Full text of "The British coal-tar industry : its origin, development, and decline"

THE BRITISH
COAL-TAR INDUSTRY

ITS ORIGIN, DEVELOPMENT,
AND DECLINE

EDITED BY

WALTER M. GARDNER, M.Sc., F.I.C.

PRINCIPAL OF THE BRADFORD TECHNICAL COLLEGE ; EDITOR OF THE
"JOURNAL OF THE SOCIETY OF DYERS AND COLOURISTS"

WITH ILLUSTRATIONS

PHILADELPHIA

J. B. LIPPINCOTT COMPANY
LONDON : WILLIAMS & NORGATE

CONTENTS

INTRODUCTION .... vii

I. 1868. THE ANILINE OR COAL-TAR COLOURS. By W. H.

PERKIN, F.R.S. (Cantor Lectures) . . i

II. 1870. THE ARTIFICIAL PRODUCTION OF ALIZARINE. By

Professor H. E. ROSCOE, F.R.S. . 46

III. 1879. THE HISTORY OF ALIZARIN AND ALLIED COLOURING

MATTERS. By W. H. PERKIN, F.R.S. ... 54

IV. 1880. THE NEWER ARTIFICIAL COLOURING MATTERS

DERIVED FROM BENZENE. By R. J. FRISWELL,

F.C.S., F.I.C. ... . 60
V. 1881. INDIGO AND ITS ARTIFICIAL PRODUCTION. By Pro-
fessor H. E. ROSCOE, LL.D., F.R.S. . . .71
VI. 1885. THE COLOURING MATTERS PRODUCED FROM COAL-
TAR. By W. H. PERKIN, F.R.S 75

VII. 1886. RECENT PROGRESS IN THE COAL-TAR INDUSTRY. By

Professor Sir H. E. ROSCOE, M.P., LL.D., F.R.S. 106
VIII. 1886. THE SCIENTIFIC DEVELOPMENT OF THE COAL-TAR
COLOUR INDUSTRY. By Professor R. MELDOLA,
F.C.S., F.I.C. . . .121

IX. 1896. THE ORIGIN OF THE COAL-TAR COLOUR INDUSTRY
AND THE CONTRIBUTION OF HOFMANN AND HIS
PUPILS. (Hofmann Memorial Lecture.) By W. H.
PERKIN, Ph.D., D.C.L., F.R.S. , . . 141

X. 1901. THE SYNTHESIS OF INDIGO. By Professor R.

MELDOLA, F.R.S., F.I.C. . . 188
XI. 1901. THE RELATIVE PROGRESS OF THE COAL-TAR IN-
DUSTRY IN ENGLAND AND GERMANY DURING THE
PAST FIFTEEN YEARS. By ARTHUR G. GREEN,
F.I.C., F.CS. . 189
XII. 1901. THE INDIGO CRISIS 204

XIII. 1902. APPLIED CHEMISTRY, ENGLISH AND FOREIGN. By

Sir J. DEWAR, M.A., LL.D., D.Sc., F.R.S. . .222

XIV. 1903. THE RELATION BETWEEN SCIENTIFIC RESEARCH AND

CHEMICAL INDUSTRY. By Professor R. MELDOLA,
F.R.S 227

349277

vi THE BRITISH COAL-TAR INDUSTRY

PAGE

XV. 1905. HISTORY OF THE COAL-TAR COLOUR INDUSTRY
BETWEEN 1870 AND 1885. By Professor R.
MELDOLA, F.R.S. ... . .228

XVI. 1906. NOTE ON THE PERKIN JUBILEE . . 232

XVII. 1908. PERKIN OBITUARY NOTICE. By Professor R.

MELDOLA, F.R.S. . ... 233

XVIII. 1908. THE FOUNDING OF THE COAL-TAR COLOUR INDUSTRY.

By Professor R. MELDOLA, F.R.S. . . 234

XIX. 1908. LETTER FROM PROFESSOR H. CARO TO PROFESSOR

R. MELDOLA, MAY 1908 . . . -257

XX. 1910. TINCTORIAL CHEMISTRY, ANCIENT AND MODERN.

By Professor R. MELDOLA, F.R.S. . . . 259

XXI. 1910. PATENT LAW IN RELATION TO THE DYEING INDUSTRY.

By A. G. BLOXAM, F.I.C. . . 269
XXII. 1910. THE COAL-TAR COLOUR INDUSTRY OF ENGLAND:
CAUSES OF ITS PROGRESS AND RETARDATION.
By I. SINGER 280

XXIII, 1914. THE ARTIFICIAL COLOUR INDUSTRY AND ITS POSI-

TION IN THIS COUNTRY. By F. M. PERKIN,
Ph.D., F.I.C. . . 298

XXIV. 1914. THE SUPPLY OF CHEMICALS TO BRITAIN AND HER

DEPENDENCIES. By Sir WILLIAM A. TILDEN,
D.Sc., LL.D., F.R.S. . . 315

XXV. 1914. BRITAIN AND GERMANY IN RELATION TO THE
CHEMICAL TRADE. By WILLIAM R. ORMANDY,
D.Sc., F.C.A. . 335

XXVI. 1914. THE MANUFACTURE OF ANILINE DYES IN ENGLAND.
By The Right Hon. Lord-Justice MOULTON, P.C.,
K.C., F.R.S. . .351

XXVII. 1915. GERMAN CHEMICAL INDUSTRY THIRTY YEARS AGO.

By The Right Hon. Sir H. ROSCOE, F.R.S. . 365

XXVIII. 1915. THE MANUFACTURE OF DYESTUFFS IN BRITAIN. By

Professor W. M. GARDNER, M.Sc., F.I.C. . . 371
XXIX. 1915. THE CHEMICAL INDUSTRIES OF GERMANY. By

Professor P. FRANKLAND, F.R.S. . . -379

XXX. 1915. PATENT LAW REFORM. By J. W. GORDON, K.C. . 389
XXXI. 1915. THE SUPPLY OF DYEWARES. By Professor R.

MELDOLA, D.Sc., LL.D., F.R.S. .... 401
XXXII. 1915. THE POSITION OF THE ORGANIC CHEMICAL IN-
DUSTRY. By Professor W. H. PERKIN, F.R.S. . 407

INDEX OF NAMES 429

INDEX OF COLOURING MATTERS 434

TABULAR AND STATISTICAL INFORMATION . ... 437

INTRODUCTION

As a side issue of the war the industry of the manufacture
of synthetic dyestuffs has been brought prominently before the
public during the past twelve months. And this has occurred
not because of its magnitude for the annual value of the
products used in Britain did not much exceed 2,000,000,
but because the products were essential to the carrying on of the
great textile industries of the country, and they were chiefly
imported from Germany.

It was quickly recognised that our virtual dependence upon
Germany for dyestuffs jeopardised our textile trade and many
others, such as the manufacture of paints, which involve the use
of pigments ; and the annual value of the industries concerned
cannot be less than 220,000,000. The stock of dyewares held
in this country is never equal to more than a few months* supply,
and the processes involved in their production are of such a
nature that the manufacture cannot quickly be improvised.
Realising therefore that the resources of private enterprise were
unequal to the task of making the necessary provision, the
Government appointed a commission of inquiry which eventually
resulted in the formation of a State-aided limited company
British Dyes Ltd. established to manufacture or otherwise
provide synthetic dyestuffs on a scale commensurate with the
national requirements.

The history of the origin and development of the coal-tar
colour industry is of great interest not only to the chemist and
the student of industrial economics, but also to the politician, the
leader of industry, and even to the general reader. To each of

vii

viii THE BRITISH COAL-TAR INDUSTRY

these it has a significant message. The industry which originated
and received its early development in this country has grown to
be one of great profit and importance, but after a period of much
prosperity here (1856 to about 1870) it became gradually more
and more centralised in Germany, and has latterly been one of
her most profitable industries ; the average dividend paid by the
six largest manufacturing firms being upwards of 20 per cent, on
a nominal capital of about 8,000,000, which represents only a
small fraction of the capital actually expended, most of which has
been written off out of profits.

The development in Germany of many other associated
industries has been the direct outcome of the success of their
dyestuffs industry ; for example, the production of synthetic
medicines, scents and flavourings, the manufacture of photo-
graphic drugs and of fine chemicals generally, the production of
artificial fertilisers and of high explosives, and the incidental
production of the necessary reagents such as sulphuric acid and
caustic soda on an enormous scale.

The ramifications of the influence of the coal-tar colour
industry in Germany are indeed most astonishing, and a close
investigation of the causes of their success will well repay those
who are responsible for the future success of British industry.

It is with the object of affording easily accessible material for
such an inquiry that this book has been compiled. It comprises
the chief lectures and addresses given in this country on the
subject since the establishment of the industry by Perkin in
1856 to the present day. The papers are given in chronological
order, and the book naturally divides itself into two portions, the
first twenty-two papers (pp. i to 297) dealing with the history
and development of the industry, and the latter portion (Papers
XXIII. to XXXIL, pp. 298 to 427) dealing with the problem as
it has presented itself since the outbreak of the war.

The reasons given for the relative decline of the British
industry and its phenomenal development in Germany are
numerous and varied. Amongst the former may be mentioned

INTRODUCTION ix

the supposed lack of well-trained chemists in this country, our
admitted early neglect of chemical research, defects in our patent
laws, the excise restrictions on alcohol, our fiscal system, want of
enterprise and of co-operation amongst the British manufacturers,
apathy of successive Governments towards industry (as distinct
from commerce), and the early neglect of science by the old uni-
versities which is not unconnected with a corresponding ignorance
and neglect on the part of our legislators and the general mass
of citizens.

These various topics are all dealt with in one or other of the
papers reprinted herein, and they have a direct bearing not only
on industries based on organic chemistry such as those men-
tioned in a previous paragraph, but have also a profound bear-
ing on the general question of the relation of science to industry.
And it cannot be too often or too strongly stated that the
future of British industry depends on a full utilisation of science
in our industries.

One point which is frequently lost sight of in discussing the
reasons for our virtual loss of the coal-tar colour industry is that
this industry has not been largely developed in any country other
than Germany. If countries differing so widely in fiscal, excise,
and patent laws, governmental and public appreciation of science,
industrial conditions, etc., as Britain, France, and the United
States, are equally unable to develop a particular industry which
flourishes in Germany, this appears to point to the existence of
some specially favourable set of conditions in Germany rather
than to the action of some deterrent condition in Britain.

The compiler of the book desires to express his great in-
debtedness to the authors of the various papers, and to the
editors of the journals in which they originally appeared, for their
kind permission to reproduce them herein.

WALTER M. GARDNER.
BRADFORD, September ist, 1915.

L: 1868
THE ANILINE OR COAL-TAR COLOURS

BY W. H. PERKIN, F.R.S.

(Cantor Lectures : Journal of the Society of Arts, 1868,
pp. 99, 109, 121)

COAL TAR, BENZOL, NITROBENZOL, ANILINE, AND
ANILINE PURPLE OR MAUVE

IN this short course of lectures it is my desire to bring before
you a somewhat condensed history of the artificial colouring
matters, generally known as the " coal-tar colours." By this
designation it is not meant to imply that colouring matters
actually exist in coal tar, and may, therefore, be extracted from it,
but that coal tar is the source of certain products which, when
changed by various chemical processes, are capable of yielding
coloured derivatives. You will thus perceive that it is important
for us to consider the various means employed to obtain the raw
materials before giving our attention to the colouring matters
themselves. We will, therefore, at once proceed to the considera-
tion of "coal tar," its formation and constitution.

Coal tar consists of the oily fluid formed by the destructive
distillation of coal, and is obtained as a secondary product in the
manufacture of coal gas. Originally, coal tar was a great
nuisance to the gas manufacturer, and it was often a problem to
him what he should do with it. I need scarcely say that this state
of things is now changed. In the gasworks the coal is distilled
in large retorts, sometimes twenty-five or thirty feet in length.
They are made of fireclay or iron, and several are arranged in one
furnace, or oven, as it is usually termed. Each retort is fitted with
an iron mouthpiece, from which a vertical tube rises, the mouth-
piece also having a door fastened with a cross-bar and screw.

2 THE BRITISH COAL-TAR INDUSTRY

When in use these retorts are rapidly filled with coal by
means of a proper scoop, and then the doors luted and fixed so
as to be airtight. Distillation commences immediately, as the
retorts are constantly kept red-hot. The gas and other products
which form pass up the front vertical pipe (connected with the
mouthpiece), through a bend, and down into a long horizontal
tube, called the " hydraulic main/' Here most of the oily pro-
ducts condense, and as they accumulate pass on with the gas down
the general main and flow into a tank provided for their reception.
These oily products constitute " coal tar." The coal gas, leaving
this tar behind, passes on to the condensers, and deposits a second
but smaller quantity of tar, and is then purified and stored in the
gas holders. The gas, however, does not interest us now.

