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decomposition. It reduces silver salts and Fehling's solution
in the cold, and gives a green colouration with ferric chloride,
which is converted into a reddish violet by the addition of a
little ammonia or carbonate of soda.

Homocatechol monomethyl ether or Greosol, C C H 3 (CH 3 )(OCH 3 )
OH(1 : 3 : 4), occurs in beech wood -tar-creosote and in the pro-
ducts of distillation of guaiacum resin. 2 In order to prepare
it, the portion of creosote boiling at about 220 is dissolved in
ether and treated with very concentrated alcoholic potash ; potas-
sium creosate, C 8 H 9 K0 2 + 2H 2 O, separates out in needles and is
then decomposed by dilute sulphuric acid. It may also be
prepared by heating a-homovanillic acid, C 6 H 3 (OH)(OCH 3 )CH 2 .
CO 2 H, with lime (Tiemann and Nagai). It is a strongly re-
fractive liquid boiling at 220, and possesses a feeble odour which
resembles that of vanilla and is very pleasant when the vapour
is dilute. It produces a metallic mirror when warmed with a
solution of a silver salt, and its alcoholic solution is coloured
emerald-green by ferric chloride. Phosphorus chloride converts
it into parachlorometacresol methyl ether, C 6 H 3 C1(CH 3 )OCH 3 ,
(CH 3 : OCH 3 : 01=1 : 3 : 4), a liquid boiling at 185 . 3

Homocatechol dimethyl ether, C 6 H 3 (CH 3 )(OCH ;} ) , also occurs in
creosote, and is obtained pure by boiling. potassium creosate with
methyl iodide and wood-spirit. It is a liquid which boils at
214 215 and possesses the characteristic smell of the indif-
ferent oils which are obtained from crude wood -tar. It is
insoluble in water and alkalis, and is not coloured by feme
chloride. 4

2035 Oreotate was discovered by Reichenbach in the year
1832, both in the tar and the pyroligneous acid obtained by the
distillation of beech-wood. 5 He describes it as a colourless,
strongly refractive liquid, which begins to boil at 203 and
possesses an unpleasant penetrating odour, at the same time
resembling that of smoked meat, and a burning taste. He
investigated its properties very carefully, and found that it

* Tiemann and Nagai, Bcr. Deutsch. Chem. Ges. x. 210.

- Hlasiwetz, Ann. Chem. Pharm. cvi. 339
3 Biechele, ibid. cli. 115.

Tiemann and Mendelsohn, Ser. Deutsch. Chem. Ges. viii. 1136.

" Schweiger's N. Jahrb. Chem. Phys. vi. 301, 345 ; vii. 1, 57 ; viii. 57, 399.


coagulates albumin, and that fresh meat which has been soaked
in creosote for half an hour to an hour can be dried without
undergoing putrefaction. Such meat is very tasty, and
Reichenbach therefore concluded that creosote is the antiseptic
principle contained in ; smoke. He derived its name from this
power of preserving meat, its most peculiar and most striking pro-
perty, one too which had been known from the earliest times ; he
remarks, " The Greek word icpeas, meat, has a genitive Kpearo*;,
or Kpeaox;, contracted to /cpeax; ; o-co&> signifies to preserve, or
save; the two may be etymologically united in the word
creosote, which expresses meat-preserving or decay-saving-."

Very soon after this, Runge discovered carbolic acid, and
Laurent phenyl hydrate, in coal-tar, the identity of these bodies
being recognised somewhat later. No clear views, however, were
held as to the relation existing between phenol and creosote, and
a confusion arose which was maintained for many years with an
obstinacy unparalleled in the annals of our scienc'e.

Runge and Laurent showed that creosote, in spite of many
similarities, is quite a different substance from the compound
obtained by them. Phenol differs from creosote more especially
in being an acid, in possessing a different boiling-point, in
crystallizing when cooled, and in its different behaviour towards
chlorine, bromine, and nitric acid. Runge- moreover adds that it
imparts to' meat preserved by it an abominable taste.

Reichenbach, nevertheless, considered carbolic acid to be
identical with his creosote, the more so as he thought that he
had also discovered it in coal-tar and bone-oil.

