is precipitated, and acid hydrochlorate of antimonie oxide, which
dissolves.
OXT-CHLORIDB OF ANTIMONY. 367
Terohloride of antimony combines wiUi ohloride of inlphnr. It does
not absorb hjdrochlorio acid gas,
B. OxYHJHLO&iDB OF Antimony. — Po/wder of Algaroth^ PulvU Alga-
roth s. angelicuB, Mercurius irt/is.-i— This compoond is precipitated on
adding water to terchloride of antimony or to acid hydrocnlorate of anti-
monio oxide. It may also be obtained by mixing 1 pt. of glass of anti-
mony with 3^ pta. of common salt, 2^ pts. of oil of vitriol, and 2 pts. of
water — cheating the liquid for 12 hours nearly to the boiling point —
diluting the eolation with water till a precipitate begins to appear —
then filtering, and precipitating with more water. (Scheele^ Bucholz.)
Instead of common salt and oil of vitriol, strong hydrochloric acid may
also be used. Liebiff boils strong commercial hydrochloric acid with
finely powdered sulphide of antimony to saturation ; then adds enough
water to precipitate a small quantity of powder of algaroth, whereby the
hydrosulphuric acid present in the liquid is carried down in the form of
sulphide of antimony ; and lastly, filters and precipitates by a further
addition of water.
The precipitate is washed with a yery small quantity of cold water.
When the snow-white bulky precipitate is collected on a filter imme-
diately after its formation, and then washed and dried, it yields a powder;
but if it be allowed to stand under the liquid for two or three days, it
forms a greyish- white mass, consisting of small prisms. The crystals are
dried between folds of bibulous paper; if washed with water, they
become dull in consequence of superficial decomposition. (Johnston, JV,
Edinb, Phil. J, 1 8, 40; also J. pr, Chem. 6, 55 ; Malaguti^ Ann. Chim.
Pkys. 59, 220; also J.pr. Chem. 6, 253.) IT Peligot {Ann. Chim. Phys.
3, 20, 283), regards the oxy-chloride obtained by treating butter of
antimony with cold water, as SDC10^ and the compound which is deposited
in dense brilliant crystab, on boiling terchloride of antimony or hydro-
chlorate of antimonic oxide with water, and subsequent cooling, as
2SbC10». IT
White powder, or fine, greyish-white, highly brilliant needles,
(Bnoholz, Taschenb. 1806, 18), which, according to Johnston & Miller,
are oblique rectangular prisms, having the obtuse summits replaced
by planes.
Calculation. Johnston. Duiloi. Bucholx. Phillips
6Sb 774-0 .... 77-38 .... 76-82 .... .... .... 77-98
3C1 106-2 .... 10-62 .... 11-25 .... 10'37 .... 1005 .... 7-80
150 1200 .... 1200
SbCl>,oSbO».... 1000-2
.... 100-00
PeUgol
1.
Or:
Calculation.
(1)
(2)
2Sb
258-00
• •■•
77-3
76-5 ....
76-8
a
35-41
■ •■■
JO-6
Ill ....
11*4
30
2400
• •••
12-1
2SbClO»
317-41
*«fl*
100-0
Or:
Halagoti.
GrooTelle.
SbCl'
235-2
■ fl«a
76-48
74-51
82
5SbO»
765-0
• «■«
23-52
25-70
.... Is
i p... f m .
1000-2
•
10000
... 100-21
.... 100
m % m
The slight excess of chlorine obtained by Johnston probably arose
from not washing the product. (Johnston regards the powder of algaroth
368 ANTIMONY.
aa 2SbCl'-f 9SbO*}; Bacholz and Groayelle (Schw. SS, 431), and espe*
ciallj Phillips (PhU, Mag. Ann, 8, 406; also Br. Arch. 39, 40), found
too little chlorine, doubtless from orer-washing ; Groarelle's analysis
gives the formula SbCl',7SbO'. — Powder of algaroth does not lose weight
at lOO**, and only 0*38 per cent, of water by ignition with dry carbonate
of soda. (Johnston.)
Powder of algaroth foses when strongly heated, and is resolved into
terchloride of antimony which distils over, and a residue of antimonio
oxide. (Bergman.) The crystals decrepitate during the decomposition.
(Johnston.) When the powder is strongly heated in a glass tube, the
antimonio oxide likewise volatilises, so that nothing remains. (H. Rose.)
— When ignited with sulphur, it gives off sulphurous acid [and penta-
chloride of antimony or chloride of sulphurf J and is converted into
110*5 percent, of grey sulphide of antimony. (Grouvelle.) By boiling
with nitric acid it is converted into antimonio oxide. (Bucholz.) By
long continued washing with hot water, the whole of the chlorine is
removed in the form of hydrochloric acid, and pure antimonic oxide leflt
on the filter. (N. E. Henry, J. Pkarm. 12, 79; Duflos, Sdiw. 67, 268;
Malaguti.) The chlorine is likewise completely removed by aqneons
solutions of the alkaline carbonates.
When powder of algaroth is precipitated from a liauid containing
hydrosulphuric acid, — e. g., from a solution of grey sulphiae of antimony
in strong hydrochloric acid, by diluting with water after decantation —
it forms a bulky yellowish precipitate, which aggregates in red crystals,
if kept under the liquid for a few days. These crystals consist of powder
of algaroth mixed with a variable quantity, at most 2 per cent., of
sulphide of antimony. (Malaguti.)
C. Solution of Htdrochlorate of TBRCHLORtDE of Antimony or
Acid Htdrochlorate of Antimonic Oxide. — Liquor Stibii muriatiei
of the Fkarmac. Bar. — 1. Prepared by decomposing terchloride of anti-
mony with a small quantity of water, and decanting the liquid from the
powder of algaroth thereby produced. This solution is the old Spiritus
VUrioli pkilosophicus, — 2. By dissolving terchloride of antimony in
aqueous hydrochloric acid; the solution being effected without any preci*
pitation. — 3. By dissolving sulphide of antimony in strong boiling hydro-
chloric acid.— 4. By dissolving antimonic oxide, glass of antimony, or
crocus of antimony, in strong hydrochloric acid, and decanting or distilling
the liquid. — 5. By the same process as that given for the preparation of
terchloride of antimony under (5), either without distilling the resulting
solution, or distilling it without changing the receiver, so that the aqueous
hydrochloric acid which first passes over, may mix with the subsequent
distillate of terchloride of antimony. — 6. By distilling a mixture of glass of
antimony, crocus antimonii, or sulphide of antimony, with common salt and
dilute sulphuric acid, the retort being heated nearly to redness towards the
end of the process ; e. g. \ pt. of glass of antimony, 4 pts. of common salt,
3 pts. of oil of vitriol, and 2 pts. of water, (Gbttling) ; — 1 pt. of crocus
of antimony, 3 pts. of common salt, 2 pts. of oil of vitriol, and 1 pt. of
water {Pharmac. Boruss., edit. 3) ;~2 pt«. of grey sulphide of antimony,
3 pts. of common salt, 2 pts. of oil of vitriol, and 2 pts of water. The
hydrosulphuric acid which passes over, re-precipitates a small quantity of
sulphide of antimony from the distillate. — 7. By distilling to dryness a
mixture of 8 pts. of antimony, 14 pts. of common salt, 5 pts. of peroxide
of manganese, 12 pts. of oil of vitriol, and 12 pts. of water. (Brandos.)
PENTACHLORIDB OP ANTIMONY. 369
Yellowish liquid, of specific grayity, 1*35 ....1*50; fames when con-
centrated, and when considerably dilated, deposits a large quantity of
powder of algaroth.
D. SoLUTioNOP Acid Hydrochloratb op Antimonious Acid. — The
hydrate of antimonious acid dissolves sparingly in strong hydrochloric acid.
Ilie pale yellow solation is precipitated white by water, after a short
time; with a large excess of water, however, no precipitation takes place.
E. Pentachloride of Antimonv. — Powdered antimony takes fire
in chlorine gas at ordinary temperatures, and burns with a reddish white
light and emission of sparks, forming pentachloride of antimony. Ter-
chloride of antimony is never formed in this manner. (H. Hose.) —
Terchloride of antimony absorbs chlorine gas, till it is converted into the
pentachloride. (Liebig.) — The pentachloride may be prepared by passing
dry chlorine gas over powdered antimony gently heated. App, 45 may
be used for the preparation, excepting that a tubulated retort, containing
antimony and provided with a receiver, must be substituted for d. — Liebig
passes chlorine gas, dried by means of oil of vitriol, over terchloride of
antimony. — Colourless, or very pale yellow, mobile liquid, specifically
heavier than water, very volatile, fumes strongly in tne air, and has
a sharp acid odour.
Calculation. H. Rose.
Sb 129 .... 4216 40-56
5C1 177 .... 57-84 59*44
SbCl» 306 .... 100-00 100-00
Pentachlorideof antimony when heated gives off chlorine gas, together
with a small quantity of undecomposed pentachloride, and leaves a
residue of terchloride of antimony. The liquid, supersaturated with
chlorine, begins to boil at 24°; gives off the first drops of pentachloride of
antimony at 140°; and leaves a residue of terchloride of antimony at 200°:
the pentachloride of antimony which passes over may be further decom-
posed by a second distillation. (Mitscherlich.) Pentachloride of antimony
gives up chlorine to a few organic compounds— olefiant gas for example
— and is thereby converted into the terchloride. When exposed to the
air, it absorbs moisture, and is converted into a white crystalline mass of
hydrated pentachloride of antimony, or crystallized hydrochlorate of
antimonic acid; with a larger quantity of water, considerable heat is
disengaged, and the pentachloride is resolved into insoluble hydrate of
antimonic acid and aqueous hydrochloric acid, which retains only a small
quantity of antimonic acid in solution. (H. Rose.)
Hydrated Pentachloride of Antimony or Crystallized Hydrochlorate of
Antimonic Acid. — This compound forms colourless, transparent, rhombic
prisms, with dihedral summits resting on the obtuse lateral edges. Fig, 63,
without the p-face. The crystals deliquesce in the air without becoming
milky; but a larger quantity of water precipitates antimonic acid.
Solution of Acid Hydrochlorate of Antim^mic Acid,-- When hydrate of
antimonic acid is treated with hot concentrated hydrochloric acid, a
yellowish solution is obtained, which becomes cloudy after a while when
mixed with a small quantity of water, but remains perfectly clear if
treated at once with a large excess.
VOL. IV, 2,B
370 ANTIMONT.
F. Pbktaoblobidb of AvTixoirr with PaosraussRED Htuogbn.
-—When p«ntaehlori<ie of aatimonj is treated with p^osphnreited hjdiot-
gen, the gos is absorbed — a small ouantity of hydrochloric acid is evoWed
— and a red solid substance fomiea, which, with ammonia, yields sponta-
neously inflammable phosphoretted hydrogen, bat with water and other
aqneous solntiona, the non-spontaneoosly inflaanmable yariety of thai
eompound. (H. Rose, Fogg. 24, 165.)
G. Bichloride op Sulphur with Psntasulphidb op Anttmony. —
Grey salphide of antimony is not afiected by a curvent of chlorine gas at
ordinary temperatures; but if the sulphide be gently heated at one point
only, it is oompletely converted^ first into a brown liquid, and then, after
absorbing more chlorine, into a white powder. To prevent the decom-
position of the new compound by the heat evolved during the absorption
of chlorine, the tube is kept cool by moistening it with alcohol or ether.
177 parts of sulphide of antimony yield 493*2 parts of the compound; the
calculated quantity is 566*4 parts; but portions of chloride of sulphur and
chloride of antimony are volatilised by the heat, and the pentachloride
?ives off chlorine and is thereby partially converted into terchloride.
H. Rose.)
White, amorphous powder. When heated, it fuses, evolves chloride
of sulphur and free chlorine, and leaves terchloride of antimony. Dis-
solves in very dilute nitric acid, with evolution of nitrons acid fumes, but
without any separation of antimonic acid or antimonic oxide. Water
resolves it into hydrochloric acid, antimonic acid, sulphuric acid, and
hyposulphurous acid. It absorbs a quantity of ammoniacalgas, amounting
to -I of the sulphide of antimony used. (H. Rose, Pogg. 42, 532.)
Calculation.
H. Rofle.
Bb
1290 .... 22-77
25-67
S8
48-0 .... 8*48
7-6S
IICI
389-4 .... 68-75
66-70
BbCl»,3SbCP 566-4 .... 160-00 10000
The want of accordance between the analysis and the oalcoUtioa is
explained by the sources of error mentioiied in the preparatioa.
H, Tersulphidb of Antimony with Tbrchloridb of Antimont.—
By passing hydrosulphuric acid gas through acid hydrochlorate of anti-
monic oxide, a bright yellowish red precipitate is mrmed, which retains
chloride of antimony, however long it may be washed* The compound
blackens even after several hours* drying in a water bath, and evolves chlo-
ride of antimony; when heated more strongly in a retort, it gives off liquid
acid hydrochlorate of antimonic oxide, — probably from containing hygro-
scopic water, — and a small quantity of hydrosulphuric acid, leaving 90-08
percent, of tersulphide of antimony. (Gmelin.) Even when the hydro-
sulphuric acid gas is in excess, the precipitate contains terchloride of
antimony, which is evolved on heating. (Johnston, iT. Edinb, Phil, J.
18, 43.) According to H. Rose, the sulphide of antimony is precipitated
free from chloride, if tartaric acid is added to the acid hydrochlorate of
antimonic oxide before treating it with hydrosulphuric acid gas. The
precipitate thus obtained has a deeper brown-red colour, and, according to
the author's experiments, contains, after thorough washing, only a trace
of terchloride of antimony. Duflos (/Sc^tv. 67, 271) found that it still
ANTIMONY AND NITROGEN. 371
retained considerable quaDtities of tercUoride^ amounting to between
-^ and -J^ of the precipitate, according to the mode of preparation; that
onlj part could be extracted by repeated boiling with water; and moreover,
that it was not decomposed bj passing a current of hydrosulphuric acid
through water in which it was diBTusea; but, on the contrary, that bihydro-
sulphate of potash decomposed it completely, so that pure kermes was
left behind and partly dissolved.
Tersulphide of antimony dissolves abundantly in boiling hot acid
hydrochlorate of antimonic oxide, and the solution deposits yellow and
red crystals on cooling. (Liebig.)
Antimony and Fluorine.
A, Tbrfluoride op Antimony. — ^Prepared by distilling powdered
antimony with fluoride of mercury. At ordinary temperatures, solid and
snow-white; more easily volatilized than oil of vitriol, but less easily than
water. (Dumas, Ann. Ckim, Phys, 31, 435.) Crystallizes, by slow evapo-
ration from the aqueous solution, in colourless crystals. Has the taste of
tartar- emetic. Very soluble in water, in which it dissolves without the
slightest decomposition. (Berzelius, Pogg. 1, 34.)
B. and C. Tbtrafluoridb and Pentaflvoridb of Antimony. —
These compounds are very soluble in water and combine with other
metallic fluorides, forming double salts which have not been further
examined. (Berzelius.)
Antimony and Nitboobn.
A. Nitrate of Antimonic Oxide, Antimonio Nitrate.— Anti-
mony is oxidized by strong nitric acid, even at ordinary'temperatcres, but
by dilute, nitric acid only with the aid of heat; in this process, water is
likewise decomposed at the same time and nitrate of ammonia produced;
the excess of acid retains but a small quantity of antimonic oxide in
solution, and deposits small crystals [on cooling]]. The remaining oxide
combines with a certain portion of nitric acid, forming a white crystalline
powder, which is likewise obtained on treating the oxide with nitric
acid. The same salt is formed by heating antimonic oxide with nitric
acid — IT or, according to Peligot, by dissolving the oxide in cold fuming
nitric acid, and adding water to the solution, whereby it is obtained
in crystals having a mother-of-pearl lustre. H — According to Bucholz, it
contains 84f per cent, of antimonic oxide and 1 5^ of nitric acid. When
gently heated, it is converted into antimonic acid, which however is
reduced to antimonious acid by ignition. It ^ves up the whole of its
acid, even to cold water, after long continued digestion, and leaves pure
antimonic oxide. (Bucholz, Taschenh, 1 806, 89, Berzelius.) Its formula
is 2SbO^NO•. (Peligot.)
Neither antimonious acid (Berzelius) nor antimonic acid is soluble in
nitric acid. (H. Rose.)
B. Compound of Antimonio Oxide and Ammonia — Prepared by
bating oxy-chloride of antimony with solution of ammonia. White or
greyish-white granular powder, sparingly soluble in water. (Berzelius.)
2 b2
I
372 ANTIMONY.
C. Antimonitb op Ammonia. — The aqaeoas solation gives off am-
monia wheu exposed to the air and deposits a white powder consisting of
Acid AntimoniU of Ammonia. (Berzelms.)
D. Aktimoniate op Ammonia. — % a, Bihasic (I£etar)afUimonuUe, —
Obtained according to Fremy (Ann, Ckim. Fhys, 3, 23, 411), by leaving
Lydrated meta-antimonio acid (p. 331) in contact with strong solation of
ammonia for several weeks. The acid dissolves slowly, forming a salt
which is difficult of isolation, and contains 2 atoms of ammonia with
1 atom of the acid, corresponding to the bibasic potash-salt. IT
b. Mono-antimoniate, — 1. The hydrate of antimonic acid dissolves in
warm solution of ammonia; but on evaporating the solution. Acid AiUi-
mxmiaie of Ammonia is deposited, in the form of a white powder which
reddens litmus, and, when strongly heated, evolves the rest of the
ammonia together with water, leaving pure antimonic acid. (Berzelius.)
IT — 2. a. With 6 Atoms of Water (Fremy's Mono-meta-antimoniate). —
Precipitated in the crystalline form on adding a few drops of alcohol to
a solution of the bibasic salt. Very instable. [This salt forms a good
test for soda, which it precipitates almost completely.]
Calculation, a. Fremj.
NH» 17 .... 6-83
SbO« 169 .... 67-87 67-1
7H0 63 .... 25-30
NH^O,SbO* + 6Aq 249 .... 10000
^. With 4 Atoms of Water, — Fremy's Ordinary Antimoniate, — The
crystalline salt a passes into this variety spontaneously and at ordinary
temperatures in the course of a few days, even when preserved in closely
stopped bottles; the change is marked by the crystals becoming slightly
moidt and mealy, after which they are no longer soluble in water. —
2. The salt a when boiled with water loses its crystalline aspect and is
converted into a white insoluble powder, without any loss of ammonia. —
3. When either antimonic or meta-antimonic acid is dissolved in warm
solution of ammonia, this salt always separates on cooling. Moreover, if
too great an excess of ammonia is used in the preparation of a, a large
quantity of the insoluble variety appears likewise to be formed. (Fiemy.)ir
P, dried in vacuo, Fremy.
NH» 17 .... 7-3
SbO* 169 .... 73-2 740
5H0 45 .... 19-5
NH<0.8bO* + 4Aq 231 .... 1000
E. SuLPHANTiMONiATE OP Ammonittm. — A compound of Penta^
sulphide of Antimony with Hydrosulphate of Ammonia, — 1. Obtained by
digesting an excess of pentasulphide of antimony with the aqueous
solution of hydrosulphate of ammonia, and heating the mixture nearly to
the boiling point. The pentasulphide msiy likewise be digested with
ammonia, but in that case, a white powder [antimoniate of ammonia?] is
separated and the solution is less pure. The yellow solution may be
evaporated without decomposition. Acids decompose it, precipitating
the pentasulphide of antimony; it is also decomposed by alcohol, — but
then the pentasulphide contains ammonia. By decomposing the solution
with hydrochloric acid, 209 parts (1 At.) of precipitated pentasulphide of
AMMONIO-CHILORIDB OF ANTIMONY. 373
antimony are obtained to 199 parts (rather more than 3 At.) of sal-
ammoniac; — hence the solution contains 3NH^S^SbS^ (Rammelsberg,
It is moreover probable that the following compound has a similar
composition, though Kohl regarded it as consisting of hydrosulphate of
ammonia and tersnlphide of antimony. It is thus prepared: recently
precipitated and still moist tersulphide of antimony is digested in a
corerod vessel with excess of a concentrated solution of monohydro-
snlphate of ammonia, the solution filtered after cooling, and the filtrate
mixed with three times its volume of absolute alcohol. The compound is
hereby completely precipitated in the form of a white, sometimes crystal-
line, sometimes curdy precipitate, the excess of hydrosulphate of ammonia
being retained in the Hquid. In order to obtain it perfectly crystalline,
it is heated with the supernatant liquid till it dissolves — for which
purpose, the addition of a small quantity of water is often necessary, —
and then set aside to crystallize on cooling. The hydrosulphate of
ammonia must be in considerable excess, otherwise the alcohol separates
a portion of it from the compound, which then appears yellowish-red.
The crystals can only be preserved from decomposition by keeping them
under the mother-liquid in a perfectly air-tight vessel. Light yellow
rhombohedrons, having a pungent, hepatic, and nauseous metallic taste.
They contain 43'05 per cent, of hydrosulphate of ammonia and 56*95 of
sulphide of antimony. [This would lead to the formula 4NH^S,SbS',
which is not altogether probable.] When distilled, the salt evolves hydro-
sulphate of ammonia and sulphur, and leaves grey sulphide of antimony.
When exposed to the air, it evolves hydrosulphate of ammonia and turns
brown, the rapidity of the change increasing with the warmth and moisture
of the atmosphere. The salt dissolves in cold water free from air, and forms
a colourless solution; hot water, on the contrary, decomposes it imme-
diately, so that the solution cannot be evaporated without suffering
decomposition. Carbonic acid and other acids precipitate kermes from the
solution; so likewise do alcohol and ether, which extract the hydrosulphate
of ammonia. Alkaline bicarbonates precipitate the kermes after some
time only, and the monocarbonates still less readily. (Kohl, iT. £r, A rch.
17, 267.)
P. Ahmonio-terchlortdb op Antimony. — Terchloride of antimony
absorbs ammoniacal gas. (Grouvelle.) The solid terchloride absorbs the
gas but slowly; but if It be fused at a gentle heat in ammoniacal gas and
suffered to cool in it, large quantities are absorbed. The compound
when heated, gives off the whole of its ammonia, so that pure terchloride
of antimony alone remains. It does not deliquesce readily in the air,
even after long exposure. (H. Rose.)
Calculation. H. Rose.
NH« 17-0 .... 6-74 7-57
SbCP 235-2 .... 93-26 92-43
NH»,SbCP 252-2 Z. 10000 ZZ 100*00
G. Ammonio-pbntachloride of Antimony. — Pentaehloride of anti-
mony absorbs dry ammoniacal gas with considerable disengagement of
heat, and is converted into a browu substance, which turns while
when gently heated, and at a higher temperature, sublimes without
decomposition, provided it be kept out of contact of air. The sublimate
is al^o white, (H, Rose, Fojfff. ?4, 165.) Tlje element^ 9f this compouud
374 ANTIMONY.
are in such proportion, tbat, when decomposed by wter, tiM pfodttdti
are monobydrochiorate and antimoniate of ammonia. (Pereoi, Ann. CMn^
Phys, 44, 322.)
6NH»,SbCl»-^&HO = 5(NH«, HCl) + NH«,SbO«.
Calcalation. Penot.
6NH» 102 .... 25 26-05
BbCl* 306 .... 75 7S-95
6NH3,8bCl« 408 Z 100 ~. 10000
H. Compound op Tehchloribe op Antimony and Sal-ammoniac. —
A solution of 235*2 parts (1 At.^ of terchloride of antimony and 106*8
parts (2 At.) of sal-ammoniac, yields double six-sided pyramids. (Jacque-
lain, Ann. Chim, Phys, 66, 128.) — Antimonic oxide dissolves in a cold
solution of sal-ammoniac. (Brett, Phil. Mag, J. 10, 97.)
CrytialliMed.
Or:
Jt
icqvdflia
2NH<a 106-8 .... 31*23
2NH<
36
.... 10-53
8bCl» 235-2 .... 68-77
8b
.. 129
.... o7 s £ ....
37-5
5C1
.. 177
.... 51-75 ....
50-8
2NH*Cl,SbCl« 3420 .... 100-00
342
.... 10000
IT According to Poggiale (Compt rend. 20, 1180, also Ann. Pkarm.
56, 243), wben tercbloride of antimony is poured into a solation of
sal-ammoniac, a sligbt cloudiness only is produced, and tbe mixture 3rields,
on gentle evaporation, rectangular prisms composed of 3NH*Cl-f-8bCP+
3Aq. — On furtber evaporating the mother-liquid, cubes or pyramidal
cubes are deposited, the formula of which is 2NH*Cl-|-SbCl'-i-2Aq. —
Both these compounds are colourless and transparent, but become yellow
and opaque on exposure to the air; moreover, they are decomposed by a
large quantity of water. IT
Antimont and Potassium.
A. Antimonide OF Potassium. — 1. Fourparts of powdered antimony
combine readily with 1 part of potassium, the union being attended with
incandescence. (Gay-Lussac & Thenard.) — 2. The same compound, con-
taining about 5 per cent, of potassium, is formed by heating a mixture of
equal parts of antimony or roasted sulphide of antimony, and cream of
tartar, to strong redness in a covered crucible for about two hours.
(Vauquelin.) — 3. By igniting a mixture of 12 parts of antimony with
10 parts of carbonate of potash and 2 parts of charcoal. With a larger
proportion of charcoal, a black pyrophoric mass is produced. (Serullas.)
— 4. Tartar-emetic which has been first roasted in the air till it has
appeared incandescent, and then been powdered, is ignited alone,— or un-
roasted tartar-emetic is ignited with y^^ its weight of nitre. The alloy
in this case is very rich in potassium ; when unroasted tartar-emetic is
ignited by itself, it yields a black pyrophoric mass. (Serullas. )*—The
alloy must be preserved in well -dosed bottles under rock-oil. — ^Greyish*
white, soft, brittle, having a fine-grained fracture ; rather fusible. The
compound obtained by method (4) contains a larger amount of potassium;
it may be beaten out in laininA, and gives ofiT numerous sparks under the
hammer. — Oxidizes rapidly in the air, and, when in powder, disengages
ANTIMONITB OF POTASH. 376
flD maoh heftt tbat it sets fire to paper. — Under water it rapidly evolves
bydrogen gas. — When the antimony contains arsenic, the hydrogen is
mixed with arseninretted hydrogen gas. — The compound richer in potas-
sium revolves rapidly when placed on mercury moistened with water
(1., 381; Gay-Lussac & Thtnard; Vauquelin, Ann. Ckim, Fhys, 7, 32;
Serullas, J. Phyi. 91, 123.)
B. Compound op Antimonic Oxidb with Potash. — When oxy-
ehloride of antimony is digested with solution of potash, it is converted
into a greyish-white granular powder, which is hut sparingly soluble in
water; the supernatant liquid contains a small quantity of antimonic
oxide. The powder is slightly dissolved by the potash on boiling, and se-
parates again as the liquid cools (Berzelius) [in small, brilliant, colourless
and transparent crystals]. — Pure antimonic oxide yields the same com-
pound with solution of potash. After repeated washing, whereby potash
is separated, it still contains 6*35 per cent, of potash to 93*65 of anti-
monic oxide ; after this it does not give up any more potash to boiling
water, but dissolves without decomposition in 425 parts of hot water.
(Brandos, Schw, 62, 199.) — This compound dissolves less abundantly in
strong than in dilute caustic potash. The solution is rapidly converted
in the air into a solution of carbonate of potash, while antimonite of
potash crystallises out. When ignited with carbonate of potash, the
antimonic oxide expels the carbonic acid, and if in excess, forms an easily
fusible compound ; with an excess of carbonate of potash, on the contrary,
the mass is less fusible, and is resolved into metallic antimony and anti-
monite of potash. (Liebig.) — The recently precipitated oxide diissolves
abundantly in aqueous solution of potash, and in still larger proportion in
carbonate of potash; but if it be treated with a quantity of potash
smaller than that which is required for solution, a small portion only is
taken up ; after prolonged washing with water, the oxide retains only
1 per cent of potash. When antimonic oxide is fused with carbonate of
potash, and the resulting mass is exhausted with water, the antimonic
oxide which remains undissolved, retains a somewhat larger quantity,
but not in any simple stoichiometrical proportion. (H . Rose & Yarren-
trapp, Pogg. 47, 326.)
C. Antimonite op Potash. — a. Mcno-antimonite, — Prepared by fusing
antimonious acid with excess of hydrate or carbonate of potash, removing
the excess of alkali with cold water, and then treating the residue with
boiling water. The latter solution does not crystallize on evaporation,
but dries up to a yellowish saline mass, which has an alkaline and
metallic taste, and is perfectly soluble in water (very sparingly in water
containing potash). The solution, when treated with carbonic acid, even
in small quantity, deposits the salt 6.
h. ^i-an^imont^.— White powder, from which stronger acids extract
the whole of the potash. (Berzelius.)
KO
SbO*
At.
1
1
.... 47-2
.... 161-0
a. Berzelius.
.... 22-67 23-37
.... 77-33 76-63
KO,8bO*
1
.... 208-2
At.
■ •■• A ••■ ■
• «■• ^ •••■
.... 100-00 100*00
KO
SbO^
h, according to Berzelias.
47-2 .... 12-78
322-0 .... 87-22
KO,2SbO*.
1
369-2 .... 10000
376 ANTIMONY.
IT Fremy (Ann, Chim, Fhye. 3, 12, 498) denies tbd .exbtenoe of theae
salts, and regards the mass obtained by fusing thQ so'-called antimonious
acid with potash, as antinioniate of potash, mixed more or less with the
compound of antimonic oxide and potash. ^
D. Antimoniatb op Potash. — H a. BiJxuic AntimoniaU^ — ^Fremy's
NeiUral Meta-antiTnoniate. — 2KO,SbO*. When a mixtare of 1 part of
antimonic acid and 3 parts of potash is fused in a silver crucible, a mass
is obtained, which is completely soluble in water containing potash; and
the solution, on being slowly evaporated, deposits rounded crystals of thia
salt. The crystals are purified with difficulty, because water decomposes
them; they are very deliquescent. According to Fremy, the proportion be-
tween the base and the acid is (1) as 1 : 1'729; (2) as 1 : 1*63; the proportion
calculated from the formula is as 1:1 *78. Hence it may be considered
bibasic. When the salt is boiled for some time with water, and the
solution evaporated, gummy antimoniate of potash, 6, % is deposited after
a short time, and free potash found in the li^^id. But if the salt is
treated with cold water, it is resolved into f^e potash, and sparingly
soluble, granular antimoniate, or acid meta-antimoniate of potash, b, h
(E. Fremy, K Ann. Ckim. Phys, 12; 502; 23, 408.)
h. Monobasic antimoniate, — «. Monohydrate, — Obtained by exposing
the hydrate with 7 atoms of water to a temperature of 200^.
^. Terhydrdte. — Formed when the pentahydrate is heated to 160° for
several hours. Perfectly insoluble in cold water; by long continued
boiling with water, it recombines with 2 atoms of water, and is recon-
verted into the gumfuy pentahydrate. IT
7. Pentahydrate, — This salt is obtained by detonating a mixtare of
1 part of antimony or sulphide of antimony with 6 parts of nitre, and
washing the resulting mass with cold water; after this, boiling water
extracts the salt. When the solution — ^which is colourless and has a faintly
metallic but not alkaline taste, and a scarcely perceptible alkaline reac-
tion — is evaporated to the consistence of honey, it becomes covered with
a film consisting of small crystalline grains, and on cooling solidifies to a
white saline mass; if the evaporation be continued, it dries up to a
transparent fissured mass, which has a honey-yellow colour, but when
perfectly dry, appears white and opaque. The dry salt dissolves slowly
in cold but readily in hot water. From the hot solution, carbonic acid and
the stronger acids, when not added in excess, precipitate the salt c,
(Berzelias.) Hydrosulphuric acid gas passed through the aqueous
solution precipitates \ of the antimonic acid in the form of pentasul-
phide of antimony, while the compound 3KS,SbS* remains dissolved.
(Rammelsberg.)
Anhydrous. Berzelius.
KO 47-2 .... 21-83 20-8
8bO* 169-0 .... 78-17 79*2
KO,SbO* 216-2 .... 10000 ZZ 100-0
Crystalline grains, Rammelsberg.
KO 47-2 .... 18-07 17-29
SbO* 1690 .... 64-70 66-15
5H0 45-0 .... 17-23 17-17
I
•I
+ 5Aq 261-2 .... lOD'OO 100*61
^ According to Fremy, the aqueous solution above mentioned,
contains a mixture of diffcreiit salts, but chiefly the gummy and th^
ANTIMONIATB OF POTASH. 377
insoloble rariety. .The pentahydrate is soluble in water; gives pre*
cipitaies with several soluble salts, e, g,, with chloride of ammonium;
the solution dissolves the insoluble anhydrous salt with facility, and
the liquid is then precipitated by all the soluble salts, including those
of potash. .