I am here distilling some coal in a small glass retort, the beak
of which is inserted into one of the openings of a three-necked
receiver. The second opening is connected with a tube, so that
the gaseous products may be examined, whilst the third and lower
one is fitted to a small bottle, in which you see we have already
obtained a quantity of an oily fluid. This is our coal tar.

Having now seen how coal tar is produced, we will consider
of what it consists. Coal tar is by no means a definite body,
but contains a great number of different substances, as a glance
at the following table will show :

TABLE I. PRODUCTS OF THE DISTILLATION OF COAL.

Name.

Formula.

Boiling-point
Centigr.

Hydrogen ....

Marsh gas (hydride of methyl)

(CH 3 )H

...

Hydride of hexyl .

(C 6 H 13 )H

Hydride of octyl .

(C 8 H 17 )H

106

Hydride of decyl .

(CioH 21 )H

'S3

Olefiant gas (ethylene) .

C 2 H 4

Propylene (tritylene)

C 8 H 6

...

Caproylene (hexylene) .

C 6 H 12

(Enanthylene (heptylene)

C 7 H 14

Paraffin

cjau

Acetylene

C 2 H 2

...

Benzol

C 6 H 6

80-8

Parabenzol

C 6 H 6

97'5

Toluol .

C 7 H 8

Xylol .

C 8 H 10

139

THE ANILINE OR COAL-TAR COLOURS

TABLE I. continued.

Name.

Formula.

Boiling-point
Centigr.

Cumol ......

C 9 H 12

148-4

Cymol ......

C 10 H 14

1707

Naphthaline .....

C 10 H 8

212

Paranaphthaline (anthracene)

C 14 H 10

C TT

Pyren .......

^64

^15 4

...

Water

|H}

100

Hydrosulphuric acid ....

{H} S

...

Hydrosulphocyanic acid

|(CN)} S

Carbonic oxide .....

Carbonic anhydride ....

C0 2

. . .

Bisulphide of carbon ....

CS 2

Sulphurous anhydride ....

SO 2

- 10

Acetic acid

1 (C 2 H 8 0) }

I2O

Carbolic acid (phenol)

{(C 6 ^ 5 )}

188

Cresylic alcohol (cresol)

i<cSk)}

203

Phlorylic alcohol (phlorol) .

{ (C 8 H 9 ) }

...

Rosolic acid

...

Brunolic acid

...

f^i

Ammonia ....

- 33

(H)

( (C 6 H 5 ) }

Aniline ......

182

Pyridine ... .

(C 5 H 5 )'"N

II5

Picoline ... . .

(C 6 H r )'"N

T 34

Lutidine ... . .

(C 7 H 9 )'"N

Collidine ... .

(C 8 H n )'"N

170

Parvoline ... .
Coridine ... . .

(C 9 H 13 )'"N
(C 10 H 15 )'"N

1 88

211

Rubidine ... .

(C n H ir )'"N

230

Viridine ... .

(C 12 H 19 )'"N

25 1

Leucoline ... .

(C 9 H r )'"N

235

Lepidine ... .

(C 10 H 9 )"'N

260

Cryptidine ... .

(C n H n rN

256

Pyrrol .... .
Hydrocyanic acid

HC 5 N

133

26-5

4 THE BRITISH COAL-TAR INDUSTRY

This list, however, does not indicate all the constituents of coal tar,
but only those which chemists have up to the present time (1868)
succeeded in separating from it ; moreover, when we consider
how greatly coal differs in composition, and also that the products
vary according to the temperature to which the coal has been
submitted, it is evident that coal tar must be an almost endless
source of chemical products. Many would perhaps consider
this list a perfectly hopeless jumble of names impossible to
impress upon the memory ; but, fortunately, chemists are able to
classify their products, so that this formidable array of substances
may be grouped under three or four different heads only, and,
therefore, their relationship being once understood, little diffi-
culty is experienced in remembering their names.

Amongst these products, and at the lower part of this table,
you will observe a substance called " aniline." This substance
is of great interest to us, being one of the principal sources of
the coal-tar colours. Aniline was discovered by Unverdorben,
in 1826, amongst the products of the distillation of indigo, and
from its property of forming crystalline compounds with acids
was called " krystalline." Afterwards Runge obtained it from
the distillation of coal, and, because it gave a blue coloration
with a solution of chloride of lime, called it " kyanol " or blue
oil. Fritsche, still later, obtained aniline by the distillation of
indigo with hydrate of potassium, and gave it its present name,
derived from anil, the Portuguese for indigo. About this time
Zinin discovered a remarkable reaction, by which he obtained
aniline from a substance called nitrobenzol ; he called it, however,
" benzidam." The products obtained by these different chemists
were not at first known to be identical ; and it was not until Dr
Hofmann investigated the subject that they were all shown to be
the same body, aniline.

Zinin's process for the conversion of nitrobenzol into aniline
consisted in treating the nitrobenzol with an alcoholic solution
of sulphide of ammonium ; this was greatly improved upon by
Bechamp, who employed a mixture of finely divided iron and
acetic acid, in place of sulphide of ammonium.

This is a brief sketch of the history of aniline up to the time
of the discovery of the mauve dye ; it was then purely a
laboratory product, and was prepared in very small quantities
at the time, and only when required for scientific research.
Chemists have always been desirous of producing natural organic

THE ANILINE OR COAL-TAR COLOURS 5

bodies artificially, and have in many instances been successful.
It was while trying to solve one of these questions that I
discovered the " mauve." I was endeavouring to convert an
artificial base into the natural alkaloid quinine, but my experiment,
instead of yielding the colourless quinine, gave a reddish powder.
With a desire to understand this peculiar result, a different base
of more simple construction was selected, viz. aniline, and in
this case I obtained a perfectly black product ; this was purified
and dried, and when digested with spirits of wine gave the
mauve dye.

You will perceive that this discovery did not in any way origin-
ate from a desire to produce a colouring matter, as is sometimes
stated, but in experiments of a purely theoretical nature.

After showing this colouring matter to several friends, I was
advised to consider the possibility of manufacturing it upon the
large scale, and was, eventually, induced to make the experiment,
though, I must confess, not without considerable fear of the
result, especially as my chemical advisers set before me anything
but encouraging prospects. In starting this manufacture, the first
difficulty was to decide upon the source from which aniline could
be obtained at a sufficiently low price. It was at once evident
that indigo was by far too costly a product for this purpose.
Attention was therefore directed to the extraction of aniline from
coal tar, but after very numerous experiments it was found that
the difficulty of purifying it was so great, that it was not practi-
cable to prepare it at a reasonable price from this product. There
was, therefore, but one source left, namely, nitrobenzol ; but to
prepare aniline from this body necessitated the establishment of
a new manufacture, nitrobenzol at that time not being a com-
mercial article, and, although it could be produced in small
quantities without much difficulty, yet when tons were required
at a limited cost many obstacles presented themselves.

Having spoken of nitrobenzol, it will be necessary, before
proceeding further, to tell you something of the body it is
prepared from, and also how it is made in quantity. Nitrobenzol
is produced from a derivative of coal tar called benzol you will
see it mentioned in the list of coal-tar products. It is composed
exclusively of carbon and hydrogen, and is therefore called a
hydrocarbon.

Benzol was discovered by Faraday, in 1825, one year before
aniline by Unverdorben. Its existence in coal tar was first

6 THE BRITISH COAL-TAR INDUSTRY

pointed out by Dr Hofmann, in 1 845, and afterwards Mansfield
showed that an almost unlimited supply might be obtained from
this source. Benzol is a volatile oil, boiling at a temperature of
80- 8 C., nearly twenty degrees lower than water, and is also
very inflammable, burning with a smoky flame. When ignited
it cannot be extinguished by water, as it floats upon its surface.
Its vapour, when mixed with air, is explosive. It is also very
dense. This I can easily show you by decanting a small quantity
of benzol vapour several times from one vessel into another, and
then igniting it. Instances have been known, when distilling
benzol in large quantities, and some leak in the apparatus has
occurred, so that its vapour has escaped, that it has run along
the ground, and been ignited by a furnace situated thirty or
forty feet distant, and instantly run back to the apparatus. To
illustrate this I will pour some benzol vapour into the top of a
slightly inclined trough, fourteen feet long, at the lower end of
which is placed a lamp. The vapour will be seen to run gradually
down till it reaches the lamp, where it ignites, and the flame in-
stantly rushes back to the top of the trough. One of the most
remarkable properties of benzol is, that when cooled down to nearly
the freezing point of water, it solidifies to a beautiful crystalline
mass. This property of benzol is sometimes taken advantage of
when it is required in a very pure state, as the impurities which
accompany it are fluid, and do not freeze when cooled with ice.

Benzol is often sold under the name of " benzine collas," for
the purpose of removing grease from wearing apparel. But let us
consider how benzol is separated from the great number of pro-
ducts with which it is associated in coal tar. The first operation
consists in distilling the coal tar, just as it comes from the gas-
works, in large stills, holding one or two thousand gallons each ;
these are often made of old steam-boilers. At first very volatile
and light oily products come over, and are collected until their
density increases to such an extent that they no longer float upon
water. These constitute crude coal-tar naphtha. The distillation
is then carried on, and heavy, or, as they are technically termed,
" dead," oils are collected, a residue of common pitch being left
in the still. This pitch is generally run out, and cast into blocks ;
but sometimes the distillation is carried on after the dead oils
have been obtained, when a mixture of solid oily products distils,
nothing but a kind of coke being left behind. These latter
substances, however, do not interest us now.

THE ANILINE OR COAL-TAR COLOURS 7

The light oil, or crude coal-tar naphtha, is then purified by
one or two alternate distillations with steam and treatments with
concentrated sulphuric acid. It is thus rendered a colourless
fluid. Thus purified, coal-tar naphtha contains, besides benzol,
at least four or five other bodies. These, however, mostly differ
from benzol in being less volatile ; therefore, the naphtha is again
distilled, the first, or more volatile, portions only being collected
for benzol. By repeating this process of fractional distillation
several times, commercial benzol is obtained. Some manufacturers
employ stills of a peculiar construction, which enable them to
obtain a good product by a smaller number of distillations.

Benzol, when treated with fuming nitric acid or aquafortis,
undergoes a remarkable change. At first the two fluids mix and
become of a dark brown colour and slightly warm ; in the course
of a few moments red fumes appear, and the mixture enters into
ebullition. During this violent action the colour of the liquid
becomes lighter and ultimately changes to orange. If water be
now added to this product, the benzol, which is such a light
body, will be seen to have completely changed into a dense
yellow oil sinking in water. This oil is nitrobenzol. Nitro-
benzol was discovered in 1834, by Mitscherlich. It solidifies
into a crystalline mass at a temperature of about 3 C. ; its
odour is like that of the oil of bitter almonds, and before the
introduction of coal-tar colours it was made in small quantities,
and sold under the name of Essence de Myrbane, for the purpose
of scenting soap.

From the energy with which benzol is attacked by fuming
nitric acid, nitrobenzol at first appeared to be a most difficult
product to manufacture on the large scale, and this difficulty
seemed the greater when it was found necessary that it should
be made at a moderate cost. Moreover, at the time I am now
referring to, fuming nitric acid, sp. gr. 1-5, could not be obtained
in the market, or only at such a cost as almost to preclude its use.
Under these circumstances, two mixtures were experimented
with instead of the nitric acid in a very concentrated condition.
The first was a mixture of nitrate of sodium and sulphuric acid,
the second a mixture of ordinary nitric acid, sp. gr. 1-3, and
sulphuric acid. The mixture of sulphuric acid and nitrate of
sodium was preferred, and employed on the large scale.

