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2(C 4 H 5 0,CS 2 ) + KO,HO = C 4 H 5 KS 2 ,2CO 2 + C 4 H 6 S 2 .

5. An alcoholic solution of xanthic ether mixed with a similar solution of
sulphide of hydrogen and potassium solidifies in a few days, forming a
magma of xanthate of potash, mercaptan being produced at the same time.
Debus):

2(C 4 H 5 O,CS 2 ) + KS,HS = C 4 H 5 KO 2 ,2CS 2 + C 4 H 6 S 3 .

Xanthic ether is not altered by immersion in aqueous ammonia. ; but
when dry ammonical gas is passed into the alcoholic solution of the ether,
complete decomposition takes place after a while; the liquid which passes
over, on distilling the mixture, contains sulphide of ammonium and
sulphide of ethyl, while xanthamide (vid. p. 443) remains in solution.
(Debus):

2(C 4 H 5 0,CS 2 ) + 2NH 3 = C 6 H7NS 2 O 2 + NH 4 S + C 4 H 5 S.
Xanthamide.

7. Protochloride of mercury added to an alcoholic solution of xanthic
ether forms a white precipitate. Protoxide of mercury, peroxide of lead,
and protoxide of lead, produce no action, even with the aid of heat.
Chloride of calcium, protochloride of copper, and nitrate of silver, are
likewise without action on an alcoholic solution of xanthic ether. IF

8. Potassium and sodium do not act on xanthic ether in the cold,
and even on the application of heat, only a small quantity of gas is
evolved.

Combinations. Xanthic ether is quite insoluble in water.
It dissolves Iodine, forming a brown transparent oil.
It mixes in all proportions with Alcohol and Ether.



Bioxysulphocarbonate of Ethyl,
C 6 H 5 S 4 2 = C 4 H 5 2 ,C 2 S 4 = C 4 H 5 0,C 2 S 4 0.

DESAINS. N. Ann. Chim. Phys. 20, 469; abstr. Compt. rend. 23, 1089.
DEBUS. Ann. Pharm. 72, 1; abstr. Pharm. Centr. 1850, 117, 13.5;

Laur. & Gerh. C. R. 1850, 50; Cham. Gaz. 1850, 143; Jahresber.

1849, 419.

When iodine extracts the potassium from xanthate of potash,
C 4 H 5 K0 2 ,'2CS 2 , this compound remains behind. (Desains.) ^[ Similarly
with xanthate of lead. (Debus.)

According to Debus, it is probable that when protochloride of copper is heated
with xanthate of potash (a process whose ultimate product was regarded by Zeise as a



442 ETHYLEXE: PRIMARY NUCLEUS C<H<.

body having the composition of xanthic ether), a compound isoraeric with bioxysulpho-
carhonate of ethyl is formed ; for if after the alcoholic solution of xanthate of potash
has been treated with protochloride of copper, the liquid be separated by filtration from
the cuprous xanthate thereby formed, and the filtrate mixed with water, an oily body is
precipitated, which, though it does not crystallize even when its alcoholic solution is
cooled to 0, nevertheless agrees iu its other properties with bioxysulphucarbonate of
ethyl. 1

Preparation. 1. Iodine is added to an alcoholic solution of xanthate
of potash, so long as it does not colour the liquid permanently, and the
mixture is left to evaporate spontaneously in the air; it then, after a few-
days, deposits crystalline laminae, which may be freed from iodide of
potassium by washing with water. The compound is likewise precipitated
in the form of a white powder when alcoholic tincture of iodine is mixed
at ordinary temperatures with aqueous xanthate of potash, in such pro-
portion as to decolorize the tincture. In summer the compound can only
be obtained in the form of an oil, which must be washed with water, and
dried over chloride of calcium. (Desains.) TT According to Debus, the
alcoholic solution of xanthate of potash, after being treated with iodine,
may be immediately diluted with water, and left to itself at 12. If a
concentrated alcoholic solution of xanthate of potash be used, the com-
pound separates, on diluting the liquid with water, in the form of a yellow
oil, which in the course of a few hours solidifies in the form of a crystalline
mass. 2. The compound may also be obtained by treating xanthate of
lead suspended in water with iodine, till the liquid assumes a permanent
brown tint, adding more xanthate of lead to remove the excess of iodine,
mixing the clear colourless filtrate with an equal bulk of water, and
leaving it to itself for 10 or 12 hours at about ]2 J ; the compound then
crystallizes in small white prisms, which are easily freed from adhering
iodide of lead by recrystallization. (Debus.)