Gmelin was also of this opinion ; according to him, carbolic
acid, phenyl hydrate, and creosote, are chemically identical, dif-
fering only in degree of purity. Gmelin' s views found universal
acceptance ; crystallized carbolic acid soon came into the market
under the name of creosote and displaced the genuine substance
obtained from wood-tar.

Gorup-Besanez, who had some of the latter body, which had
been prepared by Reichenbach at Blansko, in Moravia, at his
disposal, compared it with " crystallized creosote," and, like
Runge and Laurent, found them to be completely different; the
amount of substance in his possession, however, did not admit of
a close investigation.

Some years later, Batka supplied him with fresh samples of
creosote from Blansko, and he found that when acted upon by
nitric acid, no picric acid was formed, while potassium chlorate



and hydrochloric acid, instead of giving chloranil, C 6 C1 4 O 2 , gave
a similar substance, which, however, contained hydrogen. 1

These results, however, attracted but little attention ; Gmelin,
indeed, mentions them in his hand-book, but only to add that
Gorup-Besanez, to prove that creosote is a distinct substance,
ought to have prepared it himself instead of investigating a
commercial product.

Two years later, Gorup-Besanez published a more extended
treatise on creosote ; his determination of its composition agreed
with that of Ettling, who had analysed a specimen sent by
Reichenbach to Liebig.

By the action of chlorine he obtained pentachloroxylone,
C 13 H 7 C1 6 O 3 , and hexchloroxylone, C 13 H 6 C1 6 O 3 , substances
which were very similar to the chlorinated quinones obtained
by Stadeler. 2

About the same period Volkel published a paper on the
distillation products of wood, in which he relates his investi-
gation of the creosote obtained from the tar in a pyroligneous
acid works at Solothurn. He purified it by repeated solution in
caustic potash, precipitation with sulphuric acid and distillation.
The liquid, after purification in this manner, boiled at 202
208, and in its general properties resembled Reichenbach's
compound, but had a different composition, as the following
results of the analyses conducted by Ettling, Gorup-Besanez,
and Volkel show : 3

Creosote from Blansko. Creosote from Solothurn.
(Mean of 8 Analyses.) (Mean of 3 Analyses.)

Carbon 75 -21 72'45

Hydrogen 7-90 7- 10

Oxygen 16'89 20'45

100-00 100-00

Deville had previously analysed creosote prepared by Pelletier,
and obtained numbers only differing slightly from those of

Volkel considered that Gorup-Besanez had not purified his
creosote sufficiently, whereupon the latter treated it repeatedly
by Volkel's method, without, however, altering the results
obtained by analysis to any appreciable extent. 4

In the same year, Williamson published the results of an


investigation made byFairlie to wards the solution of the question
whether coal-tar creosote consists chiefly of carbolic acid ; he
thus discovered the homologue of phenol, cresyl hydrate or
cresol, which boils at 203, or at nearly the same temperature
as creosote, thus introducing a new source of confusion. The
research had no direct bearing on the real issue.

A new chapter in the history of creosote begins with Hlasi-
wetz's investigation " On Beech- Wood Tar Creosote and the
Products of Distillation of the Guaiacum Resin." He had
already obtained the compound C 8 H 10 2 from the creosote
from Blansko, and now found it in the distillation products of
guaiacum resin, together with its lower homologue, guaiacol,
C 7 H 8 O 9 , which Deville and Pelletier had already obtained from
the same source ; he therefore called his compound creosote-
guaiacol or creosol.

Hlasiwetz concluded that creosote is a kind of ether of the
latter, and probably contains the radical C 9 H U , thus simply
explaining the fact that it contains more carbon than creosol.

In the following year Duclos published a paper on cresyl
alcohol, which he had not only found in coal-tar, but also in the
tar from the gas-works at Giessen where only wood, and for the
most part fir-wood, was used. 1

In criticism of this paper, Gorup-Besanez observed that these
results were in opposition to all the facts known concerning
the distillation products of wood, in which no phenols had yet
been found. If Duclos' results were to be accepted, it would be
necessary to assume that fir-wood yields different products from

In the meantime Gerhardt calculated the formulae of the
chlorinated xylones as C 8 H 5 C1 3 O 2 and C 8 H 4 C1 4 O 2 , according to
which they appear to be homologues of the chloroquinones, thus
confirming Hlasiwetz' s results ; Gorup-Besanez then undertook
the reinvestigation of these compounds, but could not obtain
any creosote from Blansko ; this source had failed.