The first apparatus used in the manufacture of nitrobenzol,
for the preparation of aniline for the mauve dye, is shown in

8 THE BRITISH COAL-TAR INDUSTRY

fig. i. It consisted of a large cast-iron cylinder, a, fitted with a
stirrer, b, and closed with a door, c, fastened by a cross-bar and
screw, d. This cylinder was capable of holding between thirty
and forty gallons. It was provided with two necks, e e : one for
the introduction of the benzol and sulphuric acid, which were
supplied through a syphon tube ; the other for the exit of
nitrous fumes. This last was connected with an earthenware
worm, to condense any benzol which might be volatilised by the
heat of the reaction. The nitrate of sodium was always intro-
duced into the cylinder before the door was fastened up and
luted. Until the preparation of nitrobenzol was understood,
there was a great amount of uncertainty in its manufacture, and

FIG. i.

several explosions occurred, but fortunately without causing any
injury to the workmen attending the apparatus. These explosions
originated generally from the liberation of too much nitric acid
from the nitrate of sodium, by the sulphuric acid, before the
formation of nitrobenzol had begun, so that, when it started, the.
chemical action set in with such energy that an explosion ensued.
After a few of these unpleasant occurrences, however, sufficient
experience was obtained to get the manufacture under control.
Apparatus of a much more extensive character has since been
substituted for the cylinders.

The process of preparing nitrobenzol with a mixture of
sulphuric acid and nitrate of sodium in place of nitric acid may
be carried on very well in this apparatus, provided sufficient
sulphuric acid be employed to produce an acid sulphate of
sodium, as this will be found quite fluid at the close of the

THE ANILINE OR COAL-TAR COLOURS 9

operation, and can be freely run out at the small outlet. A
mixture of strong nitric acid and sulphuric acid is now usually
employed for the conversion of benzol into nitrobenzol. In
working by this latter method the entire charge of benzol is first
introduced through a large opening in the lid ; this is then
closed and the stirrer set moving ; the nitric and sulphuric acids
are then cautiously run in through small pipes, care being
taken not to add too much nitric acid, until the red fumes begin
to appear. After all the charge of acids has been added, and the
reaction has perfectly ceased, the product is drawn off. At first
a mixture of sulphuric and nitric acids runs out, and then the
nitrobenzol ; this is collected separately and purified, first by
agitation with water, and then rendered perfectly neutral by
means of a dilute solution of soda. Should it contain any un-
converted benzol this may be distilled off by means of steam.
On the Continent manufacturers do not appear to have succeeded
well in manufacturing nitrobenzol when it first became a com-
mercial article ; their difficulty appears to have arisen from the fact
that they experimented in earthenware vessels, which are both
dangerous and unsuitable, and it was not until information was
obtained from England, I believe, that they were able to produce
this body at a moderate price.

We will now pass on to the processes for converting nitro-
benzol into aniline. I have already mentioned that Zinin was
the first who discovered that nitrobenzol could be converted into
aniline, or, as he termed it, benzidam. His process consisted in
treating an alcoholic solution of nitrobenzol with ammonia and
sulphuretted hydrogen ; but, although the discovery of this pro-
cess was one of great importance from many points of view, still
it was very tedious. Bechamp, however, found that by employing
a mixture of acetic acid and finely divided iron instead of ammonia
and sulphuretted hydrogen, the nitrobenzol was very rapidly
converted into aniline, and this process has been found the best
yet proposed (1868) for manufacturing aniline in large quantities.
Many other reagents have been suggested, such as arsenite of
sodium, powdered zinc, etc., but none of them have been found
so advantageous as iron and acetic acid.

In carrying out Bechamp's process, cylinders like those used
for nitrobenzol (fig. i) were originally employed. The cylinder
was set in brickwork and heated by means of a small furnace,
iron borings were first introduced, and the door fixed in its place,

io THE BRITISH COAL-TAR INDUSTRY

airtight. One neck was connected to the upper extremity of a
cast-iron worm by means of a pipe called an adapter ; the second
neck being fitted with a syphon-tube, for the introduction of the
nitrobenzol and acetic acid. In working on the large scale it is
necessary to add the nitrobenzol and acetic acid in small quantities
at a time, otherwise the reaction is so violent as to almost burst
the apparatus : by working carefully, however, there is no need
to fear any difficulties, especially if the stirrer is well used. By
the time all the charge has been introduced, a quantity of fluid
will have distilled over ; this is returned into the cylinder and
the fire lit, and the aniline distilled off.

The principal change which has taken place in this process
consists in using high-pressure or superheated steam for the
distillation instead of fire, and working the apparatus by means
of a steam-engine instead of by hand.

Aniline thus obtained is generally redistilled with addition of
a little lime or caustic soda, for the purpose of decomposing
a body called acetanilide, which is often produced in the manu-
facture of aniline, especially if the operation is conducted over a
fire instead of with steam.

Commercial aniline generally appears of a pale sherry colour ;
when chemically pure it is colourless, but if kept long it becomes
quite brown. It possesses a peculiar odour, which is slightly
vinous when the aniline is pure. It burns with a smoky flame,
but is not very inflammable : its boiling-point is 182 C. One
of its most characteristic reactions is its power of producing a
blue or blue-violet coloration with chloride of lime, to which I
shall again have occasion to refer. Aniline differs entirely from
benzol and nitrobenzol, being perfectly soluble in dilute acids.
This is owing to its being an organic base, and forming compounds
with acids. Thus with hydrochloric acid it forms hydrochlorate
of aniline ; with sulphuric acid, sulphate of aniline, etc.

We will now, in a very rapid and general way, glance at the
chemical changes which take place in converting benzol into
nitrobenzol and aniline.

Benzol, as I have already stated, is a hydrocarbon, i.e. a body
composed of hydrogen and carbon only ; it is represented by

C 6 H 6 .

This is treated with nitric acid, which contains the elements

HN0 3 .

THE ANILINE OR COAL-TAR COLOURS n

The nitric acid acts upon the benzol and introduces its nitrogen
and part of its oxygen, at the same time removing hydrogen and
forming water.

HN0 3 + C 6 H 6 = C 6 H 5 N0 2 + H 2 O.

Nitric acid. Benzol. Nitrobenzol. Water.

Nitrobenzol, when treated with iron and acetic acid, is converted
into aniline by the influence of hydrogen gas, in what is termed
the nascent state, or the peculiar condition in which it is when
in the act of being liberated from a compound.

This hydrogen unites with the oxygen of nitrobenzol and
removes it as water, and at the same time two atoms of hydrogen
combine with the deoxygenated nitrobenzol, forming aniline.

C 6 H 5 N0 2 + H 6 = C 6 H 7 N + 2 H 2 O.

Nitrobenzol. Aniline.

Having now seen the various operations which require to be
performed for the production of aniline from coal tar, we are
prepared for the consideration of its coloured derivatives. We
will, therefore, commence at once with the first of the coal-tar
colours, the " mauve " dye. I have already given you the history
of its discovery ; I will now tell you how it is made.

First of all, aniline and sulphuric acid, in the proper propor-
tions for the formation of sulphate of aniline, are mixed in
a large vat with water, and boiled until perfectly dissolved.
Bichromate of potassium is then dissolved in a second large vat.
These two solutions, when cold, are mixed in a third and still
larger vessel, and allowed to stand one or two days. In this way
a large quantity of a fine black precipitate is formed ; this is
collected upon shallow filters, well washed with water, and then
dried. When dry it is a most unpromising sooty-black powder,
and contains various products besides the mauve ; the most
troublesome of these is a brown, resinous product, soluble in
most of the solvents of the colouring matter itself.

At first this resinous substance was removed by digestion
with coal-tar naphtha previously to the extraction of the colouring
matter, which was afterwards effected with methylated spirits
of wine, and the solution thus obtained when distilled left the
mauve as a fusible bronze-coloured mass.

When digesting the black precipitate with naphtha or strong
spirits of wine, the operation had to be performed in closed
vessels under pressure or in connection with a condensing

12 THE BRITISH COAL-TAR INDUSTRY

arrangement, otherwise large quantities of these valuable solvents
would have been lost ; and great difficulty was experienced in
getting apparatus perfectly tight, on account of the " searching "
character of these fluids. Substitutes had also to be found for
the ordinary materials employed by engineers for making good
manhole joints, and a number of other matters which are appar-
ently of but small importance, but it is remarkable the amount
of difficulty and annoyance they caused. The method of ex-
traction has, however, been materially improved upon by substi-
tuting dilute methylated spirits of wine for strong, as this weaker
spirit dissolves only a small quantity of resinous matter but all
the colouring matter, so that the digestion with coal-tar naphtha
is now found unnecessary.

The solution of the colouring matter in dilute spirit is placed
in a still and the spirit distilled off, the colouring matter remaining
behind in aqueous solution ; this is filtered and then precipitated
with caustic soda. It is afterwards collected on a filter, washed
with water, and drained until of a thick pasty consistence, and,
if necessary, dried.

The solid mauve dissolves very freely in spirits of wine,
forming an intensely coloured solution ; it is also soluble to a
small extent in water, but the aqueous solution on cooling forms
a kind of jelly.

The formation of the mauve or aniline purple by the action
of bichromate of potassium upon sulphate of aniline is a process
of oxidation, and since the publication of the original specification
at the Patent Office a great number of patents have been taken
out for the preparation of this colouring .matter, in which the
bichromate has been replaced by other oxidising agents, as per-
oxide of lead, permanganate of potassium, peroxide of manganese,
chloride of lime, ferricyanide of potassium, chloride of copper,
etc. ; but I need not make any special remarks upon these various
processes, as experience has shown that bichromate of potassium
and a salt of aniline, the reagents first proposed, possess ad-
vantages over all others, and are now nearly universally employed
for the preparation of aniline purple. The next best process
appears to be that of Dale and Caro, in which chloride of copper
is employed.

The affinity of aniline purple for silk or wool is very re-
markable, and if I take some wool and pass it through a solution
of mauve, you will see how rapidly it absorbs it, even from a

THE ANILINE OR COAL-TAR COLOURS 13

very dilute solution. Aniline purple is sent into the market in
three different conditions, in paste, in solution, and in crystals ;
but the latter are very rarely employed, as they are very expensive
and do not offer corresponding advantages to the consumer.

The mauve is the most permanent coal-tar purple known,
especially with respect to its power of resisting the action of
light.

I will now endeavour to give you some idea of the approxi-
mate amount of the various products we have considered obtain-
able from 100 Ibs. of coal, and for this purpose I have arranged
them in the following table with their respective weights :

Ibs. ozs.

Coal . . 100 o

Coal tar

Coal-tar naphtha
Benzol .
Nitrobenzol .
Aniline .
Mauve .

10 12

o 8

O 2-
O O;-

You see the smallness of the amount of colouring matter
obtainable from coal or coal tar ; but there is fortunately one
thing which, to some extent, compensates for this, and that is
the wonderful intensity of this colouring matter. 1 will illustrate
this remarkable fact. I have here a large carboy containing nine
gallons of water, and will now add to this a solution containing
one grain of mauve, and illuminate the liquid with the magnesium
lamp, and you see the single grain has coloured this large bulk
of water. A gallon of water contains 70,000 grains, therefore
nine gallons contain 630,000 grains. This solution, then, contains
only one part of mauve to 630,000 of water.

MAUVE, MAGENTA, AND SOME OF THEIR DERIVATIVES

Aniline purple is sometimes supplied to consumers in a pure
and beautifully crystalline condition. This product is found to
be a salt of a compound, chemically termed an organic base.
This base has been called " mauveine " ; it is composed ex-
clusively of carbon, hydrogen, and nitrogen, in the following
proportions :

C 27 H 24 N 4 .

i 4 THE BRITISH COAL-TAR INDUSTRY

Mauveine, although the base of aniline purple, when in solution
is not of a purple but of a dull violet shade, and in the solid
state is a nearly black crystalline powder. The moment, however,
mauveine is brought in contact with an acid so as to form a salt,
its solution changes to a purple colour. This takes place even
with that feeble acid, carbonic acid. I have here a dilute solution
of mauveine ; you will observe the dull violet colour it possesses,
but if my assistant only breathes through it a few moments the
carbonic acid of his breath will combine with it, and it will
acquire the ordinary colour of aniline purple.

Mauveine is a most powerful chemical body, and will easily
decompose ammoniacal salts. This may be readily seen if some
mauveine be heated with chloride of ammonium and a little
water, when an abundance of ammonia gas will be evolved, which
can be distinguished not only by its odour, but by the white
fumes it produces with hydrochloric acid.

The salts of mauveine are beautifully crystalline, and possess
a splendid green metallic lustre. The crystallised commercial
product consists of the acetate. Mauveine possesses one of the
peculiar properties of indigo. Indigo, when treated with re-
ducing agents, such as a mixture of sulphate of iron and lime,
is rendered nearly colourless and soluble, but this colourless
indigo, when subjected to the oxidising influence of the atmo-
sphere, rapidly becomes blue again. I here refer to the indigo
vat so much used by dyers. Mauveine, when treated in a
similar manner, is also nearly decolourised, changing to a pale
brownish-yellow fluid, but the moment this is exposed to the
air it assumes its original colour far more quickly than indigo.
This remarkable fact may be strikingly illustrated by boiling
an alcoholic solution of salt of mauveine with a few strips of
zinc, in a sealed tube from which the air has been previously
removed. The dark purple solution will gradually lose its
colour, and change to a very pale yellowish-brown shade.