Properties. Bioxysulphocarbonate of ethyl crystallizes from dilute
solutions in concentric groups of white shining prisms reduced to tables.
At 28 (or at the heat of the hand, according to Desains) it fuses to a
yellowish oil, which has a peculiar odour (persistent, but not unpleasant:
according to Desains), and crystallizes again but slowly. After being heated
to 100.... 120 the liquid does not crystallize any more on cooling. (The
compound may also be at once obtained in the form of an uncrystallizable
liquid, if the temperature be raised too high during its preparation by a
too rapid addition of iodine.) At 160 3 , decomposition takes place. The
compound dissolves readily in absolute alcohol and in ether. (Debus.) IT









Desains.


Debus.


6 C


36


.... 29-75


29-1


2977


5 H


5


4-13


4-2


4-23


4 S


64


.... 52-90


53-5


53-50


2 O


16


.... 13-22


13-2


12-50













121 .... 10000 100-0 , .. 100-00



Decompositions. Between 200 and 210, only a small portion of the
compound distils over unaltered, the greater part being resolved into
eulphocarbonate of ethyl, carbonic acid and carbonic oxide gases, vapour
of sulphide of carbon, and a residue of sulphur. Equation, when carbonic
acid is produced:

2C 6 H 5 S 4 2 = 2CH fi S 3 + CO* + CS 3 + 2S ;



BIOXYSULPHOCARBONATE OF ETHYL. 443

Equation, when carbonic oxide is formed :

C 6 H 5 S 4 O 2 = C 5 H 5 S 2 O + CO + 2S.

Carbonic acid and carbonic oxide are always evolved together, the car-
bonic acid predominating. The residual sulphur has a blackish tint,
arising from the presence of a small quantity of carbonaceous matter.
As the sulphocarbonate of ethyl which passes over is still contaminated with a portion of
the undecomposed compound, its analysis gives 37*7 p. c. carbon and 6*1 hydrogen ; but
after the compound C 6 H 5 S 2 O 4 has been removed by a second distillation, the sulpho-
carbonate of ethyl gives by analysis 36'9 C and 6'6 H. (Desains.) IT Bioxysulpho-
carbonate of ethyl, subjected to dry distillation, begins to decompose at
130; and at 170, the decomposition is so rapid that the distillation may
be terminated without further application of heat from without. The gas
evolved in the decomposition is carbonic oxide mixed with small quantities
of carbonic acid and sulphide of carbon. The residue consists of sulphur.
The boiling point of the distillate varies from 50 to 210 J . When it was
heated for some time to 50, a small quantity of sulphide of carbon was
given off from it; on raising the heat to 140 J , scarcely anything
passed over; between 175 and 190, principally carbonate of sulphethyl
(p. 445):

C 6 H 6 S 4 O 2 = cs 2 + s + c 4 H 5 s,ca*.