In the year 1864, Hugo Miiller made an important addition
to the history of creosote ; he investigated a sample which had
been prepared in London from Stockholm-tar and appeared to be
identical with that from Blansko. By treating it with hydriodic
acid be obtained methyl iodide and homocatechol (p. 31).

These different researches afforded a complete proof that
wood -tar creosote has nothing in common with coal-tar creosote.
1 Ann. Chcm. Pharm. cix. 135.

D 2


The only obstacles now remaining to a complete concordance of
opinion on the subject were Reichenbach's statement, which he
had never confirmed, that his creosote is contained in coal-tar,
and that of Duclos that wood-tar contains phenols, which no one
else had been able to detect.

2036 The creosote question seemed to have received a final
answer, but it was nevertheless not yet settled. In the year
1865, A. E. Hofmann investigated several commercial products
which he obtained from various firms as genuine beech-wood-
tar creosote, and found that they consisted chiefly of phenol.
Being unacquainted with the researches of Hlasiwetz and
Mliller, he called the existence of creosote in question and con-
cluded that it was nothing but impure phenyl hydrate, the
chlorinated xylones being mixtures of chloranil with chlorinated
phenols. The name of creosote ought, therefore, to be removed
from our list of chemical compounds, though this would not
prevent its use as a commercial term.

Gorup-Besanez replied to this by pointing out that Hofmann
had only proved a fact which had long been known, that phenylic
acid was often sold under the name of creosote. It was im-
possible that the firms' mentioned by him could have sent
him genuine creosote, because this article had long disappeared
from the German market. 1

This incident had a fortunate conclusion both for Gorup-Besanez
and for the facts. Fresenius corrected his statement, pointing out
that the " Verein fur chemische Industrie " at Mayence worked
up beech-wood-tar for creosote. The investigation of this showed
that it differed from the Blansko samples, but was probably
identical with those from Solothurn. Gorup-Besanez succeeded
in extracting from it a considerable quantity of guaiacol together
with a smaller amount of creosol ; by the action of potassium
chlorate and hydrochloric acid on the crude creosote he ob-
tained tetrachloroguaiacone, C 7 H 2 C1 4 O 2 , and tetrachlorocreosone,
CgH 4 Cl 4 2 , homologues of chloranil. When he treated creosote
with hydriodic acid, he obtained methyl iodide and catechol,
which were undoubtedly derived from the guaiacol. He assumed
that catechol is the lower homologue of guaiacol and creosol,
both of which yield chlorine products homologous with chloranil.

He concluded from his analysis that Rhenish creosote contains
the radical C 3 H 5 . 2

1 Journ. Prakt. Chcm. xcvii. 63.
8 Ann. Chem. Pharm. cxliii. 129.


Marasse opposed this view ; Gorup-Besanez had thought that
the fraction boiling between 199 and 208 is the allyl ether of
guaiacol, the latter being derived from it by the action of caustic
potash. If this were the case, allyl alcohol or some similar com-
pound must be simultaneously formed, whereas no one had
hitherto observed this. Guaiacol, he continues, may be the
methyl ether and not the homologue, of catechol, bearing the
same relation to it as creosol to homocatechol. The difference
between the composition of creosote and that of the two methyl
ethers contained in it is easily accounted for on the supposition
that it contains substances which boil at the same temperature
as guaiacol and creosol but are richer in carbon and poorer in

He also found that creosote contains, besides ordinary phenol,
its homologues cresol and phlorol, which yield the chlorine pro-
ducts now known as tetrachlorotoluquinone and tetrachloro-
xyloquinone. 1

The composition of creosote is very variable. Brauniger
found in one sample only traces of phenol and less than 2 per
cent, of cresol, and in that investigated by Gorup-Besanez only a
little cresol and still less phlorol, 2 while Tiemann and Mendelsohn
found large quantities of the latter. 3 The relative amounts of
guaiacol and creosol are also subject to great variations ; thus
Biechle found scarcely any creosol in a second sample of Rhenish
creosote obtained by Gorup-Besanez. 4

The higher boiling fractions contain, moreover, the dimethyl
ethers of homocatechol, pyrogallol, dimethylpyrogallol, and
propylpyrogallol, which have already been partially described.