I. With 7 Atoms of Water. — Fremy's Acid Meta-antimoniaU. — ^This
salt, according to Fremy, is the best adapted for precipitating soda, and
is prepared in the following manner : — a mixture of 1 part of antimony
and 4 parts of nitre is heated to redness in an earthen crucible, whereby
insoluble anhydrous antimoniate of potash is formed ; the mass is then
washed with cold water to separate the nitrite and nitrate of potash, and
boiled with water for two or three hours to convert it into the gummy,
soluble antimoniate, the water being replaced as it evaporates. The
mass is hereby nearly all dissolved, a small quantity only of biantimo-
niate of potash being separated. The liauid is then rendered strongly
alkaline by the addition of alcoholic solution of potash, and evaporated
till a few drops taken t>ut crystallize on cooling. The evaporation is
then stopped, whereupon the meta-antimoniate separates in abundance ;
the alkaline liquid is afterwards decanted, and the salt dried on plates of
baked porcelain. The salt invariably contains an excess of alkah ; hence
it should always be washed two or three times with water before use;
and since it is decomposed by long contact with water — first passing
into the gummy variety, and then depositing insoluble bi-antimoniate — it
should be preserved in the dry state, and dissolved just before use. This
salt is characterized by giving an instantaneous crystalline precipitate
with salts of soda, and not affecting the dilute solution of an ammoniacal
salt. (Fremy.) IT
Fremy.
■■
KG 47-2 .... 16-91
8bO» 1690 .... 60-53
7H0 630 .... 22-56
(1)
(2)
21-6 .... 22-0
KO,SbO*+7Aq. 2792 .... 10000 99-2 .... lOO'O
c. Bi-antimoniate, — Antimonium diaphoreticum ahltUum, Cerussa Anii-
monii, Calx Antimonii alba, — 1. Prepared by mixing antimony or sulphide
of antimony with excess of nitre, and projecting the mixture into a red hot
crucible by small portions at a time ; igniting the mass for some time
after the detonation has ceased; and then exhausting with water, which
removes nitrate, nitrite, and mono-antimoniate of potash (and likewise
sulphate, when sulphide of antimony has been used, and arseniale of
potash if any arsenic were present), and leaves the salt h, — As thus
obtained, it is contaminated with the oxides of lead, iron, and copper,
when these metals are present in the antimony used; and also with a
quantity of the compound of antimonic oxide and potash, (separable by
acetic acid), the amount of which is greater, the smaller the proportion of
nitre in the mixture, and the shorter the time of ignition. (0. Figuier.)-—
2. A mixture of 1 part of antimony purified by Liebig's method (p. 320)
with 3 parts of nitre is detonated; the crucible kept at a red heat for an
hour and a half ; the mass when cold reduced to powder and diffused in
4 parts of water; the clear liquid decanted; the residue boiled with
3 or 4 parts of water; the insoluble portion, which consists of impure
salt &, washed with boiling water; and the resulting solutions, which
contain tb^ QaU a^ trea^d with a current of carbonic acid gas : an
378 ANTIMONY.
additional qoantitj of the salt b is then obtained, petfectly pure and vkite.
(0. Figuier, /. Pkarm. 25, 92 ; also Ann, Pkarm. ZO, 238.) — Instead of
carbonic acid, acetic acid may be nsed, the acid being added in saeh
quantity that the solution may still have a feebly alkaline reaccioa
(Bachner); with the slightest excess of acetic acid, the antimonic acid
is precipitated nearly free from potaeli. (Fignier.) — ^The preparation of
the Fkarm. Bor. — which recommends boiling the mass obtained by
igniting the rairtare of antimony and nitre with water and excess of
salphnric acid — ^is merely hydrate of antimonic acid. — ^Moreover, by
boiling antimonic acid to dryness with a large excess of solution of potas^
and igniting, a mass is obtained which leaves a raiall qoantity of bi-anti-
moniate of potash undissolved, on treating it with boiling water. (Buchner,
Repert, 66, 168.) When antimonic acid is bmled with solution of potacAi,
it combines with a portion of the potash, but does not dissolve com*
pletely, even with a large excess of potash and water. (H. Rose,
Anal, Okem.) — ^White powder.
Tffmfed, Bendins.
KO 47-2 .... 12-26 102
28bO» 338-0 .... 87-74 89*8
KO,28bO» .... 385-2 .... 100-00 ZZ 1000
UniffnUed, Guibomt.
KO 47-2 .... 10-76 10-97
2SbO» 338-0 .... 76-96 7673
6H0 540 .... 12-29 12-30
+ 6Aq 439-2 .... 10000 ~. 10000
E. SuLPnANTiMONiTB OF PoTAssiUM. — Liver of Antimony y Hepar
Antimonii, — Protosulphide of potassium may be fused in all propor-
tions with tersulphide of antimony. These compounds may be obtained
by igniting sesquisulphide of antimony with sulphate of potash and
charcoal, or with carbonate'of potash and charcoal — e.g., the slag formed in
the preparation of antimony with black J9ux (p. 318, 2), — or simply with
carbonate of potash, whereby the compound of antimonic oxide and
potash (or if the sulphide of antimony predominates, oxy-sulphide of
antimony,) is produced at the same time. ( Vid, p. 375.)
a, A mixture of 177 parts (1 At.) of grey sulphide of antimony,
with 485 parts (about 9 At.) of protosulphide of potassium, yields by
fusion, a liver of antimony, which, after being poured out of the crucible^
flies in pieces on cooling ; it also yields a greyish-yellow powder. (KohL)
6. By treating sulphide of antimony with excess of carbonate of
potash, a compound of 1 atom of tersulphide of antimony with 2 atoms
of protosulphide of potassium is formed^ besides the compound of anti*
monic oxide and potash. (Berzelins.)
7(K0, CO*) + 5SbS» = 3(2KS. 6bS») + KO, 2SbO» + 7C0«.
c. By fusing 3 parts of carbonate of potash with 8 parts of sulphide
of antimony, a compound is produced, containing 1 atom of tersulphide
of antimony with 1 atom of protosulphide of potassium, having the form
of a liver-brown, easily fusible mass. (Berzelins.)
7(K0, C02) + SSbS^ = 6(KS, SbS') + KO, 2SbO» + 7C0«.
d. One part of carbonate of potash yields with 16 parts of sulphide
of antimony a steel-grey, brittle mass, having a conchoidal, non-crystal-
line^ metallic-shining fracture, and yielding a dark-brown powder. (Ber-
SULPHANTIMONITB OF POTASSIUM. 379
zelins.)— In this case, besides Regulu9 antimanii medieinalis (p. S59\
there is also fonned a compound of sulphide of potassium with a large
excess of sulphide of antimony.
All livers of antimony are brown, fuse easily, and when poured on a
flat surface, contract strongly, decrepitating and flying asunder as they
cool, (Vid. Marx, Sehw, 59, 251.)— When they are strongly ignited out of
contact of ur, metallic antimony is separated, and the lirer of antimony
is partly oonrerted into a compound of protosulphide of potassium with
pentasulphide of antimony,*so that, on dissolriuff the mass in water and
treating it with an acid, kermes is precipitated at first, and then the
lighter>coloured pentasulphide of antimony. (H. Rose.) — When ignited
in the air, they bum with formation of white fumes. They colour the
skin brown (from containing crociu antitnonn\ rapidly attract moisture
from the air, and are resolved by water into soluble sulphide of potassium
(which then dissolves a portion of the sulphide of antimony), and an
insoluble residue of sulphide of antimony, mixed either with oxy-sulphide
of antimony, or the compound of antimonic oxide and potash. According
to Kohl, tne compound a, which is rich in sulphide of potassium, is the
only variety which dissolves almost completely.
Solution of Sulphantimanite of PotasHum, or Hydrotulphate of
Antimonic Oxide and Potash, — 1. Obtained by dissolving liver of anti-
mony in water. — 2. By dissolving sulphide of antimony or antimonic oxide
in solution of hydrosulphate of potash. — If bibydrosulphate of potash is
used, hydrosulphuric acid gas is evolyed; 1 At. of the hydrosulphate
does not dissolve so much as ^ At. of sulphide of antimony. (Berzelius.)
By saturating a hot aqueous solution of hydrosulphate of potash with
kermes, a compound of 177 parts (1 At.) of sulphide of antimony with
485 parts (9 At.) of protosulphide of potassium remains dissolved after
cooling. (Kohl.) — 3. oy dissolviuj^ sulphide of antimony in boiling solu-
tion of potash. The compound of antimonic oxide and potash is hereby
formed at the same time. (p. 875.) — The more concentrated and the
hotter the alkaline solution, the greater is the quantity of sulphide of
antimony dissolved; and on diluting or cooling the liquid, a- portion of
the sulphide is precipitated, and sometimes forms a gelatinous mass. An
excess of free potash, however, prevents the precipitation on cooling.
(Berzelius.) — The solution when exposed to the air, deposits kermes, and
is partially converted into a solution of sulphantimoniate of potassium.
(Berzelius.) TThe deposition of kermes is caused by the carbonic acid
in the air; tne formation of the sulphantimoniate of potassium arises
from a portion of the potassium being oxidized by the air, and the
sulphur, hitherto combined with it, passing over to the tersulphide of
antimony.]
When the slightly yellow solution of the liver of antimony (a) in
water, or of kermes in aqueous sulphide of potassium, is evaporated to a
syrupy consistence, it yields colourless and transparent rhombic laminse^.
and flattened needles, arranged in stellated masses, which may be dried by
exposure to gentle heat in a vessel containing chloride of calcium. The
crystals have a nauseous, bitter, alkaline, and hepatic taste; when strongly
heated they lose water, and become opaque, and are converted into
brown liver of antimony, which redissolves in water, merely producing
a slight turbidity in the liquid. — They dissolve in hydrochloric acid,
forming a nearly transparent liquid. With water, they yield a colourless
solution, which is decomposed by acids including the carbonic, and also
by bicarbonate of ammonia^ potash, or soda, hydrosulphuric acid being
380 ANTIMONY*
aetfree^ and yellowish-red salpbide of antimony precipitated ; monoear-
bonate of potash or soda, on Uie contrary, produces a precipitate of the
colour of kermes. Even by exposure to the air, amorphous sulphide of
antimony is precipitated. By boiling the solution with an additional
Quantity of kermes, so large a portion is taken up, that the liquid soli-
aifies in a brown magma on cooling. Absolute alcohol does not dissolve
the crystals, but precipitates a portion of the salt in oily drops from the
aqueous solution ; hydrated alcohol dissolves a quantity proportional to
the amount of water which it contains. (Kofll, iv. Br, Arch. 17, 259.)-^
It yet remains to be determined whether these crystals are not hydrated
sulphantimoniate of potassium.
P. Sulphantimoniate op Potassium. — This compound is likewise
a kind of Liver of Ardinumy. — 1. It is prepared by a method similar to
that used in the preparation of sulphantimonite of potassium, but with
the addition of a sufficient quantity of sulphur, previous to fusion. —
2. By fusing tersulphide of antimony with a mixture of bisulphate of
potash and charcoal. — 3. Or by fusing the same compound with tersul-
phide, tetrasulphide, or pentasulphide of potassium. — 4. By exposing
sulphantimonite of potassium to a strong red heat, whereby antimony is
reduced. — Resembles the preceding compound in its physical properties
and chemical relations ; but its aqueous solution does not deposit penta-
sulphide of antimony, but only the tersulphide that may happen still to
be mixed with it.
Hydrated SulpharUimoniaU of Potassium or Hydrosulphate of Anti-
monic Acid and Potash. — 1, Prepared by boiling a mixture of 11 parts
of purified grey sulphide of antimony with 6 parts of carbonate of pot-
ash, 1 part of flowers of sulphur, 3 parts of burnt but afterwards
slaked lime, and 20 parts of water, for two hours, — or by leaving the
mixture at ordinary temperatures in a covered vessel for 24 hours, stirring
frequently, then filtering, washing the residue, evaporating the filtrate,
and, lastly, setting it aside to cool. (Liebig, Handworterh. 1, 434.) —
2. By fusmg a mixture of bisulphate of potash, grey sulphide of anti-
mony and charcoal, as in the preparation of the pure i)entasulphide,
(p. 355, /3) then boiling the powdered mass with water and sulphur, and
evaporating the filtrate to a thin syrupy consistence. (Geiger, Mag.
PJuirm, 29, 236.) — 3. By fusing a mixture of nionosulphate of potash,
grey sulphide of antimony, charcoal, and sulphur, dissolving the resulting
mass in water, and filtering the liquid. The product thus obtained is
less than by method (1). (Rammelsberg.) — 4. By boiling sulphantimonite
of potassium with water and sulphur. The solution when sufficiently
evaporated, yields, on standing, colourless granular, deliquescent crystals ;
but if the evaporation be carried too far, a radiated mass is obtained.
(Geiger.) The crystals are yellowish, and fuse when heated, giving oflT
water and leaving a brown mass. They deliquesce rapidly in the air^
and^become covered with kermes. (Rammelsberg.)
Crystallized. Rammelsberg.
3KS 165-6 .... 36-35 36*679
SbS* 209-0 .... 45-87 45*167
9HO 81-0 .... 17*78 18-154
3K8,Sb8« + 9Aq. 455*6 .... 10000 IZl 100-000
When pentasulphide of antimony is dissolved in moderately strong
solution of potash, and after dilution with water, precipitated by carbonate
pf ammonia or bicarbonate of potash; a kcrmes-coloured precipitate is
CHLORIDE OF ANTIMONY AND POTASSIUM. 381
fonnecl, which, after prolonged washing and drying at 100^, contains
potassium 3*06, antimony 55*40, and sulphur 80*45 (loss 2*09) per cent.
(Rammelsberg.) This nearly corresponds to KS,6SbS^ but the analysis
gives rather too much sulphur.
G. Compound of Sulphantihoniatb of Potassium with Anti«
MONiATB OF PoVash. — Pentasulphide of antimony dissolves in mode-'
rately concentrated solation of potash, with separation of a heavy white
powder, consisting of bi-afltimoniate of potash j the filtrate yields, on
evaporation, long colourless needles, which, when exposed to the air, do
not deliquesce, but acquire a brown coating. This salt is likewise pro-
duced by boiling tersulphide of antimony with sulphur, carbonate of
potash, lime, and water. At a temperature a little above 100"^, the salt
loses its water of crystallization, turns yellow, and fuses to a reddish-
brown mass, which becomes orange-yellow when cold. Acids precipitate
from it a mixture of pentasulphide of antimony and antimonic acid or
bi-antimoniate of potash, a small quantity of hydrosulphuric acid gas
being at the same time evolved. Cold water dissolves it but partially,
leaving a white powder of mono-antimoniate of potash ; boiling water,
on the contrary, dissolves it completely. If the antimonic acid be sepa-
rated from the latter solution by chloride of barium, the filtrate evolves
hydrosulphuric acid gas on the addition of acids, and gives a precipitate
of pure pentasulphide of antimony. (Rammelsberg.)
4K
Crysialliied.
156-8 .... 23-03
2580 .... 37-90
1280 .... 18-80
480 .... 705
90-0 .... 13-22
Rammelsberg
22'6(f
28b
37-80
88
60
lOHO
18-20
Z 13-30
3KS,SbS* + KO,8bO» +
Or:
3KS ...•
SbS* ....
KO
SbO» ....
lOHO....
lOAq.
680-8
165-6
209
47-2
169-0
90-0
• •■•
• •••
100-00
24-32
30-70
6-93
24-83
13-22
680-8
• •••
.... 10000
H. Chloride of Antimony and Potassium. — a. With 2 Atoms
of Chloride of Potoinum, — The aqueous solution of a mixture of 2 atoms
of chloride of potassium and 1 atom of terchloride of antimony, yields
oblique rhombic prisms. (Jacquelain, Ann. Chim, Pkys, 66, 128.)
Calculation. Jacqaelain. Or :
2K 78-4 .... 20-39 .... 20-2 2KC1 149-2 .... 38-81
Sb 129-0 .... 33-56 .... 328 8bCl» .... 235-2 .... 6119
5Cl 177-0 .... 4605 .... 46-3
2KCl,Sba» .... 384-4 .... 10000 Z 99^ 3844 .... 10000
IT 6. With 3 Atoms of Chloride oj Po^amim.— SKCl + SbCR-
Crystallizes in laminse. Deliquescent; decomposed by boiling water.
(Poggiale, Compt, rend. 20, 1180.) IT
kV
388 ANTIMONT.
AMTDfOirT AJfD SOBIVV.
A. Antimonibb of Sodium. — a. Four {Murts of powd«red aaiiHionj
combine with one part of sod i am at a temperature just above the melting
point of antimonjy the aet of eombinatioK being attended with incan-
desoenoe. — Verj brittle alloy, resembling bell-metal in its firactaze,
lapidlj decomposed in the air, and effervescing strongly with water and
aqueous acids. (Oay-Lussao & Th^nard.) *
b. When antimony is strongly ignited with an eqval weight of
tartrate of soda in a covered orudble for some hours, the result is a greyish
black mass, which takes fire in the air and is decomposed by water. A
mixture of antimony and soap, or of 8 parts of antimony with 4 partn ef
carbonate of soda and 1 part of charcoal, likewise yields a similar alloy.
(Serullas.)
B. Compound of Antihonig Oxidb and Soda. — ^When 1 atom of
antimonic oxide is fused with excess of carbonate of soda, 1 atom
of carbonic acid is expelled: consequently the resulting compound is
NaO,SbO'. (Mitscherlich.) The greater part of the soda is extracted by
water. (Mitscherlich, H. Rose.) A solution of antimonic oxide in soluUon
of soda, after exposure to the air for some time, deposits eryataAs of
antimoniate [antimonite f] of soda. (Mitscherlich.)
C. Antimonite of Soda. — Soluble in water. (Berzelius.)
D. Antimoniate of Soda. — IT a. Monohydraie. — Fremy's Acid
Meta-arUimoniate. — NaO,HO,SbO'. — Obtained by heating the salt h to
between 180° and 200°. If — 6. WUh 7 cAofM of tra^^-.— When an
aqueous solution of antimoniate of soda is supersaturated with caustic soda,
this salt often separates in short, tabular, perpendicularly truncated square
prisms. If the liquid also contains the compound of antimonic oxide and
soda, that compound remains dissolved. (Mitscherlich.)-— 5. Antimoniate
of soda is nearly insoluble in water. Hence a solution of antimoniate of
potash added to a soda-salt gives, after some time, a crystalline antimo-
niate of soda free from potash. The solution of 1 part of a soda-salt in
350 parts of water is still precipitated in this manner, and even when
the solution contains 100 parts of carbonate of potash to 1 part of
carbonate of soda; but in a larger excess of carbonate of potash, the
antimoniate of soda is slightly soluble. (Fremy, Compt. rend, 16, 187;
also N", J. Fharm. 3, 97; also J", pr. Ckem. 29, 86.) Antimoniate of
soda is but very sparingly soluble in boiling water, and separates from the
solution, on cooling, in brilliant, colourless, and transparent crystalline
grains. (Gmelin.)
IT According to Fremy, salts of soda are precipitated slowly, and
frequently in rather large crystals, by the gummy pentahydrated anti-
moniate of potash, and immediately dv the acid meta-antimoniate. In
the former case, however, the antimoniate of soda is always more or less
mixed with the flocculent precipitate which the insoluble antimoniate of
potash gives with soluble salts. In testing for soda in organic salts, it
is necessary first to convert them into carbonates, chlorides, or sulphates,
— because antimoniate of potash often gives a flocculent precipitate
with organic salts of potash after standing. The addition of alcohol
i
SULPHANTMOMITS OF SODIUM. 383
lenden tira preeipxtation of ihe aniimoiiiate of soda oompletey but it is
necesaaiy to waak afterwards with water, to remoYO the other ttlts
which are thrown down at the same time.
Calcotatioii. Tremj.
NaO 31-2 .... U*M 12-0
8bO» 1690 .... 64-21 ., 64-3
7HO 63-0 .... 23-93 240
NaO,SbO*+7Aq 263*2 .... 10000 100-3 f
Before the blowpipe, either of the three oxides of antimoB j giree with
mtHfonate qf $oda, a ghaa which is transparent and oolonrlesis while hot,
but white and opaque when cold. (Berxelins.)
E. Borax dissolyes a lar^e quantity of antimonioua acid before the
blowpipe, forming a glass which is transparent and yellow while hot, but
which, if it contains a large excess of antimonious acid, becomes grey in
the inner flame, from reduction of antimony. (Berzelius.)
F. Microcotmie salt likewise dissolves antimonious acid, producing a
dear colourless glass, which in the outer flame appears yellowish when
hot» and turns red if ferric oxide be present. (Berzelius.)
G. SuLPHANTiMONiTB OF SoDiUM. — Also a Liver of Antimony, —
a. A mixture of 177 parts (1 At.) of grey sulphide of antimony with
355 parts (9 At.) of monosulphide of sodium and between 15 and 17
parts of metallic antimony yields, by fusion at a gentle heat, a liyer-
coloured mass. (Kohl.) — 6. A mixture of 15 parts of sulphide of antimony
with 10 parts of fused Glauber's salt, exposed to a white heat in a
coyered charcoal crucible, yields, besides 0*5 metallic antimony, only
17 parts (because a portion of the compound volatilizes) of a radish--
brown dense mass, destitute of metallic lustre, but having a brilliant
fracture. This substance deliquesces in the air, and is resolved by
boUing water into insoluble kermes and a brown solution. (Berth ier.)
SolrUion of Sulphantimonite of Sodium or HydrotulphaU ofAntimonic
Oxide and Soda, — 177 parts of precipitated tersulphide of antimony
require for solution 355 parts of aqueous sulphide of sodium. The
solution is prepared by boiling ; but with these proportions, no sulphide of
antimony separates on cooling. (Kohl.) The solution gives a brownish-
red preoipitate with monocarbonate of potash or soda. (H. Rose.) A
solution of tersulphide of antimony in boiling carbonate of soda deposits^
after long exposure to the air, crystals of antimoniate of soda contaminated
with kermes. ^Mitscherlich.)
The crystals which are deposited from solutions of this kind, appear
to consist of hydrated sulphantimoniate of sodium (Schlippe's salt), and not
of hydrated sulphantimonite of sodium. Pagenstecher (^epert» 14, 112)
ignited a mixture of 2 parts of grey sulphide of antimony with 4 parts of
dry sulphate of soda and 1 part ot charcoal ; dissolved the resulting mass
in 15 parts of boiling water; and obtained crystals by cooling or on
the addition of alcohol. These colourless and transparent crystals,
however, did not yield any kermes on the addition of acids, but only the
golden sulphide; and their aqueous solution could not be made to take up
an additional quantity of sulphur. Kohl {N, Br, Arch, 17, 263) dissolved
the liver of antimony— obtained by fusing together at a gentle heat,
177 parts of tersulphide of antimony, 17 parts of metallio antiiponyj and
384 AMTEMONT.
B55 parts of protogulphide of sodiam in the smallest possible quantity of
boiling water, at the same time adding powdered antimony, and left the
filtrate to c^stallize on cooling. Or^ agftin? he boiled a mixture of
177 parts of tersulphide of antimony, prepared in the wet way, with
355 parts of protosolphide of sodium, water, and a small quantity of
powdered antimony. By these means he obtained pale yellow, regular
tetrahedrons, containing 20'9 per cent of protosulphide of sodium,
44*4 of tersulphide of antimony, and 34*7 of water. These crystals, when
heated, lost water and left a yellowish-brown residue. They dissolved
ia hot concentrated hydrochloric acid, with the exception of a trace of
sulphur. Their aqueous solution took up a large quantity of kermes at
the boiling point, and again deposited it on cooling. When exposed to
the air, it deposited kermes spontaneously; with acids, including the
carbonic, and with alkaline bicarbonates, it immediately gave a preei*
pitate of sulphide of antimony; and with monocarbonate of potash or
soda, after some time, a precipitate having the colour of kermes, &c.
Kohl himself, however, suspected that this salt contained a portion of
Schlippe's salt mixed with it : according to Kircher's experiments, (Ann,
Pkarm, 31, 341) it consists almost entirely of that salt. Kircher
obtained these tetrahedrons by boiling 2 part« of hydrated octohedral
protosulphide of sodium (III., 9G) with a small quantity of powdered
antimony out of contact of air, and afterwards with 1 part of tersul-
phide of antimony, prepared in the wet way, till the whole was dis-
solved (whereby metallic antimony was separated, the quantity in-
creasing considerably on cooling), and lastly covering the filtrate with a
stratum of alcohol. The resulting crystals contained 23*60 per cent, of
protosulphide of sodium, 41*50 of sulphide of antimony, and 35*18 of
water; the sulphide of antimony, however, on being ignited in hydrogen
gas, yielded metallic antimony corresponding in quantity to 25*5 per cent,
in the crystals; whence it follows that the salt contained pentasulphide
of antimony with a very small quantity only of the tersulphide. In other
respects, the compound exhibited the properties mentioned by Kohl, and,
like his salt, dissolved in hot concentrated hydrochloric acid, with sepa-
ration of a small quantity of sulphur.
Another salt prepared by Kohl was probably more free from Schlippe^s
salt : the mode of preparation consisted in heating the mixture of 177 parts
of sulphide of antimony and 354 parts of sulphide of sodium at a higher
temperature — till in fact the fused mass became red hot — ^and then
treating it, as above, with water, keeping it as much as possible from
contact of air. The crystals thus obtained formed colourless and transpa-
rent prisms arranged in stellated groups, and contained 34 per cent, of
sulphide of sodium, 25 of sulphide of antimony, and 41 of water.
Moreover, they dissolved in hydrochloric acid with scarcely perceptible
cloudiness, deliquesced in the air, and in other respects exhibited nearly
the same properties as the tetrahedral salt.
H. SuLPHANTiMONiATE OP SoDiUM. — HydraJUd. — Schlippe's Salt —
1 . Prepared by fusing 4 parts of grey sulphide of antimony with 8 parts
of dry sulphate of soda and 2 parts of charcoal — boiling the mass, when
cold, with water and 1 part of sulphur — ^and lastly filtering and setting
aside to crystallize. Nine parts of crystals are hereby obtained; and the
mother-liquid retains scarcely a trace of antimony, since it gives with
acids a precipitate of nearly pure sulphur. (Schlippe, Schto. 33, 320.)
During the fusion^ a large quantity of metallic antimony separates^ in
SULPHANTIMONIATB OP SODIUM. 385
consequence of the formation of pentasulphide of antimony; and the mother-
liquid retains a considerable quantity of caustic soda : consequently, only
the acid of part of the Glauber's salt is decomposed by the fusion, and the
sulphur of that salt combines with the tersulphide of antimony, while the
soda is set free; the latter is then converted, by boiling with sulphur, into
pentasulphide of sodium and hyposulphite of soda, and does not further
contribute to the formation of Scnlippe's salt. If sulphur is added to the
other ingredients, it volatilizes so quickly during the fusion that it does
not assist in the formation of the compound. (Duflos, Br, Arch, 31, 94.) —
2. A mixture of 24 parts of dry sulphate of soda with 4 parts of charcoal
powder is ignited till the frothing ceases ; the mass^ after being poured
out and cooled, is then boiled for half an hour with 6 times its weight of
water, 18 parts of grey sulphide of antimony, and 3 parts of sulphur, and
the liquid filtered and, left to crystallize. 36 parts of crystals are thus
obtained. By similarly treating a mixture of 8 parts of sulphate of soda,
2\ parts of charcoal, 1 part of sulphur, and 6 parts of sulphide of
antimony, 12 parts of crystals are produced. The mother-liquid contains
hyposulphite of soda. (Duflos.) — 3. An intimate mixture of 24 parts of
grey sulphide of antimony, 24 parts of dry carbonate of soda, 14 parts of
sulphur, and 3 parts of charcoal, is ignited in a covered crucible — the
resulting mass, when cold, dissolved in water — and the solution filtered.
{Pkarmac, Bonus.) The greater part of the sulphur volatilizes before fusion
commences; consequently, 8 parts of metallic antimony are separated.
On treating the mass with water, a large quantity of crocus antimonii
remains undissolved, and the product of crystals amounts to only 6 parts.
(Duflos.) F. C. Bncholz (Br. Arch, 33, 1) obtained by this process
10 parts of crystals, and by boiling the solution with sulphur, 12 parts.
The fusion should be continued till the mass no longer swells up much ;
for if it be sooner stopped, carbonate and sulphate of soda — the latter
produced at the commencement by the action ot sulphur on the carbonate
of soda— remain undecomposed; and if the fusion be prolonged till the
mass ceases altogether to evolve carbonic oxide, it dves off sulphur and
becomes oxidized, and when subsequently dissolved in water, yields a
large quantity of kermes and fewer crystals. (Jahn, N. Br. Arch. 22, 43.)
— 4. A mixture of 72 parts of elutriated grey sulphide of antimony, 13 parts
of flowers of sulphur, 48 parts of dry carbonate of soda, and 52 parts of
burnt lime, is boiled with water in an iron vessel for 2 or 3 hours, then
filtered, and evaporated to the crystallizing point. (Mitscherlich.) Or a
mixture of 9 parts of sulphide of antimony, 3 parts of flowers of sulphur,
18 parts of crystallized carbonate of soda, 5 parts of lime previously
slaked with 5 parts of water, and 80 parts of water, is treated precisely in
the same manner. By decanting the mother-liquid from the crystals, and
boiling a second time with the residue, a further crop of crystals is
obtained. The total quantity of crystals amounts to 15 parts. (Frederking,
N, Br, Arch. 28, 64.) Or again, a mixture of 11 parts of sulphide
of antimony, 1 part of flowers of sulphur, 13 parts of crystallized carbonate
of soda, and 5 parts of burnt lime previously slaked with 20 parts of water
may be used. The same ingredients may likewise be left in a closed
vessel for 24 hours at ordinary temperatures, the whole being frequently
shaken. (Liebig, Handworterh, 1, 433.) — 5. A solution of soda liver
of sulphur is saturated with sulphide of antimony and sulphur at a
boiling heat, and the liquid filtered. (Liebig.) The salt likewise crys-
tallizes from a solution of pentasulphide of antimony in caustic soda,
and from liquid soap of antimony. (Schlippe.) A small quantity of
TOL. IV. 2 c
386 ANTIMONY.
caiutio 8oda must be added during the eTaporation, to prevent the
precipitation of kermes, whereby the crystals would be rendered impure.
(Pfaff.)
? 6. Jaiissen {J, pr, Chem. SB, 336) projects an intimate mixture of
4 parts (3 At.) of crystallized sulphate of soda, 3^ parts (1 At) of
tersulphide ot antimony, and 1 part of charcoal into a red-hot crucible,
and ignites the mixture out of contact of air till it fuses tranquilly; be
then adds \ pt. (2 At) of sulphur, stirs well, and pours the whole out.
The fusion must not be continued too long, otherwise tbe tersulphide of
antimony will be converted into antimonic oxide, and then reduced by
the charcoal. The liver of antimony thus obtained is exhausted with
water (to which, when crude sulphide of antimony has been used, a small
Quantity of caustic soda is added to precipitate oxide of iron), and the
nitrate evaporated to the crystallizing point. It may likewise, according
to Janssen, be obtained in the wet way, by gradually adding tersulphide
of antimony to a boiling solution of pentasulphide of sodium, and then
mixing the liquid with caustic soda, till the sulphur, which at first
separates in large quantity, is nearly redissolved — ^then again adding
tersulphide of antimony— and so on. The pentasulphide of sodium should
remain in excess, which may easily be known by dropping the liquid into
solution of hydrosulphuric acid, when a white cloud is formed if any of
the salt is still present. The solution is lastly filtered and evaporated,
whereupon crystals of the pure salt are deposited.
7. A mixture of 8 parts of effloresced sulphate of soda, 6 parts of
sulphide of antimony, and 3 parts of charcoal, is projected into a red-hot
hessian crucible; the cover put on ; the mixture neated till it ceases to
froth up, and then boiled with 1 part of sulphur and a sufficient quantity
of water. The solution, soon after cooling, deposits colourless or pale
yellow tetrahedrons, which are insoluble in alcohol, but dissolve in
3 parts of cold water. (Van den Corput, Chem. Gazette, 1848, 268.) %
The crystals, obtained by either of these processes, are washed with a
small quantity of cold water; dried, first between blotting-paper and then
under a receiver beside oil of vitriol; and lastly preserved in well-stopped
bottles.
Pale yellow, almost colourless, transparent regular tetrahedrons,
having either the terminal edges replaced by planes (Fig. 14), or
acuminated with 3 faces (those of the rhombic-dodecahedron) restins on
the faces of the tetrahedron. Sometimes also the ed^es of the tetrahedron
are replaced by six-sided summits, corresponding to those of the pyramidal
cube. (Fig. 9.) (Rammelsberg.) The crystals have a bitter alkaline and
metallic taste. When pure, they remain colourless in the air, and if
kept dry, undergo very little change ; but when they contain the com-
pound of antimonic oxide and soda, they rapidly change colour in the air.
(Janssen.)
Crjfitailized. Rammelsberg. Schlippe. Doflos.