I have a tube containing some aniline purple decolourised in
this manner, and now if I open it, the air rushes in and the
solution instantly assumes the ordinary purple colour.

Ordinary indigo is quite insoluble in water, and, therefore, its
property of becoming soluble, as well as colourless, when treated
with reducing agents, is of great practical value, as the dyer, by
immersing his goods in this solution of indigo, and then exposing
them to the oxidising influence of the air, gets the colouring

THE ANILINE OR COAL-TAR COLOURS 15

matter firmly fixed in the fibre of his materials. But as the
mauve is already soluble in water, this property has not been
found of any practical value.

Aniline purple, when introduced as a dye, being the first
colour of its kind, had to encounter many prejudices, and, on
account of its peculiar nature, required the adoption of new or
modified processes for its application. These difficulties, however,
once overcome, its progress was very rapid. At first it was
principally employed by the silk dyer and printer, its application
to silk being comparatively easy, but it was not used by the
calico-printer till a few years afterwards.

I distinctly remember, the first time I induced a calico-printer
to made trials of this colour, that the only report I obtained
was that it was too dear, and it was not until nearly two years
afterwards, when French printers put aniline purple into their
patterns, that it began to interest British printers.

It will be seen that to introduce a new coal-tar colour after the
mauve was a comparatively simple matter. The difficulty in the
manufacture of all the raw materials had been overcome, as well
as the obstacles in the way of the practical applications of an
aniline colour to the arts.

We will now turn our attention to a colouring matter which
has often been confounded with aniline purple. I have
designated it as " Runge's blue," as it was first observed by
Runge. I have mentioned that Runge, when he first obtained
aniline, termed it " kyanol," or blue oil, on account of the blue-
coloured solution it gave with chloride of lime.

After discovering the mauve, I naturally made experiments
with this coloured product of Runge's, to see if it contained
aniline purple, but my experiments answered the inquiry in the
negative. A few years afterwards, however, I was puzzled by
finding that French manufacturers were beginning to produce
aniline purple by the agency of chloride of lime and a salt of
aniline ; being much occupied at that time, I was unable to look
carefully into the matter, and it was not until investigating these
apparently opposite results a short time since that I was able to
understand them. I will perform Runge's experiments, and for
that purpose will take a solution of hydrochlorate of aniline, and
add to it a very dilute solution of chloride of lime (taking care
not to add too much). The solution is now changing, and
getting slightly opaque ; by daylight it has an appearance like

1 6 THE BRITISH COAL-TAR INDUSTRY

indigo, but if I render it clear by the addition of alcohol, and
place it before the magnesium lamp, it is seen to be of a brilliant
colour, and nearly pure blue, quite unlike aniline purple.

I have lately succeeded in obtaining this blue product in the
solid condition, by treating a solution of hydrochlorate of aniline
with a dilute solution of chloride of lime, and precipitating the
resulting colouring matter with common salt ; it is thus obtained
in an impure condition, and may be collected upon a filter ; by
treatment with cold ether or benzol, a large quantity of brown
impurities are separated, the colouring matter being left in the
solid condition. This substance dissolves in alcohol, forming a
nearly pure blue solution, and is capable of dyeing silk a blue or
blue-violet colour.

An alcoholic solution of Runge's blue behaves with caustic
potash quite differently from aniline purple, forming a brownish-
red-coloured solution instead of a violet. Therefore, there can
no longer be any reason for confounding this body with aniline
purple, it being entirely different, both in colour and chemical
properties. But as this colouring matter is produced by oxidising
hydrochlorate of aniline with chloride of lime, how is it that
manufacturers have succeeded in preparing aniline purple from
the same reagents ? This question I find is very easy to answer :
the manufacturer has gone a step further and boiled his product.
Now, if I take a piece of silk dyed with Runge's blue, and
instead of boiling it, which would wet it and make it difficult to
manipulate, do that which is equivalent steam it a very
remarkable change takes place, Runge's blue being changed into
the mauve. So, here we have cleared up the mystery, and find
that by the action of chloride of lime on hydrochlorate of aniline
we first get Runge's blue, and then by heating this blue we
change it into mauve. Runge's blue is a very unstable body,
and of no practical value, its alcoholic solution changing into
mauve in a day or two. This change takes place directly on
boiling.

We must now pass on to another colouring matter, in name
well known to all of you I mean magenta, also called roseine,
fuchsine, aniline red, and various other names. The discovery
of this body and its manufacture were strangely dependent upon
the source which had been selected for the preparation of aniline
for the mauve. Had the aniline contained in coal tar, or the
aniline obtained from indigo, been employed for the preparation

THE ANILINE OR COAL-TAR COLOURS 17

of the mauve, instead of that prepared from commercial benzol,
magenta and its train of coloured derivatives would in all
probability have remained unknown to this present day, from the
simple fact that magenta cannot be produced from pure aniline,
a second body being also required.

You will observe, by reference to the table of coal-tar products,
that next to benzol there is a substance named toluol, a substance
having a boiling-point not very much above that of benzol. On
this account toluol is always contained in commercial benzol, and
it possesses most of its properties. With nitric acid it forms
nitrotoluol, very similar to nitrobenzol ; with iron and acetic
acid it is converted into a base, toluidine, very similar to aniline,
except that it is solid instead of liquid when pure. Therefore,
aniline prepared from commercial benzol always contains a little
toluidine, and this is the second body requisite for the formation
of magenta.

An apparatus for the fractional distillation of coal-tar naphtha
has been devised, so that its constituents may be almost com-
pletely separated from each other, and thus pure benzol or pure
toluol may be obtained. 1 Having obtained these hydrocarbons,
pure aniline and pure toluidine may be prepared and then mixed
in the most suitable proportions for manufacturing magenta.
This process is not very generally employed, however, but the
quality of the mixture of aniline and toluidine is determined by
distillation, noting the quantities which come over at different
temperatures. The necessity of toluidine as well as aniline for
the production of magenta was discovered by Dr Hofmann, who
found that it could not be produced by perfectly pure aniline,
nor perfectly pure toluidine, but that a mixture of these two
bases yielded it in quantity. Magenta was apparently first
observed by Natanson in 1856, when examining the action of
chloride of ethylene on aniline, and afterwards by Dr Hofmann
in 1858, when studying the action of tetrachloride of carbon
on aniline ; but industrially the discovery of magenta was made
by M. Verguin, of Lyons, in 1859, three years after the mauve.
M. Verguin's process consisted in treating commercial aniline with
a fuming liquid, called tetrachloride of tin, and was first carried
out by Messrs Renard Brothers, of Lyons. Since 1859 patents
have been taken out for the production of this colouring matter
with aniline, and almost all chemicals known, whether capable

1 See Clarke's Eng. Pat., 5th June 1863, No. 1405.

1 8 THE BRITISH COAL-TAR INDUSTRY

or incapable of forming magenta. I may mention one process
which was extensively employed, and is still used to some extent
in Germany, and that is the method of making magenta with
commercial aniline and nitrate of mercury. With care this
process works very well, and the colouring matter produced is
of good quality. When first introduced, magenta prepared by
this method was not purified, but sent into the market in a crude
form, so that before using it the dyer had to extract it with water.
In the preparation of magenta by this process, all the mercury
of the nitrate of mercury employed is recovered in the metallic
state ; but although this process may possess some advantages,
yet the use of mercury salts is most undesirable, on account of
their fearfully deleterious influence upon the workmen.

The process which has almost superseded all others involves
the use of arsenic acid, as proposed by Medlock, and patented
by him in January 1860. This patent is notorious for the
amount of litigation it has caused, showing that a patentee should
not only be a discoverer but a lawyer, and even more, and able
to discover precisely how much to claim and disclaim in his
patent, and also to arrange his specification so that the intellects
of the whole world may not be able to discover a single flaw in
his description ; and it is a misfortune common to inventors who
wish to thoroughly protect themselves, to find that they have
claimed too much.

The manufacture of magenta, as now carried on, is a very
simple process ; it is conducted in an apparatus somewhat
similar to that represented by fig. 2.

This apparatus consists of a large iron pot, a, about 4 ft.
diameter, set in a furnace of brickwork ; it is provided with a
stirrer, b y worked by hand. All the gearing for this stirrer is
fixed to the lid, so that stirrer, lid, and all may be lifted away
by means of a crane, or other suitable apparatus. There is also
a bent tube fixed into the lid, and connected to a condensing
worm, d y by means of a joint, which can be made or broken at
pleasure. In preparing magenta, a quantity of aniline, containing
about 25 per cent, of toluidine, and a nearly saturated solution
of arsenic acid, are introduced into this apparatus, and well mixed
by working the stirrer ; the proportions of the materials are in
about the ratio of i of aniline to 1-5 of a 75 per cent, solution
of arsenic acid. When these are well mixed the fire is lighted.
After the product has been heated for some time, water begins

THE ANILINE OR COAL-TAR COLOURS 19

to distil over, then aniline and water, and lastly nearly pure
aniline.

This operation requires some hours for completion, and this
is determined by inserting an iron rod, from time to time, and
drawing out a portion of the product for examination, as well as
by the amount of aniline which distils over. When the heating
has been completed, a steam pipe is introduced into the apparatus
and steam blown through the fused mass ; by this means an
additional quantity of aniline is separated. The lid is then
liberated and lifted, with the stirrer, from the apparatus, and
the product left to cool before it is removed. A more elaborate

FIG. 2.

and larger apparatus is sometimes used, which possesses con-
siderable advantages over the smaller one. The iron pot is
larger, and is provided with an outlet at the side, which is closed
during the operation, and the shaft of the stirrer is hollow
(as in the aniline apparatus described previously), and worked
by steam. When the operation of heating is concluded, steam
is blown down the shaft, and after the addition of water the
product is boiled and run out of the outlet in the side of the
pot ; by this arrangement it is unnecessary to disconnect the
lid of the apparatus, and the product does not require to be
removed by mechanical means, as with the apparatus described
above.

The crude product obtained by heating aniline and arsenic
acid is next transferred to vats, boiled with water, and filtered.

20 THE BRITISH COAL-TAR INDUSTRY

Common salt is then added, which precipitates the crude
magenta ; this is collected and dissolved in boiling water, again
filtered, and the solution, on cooling, deposits the colouring
matter in the crystalline condition. This, when recrystallised,
constitutes commercial magenta.

Commercial magenta consists of brilliant crystals, sometimes
half an inch in length, having a beautiful golden-green metallic
appearance ; these dissolve in warm water almost entirely, forming
an intense purplish-red solution. Dr Hofmann has carefully
studied the chemical nature of magenta, and has found it to
consist of the salt of an organic base, which he has called
rosaniline. This base may be obtained from the commercial
product, by dissolving it in water and boiling it with an alkali,
or alkaline earth, such as ammonia, potash, or lime ; it is thus
rendered nearly colourless, and after filtration rosaniline separates
from the clear solution, on cooling, in colourless crystals. It
is composed of carbon, hydrogen, and nitrogen when anhydrous,
but generally contains an equivalent of water also. The
anhydrous base has the formula

This colourless base immediately becomes dark red upon
combining with an acid, as I can show you by heating some with
acetic acid, when the colour is immediately developed. The
magenta produced by heating commercial aniline with nitrate
of mercury is the nitrate of rosaniline ; that produced with
arsenic acid is the arseniate, but in the process of purification
this latter salt becomes converted into hydrochlorate, which is
the salt most generally found in the market. Other salts are
also commercially manufactured, such as the oxalate and the
acetate, especially when a very pure product is required ; these
salts are generally prepared from pure rosaniline, by combining
it with the required acid, and crystallising from water.

The acetate of rosaniline crystallises in magnificent octahedra,
possessing the ordinary golden-green metallic lustre to a very
high degree ; it is also the most soluble salt of rosaniline known.
The affinity of magenta for animal fibres is very great ; it does
not, however, resist the action of light nearly to the same extent
as the mauve. All the derivatives of rosaniline also possess a
very great affinity for animal fibres, in most cases quite equal to
that of magenta itself.