The presence of phenols in wood-tar-creosote shows that it is
more closely related to the so-called coal-tar creosote than was
previously supposed. The latter differs from the former by the
absence of guaiacol, creosol, and the dimethyl ethers just men-
tioned. These must be derived from the characteristic aromatic
compounds which various chemists have discovered in wood
(Vol. III. Pt. II. 2nd Edition, p. 705).

ORCINOL, 6 H 3 (CH 3 )(OH) 2 (1 : 3 : 5).

2037 Robiquet discovered this compound in 1829 in Vario-
laria dcalbata, and named it orcin, because this lichen hail

1 Ann. CJiem. Pharm. clii. 59. s Ibid, clxxxv. 339.

3 Bcr. Dcutsch. Chcm. Gcs. x. 59. 4 Ann. Chem. Pharm. cli. 104.


formerly been called Lichen orcina, and because the name serves
as a reminder that the lichen is used for the preparation of
archil (orscille). 1

Orcinol was then further investigated by various other chemists, 2
from whose analyses Gerhardt first calculated its correct formula, 3
his result being confirmed by the researches of Stenhouse. 4

Orcinol occurs in the free state in all the lichens, the various
species of Rocdla, Lecanora and Variolaria, which are em-
ployed for the preparation of archil and litmus, and is a
decomposition product of various acids and ether-like bodies
prepared from these lichens. When these compounds are
heated with an alkali or submitted to dry distillation, orcinol is
formed, e.g :

Erythrin. Oi'sellinic Acid.

C 7 H 6 (01I) 2 C0 2


+ C 4 H 6 (OH) 4 .

Lccanoric Acid.

C,,H 6 (OH) 2 CO.O.C 7 H 5 (OH).C0 2 H + H 2 O

Orsclliuic Acid.

= 2C 7 H 5 (OH) 2 C0 2 H.

Orsellinic Acid. Orciuol

C 7 H 5 (OH) 2 C0 2 H = C 7 H (OH) 2 + CO 2 .

In order to prepare orcinol, 6 parts of JRocella fnciformis are

macerated for twenty minutes with 60 parts of milk of lime con-

taining 1 part of lime, the mass filtered and the erythriii pre-

cipitated from the filtrate by hydrochloric acid ; this is boiled

for half an hour with a slight excess of milk of lime, the solu-

tion filtered, treated with carbon dioxide to remove the excess of

lime, and evaporated nearly to dryness. The orcinol is extracted

rom t the residue by benzene, while erythrol is left behind. When

e benzene solution is shaken with water, the orcinol is taken up

J latter and is obtained pure on evaporation.* The crude

Phys. xlii. 236.

^5^^ HO; Liebig and wm > ** xxvii -

4 , m - Chim - 184> 5. 287.

I J? V mm - 1848 ' 63 J 1349,393.
s btenhouse.


orcinol can also be purified by distillation, 1 which is best carried
on in vacua?

Vogt and Henninger first prepared orcinol from toluene, by
chlorinating toluene in presence of iodine, and warming the
chlorotoluene with two to three times its weight of sulphuric
acid on the water-bath ; two sulphonic acids are thus formed,
which readily admit of separation, the barium salt of the one
being much more soluble than that of the other, which yields
orcinol when fused with caustic potash. 3

The chlorotoluene obtained by the method described is a
mixture of parachlorotoluene with a little orthochlorotoluene ;
since, however, the side chains of orcinol are arranged symmetri-
cally, an intramolecular change must take place during its
preparation just as in that of resorcinol from benzeneparidi-
sulphonic acid.