3NaS 117-6 .... 24-07 .... 24-36 .... 2417 .... 2176
SbS» 2090 .... 42-77 .... 42-29 .... 41-72 ... 5675
18HO 162-0 .... 33-16 3335 .... 3403 .... 20SO
3NaS,Sb8» + 18Aq 4886 .... 10000 .... 10000 .... 99-92 .... 9901
The crystallized salt loses 20*5 per cent, of water when pulverized and
dried in vacuo over oil of vitriol. (Du6os.^ When heated out of contact
of air, it melts in its own water of crystallisation, after the expulsion of
which there remains a greyish*white mass; this, when exposed to the air,
SULPHANTIMONIATE OF SODIUM. 387
cramUes to a bulky powder ; or if stronglj heated out of contact of air,
fuses to a lirer-coloured mass, which^ on being dissolved in water^ leaves
but a small residue of sulphide of antimony. (Rammelsberg.) When
ignited in a current of hydrogen gas, it gives off its water of crystallization,
but no sulphur. (H. Rose.) When heated on the open fire, it effloresces,
rapidly turns red, and then black, burning with a sulphurous flame and
leaving a white mass. (Schlippe.) When a concentrated solution of the
salt is exposed to the air, it deposits pentasulphide of antimony in the
form of a granular powder; and hyposulphite of soda is formed in it; a
dilute solution on the contraiy, deposits white crystalline flakes of
bi-antimoniate of soda. (Liebig, Ann. Fharm. 1, 13.) This decomposition
is efiected by the carbonic acid in the air; for when air freed from
carbonic acid is passed through the [concentrated?] solution, no change is
produced. A solution which has been perfectly decomposed by many
months' exposure to the air, contains carbonate and hyposulphite (no
sulphate) of soda; and the dark reddish brown precipitate, which colours
the wash-water yellow and becomes lighter, contains, after washing,
1*94 per cent, of sodium, 66'39 of antimony, and 30*11 of sulphur
(loss 1-56). This percentage gives lNa,6Sb,23S=NaS,2SbS^4SbS^
hence the pentasulphide must lose a portion of its sulphur, which then
serves for the formation of the hyposulphite of soda. (Rammelsberg.)
The fact of the imperfectly dried crystals becoming brown in the air
likewise depends on this decomposition. All acids, including even
carbonic acid, decompose the solution, precipitating pentasulphide of
antimony and liberating hydrosulphurio acid :
3NaS, SbS* + 3SO» + 3H0 = 3(NaO, S0>) + SbS» + 3HS.
By boiling with excess of hydrochloric acid, the pentasulphide of antimony
is dissolved, with separation of sulphur. Carbonic acid gas passed
through the solution, precipitates only the greater part of the pentasul-
phide; but if the filtrate, which is only slightly clouded by carbonic acid gas,
be freed by boiling from the hydrosulphurio acid accumulated in it, the
remainder of the pentasulphide of antimony is precipitated on treating it
with a fresh current of carbonic acid gas. (Gmelin.) Alkaline mono-
carbonates do not throw down a brownish-red precipitate from the solution
of this salt, as they do from a solution of sulphantimonite of sodium.
(H. Rose.) On mixing a solution of tartar-emetic with a solution of
Schlippe's salt, an orauj^coloured precipitate is produced. This precipi-
tate contains 2Sb,4S,30, which may be reduced to the formula: SbO^SbS^
or 2SbO^SbS^SbS^ Of the 3 atoms of SbO^ contained in 3 atoms of
tartar-emetic, 2 atoms remain undecomposed ; the third SbO' reacts
upon 3NaS, forming SbS' and 3NaO. (Rammelsberg.) By boiling a
solution #f the salt with sulphur for several hours, it is entirely decom-
posed, a kermes-coloured powder being precipitated. (Gmelin.) The
aqueous solution at its boiling point dissolves antimonic oxide, and
on cooling deposits a grey compound, which contains 30*5 per cent, of
antimonic oxide and 69*5 of kermes; when an excess of antimonic oxide is
used, the above precipitate is accompanied by crystalline grains of the
compound of antimonic oxide and sodft. (Dnflos.) By boiling the solution
with powdered antimony, the sulphantimoniate of sodium is converted
into sulphantimonite of sodium, which deposits a large quantity of
kermes on cooling, still more on the addition of common salt, and the
remaining portion on the addition of an acid (p. 348). (Duflos.) The
solution dissolves grey sulphide of antimony when boiled with it, and, on
2c2
388 ANflMONY.
cooling, deposits it again in tKe form of kermes without farther decern*
position. (Duflos.) The hoiling solution does not take up pentasulphide
of antimony. (Rammelsberg.) The salt dissolres in 2-9 parts of water at
15^ (Rammelsberg), in 4 parts of cold, and in 1 part of boiling water.
(Duflos.) It is not soluble in alcohol, eren when the alcohol is rather
largely diluted with water. (Rammelsberg.)
I. Chloride of Antimony and Sodium. — Terchloride of antimony
dissolves in solution of common salt without producing a precipitate, and
the solution yields large crystals on eraporation. (Liebig, Handworterh.
1, 423.) Crystallizes in plates, haying the composition dNaCl,SbCl'.
(Poggiale.)
Antimont and Barium.
A. Antimonite of Baryta. — When a boiling dilute solution of
antimonite of potash is added slowly and in small quantities at a time to
a boiling dilute solution of chloride of barium, small flat needles, having a
silvery lustre, are deposited. These crystals are permanent in the air,
difficultly soluble in water, and give up baryta to acids. (Berzelius.)
B. Antimoniate of Baryta. — White powder; not decomposible
by carbonic acid; scarcely soluble in water. (Berzelius.)
C. Sulphantimonite of Barium. — 1. Prepared by strongly igniting
a mixture of sulphide of antimony with heavy spar and charcoal. — Red-
dish-brown, slag-like, infusible mass, which dissolves in water, with sepa-
ration of a yellowish-brown powder. (Pagenstecher.) — The transparent
tables and radiated crystals, which Pagenstecher obtained by evaporating
and cooling a solution of this salt, and which, when exposed to the air,
rapidly turned yellow and then red, — or when dissolved in water, evolved
hydrosulphuric acid gas, and gave a yellowish-red precipitate— probably
belong to the next compound.
D. Sulphantimoniate op Barium. — Hydrated. — Obtained by dis-
solving pentasulphide of antimony in solution of sulphide of barium,
evaporating the yellowish filtrate to a small bulk, and then mixing it with
alcohol. — Unless alcohol is added, the crystallization is difficult. When
pentasulphide of antimony is dissolved m baryta-water, antimoniate of
baryta is separated, and the same compound formed. — By igniting a mix->
ture of heavy spar with charcoal, grey sulphide of antimony, and sulphur,
and exhausting the mass with water, a few crystals are also obtained. —
White needles, arranged in stellate masses. When exposed to the air,
they turn brown, from separation of pentasulphide of antimony. When
heated, they leave a brown mass without previously fusing. (Rammels-
berg.)
3BaS
SbS*
6H0
Calculation.
253-8 .... 49-11
209-0 .... 40-44
640 .... 10-45
Rammelsberg.
48-85
41-18
9-91
3BaS,SbS* + 6Aq.
516-8
.... 10000
99-94
H E. Chloride op Antimony and Barium. — 26aCl, SbC -|- 5 Aq.
-^Formed by adding a strong solution of chloride of barium to acid
SULPHANTIMONIATB OF CALCIUM. 389
hjdroclilorate of antimonic oxide. Crystallizes in fine needles grouped
in stellate masses. Similar compounds maj likewise be obtained with
strontia, lime, and magnesia. (Poggiale.) IT
Antimony and Strontium.
SuLPHANTiMONiATG OP STRONTIUM. — ffydrcUed.'^Wheix an aqueous
solution of sulphide of strontium is saturated with pentasulphide of
antimony, a solution is formed which does not crystallize, but, on the
addition of alcohol, deposits this compound in the form of a dense, oily
liquid. The liquid contains rather more than 3 atoms of SiS to 1 atom
ofSbS'. (Rammelsberg.)
Antimony and Calcium.
A. Antimonite of Lime. ^-Prepared by double decomposition.— «
White crystalline powder, insoluble in water, (fierzelius.)
B. Antimoniatb of Limb. — ; Obtained likewise by double decom-
position. — White semi-crystalline powder, nearly insoluble in water.
(Berzelius.)
Eomeite, — Square octohedrons (Fig. 21) e : «^=1 11®; e : e behind=69®.
(Dufr^noy.) Insoluble in acids before ignition with carbonate of potash;
contains in 100 parts: lime 16*67, mansanous oxide 2*60, ferrous oxide 1*20,
antimonious acid (or perhaps one of the other oxygen compounds of anti-
mony) 7931, silica 0*64 (excess 0*42). (Damour.) Hence the formula is
about (CaO; MnO; FeO),SbO^; though the quantity of SbO^ is rather too
small.
C. SuLPnANTiMONiATB OF Calcium. •— The product obtained by
igniting out of contact of air a mixture of grey sulphide of antimony,
sulphur, and caustic lime or its carbonate, is the Calx Antimonii cum
Sulphure Hoffmanni. The following are the proportions recommended :
4 pts. of sulphide of antimony, 3 pts. of sulphur, and 10 pts. of burnt
oyster shells. (Bremser.) — 1 pt. of sulphide of antimony,I2 pts. of sulphur,
and 8 pts. of purified oyster shells {PharmacopCBia Boruss. ed, 5.) — 1 pt. of
sulphide of antimony, 1 pt. of sulphur, and 4 pts. of purified chalk.
(Bucholz.) — The result is a mixture, either of sulphantimoniate of calcium
and a compound of antimonic oxide with lime, or of sulphantimoniate of
calcium and sulphate of lime. — If the ignition be stopped too soon, a
brown powder is obtained; but by continuing it for upwards of an hour, a
brownish-yellow or yellowish -white powder is produced, which must be
preserved in well-closed bottles, as it evolves hydrosulphuric acid in tho
air, and turns brown. When repeatedly boiled with a large quantity of
water, it dissolves partially — ^the solution {Solutio Calcis Antimonii cum
Sulphure) evolving sulphuretted hydrogen on the addition of hydrochloric
acid, and depositing pentasulphide of antimony, which, when the mixture
has been sufficiently ignited, amounts to about \ of the sulphide of
antimony originally used.
By boiling 1 part of grey sulphide of antimony with water and 3 parts
of lime, a colourless filtrate is obtained, which has a hepatic taste, and,
when. evaporated in a retort to a small bulk, deposits a yellowish-white,
amorphous powder, which turns brownish-red in the air, and gives a pre*
390 ANTIMONY.
cipitate of pentasulpbide of antimony with acids, and of pentasnlphide of
antimony and lime with alcohol, — so that the filtrate no longer erolves
hydrosulphuric acid on the addition of acids. (Pagenstecher, Eeperi.
14, 217.)
By boiling pentasnlphide of antimony with sulphide of calcium and
water, a yellow solution is obtained, which does not yield any crystals,
but deposits an oily liquid on being mixed with alcohol. The solution
contains 33*7 per cent, of pentasnlphide of antimony and 66*3 of protosul-
phide of calcium. (Rammelsberg.) [This must be an error of the press
in Rammelsberg*s memoir; for since, according to Rammelsberg, the com-
pound consists of dCaS,SbS', the 66 '3 must belong to the sulphide of
antimony, and the 33*7 to the sulphide of calcium.] ,
Antimony and Magnesium.
SuLPHANTXMONiATE OF Magnebium. — By dissolving pentasulpbide of
antimony in water wherein hydrate of ma^esia is diffused and through
which a current of hydrosulphuric acid is passed, a yellow uncrystallizable
liquid is obtained, from which alcohol precipitates an oraoge*coloured
substance, composed of dMgS,SbS^ nearly. (Rammelsberg.)
Antimony and Silicium.
Htdrofluate of Silica and Antimonic Oxide. — Crystallizes by
slow eraporation, in prisms which crumble to powder when dried in tho
air, and dissolve readily in water if an excess of acid is present. (Ber>
zelius.) — A mixture of sulphide of antimony and antimonic oxide imparts
a yellow or hyacinth-red colonr to glass.
Antimony and Molybdenum.
Molybdate of Antimonic Oxide. — Precipitated as a yellow powder,
which is soluble in boiling water. (Berzelius.)
Antimony and Vanadium.
Vanadiate of Antimonic Oxide. — A solution of tartar-emetic gives
with vanadiate of ammonia a yellowish red-brown coagulum, which dis-
solves in the liquid on agitation, forming a solution of the same colour.
(Prideaux.)
Antimony and Chromium.
Chromate of Antimonic Oxide. — Chromate of potash gives with
acid hydrochlorate of antimonic oxide, a brownish-yellow precipitate,
wliicb dissolves in an excess of the antimony-salt, forming a green sola-
tion (Thomson); probably from formation of chromic oxide.
ANTIMONY AND ARS£NIC. 391
Antimony and Ubanium.
A. Amtimoniatb of Uranous Oxide. — Hydroclilorate of uranous
oxide gives "with an excesa of mono-antimoniate of potash^ a gelati-
nons green precipitate, easily soluble in excess of the nydrochlorate of
uranous oxide. The precipitate when ignited loses 14*75 per cent of
water, and turns yellowish-brown. Boiling solution of potash extracts
the whole of the antimonic acid from the precipitate while still moist, but
only a portion after drying. Nitric acid separates the uranium in the
form of uranic oxide, leaving the antimonic acid unaltered. Hydrochloric
acid dissolves the salt only when hot and in a concentrated state; the
solution deposits antimonic acid on the addition of water. (Rammelsberg,
Fogg. 59, 27.)
Approximate calculation. Rammelsberg.
5UO 340 .... 34-62 34*94
3SbO» 607 .... 61-63
^ 15HO 135 .... 13-76 14-75
5U0, 3SbO»+ 15Aq 982 .... 10000
B. URAmc SuLPHANTiMONiATE. — A oompound of pentasulphide of
antimony with sesquisulphide of uranium. — A solution of sulphanti-
moniate of sodium gives a yellowish-brown precipitate with hydrocnlorate
of uranic oxide and ammonia. (Rammelsberg.)
Antimony and Manoanbbk.
A. Antimoniate of Manoanoub Oxide.— Prepared by double de-
composition. — Snow-white, permanent in the air, sparin^y soluble in
water. When ignited, it turns grey, but at a hiffber temperature, again
becomes white, without exhibiting any glow; after this, acids have no
longer the power of separating the maogaoons oxide.— (Benelins.)
B. SuLPHANTiMONiATE OF Makoanese. — The solutlon of sulphanti-
moniate of sodium gives with sulphate of manganous oxide, a white
cloudiness, and after a while, a dense reddish-brown precipitate, which is
not altered by boiling with the supernatant liquid, but becomes reddish-
grey when washed and dried, in consequence of oxidation. (Rammelsberg.)
Antimony and Arsenic.
A. Arsenide of Antimony. — a. Seven parts of antimony unite with
one part of arsenic, forming a grey, hard, very brittle and fusible mass.
(Bergman.) — 6. By heating a mixture of 15 parts of powdered antimony
and 20 parts of powdered arsenic, 16'1 parts of arsenide of antimony are
formed, without any emission of light or heat. This alloy is as brittle
and has the same laminar structure as antimony, but is whiter, and fuses
readily. (Gehlen.) By exposure to a white heat, out of contact of air, the
arsenic is completely volatilized; also in a current of hydrogen gas, even
at a low red heat. (Liebig.) — c. Found native, having a fine granular
fracture, and specific gravity = 6*13 (Thomson), 6'203 (Rammelsberg.)
Gives up all its arsenic wiien ignited in a current of hydrogen gas.
(Rammelsberg.)
393 ANTIMONY.
Native. Ramrndsberg. Thornton.
Sb 129 .... 36-44 37*85 .... 46-61
3Afl 225 .... 63*56 6215 .... 3851
SbA8» 354 .... 100-00 IZ! 10000 Z 85*12
B. Arsenitb of Anttmonic Oxide. — ^When an aqueouB solution of
arsenic acid is digested with antimony, arsenite of antimonic oxide is
formed, and is precipitated on diluting with water. (Berzelius.) This
salt may also be obtained in the dry way, bj heating arsenic with anti*
monic acid; it then forms a transparent, vitreous, fused mass.
C. Arseniate of Antimonic Oxide. — Arseniate of potash produces
a white pulverulent precipitate in acid hydrochlorate of antimonic oxide.
(Berzelius.)
D. Arseniate of Antimonic Acm. — Formed by heating a substance
which contains both arsenic and antimony, with nitric acid, and diluting
the solution with water; whereupon the compound is precipitated as a
white powder, soluble in nitric or hydrochloric acid. The latter solution,
when evaporated to a small bulk and treated with water, is resolved into
antimonic acid which is precipitated, and arsenic acid which dissolves;
the latter may be purified from the still adhering antimonic acid by
repeated evaporation to dryness and re-solution in water. (Berthier.)
£. Compound of Tersulphidb of Arsenic with Tersulphidb of
Antimony. — Aurora-red precipitate, which fuses readily to an orange-
yellow, transparent liquid. (Berzelius.)
F. Compound of Pentasulphidb of Arsenic with Tersulphidb
OF Antimont. — The sodium compound precipitates from salts of antimo*
nic oxide a reddish-yellow, easily fusible substance. (Berzelius.)
G. Arsenide of Antimont and Potassium. — Prepared by igniting
a mixture of 2 parts of antimony with 1 part of arsenious acid and 2 parts
of cream of tartar in a covered crucible, for two hours. The alloy evolves
arseniurctted-hydrogen gas with water. (Serullas.)
Other Compounds of Antimony.
With Bismuth, Zinc, Tin, Lead, Iron, Cobalt, Nickel, Copper, Mercury,
Silver, Gold, Platinum, and Palladium. These alloys are brittle and white
when the antimony predominates.
393
Cbaptbb XXVI.
TELLURIUM,
Muller ▼. Reiclienstem. Abhandl, einer PrivatgeselUchafi in B'dkmm.
Jahrg, 1, Qvart, 1, 2, and 3.
Klaproth. CreU, Ann. 1798, 1, 91; also his BeUrage, S, 1. — Further^
GUb. 12, 246.
Sir H. Davy. Hydroteliurio acid. FhU. Tram. 1810, 27; also Schw.
5,348; also 6^. 37,48.
Boraelius. Sckw. 6, 311; 34,78. — Sulphotellurates. Pogg. 8, 411.—
Tellarium in general. Fogg. 28, 392; 32, 1 and 577.
Stnonymes. Sylvan, Tellur, Tetture.
History. Miiller ▼. Reiohenstein, in 1782, showed that tellarium ores
contain a peculiar metal — a statement which was confirmed by Klaproth,
in 1798. HydroteUuric acid was discoyered by Sir Humphry Dayy. For
nearly all the other facts relating to tellurium, we are indebted to the
untiring labours of Benelius.
Sources. As natiye tellurium (containing small quantities of iron and
gold); as tellurous acid; as telluride of bismuth; as telluride of lead,
associated likewise with foliated tellurium; as telluride of silyer; as
yellow teUurium and graphic tellurium (telluride of gold and silyer).
Freparation. a. From Telluric BismtUhy which contains about 60 per
cent, of bismuth, 36 tellurium, and 4 sulphur-HSometimes also selenium,
silyer, and matrix.
The ore is pulyerized; the earthy portions, which contain telluric
oxide, and are therefore useful, are separated by washing ; the metaUic
powder mixed with an equal weight of carbonate of potash or soda, and
made up into a stiff paste with oliye oil ; the mixture heated in a well-
dosed porcelain crucible, carefully at first (to preyent frothing oyer) till
the oil has become carbonized, and afterwards to a full white heat. The
whole is then left to cool with the coyer on ; the dark brown porous mass
quickly pulyerized; the powder thrown on a filter; water exhausted of air
by boiling and then cooled out of contact of air, is poured upon it; and
lastly, it is washed thoroughly by means of the wash-bottle with water
thus exhausted, the air being all the time excluded as completely as pos-
sible. The residue left on the filter consists of charcoal, bismuth, and a
trace of tellurium. The tellurium is precipitated from the dark-red fil-
trate by blowing air through it with the bellow0| and then collected on a
594 TSLLUUUM.
filter. The filtered liquid thus obtained is yellow, and contftinB sulphide
and selenide of tellurium^ dissolved bj sulphide of potassium; these com-
pounds may be precipitated by hydrochloric acid. The tellurium, after
being washed on the filter, is uised, and subsequently freed by distillation
from /<old^ iron, copper, and manganese, which are left behind in combina-
tion with a small quantity of tellurium. As the distillation of tellurium
requires a high temperature, the fused metal is placed in an elongated
dish, and introduced into a slightly inclined porcelain tube, through
which, during the ignition, a stream of hydrogen gas is passed. (Berzelius.)
The object of fusing with carbonate of potash and charcoal is to free
the tellurium from sulphur, selenium, and arsenic. The arsenic volatilizes,
and the sulphur, together with the selenium, remains dissolved, after the
current of air has been passed through the aqueous solution, provided
that solution contains excess of alkali. The three substances just men-
tioned cannot be separated from tellurium by simple distiUatioo.
(Berzelius.)
b. From Tdluride of Silver, containing 35 per cent, of tellurium, from
61 to 46 of silver, and from 1 to 18 of gold. — 1. Two bulbs are blown on
a glass tube half an inch apart, and the telluride of silver is heated in
x>ne of them, while a current of chlorine gas is passed through the tube,
the heat being kept up till the chloride of silver formed in the first
bulb fuses to a transparent liquid, containing no insoluble residue. Proto-
chloride of tellurium is first formed, and mixes with the chloride of silver,
producing a black liquid; more chlorine is then absorbed and bichloride of
tellurium formed, which distils over into the second bulb. When the
chlorine which escapes is passed through water, it gives up chloride of
sulphur, chloride of selenium, a trace of chloride of antimony, and a small
quantity of chloride of tellurium. When the decomposition is completed^
the tube is cut in two between the bulbs; the chloride of tellurium dis*
tilled over into the second ;bulb is dissolved in dilute hydrochloric acid, and
the tellurium precipitated from the solution by bisulphite of potash^
Hydrosulphuric acid added to the filtrate precipitates a trace of kermes.
The tellurium obtained by this process is purified by distillation in a
current of hydrogen, whereupon the greater part of the selenium mixed
with it volatilizes in the form of a red vapour; nevertheless a trace of
selenium remains mixed with the tellurium. — 2. The teUuride of silver is
first broken up in a mortar, and rubbed to powder with water. One part
of the powder is then mixed with 1 pt. nitre and 1^ pt. carbonate of
potash, and the mixture heated in a silver crucible, not quite to redness,
till the black colour changes to reddish-grey; the heat is then increased
to redness, the mass left to cool, and then exhausted with water, which
leaves the silver behind in a state of purity. The clear filtrate, which
becomes milky when heated, is evaporated to a small bulk — ^then mixed
with a large quantity of charcoal powder, and evaporated to dryness — the
mass pressed into a crucible, which is then covered and heated to redness-^
and the separation of the tellurium completed as in the extraction of the
metal from telluride of bismuth. (Berzelius.) — 3. The finely pounded ore
is heated in a retort having a receiver adapted to it, with tolerably strong
nitric acid free from chlorine, till the whole is oxidized; the liquid is then
distilled to dryness; the nitrate of silver extracted from the residue with
water; the residual tellurous acid ignited with carbonate of potash and
oil; and the extraction of the tellurium completed as from telluride of
bismuth. The charcoal which remains after exhaustion with water, con-
tains but a small quantity of reproduced telluride of silver. (Berzelius.) —
TELLURIUM. S95
4. One part of pounded telloride of silyer is introduced in snccessiye por-
tions into a crucible containing 1 part of carbonate of potash in a state of
fusion; a stronger heat is afterwards applied, and the crucible broken
-when cold. A small quantity of silver is found at the bottom; above it
is a layer of telluride of silver; and at the top, a stratum of carbonate of
potash, which contains a small quantity of tellurous acid and is to be kept
for the treatment immediately to be described. The telluride of silver
thus obtained is pounded up and again added in successive portions to an
equal weight of carbonate of potash, each portion of telluride of silver^
however, being mixed with nitre. The effervescence produced on the
addition of each portion of nitre and telluride of silver must be allowed to
subside before a iresh quantity is added. After the whole has been added,
the mass is left to cool, and the crucible broken. The whole of the silver
is found at the bottom, in a state of perfect purity, and the whole of the
tellurium above it in the form of tellurate of potash. This salt ^together
with the carbonate and tellurite of potash formerly obtained) is mixed
with a small quantity of charcoal, and thrown by small portions at a time
into a red-hot crucible, each portion bein? added as soon ajs the effer-
vescence caused by the last has subsided: if the quantity of charcoal is
insufficient, a piece of charcoal is placed upon the surface of the melted
mass. This mass, which consists of telluride of potassium and carbonate
of potash, is then, after cooling, dissolved in a tolerably large quantity of
water, the carmine-coloured solution exposed to the air in flat dishes till
it has lost its colour, and the precipitated tellurium collected on a double
filter, and washed, first with water, then with a small quantity of hydro-
chloric acid, then again with water, and fused together after diying.
(Hess. Pogg. 28. 407.)
c. From Foliated Tellurium, which contains 13 per cent, of tellurium^
63 lead, together with copper, gold, antimony, and sulphur — ^probably in
the form of telluride of gold, sulphide of lead, and sulphide or antimony.
— 1. The finely pounded ore is freed from the metallic sulphides by
repeated boiling with strong hydrochloric acid and washing with boiling
water; the residual telluride of gold treated with nitric acid; the tellurium
solution poured off from the gold and evaporated to dryness; the residue
of telluric oxide dissolved in hydrochloric acid; and the tellurium precipi-
tated from the solution by sulphurous acid. (Berthier.) — 2. A mixture of
10 parts of the ore, 8 or 9 parts of nitre, and 20 parts of dry carbonate
of potash or soda is heated to complete fusion in an earthen crucible; the
mass poured out, pulverized, and mixed with 8 or 9 parts of nitre and
10 parts of fresh ore; the fusion repeated; and the melted mass poured
out, pulverized, and again fused in the same crucible with 10 parts of fresh
ore and 8 or 9 of nitre : at the third fusion, however, a stronger heat is
applied, the fused mass left to cool in the crucible, the crucible broken^
and the greyish-white, crystalline regulus, amounting to about 15 per
cent., separated from the slag. The latter is pulverized, dissolved in a
large quantity of water, and the solution filtered from the oxides of lead
and antimony. (As these oxides often still contain gold, they are reduced
with black flux, and the gold separated by cupellation.) The alkaline
liquid is supersaturated with sulphuric or hydrochloric acid; separated
from the precipitated gelatinous silica; the tellurium precipitated from it
by the immersion of iron rods; and the black powder, after washing and
drying, fused together in a glass tube or a retort. The tellurium thus
separated is free from iron, provided the iron rods arc perfectly bright and
the liquid kept strongly a<nd. [Antimony may, however, be mixed with
396 TELLURIUM.
it.] The llqnid filtered from the tellnriam should no longer giro a preci-
pitate with hjdrosulphuric acid. If the metallic regains obtained as
above be heated with nitric acid^ which takes np lead and sometimes also
a small quantity of tellurium — then with hydrochloric acid — and after-
wards tboroughfj washed, a residue of pure gold is obtained. (Berthier,
Ann. Gkim, rhyB, 51, 156.)
d. From Native Tellurium^ which contains 97 per cent, of tellurinm,
together with small quantities of iron, gold, and sulphur. It is dissolved
in aqua-regia; the solution diluted with as much water as can be added
without produciug a precipitate, and then supersaturated with caustic
potash; and the liquid, which contains tellurite of potash, filtered from
the oxides of iron and gold, and neutralized exactly with hydrochloric
acid. The precipitate of telluric oxide, after being washed and dried, is
mixed with oil, or with -^ of its weight of charcoal, and heated in a glass
retort. The reduced tellurium partly collects at the bottom of the retort,
and partly sublimes in the neck. (Klaproth.) — Since tellurous acid preci-
pitated by Klaproth's method contains potash, the tellurium reduced from
it contains potassium, which must be separated by fusion with a small
portion of tellurous acid. (Berzelius.)
[Gersdorf and Kolreuter's modes of preparation. {^N» Tr, 8, 2, 285;
Schw. 62, 213.) — Separation of tellurium from selenium^ according to
Berzelius (^Pogg. 32, 11), according to Wehrle. (JSeiUekr, Phyt. M<U^ 3,
317J
To purify telluric oxide from the oxides of lead, copper, &c. it must
be dissolved in bihydrosnlphate of potash; filtered from sulphide of lead,
sulphide of copper, &c. ; the sulphide of tellurium precipitated from the
filtrate by acids, and heated in a retort at a very gradually increasing
temperature, till tlie whole of the sulphur, together with any selenium
and arsenic that may be present, has passed over. If the heat be raised
too quickly, a small quantity of tellurium likewise volatilizes. (Berzelius.)
[For the separation of tellurium by sulphurous acid, see page 399 [*
Properties. — Crystalline system the rhombohedral. Primary form,
an acute rhombohedron, {Fig, 151); also {Figs, 153, 135,) a six-sided
prism shortened to a table; also an obtuse rhombohedron. {Fig, 141);
r» : r* {Fig. 141), according to Phillips=115^ 12'; also r* : t* (Fig, 151)
=86° 3'. Cleavage parallel to r and p {Figt, 151 and 153). Breithaupt,
Pogg* 7, 527; Sckw, 52, 168.) On distilling teUurium in hydrogen gas,
(p. 394,) a portion of it sublimes in shming, flat, elastic needles.
(Berzelius.) When tellurium solidifies quietly after fusion, its surface
exhibits a crystalline structure. (Berzelius.) Specific gravity, 6*115
(Klaproth), 61379 (Magnus), 6*2445 (Berzelius), 6*343. (Reichenstein.)
Very brittle; easily pulverized. — Tin- white, with strong metallic lustre.
•—-When obtained in the finely divided state by precipitation or subli-
mation, it forms a brown powder. (Magnus.) When precipitated by the
action of the air from a very dilute solution of hydrotellurate of potash,
it causes the liquid to appear blue by transmitted light. (Berzelius.)—
Fuses less easily than lead, rather more easily than antimony; after
fusion, it contracts very strongly on cooling. Hence, when it is slowly
cooled, a large cavity is formed in the middle of the mass ; when, on the
contrary, the cooling is rapid, the surface solidifies, while the interior
still remains liquid; and as the inner part solidifies, numerous small
cavities are formed in it, which diminish the specific gravity. (Berzelius.)
Tellurium boils at a temperature higher than the softening poiut of
TELLURIC OXIDE. 39?
glass, and is then converted into a yellow vapour, Laving the colour of
chlorine gas. (Berzelius.) When heated to redness in a retort, it sub-
limes in the neck, in the form of shining drops. (Klaproth.)
Compounds of Tellurium,
Tellurium and Oxygen.
Berzelins did not succeed in forming a protoxide of tellurium. 64 parts
Te and 80 parts TeO' intimately mixed and heated to various degrees
did not form a definite compound. Protochloride of tellurium decomposed
by dry carbonate of soda yielded a mixture of tellurium and tellurous
acid, &c.
A. Telluric Oxide or Tellurous Acid. TeO^
Found native in small white beads having a tinge of greyish-yellow
and a crystalline texture. (Petz, Pogg. 57, 477.)
Formation. — Tellurium heated in the air somewhat above its melting
point, bums with a bright blue flame green at the edges, and is con-
verted into a white cloud — which, according to Berzelius and Magnus,
has a faint, unpleasant odour, different from that of selenium — and con-
denses on cold bodies in the form of a white oxide. The horse-radish
odour, which Klaproth observed at the same time, proceeded from an
admixture of selenium. — 2. Nitric acid and heated sulphuric acid convert
tellurium into telluric oxide, the former giving off nitric oxide, the latter
sulphurous acid. Tellurium does not decompose vapour of water at a red
heat. (Regnault.)
Preparation, — A solution of tellurium in nitric acid is left to itself
for a considerable time : the purer and more concentrated it i.?, the more
uickly does the telluric oxide separate from it in the crystalline form.
he oxide thus deposited does not contain more than | per cent, of
nitric acid, which, on the application of heat, is given off with some
decrepitation. (Berzelius.) — 2. A solution of tellurium in nitric acid is
evaporated to dryness and gently ignited. (Berzelius.) — 3. A boiling
solution of bichloride of tellurium in hydrochloric acid is mixed with
boiling water, and left to cool slowly. (Berzelius.)
Properties. — When prepared by method (1) it forms a crystalline
crust, consisting of octohedrons, which may be distinguished by the
microscope; it is colourless while moist, and milk-white when thoroughly
dry. That prepared by (3) forms octohedrons, distinguishable by the
naked eye. Organic matter, which is very readily taken up by tellurous
acid, gives it a pale yellow colour. When tellurous acid thus contami-
nated is heated in a glass tube, it blackens, emits slight fumes, and then
becomes colourless. When slightly heated, it turns yellowish; a stronger
heat causes it to assume, for the time, an orange-yellow colour. At an
incipient red heat, it fuses into a transparent, dark-yellow liquid, which,
on exposure to the air, volatilizes with emission of slight fumes. On
cooling it solidifies, evolving sufficient heat to raise it again to low red-
ness, and forms a white, highly crystalline mass, translucent when very
slowly cooled, which easily separates from the crucible, and may be
^'
398 TBLLURIUM.
broken by the fingera Into ciystalline fragments. Single diope often
solidify to a transparent glass. Volatilizes and sublimes, but at a tern-
peratore much higher than the subliming point of the metal> in the
form of a soft mealy powder : it may, therefore, be fused in a covered
crucible without much loss. The powder reddens moist litmus-paper,
but not till after some time ; it is tasteless at firsts but afterwards excites
an unpleasant metallic taste.
Te
20
Calculation*
64 .... 80
16 .... 20
Berzelios.
8004
19-96
• •••
••••
• ■••
Klaproth.