THE ANILINE OR COAL-TAR COLOURS 21

When speaking of aniline purple, I showed you that by
reducing agents it became colourless, or nearly so, but that the
original colour was developed when it was exposed to the oxygen
of the air. Salts of rosaniline or magenta are also decolourised
by reducing agents, but, unlike aniline purple, the colour is not
restored by exposure to the air. Dr Hofmann has found that
in this case a new organic base is produced which he has called
leucaniline. This substance differs only from rosaniline in con-
taining an additional quantity of hydrogen. It may be recon-
verted into rosaniline by oxidising agents such as bichromate
of potassium, etc.

There is another very peculiar reaction of rosaniline. This
base when brought in contact with hydrocyanic acid, instead of
forming a coloured hydrocyanate of rosaniline, yields a perfectly
colourless body, which is not a salt but a base. This remarkable
fact was discovered by Dr Hugo Milller, and he has called this
new body hydrocyanrosaniline. We shall have occasion to refer
again to this substance and leucaniline.

In the formation of magenta, a second product is obtained,
commercially called phosphine. This substance was first intro-
duced by Mr E. Nicholson. Dr Hofmann has investigated it,
and found it also to contain an organic base, which he has
called chrysaniline.

Phosphine or chrysaniline is not capable of being produced at
will, and the quantity formed in the manufacture of magenta is
variable. In shade it is of rather a yellow orange. This
colouring matter differs from rosaniline, the base of magenta,
in exactly the opposite direction to leucaniline, containing two
atoms less of hydrogen. Leucaniline, rosaniline, and chrysaniline
are thus related :

Leucaniline C 20 H 21 N 3

Rosaniline C 20 H 19 N 8

Chrysaniline ...... C 20 H 17 N 3

The principal use of phosphine is for the formation of a
scarlet with magenta. It is not converted into magenta, nor
decolourised with reducing agents or hydrocyanic acid, and
therefore does not seem to be of the same class of colouring

... &

matters as rosaniline.

From the residues obtained in the manufacture of magenta
three new colours have been obtained by Messrs Girard and
De Laire, but, I am sorry to say, my time will not allow me to

22 THE BRITISH COAL-TAR INDUSTRY

enter into the particulars of these products. I believe they have
not been commercially introduced as yet.

Magenta is now more used as a source of other colours than
as a dye. This has caused its manufacture to be conducted on
a very extensive scale, and it is now looked upon by the
manufacturer as a raw material much in the same way as aniline
was regarded in the early days of aniline purple.

We will next consider some of the derivatives of magenta,
and the first we will study is aniline blue or bleu de Lyon. If
aniline be treated with a salt of rosaniline or magenta, a remark-
able change takes place : at first the colour gradually becomes
purple, but afterwards gets quite blue, ammonia being evolved
at the same time. This peculiar reaction was observed by MM.
Girard and De Laire, who found that this change of colour was
due to the formation of a new body, which they termed the bleu
de Lyon ; intermediate products were likewise obtained, to which
we shall refer presently. MM. Girard and De Laire patented their
process in January 1 8 6 1 . This new aniline blue is one of the most
important of the artificial colouring matters, and its manufacture
has been very much improved upon since its discovery. There
are several circumstances which materially influence the beauty
of its tint, such as the quality of the aniline and the particular
salt of rosaniline employed in its manufacture. It is found by
experience that the aniline should be as pure and free from
toluidine as possible, and that the salt of rosaniline should
contain a feeble acid, such as the acetate, valerate, oleate, or
benzoate ; but why the latter is necessary chemists are unable to
understand at present. Practically, the various salts of rosaniline
required for the manufacture of the blue are not prepared
separately, but are produced in the operation by double decom-
position, which is simply a process of exchange ; thus, if acetate
of rosaniline is required, a mixture of hydrochlorate of rosaniline
and acetate of sodium is employed ; these react on each other,
and change into acetate of rosaniline and chloride of sodium.

Aniline blue is manufactured in enamelled iron pots heated
by an oil bath. A mixture of magenta, acetate of sodium, and
aniline is introduced into the pots, the aniline being employed
in excess. When charged the oil bath is heated up to 190 C.,
and kept near that temperature. At first the red colour of the
mixture changes slowly, but afterwards with rapidity. The
progress of the operation is ascertained by removing the wooden

THE ANILINE OR COAL-TAR COLOURS 23

plug, and withdrawing a small quantity of the product upon the
end of an iron or glass rod, and it is considered complete when
a good blue colour has been obtained ; to ascertain this point
with precision, considerable experience is necessary. The excess
of aniline distils during this operation, and is condensed by the
worm, and collected in a suitable receiver, so that it may be
used again.

From the crude blue product thus obtained, which is a fluid
of the consistency of treacle, all the different qualities of blues
found in the market are prepared. The cheaper qualities are
obtained by simply treating the crude product several times with
hydrochloric acid. This removes all the free aniline, and most
of the red and purple impurities. Another similar but more
effective process is employed for the preparation of the better
qualities, and consists in mixing the crude product with methy-
lated spirits of wine, and pouring it into water acidulated with
hydrochloric acid, and then thoroughly washing with water the
colouring matter which it precipitates. But for the purest kinds
of blue there are several processes employed ; these are based
upon the difficult solubility of some of its compounds in alcohol.
In preparing these very pure qualities of blue, instead of starting
with the crude product, one of the purified blues is taken.

Aniline blue, or "bleu de Lyon," is supplied to consumers
as a coarse powder having a coppery lustre, or in alcoholic
solutions ; it is nearly insoluble in water, and has to be dissolved
in alcohol before it is added to the dye bath.

The nature of this blue has been determined by Dr Hofmann.
It is found to contain, like magenta, a colourless base, becoming
blue only upon combining with acids. Dr Hofmann has shown
this base to contain

^88"tl^'t

and has called it " triphenylrosaniline." Like rosaniline, it
becomes colourless when treated with nascent hydrogen, forming
a new base, giving colourless salts, as leucaniline. The com-
position is

CsgH^Ng.

The insolubility of aniline blue in water has been found a
great drawback to its use, because when employed for dyeing it
is thrown out of solution in the dye bath, and then mechanically
adheres to the goods, so that it afterwards rubs off.

24 THE BRITISH COAL-TAR INDUSTRY

Mr Nicholson has, however, discovered a process for rendering
this blue perfectly soluble in water. His process closely corre-
sponds to that employed to render indigo permanently soluble.
This, it will be remembered, is effected by subjecting indigo to
the action of concentrated sulphuric acid, whereby a sulpho acid
is produced.

Mr Nicholson has found that aniline blue, when treated by a
similar process, also forms a sulpho acid, perfectly soluble in
water, and forming with alkalies nearly colourless solutions.
These, however, when decomposed by acids, change back to the
original blue.

This soluble blue is now much used for silk- dyeing, but by
dyers it is not thought to be so fast as the normal compound.
By some modification of the process just described, Mr
Nicholson has obtained another soluble blue, commercially
known as " Nicholson's blue." This is now very extensively
employed in Great Britain for wool-dyeing, but its application
does not appear to be well understood in France and Germany,
so that its use there is not so great as in our own country.

If a salt of rosaniline and aniline be heated together, and the
process stopped before aniline blue is produced, the resulting
product when treated with dilute acid gives a colouring matter,
which has been called "violet imperial." This was at first
supposed to consist of a mixture of blue and magenta, but
recent research has shown it to consist of intermediate products.
Very large quantities of this colouring matter have been used,
but its consumption is now rapidly falling off, owing to the
introduction of the new violets, about to be described. A few
months after the discovery of aniline blue, another colouring
matter, called the " bleu de Paris," was obtained by MM.
Persoz, de Luynes, and Salvetat. These chemists found that
when aniline was heated with tetrachloride of tin for thirty hours
to 1 80 C. in a sealed tube, neither a red nor a violet, but a very
pure blue, was produced. This colouring matter is generally
described as being identical, or probably identical, with the " bleu
de Lyon." These blues are, however, widely different in their
chemical nature, as the " bleu de Paris " is easily soluble in water,
and crystallises freely in needles of a blue colour, with a coppery
reflection. It consists of the hydrochlorate of an organic base,
which is precipitated from its solution by alkalies as a purplish-
blue powder ; it dyes silk readily, and retains its blue colour by

THE ANILINE OR COAL-TAR COLOURS 25

artificial light. It is remarkable that the discoverers of the " bleu
de Paris " do not seem to have observed its difference from the
bleu de Lyon."

I have prepared some of this product with a view to its
examination, but hitherto have been prevented from determining
its composition. I hope to do so soon.

The " bleu de Paris " is, unfortunately, difficult to prepare in
large quantities, and has never been introduced commercially.

The recognition of the nature of the " bleu de Lyon," by Dr
Hofmann, led him to study the action of a class of substances
upon rosaniline, known to chemists as the iodides of the organic
radicals ; this investigation resulted in the discovery of the
brilliant colours known as the Hofmann violets, and of which so
many shades can be obtained, from a very red purple to a nearly
pure blue.

The substances generally used for the preparation of the
Hofmann violets from rosaniline are the iodides of methyl and
ethyl : the iodide of methyl differs from that of ethyl in a
practical point of view, in being rather quicker in its action ; it
is also more volatile. Both these substances contain a remarkable
element called iodine. This body is found in sea-water and sea-
weed ; its aspect is very similar to that of a metal ; one of its
characteristic properties is that when heated it volatilises and
produces a beautiful purple-coloured vapour, and here we find
how dangerous a little knowledge is when relied upon. When
the iodide of ethyl, which, as I have told you, contains iodine,
was introduced for the preparation of the Hofmann violets, it
was stated in some of our periodicals or daily papers, I do not
remember which, that chemists had at last succeeded in fixing
the colour of iodine, whereas the iodine has nothing whatever
to do with the colours produced with the iodides of ethyl and
methyl, but is simply an instrument in bringing about the change
which takes place in their formation ; moreover, these colours
can be equally produced without using iodine at all. It is
unfortunate that the popular reports upon scientific matters are
generally so utterly untrustworthy. One of the most remarkable
reactions of iodine is the blue-violet colour it gives with a solution
of starch ; this is used as a test for its presence when in the free
condition, and is remarkably delicate ; it is of no use as a colour,
as it is instantly decomposed when heated. To prepare iodide of
ethyl, ordinary alcohol is treated with iodine and phosphorus ;

26 THE BRITISH COAL-TAR INDUSTRY

, the operation has to be conducted with care, as iodine reacts
upon phosphorus with great energy ; usually the alcohol and
phosphorus are placed in a retort, and the iodine added very
carefully, and in small quantities at the time. The mixture is
then distilled, and the distillate mixed with water, which causes
the iodide of ethyl to separate as a colourless heavy oil. Iodide
of ethyl is very volatile, boiling at 70 C. ; it has an ethereal
odour, and when pure is colourless and transparent ; it contains
no less than 81 per cent, of iodine. Iodide of methyl is
prepared in exactly the same manner as that of ethyl, substituting
wood naphtha, or methylic alcohol, for ordinary alcohol ; it
contains a still larger quantity of iodine than the iodide of ethyl,
viz. 89 per cent.

For the preparation of these substances on the large scale
special apparatus has been devised, and sometimes amorphous or
red phosphorus is substituted for the ordinary kind ; but I shall
not have time to enter more fully into this subject. To produce
the violets, Dr Hofmann heats pure rosaniline with iodide of
ethyl, or methyl and methylated spirits of wine, in a cast-iron
digester, closed airtight, with a lid fastened down with screws.
A process very similar to this is sometimes employed, and
consists in using a salt of rosaniline, caustic alkali, iodide of
ethyl, and alcohol. But in Germany the ordinary hydrochlorate
of rosaniline is employed with alcohol, or wood spirit and iodide
of ethyl, and is found to work very successfully. By employing
the rosaniline itself a lower temperature is required for the
formation of violet than when using its salts ; in fact, I have
found that a mixture of iodide of ethyl and rosaniline reacts
even at the ordinary temperature if left in contact for a few days,
and produces a red shade of violet.

On the large scale Hofmann's violet is generally prepared
in deep cast-iron vessels, surrounded by a steam jacket, and
provided with a lid having a perforation, closed with a screw
plug. This lid can be firmly fastened down with screws, the
joint being made with a vulcanised indiarubber washer. This
apparatus is charged with a mixture of hydrochlorate of rosaniline
dissolved in alcohol or wood spirit, and iodide of ethyl or methyl,
in proportion according to the shade required. After the
apparatus is closed the steam is allowed to enter the steam jacket,
and the heating continued for five or six hours ; the plug is then
removed from the lid of the apparatus, and the alcohol or unused

THE ANILINE OR COAL-TAR COLOURS 27

iodide of ethyl distilled off. The resulting product is dissolved
in water, filtered, and precipitated with chloride of sodium, but
sometimes it is first treated with caustic alkali, to remove all the
iodine, so that it may be recovered. Thus obtained, the colour-
ing matter is of a golden lustre if of a blue shade, and of a
greenish lustre if of a red shade.