between 190 and 200, but a small quantity of distillate was obtained;
between 200 and 210, xanthic ether (Debus). ^[ Oil of vitriol
decomposes the compound, even at ordinary temperatures, giving off
a large quantity of sulphurous acid; but hydrochloric acid may be dis-
tilled over it without alteration. (Desains.) Absolute alcohol saturated
with dry ammoniacal gas separates sulphur from the compound, and
forms a brown-red solution, which, when evaporated in vacuo, solidifies
in semicrystalline crusts containing 30'97 p. c. C, 6'6 H, and 140 N.
Ether dissolves a portion of these crusts, leaving undissolved a quantity
of white crystals containing 16*8 p. c. C and 5'8 H. The ethereal solution,
when evaporated, yields large flexible needles of another substance, con-
taining 34'0 p. c. C and 7'0 H. (Desains.) IT When dry ammoniacal
gas is passed into an alcoholic solution of bioxysulphocarbonate of ethyl,
the liquid soon rises in temperature and becomes turbid, from deposition of
sulphur; and if the passage of the gas be discontinued as soon -as the
separation of sulphur is at an end, the liquid then filtered, and the filtrate
evaporated to dryness in vacuo, an efflorescent residue is obtained, con-
consisting of small aggregated needles of xanthate of ammonia, saturated
with an oily body, which is Xanthamide:

2C f 'H 5 S 4 2 + 2NEL 3 = 2S + C 4 H 5 (NH 4 )0-,2CS 2 + C r> H?NS 2 O 2 .
Xanthate of ammonia. Xanthamide.

The xanthamide may be dissolved out by ether ; and on evaporating the
ether, it remains in the form of an oil having an alliaceous odour, and
gradually solidifying when cooled below 28. Dry ammoniacal gas passed
over dry bioxysulphocarbonate of ethyl at about 70 J , yields volatile pro-
ducts consisting of sulphide of carbon, sulphocarbonate, sulphocyanido,
and sulphide of ammonium, and a residue consisting of xanthamide,
sulphur, and the greater part of the sulphocyanide of ammonium. (Debus.)
When an alcoholic solution of bioxysulphocarbonate of ethyl is mixed
with an alcoholic solution of hydrate of potash, sulphur separates out, and
a solution is formed containing xanthate of potash, which, by filtration,



444 ETHYLENE: PRIMARY NUCLEUS C 4 H<.

concentration in vacuo, and cooling down to 0, is obtained in the crystal-
line state, and when purified by solution in alcohol, leaves a residue of
carbovinate of potash. The decomposition is represented by the following
equation:

4C G H 5 S 4 O 2 + 4KO = 3(CWK02CS2) + C 4 H 5 KOV2CO 2 + 4S.



Xanthate of Carbovinate of

potash. potash.

The carbovinate of potash is resolved into alcohol [ether?] and carbonate
of potash; part of the sulphur separates in the free state, and the rest is
converted by the potash into sulphide of potassium, and probably also
into hyposulphite of potash. (Debus.) Desains had previously observed that
potash added to an alcoholic solution of C r> HS 4 O' 2 , throws dowu sulphur and forms
xanthate of potash. When a saturated alcoholic solution of bioxysulpho-
carbonate of ethyl is mixed with sulphide of hydrogen and potassium,
sulphuretted hydrogen is given off, sulphur is precipitated, and xanthate
of potash remains in solution. (Debus.)

C fi H 5 S 4 2 + KS,HS = C 4 H 5 KO 2 ,2CS 2 + S + HS. H

Xanthomethylate of potash treated with a solution of iodine in wood-
spirit likewise yields an oil = C 4 H 3 S*0 2 , which is converted by distilla-
tion into the compound C 2 H 3 0,CS 2 , described by Cahours (VII. 393),



1[ Vinomethylic Oxysulphocarbonate.
C 8 H 8 2 S 4 = C 2 H 3 0,C 4 H 5 0,2CS 3 = C 2 H 3 0,CS 2 + C 4 H 5 0,CS 2 .

CHANCEL. Laur & Gerh. C. R. 1850, 403; Jahresber. 1850, 469.
Further: Compt. rend. 32, 587j Instit. 1851, 130; J. pr. Chem. 53,
111; Jahresber. 1851, 512.

Carlomethylovinide bisulfure, zweifach-geschwefeltes Carlomethylovinid.