8314
16-86
TeO»
80 .... 100
10000
100-00
Decomposed by charcoal at a comparatively low temperature, with a
kind of detonation. On charcoal before the blowpipe, it is decomposed
with effervescence, the flame exhibiting a green colour, and the greater
part of the tellurium evaporating : part of the metal however bums again,
and is reconverted into telluric oxide, which forms a white deposit on the
charcoal. Slowly reduced by hydrogen gas, at a temperature not lower
than that at which the metal sublimes. If selenious acid is likewise
present, a red mealy powder is deposited in the tube. (Berzelius.)
CamhincUtons. — a. With Water. — «. Hydrate of Telluric Oxide or
Hydrate of Tellurous Acid. — 1. Formed by precipitating a solution of
tellurium in nitric acid of specific gravity 1 '25, with water. — 2. By
fusing dry tellurous acid with an eqnal weight of carbonate of potash^
dissolving the resulting tellurite of potash in cold water, and adding
nitric acid in scarcely perceptible excess. The mixture is set aside for'a
considerable time, and stirred frequently, so that no tellarite of potash
may remain undecomposed, and the tellurous acid thrown on a filter. —
3. By dissolving dry tellurous acid in caustic potash, and proceeding in
the same manner. The acid thus obtained is washed with ice-cold water,
and dried in the air at a temperature below 12°. (Berzelius.)
White voluminous flakes, which are earthy after drying, instantly
redden moist litmus-paper, and have a sharp metallic taste. At 40"^, and
frequently even at lower temperatures, the hydrate is resolved into grains
of anhydrous tellurous acid, so that a milky mixture of it with water is
converted into a clear liquid, containing crystalline grains of the dry
acid. (Berzelius.)
/3. Aqueous Tellurous Acid. — The dry acid dissolves but very
sparingly in water, forming a tasteless liquid, which does not redden
litmus, and, on evaporation, leaves the acid in the form of a finely
pulverulent film. The hydrate dissolves in water with tolerable facility.
The solution redden litmus, and has a metallic taste: when heated above
40^, it becomes milky and loses its power of reddening litmus, because
it then deposits the anhydrous acid in the form of fine grains : when freely
evaporated, it leaves the anhydrous acid, together with a small quantity
of the hydrate. (Berzelius.)
6. With Acids, forming the Salts of Telluric Oxide or Telluric
Salts. — Anhydrous telluric oxide dissolves but very sparingly in most
acids ; hydrochloric acid alone dissolves it somewhat more freely. The
hydrate is easily soluble. The sulphate and nitrate are likewise obtained
by treating the metal with the corresponding acids. Telluric salts are
colourless, nnless they contain a coloured acid ; they have a disagreeable
TELLURIC SALTS. 399
metallio taate^ closely resembling thai of antimonic salts (Berzelius) }
they are strongly emetic TKolreuter). After ignition with potash and
charcoal^ they yield a rea solution in water. (Berzelius.) Phosphorus
precipitates metallic tellurium from these salts (Berzelius); phosphorus
dissolyed in alcohol gives a white precipitate, which soon turns black.
(Fischer.) Sulphurous acid precipitates metallic tellurium. (Wehrle,
Zeitsch, Phys. Math, 9, 138.) Hence a solution of sulphurous acid or
bisulphite of ammonia, potash, or soda, forms a useful reagent for
separating tellurium. To prevent the water in which the sulphurous
acid and its salts are dissolved, from precipitating a basic salt of tellu<
rium, which would then no longer be reduced, the solution must be
strongly acidulated with hydrochloric acid. If the solution is cold, it
remains transparent and colourless for a short time after misdng, but
afterwards becomes brownish and turbid from precipitation of tellurium :
if it is warm, a turbid mixture is immediately produced, blue by trans-
mitted and green by reflected light. The warmer and stronger the solu-
tion, the more quickly and completely is the precipitation effected. In
the cold, the precipitation is never complete, even if the sulphurous acid
is in excess ; hence fresh turbidity is produced on heating the liquid ;
but if the solution be heated for a long time in the air, the excess of
sulphurous acid will be driven off, and then the tellurium may be oxidized
by the air and redissolved ; towards the end of the process, therefore,
sulphite of potash must be added in excess, and the liquid heated till it
boils. If the tellurium-solution contains nitric acid, the metal is still
precipitated, but redissolves with evolution of nitric oxide. If the
liquid contains selenious acid, selenium is precipitated together with the
tellurium. Certain metals also, which, when alone, are not reduced by
sulphurous acid, are, nevertheless, precipitated in company with the
tellurium, — e. g., silver and gold completely, bismuth and copper in small
quantity, iron in still smaller quantity. In washing the precipitated
tellurium, the filter must be kept constantly full of the liquid, as other-
wise the tellurium will oxidate, and be dissolved by the acid still present.
It is, therefore, advisable to concentrate the filtrate by evaporation, and
then treat it with sulphite of ammonia, in order to precipitate any
tellurium that may have been dissolved.
Tellurium is precipitated in the metallic state by zinc, tin, antimony
(Klaproth), iron, copper (Berzelius), cadmium, lead, and mercury.
(Fisdier.) It is generally precipitated in the form of a black powder,
which acquires metallic lustre by rubbing; lead however precipitates
it in the dendritic form. It is difficult to ensure complete precipita-
tion : towards the end of the reaction, a basic salt of tellurium is often
precipitated, or a compound of tellnrous acid with the oxide of the
other metal. (Fischer, Fogg, 12, 502.) Protochloride of tin and green
vitriol precipitate the tellurium in the metallic state. The former gives
a black fibrous precipitate, and, if the solution is very dilute, colours it
brown after a while: this colour is still apparent when only 1 part of
telluric oxide is contained in 60,000 parts of the liquid. Green vitriol
does not precipitate tellurium, unless the telluric salt is perfectly neu*
tralized, and of a particular degree of concentration. (Fischer, Fogg. 13,
257.)
The solutions of tellurium in inorganic acids (not those which contain
vegetable acids), provided the acid is not in very great excess, yield,
when largely diluted with water, a white precipitate, consisting partly^ of
hydra ted telluric oxide, partly of a basic salt, from which the remaining
400 TELLURIUM.
portion of acid may be extracted by repeated washing with warm water;
the dilate acid above the precipitate retains bat a small quantity of
tellario oxide in 8olation.-»Caastic ammonia, potash, and soda, and
likewise their monocarbonates and bicarbonates precipitate the hydrated
oxide in thick white flakes, which dissolve completely in excess of the
alkali (in the alkaline carbonates, however, only on the application of
heat). — Phosphate of soda gives a white precipitate.— Hydrosulphnrio
acid and hydrosalphate of ammonia throw down black-brown sulphide of
tellarinm, easily soluble in excess of the alkaline hydrosnlphate. — Acetate
of lead and nitrate of roercurous oxide give, according to Fischer, a white
precipitate; an ammoniacal solution of oxide of copper gives a greyish-
bine precipitate. — Tincture of galls throws down cream-coloured flakes. —
No precipitate is produced by oxalic acid, or by ferrocyanide or fer-
ricyanide of potassium.
€. With Salifiable bases, forming the Salts ov Tbllurous Acid;
Tellurites. The tellurites of the soluble alkalis may be formed by
direct combination, either in the dry or in the moist way. Anhydrous
tellurous acid dissolves very slowly in aqueous ammonia, easily in
aqueous potash or soda, and only by continued boiling in aqueous carbo-
nate*of potash or soda: it may, however, be easily fused with carbonate of
potash or soda> carbonic acid being driven off. The hydrated acid
dissolves readily in warm aqueous solutions of the caustic alkalis or their
carbonates; the latter are thereby converted into bicarbonates, the carbonic
acid not escaping unless heat is applied. The other salts of tellurous acid
are obtained either by fusion or by precipitating the aqueous solution of
an alkaline tellurite with a salt of the less soluble alkalis, or of the
earths or heavy metallic oxides. — The tellurites contain 1 atom of base
with 1, 2, or 4 atoms of acid. They are fusible, and generally solidify in
the crystalline form on cooling; the quadrotelluritee, however, form a
glass. Tellurites are colourless unless they contain a coloured base;
those which are soluble have a metallic taste. Most of them, when
heated to redness with charcoal, yield metallic tellurium, sometimes with
slight detonation: the reduced metal, if roasted in an open tube, yields a
sublimate of tellurous acid. These salts, when reduced on charcoal
before the blowpipe, impart a green colour to the flame. When ignited
with potassium, or with charcoal and carbonate of potash, they yield
telluride of potassium, which dissolves in water, forming a wine-red
solution. With the tellurites of zinc, silver, and a few others, this
reaction does not take pkice. The tellurites of ammonia, potash, and
soda are easily soluble in water; those of baiyta, strontia, and lime are
difficultly soluble ; and those of the earths and heavy metaUic oxides
insoluble. An aqueous solution of a tellurite is decomposed even by the
carbonic acid of the air. Nearly all tellurites dissolve in strong hydro^
chloric acid, and without evolving chlorine on the application of heat;
the solution exhibits the reactions of a salt of telluric oxide, except in so
far as those reactions may be interfered with by the presence of a stronger
base. (Berzelius.)
B. Telluric Acu>. TeO*.
Fomiation. — 1. By fusing tellurous acid with nitrate of potash.—
2. By the action of chlorine on tellurite of potash. — 3. In small quantity,
when telluriuni is dissolved in nitric acid. (Berzelins.)
TELLURIC ACID. 401
Preparation, — 1. One part of tellurous aoid is fused with 1 part of
carbonate of potash (or soda), the fused mass dissolved in water, and at
least 1 part of caustic potash added to the solution ; or tellurous acid is
dissolved in about twice the quantity of caustic potash required to
neatralize it completely. Through the solution of basic tellurite of
potash obtained by one of these methods, chlorine gas is passed till the
precipitate which is at first produced is completely redissolred, and the
liquid smells of chlorine. A few drops of chloride of barium are then
added, to precipitate any snlphuric or selenic acid that may be present;
the liquid filtered, in case of any precipitate being thereby produced ; the
solution supersaturated with ammonia ; and chloride of barium added as
long as tellurate of baryta continues to be precipitated. The precipitate,
which ia very bulky when first formed, ought quickly to aggregate in
crystalline grains; if this change does not take place, the precipitate
likewise contains tellurite of baryta. The precipitate is then dried at
a gentle heat; 4 parts of it digested with I part of oil of vitriol and from
4 to 8 parts of water; the filtrate concentrated to a certain extent in the
water-bath; and then left to crystallize by spontaneous evaporation. The
acid may likewise be separated, though less advantageously, by dissolving
the tellurate of baryta in dilute nitric acid; precipitating the baryta by
sulphuric acid; evaporating the filtrate to dryness in the water-bath, in
order to drive off the nitric acid; dissolving the residue in water; and
crystallizing by spontaneous evaporation. The best crystals are obtained
when sulphuric acid is present. To free the crystals from adhering
sulphuric acid, they are either pounded and washed with alcohol;— or their
aqueous solution is evaporated to dryness in the water-bath; the residue
exposed to the same degree of heat for some hours; then left to cool, and
exhausted with cold water, which extracts scarcely anything but the
snlphuric acid; the residue dissolved in boiling water, which leaves
tellurous acid undissolved ; and the filtrate left to evaporate spontaneously.
The liquid, after being treated with chlorine, may likewise be mixed with
a boiling solution of chloride of lead : the telluric acid will then be pre-
cipitated in the form of tellurate of lead; and the precipitate, after
thorough washing, may be decomposed by hydrosulphuric acid in th^
manner described under (2).
2. A mixture of tellurous acid and nitre is heated, with constant
stirring, till the mass, which at first assumes a dark red colour, is con-
verted into a transparent and colourless liquid. The heat applied must
not be more than sufiicient to bring the bottom of the crucible to dull
redness, because a higher temperature would reconvert the tellurate of
potash into tellurite. From the resulting mass, when cooled and pul-
verized, cold water extracts nitrate, tellurite, and tellurate of potash.
The bitellurate of potash which remains undissolved, is taken up by
boiling water, and the solution neutralized with ammonia, and precipitated
either by chloride of barium or nitrate of lead. The tellurite of baryta
is treated as in method (1). The tellurate of lead, after washing, is
either decomposed, like the tellurate of baryta, by sulphuric acid; or —
since telluric acid is not immediately decomposed by hydrosulphuric acid
at ordinary temperatures — the tellurate of lead may be diffused in water ;
quickly decomposed by a stream of hydrosulphuric acid gas, continued till
the liquid smells of it after being shaken up ; the excess of that acid
quickly removed by the addition of a portion of tellurate of lead set
apart for that purpose; and the liquid filtered and evaporated. (Berzelius.)
The crystallized acid obtained by one of these methods is converted into
VOL. IV. 2 D
402 TSLLUBIUM.
the anhjdroiu acid by heating it not quite to redoesa. If any portion of
the telluric acid has been converted into tellurous acid by the application
of too mnch heat, the tellurouB acid may be diaaolred out by hydrochloric
acid. (Berielius.)
i*rop«^t«f.^-Orange-yellow mass, having the form of crystals.
Caleuktion. BeneUus.
Tc 64 .... 72-73 7277
SO 24 .... 27-27 2723
TeO* 88 .... 100-00 100*00
Dec&mposUiam. — At a temperature much below the melting point of
tellurous acid, telluric acid is resolved into oitvffen gas and white
palveruleni tellurous acid. Strong hydrochloric acid decomposes telluric
acid slowly and only with the aid of beat, the products of the reaction
being chlorine gas and hydrochlorate of telluric oxide.
Combinations, — a. With Water. — a. HydraU of Telluric Acid. —
Formed by heating the crystallized acid to 160^. The crystals are
converted, without change of form, into an opaque mass, which is yellow
while hot, bat turns white on cooling.
Calcuktion. Benelius.
TeO* 88 .... 90-72 90*74
HO 9 .... 9-28 9-26
HO,TcO» 97 .... 100-00 100-00
/9. Crystallised Telluric Acid. — Formed by spontaneous evaporation
of the aqueous solution. Colourless, tolerably large, flattened, six-sided
prisms, with very obtuse four-sided summits (somewhat like Fig, 67),
and often longitudinally striated ; or — if they separate from a solution
containing sulphuric acid, or from a warm concentrated solution — veiy
short eight-sided prisms. Reddens litmus slightly. l*aste not sour but
metallic, very much like that of nitric acid. The crystals retain their
3 atoms of water at 100''; at 160°, they give off 15*6 per cent. (2 atoms)
and leave the hydrate «; at a stronger heat, but below redness, they give
off the remaining 7'9 per cent. (1 atom) of water and leave the anhydrous
acid, which, at a higher temperature, gives off 7 per cent, of oxygen and
leaves Bd'5 per cent, of tellurous acid :
CalcaUition. Berc«Uiifl*
TcO» 88 .... 76-52 76*5
3H0 27 .... 23-48 23*5
8HO,TeO» 115 .... 10000 ZZ 100*0
y. Aqueous Telluric A eic^.^-The anhydrous acid is perfectly insoluble
even in boiling water, and when thrown into water in the state of fine
powder, merely diffuses itself through the liquid, producing a yellow
milkiness. The hydrated acid dissolves easily in hot water, and very
slowly, though completely, in cold water. The crystallized acid dissolves
slowly but abundantly in cold water. One part of the acid dissolves in
1*63 pt. water at 19'o^, and in boiling water in almost any proportion.
The solution evaporated to a syrupy consistence in the water-bath
solidifies in the crystalline form on cooling; when evaporated to dryness
in the water-batl^ it leaves a milk-white, amorphous mass, which, if
TELLURIC ACID. 403
digested in water, after cooling, first separates in translucent flakes and
then dissolves very slowly. The aqueous solution saturated with hydro-
sulphuric acid deposits tersulphide of tellurium, slowly in the cold, more
quickly when heated. From the saturated aqueous solution, strong
alcohol precipitates part of the telluric acid.
Telluric acid does not combine with other aoidsj the anhydrons acid is
insoluble in cold hydrochloric and in hot nitric acid.
&. With Salifiable Bases, telluric acid forms salts called Tellurates*
Telluric add has but slight affinity for bases. The hydrated acid with-
draws from aqueous solutions of alkaline carbonates, only so much alkali
as to form a salt containing 2 atoms of acid. The anhydrous acid is inso-
luble in boiling potash, unless the latter is so concentrated as to solidify on
cooling. Telluric acid forms bibasic, sesquibasic, monobasic, bi-acid, and
quadracid salts. They are all colourless, unless the base is coloured.
The alkaline monotell urates hare a caustic alkaline taste; the bitellnrates
of the same bases have an alkaline reaction, and taste partly alkaline,
partly metallic. At a red heat, tellurates are converted into tellurites,
at the same time fusing, assuming a yellow or brown colour, and
evolving oxygen gas. Many alkaline quadrotellurates which, in the
hydrated state, are colourless and soluble in water, give off water
when heated, even short of redness, and pass into a peculiar state in
which they are yellow and insoluble in aqueous acids and alkalis. Hence
Berzelius assumes the existence of two isomeric modifications of telluric
acid— the insoluble modification occurring in anhydrous telluric acid and
in the de-hydrated yellow salts inst mentioned, and the soluble variety in
the hydrated acid and the ordinary tellurates. Many tellurates, when
heated on charcoal before the blowpipe, yield metallic tellurium, the
reduction being generally attended with slight detonation. The reduced
tellurium, if roasted in an open tube, yields a sublimate of tellurous acid.
Most tellurates, when ignited with potassium or with a mixture of
charcoal and carbonate of potash, yield a mass which gives up telluride
of potassium to water, and thereby colours it wine-red. Most acids,
even acetic acid in excess, abstract the base of the alkaline tellurates; the
aqueous solutions of these salts give a precipitate with tincture of galls.
Solutions of tellurates in cold concentrated hydrochloric acid are not
yellow and give no precipitate with water; but when heated, they evolve
chlorine, thereby becoming yellow, and — if the acid is not in very great
excess — ^precipitable by water: the hydrochloric acid solution heated with
sulphurous acid, deposits metallic tellurium. The tellurates of the more
soluble alkalis dissolve in water with tolerable facility, the quadro-
tellurates being the least soluble : hence a small quantity of alkali added
to the aqueous acid produces a precipitate which dissolves in a larger
quantity of the alkali. The tellurates of the earthy alkalis are but
slightly soluble, those which contain 2 or 4 atoms of acid bein/sr, however,
more soluble than the simple salts. The tellurates of the earths and heavy
metallic oxides are almost insoluble; nevertheless, water extracts from
some of them an acid salt and leaves a basic salt undissolved. The aqueous
solutions of the more easily soluble tellurates give with chloride of barium
a precipitate which is bulky at first, but afterwards becomes granular,
and is soluble in hydrochloric or nitric acid. (Berzelius.)
Crystallized telluric acid is insoluble in absolute alcohol, slightly
soluble in hydrated alcohol.
2d2
4(U TELLURIUM.
Tellurium and Hydrogen.
Ritter (Oilb, 29, 1 48) has sbown that when the nerative electricity of a
voltaic circuit is oond acted into water by means of teiluriam, no hydrogen
is evolved on the metal, but a Hydride of Tellurium is formed, having
strong colouring properties. Sir H. Davy {Gilh. 37, 49) found that the
water surrounding the tellurium acquired a purple tint, from formation of
hydrotelluric acid; and that, by access of air, a brown powder was
precipitated, which he regarded as a compound of tellurium with a
smaller quantity of hydrogen, i,e. as hydride of tellurium. But according
to Magnus {Pogg. 17, t^^l), this brown powder is nothing but metallic
tellurium, and there is no such thing as a hydride of that metaL The
brown powder is precipitated even when thoroughly boiled water is used,
because the oxygen evolved at the positive pole diffuses itself through the
liquid. If the water contains an acid, no .brown powder is deposited,
because the hydrotelluric acid which is then produced, being but slightly
soluble in acid liquids, immediately escapes as gas. (Magnus.)
Hydrotelluric Acid. HTe.
TellureUed Hydrogen, Hydrotellursaure, HydroUllurgas, Tetlur-^
tvasserstoffsiiure, Tellurwasserstofgas, Acide hydroteUuriqtie, Acide tellnr-
hydrique, Gas hydrogene Ulluri,
Preparation. — By digesting telluride of potassium (H. Davy), or
telluride of zinc, or telluride of iron (Berzelius) in a gas generating vessel
with hydrochloric acid ; the gas is received over mercury.
Properties, — Colourless gas, having a disagreeable and peculiar odour,
very much like that of hydrosulphuric acid. When newly prepared, it
reddens litmus; but loses this property by washing with water, either
because the air in the water decomposes the gas, or because the water
withdraws the hydrochloric acid mixed with it. (H. Davy.) ISpecific
gravity = 4-489 (Bineau, Ann. Chim. Phys, 68, 424.)
Te 64 98-46
H 1 1-54
HTe 65 lOOOO
Vol. Sp. gr. VoL Sp. gr.
Tellurium vaponr 1 .... 26*6112 = 1 .... 4*4352
Hydrogen gas 6 .... 0*4168 = 1 .... 0*0693
HydrotcUuric acid gas 6 .... 27*0270 = 1 .... 4*5045
Decompositions, — 1. The gas, when in contact with air, takes fire on
the approach of a burning body and burns with a bluish flame, forming
water and telluric oxide. (H. Davy.) — 2. Chlorine mixed with the gas
immediately precipitates tellurium^ which is soon converted into chloride
of tellurium. (H.Davy.) — 3. Heated tin decomposes the gas, withdrawing
the tellurium and leaving hydrogen gas of the same volume as the hydro-
telluric acid. (Bioeau.) — 4. The gas is decomposed by contact with
various heavy metallic oxides dissolved in acids^ yielding water and a
metallic telluride. (Berzelius.)
SULPHOTELLUROtS ACID. 405
ComuincUians, — a. With water. — Solution of UydrcteUuric Acid*^^
Water absorbs the gas^ forming a pale red liquid, which, when exposed to
the air, tarns brown and deposits metallic tellarium. (H. Davy.)
6. With the soluble alkalis, forming Alkaline HydroUUurateBy
which may likewise be regarded as tellarides of the alkali-metals, e,g^
KO,HTe = KTe-|-HO.
Tellurium and Phosphorus.
Phosphate op Telluric Oxide. — ^White powder, insoluble in water.
(Berzelius.)
Tellurium and Sulphur.
A. Sulphide of Tellurium. — Tellurium and sulphur may be melted
together in all proportions. Sulphur with a small quantity of telluriam
forms a yellowish-red mixture; with a larger quantity, a substance which
is red by transmitted and black by reflected light; and with a still larger
quantity, an opaque, lead-grey mixture. (Berzelius.)
a. jbisulphide, Tdlurotu Sulphide, Sulphotellurous Acid, — 1. Formed
by passing hydrosulphuric acid gas through the solution of a salt of
telluric oxide. — 2. By passing hydrosulphuric acid through a solution of
an alkaline tellurite till that salt is converted into a sulphotellurite of the
alkali-metal, and then precipitating by an acid. The precipitate pro-
duced by either of these methods, wliicn is at first flocculent, brown, and
translucent, soon becomes darker, indeed almost black. — 3. By exposing
a sulphotellurite of au alkali -metal to the air. In this case, the bisulphide
of tellurium is precipitated in the form of a non-crystalline film, destitute
of metallic lustre. (Berzelius.)
Brown-black; under the burnishing steel, it acquires the metallic
lustre and a lead-grey colour. Softens when heated, but without melting
completely; swells up; and, on cooling, solidifies to a blistered, grey mass,
which has a semi-metallic lustre, is easily pulverized, and does not conduct
electricity. When heated in a retort somewhat strongly and for a
considerable time, it is decomposed, yielding a distillate of sulphur — which,
from admixture of a small quantity of tellurium, is coloured dark-red at
first and afterwards black— and a residue of tellurium perfectly free from
sulphur. If the sulphide of tellurium is mixed with a small quantity of
another metallic sulphide, the latter also gives uj) its sulphur, so that a
metallic telluride is left behind. Bisulphide of tellurium dissolves slowly
but completely in boiling potash or soda, forming a deep yellow solution;
when freshly precipitated, it likewise dissolves sparingly in strons; solution
of ammonia, to which it imparts a pale yellow tint ; the ammonia readily
dissolves out any sulphide of arsenic that may be mixed with it.
(Berzelius.)
Tc 64 66-67
2S 32 33-33
TeSa 96 ZZ 100*00
With basic metallic 8ul2>hides, bisulphide of tellurium forms com-
pounds called StUphotellurUes, Those of the alkali-metals and magnesium
are most readily obtained by saturating the solution of an alkaline
tellurite with hydrosulphuric acid gas. If, however, a mouotellurite of
the alkali be used for the purpose, two-thirds of the resulting tellurous
406 TELLURIUM.
aulpbide is preoipitated, because 3 atoms of an alkaline sulphide dis-
solved in water can only take up 1 atom of the tellurons sulphide:
such at least is the relation in the sodium-compound, which is composed
of dNaS^TeS'. It is true that the sulphur-salt, after evaporation to
dryness, may be fused with a larger quantity of tellurons sulphide, but
the excess is left behind on digesting the fused mass in water. From
alkaline bihydrosulphates, snlpho tellurons acid drives out the excess of
hydrosnlphuric acid on boiling, and forms the same solution as above; the
higher sulphides of the alkali-metals are but slowly and imperfectly
decomposed by it. These compounds, mixed with an alkaline tellurite^
are obtained on dissolving bisulphide of tellurium in caustic potash or
soda; probably thus :
9KO + 5TeS« = 3rKO,TeO») + 2(3KS,TeS3).
The sulphotellurites of the earth-metals and heavy metals are obtained
by double decomposition.
The anhydrous sulphotellurites of the alkali-metals are brownish
yellow ; the crystallized hydrates and the aqueous solutions pale yellow.
The anhydrous sulphotellurites of the alkali-metals may be ignited with-
out decomposition out of contact of air, and, at ordinary temperatures^
remain unaltered when exposed to the air. In the state of solution they
are quickly decomposed, the alkaline sulphide being converted into a
hyposulphite, while the bisulphide of tellurium separates in the form of
a grey metallic film on the surface of the liquid. The alkaline sulpho-
tellurites are easily soluble in water, less easily in alcohol; in the latter
case, sulphide of tellurium is deposited, and the liquid acquires a deep
yellow colour. Acids added to the solutions of these salts throw down
bisulphide of tellurium. The sulphotellurites of the heavy metals, when
ignited in close vessels, are, for the most part, decomposed, the sulphide
of tellurium giving up its sulphur, and the tellurium either combining
with the whole of the more basic metal and separating the whole of the
sulphur— or with only a part of it, — so that the residue consiste, either of
metallic telluride alone, or of a mixture of that compouud with the basic
sulphide. (Berzelius.)
Tersulphide of Tellurium, Telluric Sulphide, Svlpliotelluric Acid. —
A dilute aqueous solution of telluric acid, saturated with hydrosulphurio
acid gas, and set aside in a closed vessel in a warm place, turus brown
without losing its transparency; but afterwards loses its colour, and
deposits tersulphide of tellurium, which covers the sides of the vessel in
the form of a blackish-grey, metal -shining film, easily rubbed oflT in
flakes. The compounds of this sulphide with the more basic metallic
sulphides — the Sulphotellurates — have not been further examined.
(Berzelius.)
c. Tetrasulphide of Tellurium, — Tellurium and sulphur, melted
together in equal parts^ yield a lead-coloured, radiated mass. (Klaproth.)
B. Sulphate of Tellurous Oxide ? — Tellurium immersed in 1 00 parts of
oil of vitriol, at ordinary temperatures, imparts a fine amethyst colour to
the liquid; a small quantity of water added to the solution destroys the
colour, precipitating brown-black flakes of metallic tellurium. (Miiller von
Reichenstein, Klaproth.) — Anhydrous sulphuric acid, sealed up in a tube
with tellurium-powder, produces a red colour at a few points only, pro-
bably arising from moisture; otherwise it remains colourless for a consi-
derable time, even if melted. But if, in consequence of the air not being
TELLURIC SULPHATE, 407
perfectly excluded, tlie sulphuric acid should absorb a trace of water, it
dissolres the tellurium iu large quantity producing a red colour, and
giviug off sulphurous acid. The solution contains 1 part of tellurium to
Q '4 parts of acid; on the addition of water, 09 pt. falls down in the
metallic state, while 0*1 remains in solution as oxide. — Pounded tellu-
rium dissolyes in cold fuming oil of vitriol in the proportion of 1 : 48, the
solution smelling perceptibly of sulphurous acid, even if the moisture of
the air be completely excluded. Oil of vitriol which does not fume,
dissolves only f^jg tellurium, and without perceptible odour of sulphu-
rous acid. With oil of vitriol moderately warmed, tellurium forms a
darker solution, having a stronger violet colour. The metal continues to
dissolve, and the violet colour to increase, so long as the oil of vitriol
does not boil; but when ebullition commences, the solution loses its
colour, and sulphate of telluric oxide is formed. The red solution
probably contains a lower oxide of teUurium, which, on the addition of
water, is partly reduced to the metallic state by the sulphurous acid still
present, and is partly resolved into metallic tellurium and telluric oxide,
which remains in solution. (N. W. Fischer, Fogg, 12, 153; 15, 77; 16,
118.) The red solution, when preserved in close vessels, remains
unaltered for a long time ; when exposed to the air, it absorbs moisture
and becomes decolorized, the tellurium being converted into TeO*, at the
expense of the sulphuric acid : hence the liquid, when exposed to the air,
smells constantly of sulphurous acid. But the odour of sulphurous acid
is not perceived at the time of dissolving the metal in oil of vitriol ; con-
sequently, the red solution contains metallic tellurium in direct combina-
tion with sulphuric acid, corresponding to the solution of sulphur and
selenium in sulphuric acid. (Magnus, Fogg, 10, 491.) The theory of
Magnus is supported by the red colour of the solution, which agrees with
that of tellunde of potassium in water. (Berzelius.)
C. Sdlphatb of Telluric Oxide or Tbllubic Sulphate. — a. Baste
Sttlpfiate, — Formed by heating the dry salt, b, in a retort, till part of
the sulphuric acid is driven off; there then remains an easily fusiblci
vitreous residue, which is yellow while fused, and becomes transparent
and colourless on cooling; when more strongly heated in an open crucible^
it ffives off all its sulphuric acid, leaving fused telluric oxide, which
solidifies in an opaque crystalline mass. (Berzelius.)
b, BiaiUphcUe, — Pounded tellurium made into ^a thin paste with oil
of vitriol, yields, when heated, a purple-red mass, which, as soon as all
the liquid is driven off, evolves sulphurous acid and becomes colourless.
After the expulsion of the oil of vitriol, there remains a white, earthy
mass, having at first a drying and afterwards a metallic taste. When
heated to redness, it melts and leaves a residue, first of salt a and after-
wards of telluric oxide. Water resolves it into telluric oxide and dilute
sulphuric acid containing a very small quantity of oxide in solution.
It dissolves in warm hydrochloric or nitric acid, and, if the solution be
saturated, separates from it in grains on cooling. (Berselius.) — When
1 At. tellurium-powder is dissolved in 1 At. sulphuric acid diluted with
water, heat being applied and strong nitric acid added, a large Quantity
of anhydrous tellurous acid separates from it on cooling; and if the
liquid be poured off and the excess of nitric acid evaporated, pearly
scales of the bi-acid salt are obtained. (Berzelius.)
When tellurium is heated with excess of oil of vitriol, till the red
solution becomes decolorized by boiling, a salt which is easily soluble in
408 TELLURIUM,
Water, separates on cooling. The supernatant liquid slowly dissolves
telluriam, forming a red solution, and is slightly reddened, even after
some time, by the introduction of a rod of zmc. (Fischer.) — Tellurium
dissolres in oil of vitriol mixed with 2 or 3 parts of water and a small
quantity of nitric acid, forming a colourless liquid which is not deoom-*
posed by the addition of a larger quantity of water. (KUproth.)
TeliiUBium and Selenium.
Selenide OF Tellurium. — These two bodies may be fused together
in all proportions. They evolre heat in uniting, and form an iron*black
brittle mass, of crystalline fracture; this substance fuses to a thin liquid^
even below a red neat; boils at a higher temperature; evaporates unde-
composed out of contact of air; but when exposed to the air, readily
oxidises, and forms transparent drops, which appear to consist of tellurio
selenite. (Berzelius.)
Tellurium and Iodine.
Tellurium and iodine unite in all proportions.
A. Subiodide of Tellurium. — By heating the compound (, or by
fusing a large quantity of tellurium with a small quantity of iodine, a
metallic mass is obtained. (Berzelius.)
B. Proto-iodide of Tellurium. — TeUurotu Iodide^ lodotellurous
Acid, — ^Tel. — Formed by heating in a distilling apparatus a pounded
mixture of 1 At. tellurium, and rather more than 1 At. iodine, at a very
gentle heat. The excess of iodine passes off, and the proto-iodide of
tellurium sublimes in black, crystalline flakes, having some metallic
lustre, very fusible and volatile, and forming, after fusion, a mass which
has a non-crystalline fracture. — When suddenly heated, it gives off iodine
and is converted into A. — When digested in aqueous hydrochloric acid or
ammonia, it finally leaves a residue of metallic tellurium. It is not
attacked by water, even when boiling. (Berzelius.)
C. Biniodide of Tellurium. — Telluric Iodide, ledotelluric Add,"^
Formed when finely pounded hydrate of telluric oxide is digested in a
closed vessel for some time, with aqueous hydriodic acid. The telluric
oxide is then converted into coherent, iron-grey biniodide of tellurium.