Like all the other colours we have considered, the Hofmann
violets are nearly white organic bases, their composition differing
according to the shade of colour, thus :

A red shade is composed of . . . C 22 H 2S N 3
A red-violet shade, of .... C 24 H 27 N 3
A very blue shade C 26 H 31 N 8

The colours of the Hofmann violets are remarkable for their
brilliancy, but, unfortunately, they do not resist the action of
light so well as* might be desired ; it is remarkable, however,
that the regard for fastness seems to have given way to the
desire for brilliancy.

In the early days of coal-tar colours fastness was so much
talked about, that when magenta was first introduced it was
thought by some that it would not be largely used how
different has it proved to be ! Although not very fast upon
cotton, the Hofmann violets are sufficiently so for woollen and
silk goods, as colours always resist the light better when applied
to animal fibres.

In the formation of Hofmann violets we see that rosaniline,
when treated with iodide of ethyl, becomes blue, the red being
converted into violet ; but with mauveine, the base of the mauve,
exactly the reverse takes place, the mauveine being converted
into a much redder shade with iodide of ethyl. The colouring
matter produced from mauveine and iodide of ethyl is com-
mercially known as " dahlia " ; the colour is intermediate in shade
between aniline purple and magenta. The colouring matter
possesses the same character for fastness as the mauve, and also
gives the same reactions with acids ; unfortunately, it is rather
expensive, and has therefore not been very extensively used.

Lastly, there has been a process proposed for the production
of colouring matters similar to the Hofmann violets, by first
converting the aniline into ethyl-aniline, a base previously dis-
covered by Dr Hofmann. It is found that by substituting this
base for aniline, in some of the processes which have been em-

28 THE BRITISH COAL-TAR INDUSTRY

ployed for the manufacture of magenta, the ethyl-aniline yields
purple or violet colouring matters.

This process has been patented by MM. Poirrier and Chappat,
but the reaction appears to have been first observed by M. E.
Kopp. From the great similarity of these colouring matters
to the Hofmann violets, I need not enter into any lengthened
description of their properties.

Sea-water contains, besides iodine, another remarkable
element called bromine ; it is a liquid giving off very irritating
orange-coloured vapours. This remarkable body yields, with
many hydrocarbons, a great variety of compounds. With
ordinary turpentine, it acts with great violence ; but if the action
be moderated by the presence of a large quantity of water, a
thick viscid oil is obtained. This body was examined by Mr
C. Greville Williams, who found it to possess the formula

I have found that this substance, when heated with a solution
of magenta in methylated spirits, produces a purple colouring
matter of great beauty, commonly known as Britannia violet ;
it is very extensively employed for dyeing and printing, and can
be produced of any shade, from purple to a blue violet.

The Britannia violet possesses the golden-green lustre so
common to all the aniline colours. It is easily fusible, amorph-
ous, and very soluble in water.

Earlier in my lecture I showed you the great intensity of the
mauve dye. I will now make a few experiments, to illustrate
the great intensity of some of the colouring matters we have
been considering this evening.

I have here some screens of white paper, on which I have
dusted a very small quantity of the solid colouring matters
so small a quantity that I daresay you can scarcely discover its
presence. If I now project spirits of wine upon these screens,
so as to dissolve the colours, you will see their remarkable
intensity.

Let us now consider for a moment the great rapidity with
which the discovery of new coal-tar colours followed that of the
mauve or aniline purple.

Aniline purple was discovered in 1856 ; three years after-
wards, in 1859, the magenta was introduced. In 1861 we had
the aniline blue; in 1863 the Hofmann violet; and in 1865

THE ANILINE OR COAL-TAR COLOURS 29

the Britannia violet. Thus we see that all these colours have
not only been discovered, but introduced commercially, in a
period of less than ten years.

We have now reviewed the principal coal-tar colours, but
there still remain some important ones for our consideration ;
and although some of these are not at present largely used,
yet it is to them, perhaps, that we may look for the future
development of this branch of industry.

Ill

VARIOUS ANILINE, PHENOL, AND NAPHTHALINE COLOURS
APPLICATION OF THE COAL-TAR COLOURS TO THE ARTS

The first green colouring matter to consider is the " aldehyd

freen," which owes its name to a substance called "aldehyd"
eing employed in its preparation. I must, therefore, first tell
you what aldehyd is.

Aldehyd is a product of the oxidation of alcohol ; it is a
volatile liquid possessing a very peculiar odour, and was dis-
covered by a chemist named Dobereiner, but analysed by Liebig.
It is obtained by treating alcohol with a mixture of bichromate
of potassium and sulphuric .acid, and was generally prepared in
glass retorts, but, now that it is required for colour making, the
glass apparatus is replaced by copper or leaden vessels.

Towards the end of 1861, M. Lauth described a reaction by
which rosaniline could be made to produce a blue colouring
matter ; but this product was found to be useless as a dye, on
account of its instability. It was produced by the action of
aldehyd upon a solution of rosaniline and sulphuric acid. This
useless colour was afterwards experimented upon by a dyer
named Cherpin, who, after a number of fruitless attempts at
fixing it, told his difficulties to a photographic friend, who evi-
dently thought if it was possible to fix a photograph it was possible
to fix anything else. He, therefore, advised his confidant to try
hyposulphite of sodium. On making i-this experiment, however,
the dyer did not succeed in fixing his blue, but found it converted
into a splendid green dye, now known as aldehyd green.

To prepare this colouring matter, a cold solution of magenta,
consisting of one part of colouring matter dissolved in a mixture
of three parts of sulphuric acid and one part of water, is em-

30 THE BRITISH COAL-TAR INDUSTRY

ployed ; about one and a half parts of aldehyd are added by
degrees to this solution, and when the whole is mixed it is heated
on a water bath, until a drop of the product diffused in water
produces a fine blue coloration. It is then poured into a
large quantity of boiling water, containing three or four times as
much hyposulphite of sodium as the magenta employed. After
boiling a short time the product is filtered off from a greyish
insoluble residue which forms. The filtrate contains the green.
This process being a very simple one, a great number of dyers
now prepare the colouring matter as they require it. It may,
however, be precipitated by means of tannin or acetate of sodium,
collected on filters and drained to a paste, and, if necessary, dried.
In both these forms it is found in the market.

The aldehyd green is principally employed in silk dyeing. It
is a splendid colour, and very brilliant both by day and artificial
light. The chemistry of this green is at present hidden in
obscurity, as it is very difficult to obtain in a chemically pure
condition. But, like the colouring matter previously described,
it is undoubtedly the salt of an organic base apparently containing
sulphur.

This base is colourless, or nearly so, and becomes changed
to the normal colour of aldehyd green upon the absorption of
carbonic acid.

It will also decompose ammonia salts, combining with the
acid and becoming green. I have here a solution containing the
colourless base of this green, an ammonia salt and a little free
ammonia. If I pour it upon a piece of white blotting-paper it
does not stain it, but if I heat it the ammonia salt is decomposed,
and we get the green developed with its ordinary intensity.

There is another green of an entirely different nature to
the aldehyd green ; it is called iodine green. This colouring
matter is always produced, but in variable quantities, in the
preparation of the Hofmann violets, from magenta and iodide of
ethyl or methyl. Of late much attention has been directed to
this colouring matter, and, by making a few alterations in the
process for preparing Hofmann violet, from forty to fifty per
cent, of product can now be obtained from the magenta used.
The iodine green is much used for cotton and silk dyeing ; its
colour is bluer than that of aldehyd green, and it is, therefore,
more useful, as it yields, with the addition of yellow, a greater
variety of green shades.

THE ANILINE OR COAL-TAR COLOURS 31

Iodine green contains an organic base which is not precipitated
by alkaline carbonates. With picric acid it forms a difficultly
soluble picrate, and is generally prepared on the Continent as a
paste consisting of this colour precipitated with picric acid and
drained on a filter. In England it is, however, sold in alcoholic
solution. It is a good green by gaslight.

The next green I have to bring before you is a magenta deri-
vative, commercially called " Perkin's green." In its properties
it resembles more closely the iodine than the aldehyd green, but
differs from this in its solubility, and in being precipitated by
solutions of alkaline carbonates, such as carbonate of sodium. It
is an organic base which is nearly colourless, and is by no means
a chemically powerful body. Like the iodine green, it is precipi-
tated by picric acid, forming a picrate which crystallises from
alcohol in small prisms with a golden reflection. This colouring
matter is principally employed for calico printing, and is now
extensively used. Thus you see we have three aniline greens,
some useful for one, and some for another purpose, so that the
silk and cotton dyer and the calico-printer, as well as others, can
be supplied. For fastness these greens are, I think, quite as
good as the violets ; the aldehyd green, however, I believe,
resists light the best.

In the formation of the mauve, or aniline purple, there is
always a small quantity of a second colouring matter produced,
of a rich crimson colour, similar to that of safflower. Several
years ago I examined this substance, and found it to dye silk
a remarkably clear colour, but owing to the press of other
matters, and the very small quantities in which it could be
obtained, 1 did not give it any further attention. By a new
process, however, it can now be produced in somewhat larger
quantities, and endeavours are being made to introduce it to the
arts, as it produces beautiful tints of pink upon silk and cotton,
and, moreover, can be used for printing cotton, silk, and wool
processes, to which safflower cannot be applied as it will not
bear steaming. This aniline pink or crimson is a beautiful
chemical body, crystallising in small prisms possessing a golden-
green lustre. It is soluble in alcohol, and also in water ; it
produces solutions remarkable for their fluorescence so much
so, that by certain lights they appear as if filled with a precipitate.
In colour and fastness it is equal to safflower, and, should it be
found possible to manufacture it at a moderate price, I should

32 THE BRITISH COAL-TAR INDUSTRY

imagine it would entirely supersede that colouring matter,
especially as it is not affected by alkaline solutions.

There is a product in the English market, supposed to be an
aniline colour, called " Field's orange," after its discoverer, Mr
Frederick Field. Its properties are those of a nitro-acid, but, as
its preparation has not been described, of course I cannot tell
you anything about it. With alkalies it forms a rich orange-
coloured solution, but by the addition of an acid it is precipitated
as a pale yellow powder.

Field's orange is a very useful colouring matter, having a
great affinity for animal fibres, and is extensively used for wool-
dyeing, as it resists the action of light very well.

We now come to a colouring matter of a very indefinite
nature. I refer to aniline black. This substance appears to be
closely allied to the insoluble part of the black precipitate formed
in the manufacture of the mauve. This precipitate, however,
always contains oxide of chromium, which cannot exist in the
aniline black generally employed, as no chromium compound is
used in its preparation ; but as copper compounds are used, it
may be that aniline black represents the black precipitate with
the oxide of chromium replaced by the oxide of copper, or it
may even be that in either case the metallic oxide is not an
essential part of this black substance.

Aniline black is perfectly insoluble, and has, therefore, to be
formed upon the fibre when employed for calico-printing. As
we shall have to refer to its application to dyeing and printing, I
will not make any further remarks upon it just now.

From mauve and magenta, chocolate, maroons and browns are
prepared ; but as they are of secondary importance as yet, I will
only just mention one or two of the methods of preparing them.

One of the processes for preparing chocolate from magenta is
by the action of nitrous acid, but care has to be taken to watch
the progress of the operation, and to stop it when the required
shade has been obtained. Another process consists in heating
magenta with hydrochlorate of aniline to a temperature a little
above 200 C. The product, when purified, produces a maroon
colour. Browns are generally obtained from a residue of
magenta making.

All the colouring matters we have considered up to the
present time are derivatives of aniline and toluidine, and con-
stitute nearly all the colours of the rainbow.

THE ANILINE OR COAL-TAR COLOURS 33

By the action of nascent hydrogen upon dinitrobenzol, Mr
A. H. Church and myself obtained, in 1857, a crimson colouring
matter, which was named nitrosophenyline. I have lately made
a few new experiments upon this remarkable body, and find that
it has an affinity for pure cotton, dyeing it of a clear cerise colour,
considerably less blue in tint than safflower. With very dilute
acids, this colouring matter forms a blue solution ; with less
dilute acid, a crimson colour ; and with concentrated sulphuric
acid, a green colour. It is difficult to judge of the probable
utility of this colouring matter, as it is so difficult to obtain in
quantity by the present process. I may mention that my new
experiments with this substance have caused me to doubt the
purity of the product examined by Mr Church and myself ; and
this is not remarkable when we consider how few methods of
purifying artificial colouring matters were known at the date of
our experiments, as well as the small amount of substances at
our disposal.