Neville and Winther obtained orcinol by fusing symmetric
bromotoluenesulphonic acid, the toluenemetadisulphonic acid
obtained from or thotoluidinedisul phonic acid, or bromometa-
cresol with caustic potash ; they also prepared it by heating
rnetadibromotoluene to 280 300 with caustic potash and a
little water, and finally by replacing the amido-group of amido-
metacresol by hydroxyl. 4

Orcinol is also formed, together with parahydroxybenzoic acid,
when aloes are fused with caustic soda. 5

Properties. Orcinol is readily soluble in water, alcohol, and ether,
and crystallizes with one molecule of water in six-sided monoclinic
prisms, which effloresce gradually over sulphuric acid, and more
rapidly when heated to 100. It is almost completely precipi-
tated in fine needles when its concentrated solution is warmed
with a saturated solution of common salt (Lamparter) ; it reduces
ammoniacal silver solution, has an intensely sweet but unpleasant
taste, and melts in the anhydrous state at 10C'5 108 (Neville
and Winther). When rapidly heated, it distils almost without
decomposition between 287 and 290 (Dumas). Ferric chloride
produces a violet-black colouration, and bleaching powder a dark
red, soon changing to yellow. In the presence of ammonia and
air it is converted into orcei'n, the colouring matter of archil,
and becomes coloured a deep reddish violet (Robiquet). Its

1 Lamparter, Ann. CJtcm. Pluirm. cxxxiv. 215.

2 De Luynes, Ann. Chim. Phrs. [4] vi. 184.

3 Ann. L'hcm. Plmrm. clxv. 366 ; Hull. f>oc. Chim. xxi. 373

4 Her. Dcutsi-h Chem. Gcs. xv. 2976.

5 Barth and Hlasiwctz, Ann. Chcm. Pharm. cxxxiv. 288.


alkaline solution when heated with a little chloroform becomes
coloured first purple-red and then bright red, and on dilution
with water has an intense greenish yellow fluorescence, homo-
fluorescein, C. 23 H 18 O 5 , being formed. This reaction is so delicate
that the compounds which yield orcinol can readily be detected
in the lichens by its means. A few pieces are boiled with 5 per
cent, caustic potash and a little chloroform added to the clear
solution ; it is then warmed for ten minutes on the water-bath
and diluted. 1

Orcinol may be quantitatively determined by adding standardized
bromine water to the dilute solution until tribromorcinol is no
longer precipitated and determining the excess of bromine by a
solution of potassium iodide. 2

Orcinol monomethyl ether, C 6 H 3 (CH 3 )(OCH 3 )OH, is formed,
together with the dimethyl ether, when orcinol is boiled with
caustic potash, methyl iodide, and wood-spirit. It is a light
yellow, oily liquid which boils at 273 and is soluble in alkalis.

Orcinol dimethyl ether, C 6 H 3 (CH 3 )(OCH 3 ) 2 , is a yellowish,
mobile fluid which boils at 244, is insoluble in alkalis, and is
converted by oxidation into symmetric dimethoxybenzoic acid,
or dimethyl-a-resorcylic acid, C 6 H 3 (OCH 3 ) 2 C0 2 H(5 : 3 : 1), thus
establishing the constitution of orcinol. 3

Orcinol ficetate, C 6 H 3 (CH 3 )(OC 2 H 3 0) 2 , is obtained by the action
of acetyl chloride on orcinol, and crystallizes from alcohol in
needles melting at 25. 4

Orcinol dicthylcartonate, CeH 3 (CH 3 )(O.COOC 2 H 5 ) 2 , is obtained
by the action of chlorocarbonic ether on the potassium compound
of orcinol, and is a thick, oily liquid boiling at 310 312 . 5

Orcvnolazobenzene, C 6 H 5 N NC 6 H 2 (CH 3 )(OH) 2 , is formed when
orcinol and diazobenzene nitrate are brought together in aqueous
solution. It crystallizes from a mixture of acetic acid and acetic
ether in dark red needles melting at 183 . 6

Schwarz, Per. DeutscJi Chem. Ges. xiii. 543.

Reymann, ibid. viii. 790.

Streng and Tiemann, ibid. xiv. 1999.

Luynos and Lionet, Zeihchr. Chem. 1867, 561.

Wallach, Ann. Chem. Pharm. ccxxvi. 86.

Typke, Ber. Deutsch Chem. Ges. x. 1579.