A small quantity of this compound dissolves in the excess of hydriodic
acid, imparting to it a dark brown colour, and may be separated from it
in iron-grey prisms, by evaporation in vacuo over oil of vitriol and burnt
lime, whicli takes up the hydriodic acid and excess of iodine. When
tellurium-powder is digested for a considerable time with iodine and water,
the dark brown liquid poured off from the insoluble portion contains bat
a small quantity of biniodide of tellurium dissolved in excess of iodine;
on evaporation, it gives off iodine, becomes continually paler, and leaves
a black residue of biniodide of tellurium.
Fine, nearly black grains, or iron-grey prisms,
Tc 64 20-25
21 252 7975
Tel' 316 ZT! lOO'OO
TELLUEIUM AND IODINE. 40&
Biniodide of tellurimn fases when heated, and on boiling eyolres
iodine, pare at first, but becoming continually richer in tellurium, till
the compound A is left behind. — By water it is resolved into tellurite of
telluric iodide which retains the form of the telluric iodide, and aqueous
hjdriodic acid in which a small quantity of the telluric iodide dissolves.
(Berselius.) Cold water exerts but a slight decomposing action, and
remains colourless, taking up, however, a small poi-tion of hydriodio
acid ; boiling water acquires a dark brown colour ; after thorough boiling
with water, 100 parts of telluric iodide leave 23*5 parts of the tellurite
of that compound. The brown solution, when evaporated, evolves
hydriodic acid and iodine, leaving behind the dissolved biniodide.
(Berzelius.)
3TeP + 4HO = TcP,2T€0« + 4HL
Hence, 3 At. TeP (=948 parts) should give up | of its iodine as hydriodic
acid, and yield 1 At. TeP, 2TeO» (=376 parts); 948 : 376=100 : 39*66;
consequently, 100 parts of telluric iodide should yield 39'66 parts of the
tellurite; but as a small quantity of the biniodide dissolves in the aqueous
hydriodio acid, the quantity actually obtained is only 36*5 parts. — Binio-
dide of tellurium dissolves in alcohol, undergoing, however, some decom*
position, even when the alcohol is absolute. (Berzelius.)
Biniodide of tellurium combines with other metallic iodides, especially
with those of the alkali-metals. These compounds, which may be called
lodotellurates, are obtained by exactly saturating a solution of telluric
iodide in concentrated hydriodic acid with an alkali, or by mixing it
with an alkaline hydriodate and leaving the mixture to spontaneous eva-
poration. On the other hand, solid telluric iodide is but slightly soluble in
aqueous-alkaline hydriodates. Iron-grey, shining crystal, forming with
a small quantity of water, a brown solution which is but slightly preci-
pitated by a larger quantity of water.
D. Tellurite of Telluric Iodide. — Formed by boiling biniodide of
tellurium with successive quantities of water. Pale greyieh-brown, very
heavy. Fuses with difficulty when heated, yielding traces of water, then
iodine mixed with a very small quantity of tellurium, and lastly, at a
Strong red heat, a sublimate of metallic tellurium which collects in drops.
This compound is not decomposed by water. (Berzollus.)
E. Hydriodate op Telluric Iodide. — Concentrated hydriodic acid
saturated with biniodide of tellurium and evaporated in vacuo over oil of
vitriol and slaked lime, yields long, right-angled, four-sided prisms,
having the metallic lustre. These crystals, when sealed up in a ^lass
tube and heated by the hand, melt into a dark brown liquid, which
solidifies again on cooling. In an open vessel at 50° or 60°, they do not
fuse, but give off a brown fume of hydriodic acid decomposed by contact
with the air, and leave biniodide of tellurium having the form of the
crystals but a dull sur&ce and porous texture. Water decomposes the
crystals, yielding a precipitate of telluric iodide, together with dilute
hydriodic acid containing a small quantity of iodide of tellurium in
solution, which gives it a brown colour. (Berielius.)
F. Teriodidb op Tellurium or Hydriodate op Telluric Acid.—
Aqueous telluric acid forms with aqueous hydriodic acid, a mixture which
is clear and brown at first, even if the latter predominates. This com-
410 TBLLURIUM.
pound, when it evaporateer spontaoeooslj, deposiis tellorio iodide, while
the excess of tellaric acid ooUecta in coiuurleM prisms on tko edge of th«
yessel. Hence one-third of the iodine goes off on evaporation. When
telluric acid and hydriodic acid are mixed, in solutions saturated a«
completely as poissible, hiniodide of tellurium is immediately precipitated
in the form of a black ponder. (Berzelius.)
G. Periodidb of TELLUiiiUM.— Formed b^ melting iodine in a glaaa
tube, dropping in a piece of tellurium, shaking for a few seconds, and
decanting to separate the iodine saturated with tellurium, from the
tollurium which remains undissolved. Dissolves in water very slowly
and sparingly, but gives it a very dark brown colour. The solntioii
is decolorized by sulphite of ammonia, and, on the addition of hydro-
chloric acid, deposits metallic tellurium. (Berzelius.)
Tblluaium and Bromine.
Bromine and tellurium eombine at ordinary temperatores, the com-*
bination being attended with development of heat.
A. SuD-BBOMiDB OF TELLVRiUH.-^Bibromide of tellurium may be
fused with tellurium in any proportion.
B. pROTOBROMiDB OF TELLURIUM. — Telluroiu £ramide, Bromaiel*
lurous Acid. — TeBr. — When a mixture of bromine and telluiium, con-
taining an excess of the latter, is distilled, this compound passes over
in the form of • violet vapour which condenses in fine black crystaJline
needles; these crystals fuse readily; and, on cooling, solidify in a mass,
having a non-crystalline fracture and but little lustre. This compound
is decomposed by water. (Berzelius.)
C. BiBBOMiDB OF TELLURIUM.-— ^WZwric Bromide, BromateUuric
Acid. — To form this compound, bromine is introduced into a glass tube
sealed at one end and cooled by immersion in ice, pounded tellurium being
afterwards added, not in excess, and with frequent stirring ; the excess
of bromine is driven off by the heat of a water-bath. Eeddish yellow
mass, which, when gently heated, fuses to a dark red, transparent liquid,
and forms a crystalline solid on cooling; at a higher temperature, it is
converted into a yellow vapour, which sublimes, partly in the form of a
yellow meal, partly in pale-yellow crystalline needles.
Te 64-0 28-99
2Br 156-8 71-01
TeBr8 220'8 10000
HydraUd Bihromide of Tellurium, or BihydrohromaU of Telluric Oxide,
— Bibromide of tellurium very slowly absorbs moisture when exposed to
the air, and dissolves, without decomposition, in a small quantity of
water. The yellow solution evaporated to a syrupy consistence over oil
of vitriol, leaves dark ruby-red, rhombic tables, which, when more com-
pletely dried, give off their water and become yellow and earthy; they
deliquesce very quickly when exposed to the air. The yellow solution,
when mixed with a larger quantity of water, is resolved into precipitated
PROTOCHLORIDB OF TJSLLURIUxM. 411
tellurite of tellario bromide, aud colourless, dilate Hydrobro'mic acid oon^
taining a fimall quantity of telluric bromide in solution.
Bibromide of tellurium combines with tbe bromides of the alkali-metals,
forming compounds which may be called BromotelluraUs,
D. Tellurite op Telluric Bromide. — \^hen bibromide of tellurium
is decomposed by boiling water, and the liquid left to cool, a yellowish,
granular compound crystallizes out, which, when heated, gives off the
greater part of the telluric bromide, without intumescence, and after
cooling leaves a yellow, crystalliue mass. This mass, when ignited for
a very long time, is converted into pure tellnrons acid. The aqueous
solution of telluric bromide heated with water till its colour is destroyed,
and then evaporated over the water-bath, allows the hydrobromic acid to
escape with the last portions of water, and yields a non-deliquescent^
reddish-yellow varnish, which is rendered milk-white even by the smallest
Quantities of water. A larger quantity of water withdraws the bromine
irom the compound. (Berzelius.)
Tellurium and Chlobinb.
A. Subchloridb of Tellubium. — Protochloride of tellurium may be
fused with tellurium in all proportions. Such a mixture, when ignited in
a retort, first gives off protochloride of tellurium, then metallic drops of a
compound richer in tellurium, and leaves a residue which resembles
tellurium, but is more easily pulverized and reddens litmus; it most be
freed from the chlorine still adhering. to it, by fusion in an atmosphere of
hydrogen, or by boiling the powder with a small quantity of hydro-
chloric acid and afterwards with water. (Berzelius.)
B. Protochloride of Tellurium. — Tellurous Chloride, Chloro-
tellurous Acid. — 1 . Formed by passing a gentle stream of chlorine gas over
strongly heated tellurium or native telluride of silver,' and freeing the
distilled protochloride of tellurium from any bichloride that may be mixed
with it — the former being the more volatile. The separation may also
be effected, though less completely, by distillation over tellurium-powder.'
(H. Rose, Pogg, 21, 443.) — 2. By mixing bichloride of tellurium with an
equal weight of the metal, and collecting the protochloride by distillation.
(Berzelius.) Black, amorphous body, having an earthy fracture and yielding
a yellowish -green powder ; it fuses readily to a black liquid, and is more
volatile than C. Its vapour has the same colour as that of iodine, only
paler (H. Rose); it is purple, but if air be completely excluded tiom the
vessel, the colour somewhat inclines to yellow. (Berzelius.) It does not
fume in the air. (H. Rose.)
H.Rose.
Tc 64-0 .... fi4-38
CI 35-4 .... 35-62 37'04 .... 37-77
TcCl 99I Z 100-00 '
Attracts moisture from the air, and becomes surrounded with a drop
of transparent liquid, which is rendered milky on the addition of water :
with a larger quantity of water, a grey liquid is formed, tellnrousacid and
metallic tellurium being separated at the same time. When treated
with aqueous sulphuric or hydrochloric acid, which retain the tellurous
413 TELLURIUM.
acid iu aolution, it deposits notliiDg bat tellariam, in slender crystals^
amounting to 32*04 per cent. — consequently half the quantity contained
in the protochloride. (H. Rose.)
2TcCl + 2H0 + xS03 = Te + TeO«, 2HCI xSO».
A mixture of tellurium and tellurous acid is separated eyen by triturating
f protochloride of tellurium with quick-lime or dry carbonate of soda.
Berzelius.) Protochloride of tellurium combines with sal-ammoniac*
Protochloride and bichloride of tellurium may be fused together in
any proportion: if the former predominates^ the compound is black, and
opaque during fusion; if the latter is in excess, the compound is yellowish,
and dark- red while liquid. (Berzelius.)
C. Bichloride op Tellurium. — Telluric CIdoride, CMcroteUuric
Acid. — Tellurium bums in chlorine gas with a white light, and is con-*
yerted into white, easily fusible, and volatile telluric chloride. (H. Davy.)
Chlorine gas does not act on tellurium at ordinary temperatures ; but on
the application of a gentle heat, combination takes place attended with
combustion. The tellurium which still remains nncombmed dissolves in the
telluric chloride produced, and forms a black thick liquid which continues
to absorb chlorine, at the same time becoming transparent and deep red, and
ultimately deep yellow; on cooling, it acquires a lemon-yellow colour, and
then solidifies to a white mass. A yellow tint after solidification would
indicate the presence of protochloride. (Berzelius.) Bichloride of tellu-
rium is snow-white, of crystalline texture, and fuses readily to a yellow
liquid, which becomes deep red near the boiling point; boils at a stronger
heat without spirting, and is converted into a deep yellow vapour,
which, in dry air, condenses into a white, non-crystalline, mealy powder.
Tc
2Cl
64-0
70-8
47-47
..... 5^-53
TeCl2
134-8
100-00
The smallest quantity of organic matter causes the bichloride to turn
yellow on melting, converting, in fact, a portion of that compound into
protochloride, which then, at a higher temperature, escapes in violet
vapours. Bichloride of tellurium when exposed to the air, deliquesces
more rapidly than chloride of calcium, and is thereby converted into a
thin liquid, which gradually turns milky, gives ofi* hydrochloric acid, and
dries up to a white residue, consisting of tellurite of telluric chloride.
With boiling water it forms a clear solution, which, when slowly cooled,
deposits crystals of tellurous acid mixed with smaller crystals of tellurite
of telluric chloride. Combines with the chlorides of the alkali-metals,
forming compounds which may be called Chlorotellurates,
D. Tellurite op Telluric Chloride. — Banc Telluric Chloride. —
a. Separates in the decomposition of telluric chloride by cold water. The
whole of the chloride of tellurium may be separated by repeated washing,
pure tellurous acid being left behind.--^. Crystallizes out from its solution
in boiling water, together with tellurous acid. The crystals, when heated,
evolve bichloride of tellurium, with strong decrepitation and intumes-
cence; afterwards yield a small quantity of white sublimate, likewise
consisting of tellurite of telluric chloride; and leave tellurous acid, which
still contains telluric chloride, even after long ignition, and is therefore
TELLURIUM AND NITIiOGEN. 413
traneparent when solidified, and fuses mnch mo^ easily tban pure tella-*
rous acid. — c. Remains behind when bichloride of telluriam is exposed to
the air till it has deliquesced and dried up again.-— i^. When a solution
of tellnrous acid is evaporated over the water-bath, there remains a pale
yellow, transparent residue, which deliquesces ivery slowly, and at the
same time becomes milk-white. (Berzel ins.)— These compounds, a....c,
contain tellurous acid and bichloride of tellurium in yarious proportions.
The calculations of their composition (Pogg, 32, 612-613), require
rovision, TeCl appearing therein instead of TeCP.
E. Hydrociiloratb op Telluric Chloride, or Acid HTDRocnLO^
HATE OP Telluric Oxide. — 1. Formed by dissolving telluric chloride,
or telluric oxide, in hj'drochloric acid. — 2. By dissolving tellurium in
aqua-regia. — The deep yellow solution, evaporated over the water^bath,
leaves tellurite of telluric chloride, (yid, sup,) (Berzelius.) — If the solu-
tion does not contain a great excess of hydrochloric acid, the addition of
water throws down tellurite of telluric chloride; an excess of water
dissolves the precipitate (according to Fischer), only when the solution
contains a coosiderable quantity of hydrochloric acid.
F. Hydroohlorate op Telluric Acid.— When a solution of tel-
luric acid in strong hydrocMoric acid is left to evaporate spontaneously,
it gives off all its hydrochloric acid, and leaves pure telluric acid.
(Berzelius.)
Tellurium and Fluorine.
A. BiFLUORiDE OF TELLURIUM. — Ttlluric Fluortde. — Sublimes on
heating the compound B. — Transparent ; solid at ordinary temperatures ;
soft or semifluid when, heated; deliquesces very quickly in the air;
deposits tellurous acid on the addition of a larger quantity of water.
B. Tellurite op Telluric Fluoride. — a. A solution of tellnrous
acid in aqueous hydrofluoric acid evaporated over the water-bath, yields
a transparent and colourless syrup, which, on cooling, solidifies to a milk-
white mass, consisting of little warty granules. When this mass is
heated in a platinum crucible, over the mouth of which is placed a larger
vessel of the same kind surrounded with water and ice, it melts, gives
off water and afterwards hydrofluoric acid, and ultimately yields a
Hublimate of telluric fluoride. — 6. After the mass has been heated to
redness, there remains a compound of the same kind, richer in tellurous
acid; tliis compound solidifies to a cirstalline-granular mass, gives up*
hydrofluoric acid to boiling water, and evolves that acid when treatea
with oil of vitriol. (Berzelius.)
Tellurium and Nitroosn.
A. Nitrate of Telluric Oxide or Telluric Nitrate. — The
metal dissolves easily in nitric acid, forming a colourless solution which
is not decomposed by dilution with water. (Klaproth.) Water added to
the solution precipitates the hydrate of tellurous acid in white flakes.—*
The solution, if left to itself at ordinary temperatures, or warmed for a
414 TBLLURIUM.
qnarier of an hoar, depotita aohjdrons tellnroiui aeid in cfystalline mina,
so that the solation retains bnt a fioiall quantity of tellnriam, and is no
longer decomposed by water. — When the eolation is evaporated to diy-
ness over the water-bath, there remains pare anhydroas teUuric oxide^
whichy at higher temperatares^ i^ves off only ^ IP^T cent, more of oxygen.
If the solution be left to itself for a while, the whole of the tellnric
oxide is deposited in the anhydrous insoluble state, and is then no longer
preclpitable by water. (Berzelins.)
B. Bi-HTDROTELLURATE OF Ammonia. — ^Ammoniacal gas mixed with
hydrotelluric acid gas in excess, condenses in white crystalline laminsdy
which at 80^ are converted into a vapour whose density is 1*32. (Binean,
Ann. Ckim, Phyn. 67, 231 ; 68, 438.) — [There appears to be an error in
Bineau's calculation of the vapour-density.]
C. Tellurite op Ammonia. — a. Manotdluritef-^The anhydrous
acid dissolves very slowly in aqueous ammonia, the hydrated acid almost
instantly. The monobasic salt cannot be obtained in the solid state from
the solution ; on evaporating the solution at a gentle heat, it gives off
ammonia and leaves white crystalline grains containing 92*40 tellurons
acid, 719 water, and 0*41 ammonia. Sal-ammoniac gives with the solu-
tion, a flocculent precipitate which appears ^ consist of the salt b (it is
soluble in excess of ammonia, and does not reappear on the addition of
sal-ammoniac); after washing with alcohol, it is no longer soluble in
water.
b, Quadrotellurite, — 1. If a solution of hydrated tellurons acid or
bichloride of tellurium in warm aqueous carbonate of ammonia, be
mixed while still warm with a email quantity of sal-ammoniac, a white,
opaque, heavy, granular precipitate is slowly deposited. — 2. Hereupon
the addition of alcohol precipitates a further portion of the same salt.*—
When heated, it is resolved into ammonia, water, and tellurons acid.
Berzelius.
Bried at 60*. ' T iT^
NH» 17 .... 4-45
4TeO« 320 .... 83-77 83-1 .... 83-87
5HQ 45 .... 11-78
NH*0,4Te02 + 4Aq. 382 .... 100-00
D. Tellurate op Ammonia. — a, Monotellurate, — Cold aqueous
ammonia forms with pulverized telluric acid, a white glutinous magma,
which dissolves on boiling; the solution becomes turbid on cooling, but
ffradually resumes its transparency, and deposits white flakes and grannies,
rart of that which remains in solution may be precipitated by sal-ammo-
niac, and the rest by alcohol. The precipitate is washed with alcohol,
which, however, exerts a slight solvent action as soon as the sal-
ammoniac is washed away. — 2. If a mixture of monotellurate of potash,
sal-ammoniac, and a small quantity of ammonia, be dissolved in boiling
water, and the solution left to cool, monotellurate of ammonia separates
from it in the form of a crystalline crust. — The salt prepared by
method (1) is white, and almost earthy after drying; it dissolves slowly,
but completely, in cold water, quickly in boiling water. (Berzelius.)
b. BitelluraU, — Formed by precipitating a saturated solution of
bitellurate of soda with sal-ammoniac. The solution of bitellurate of
TELLURIUM AND NITROGEN. 416
potaih gives no precipitate^ because it is less soluble in water.-^The ure-
cipitate adheres to the glass in the form of a glutinous mass. It dissolves
with difficulty in water. When boiled with water in open vessels, it
gives off ammonia. If heated with water in close vessels, it partly
melts to a white mass which solidifies on cooling, and partly dissolves
in the water, separating in fine grains as the liquid cools. (Berzelius.)
c. QuadrotellurcUe, — 1. By precipitating the solution of quadrotellu-
rate of soda with ammonia. The addition of alcohol greatly increases
the quantity of the precipitate, which may then be washed with alcohol.
The salt is flocculent ; when heated, it fuses imperfectly^ swells up, and
gives off water. It is but slightly soluble in water. — 2. When a solu-
tion of monotellurate of ammonia is left to evaporate, either sponta-
neously or with the aid of a gentle heat, the quadrotellurate remains in
the form of a gummy film, which becomes milk-white when moistened
with water, — dissolves sparingly in cold, more abundantly in boiling
water, the solution not yielding any deposit on cooling, — and turns yellow
when carefully heated. (Berzelias.)
E. SuLPBtoTELLTTRirfs OP Ammoniitm. — 3NH*S, TcS^ — An aqueous
solution of tellurite of ammonia, saturated with hydrosulphuric acid
gas and evaporated in vacno over potash, yields pale-yellow, four-sided
prisms, which give off hydrosulphate of ammonia when exposed to the
air. Even in vacno, the solution gives off hydrosulphate of ammonia, till
the whole space is saturated with its vapour. (Berzelins.)
In Berzelius's Lehrhuch^ this salt, as well as those which correspond
to it, is designated and described as if it contained not Te 8' but TeS' j
this, however, is contrary to the original memoir (Pogg, 8, 411), and even
to Berselius's Lehrbttch itself (4, 58 and 59).
F. loDOTELLURATB OP Ammonium. — A compouud of Siniodide of
Tellurium with Iodide of Ammonium, — The solution of biniodide of
tellurium in aqueous hydriodic acid, on being saturated with ammonia
and left to spontaneous evaporation, yields steel-grey, (often hemitropic)
octohedrons and segments of octohedrons, soluble in water and in
absolute aloohoL (Berzelius.)
G. Ghlorotellurite op Ammonium. — ProtocMoride of Tellurium
vnth Chloride of Ammonium. — Formed by subliming a mixture of sal-
ammoniac and a tellurite of a fixed alkali. Ammonia and water [and
nitrogen 1] are first evolved, and afterwards a black sublimate is formed,
having a yellowish radiated fracture, and yielding a greenish-yellow
powder. The sublimate, when a very small quantity of water is poured
upon it, turns white at first from separation of tellurous acid; this acid
then dissolves completely, especially if heat be applied, and leaves
metallic tellurium, still exhibiting the radiated texture of the sublimate.
A larger quantity of water throws down a mixture of metallic tellurium
and tellurous acid, which may be separated by hydrochloric acid : the
water holds in solution the following salt, together with free sal-ammo-
niac. (Berzelias.)
H. Chlorotelluratb op AMMONitTM. — Bichloride of Tellurium with
Chloride of Ammonium. — The aqueous solution of bichloride of tellu-
rium mixed with sal-ammoniac, yields lemon-yellow, often hemitropic
octohedrons and octohedral segments, which dissolve in a small quantity
416 TELLURIUM.
of water witliout decomposing, and fonn a colourless liquid, but aM
decomposed by a larger quantity of water, and by absolute alcobol,
(Berzelins.)
Tellurium and Potassium.
A. Telluridb of Potassium. — 1. When tellurium conducts tbe
negative electricity of a thousand-pair voltaic battery into hydrate of
potash, great heat is evolved, and the tellurium combines with the sepa-
rated potassium, forming telluride of potassium. — 2. Tellurium, heated
with potassium in a retort filled with hydrogen gas, combines with the
potassium, producing the most vivid combustion. — 3. Ten parts of
telluric oxide, 2 hydrate of potash, and 1 charcoal, heated in a glass
retort to a temperature somewhat below redness, form telluride of potas-
sium, the action being attended with combustion and evolution of car-
bonic acid. — The alloy obtained by heating telluric oxide containing
potash, with charcoal (it contains a smaller quantity of potassium than
others), is steel -grey, brittle, and fuses much more easily than pure
tellurium. The telluride of potassium obtained by method (1) has the
colour of nickel ; that obtained by (2) is dark copper-coloured, brittle,
has a crystalline fracture, and does not melt below a red heat.
AqueoM Telluride of Potassium or Hydrotellurate of Potash, — Telln-
ride of potassium dissolves in water, forming a purple solution; that
which is prepared by method (I), and that obtained by fusing the two
metals together in equal portions, dissolve without evolution of hydrogen.
The solution, when exposed to the air, becomes decolorized, and deposits
the whole of the tellurium in thin metal-shining scales; when treated
with acids, it evolves hydrotelluric acid gas. (H. Davy.) — Tellurium
dissolves in a boiling and highly concentrated solution of potash, forming
tellurite and hydrotellurate of potash (or telluride of potassium). But
the purple-red solution, both on cooling and on dilution with water,
deposits the whole of the tellurium in the form of a grey metallic
powder. — Similarly, tellurium-powder heated with dry carbonate of pot-
ash, drives out the carbonic .acid and forms telluride of potassium and
tolluratc of potash; but water takes up the caustic alkali, and separates
the whole of the tellurium.
B. Tellurite op Potash. — a, MonotelluriU, — 1 At. tellurous acid,
fused with an excess of carbonate of potash, drives out 1 At. carbonic
acid. — 1 At. tellurous acid, slowly heated with 1 At. carbonate of potash,
fuses when the heat rises to redness, and on cooling, solidifies in a white
mass, consisting of rather large crystals, and exhibiting planes of
cleavage. It has an alkaline reaction and caustic taste. Dissolves
slowly in cold, more quickly in warm water; the solution evaporated
over oil of vitriol in air free from carbonic acid, becomes syrupy, and
afterwards solidifies in a granular, non-deliquescent mass. (Berzelins.)
6. Bitellurite, — Formed even by boiling tellurous acid with aqueous
solulion of carbonate of potash. — rrepared by heating 2 At. tellurous
acid with 1 At. carbonate of potash. The compound fuses somewhat
below a red heat, and forms a yellow liquid, which, on cooling, solidifies to
a colourless, translucent, distinctly crystalline mass. This mass is resolved
by cold water into monotellurite which dissolves, and quadrotellurite
which remains undissolved. Boiling water dissolves it completely, but
on cooling deposits grains of quadrotellurite; but if it be dissolved in
TELLURATE OF POTASH.
417
hoi water^ which already holds in solution a large qnantitj of the mono<-
tellarite^ the liquid^ when eyaporated in the water-hath, deposits the
hitellurite in the form of a hsxa crystalline crust. (Berzelius.)
e. QuadroteUuriie,*^¥ormed hy hoiling fused and pounded tellurons
acid for some time with solution of carbonate of potash, filtering at a
boiling heat, and leaving the solution to cool. As the liquid cools, the
greater part of the salt crystallises out. The mother-liquid 3rields an
additional quantity on evaporation and cooling. Monotellurite of potash
remains in solution. — The quadrotellurite fonns pearly grains, which,
imder the microscope, appear to be formed of regular six-sided prisms
and tables. — Cold water decomposes the crystals, extracting monotel-
lurite and hitellurite of potash, and leaving a swollen, gelatinous hydrate
of tellurons acid, still retaining the form of the crystals. Boiling water
dissolves out hitellurite of potash, and leaves a heavy powder, consisting
of anhydrous tellurous acid (which retains, at most, -^ per cent, of the
salt) ; the solution, on cooling, deposits quadrotellurite of potash. The
crystals, when heated, give off their water with strong intumescence,
and the dehydrated salt fuses at a low red heat, forming a yellow liquid,
which, on cooling, yields a transparent and odourless glass. This glass,
when pulverized, behaves with boiling water in the same manner as the
crystals. (Benelins.)
IfftHied.
Crystallized,
Berzelius
KO
47-2 .... 12-85
KO
47'2 .... 11-71
.... 11-83
4TcO«
.. 3200 .... 8715
4TcO-....
3200 .... 79-36
.... 79-02
4HO ....
36-0 .... 8-93
915
KO,4TeO« 367-2 .... 10000
-l-4Aq. 403-2
100-00
10000
C. Telluratb of Potass. — a. Monotellurate, — Formed by boiling
1 At. telluric acid with 1 At. carbonate of potash and with water, till
the whole is evaporated to dryness. — 2. When crystallized telluric acid
in the state of powder, or its concentrated aqueous solution, is super-
saturated with caustic potash, monotellurate of potash, which is but
slightly soluble in water containing potash, separates from the liquid in
the form of a soft, glutinous coagulum : this substance dissolves on tl»e
application of a moderate heat, and if the solution be then cooled
gradually down to 0^, the salt crystallizes out from it so completely,
provided the potash- ley is not too dilute, that the mother-liquid scarcely
becomes turbid on the addition of alcohol. The crystals are washed with
alcohol. If the potash-ley is weak, the salt does not sepajute till
alcohol is added; if the alcohol be added in moderate quantity and by small
portions at a time, the salt separates in oily drops, which are afterwards
converted into a mass of crystals ; a larger quantity of alcohol causes
the salt to separate in crystalline grains. — This salt is likewise formed on
heating tellurous acid with nitre to scarcely visible redness, till quadro-
tellurate of potash is formed, and then adding small portions of bicar-
bonate of potash as long as effervescence is produced ; it is, however,
mixed with nitrite and nitrate of potash, and likewise with tellurite of
potash, the quantity of the latter increasing with the heat applied to
produce the reaction.
Tellurate of potash prepared by method (2) crystallizes in obliquely
truncated, three-sided needles united in tufts. The aqueous solution of
the salt obtained by the first method yields a crystalline crust, when
evaporated in vacuo oye^ oil 9f yitriQl. On evaporating the solution at a
you ir. 2 b
i-.
418 TELLURIUM.
moderate heat, the talt remainfl in the form of a tnuuliicent, gmninT,
fissured mass. The crystals, when heated, gire off trater and bake
together in a white mass. When exposed to the air, the)r become moifit
without deliqoescing, and are converted into a mixture of bitellnrate and
carbonate of potash. The salt is soluble in water, but not in alcohoL
A small quantity of one of the stronger acids added to the solution,
throws down the salt 5 ; a quantity jnst sufficient to give the liquid an
alkaline reaction precipitates the salt c; a still larger quantity withdraws
the whole of the potasn, and renders the liquid clear. But if the acid
added be the aoetu^ and the clear mixture be evaporated to dryness and
the residue dried at a temperature between 80° and 100^ the tellnric
acid again takes up the half of the potash, so that a mixture of acetate
and bitellnrate of potash is ultimately formedr (Berzelius.)
Anhydrous^ CrpfUUUi^d, BcndinS*
KO 47-2 .... 34-91 KO 47-2 .... 26-191 .-.^,
TcO> 880 .... 6509 TcO^ .... 88-0 .... 48-83/ ^^ ^
5HO .... 450 .... 24-98 23 75
KO,TeO>.... 135-2 .... 100-00 +5Aq! 180*2 .... 100-00 100-00
t, Biiellurate, — ^This salt is formed: 1. When hydrated tellnrieacid
is brought in contact with solation of carbonate of potash. — 2. It is,
however, produced with greater certainty by dissolving 2 At. hydrated
telluric acid and 1 At. carbonate of potasn in a ftmall quantity of boiling
water, and leaving the solation to cool. As thus obtained, it forms a
woolly deposit, which becomes white and earthy on drying ; the mother-
liqui<I, when evaporated, yields an additional quantity of salt having a
crystalline aspect. — 3. The solution of monoteUurate of potash exposed
to the air in covered vessels deposits bitellurate in hard crystalline
grains. — 4. By mixing the aqueous solution of the salt a with excess of
acetic acid, eraporating to dryness, and dissolving out the acetate of
potash with alcohol of specific gravity 0*85. — 5. By fusing t^llurate of
potash with nitre till the whole is reduced to a clear liquid; digesting the
mass, when cold, in boiling water, to extract the nitrate and nitrite of
"potash contained in it; ana dissolving the residual bitellnrate of potash-—
which is soluble in pure boiling water, but not in water containing nitrate
of potash — in a fresh quantity of boiling water : from this solution the salt
is deposited on cooling. The higher the temperature at which the
mixture is fused, the greater is the quantity of tellurite of potash
mixed with the tellurate. This process sometimes yields a modification
of the salt, which is insoluble in ooiling water or in acids or alkalis, is
white when cold, turns yellow when heated, then fuses, gives off oxygen
with effervescence, and leaves bitellurite of potash.
The hydrated salt which crystallizes from a hot solution on cooling, is
partly woolly, partly granular. On evaporating the aqueous solution
over the water-bath, it remains in the form of a white substance, gummy
at the edges. It has an alkaline reaction, and a metallic and slightly
alkaline taste. When heated, it gives off water, turns yellow, and at a
higher temperature, but still below redness, fuses into a mixture of mono*
tellurate and insoluble quadrotellurate of potajsh; the former may be
extracted by water t
3(K0, 2TeOa) « 2(KO,TcO») + KO,4TeO«.
The bitellnrate dissolves sparingly in cold water, much mor€| abundftQtly
in hot water.
tellurAtb op potash. 419
Ankyir&¥i. CryMtmUUed. Btftdioa.
KO 47-2 ... 21-15 KO 47*2 .... 1821 1 q^..
2TcO» 1760 .... 78-85 2TeO».... 1760 ,.^ 67-90/ *"" *
4HO .... 360 .... 13-89 13-9
KO,2TeO» 223-2 .... 10000 +4Aq. 2592 .... 10000 1000
c. QitadrotelturaCe,''-^, Containing the soluble modification of Telluric
Acid. — 1. CrystallizeB from a solution of 4 At. telluric acid and 1 At.
carbonate of potash in boiling water^ in a similar manner to the salt 5. —
2. Falls down on adding nitric acid to an aeneous solution of the mono-*
tellnrate as long as a precipitate is formed. — 8, Tellurous acid is fused
with nitre at a heat not higher than commencing redness; the mass
dissolved in water; the liquid mixed with a quantity of nitric aoid suffi-
cient to give it a slight alkaline reaction^ and then left for some hours in
contact with the precipitate; and lastly the precipitate is washed on the
filter with cold water^ care being taken not to use too much. — White,
loosely coherent salt. Loses the greater part (7*5 per cent.) of its water
at a gentle heat^ but retains a small portion (0*15 per cent.) till it turns
yellow and is converted into the following salt fi: afterwards, when more
strongly ignited in the platinum crucible, it gradually gives off 7*71 per
cent, of oxygen, and leaves 84*64 per cent, of tellurite of potash. The
salt is slightly soluble in water. When it is made to crystallize from its
aqueous solution by repeated evaporation and cooling, the crystals are
found to be mixed with bitellurate of potash and the mother-liquid
contains free telluric acid : if the water likewise contains other salts in
solution, this decomposition does not take place. (Berzelius.)