We now turn to a product very different from aniline, though
related to it in some respects very closely. On the table you
will see a coal-tar product called " phenol " or " carbolic acid."
It was discovered, a long time since, by Runge, and afterwards
studied by a great number of chemists. It is only, however,
during the last few years that it has been introduced into com-
merce in a pure condition, thanks to Dr Crace Calvert.

Phenol or carbolic acid is a splendid crystalline body, pos-
sessing many most interesting properties ; but I must confine
myself to a short account of its coloured derivatives only.

Carbolic acid, when treated with nitric acid, yields a yellow
acid, known as picric acid. The substance can be produced from
many other bodies besides carbolic acid, and when first employed
for dyeing purposes was generally prepared from the resin of
the Xanthorrhea hastilis, but now, owing to the cheapness and
purity of carbolic acid, I believe it is exclusively used in its
manufacture. Picric acid requires care in its preparation, if
phenol and strong nitric acid be employed, as the action is very
violent. Pure picric acid is of a very pale yellow colour ; it is
employed principally for silk-dyeing, the colour it produces on
silk being much darker than that of the acid itself. Picric acid
has a very bitter taste, and by some it is said to be a great
improvement upon hops in the manufacture of bitter beer,
especially as it has been proposed as a tonic in place of quinine.

34 THE BRITISH COAL-TAR INDUSTRY

Picric acid forms beautiful yellow salts, the most interesting
being that of potassium. This salt is extremely insoluble in
water, and very explosive ; it has been proposed as a substitute
for gunpowder for charging shells. Picric acid, under the
influence of cyanide of potassium, is perfectly decomposed, and
changed into a new compound called isopurpuric acid, a substance
isomeric with murexide. The potassium salt of this compound
is very explosive, and, to avoid danger, it is generally supplied
in a moist condition, and mixed with glycerine. It produces a
kind of maroon colour upon wool, but I do not think it has
been extensively used up to the present.

Runge, when experimenting with the products of the dis-
tillation of coal, obtained two compounds, called by him rosolic
and brunolic acids, which he regarded as products existing in
coal tar ; I think it most probable, however, that these bodies
were produced in his process of purification, and did not exist
ready formed in coal tar.

Rosolic acid was afterwards examined by Dr Hugo Mailer,
who obtained it from crude carbolate of calcium, which had
been exposed to the oxidising action of the air. This process,
however, does not yield rosolic acid in quantity ; but in 1861,
Kolbe and Schmitt described a method of producing this sub-
stance, by heating a mixture of oxalic, carbolic, and sulphuric
acids. It is stated, however, that this process was discovered
by M. Jules Persoz, in 1859. ^ ls by this method that rosolic
acid is now manufactured.

Commercial rosolic acid, commonly called aurine, is a
beautiful brittle resinous substance, having a slight green metallic
lustre ; when pure it may be crystallised, and if pulverised forms
a scarlet orange powder. Its solutions are of an orange colour,
but change with alkalies to a most magnificent crimson. It
has not been found capable of very many applications in dyeing
and printing, although it produces very good orange shades,
and with magenta it makes a very good scarlet.

The great difficulty in applying rosolic acid to the arts is
owing to the easy solubility of its salts in water. It appears to
be closely allied to rosaniline, as it has lately been found possible
to obtain it from this colouring matter.

When heated with ammonia, in a closed vessel, to 120 to
140 C., rosolic acid permanently changes into a new colouring
matter of a crimson shade, called peonine or coralline. This

THE ANILINE OR COAL-TAR COLOURS 35

forms beautiful tints upon silk, similar to safflower, provided
it is kept slightly alkaline, but if treated with the least quantity
of acid the freshness of its colour is destroyed. When heated
with aniline this colouring matter undergoes a similar change
to magenta, being converted into a blue called azuline. This
colouring matter, as well as coralline, was discovered by M. Jules
Persoz, and patented by MM. Guinon Mamas & Bonnet in 1862.
Azuline, when in the solid state, presents a coppery-coloured sur-
face ; it is soluble in alcohol, but difficultly so in water. It is not
manufactured now, having been replaced by the more brilliant
blues obtained from rosaniline, and described previously.

We must now turn our attention to another series of coal-
tar colours, derived from a beautiful product called naphthaline.
You will see it on the table of coal-tar products ; it is a hydro-
carbon containing

CioH 8

and may be obtained in any quantity. It is remarkable for the
readiness with which it sublimes, and, like benzol and toluol,
it yields with nitric acid a nitro-compound called cc nitronaphtha-
line," a beautifully crystalline body, and this, with iron and acetic
acid, yields an organic base called " naphthylamine." This base
is solid, and beautifully crystalline, but possesses a very dis-
agreeable odour.

Mr Church and myself obtained from a salt of " naphthyl-
amine " and a mixture of nitrate of potassium and potash, a
beautiful substance crystallising in orange needles with a green
lustre. It is called by a rather long name, " azodinaphthyldiamine."

This substance is a feeble organic base, and dissolves in
alcohol, forming an orange-coloured solution, which changes
to a splendid violet colour upon the addition of hydrochloric
acid. It has, however, been found useless as a dye, because
the purple colour only exists in the presence of free acid, and
the orange colour of the base itself is liable to turn brown when
exposed to the light. It would appear probable, however, that
azodinaphthyldiamine may become useful as the starting-point for
new colouring matters, as I have lately succeeded in producing
from it a very promising crimson substance, possessing a con-
siderable affinity for animal fibres.

A very beautiful yellow colouring matter has been obtained
by Dr Martius from naphthylamine, somewhat similar to picric
acid, but of a much more intense colour. It is prepared by

36 THE BRITISH COAL-TAR INDUSTRY

treating hydrochlorate of naphthylamine with nitrite of potassium ;
by this means a substance known as diazonaphthol is obtained ;
this is then heated with nitric acid, and is transformed into the
new yellow, chemically known as dinitronaphthol. This sub-
stance is commercially called Manchester yellow. It possesses
the properties of an acid. The commercial compound consists
of a beautifully crystalline calcium salt, soluble in water, and
dyeing silk or wool a magnificent golden-yellow colour.

Owing to an increasing demand for benzoic acid, experiments
have lately been made with a view of obtaining it from naphthal-
ine instead of gum benzoin, etc. For this purpose experiments
were made with an acid derived from naphthaline, called phthalic
acid, which, when carefully heated with lime, is found capable of
yielding benzoate of calcium, from which benzoic acid can be
prepared. But as in these processes secondary compounds are
formed, which interest us this evening, I will briefly describe the
process employed for obtaining these various substances.

First of all, naphthaline is heated with a mixture of chlorate
of potassium and hydrochloric acid ; in this way a mixture of
chloronaphthaline and bichloronaphthaline is obtained. These
products are then heated with nitric acid, and yield a mixture of
phthalic acid and a substance called the chloride of chloroxy-
naphthyl. The phthalic acid is converted into the calcium salt,
and heated with slaked lime to a temperature of 350 or 370 C.,
to convert it into a benzoate.

It is, however, the chloride of chloroxynaphthyl which
interests us now. This substance, when heated with an alkali,
yields the salts of an acid called chloroxynaphthalic acid, which
may be obtained in a free state by means of hydrochloric acid.
When pure, chloroxynaphthalic acid is a pale yellow crystalline
powder, forming beautiful compounds with baryta, zinc, and
copper. It dyes wool a scarlet colour. The great interest of
this substance consists in its supposed relationship to alizarine,
the colouring matter of madder, the only difference in composition
of chloroxynaphthalic acid and alizarine being in the former
containing an equivalent of chlorine in place of hydrogen, thus :

C 10 H 6 O 3 . . . Alizarine.

C 10 (H 5 C1)O 8 . . . Chloroxynaphthalic acid.

Many endeavours have been made to remove this chlorine,
and to put hydrogen in its place, with the hopes of producing

THE ANILINE OR COAL-TAR COLOURS 37

alizarine ; but, up to the present time, no definite results have
been obtained.

I am inclined to think that, although this relationship
of composition exists between these bodies, yet that their
chemical nature is quite dissimilar. We generally find that
chlorinated bodies have similar properties to those from which
they are derived or represent. Chloroxynaphthalic acid,
however, does not appear to possess properties similar to
alizarine. This acid dyes wool readily without a mordant ;
alizarine only slightly stains it. When boiled with cloth prepared
with alumina, or iron mordants, it scarcely produces any change,
while alizarine yields intense colours.

This process of preparing benzoic and chloroxynaphthalic
acids is carried out on a large scale in France, by MM. P. &
E. Depouilly, to whom I am indebted for the specimens of these
products shown in this lecture. Some of the chloroxynaphthalates
are beautifully coloured salts, and are used as pigments.

Laurent in his researches obtained a body from naphthaline
called carminaphtha. This product is now claiming the attention
of manufacturers, and is said to produce very fine shades of
colour upon fabrics.

Before making any further remarks upon the coal-tar colours,
I wish to draw your attention to some of their applications to
the arts.

I have told you that most of the coal-tar colours contain
carbon, hydrogen, and nitrogen, and that they are generally
organic bases. They differ essentially from most of the vegetable
colouring matters, which contain, with but few exceptions, only
carbon, hydrogen, and oxygen, and are weak acids. You will
thus understand that many difficulties had to be encountered in
their application for dyeing and printing, because they would not
combine with the ordinary mordants used for the colouring
matters of woods, such as alumina and oxide of tin. These
observations refer to the dyeing and printing of vegetable fibres,
and not to silk or wool, as these materials absorb the coal-tar
colours without the intervention of a mordant.

In silk-dyeing, the principal difficulty experienced in applying
the coal-tar colours was due to their great affinity for the fibre,
thus preventing the dyer from obtaining an even colour, especially
when dyeing light shades. After a time, however, it was found
that this obstacle could be overcome by dyeing the silk in a weak

38 THE BRITISH COAL-TAR INDUSTRY

soap lather, to which the colour had been added. This not only
caused the dyeing to proceed with less rapidity, but also kept the
surface of the silk in good condition. Silk dyed by this process
is left soft, but may afterwards be rendered hard or " scroop " by
rinsing in a bath of slightly acidulated water.

This process was first used for dyeing silk with the mauve
or aniline purple. It has, however, been since found suitable for
nearly all the aniline colours, such as magenta, Hofmann and
Britannia violets, etc. For dyeing silk with coal-tar colours of
an acid nature, such as picric acid, dinitronaphthol, etc., the silk
is simply worked in a cold aqueous solution of the colouring
matter, sometimes slightly acidulated, as when using the sulpho
acids of aniline blue or soluble blue. The process of printing
silk with aniline colours is comparatively simple. An aqueous
or alcoholic solution of the colouring matter is thickened with
gum Senegal, printed on with blocks, and, when dry, exposed to
the action of steam for about half an hour. The gum is then
washed off, and the goods finished.

Earlier in my lecture I referred to the formation of two
colourless products from magenta, the one called leucaniline,
and the other hydrocyanrosaniline.

Some few years since, it was found that if silk dyed with
magenta has the reagents necessary for the formation of these
colourless products printed upon it, what is called a discharge
style can be produced. One of the substances used for effecting
this change is powdered zinc mixed with gum. This process
also applies to all the coloured derivatives of magenta, and yields
better results than can be obtained by printing on the colouring
matter and leaving the white parts, because the colours are
always clearer when dyed than when printed. But this is not all.
When printing two colours on silk, say a pattern with a green
ground and purple spots, two blocks have to be used, the one
for the ground and the other for the spots ; and, when re-
moving the first block, the silk often moves slightly, therefore
when the spots are put in by the second block they do not
exactly register, and thus an imperfect result is obtained.
This difficulty, however, can be avoided by taking silk dyed
with any of the derivatives of magenta, and printing it with
the discharge previously mixed with the colour it is desired
to introduce, of course employing a colouring matter which is
not affected by the discharge, such as aniline purple, aniline

THE ANILINE OR COAL-TAR COLOURS 39

pink, etc. This discharge style has only been employed for silk
at present.

We will now turn our attention to the methods of dyeing
wool. These methods, as a rule, are very simple, the wool being
merely worked in a hot aqueous solution of the desired colouring
matter, no mordant being required. Acids are generally found
to be injurious, a neutral bath being preferred, and the operation
finished by bringing the temperature nearly up to that of boiling
water.