Formed by distilling xanthate of potash with an equivalent quantity
of sulphomethylate of potash:

C 4 H 5 KO 2 ,2CS 2 + C 2 H 3 KO 2 ,2SO 3 = C 4 H 5 O,C 2 H 3 O,2CS 3 + 2(KO,SO 3 ).
Pale yellow, transparent liquid, of sweet taste, and strong, ethereal,
but not unpleasant odour. Sp. gr. 1-123 at 11. Boils at 179 without
decomposition. Vapour-density 4'652.

Chancel.



8 C


, 48


.... 35-29


35*7


8 H


8


5-88


6*0


2


16


11*77




4 S


64


47-06













C-'H 3 O,C 4 H 5 O,2CS 2 . 136 .... 100-00

Vol. Density.

C-vapour 8 .... 3-3280

H-gas 8 .... 0-5544

O-gas 1 .... 1-1093

S-vapow .... 4-4372

Vapour of C1I 8 S-O 1 .... 9'4289

2 , , 4-7144



This



CARBONATE OF SULPHETIIYL. 445



This compound may be regarded as vinomethylic carbonate C 2 H 3 0,
C 4 H 5 0,2C0 2 , in which 40 are replaced by 4S; also as xanthate of
methyl, C 4 H 5 Me0 2 5 2CS 2 , or xanthomethylate of ethyl, C 2 H 3 Ae0 2 ,2CS 2 .

Very inflammable and burns with a blue flame, giving off large quan-
tities of sulphurous acid. Ammonia decomposes it, forming xanthamide
and methylic mercaptan (VII, 284):

C 6 H'NO 2 S 2 + C 2 H^S 2 .



This decomposition is analogous to that of vinomethylic carbonate by ammonia,
the products of which are urethane and methylic alcohol : [C*H S O' ; + NH 3 = C 6 H7^O 4 +
C 2 H 4 O 2 ]. Xanthamide may in fact be regarded as bisulphuretted urethane, or urethane
in which 2O are replaced by 2S.

Vinomethylic sulphocarbonate is insoluble in water, but soluble in
alcohol and ether. (Chancel.)






f Carbonate of Sulphethyl. C*H'S,C0 2 .

DEBUS. Ann. Pharm. 75, 136; abstr. Jahresber. 1840, 465.

Obtained, together with xanthic ether and free sulphide of carbon, in
the dry distillation of bioxysulphocarbonate of ethyl (p. 443); also by
decomposing oxyxanthate of potassium (p. 461), with chloride of ethyl:

C*H 5 S,KS,2CO 2 + C 4 H 5 C1 = KC1 + 2(C 4 H 5 S,CO 2 ).

This latter reaction, however, yields but small quantities of the compound ; for it
takes place very slowly, and in the meanwhile the potassium -salt is for the most part
converted into carbonate of potash, sulphuretted hydrogen and alcohol [by the action
of atmospheric moisture ?].

Colourless liquid having an agreeable ethereal odour. Sp. gr. 1'032
at 1. Boils at 161-162. Insoluble in water; but easily soluble in
alcohol and ether.



5 C


30 ....


44-77


Debus.
44-21


5 H


5 ....


7-46


7-61


s


16


23-89


24'71


2 O


16 ....


23-88













C 4 H 5 S,CO 2 67 .... 100-00

Carbonate of sulphethyl is not acted upon by hydrochloric acid.
Sulphuric acid acts upon it only when heated; nitric acid, only when
strong and with the aid of heat. With an alcoholic solution of sulphide
of hydrogen and potassium, it forms oxyxanthate of potassium, C*H 5 KS 2 ,
2C0 2 , and mercaptan:

2(C 4 H 5 S,CO 2 ) + KS,HS = C 4 H 5 KS 2 ,2CO 2 + C 4 H fi S 2 .