Anhydrous, CrysiatHzed, BcReHus*
KO 47-2 .... 11-82 KO 472 .... 10-84) -w,.„
4TeO» 352-0 .... 8818 4TeO».... 3520 .... 80-881 ^^ ^^
4HO .... 36'0 .... 8«28 765
KO,4TeO' 399-2 .... 10000 +4Aq. 435-2 .... 10000 10000
When this salt is prepared by method (1), the solution evaporated to
dryness over the water-bath, and the residue treated with water, part of
the salt remains behind in the form of a white powder, perfectly insoluble
in water but soluble in acids. It has, however, the same composition, but
retains the water more tenaciously, and does not part with it till raised
to a high temperature, at which it is converted into the following salt.
(Berzelius.)
/3. Quadrotellurate of Potash containing the imoluhle acid, — 1. Formed
by igniting the soluble quadrotellurate. — 2. When tellurous acid is very
gently ignited with chlorate of potash (whereupon oxygen and chlorine
gases are given off) and the chloride of potassium and chlorate of potash,
together with a small portion of bitellurate of potash produced at the
same time, are dissolved out by water, the yellow salt /3 remains behind.
— 3. Chlorine gas does not act upon cold tellnrite of potash; but if the
salt be wanned, it absorbs the gas and is converted into a substance of
darker colour; and on treating the yellow saline mass with water, after
cooling, the yellow salt remains undissolved. — 4. The yellow salt is likewise
produced on heating the hydrate of telluric acid with chloride of potassium,
nitre, and other potash^salts, the heat being kept much below redness.
Yellow powder, insoluble at ordinary temperatures in water, and in aqueous
sulphuric, nitric, or hydrochloric acid, and also in caustic potash. It dis-
solves slowly in boiling nitric acid, but more quickly in fused hydrate of
2b2
420 TELLURIUM.
potasb, the teUarie aeid then passing from the insoluble to the soluble
state. Anhydrous telluric acid boiled with moderately concentrated
solution of potash, does not dissolve hot takes up a small quantity of the
alkali. (Berzelius.)
D. SoLPfioTKLLVRlTB OF PoTAfisiUM. — Separates from a dilute solntion
evaporated in vacuo or from a concentrated solution evaporated in the
air at 40% in pale-yellow, four-sided prisms, easily melting to a black
liquid, which, on cooling, solidifies to a brownieh-vellow mass, soluble
again in water. In damp air, it becomes moist and soon blackens from
decomposition; the dilute solution likewise decomposes quickly in the
air. (Berzelius.)
E. loDOTBLLURATE OP PoTASSiUM. — Biuiodide oj TdluTium tfftik
Iodide of Fotamum. — Formed when a solution of biniodide of tellurium
. in concentrated hydriodic acid is exactly saturated with potash, or mixed
with iodide of potassium, and left to evaporate spontaneously. Steel-grey
prisms and rhombic tables having a strong metallic lustre ; they are easily
soluble in water, and form a brown solution, which, when a large quantity
of water is added to it, becomes turbid and yields a slight precipitate.
(Berzelius.)
F. BROMOTELLtTRATE OF PoTASSiUM. — Bfhrcmxde of Tellurium unik
Bromide of Potasnum. — Formed by mixing an aqueous solution of
bibromide of tellurium with chloride of potassium, and setting the liquid
aside to crystallize. Bichloride and bibromide of tellurium remain in the
solution. Cinnabar-red, short rhombic prisms or large rhombic tables,
frequently hemitropic with a re-entering angle. Permanent in the air.
Decomposed by a large quantity of water and likewise by alcohoL
(Berzelius.)
G. Chlorotellurate of Potabstvm. — Bichfjoride of Tellurium with
Chloride of Po^aMttfm.^Formed by dissolving chloride of potassium in %
solution of tellurous acid in hydrochloric acid, and leaving the liquid to
evaporate spontaneously. Colourless chloride of potassium crystallizes
out first : afterwards, when the liquid is reduced to a syrupy consistence,
the double salt separates: it must be dried between folds of bibulous
paper. Lemon- yellow crystals which are permanent in a diy winter
atmosphere, but deliquesce in the air in its ordinary state; they are
decomposible by water and by absolute alcohol. (Berzelius.)
Tellurium and Sodium.
A. Telluride of Sodium. — Behaves like telluride of potassium.
B. Tellurite op Soda. — a. Monotellurite. — 1 At. tellurous acid
heated with 1 At. carbonate of soda fuses at a full red heat, and forms a
mass, which, as it cools, but while still red hot, solidifies in large regular
crystals; if it be rapidly cooled, it swells up in vegetations. Dissolves
slowly but completely m cold water, and more quickly in warm water,
from which it does not separate on cooling. Alcohol throws down from
the solution a concentrated liquid, which, after a few days, yields large
crystals of the hydrated salt. The solution evaporated in vacuo over oil
of vitriol, leaves a white earthy mass. (Berzelius.)
5. BUeUurite. — Formed by fusing 2 At. tellurous acid with 1 At.
carbonate of soda. Fuses readily and crystallizes on cooling, but less
TBLLURATB OF SODA. 421
distinotly than the salt a. Decomposed by water in the same maimer as
the potash-salt (Berzelius.)
€, Quadrotellurite, — Separates from the boiline hot aqaeoos solution
of the Bsdt b, on slow cooling, in pearly scales and thin six-sided tables.
Behaves like the potash-salt, but swells up more strongly when heated,
and yields a transparent and colourless glass. (Berselius.)
AnhydrwM. CrysialUzed. Berzelius.
NaO 31-2 .... 8-88 NaO 312 .... 788 ........ 8*32
4TeO» 320-0 .... 91-12 4TeO* .... 3200 .... 80-77 80-46
5H0 450 .... 11-35 1122
NaO,4TeO* 3512 .... 10000 +5Aq 396*2 .... lOO'OO 10000
Before the blowpipe, tellurous acid forms with carbonate of soda on
platinum, a transparent and colourless glass, which becomes white on
cooling, and is easily reduced on charcoal. (Berzeliu«.)
C. Tblluratb op Soda. — Tellurous acid behaves with nitrate of
soda when fused with it, in the same manner as with nitrate of potash
(pp. 417....419). — a. If(motellur(Ue,^^^The hydrated salt separates from the
Wution of hydrated telluric acid in excess of warm soda-ley, partly on
cooling, partly on the addition of alcohol, either in grains or in the form
of a crystalline crust. It is also obtained by dissolving 1 At. hydrated
telluric acid and 1 At. carbonate of soda in water, and evaporating to
complete dryness at a temperature below 100^: it is only by evaporating
to dryness that the carbonic acid can be completely driven out. The
crystals do not part with all their water till they are heated nearly to
redness. They are but sparingly soluble either in cold or in hot water:
from the latter solution they do not separate on cooling. On adding an
excess of soda, however, the salt is deposited in grains. The aqueous
solution evaporated over the water-bath leaves at first a soft, gummy mass
easily soluble in water, but after complete drying it again leaves a
difficultly soluble compound. (Berzelius.) The salt dehydrated by heating
to a temperature short of redness, remains white even when hot, and
dissolves in heated dilute nitric acid, but not in water either hot or cold,
in which on the contrary it diffuses itself and produces milkiness.
Amhydroui. CryttalUxed, Berzelius.
NaO 31-2 .... 26-18 NaO .... 31-2 .... 22-741 «^.a
TeO* 88-0 .... 73-82 TcO* .... 88*0 .... 64-14/ ^^ ^
2HO .... 18-0 .... 13-12 13-1
NaO,TeO» 119-2 .... lOO'OO +2Aq! 1372 .... 10000 1000
5. BUeUurafe, — 1. Prepared by dissolving hydrate of telluric acid in
boiling carbonate of soda, and adding acetic acid after cooling, — where-
upon the bitellurate, which is at first precipitated, is decomposed by the
excess of acetic acid and redissolved. The clear mixture, on being evapo-
rated to dryness and heated till no more acetic acid is given off, leaves
a mixture of acetate and bitellurate of soda, the first of which may be
extracted by alcohol. The bitellurate of soda remains in the form of a
white powc^r, containing 14 per cent. (4 At.) of water, and slowly but
completely soluble in water. The solution, when left to spontaneous eva^
poration, dries up to a fissured gummy mass, which, when heated, becomes
milk-white and detaches itself from the glass; it dissolves completely,
though venr slowly, in water. The salt, when heated till deprived of
its water, is converted into a yellow mixture of quadrotellura^e and
41^2 TfiLLyRIUM.
monotellarate of wmIa^ the former of which is insoluble, while the lattto
may be extracted by continued washing with water. The same salt is
obtained by dissolving 2 At. hydrated telluric acid and 1 At carbonate of
soda in water. If an additional atom of carbonate of soda be added to this
solution, no monotellarate of soda is formed — but, on eTa|K>rating the
liquid at a gentle heat^ clear, syrupy drops of the bitellurate are deposited,
and the supernatant liquid is found to contain carbonate of soda. (Berzelius.)
€. Quadrotellurate,'"'^. Containing the Bolnble aeid, — An aqueous
solution of 4 At. hydrated telluric acid and 1 At. carbonate of soda
leaves, when spontaneously evaporated, a clear, somewhat fissured, but
still soft gum, which, when gently heated, dries up to a milk-white mass
adhering firmly to the glass vessel. This mass dissolves slowly in cold
water, leaving a white powder; and if the solution be evaporated to
dryness, the residue when treated with cold water again leaves a white
powder, and so on.
This white powder contains the same quantity of water as the soluble
salt, but, like the corresponding modifioation of the potash-salt, it is
insoluble even in boiling water. (Bercelius.)
fi. Containing ike insoluble acid. — Both the soluble quadrotellurate
and the white powder obtained by gently heating it, are converted by a
fltronger heat into the anhydrous, yellow, insoluble salt. (Beriellus.)
D. With Borax or Microcotmic salt, tellurous acid yields on platinum
a transparent and colourless glass which, when heated on charcoal, becomes
grey and turbid from reduction of tellurium. (Berzelius.)
E. SuLPHOTBLiiURiTE OP SoDRTM. — 3NaS,TeS*. — Formed by satu-
rating an aqueous solution of tellurite of soda with hydrosulphuric acid
gas, filtering from the precipitated sulphide of tellurium, and evaporating
the filtrate m vacuo. There remains a non-crystalline, pale-yellow mass,
which is easily decomposed by exposure to the air, and, when analysed by
hydrochloric acid, yields 40*5 parts of chloride of sodium for every 22 parts
of bisulphide of teflurium. (Berzelius.)
F. loDOTELLURATE OF SoDiUM. — Ciystallizes with difficulty from the
aqueous solution on evaporation. The crystals are brown without metallie
lustre; contain water of crystallization; deliquesce in moist air, and are
very easily soluble in water and alcohol. (Berzelius.)
G. Fluo-tellurate op Sodium. — Bifluoride of Tellurium with Fluo-
ride of Sodium, — Ill-defined crystals, decomposible by cold water^ soluble
in a very small quantity of boiling water. (Berzelius.)
Tellurium and Lithium.
A. Tellurite of Lithia. — a. Monotellurite.'^Tlie muss obtained by
fusing tellurous acid with carbonate of lithia in equivalent proportions,
crystallizes when slowly cooled, but swells up like the soda-salt if cooled
rapidly. The aqueous solution placed over oil of vitriol dries up to a
white, earthy, scarcely crystalline mass. (Berzelius.) — b. Bttdlurite.'-^
Easily fusible ; crystallizes on cooling. Decomposed by cold water into
monotellurate and quadrotellurate. Dissolves in boihng water, which,
however, likewise deposits the quadrotellurite. — c. Quadrotellurite. — >
Milk-white grains; behaves like the corresponding potash and soda salts
when fused or when treated with water. (Berzelius.)
TELLURATB OP BARYTA. 428
B. TbIiIiUEATE of LiTaiA.-*-a. and 6. ManoielluraU and JBUellurate.
—The aqueous flolution of either of these salts yields, on evaporation, a
transparent gunii which, when perfectly dried by heat, beccnnes milk-
white and sticks to the glass.— «. QuadroUUurate. — Exhibits precisely
similar characters. If heated to 100'' after dnring, it yields a whit^
insoluble powder, similar to that produced from the potash and soda salts,
and, at a stronger heat, gives off water, and is converted into the yellow
compound. (Bmelins.)
tk SuLrHonaxuBiTB ov Linnux.-*The eolntion dries up in vacuo
to a pale yellow, amorphous, saline mass, whMi deoomposes very easily
when exposed to the air. (Berzelius.)
Tellubiitm and Bariuh.
A. Tellurite op Baryta.— a. Monotellurite.'^l . When 1 At. tel-
lurous add is heated to redness with 1 At. carbonate of baryta^ the wliole
of the carbonic acid is driven off, and a yellow liquid formed, which, on
cooling, solidifies in a mass of colourless crystals. — 2. By double decom*
position, hydrated, white, voluminous flakes are obtained. Both the anhy-
drous and the hydrated salt are but very slightly soluble in water. The
solution has an alkaline reaction, and, when exposed to the air, deposits
carbonate and quadrotellurite of baryta. rBerzeliua.)
b, QuadroiAlurUe, — 1. When 4 At. tellurous acid and 1 At. carbonate
of baryta are heated together to low redness, the mixture fuses, and yields
a transparent and colourless glass on cooling.'^2. Very weak nitric acid
added to the aqueous solution of monetellnrite of baryta throws down veiy
bulky flakes. These flakes dissolve when acted upon by warm nitric acid
in excess; the solution, when evaporated, deposits no tellurous acid till
the nitric acid be^ns to evaporate. (Berzelius.)
B. Tellubatb op Baryta.— «. JfowofeWwrafe.— Formed bv precipi-
tating the aqueous solution of chloride of barium with monotellurate of
soda. The precipitate, which is bulky at first, soon sinks down in the
form of a heavy white powder. If bitellurate is likewise present, this
effect does not take place, except on the addition of ammonia. The pre-
cipitate, after washing and drying, forms a white mealy powder. This
powder when heated above 200^ gives off its water before the acid begins
to decompose. It is slightly soluble in cold water, but more soluble in
boiling water, on the evaporation of which, it remains in the form of a
white earth. Dissolves easily and without decomposition in nitric acid;
not decomposed by ammonia. (Berzelius,)
AnhfirmiM. Hfdrmttd, Berzeliixs.
BaO 76*6 .... 46*ft4 BaO 76*6 .... 39*98 .m.... 39*82
TeO» 88-0 .... 53*46 TeO* .... 880 .... 45*93 45*85
3HO .... 27*0 .... 1409 14*33
BaO,TeO» 164*6 .... 100-00 + 3 Aq. ' 191-6 .... 10000 10000
5. BUeUurate.'^Acpieojia bitellurate of soda added to solution of chlo-
ride of barium throws down white Tolnminous flakes which do not agglo-
merate. They contain 10 per cent. (3 At.) of water. Water extracts
from them a salt containing a larger quantity of acid, and leaves the salt a
undissolved. (Berzelius.)
I
424 TELLUBIUM.
€. QtutdrUellurcUe. — Fonned by precipitating a tiai^rta^flalt wifcli
qoadrotellnrate of soda. Bulky, and more eaflily soluble in water tbaa
a or b. Turns yellow when heated, but recovers its whiteness on cooling.
When dissolved in acetic acid and eraporated, it remainB in the form of a
white earthy mass. (Berzelius.)
C. SuLPHOTBUiVRiTE OP Bariitm. — Formed by boiling s^nlphid^ of
barium with bisulphide of tellurium and water, and evaporating the filr
trate in vacuo. Larffe, transparent, pale-yellow, flat, obliquely truncated,
four-sided prisms, which are tolerably permanent in tke air^ and dissolve
▼ery slowly in water. (Berxeliys.)
Tellurium and Strontium.
A. TsLLURiTB OF Strontia. — As with baryta.
B. Telluratb of STRONTiA.«—J/'ono<eUurtite. — Formed by douUe
affinity. White flakes, which do not agglomerate; soluble in a large
quantity of water. (Berzelius.)
C. SuLPHOTBLLURiTE OF STRONTIUM. — Formed by boiling sulphide of
strontium with water and bisulphide of tellurium. The filtrate evapo-
rated in vacuo to the consistence of a syrup, shows signs of crystallisatioii
and dries up to a pale-yellow mass, tolerably permanent in the air, and
perfectly soluble in water.
Tellurium and Calcium.
A. Tellurite of Lime.— a. Monotelluritc-^l. On igniting 4 At. tel«
lurous acid with 1 At. lime, a white saline mass is obtained, which doef
not fuse at the melting point of silver. — 2. By double deoomposition :—
White flakes, slightly soluble in cold water, more soluble in hot water.
When the water is evaporated, the salt remains in the form of a white
earth. (Berzelius. V—^. BitelluriU.-^FuB^ when heated nearly to white*
jiess, and on cooling, solidifies in an opaque cake, which, when gently
pressed, is found to be made up of micaceous scales. (Berzelius.)— -c QvO'
droteUurite. — Fuses somewhat more readily than 6, giving off vapours of
tellurous acid, and likewise solidifies in micaceous s<»ies on cooling.
B. Tellurate of LiM£.'^J/'onof<;ZZtfrate.— By double decomposition.
White flakes which do not agglomerate. The solution in hot water leaves
the salt, on evaporation, in the form of a white powder. (Berzelius.)
G. SuLpnoTELLURiTB OF CALciuM.^Yellow, non-crystalline, soluble
mass, which decomposes rapidly when exposed to the air. (Berzelius.)
Tellurium and Hagnesium.
A. Tellurite of Magnesia. — Formed by mixing concentrated solu-
tions of monotellurite of soda and a magnesisrsalt. Much more soluble
than the baryta, strontia, or lime-salt. The solution, when exposed to tbe
air, deposits a mixture of carbonate and QuadrotfUurite <^ Magncna iq
white flakes.
/
(
TELLURIUM AND ALUMINUM. 42S
B. Tellubatb of Magnesia.— o. MonoieUurate. — Fonned by mixing
oonoeninbted solutions of monotellaiate of soda and a magnesia-salt. White
flakes, more soluble in water than the corresponding salts of the earthj
alkalis.~-6. BtteUur<Ue,'-^Bj donble decomposition with a concentrated
solution of bitellurate of soda. Still more soluble in water.
C. SuLPHOTRLLURiTB OF MAGNESIUM. — By precipitating the barium
compound with sulphate of magnesia, and OTaporating the filtrate in
▼aono. Pale-Fellow, crystalline, saline mass, soluble in water, and with
tolentble fiusility in aloohoL (Berxelius.) . .
Tellubium and Cesium.
SuLPHOTBLLURiTB OF Cerium.— -By precipitating an aqueous solution
of a cerotts salt with sulphotellurite of potassium. The precipitate, which
is brownish-yellow at first, soon acquires the dark colour of bisulphide of
tellurium; after drying, it erolves sulphur on distttlation. (BerseHus.)
Tellurium and Yttrium.
A« Tellurite of Yttria.«— By double decomposition. White^
▼oluminous flakes, insoluble in excess of the yttriansalt.
•
B. Tellurate of Yttria.— Yttria-salts give with mono- and bitel-
lurate of soda, white fl^es, insoluble in water and in excess of the yttria-
salt (Berselius.)
Tellurium and Glucinum.
A. Telluridb of Olucinum. — The two metals, when heated
together, unite without ignition, and form a white powder, which smells
of hydrotelluric acid on exposure to the air, and when thrown into water^
CTolyes that gas with violence. (Wbhler.)
B. and C. Tellurite and Tellurate of GLuciNA.-^imilar to the
^rreeponding yttria-salts. (Benelius.)
Tellurium and Aluminum.
A. Telluridb of Aluminum. — When a mixture of pounded tellurium
and aluminum is heated, combination takes place, attended with such
violent combustion, that the mass is projected from the tube like a shot;
for this reason, the tellurium must be added in small pieces. Black,
metallicHshining, sintered, brittle mass, which exhales an intolerable smell
of telluretted hydrogen when exposed to the air, and evolves that gas
with violence when immersed in water, the water quickly becoming red,
and afterwiurds brown and opaque, from separation of tellurium. ( W&hler,
Fogg. 11, 161 )
B. Tellurite of Alumina. — By double decomposition. White
flakes, insoluble in excess of the alumina-salt.
C. Tellurate of Alumina.— By double decomposition. White
flakes, soluble in excess of the alumina-salt. (Berselius.)
4S6 nLLURiuif*
Tbllubitb Airp Tbllubatb of Tboruia. — By doMe decomporitioii.
White precipitate, iotoluUe in excess of the ihorio»*nlt (Bersdiiu.)
Teixvbxvu axd Zibconium.
A. Tellubite of ZiBOONiA. — Bjd0obledeeompo6itio4. White flakeek
B. Tellubite of ZiBCONU.— Formed by precipitating monohydro-
chlorate of ziroonia with monotellarate of^^ soda. Voiuminous, semi-
transparent precipitate, soluble in excess of bydrochlorate of ziroonia.
(Berzelius.)
Tellvbium akp Chromium.
A. Tellurite of Chromic Oxide. — By double decomposition. Pale
greenish-grey^ bulky precipitate, soluble in excess of the chromic salt.
B. Tellubatb of Chbomic Oxidb.*— Greybh-green flakae, reddish
by transmitted lights soluble in excess of the chromio ealt. (Bendiiis.)
TBLLtTBIUM ANP UbAXOVM.
A. Tellubite of Ubanic Oxide. — Pale lemon-coloured insoluble
salt.
B. Tellubate of Ubanic Oxide. — Bulky, pale-yellow salt, insoluble
in excess of uianie nitrate. (Berzelius.)
Tellurium and Manganese.
Tellubite and Tellubate of Manganous Oxide.— •White flakes,
which) after uniting into a mass, exhibit a reddish tint. (Berzelius.)
With sulphotellurite oi potassium, manganous salts behave like cerous
salts. (Berzelius.)
Otheb Compounds of Tellurium.
With Bismuth, Zinc, Tin, Lead, Iron, Copper, Mercury, Silyer, and
Gold, both in artificial and in natural compounds.
i
I
437
Chapter XXVII.
BISMUTH.
Benelios. Gilb. 40, S86. Farther: A^w. 7, 70.
Lagerhielm. 8chw. IT,* 416.
Jacqaeuun. Ann. Chim, Fky$. 66^ 118; aLso J. pr. Chem, 14^ 1.
A. Stromeyer, Fog^. 26, 549.
Heints. Pogg. 63, 55 ; abstr. Jnn. Pharm. 52, 252.
Aq>pe. Po^^. 64, 297; abstr. Ann. Pharm. 56, 237.
Gladstone. Ckem. Soe. Mem. 3, 480; abstr. Liebig and Kopp*$ Jahre$^
bericM, 1, 432 (1847-8.)
SrvoiiYUBgf'^WwMUh, SUmtUhum, MarcatUa,
History. Recognized as a distinct metal bj Agricola in 1529; mori>
fully examined by Pott, Geoffroy, Berzelius, Liigerhjelm, J. Davy, and
Jacquelain. The existence of bismuthio acid was established by Bacholz
& Brandes {Schw. 22, 33), and by A. Stromeyer, Jacquelain, and Fremy,
Sources, Not rery abundant; mostly native; also as oxide; as cajv
bonate; slb sulphide, either alone or in combination with other metalli#
sulphides, as in Nickeliferons bismuth-glance, Needle-ore, and Bismuth-
lead-ore; also as Telluric bismuth.
Preparation on the large soo^.— Native bismuth is separated from the
matrix by fusion at a gentle heat.
Purification. Commercial bismuth, which may contain arsenic, iron,
nickel, copper, and other metals, is (tissolved in nitric acid; the clear
solution poured off and precipitated by water, and the precipitated mono*
nitrate of bismuth reduced at a moderate heat, either in a charcoal crucible
or with black flux. Arsenical bismuth, fused with twice its weight of
xinc, forms an alloy which yields arseniuretted hydrogen in Marsh'v
apparatus (p. 269). Eeinsch,
Properties. Crystalliies in ociohedrons and cubes, exhibiting vevy
distinct cleavage-planes paraUel to the lateral fe^ees of the octohedron.
Bismuth may be obtained in beautiful crystals by melting the ordinary
metal of commerce in a crucible, adding nitre from time to time, and
stirring, till — after the metal has been kept for some hours at a tempera-
ture as high as the melting point of nitre— a portion of the fused metal
taken out and exposed to the air, no longer assumes an indigo-blue and
afterwards a violet or rose colour which disappears on cooling, but a fine
428 " BISMUTH.
green or golden-yellow tint, and retains it after cooling. The bismntb is
then immediately poured into a heated pot, which is then covered with a
hot mnffie to prevent the surface from solidifying before the other part ;
the whole cooled pretty quickly (if the cooling be too slow, the metal
deposits itself in layers, not in nne crystals) ; the crust formed on the sur-
face pierced with a hot coal, as soon as the mass is half solidified, and the
portion which still remains liquid poured out. (Qnesneville, J. Pharm.
16, 554; also SiAw. 60, 378.)
Specific gravity of purified bismuth: 9*6542 (Karsten); 9*799 at 19"*
iMarchand £ Scheerer); of commercial bismuth: 9'822 (Brisson); 9*833
Herapath); 9*861 (Bernnan). Strong pressure rather diminishes than
increases the density. If commercial bismuth, of specific gravity 9*783,
be formed into a cylinder of snch a size as to go into a steel diamond
mortar, and subjected to very strong pressure, it is found that, under a
pressure of J 00,000 pounds, the metal retains its crystalline texture and
tenacity, and has a density of 9*779; a pressure of 150,000 pounds reduces
the density to 9*655; under 200,000 pounds' pressure — ^wnich causes the
steel to crack — the bismuth becomes very brittle, appears like grey steel
on the fractured surface, exhibits scarcely any crystalline structure under
the microscope, and has a density of only 9*556 (Marchand ic Scheerer,
J, pr. Chem, 27, 209.) Moderately hard, slightly sonorous ; brittle, but
may be somewhat extended by careful hammering. Reddish tin-white,
with moderate lustre. Fuses at 249"" (Grighton); at 264^ (Rudberg);
265^ (G. Herman, Pogg. 20, 283), and if cooled from that temperature,
solidines with an expansion of at least -^j (L, 256.) Boils at a dull white
beat, and if air be excluded, sublimes in laminas.
Atomic weight of Bismuth, — The atomic weight of bismuth is 71, or
1\ . 71 = 106*5, or 3 . 71 = 213, accordingly as bismuth-oxide is regarded
as BiO, or as BiH}*, or as BiO*. The similarity of bismuth to antimony
renders the last supposition the most probable of the three. According to
the author's experiments, the number 213 ought to be reduced to 210, or
«ven lower.
Compounds of Bismuth,
Bismuth and Oxyoen.
A. Suboxide of Bismuth f
The metal, when exposed to the air at ordinary temperatures, becomes
covered with a thin film of this substance; when heated in the air till it
fuses, it likewise becomes covered with this film, which is renewed as
often as it is removed, until the whole of the metal is converted into sub*
pxide: Bismuthrcuh, — Brownish or dark purple-brown. When treated
with hydrochloric acid, it is resolved into teroxide and metallic bismuth.
By heating magistery of bismtUh with protochloride of tin, a black powder
as produced, which, after washing and drying, glimmers, when heated,
with a yellowish-green light, and is converted into teroxide of bismuth ;
it turns yellow in the air at ordinary temperatures, and is soluble in heated
hydrochloric acid. (A. Vogel, Kastn, Arch, 23, 86.) When bismuth is
jiealed with microcosmic salt on charcoal in the inner blowpipe flame, a
clear glass is obtained, which turns black on coolinp^. (Berselius.) — Berse-
llus regards this substance as a peculiar oxide, but Proust and Sir H. Da'vy
regard it as a mixture of metal and oxide.
BISMUTH-OXIDE* 429
IT If a plate of pure bismuth be immersed in a solution of 1 part of
caustic potash in 5 or 6 parts of water, and made to form the positive pole
of a two-pair 6rove*8 battery, the neffative pole being formed of platinum,
the bismuth becomes successiyelj yeuow, red, violet, blue, green, and then
again colourless, after which the same series of colours is reproduced, but
less strongly. By interrupting the current at the proper time, any colour
of the series may be fixed. (Poggendorff, Fogg. 74, 586.) IT
B. BlSMVTfi-OXIDB.* BiO'.
Teroxide of Bismuih, Wumuthoxyd, Oxide bUmuthique.^^Foutki in An
impure state, as BismtUh-ockre,
Formation. — 1. The metal, when heated in the air till it boils, bums
with a faint bluish-white flame, and the vapours of the resulting bismuth-
oxide condense on colder bodies : Flower$ of BiamiiUh,'Flores BiMMUhL"-^
2. When bismuth is melted in the air for a long time, and the surface
frequently renewed, it is at first converted into suboxide of bismuth,
which, by longer heating in the air, is transformed into the teroxide.-^
3. Bismuth does not oxidize in moist air at ordinary temperatures; but if it
is partially covered with water, and the air, at the same time, is freed from
carbonic acid, the hydrated oxide is formed at first, and afterwards a small
quantity of yellow oxide in delicate crystals; but if the air is not freed
from carbonic acid, hydrated carbonate of the oxide is immediately formed
in white scales, and the surface of the metal becomes tarnished, first with
a red-brown, and then with a blue film. (Bonsdorff, Pogg. 41, 305.)—
4. Bismuth at a white heat decomposes vapour of water, and forms the-
teroxide. (Regnault.) It does not evolve hydrogen with boiling concen-
trated hydrochloric acid. — 5. Bismuth decomposes nitric acid at ordinary
temperatures, and oil of vitriol when heated, nitric oxide or sulphurous
being evolved and a bismnth-salt produced. Fuming nitric acid produces
deflagration with melted bismuth (Proust), and heats bismuth-powder to
redness. (Berzelius.)
Preparation. — 1. By gently heating bismuth in the air, and stirring
constantly. — 2. By gently igniting the mononitrate or the carbonate.—
3. By fusing the hydrated oxide in excess with caustic potash (Jacquelain),
or by boiling the hydrated oxide with caustic potash or soda, the anhy-
drous oxide is obtained in the crystalline state.
Prop^w.— Prepared by (1) or (2): Pale lemon-yellow powden
which, when heated, assumes for a while an oranffe-yellow, and afterwuxis
a red-brown tint ; by (3) : yellow, shining needles. Specific gravity of
* For oiidet which form lalifiable bases, it is important to have names as short as
possible, and so constructed as easily to enter into compound names. For this reason,
the term Bitmnth-Mnde is preferable to ojtide iff bismuth. Such names as ntiphate <^
bismuth-oxide are conTcnient enough, whereas terms like Sulphate of oxide of biemutk
are intolerably awkward and prolix. The still shorter terms Bismuth^wlphate, Bi»muth»
nitrate, Bcc, are also conrenient in many cases, and perfectly definite. When a metal
forms two classes of salts (#. g,, iron and copper) it is necessary to distinfpiish these salts
and the corresponding oxides by the terminations ous and ie, a method which has
already been adopted in several instances in the conne of this work {vid. Cerinm,
Uranium, Chromium, &c.); but for metals which form but one class of salts, {e.ff», bis^
muth, zinc, lead, siket) these terminations are superfloous. [W.]
430 BISMUTH*
tlie oxide obtained from the mononitrate: 8*1735 (Karsten), 8*968 (Po).
Bonllaj). Fuses at a strong red heat^ and solidifies on cooling* — ^provided
that an earthen eracible has not been used — ^in a crystalline mass. (Fuchs,
Sehw, 67, 429.) If the oxide is fused in an earthen crucible, silica
becomes mixed with it, and the dark brown liquid solidifies to a yellowish,
opaque glass, whose density at 4^ in racuo, according to Le Royer &
Dumas, is 8*449. The oxide yc^atilizes only at rery high temperatures.
J. Davy,
Thomson.
Lager-
Gm^s*
Klaproth, Mor-
Bacholz. Proust, veau.
Bi ....
213 ....
89-87 -.. 90 ....
89*863 ....
89*67
.... o9*^o .... oo «... oU
ao...
•24 ....
1013 .... 10 ....
10*137 ....
10*33
.... 10-72 .... 12 .... 20
BiO» 237 ....100*00 .... 100 .... 100000 .... lOOOO .... lOO'OO .... 100 .... 100
Deeompositions. — By gently heated potassium or sodium the oxide is
reduced to the metallic state, "with slight ignition (Gay-Lussac & The-
nard); by charcoal — easily before the blowpipe — to the metallic state;
by carbonic oxide to the metallic state. (Gm.) By sulphur it is conyerted
into sulphide.