2038 These are obtained by the same methods as the cor-
responding resorcinol compounds, which they resemble very



Trichlororcinol, 1 C 6 C1 3 (CH 3 )(OH) 2 , long needles 123
Pcntachlororcinol, 2 C 6 C1 5 (CH 3 )O 2 large prisms 120' 5


Monobromorcinol, 3 C 6 H 9 Br(CH 3 )(OH) 2 , crystals 135

Dibromorcinol, 4 C 6 HBr 2 (CH 3 )(OH) 2 , needles 146

Tribromorcinol, 5 C 6 Br 3 (CH 3 )(OH) 2 , needles 98

Pentabromorcinol, 6 C 6 Br 5 (CH 3 )O 2 triclinic crystals 126


Mono-iodorcinol, 7 C 6 H 2 I(CH 3 )(OH) 2 , prisms 80'5

Tri-iodorcinol, 8 C 6 T 3 (CH 3 )(OH) 2 , brown tablets


{golden }
lustrous V 120
needles )
C dark ^

0-Nitro-orcinol, C 6 H 2 N0 2 (CH 3 )(OH).J yellow V 115

(needles J
f deep ]

a-Dinitro-orcinol, 10 C 6 H(NO 2 ) CH 3 (OH) 2 ,^ yellow [ 164-5

( tablets J

J Stenhousc, Proc. EOJI. Soc. 1871.

Stenhouse, Dittlerand Liebennann, Ann. Chcm. Pharm. clxix. 265.

Lamparter, loc. tit. * Tieinann and Streng, loc. tit.

Stenhouse and Groves, Journ. Chsm. Soc. 1880, 402.

Stenhouse and Rammelsberg ; Dittler and Liebermann, loc. tit. 255.

Stenhouse, Proc. B<n/. Soc. xxii. 53.

Stenhouse, Journ. Chcm. Soc. 1864, 327.

Weselsky, Bcr. Dcutsch. Chcm. Gc*. vii. 441.
10 Stenhouse and Groves, Journ. Chcm. Soc. 1877, i. 548.


( golden


/9-Diintro-orcinoVC 6 H(N0 2 ) 2 CH 3 (OH) 2 ^ yellow U09 110

(needles J
( long \

Trinitro-orcinol, 2 C 6 (N0 2 ) 3 CH 3 (OH) 2 , 1 yellow 163'5

(needles )

2039 Archil. This name was formerly employed to designate
both the colouring matter which is extracted from the lichens
just mentioned, and the lichens themselves. Theophrastos and
Dioscorides mention a plant <f)v/co<s 6a\dcr(n,ov or TTOVTCOV, called
by Pliny Fucus tnarinus, which is not a sea-weed, as the name
might be taken to imply, but a lichen which grows on the rocks
of certain islands, especially Crete, and is capable of dyeing wool
a beautiful violet or purple colour.

Archil came into the European market as early as the four-
teenth century ; the following account of it is given by Beck-
mann : 3

Among the oldest and principal Florentine families is that
known under the name of Oricellarii or Rucellarii, Ruscellai or
Rucellai, several of whom have distinguished themselves as
statesmen and men of letters. This family are descended from
a German nobleman named Ferro or Frederigo, who lived in the
beginning of the twelfth century. One of his descendants in
the year 1300 carried on a great trade in the Levant, by which
he acquired considerable riches, and returning at length to
Florence with his fortune, first made known in Europe the art
of dyeing with archil. It is said that a little before his return
from the Levant, happening to make water on a rock covered
with this lichen, he observed that the plant, which was then
called respio or respo, and in Spain crciglia, acquired by the
urine a purple, or, as others say, a red colour. He therefore
tried several experiments, and when he had brought to perfection
the art of dyeing wool with this plant, he made it known at
Florence, where he alone practised it for a considerable time to
the great benefit of the state. From this useful invention the
family received the name Oricellarii, from which at last was
formed Rucellai.

1 Leeds, Ber. Deutsch. CJicm. Gcs. xiv. 433.

2 Stanhoiise, Proc. Soy. Soc. xix. 41 ; Merz and Zeller, Bcr. Deutsch, Chem.
(jrcs. xii, 2038.

8 Beckmann's History of Inventions, vol. \. p. 37.


As several documents, still preserved among the Florentine
archives, confirm the above account of the origin of this family
name, from the discovery of dyeing with oricello, 1 we may, in

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