With an alcoholic solution of hydrate of potash, it yields the same pro-
ducts together with sulphide of potassium. When the mixture of the
two liquids is set aside in a cool place, at a temperature of about 5, it
solidifies after awhile, if sufficiently concentrated, to a crystalline mass
consisting of C 4 H 5 KS a ,2C0 2 . At the bottom of the vessel there also col-
lects a clear, oily stratum containing well formed rhombic tables; this
oily liquid is a concentrated solution of carbonate of potash containing
crystals of the salt. The mother-liquid contains mercaptan and sulphide



446 ETIIYLENE : PRIMAttY NUCLEUS

of potassium. The hydrate of potasli first acts on the carbonate of cthylic
sulphide, forming sulphide of hydrogen and potassium, carbonate of
potash, and alcohol:

2(C 4 H 5 S,CO=) + 3(KO,HO) * KS,HS + 2C 4 H fi O 2 + 2(KO,CO 2 );



and the sulphide of hydrogen and potassium then acts on another poif on
of carbonate of sulphethyl in the manner above described. When
dry ammoniacal gas is passed into the alcoholic solution of carbonate
of sulphethyl, decomposition takes place; the liquid acquires the odour
of sulphide of ammonium, and when evaporated to the crystallizing
point, yields a salt in long, yellow needles, mixed with a colourless
gelatinous substance resembling precipitated silica. Both these bodies
dissolve readily in water and alcohol, and cannot be separated by crys-
tallization; their aqueous solution forms black precipitates with lead,
copper, and mercury salts. Carbonate of ethylic sulphide may be
boiled with mercuric oxide without decomposing.



IF Bicarbonate of Bisulphethyl. C 6 H 5 S 2 0*=C 4 H 6 S 2 ,2C0 3 .

DEBUS. Ann. Pharm. 75, 142; Jakresber. 1850, 466. Further: Ann.
Pharm. 82, 253; Jakresber. 1852, 563.

Formed by the action of iodine on oxyxanthate of potassium:
C 4 H 5 S,KS,2CO 2 + I = KI + C 4 H 5 S 2 ,2CO 2 .

Preparation. Iodine is added to an alcoholic solution of C 4 H 5 KS 2 ,
2C0 3 , till the liquid exhibits a brown colour; after which the excess
of iodine is removed by adding a little more of the potassium-salt.
The liquid is then diluted with twice its bulk of water, whereupon the
compound C 4 H 5 S 2 ,2C0 2 separates in the form of a colourless oil, which
must be washed several times with water and then dried in vacuo. The
mother-liquor contains nothing but iodide of potassium.

Properties. Colourless, strongly refractive, oily liquid, which makes
greasy spots on paper. It is heavier than water.

Debus.



6 C


24


.... 34-28


34-67


34-73


5 H


5


4-76


4-70 .


4-71


2 S


32


30*48






4 O


32


30-48

















C"H*SO 4 93 .... 100-00

Decompositions. 1. This compound heated in a tube, first gives off
gas-bubbles and an ethereal substance having an agreeable odour; then
becomes gradually more viscid, acquires a deep yellow colour, and gives
off a pungent vapour. On cooling, nearly the whole residue solidifies in
a iilphur-yellow, amorphous mass. 2. Sulphuric and nitric acid mix
with the compound at ordinary temperatures without decomposing it,
decomposition not taking place till the liquid is boiled. 3. Potash acts
upon the alcoholic solution of this compound in the same manner as on






BICARBONATE OF BISULPHETHYL. 44?