C<mhinaiU>ns, — a. With Water. — Htdratb of BisHVTH-oxmE. —
Precipitated, on mixing the aqueous solution of the nitrate with an allcali,
in white flakes which dry up to a white powder. If the hydrocfalorate
is used instead of the nitrate, the precipitate contains chloride of bismuth
mixed with the hydrated oxide. (A. Stromeyer.)
b. With acids, forming the Salts of Bismuth-oxids^ or Bismuth*
Salts. — Bismuth-oxide dissolves easily in aqueous aeids. Some of the
salts are obtained by treating the metal with an oxidating acid. Bismuth-»
salts are very heavy; they are colourless, unless the acid itself is coloured ;
they exert a poisonous action. Those which contain a volatile acid part
with it on ignition. When fused on charcoal before the blowpipe, they
yield a button of bismuth and produce a yellow deposit on the charcoaL
Zinc, tin, cadmium, lead, iron, and copper precipitate the bismuth from
their solutions in the metallic state. Zinc, cadmium, tin, and iron reduce
the bismuth quickly and completely, the two former with rapid evolution
of gas and great rise of temperature, the two latter quietly. After the
free acid of the bismuth salt has been satorated, a bamc salt of bismuth is
precipitated, and this is likewise reduced, but very slowly. The reduced
bismuth presents the appearance of a blackish-grey dendritic powder,
destitute of metallic lustre. The reducing action of the lead ceases after
a time* Copper, antimony, and arsenic have no action on bismuth- salts.
(Fischer, Pogg, 8, 497.) Copper precipitates the bismuth very slowly
and imperfectly. (Jacquelain.) In a solution of mononitrate of bismuth
in 500 parts of dilute hydrochloric acid, the copper immediately becomes
covered with a grey metallic film, which gradually accumulates in the
form of small laminated crystals. On the application of heat, the whole
of the bismuth is deposited on the copper in the form of a crystalline film.
Reduction likewise takes place even with solutions still more dilute.
(Reinsch, J. pr, Chem. 24, 248.) Water decomposes most bismuth-
salts — ^provided they do not contain too large an excess of acid — into
dilute acid containing a small quantity of oxide in solution, and an
insoluble or difficultly soluble basic salt. Caustic ammonia^ potash, noda,
and baryta generally precipitate the white hydrate (from the hydro-
chlorate, however, they throw down a basic salt), and on boiling,
bismUthig acid. 431
especially if they are concentrated, they precipitate the yellow anhydrous
oxide. (A. Stromeyer, Pogg, 26, bbZ\ Jacquelain); the precipitate is inso«
luble in excess of alkali, even on bpiling. (Stromeyer.) Alkaline carbonates
throw down white carbonate of bismuth-oxide, somewhat soluble in
excess, but precipi table from the solution by a caustic alkali. (A.
Stromeyer.) According to L. Laugier (Ann. Chim, Phys, 36, 332), the
precipitate is perfectly soluble in excess of carbonate of ammonia, slightly
soluble in carbonate of potash, but perfectly insoluble in carbonate of
soda; according to Berzelius, however {Jdhrefher, 12, 166), bismuth-oxide
is not soluble in excess of carbonate of ammonia, unless phosphoric or
arsenic acid is present. Carbonate of lime added to a solution of the
nitrate completely precipitates the hydrated oxide, even in the cold
(Liebij^^ Mag. Fharm. 85, 114); so likewise do the carbonates of baryta,
strontia, and magnesia. (Demar9ay, TLnn. Fharm. 11, 240.) Phosphate
of soda precipitates white phosphate of bismnth-oxide. Hydrosulphurie
acid throws down all the bismuth in the form of brown-black sulphide,
even when a large excess of acid is present ; so likewise do the alkaline
hydrosnlphates, the precipitate not being soluble in excess. Iodide of
potassium throws down brown iodide of bismuth, easily soluble in excess
of the iodide. Alkaline chromates precipitate lemon-yellow chromate of
bismuth-oxide. Oxalic acid gives, after a while, a crystalline precipitate
of oxalate of bismuth-oxide« Infusion of galls gives a brownish-yellow
precipitate. Ferrocyanide of potassium produces a white precipitate
soluble in hydrochloric acid; lerricyanide of potassium, a pale yellow
precipitate soluble in hydrochloric acid. Sulphuric acid, and hyposulphite
of soda with addition of hydrochloric acid, do not precipitate bismuth.
c. With Silicic acid, with Glass-fluxes, and with several heavy
metallic oxides, forming vitreons masses.
IT C. PBROXIDfi OP BiSUVTH. BlCH.
When the yellow hydrate of bismuth-oxide is boiled with an alkaline
chlorite having a strong alkaline reaction, it turns brown, like peroxide
of lead, and is converted into the peroxide. (Arppe.) According to
Heints, this compound is likewise formed by trctftting the teroxide with
strong caustic potash and chlorine; but, according to Stromeyer and
Arppe, this process yields bismuthic acid, BiO^ {vid. p. 432).
Arpp€«
Bi
CnknUtiop.
... 213 .... 86*93
86-52 .... 86-70 .... 85-93
40
32 .... 13-07
1311 .... 1305 .... 13-32
Water
•• •••• «■•»
0-37 .... 0-25 .... 0-75
245 .... 100-00 10000 .... lOO'OO ... 100*00
By boiling with nitric acid, the peroxide is perfectly dissolved ; any
yellow or green residue that may be left behind procee<ls from an admix-
ture of bismuthic acid. (Arppe.)
Hydrated Peroxide. — When a bismnth-salt contains free chlorine,
caustic potash produces in it, not a white but a yellow precipitate, which
consists of the hydrate of a higher oxide, but can never be obtained free
from chlorine. When boiled with potash, it gives off water and is
converted into alight brown substance, containing bismuth 88*04. ...88*15,
oxygen 11*79.... 1162, water 0*27....0*23, which nearly corresponds to the
formala: 3BiO»+BiO»=Bi*0". t
432 BISMUTH.
BiBMUTHic Acid. BiCt
Wismulhsaure, Acide BUmtUhique, Peroxide of BwmUh,
When teroxide of bismatb is ignited with exceas of potasb- or
Bodfr-hydrate, and the air has access to the mixture — and likewise 'when
chlorine acts upon the teroxide diffused through caustic potash, — a
double salt is formed consisting of bismnthate of bismuth-oxide and the
alkali. IT According to Arppe, this latter process yields a hydrate o£
bismuthic acid, if the alkali is used in very large excess, and the anhy*
drous acid if the quantity of alkali is somewhat less. %
Preparation, — 1 . By treating brown bismuthate of bismuth-oxide and
potash rp. 445) with a cold mixt afire of 1 part of nitric acid and 9 parts
water, tnen with a more dilute acid, and afterwards washing with water
and drying. (A. Strome^er, Pogg, 26, 549 ; Brande^ Schw. 69, \5S.)—
2. By fusing bismuth-oxide with hydrate of soda, boiling the mass with
excess of soda-ley, and washing the brown powder which separates, first
with nitric acid, and then with water. (Fremy, CompU rend, 15, 1108;
also N, J. Pharm. 3, 30; see also Arppe, Ann. Pharm. 56, 239.)
Calculation. Arppe.
Bi 213 .... 8419 84-26
50 40 .... 15-81 1574
BiO« .'.... 253 .... 100-00 ZZ lOO'OO
Or: Calculation. StromeTer. Brandes.
BiO> 237 .... 93-68 9514 ... 95
20 16 .... 6-32 4-86 .... 5
BiO* 253 .... 10000 ZZ 10000 Z lOoT
Jacquelain regards bismuthic acid as BiO^ : A. Stromeyer, from his
analysis, assigns to bismuthic acid 1^ times as much oxygen as to bismuth-
oxide. The difficulty of obtaining bismuthic acid free from bismuth-
oxide renders it probable that the oxygen in the former has been
estimated too low rath^ than too high, and consequently that pure
bismuthic acid is really BiO^ corresponding to antimonic acid.
Decompoeitiong. — At the temperature of boiling mercury, bismathic
acid is resolved into oxygen gas and the yellow oxide, without giving off
water. When a mixture of this acid with charcoal, sugar, or other
organic substances is set on fire by a red-hot coal, it bums slowly away
like tinder, without deflagration. Hydrogen gas reduces the acid to the
state of oxide at a temperature below that at which the acid gives off
oxygen when heated alone; at a red heat, hydrogen reduces it to the metallic
state. Sulphurous acid, in the state of aqueous solution — but not in the
gaseous form, — slowly converts the acid into sulphate of bismuth-oxide.
Oil of vitriol instantly disengages oxygen gas from it, dilute sulphuric
acid more slowly. Phosphoric acid acts in the same manner. Cold
nitric acid does not dissolve bismuthic acid, unless it contains nitrous
acid ; heated nitric acid disengages oxygen and forms a solution of bismuth-
oxide. — 7 According to Arppe, bismuthic acid is distinguished from all
other oxygen-compounds of bismuth by being converted into the green
oxide, BiO',3BiO', when boiled with nitric acid, IT — Cold hydrochloric
acid gives off chlorine and forms a solution of bismuth-oxide. Aqueous
BISMUTH AND PHOSPHORUS. 433
kydriodio acid forms brown iodide of bismath and evolves iodine. Oxniic,
tartaric, citric, and acetic acid do not act upon bismuthic acid even at a
boiling heat; but if sulphuric acid be added, solution takes place with
violent effervescence. Aqueous alkalis have no action on it. (A. Stro-
meyer.)
Combinations. — IT a. With Water.— ZTyc^ro/e of Bismuthic Acid.-^
Obtained, when bismuth-oxide (prepared by boiling the hydrated oxide
with potash) is briskly boiled witn a very strong solution of potash, and
chlorine passed through the mixture. The oxide soon acquires a fine red
colour, and is converted into the hydrated acid. The compound thus
formed is mixed, however, with a considerable quantity of potash and
with the lower oxides of bismuth : from these it may be freed by washing
with water, then digesting in dilute nitric acid, and finally washing with
boiling water. It contains: bismuth 81*26, oxygen 15'48, water 3*26|
corresponding to the formula BiO^HO. (Arppe.) IT
6. With Salifiable Bases. — Bismuthates. — Bismuthic acid combines
with potash (Arppe), and forms a few double salts, the bases of which
are bismuth-oxide and an alkali.
Bismuth and Hydrogen.
Hydride of Bismuth f — When the negative electricity of a voltaic
battery is conducted into water by a bismuth pole, the bismuth imme-
diately blackens and becomes covered with black dendrites. (Ruliland,
Schw. 15,417.) — IF Meurer {Arch, Pharm. 2nd series, 36, 33) states that
a gaseous compound of bismuth and hydrogen is obtained by the action of
zinc on aqueous hydrochloric or sulphuric acid containing chloride of
bismuth. This statement has however been disproved by Schlossberger
<k Fresenius. {Ann. Pharm, 51, 418.) 1"
Bismuth and Carbon.
Carbonate of Bismuth-oxidb. — By double decomposition. White
powder, not soluble either in water or in aqueous carbonic acid : contains
less than 1 At. carbonic acid. — IT It contains exactly 1 At. carbonic acid.
(Heintz, Lefort.) — When a bismuth-solution is mixed with an alkaline
bicarbonate, a precipitate is formed, consisting of BiO',CO' + HO. (Lefort,
Compt. rend, 27, 268.) H
Bismuth and Boron.
Borate of Bismuth-oxide. — ^White, very heavy powder, insoluble in
water.
Bismuth and Phosphorus.
A. Phosphide of Bismuth. — The metal takes up but a small
quantity of phosphorus; the resulting compound exhibits before the
blowpipe a small greenish flame. (Pelletier.) Bismuth, by combining
with phosphorus, is rendered more brittle and less laminar. (Marx, Schw.
58,471.) Phosphuretted hydrogen gas throws down from nitrate of
bismuth-oxide a black phosphide of bismuth, which gives off all its phos-
phorus by distillation. (Berzelius; comp. Landgrebe, Schtv. 55, 100.)
VOL. IV. 2 p
434 BISMUTH.
B. Phosphitb op BisMnTH-oxiDB.-^Tercbk>ride of plioi^honu dia-
solyed in water and neutralised by ammonia^ gives with a aolntion of
bieinuth-oxide in hjdroehlorio acid — ^if the acid has been neutniliied
with ammonia as iiar as possible without precipitation — a copious white
precipitate, which^ when heated in a retort, ^ves off pure hydrogen ga&
(H. Rose.)
C. Ordiitart Phosphate OF Bismvth-oxibb; Bismuth-phosphate.
—Aqueous phosphoric acid forms with hydrated oxide of bismuth either
a white, insoluble powder which fuses to a white enamel, or a crystalline
salt soluble in water. (WenzeL)
D. Pyrophosphate of Bismuth-oxide. — ^This salt, which is preci-
pitated from bismuth-salts by pyrophosphate of soda, is soluble in excess
of the latter. (Stromeyer.) — IT Schwarsenberg, by adding pyrophosphate
of soda to a solution of bismuth-nitrate mixed with acetic acid, obtained
a white, amorphous, bulky precipitate, which, in the course of 24 honrs^
was conrerted into a heavy, crystalline powder. This, when examined
by the microscope, was found to consist of two different kinds of crystals.
When bismuth-oxide was boiled with acid pyrophosphate of soda, a
considerable quantity dissolyed. (Arm. Fharm. 65, 160.) IT
E. Metaphosphate of Bismuth-oxide. — Formed by mixing a solu**
tion of the nitrate, iSrst with metaphosphoric acid, and then with
ammonia. The precipitate is not soluble in excess of ammonia. (Pezsos.)
BfiBMUTH AND SULPHUB.
A. Bisulphide of Bismuth. — The sulphide of bismuth described
by Gregers Klack, appears to have this composition. (Berzelius, L5th-
rohr, 136.) — Bismuth may be fused in any proportion with the tersulphide.
(Lagerhjelm, Wertber.) When a fused mixture of equal parts of these
substances is left to cool, the bisulphide crystallizes out first, carrying
with it the nickel and copper contained in the commercial bismuth ; the
liquid metal may then be poured off. — If 10 parts of purified bismuth
be fused with 3 parts of sulphur in a crucible, the resulting mixture
again fused three times with fresh sulphur in an assay-crucible, and then
quickly cooled, a radiated mass is obtained, having a nest of crystals in
its interior. — Square prisms, with truncated lateral edges {Fig. 31, with-
out the €'faces); very thin and long crystals, with shining surfaces.
Specific gravity 7*29. Whitish-grey, with strong metallic lustre; fuses
more easily than the tersulphide. When heated out of contact of air, it does
not give off sulphur till the temperature is raised very high, and even
then the quantity sublimed does not exceed a mere trace. When heated
in the air, it gives off sulphurous acid. (Wertber, J, pr, Ckem. 27, 65;
abstr. Pogg. 57, 481.)
Werther. Wenzel. Heints.
Oryatals* Radiaied mam*
Bi 213 .... 86*95 86'20 .... 86*34 .... 85 .... 86*20
2S 32 .... 1307 13*81 .... 13*50 .... 15 .... 13*72
BiS« .... 245 .... 100*00 100-01 .... 99*84 .... 100 .... 99*92
BISMUTH AND SULPHUR. 435
That the sulphide of bismuth prepared by Werther, ia really BiS', is
sh6wu by its greater density and by the analysis. It is, however,
remarkable, that BiS' and BiS^ should have (as they appear to have)
the same crystalline form. At all events, it seems that the fusion of
bismuth witn sulphur may likewise yield the tersulphide, as indeed is
indicated hy the analyses of artificial sulphide of bismuth by Lagerhjelm
and John Davy, given below.
B. Tersulphide of Bismuth. — Found native as Biitntiih-glanee, —
Form^ by fusing together the elements which compose it. Precipitated in
brown-black flakes on mixing bismuth-salts with hydrosulphuric acid or
an alkaline hydrosulphate. — Both the native and the artificial varieties
belong to the right prismatic system. Right rhombic prisms, trttnoated
at the edges, Fig, 73, but having merely the ;>faces instead of acumt-
nation-faces; v! : 1^=91°; m : t, 134° 30'. Cleavage distinct parallel to t,
indistinct parallel to p and u, (W. Phillips, Phil, Mag. Ann, 2, 81 ; also
Pogg. 11, 476.) Specific gravity of the native variety, e*4....B'5 ;
specific gravity of the sulphide precipitated by sulphuretted hydrogen,
and then fused [with loss of sulphur?] out of contact of air, 7*001.
(Karst^n.) Colour, light lead-grey. Fuses less easily than bismuth.
The artificial yariety expands forcioly as it solidifies after fusion. (Marx.)
Lagerhjelm. J. Davy. H. Rose.
Artificial. Artificial. BiddarhyitaiL
Bi 213 .... 81-61 .... 81-62 .... 81-8 .... 80'98
3S 48 .... 18-39 .... 18-38 .... 18-2 .... 18-72
BiS» 261 .... 10000 Z 10000 Z 1000 Z. 99-70
At each successive fusion of the artificial sulphide, globules of metallic
bismuth separate from the solidifying mass. (Marx, Sehw. 58, 472 ; 59,
114.) The native tersulphide, heated in a tube, yields sublimed sulphur j
on charcoal, before the blowpipe, it fuses with ebullition, and leaves
metallic bismuth. (Berzelius.) By the addition of carbonate of soda,
the bismuth is easily reduced before the blowpipe. Nitric acid dissolves
the metal from the sulphide, with separation of sulphur. — When vapour
of water is parsed over red-hot sulphide of bismuth, sulphuretted hydro-
gen is evolved, and bismuth-oxide with a small quantity of metal, left
behind. (Regnault.) Hydrogen gas converts red-hot tmlphide of bismuth
into sulphuretted hydrogen and metallic bismuth; and phosphuretted
hydrogen at a gentle heat, produces sulphuretted hydros^en, phosphorus
and metallic bismuth. (H. Rose.) [On the behaviour of tersulphide of
bismuth with litharge, wd. Berthier, Ann. Chvnt. Pkys. 39, 249.]
C. Sulphite of Bismuth-oxide or BisinjTH-strLPHiTB. — Aqueous
sulphurous acid forms, with hydrated bismuth-oxide, a salt which is not
soluble either in water or in aqueous sulphurous acid ; when heated some-
what strongly, it gives oflf its acid. (Fourcroy.)
D. Sulphate op Bismuth-oxide or Bismuth-sulphate. — a. Mono-
sulphate. — 1. By decomposing the tersulphate c with water. (Gay-
Lussac.) — IT 2. By dissolving bismuth-oxide in sulphuric acid, evapo-
rating to dryness, and gently heating the residue till it turns yellow.
(Heintz.) IT — White powder insoluble in water. — White when cold,
yellow when heated. (Heintz.) Gives off sulphurous acid and oxygen
when heated. (Gay-Lussac.)
2f2
436 BISMUTH.
BerMlitti. Heintx.
f
BiO» 237 .... 95-56 85-5 .... 8488 .... 86-59
SO» 40 .... 14-44 14-5 .... 15-12 .... 13-34
BiO»,SO» 277 .... 100-00 100 .... lOO'OO .... 99*93
This salt is likewise obtained, in combination, boweyer, witb 2 atoms
of water, by washing the bisnlphate h with water. (Heintc.)
IT StntlphaU. — Separates in small delicate needles when a solution of
bismuth-nitrate in nitric acid is mixed with sulphuric acid. When
strongly heated, it gives off water and sulphuric acid, and is converted
into the preceding salt. Water likewise decomposes it: the crystals
must therefore be purified not by washing with water, but by pressure
between bibulous paper. (Heintz.) IT
Heintx.
BiO» 237 .... 68-85 6840 .... 68-36 .... 68-38
2S0' 80 .... 23-30 2379 .... 24-16 .... 24-12
3H0 27 .... 7-85 7-81 .... 7-48 .... 8-05
BiO»,2SO» + 3Aq 344 .... 10000 10000 .... 100-00 .... 100-55
c. Teraulphate, — ^Remains in the form of a white mass when bismuth
is heated with oil of vitriol, sulphurous acid and even sulphur being
evolved. According to Arfvedson, it is reduced to the metaHic state
when heated to redness in hydrogen sm. Water resolves it into a,
which remains undissolved, and c, which dissolves.
Lagerhjelm. ThomBon.
BiO» 237 .... 66-39 66-35 ... 6667
3SO» 100 .... 33-61 33-65 .... 33-33
BiO»,3SO» 357 .... lOO'OO 100-00 .... 10000
d. Acid Sulphate, — The aqueous solution when evaporated, yields
needle-shaped crystals, and afterwards a dry deliquescent mass of salt,
which, according to Gay-Lussac, evolves hydratea sulphuric acid when
heated.
E. Sulphide of Carbon and Bismuth. — Hydrosulpho-carbonate of
lime yields with bismuth-salts a dark brown pecipitate, which, when
added in excess, it dissolves, forming a red-brown solution. (Benselius.)
BisKtJTH AND Selenium.
Selenide of Bismuth. — The two substances, when heated together,
unite with faint evolution of light and heat, and form a silver-white
mass, having a crystalline fracture, and fusing at a red heat ; the fused
mass has a specular surface. (Berxelius.)
Bismuth and Iodine.
A. Iodide of Bismuth. — a. With a small proportion of lodine.'^A
mixture of equal parts of bismuth and iodine [about 1 At. metal to
1^ At. iodine| fuses when heated, and sublimes even below its melting
point, in lammsd having the metallic lustre. Water boiled with the
BISMUTH AND IODL\£. 437
compound turns yellow and sour, and leaves brown oxy-iodide of bis-
muth. (Berthemot, J, Fharm. 14, 616.) On heating a mixture of
218 parts (1 At.) of bismuth and 378 parts (3 At.) iodine, heat is
evolved, a large quantity of iodine volatilizes, and a grey, brittle mass
is formed, from which water takes up a small quantity of hydriodic acid,
but no bismuth. (Rammelsberg.)
Teriodide of Bismuth. — Formed by precipitating a bismuth-salt
with iodide of potassium. The bismuth-salt may be kept clear by means
of acetic acid, or it may be first mixed with hydrochloric acid, then
precipitated by water, and the iodide of potassium afterwards added;
lor that salt likewise decomposes the basic liydrochlorate of bismuth-
oxide. The yellow filtrate contains in solution a small quantity of iodide
of bismuth.
Brown cirstalline precipitate. Partially decomposed during washing,
but may be Jried without aifficulty. (Runmelsberg, Pogg» 48, 166.)
Rammelsberg.
Bi 213 .... 36-04 3602 .... 37*10
31 378 .... 63-96
BiP 591 .... 100-00
IT According to Arppe, the iodide obtained by dropping a solution of
nitrate of bismuth-oxide into a solution of iodide of potassium is con-
taminated with nitrate of bismuth-oxide ; but when a solution of iodide
of bismuth in hydriodic acid is diluted with water, a precipitate is
formed, consisting of pure BiP. IT
B. Oxy-iodide op Bismuth. — The chestnut-brown powder which
remains undissolved when iodide of bismuth, a, is boiled with water.
Zinc and iron decompose it on continued boiling with water. A concen-
trated solution of potash or soda, or strontia- water decomposes completely
with separation of bismuth-oxide; dilute solutions of potash and soda,
even when heated, and likewise aqueous carbonate of potash or soda,
baryta- water, and lime-water, decompose it but partially. (Berthemot.)
Red powder, completely insoluble in water. Consists of BiP+2BiO'.
(Arppe.)
IT C. Iodide op Bismuth and Hydrogen. — BiP+HI-|-8Aq.—
Separates, in octohedral crystals with rhombic base, when a solution of
iodide of bismuth in hydnodio acid is evaporated over sulphuric acid.
These crystals are decomposed by water, without separation of iodine, but
are completely dissolved by iodide of potassium. (Arppe.) IT
D. loDATE OP Bismuth-oxide or Bismuth Iodate. — -Iodic acid and
iodate of potash give with nitrate of bismuth, a white precipitate insoluble
in water. (Pleischl.) When a solution of nitrate of bismuth is precipitated
by water, and the liquid filtered from the precipitated mononitrate is
mixed with iodate of soda, a copious white precipitate is obtained, insoluble
in water, and very difficultly soluble in nitric acid. This precipitate,
when dried at 100^, contains no combined water, and when heated in a
retort, is resolved into oxygen gas, iodine vapour, and 39*65 per cent, of
fused residue. The latter contains about 5 At. teroxide of bismuth for
1 At. teriodide (Rammelsberg, Pogg. 44, 568.)
439 BISMUTH.
Bismuth and Bromine.
A. Bromide of Bismuth. — Bismutli does not combine with bromine
so readily or with eo much development of heat as antimony. The com^r
pound is formed by heating the pulverized metal with a large excess of
bromine in a long tnbe sealed at the end. The excess of bromine evapo-
rates, together with a small quantity of bismuth ; and the bromide of
bismuth remains at the bottom of the tube in the form of a steel-grey
substance which resembles fused iodine, melts at 200°, forming a hyacinth-
red liquid, and boils when heated nearly to low redness. It absorbs
moisture from the air, and is thereby converted into the sulphur-yellow
hydrated bromide of bismuth. By large quantities of water, it is resolved
into pure aqueous hydrobromic acid, and precipitated oxy-bromide of
bismuth. (Serullas, Ann. Chim. Fhys. 38, 323; abstr. Fogg. 14, 113.)
B. Bromatb of Bismuth-oxide or Bismuth Bromate. — Freshly
precipitated hydrate of bismuth -oxide, left in contact for a long time
with aqueous bromic acid, yields the undissolved salt a and the dissolved
salt 6. — a. Sesquibasic tSalt. — ^White, amorphous powder, which gives off
its water between 150° and 160°, and is decomposed with violence at high
temperatures, leaving yellow oxy-bromide of bismuth. (Rammelsberg.)
Hydnied, Rammelsbeig.
3BiO» 7110 .... 70-97 70-82
2BrO» 236-8 .... 23-64 23*39
6H0 54-0 .... 5-39 579
3BiO«,2BrO* + 6Aq lOOlS .... 10000 100 00
h. The acid solution evaporated over the water-bath ultimately gives
off bromine and oxygen gas, and leaves a small quantity of a salt which
deliquesces in the air. (HammeLsberg, Pogg, 55, 76.)
Bismuth and Chlorine.
A. Chloride of Bismuth. — Bvtter of BigmtUJi, — 1. Pulverized
bismuth thrown into chlorine gas at ordinary temperatures burns with a
pale blue light, and forms chloride of bismuth. ~2. The chloride is
likewise formed by heating 1 part of bismuth with 2 parts of corrosive
sublimate. — 3. By evaporating hvdrochlorate of bismuth-oxide to dryness
and distilling the residue out of contact of air. — Brownish or greyish-
white; opaque; with granular fracture; fuses very easily, forming an oily
liquid (J. Davy); volatilizes at a moderate heat. (H. Davy.) Vapour-
density = 11*35. (Jacquelain.) When distilled in vessels containing air
(not in vessels containing carbonic acid), it yields a small quantity of oxy-
chloride of bismuth in micaceous laminte. (Jacquelain.) Decomposed by
oil of vitriol, but only at high temperatures, and then with violent effer-
vescence, yielding hydrochloric acid gas and sulphate of bismuth-oxide.
(A. Vogel.) Water converts it into hydrochloric acid holding a small
quantity of bismuth-oxide in solution, and oxychlonde of bismuth.
BISMUTH AND CHLORINE. 439
y
Bl
3C1
.... 213-0
.... 106-2
66-73
33-27
•»««tit«
J. Dayy.
66-4
33-6
J.'
BiCl»
Bismuth rapour ?
Chlorine gas
.... 319-2
Vol.
1 .
6 .
.... 10000
Sp.gr.
29-5344
14-7258
Vol.
:4
1000
Sp. gr-
7-3836
3-6814
Vapour of Chloride of Bismuth 4 44-2602 » 1 110650
Hydrated Chloride of Biimuth or Ter-hydrochlorate of Bismuth-oxide.
— Separates in prisms^ when a solution of acid hydrochlorate of bismuth-
oxide is evaporated. Water resolves it into oxyohloride of bismatb, and
dilate hydrochlorio acid holding bismuth-oxide in solution.
B. OxYCHLORiDE OP BiSMUTH. — Basic Hydrochlorate of Bismuth-
oxid^, — 1. Formed by passing vapour of water over melted chloride of
bismuth, and afterwards expelling the unaltered chloride by the applica-
tion, of a stronger heat. — 2. By distilling chloride of bismuth in vessels
containing air. — 3. By decomposing chloride of bismuth with water, and
washing the precipitate. — 4. By precipitating a solution of bismuth-
nitrate with common salt, chloride of potassium, or hydrochloric acid not
too much diluted. An excess of the solution of chloride of potassium
redissolves the precipitate; but after the precipitate has been washed and
dried, the same liquid no longer dissolves it (Bucholz.)
White, crystalline, becoming yellow whenever it is heated (Jacaue-
lain); fuses at a red heat without decomposing. (Grouvelle, Jacquelain.)
Hot oil of vitriol converts it into sulphate of bismuth-oxide. By chlorine
at a red heat it is converted into oxygen gas and chloride of bismuth,
which volatilizes without residue. Potash, when hot and concentrated,
converts it into bismuth-oxide and chloride of potassium. (Jacquelain.)
The separated oxide, though free from chlorine, is not yellow but greyish-
black, and retains that colour when feebly ignited; when fused, however,
it turns yellow. ^Phillips, FhiL Mag. Ann, 8, 406; also Br, Arch,
39, 41.) Dilute solution of potash, even on boiling, extracts no chlorine
from it (A. Stromeyer, Jacquelain), or only a portion of that which it
contains. (Warington, Fhil. Mag. Ann. 9, 30.) Dissolves in hot nitrio
acid, and is left behind unchanged when the acid is evaporated. (Jacque-
lain.) Dissolves in hydrochloric acid, forming a solution of C. Totally
insoluble in water. (H. Rose.)
3Bi
3Cl
60
639-0 .... 80-56
106-2 .... 13-39
48-0 .... 6*05
Jaoqudain.
79-95
13-45
6-60
PhiUips.
.... 7819
.... 13-32
....
t...
....
Ar)>pe.
81-44
13-43
5-13
BiCl»,2BiO»
793-2 .... 100-00
Or:
BiCl»
2BiO»
100-00
819-2
4740
■ •>*
40-24
69-76
••.«
10000
793-2
100-00 *
IT When this compound is exposed to a high temperature, it is
resolved into neutral chloride of bismuth, which volatilises, and a residual
salt with excess of base, which appears to be composed of BiCl'-h^BiO^
(Arppe.) Acooiding to Heints, the oxyohloride obtained by treating
440 BISMUTH.
the hydrochloric acid solntion with water contains an atom of water:
BiCl',2BiO'+HO. IT
C. Aqueous Hydrochlobate of Bismuth-chloride, or Acid
Htdrochlorate of Bismuth-oxide. — Formed by dissolving the metal
in aqna-regia, or the chloride or oxide in hydrochloric acid. The colour-
less solntion, provided it does not contain too great an excess of acid,
deposits the compound B on the addition of water. With protochloride of
tin, it gives, according to A. Vogel, a siskin-green precipitate.
Bismuth and FiiUORinb.
Fluoride of Bismuth. — Deposited in the form of a white powder,
when the aqueous solution is evaporated. (Berzelius.)
Bismuth akd Nitrogen.
A. Nitrate of Bismuth-oxide or Bismuth-nitrate.— a, Mono-
nt^rato.-— Basic Nitrate of Bismuth, Bismuth-white, White coemetic, Pearl-white,
Mag:tstery of Bismuth^ Magisteriam Bismuthi, Blanc d'Espagne. — Formed by
decomposing 6 or c with water or with an insufficient quantity of
alkali; or by boiling c with excess of bismuth^-or by heating the
temitrate h to 148-7'* (300^ F.) for some hours. (Gladstone.^ The
usual mode of preparation is to saturate warm dilute nitric acid with
bismuth — which, to free it from arsenic, must be preyiously fused with -^
of its weight of nitre (J. Pkarm. 1 S, 688) — ^then dilute with a quantity
of water sufficient to prerent the corrosiye action of the acid upon paper,
but not to produce a permanent precipitate — pass the liquid through a
double filter — and precipitate by a quantity of water, weighing from
30 to 100 times as much as the bismuth contained in the solution. If
the quantity of water is too small, the precipitation is not complete; if it
is too large, a small portion of the precipitate redissolves. The precipi-
tate is thrown on a filter, washed several times with cold water, and
dried between bibulous paper. The filtrate, when warm, deposits slender
crystals, — ^bnt, according to Duflos, only when the nitric acid contains
hydrochloric acid; a mere trace of the latter is however sufficient to
produce the effect. Common salt, according to Phillips, precipitates
oxychloride of bismuth from the filtrate. Duflos, (Schw. 68, 191; i^. Br.
Arch. 23, 307) dissolves 1 part of the crystals of salt 6 in 2 or 3 parts of
warm water; filters to separate any insoluble residue of bismuth-arseniate;
pours the filtrate into 24 times its bulk of hot water, stirring all the
while; leaves the precipitate to subside, and decants the liquid; then
agitates the deposit with a fresh quantity of water; again leaves it to
subside and decants ; and finally dnes the precipitate on a brick between
many folds of bibulous paper. The preparation thus obtained is free
from arsenic. Ordinary magistery of bismuth frequently contains arsenic.
In that case it yields arseniuretted hydrogen, when treated with zinc and
hydrochloric acid in Marsh's apparatus. (Cbevallier^ J. Pharm. 15, 383;
Reinsch, Bepert. 64, 206.)
Very soft, silky needles and scales, or — when prepared from the
crystals — loosely coherent powder having a faint pearly lustre. Reddens
moistened litmus-paper. If washed too long with water, especially with
hot water, it is converted into a more basic salt. (He]4>erger; Buchner,
JieperL 55, 289, and 306.) When ignited, it leaves teroxide of ^bismuth,
KITRATB OF BISMUTH-OXIDE. 441
With proiocUoride of tin, it assumes an orango-yellow colour, which,
after some days, or immediately on boiling, changes first to brown
and afterwards to black. (A. Vogel; vid. Svhoande of BismiUh, p. 429.)
Slightly, if at all, soluble in water, which, according to Duflos, extracts
from it a more acid and leaves a more basic salt. It does not blacken in
sunlight, unless it contains chloride of silver (Klaproth, Busch. Br. Arch.
24, 341), or unless portions of filter-paper are attached to it. (Wittstein,
Bepert. 74, 243.)
Menigaud.
Her* Grou- Phil- Dried
berger. Dnfloe. TeUe. lips. at IOC.
BiO» 237 .... 79 .... 79-70 .... 80-00 .... 81-37 .... 81-92 .... 85-33
NO» 54 .... 18 .... 14-44 .... 1358 .... 13-97 .... 1836 .... 14-67
HO 9 .... 3 .... 5-86 .... 6-42 .... 466
BiO»,NO» + Aq. 300 ....100 .... 100-00 .... 10000 .... 10000 .... 10028 .... 10000
Magistery of bismuth, obtained by precipitating with water the
solution of the crystallized salt b in nitric acid, ann dried for several
weeks, by heating it over the water-bath during the day and placing it
under a receiver with oil of vitriol at| night — whereby its weight was
slowly but continuously diminished — ^was found by the author to contain
80-67 per cent, bismuth-oxide, 2-92 water, and therefore 16 '4 1 nitric
acid. The water was determined by passing the aqueous vapour, evolved
by heating the substance in a glass tube, first over ignited metallic
copper, and then into a tube containing chloride of calcium ; the water
thus collected was inodorous. Even though the quantity of bismuth-
oxide found in this analysis should be rather too great — inasmuch as the
salt may have been pajrtially decomposed by the prolonged heating to
which it was subjected in drying — the experiment proves at least that the
salt, when dried at 100% contains water as an essential constituent, con-
traiy'to the results obtained by Phillips and Menigaud. IT Gladstone
finds that the salt obtained by heating the crystallized nitrate h to 300%
likewise contains one atom of water. His analysis gives, — bismuth-
oxide, 79*23 per cent. ; nitric acid, 18-49; water (mean of four experi-
ments), 8-22. The water was determined in the manner just described;
the nitrogen by the absolute method used in orranic analysis, and the
nitric acid calculated therefrom; and the bismuth- oxide, by igniting the
salt in a platinum crucible.
The composition and properties of the basic nitrates of bismuth-
oxide have lately been examined by Becker, (Arch. Pharm. 55, 31, and
129; abstr. Ann. Fharm. 68, 282), whose results difi'er considerably
from those above detailed. He finds that the basic nitrate, directly
obtained by treating the temitrate with cold water, contains 2 atoms of
water, ana that it has invariably the same composition, whether the ter-
nitrate from which it is formed is in the state of crystals or of a very
acid solution; and, further, that the same basic salt is obtained by
digesting metallic bismuth in the concentrated acid solution of the temi-
trate. The composition of this basic nitrate is as follows :—
Becker.
BiO»
237 .... 76-65 ...
54 .... 17-53 ...
18 .... 5-82 ...
a.
77-33
17-20
5-47
••••
b.
77-51
17-23
5-26
• ••t
• *••
• •• •
77-47
NO*
2HO
17-09
5-44
BiO*,lK>*+2Aq.
309 .... 100-00 ..
10000
• •■■
10000
• ■ • ■
ICOCO
442 BISMUTH.
a and b were precipitated by water; c wai obtained by difettiag
polverized binnatb m the nitric acid eolution. The bismuth-oxide ana
nitric acid were determined directlj, the water by loss. — The ealt^ when
heated to 100°, loses half its water, as previously shown by Heintz.
When freshly precipitated, this salt is somewhat freely soluble ia
water, especially if the water contains nitric acid. Hence if, after the
precipitation of the basic salt, the supernatant liquid be mixed with a
large quantity of water, the precipitate is completely redissolved ; bat,
after a time, the length of which depends upon the temperature and
the quantity of acid present, a basic salt separates out. If the solution
contained free nitric acid, and the water added was cold, the salt thus
separated consists of 5BiO',4NO'-|-9Aq. This, according to Becker, is
the true magutery of bismtUh, inasmuch as, according to the usual direc-
tions for preparing that substance, (see page 440) the same change takes
place in washing the precipitate on the filter. A portion of the preci-
pitate is, however, dissolved during the washing, and separates when
the filtered Jiquid is left at rest for a while. The disappearance of the
precipitate during washing is however occasioned, not so much by
actual solution, as by the mechanical condition of the precipitated mono*
nitrate, which, in fact, consists of very soft and light laminsB, easily
washed away by the water, whereas the true magigtery forms thick, short
prisms. To avoid loss, it is, therefore, advisable to wash the precipitate
by decantation, after nourinj^ off the acid liquid. The analysis of
magistety of bismuth, ootainea as above, gaye the following results :
Becker.
6B10" 1185
4NO« 216
9H0 81
79-91 ...
.... 79-85
• ■•t
8018
14-62 ....
.... 14-52
■ •••
14-58
5-47 ....
5-63
• *••
5-26
5BiO»,4NO» + 9Aq. 1482 .... 10000 10000 .... 10002
This analysis agrees very nearly with that of Herberger, given on
page 441 ; the latter is, therefore, more accordant with the formula just
given than with that of the mononitrate, or with that which Herberger
himself assigned, vis., 4BiO\3NO»+9Aq.
Magistery of bismuth is not sensibly soluble in cold water, but the
water extracts acid and a small quantity of oxide from it; hot water
converts it into a heavy dingy-coloured powder. The powder which
remains after long boiling, still retains 1 per cent, of nitric acid, which
cannot be completely extracted by water.
A salt containing the same proportions of base and acid, but with
] 2 atoms of water, is obtained by evaporating a concentrated solution of
the ternitrate at a strong heat: the salt then separates in crystalline
crusts, which, when pressed between bibulous paper, are reduced to a
very hard, shining, crystalline powder. It contains 78*49 BiO*, 13 '99
NO*, and 7*55 water, corresponding to the formula 5BiO', 4NO*-fl2Aq.
If the precipitate first obtained by the action of cold water on a solu-
tion of the ternitrate, be heated in contact with a free acid — or if the
same acid solution be poured into hot water — a white, very loose powder
is precipitated, containing 80 24 BiO», 15-43 NO*, and 4-33 water,
which corresponds to the formula 6BiO', 5NO' + 9Aq. — This salt is
decomposed by water more readily than the magistery of bismuth. If it
be washed with water as long as the filtrate continues to exhibit a
strongly acid reaction, the residue then left consists of prisms of unequal
NITRATE OF BISMXJTH-OXIDE. 443
magnitude, and forms a heavy and not perfectly white powder. It consists
of 4BiO', 3NO* + 9Aq., and is, therefore, identical with the magisterjr pf
bismuth obtained by the method of Duflos.
Lastly, if the mononitrate, completely freed from the adheriog acid
liquid, be treated with water likewise free from acid, it dissolves com?
pletely; but the liquid, after a while, becomes milky, and, after long
standing deposits a white, amorpbous powder, containing 5BiO^ dNO^ +
SAq. This salt may be formea, in addition to the true magistery of
bismuth, if too large a quantity of water be used and the greater part
of the acid liquid renfoved. IT
b, Temitrate. — Formed by dissolving the metal in hot nitric acid,
evaporating the solution, and leaving it in a cold place. — Transparent and
colourless, oblique six-sided and eight sided prisms, terminated with
several faces j tne crystals appear to belong to the doublv oblique pris-
matic system. At 100°, they separate into a solid and a liquid portion;
the latter solidifies suddenly on cooling. (Graham.) When distilled,
they give ofi* hydrated nitric acid, and leave first the mononitrate a and
afterwards the pure oxide, (fierzelius.) When exposed to the air at 87^|
they give off so much water and acid, that they are reduced to a basic
salt, and, if afterwards heated to 260°, sustain scarcely any further loss.
The total loss amounts to 32*47 per cent., and there remains 67*53 pet
cent, of salt a (Graham, Ann, Pharm. 29, 16.) [These numbers are
not exact, as Liebig correctly remarks.] H According to Gladstone, the
crystals, when heated to 150®, are reduced to BiO', NO'H- Aq. (i^trf. p. 440)
and this when heated to 260°, gives up its acid and water. 1 — The
crystals, when thrown on red-hot coals, detonate slightly and emit red
sparks j these effects are produced in greater intensity on rubbing the
crystals with phosphorus. (Bru^natelli.) — Dilute nitnc acid dissolves
them completely ; pure water only partially, the solution consisting of
salt c, while a remains undissolved. A small quantity of water produces
loss of the salt a, and the resulting solution treated with more water
gives a fresh precipitate. With a sufficient quantity of water (according
to Grouvelle, Ann, Chim. Pkys, 19, 141), 100 parts of the crystals yield
about 54 parts of salt a. With 50 parts water, 100 parts of the crystals
yield 16 parts of salt a; with 100 water, 18; with 200 water, 27; with
400 water, 32; with 800 water, 39; with 1,200 water, 43; and with
1,600....! 2,800 water, 45 parts of salt a. (Duflos.) The liquid obtained
with 1,600 ...12,800 water, becomes turbid if warmed after filtering, and
deposits crystalline scales of salt a.
Cryttallized. Duflos. Berzelias. Graham.
BiO» 237 .... 49-38 48-3 .... 488 .... 4949
NO» 162 .... 33-75 33-5 .... 33-7
9HO 81 .... 16-87 18-2 .... 17*5
BiO»,NO» + 9Aq. 480 .... 10000 1000 .... 1000
Crytttdlized, Gladstone.
BiO» 237 .... 48-46 48-15
3N0« 162 .... 33-13 3238
lOHO 90 .... 18-41 19-47
BiO»,3NO«+10Aq. 489 .... 10000 ~.. 10000
€. Aqueotu Acid Nitrate of BUmuth-oxide, — Obtained by dissolving
bismuth or bismuth-oxide, or salt a, or salt b, in nitric aoid. The stronger
the acid, the greater is the quantity of bifmuth that the solution can
444 BISMUTH.
contain; water precipitates from it the salt a, provided the acid is not in
very great excess. The solution, after precipitation with a large quan-
tity of water, still retains 7 parts of bismuth-oxide to 19-15 nitric acid
= 1 At. BiO» : 12N0»; if this liquid be so gently eraporated that no
nitric acid is given off from it, there remains a non-crystallizable syrup,
which mixes with water without turbidity. (Duflos.) Acetic acid added
to a solution of bismuth in nitric acid prevents the precipitation by water.
Freshly precipitated bismuth-oxide is not perceptibly soluble in caustic
limmonia or carbonate of ammonia (p. 431).
B. Ammonio-iodidb op Bismuth. — 100 parts (1 At.) of iodide of
bismuth, heated in a stream of ammoniacal gas, take up 9*505 parts
(rather more than 3 At.) of ammonia, and are converted into a brick-red
mass, which, when treated with water, gives up bydriodate of ammonia,
without change of colour. (Rammelsberg.)
C. Ammonio-chloridb of Bismuth. — Chloride of bismuth, when
gently heated, absorbs ammoniacal gas.
D. Chloridb of Bismuth and Ammonium.— A solution of 319*2
parts (1 At.) of chloride of bismuth, and 106*2 parts (2 At.) of sal-
ammoniac, yields on evaporation, double six-sided pyramids, isomer-
phous with those of chloride of antimony and ammonium (p. 374).
(Jacquehun.)
2NH*
Bi ....
5Cl....
Cryttallized.
JacqueUin.
Or:
36 .... 8-45 ..
2NH*C1
. 106*8 ....
2507
213 .... 5000 ..
49-78
BiCl*
. 319-2 ....
74-93
177 .... 41-55 ..
41-89
2NH<Cl + BiCl» 426 .... 10000 4260 .... 100-00
IT A solution of 6 At. sal-ammoniac and I At. chloride of bismuth
yields tabular rhombic crystals containing 3NH^ClH-BiCP. (Arppe.) IT
The hydrate, carbonate, phosphate, and mononitrate of bismuth-oxide,
when freshly precipitated, dissolve readily in sal-ammoniac but not in
nitrate of ammonia. (Brett, FhiL Mag. «/« 10, 98 and 335.)
Bismuth and Potassium.
A. BiSMUTHiDE OF PoTASSiUM. — a. Four volumes of bismuth-powder
combine readily with one volume of potassium, at the melting-point of the
latter, and form a brittle, easily fusible mixture, of fine lammar texture :
it oxidates when exposed to the aiiv— dissolves with effervescence in
water — and still more readily in dilute acids. (Gay-Luesao k Th^nard.)
The combination is attended with development of light and heat. The
resulting compound is tin-white and fine-grained; does not expand in
solidifying^ from a state effusion; perforates an iron spoon in which it is
melted. (Marx, Schw, 58, 463.)-— 6. An alloy of bismuth and potassium
may likewise be formed by heating very strongly for two bours in a
covered crucible, a mixture of equal parts of bismuth and cream of tartar
covered with lamp-black (Yauquelin, Schw. 21, 221); or of 120 parts
bismuth, 60 parts of cream-of-tartar carbonized and somewhat related,
and 1 part (HF nitre. (Serullas, Ann, Ohim. Phys, 21, 200.) The alloy
obtained by the process of Sernllas emits sparks when cut with the
BISMUTH AND POTASSIUM. 445
sbeus ; foflea and burns yividl j when broken np ; and when thrown on
mercnrj covered with water^ moves abont with great rapidity. (Serullas.)
T B. BisMUTHATB OP PoTASH. — KO,2BiO*+Aq. — Hydrated bia-
innthic acid is somewhat soluble in boiling caustic potash. Acids added
to the colourless solution throw down a white or reddish precipitate, the
insoluble red portion of which is the salt having the composition above
stated. (Arppe.)
C. Sulphate op Bismuth-oxidb and Potash. — BiO',3SO*H-
SKO^SO'. — Obtained by adding sulphate of potash in large excess to
a very concentrated solution of bismuth-nitrate in nitric acid. If a
dilute solution of bismuth be used^ the precipitate appears to be a mixture
of various salts. (Heintz.) T
D. BisifUTHATE OF BisMUTH-oxiDE AND PoTASH. — a. Ochre-yellow
Salt. — Formed by heating 5 parts of hydrate of potash in a silver crucible
till it is reduced to a state of tranquil fusion, then adding 1 part of
bismuth-oxide, and heating for a quarter of an hour^ at a continually
increasing temperature. The oxide turns greenish, and dissolves, in
proportion as it becomes more highly oxidized by the oxygen which
the potash absorbs from the air, forming a transparent, ochre-yellow
liquid. This liquid, when slowly cooled, solidifies to a mass resembling
Aventurine, and containing a great number of fine crystalline scales.
Continued washing with water withdraws from the mixture the greater
portion of the potash, and leaves the double salt (ochre-yellow, according
to Bucholz & Brandes), mixed, however, with silver from the crucible, n
too large a quantity of bismuth-oxide is used, a portion of it remains at
the bottom of the crucible, crystallized in needles. (Jacquelain.)
Or : Jacquelain.
KO 47-2 .... 2-39 KO... 47-2 .... 239 .... 226
eBiC 1422-0 .... 71-99 8Bi.... 17040 .... 86'27 .... 8616
2BiO« 5060 .... 25-62 280 2240 .... 1134 .... 1156
K0.6BiO»,2BiO* 19752 .... 100*00 1975*2 .... 10000 .... 9998
In Jacquelain*s analysis, the silver mixed with the salt is deducted :
he states that the salt likewise contains a small quantity of water.
This compound is permanent in the air. It gives ofi* water at 125^ and
oxygen at 145°; and, at a red heat, is converted into a deliquescent mixture
of bismuth-oxide and potash. In the preparation of this salt, it is
probable that a compound richer in potash is first formed, and that this
compound does not give off oxygen even when strongly ignited : it is
however converted by washing into the compound containinc^ a smaller
quantity of potash. The salt when treated with very dilute nitric,
sulphuric, or acetic acid, gives off oxygen gas. It dissolves instantly in
melted hydrate of potash, whereas bismuth-oxide dissolves but slowly, in
proportion as the oxygen of the air is absorbed by the potash and
transferred to it. (Jacquelain.)
6. Brown ScUi, — BismuthcUe puce de Potasse, — To prepare this salt,
bismuth-oxide obtained by igniting the nitrate is boiled for a long time
with chloride of potash or soda^ obtained by precipitating chloride of lime
with carbonate of potash or soda, the boiling being continued till the
oxide assumes first a brown-yellow and then a black-brown colour: the
r^
446 BISMUTFI.
Efodact is tiien washed witfi water. Hydraied Msmntli-oxide oiridfzes
^88 quickly than the anh jdrons oxide ; nitrate of bisntnth-oxide^ dven
when the chloride of potash is mixed with excess of canstic potash, yields
the compound contaminated with oxjchloride of bismuth. — 2. Six parts
of bismuth-oxide, either h jdrated or anhydrous, are diffused in a solution of
40 parts of potash-hydrate in 500 parts of water, and chlorine gas rapidly
passed through it, in such quantity however that the potash may remain
in excess, the liquid being agitated ail the while, and kept &t a tempera-
ture between 90° and 100^. The oxide turns brown in a few minutes,
whereupon the liquid is boiled for a short time, the solid product washed
by decantation, and then dried at 100^. Flea^brown powder.
Caleidation.
KO 47-2 4-52
2BiO» 4740 4535
2BiO* 506-0 48-41
2HO 18-0 1-72
KO,BiO* + 2BiO»,BiO* + 2Aq 1045'2 10000
Calculation. Sttcqaelwm.
KO -47-2 .... 4*52 4*63
4BiO» 9480 .... 9070 8986
40 320 .... 306 3-28
2H0 18-0 .... 1-72 2-22
1045*2 .... 10000 ZZ 99-99
According to Jacquelain : 2KO,8BiO^H-^Aq. % Heintz, by suspending
bismuth-oxide in a solution of potash so strong that it solidified on
cooling, and passing chlorine through it, leaving the potash in excess
however, obtained an ochre-yellow substance, which he regards as a com-
pound of peroxide of bismuth with potash and water: KO, 2BiO* + 3H0. T
c. Purple Salt. — Bismutkaie pourpre de PotcLSse. — Formed by diffusing
6 parts of bismuth-oxide or its hydrate in a saturated solution of 40 parts
of potash-hydrate in cold water, and passing chlorine through, as in b.
The oxide first becomes ochre-yellow, and then brown-red. As soon as
this latter change has taken place, the stream of chlorine is interrupted ;
the liquid boiled for a few minutes; then decanted boiling hot; and the
deposit washed by decantation, first with alcohol and then with water.
If water were used in the first instance, it would precipitate the bismuth-
oxide held in solution by the carbonate of potash. Purple powder.
(Jacquelain.)
KO 47-2 5-91
Bi03 237-0 29-65
2BiO» 506-0 63-31
HO 9-0 M3
KO,BiO* + Bi03,BiO* + Aq 7992 10000
Or : Jacquelain.
KO 47-2 .... 5-91 5-22
3Bi 639-0 .... 79-96 81-22
130 104-0 .... 13-00 12-18
HO 9-0 .... M3 1-36
799-2 .... 10000 99-98
According to Jacquelain: 2KO,7BiO*+3Aq. — ^which formula certainly
accords better with the analysis.
BISMUTH AND SODIUM. 447
IF B. lODIDltf OF BlSMtTTH AND PoTASSTTJM. — $Kl,BiP+4H0. —
Obtained by mixing ter-iodide of bismath with iodide of potasfsium in
sedation, and eraporating. Tbin rhombic tables. When a solution of
iodide of bismuth in hydriodic acid is mixed with iodide of potassiam and
evaporated, small, black, easily soluble crystals are obtained, which, when
heated, ^ive off iodine and are converted into a red substance containing
4KI-fBiP: the black crystals are probably 4KI + BiP + HI. (Arppe.) t
F. Chloride of Bismuth and Potassium. — Formed by slowly
evaporating an nqneous solution of I49'2 parts (2 At.) of chloride of
potassiam and 31 9 '2 parts (I At.) of chloride of bismuth, till a crystalline
film forms on the surface, and leaving the solution to cool. Khombic
octohedrons. (Jacqnelain,)
Crystallized, Jacqnelain.
2K 78-4 .... 15-27 15-22
Bi 213-0 .... 41-49 41-70
5Cl 177-0 .... 34-48 34-84
5H0 45-0 .... 8-76 8*24
^ irr — — ^
2Ka,BiCl»+5Aq. 513-4 .... 10000 106-00
Or:
2KC1 149-2 29-06
BiCP 319-2 62-18
5HO 45-0 8-76
513-4 100-00
IT According to Arppe, tfie compound 2KCl,fiiCl^ is likewise formed
when 3 At. chloride of potassium and 2 At. bismuth-oxide are dissolved in
hydrochloric acid and the solution evaporated. By proceeding in a
similar manner with 2 At. chloride of potassium and 1 At. bismuth-oxide,
the compound SKCl^BiGl' is produced. IT
Bismuth and Sodiuht.
A. Bismuthide of Sodium. — 4 volumes of bismuth -powder and
1 volume of sodium, heated above the melting point of the latter, unite and
form a yellowish -grey, very brittle, fine-grained mass, which is less fusiVle
than bismuth, oxidizes quickly in the air, and effervesces strongly with
water and aqueous acids. (Gay*Lussac & Th^nard.) The combination of
4 volumes of bismuth-powder and 1 volume of sodium takes place several
degrees below the melting point of bismuth, and is attended with vivid
combustion. The alloy ha# a steel-grey colour, inclining to tin-white,
and a broadly laminar structure; fuses more readily than bismuth^ and
expands in solidifying from fusion, but less strongly than bismuth. When
immersed in water or in aqueous acids, it liberates hydrogen for a short
time only, and becomes covered with a black powder; if it be then fused
a second time, it will again produce effervescence for a while, on immer-
sion in water. (Marx, Schw, 58, 462.) This alloy may likewise be
obtained by igniting bismuth with charred soap. (SeruUas.)
B. BiSMUTHATE OF BisMUTH-oxiDB AND SoDA. — Bismuth-oxide when
fused with hydrate of soda or treated with soda-ley and chlorine, exhibits
phenomena similar to those which are produced by fusing it with hydrate
of potash or treating it with potash-ley and chlorine. (A. Stromeyer,
Fremy.)
448 BISMUTIf«
C. Chloride of Bismuth and SoDnric. — Obtained by eyaponiiiDg
and cooling an aooeons solation of 117*2 parts of chloride of sodiam and
319*2 parts of chloride of bismuth. Ill-defined, dellqaescent prisms.
(Jacquelain.)
OyttaOized.
Jaoqndi
2Nt ..
46*4
9-46
••■•...a
9-8
Bi
t ■••••••••■■ at ■••«•• •••«•»■
2130 ....
43-44
43*5
5Cl ...
177-0 ....
3609
35*8
6HO ...
54-0 ....
1101
10*9
2Naa,Bia> + 6Aq
49V 4 ••••
100-00
• .*•.#*•
1000
Or:
2N»C1
117-2
23*90
BiCP
319-2
65 09
6HO
540
11-01
'
490-4
•••••*.•
100-00
IT Arppe, hy evaporating a solation of 3 At chloride of sodium
and 2 At. bismuth -oxide in hydrochloric acid, obtained a salt which
ctystallized in six-sided prisms with three-sided summits, and contained
2NaCl,BiCl«+2Aq. IT
Bismuth and Silicium,
SiLiciDE OF Bismuth {Bismuth-blende or BUmtithUe of Breithaupt)—
which has a density of 6*909, a conchoidal or earthy fracture, a green or
yellow colour and feeble lustre, and is opaque, appears from Kersten's
analysis {Pogg. 27, 81), to be BiO', 2SiO*, — but likewise contains man-
ganic oxide, ferric oxide, phosphoric acid, and hydrofluoric acid. {Com--
pare Hiinefield, Schw. 53, 85; Breithaupt, Sckw. 50, 307; 54, 237;
Breithaupt & Plattuer, Pogg. 53, 627.)
Bismuth-oxide dissolves in glass, and gives it a yellowish colour.
Bismuth and Tunostkn,
Sulphotunostatb of Bismuth. — BiS',dWS'. — Dark brown preci-
pitate, which turns black on drying.
Bismuth and Molybdenum.
A: Moltbdate of Bismuth-oxide. — Formed by mixing molybdate
of potash with nitrate of bismuth -oxide. Lemon-yellow precipitate,
soluble in 500 parts of water and in the stronger acids. (Richter.)
B. Sulphomolybdate op Bismuth. — BiS',3MoS'. — ^Dark brown pre-
cipitate. (Berzelius.)
C. Persulphomolybdate of Bismuth. — The aqueous solution of
persulpbomolybdate of potassium gives a red-brown precipitate with
bismuth-salts. (Berzelius.)
BISMUTH AND ANITMONT. 449
Bismuth and Chromium,
Chromatb of BiSMUTH-oxn>B.-«Fonned by mixing chromate of
potash with nitrate of bismuth-oxide. — Lemon-yellow powder, which^
according to Moser, is very slightly soluble in water, and, according to
Orouvelle, is reddened by potash. — If bichromate of potash be used for
the precipitation, the precipitate is likewise pulverulent and lemon-
yellow at first, but becomes crystalline and orange-yellow by washing
and drying. (Nolle, Ann. Fharm. 2, 94.)
Bismuth and Arsenic.
A. Arsenide op Bismuth. — ^Breithaupt*s Arsenic-glanee from Palm-
baum, near Marienberg; — has the aspect of native sulphide of antimony;
texture radiated; specific gravity 5*392; not very hard; contains 97 per
cent, arsenic and 3 per cent, bismuth. When once set on fire, it con-
tinues to bum till it is entirely consumed. (Weissenbach, J. techn.
Ckem, 10, 226; Kersten, /ScAtif. 53, 377; PogQ^ 26, 492.^ — a. Fourteen
parts of bismuth and one part of arsenic yield, when fused together,
an alloy which expands stronely in solidifying. — h. An alloy of about
3 parts bismuth and 1 arsenic does not expand in solidifying ; it has a
reddish-white colour, and imperfectly laminar fracture. (Marx, Schw.
58, 464.)—^. Bismuth, fused with arsenic for a considerable time, retains
only iV ^^ ^^^^ metal. (Bergman, Optuc, 2, 281.^ — d. The arsenide of |
bismuth which is precipitated on passing arseniuretted hydrogen gas
through bismuth-salts, gives off nearly all its arsenic on distillation.
(Berzelius.)
B. Arseniate of Bismuth-oxide. — Precipitated, on adding arsenic
acid to a solution of bismuth in nitric acid, in the form of a white, taste-
less, difficultly soluble powder (Scheele), which, when ignited with charcoal,
is resolved (according to Berzelius) into sublimed arsenic and bismuth
containing arsenic, and, according to Th6nard, is insoluble in water and i
in nitric acid, but soluble in hydrochloric acid. I
C. SuLPHABSENiTE OF BiBMUTH. — 2BiS', 3 AsS*. — Rod-brown preci- I
pitate, which turns black on drying, and yields a black-brown powder. i
Fuses readily, gives off tersulphide of arsenic when more strongly heated, \
and leaves a fused basic compound not further decomposible by heat. This j
compound, when solidified, nas a steel-grey colour, metallic lustre, and [
oiystalline fracture, and yields a grey powcler. (Berzelius.) t
D. SuLPHABSENiATB OF BisMUTH. — 2BiS', 3AsS\— Dark-brown^ i
soluble in excess of sulpharseniate of sodium. (Berzelius.)
Bismuth amd Antimony.
A. Antimonidb of Bismuth. — The two metals unite in all propor-
tions, and form a brittle alloy. The alloy containing equal parts of the
two metals expands strongly in solidifying ; that wnich contains 1 part
of bismuth with from 2 to 4 parts of antimony, expands less.
VOL. IV. 2 o
I
4fi0 BISMUTH.
B. SuLPHANTiMONTATE OF BiBMUTH. — Dark-brown precipitate. In
con£6queoco of the free f^ii i|i the bismath-solation, this oomponnd
cannot be obtained free from uncombined tersulphide of bismnth and
pentasnlphide of wtimonj, (RammeUborg,)
A. TbiiLubi^b of Bismuth. — The two metab niay be fdaed together
in all proportions. (Berielins.)
B. SuLPHOTBLLURiDE OF BiSMUTH.— 2BiTe*,BiS'. — Tellurte Bismuth;
Spiessglanz-nlber (Werner); JHfolffhdansilber (Mobs); Frianatoidal
Bismuth-glance (Wehrle) ; Ahomhohedral Bismuth-glance or TetradymUe
(Hardinger). — Primary form, an aonta rhombobedrop, Fig. \5\i also a
truncated obtuse rhombohedron, Fig, 142. (Breitbaupti Schw, 5%^ 170.)
The crystals result from th0 combination of the faces of two rbonibor
bedronsy more acnte than the acute primitiye rhombobedron, truncated
with p-faces. (Haidinger, Zeitschrift Fhy9. Math, 9, 130.) Specific
gravity, 7-807.. 8-44. (Wehrle), 7514 (Ba^nmgartner), Light lead-
grey, inclining to tin-white, with a high lustre. (Wehrle.)
Betidiiis. Wehrle.
SdieiiVlEHi.
3Bi ,..,.., , 639 .... ft9-66 58-30 ,.„ 60-0
^Te 384 ,.., 85-86 3605 ..,. 34'6
38 „„ 48 .... 4-48 , 4-32 .... 4-8
VO .*•«* ••.■••... •••• f....... ...t w8C0
M»tr» ,... 0-T6
"2BrTe»,BiS« lOTl .... 10000 ~„ 99-42 Z 99-4
When heated in a glass tube, it yields metalUc tellnriuni which sub-
limes in drops. Before the blowpipe it fuses readily, exhaling an odour
of sulphur and selenium ; bums with a bluish Qame \ forms a yellow filmy
with white border on the charcoal; and leaves a shining metallic globule,
which, on cooling, becomes covered with a reddish film: the reduced
metal is brittle, and has a granular fracture. The compound dissolyes
readily in nitric acid, depositing flakes of sulphur, (Wehrle, Schw, 59,
482: ZeUachr. Fhvs, Maih. 9, 133 and 144; ^hsir, Fogg, 21, 595 and
599.) The ore u-om St. Joz6, in Brazil, exhibit similar obaractexs*
(Von Kobell, J. pr. Chem, 8, 341,)
C. SuLPHOTELLUBTTE OF BisHiTTH. — A 0O|npound of PistUf>h{de of
Tellurium with Tersulphide of BismuUt. — Formed by precipitating a
bismuth-salt with sulphotellurite of sodium. — ^Dark-brown precipitate,
black when dry; gives oflT sulphur when distilled, and leay^ a grey
mass, baring the metallic lustre* (Berzelius.)
Otheb Cobcpounds of Bismuth.
With Tin, Lead, Iron, Nickel, Copper, Mercury, Silver, Gold, Plati-
num^ Palladium, and Bhodinmi forming easily fusible alloys.
EKD OF VOL, IV.
LONDON: rstKTXD BT HilUlIION AMD 80N| ST. MAKTUf'a LAKE.
CAVENDISH SOCIETY,
1850.
Artbub AiKpr, F.G.S.
Pbofbssob Bbajtbb, F.R.8.
Eabl ov Bublibcwon, F.Ril.
8iB Jambs Olabk, M.D., F.R.0.
Pbofbbsob T. Clabk, M.D.
MicHABL Fabapat, P.^.L., F.BA
Sib B. Kaw, M.I)., M.R.I.A.
ThB MaBQUU Of KOBVRAKFVOV, F.R.0*
RicHABD Phillips, F.R.8.
William Pbovt, M.D., F.R.0.
Jambs I^hompsoit, F.R.8.
PaorEssoB Wheatsto^b, F.Ril.
€0uticfT«
Jacob Bbi^l, F.C.S.
GoLBiHa Bibb, M J)., F.R.8,
Bbnjamiv C. Bbobib, F.R.8,
Wabbbn Pblabub, F,R.S,
W. Febotson, F.CB.
J. P. Gasbiot, F.R.8.
J. J. Gbipfin, F.CS.
A. W. BorMAVB, Pb J)., V.OM.
G. D. LoNosTAf F, M,P., F.O,S.
W. A. Miller, M.D., F.R.S,
T. N. R. MoRsoB, F.LA
JOHATHAN PerbibAi MJ).} F.R.S.
Lyon Platpair, PhJ>., F.R.8,
W. Shabpby, M.D„ F,R»8.
Robebt Wabinotov, F.0.0.
A. W. WiLLiAmov, PhJ)., F.OA
Bbhrt BiAFNQKT Ijmoir, VJ>.y F.R J., 8t. ThomM*6 So«pitd.
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