hioxysulphocarbonate of ethyl, forming oxyxanthate of potassium,
C 4 H 5 KS 2 ,2L O 2 , sulphide of potassium, and free sulphur. Protochloride
of mercury, bichloride of platinum, and acetate of lead form no precipi-
tates with it. 4. Strong ammonia poured upon the compound decom-
poses it immediately, with separation of sulphur. The liquid filtered
from the sulphur, after sufficient addition of ammonia, if concentrated
over the water bath and then over sulphuric acid, yields almost simul-
taneously, crystals of two or three different substances, and a white
flocculent body, which have not yet been satisfactorily investigated. (One
of the above-mentioned substances exhibited the form and characters of
urethane; another, which crystallizes in prisms; dissolved readily in
water and in alcohol; had a neutral reaction; was not altered by chloride
of platinum, sulphate of copper, or acetate of lead; did not give off
ammonia when treated with potash; fused when heated; and was after-
wards resolved into a volatile liquid and a white, solid, sublimable
body.) When ammoniacal gas is passed into the alcoholic solution of
C 6 H 5 S 2 0*, similar crystal lizable products of decomposition are formed in
small quantity. Debus regards it as probable that in these decomposi-
tions, i.e., in presence of water, the compound C 6 H 5 S 2 4 is for the most
part resolved into alcohol, carbonic acid, and sulphur. When dry
ammoniacal gas was passed into a solution of the compound dissolved in
a four or fivefold quantity of ether, the liquid rose in temperature and
suddenly became turbid, the odour of ammonia disappearing and sulphur
being separated; and this action was repeated several times. On filtering
the liquid after the decomposition was completed, and expelling the ether,
ammonia, and sulphide of ammonium, by heating it to 100, a yellow oil
and small white crystals separated out; the former dissolved readily in
ether, the latter with difficulty. The crystals, when purified by recrys-
tallization from boiling alcohol, proved to be the allophanate of ethyl
C e H 8 N 2 O 6 C 4 H 5 0,C 4 H 3 N 2 5 , discovered by Liebig and Wbhler. (Ann.
Phurm. 59, 291.) The mother-liquor still contained a neutral body
which crystallized in needles, and an amorphous body. The yellow oil
easily soluble in ether had an unpleasant odour, was heavier than water,
sparingly soluble in alcohol, insoluble in water, had a neutral reaction,
and gave by distillation a volatile stinking oil, while sulphur was
separated and a black carbonaceous mass remained behind. Debus
regards this oil as a sulphide of ethyl. For the decomposition of the
compound C 6 H 5 S 2 4 in the state of ethereal solution by ammonia, he gives
the following equation:

2C G H 5 S 2 O 4 + 2NH 3 = C 8 H 3 N 2 O 6 + C 4 H 5 S + 2S + HS + 2O.
Allophanic ether.

Combinations. Bicarbonate of bisulphethyl is insoluble in Water, but
is readily dissolved by alcohol and ether. Its solubility in alcohol dimi-
nishes with the proportion of water contained in the alcohol; absolute
alcohol mixes with it in nearly all proportions; but spirit of 40 per cent,
takes up but small quantities of it. (Debus.)



Bicarbonate of Bisulpli ethyl with Bicarbonate of Sulphethyl. C 4 H S S 2 ,
4 H 6 S,2Cb 2 =C 12 H 10 S 3 8 . Formed by the decomposition of oxy-
xanthate of copper (md. p. 464) ;

5(C4H 5 CuS 2 ,2C0 2 ) = [3(C 4 H 5 CuS 3 ,2CO-) + Cu'S] +



448 ETIIYLENE : PRIMARY NUCLEUS C<H.

By collecting the unctuous mass produced by this decomposition on a
filter, washing it with water, then dissolving in cold alcohol, evaporating
the filtered alcoholic solution in vacuo, digesting the dry residue in ether,
and leaving the ethereal solution to evaporate in the air at ordinary
temperatures, the compound C 12 H 10 S 3 8 is obtained in the form of an oil,
having a faint yellowish green colour, arising from a small quantity of the
copper-compound 3(C 4 H 5 CuS 2 ,2C0 2 ) -fCu 2 S, which, not being quite inso-
luble in ether, becomes mixed with it. This impurity is easily removed
by agitation with dilute hydrochloric acid. The compound, after being
washed in water and dried in vacuo, forms a colourless, strongly refracting
liquid, which cannot be distilled, because it is resolved by heat into other
ethereal compounds and a yellow crystalline substance, probably sulphur.
Heated with alcoholic potash, it yields sulphur, carbonate of potash,
and a salt, which from its physical and chemical properties, appears to
l)e oxyxanthate of potash (p. 461). Hydrochloric acid exerts no action
on the compound. Nitric acid does not affect it at ordinary tempera-
tures; but, on the application of heat, decomposes it, with evolution of
nitric acid. (Debus.)

Debus.



12 C


72


.... 37-11 ....


.... 36-98




10 H


10


5-15


5-17




3 S


. . 48


.... 24-75 ..


. . 27-95


25-28


8 O


04


.... 32-99

















,2CO 2 194 .... 100-00
Might also be regarded as a quadrocarbonate of sesquisulphethyl : (C 4 H 5 ) 3 S 2 ,4C0 2 . ^.

Xanthic Acid, C 4 H 6 2 ,2CS 2 .

ZEISE. Sdiw. 36, 1; 43, 160. Pogg. 35, 457.

COUERBE. Ann. Chim. Phys. 61, 225; abstr. /, pr. Chem. 23, 83.

Ann. Chim. Phys. 68, 170. Rev. scientif. 3, 11; also J. pr. Chem.

23, 94.

Xanthons'dure, Xanthogens'dure, Xanthins'dure (from its property of forming
yellow precipitates with copper salts), Acide xanthique, sulphocarbonique, sulfocar-
bethenique. Discovered and examined by Zeise in 1822.

Formation. Sulphide of carbon, mixed with alcohol and potash,
forms water and xanthate of potash :

KO + C 4 H G O 2 + 2CS 2 = C 4 H 5 KO 2 ,2CS 2 + HO.

When this salt is decomposed by an aqueous acid, xanthic acid separates
out. (Zeise.)

C 4 H5K0 2 ,C 2 S 4 + HO,S0 3 = KO,SQ3 + C 4 H B 2 ,C 2 S 4 .

Preparation, Xanthate of potash is placed in a glass cylinder, cooled

to from without, and a mixture of 1 pt. oil of vitriol and 5 pts.

water (hydrochloric acid may also be used,) is poured upon it till the acid

. -ibly in excess; the mixture is then .shaken up a little, the milky

liquid mixed a few seconds afterwards with an equal bulk of water, and




XANTHtC ACID. 449

then with a much larger quantity. Too much water, however, exerts a
decomposing action on the finer and still disunited particles of the acid.
As soon as the oily xanthic acid has settled down, and the watery
liquid has become clear, the latter is decanted from the oil by means of
a pipette, and fresh water repeatedly poured on the oily acid and off
again, till it no longer forms a cloud with chloride of barium. Lastly,
the remaining portion of water, which would exert a decomposing action,
is removed, first by the separating funnel, and then by placing the acid
over chloride of calcium; and the acid is preserved in a well stoppered
bottle, placed in a very cool situation. (Zeise.)

Properties. Transparent, nearly colourless oil; heavier than water;
very volatile. Reddens litmus paper distinctly, but the red tint quickly
changes to yellowish white. Has a strong and peculiar odour like that
of sulphurous acid; its taste is astringent and somewhat acid at first, but
afterwards becomes somewhat bitter and burning. Very inflammable;
precipitates copper-salts yellow. (Zeise.)

Calculation, according to Zeise.




6 C


36


29-51


6 H


6 ....


4-92


4 S


64


52-46


2O


. 16


13-11









C 4 H 6 O 2 ,C 2 S 4 122 .... 100-00

Therefore, 1 At. alcohol +2 At. sulphide of carbon, or 1 At. water, 1 At. ether,
and 2 At. sulphide of carbon = HO, CS 2 + C 4 H 5 O,CS 2 . Xanthic acid is carbovinic acid
(p. 394), in which the oxygen of the carbonic acid is replaced by sulphur.



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