With the blue known as Nicholson's blue, the process of
dyeing is different from that just given, and consists of two
distinct operations, the wool being first worked in an alkaline
solution of the colour, which gives it a kind of grey or slate
shade, and then in an acid bath, which develops the colour.

The printing of wool is similar to that of silk, the colouring
matter being simply thickened with gum, printed on the goods,
steamed, and then washed.

The dyeing of cotton with aniline purple at first presented
many difficulties. This colouring matter was found to be capable
of producing a very beautiful colour without a mordant, and it
was proposed to employ it in this manner, but the colour thus
obtained would not bear washing, being nearly all removed with
hot water and soap. Mordants, such as alum, were then ex-
perimented with, but these gave no results. After some time
Mr R. Pullar and myself found a method of applying this
colouring matter to cotton, which is based upon the insolubility
of the compounds it forms with tannin. In using this process
the cotton is first soaked in a decoction of sumac or some
other tannin agent, then in a solution of stannate of soda, and,
lastly, in water slightly acidulated with sulphuric acid. The
cotton thus prepared contains an insoluble compound of tin and
tannin, which possesses a great affinity for aniline purple. The
stannate of soda may be replaced by alum, or a solution of tin
salt. This method of preparing cotton has been found suitable
for nearly all the aniline colours discovered since the mauve, and
is now almost universally employed in Great Britain for cotton-
dyeing. Other processes have been proposed for cotton-dyeing,
but are not so generally employed as the one just described.

We now pass on to the application of coal-tar colours to the
art of calico-printing. The mauve, when first introduced, was
applied to printing in a very simple manner ; the colouring

40 THE BRITISH COAL-TAR INDUSTRY

matter was merely mixed with gum and albumen, printed on the
goods and steamed ; by this process the albumen became in-
soluble, and fixed the colour. Caseine and gluten were some-
times used as substitutes for albumen. Being dissatisfied with
this mechanical mode of applying aniline purple, in conjunction
with Mr Grey I made a number of experiments with a view of
obtaining some more chemical method of fixing this colouring
matter, and at last succeeded. The process proposed consisted
in printing the pattern with a salt of lead, then converting this
into the oxide or a basic salt, by passing the goods through an
alkaline solution. Thus prepared, they were worked in a boiling
solution of aniline purple in soap. In this way a very pure
colour was obtained on the mordanted parts, the soap keeping
the whites pure. This process, however, was of very limited
application, as it could only be applied for single-colour patterns.
After this, several processes were patented for the use of tannin
for fixing the mauve ; these were based upon the method of
dyeing cotton previously mentioned, and some very fast results
were obtained ; but as these methods are now out of use, I will
not describe them further.

The process now nearly universally employed in the north
was discovered by M. Alexander Schultz and myself ; it consists
in printing the colouring matter with a mordant composed of
a solution of arsenite of alumina in acetate of alumina. On
steaming the cloth printed with this mixture for about half an
hour, the colour is firmly fixed in the fibre. After steaming,
the goods are generally soaped, and then finished. One of the
great advantages of this process is that it can be worked in
patterns with a great variety of colours, and is also suitable for
nearly all the aniline colours, as well as the mauve, yielding
shades of great brilliancy.

During the last few years, much attention has been given
to the application of aniline black in calico-printing. This
substance is not prepared in the separate condition, but formed
on the fabric ; it is produced by printing a mixture of a salt of
aniline, chlorate of potassium, and sulphide of copper, thickened
with starch, upon the goods, and in this manner a dull grey
impression is obtained ; but, after three or four days' ageing,
this changes to a dark olive, and is then rendered perfectly black
by passing the goods through a dilute solution of carbonate
of soda. This colour is very fast, but is inclined to acquire a

THE ANILINE OR COAL-TAR COLOURS 41

slightly green shade by long exposure to the air. Unfortunately,
it cannot be printed on with other colours, because when steamed
the cotton is destroyed by the acid character of the mixture
employed for its formation. It can, however, be printed on at
the same time as madder mordants, and these can be afterwards
dyed with a lead mordant, so that when passed through bi-
chromate of potassium a pattern with black and yellow or orange
can be obtained.

The aniline colours have produced quite a revolution in the
arts of dyeing and printing, and have made these processes far
simpler than they were, and there is such a variety of shades of
colour now sent into the market that the dyer or printer has
little else to consider than the intensity of the colour required ;
and, in fact, if a dyer has a large order to execute of a particular
shade of colour not in the market, he will not trouble about
matching it himself, but sends to the colour manufacturer to
supply him with a product capable of yielding the required shade.

Besides dyeing and calico-printing, several other branches
of industry have benefited by the coal-tar colours, such as the
arts of lithography, type-printing, paper staining and colouring,
etc. Before they could, however, be used for these various
purposes, it was necessary that they should be made into lakes
or pigments, by union with alumina or other suitable base ; but
as most of the aniline colours are of a basic nature, it was found
impossible to combine them directly with a metallic oxide like
alumina ; advantage was, therefore, taken of their affinity for
starch granules, and some very brilliant products were obtained
by dyeing powdered starch with the cold aqueous solution of
these colouring matters. These starch powders, however, are
wanting in covering power or body, so that other processes had
to be sought for, and now these lakes are made upon an alumina
base, by the intervention of tannin or benzoic acid.

Many attempts have been made to prepare a pigment from
rosolic acid or aurine, and this, to some extent, has been accom-
plished by precipitating a solution of the colouring matter with
alumina ; by this process, a bright orange-scarlet-coloured pro-
duct can be obtained ; it is, however, only suitable for paper-
staining. I have, therefore, lately been further experimenting
in this direction, and have succeeded in forming a very brilliant
scarlet pigment, which can be used for printing-inks and a
variety of other purposes.

42 THE BRITISH COAL-TAR INDUSTRY

Upon the table there are some specimens of magenta,
Britannia violet, aniline blue, green and orange lakes, and also
some very beautiful and intense-coloured preparations of coal-
tar colours, now generally called carmines. These lakes, when
ground with printers' varnish, produce printing-inks of very
great brilliancy, and are extensively used for this purpose ; and
Mr Hanhart, whose name is so intimately connected with the
art of lithography, has most kindly furnished me with the various
illustrations of the application of these products to lithographic
printing for this lecture.

These lakes in a wet condition are being largely used for
paper-staining, and also for paper-colouring, as well as for a
variety of other less important purposes.

The peculiar bronze surface produced by evaporating a
solution of an aniline colour has been taken advantage of by the
manufacturer ; and all the bronze bonnets, hats, flowers, and
feathers, so much worn in the autumn of last year, derived their
lustre from aniline colours. When first employed for this
purpose, no fixing agent was used with them ; and as they are
mostly soluble in water, a shower of rain was often found to
cause beautiful purple drops to fall from these bronzed bonnets
and hats, and produce a kind of mottled pattern upon the white
collars, and sometimes even upon the face, of the wearer.

Aniline colours are used for writing-inks, colouring soap,
etc. ; but as these applications are only of small importance from
a commercial point of view, I will not spend time in speaking
about them.

I have in this lecture brought before you in a rapid I fear
too rapid manner an account of most of the coal-tar colours ;
but, before concluding, I should like to show you the close
relationship which exists between some of them, especially
between those derived from rosaniline or magenta.

I have endeavoured to show you that the derivatives of
magenta closely agree in properties, all of them containing
colourless organic bases, the colour being developed upon their
combining with acids. But I now wish to show you more
than this, by briefly explaining their chemical structure. To
describe this thoroughly it would be necessary for me to enter
fully into the chemical theory of substitution ; but as this would
occupy a great deal of time, I must content myself with just
mentioning a few facts connected with that subject.

THE ANILINE OR COAL-TAR COLOURS 43

Rosaniline and its derivatives contain carbon, hydrogen, and
nitrogen, as I have told you on a previous occasion. Chemical
substances containing hydrogen often hold it in what is termed
a replaceable condition, that is, in such a condition that it may
easily be removed and another substance of equal value (either
simple or compound) introduced in its place. A compound
substance, capable of replacing hydrogen, is called a " radical,"
and I want to speak about two of these radicals, one called ethyl,
and contained in iodide of ethyl, the other called phenyl, and
contained in aniline.

Ethyl contains C 2 H 5 .

Phenyl C 6 H 5 .

I will first mention a familiar instance of the replacement of
hydrogen by a radical. Water is composed of two equivalents
of hydrogen and one of oxygen, thus :

H io

H/ a

Now, it is quite easy to remove an equivalent of this hydrogen
and replace it by ethyl :

This is water with hydrogen replaced by ethyl, a replacement
compound by some very much preferred to water itself ; it is
alcohol.

Rosaniline contains three equivalents of hydrogen, replace*-
able by radicals. This is the formula of the hydrochlorate of
rosaniline, the three separate H's being replaceable :

( C 20 H 16)

Now, what takes place upon boiling this salt with aniline ?
The phenyl of the aniline simply takes the place of the replaceable
hydrogen, producing what is called triphenylrosaniline. The
result of this replacement is that the rosaniline salt has been
changed from red into blue the bleu de Lyon which is
represented thus :

44 THE BRITISH COAL-TAR INDUSTRY

Dr Hofmann, on observing this relationship, was induced to
try whether he could replace the hydrogen in rosaniline by other
radicals than phenyl. He tried to introduce ethyl by digesting
rosaniline with iodide of ethyl, and succeeded in introducing
three molecules of the radical ethyl in the place of the three
replaceable hydrogens. I will endeavour to show you how this
takes place, by the following equation :

(C 2 H 5 )I ( C 2oH 16 M HI

(C 2 H 5 )I + \N y HCl. = HI

IT ft \ T T-TT 2 5

(C 2 H 5 )I (C 2 H 5 )

Three molecules of Hydrochlorate Three of iodide of Hydrochlorate of

iodide of ethyl. of rosaniline. hydrogen or triethylrosaniline.

hydriodic acid.

Here we see the iodine has simply exchanged its ethyl for
the replaceable hydrogen of rosaniline, and the result is a blue
shade of the Hofmann violet.

Now, it is not necessary to replace the three hydrogens ; two
may be replaced, and we get a less blue violet. Represented
thus :

Hydrochlorate of
diethylrosaniline.

Or one may be replaced, and we get a red violet. Represented
thus :

(C 2 oH 16 )

(C 2

Hydrochlorate of
ethylrosaniline.

When speaking of the violet imperial, I mentioned that it
consisted of products intermediate between rosaniline and the
bleu de Lyon. These intermediate substances consist of ros-
aniline with one or two equivalents of hydrogen replaced by
phenyl.

Up to the present moment it has only been found possible
to replace one equivalent of hydrogen in mauveine, or the mauve
dye, and, as I previously mentioned, it is curious that the result

THE ANILINE OR COAL-TAR COLOURS 45

of this replacement is perfectly opposite to that which takes
place in the case of rosaniline, the replacement of hydrogen by
ethyl in rosaniline causing it to become bluer in shade, and the
replacement of hydrogen by ethyl in mauveine causing it to
become redder in shade. The following is the formula of the
hydrochlorate of ethyl-mauveine or dahlia :

But although I have tried to explain the relationship of these
colouring matters as simply as I can, yet this part of my lecture
assumes much of the character of a lecture on theoretical
chemistry. Here we are talking about substitution products
of bodies, a branch of the highest theoretical chemistry, and it
must strike us as remarkable when we find that these considera-
tions have been pressed upon us by the discussion of bodies
which may now be said to be common dyestuffs. We have
also been talking in quite a familiar manner about nitrobenzol,
aniline, iodide of ethyl, aldehyd, etc., substances which were,
only a few years since, the recherche compounds of the laboratory.
In fact, the coal-tar colour industry is entirely the fruit of theo-
retical chemistry. Let us consider the enormous rapidity with
which this industry has developed. It only dates from 1856,
and now (in 1868) we have large factories for the production
of coal-tar colours, not only in Great Britain, but in Germany,
France, Switzerland, America, and other countries. I had hoped
to have been able to give you a statistical account of this industry,
but have not had sufficient time for this purpose. Dr Hofmann,
however, in his report on the coal-tar colours shown at the Paris
Exhibition of 1867, remarks that "in 1862, the value of these
manufactures had risen from nothing to 10,000,000 francs,
or more than 400,000 sterling. At the present day this sum
is trebled, which would make it about one million and a quarter
pounds sterling, although the products are much cheaper than
they were before." And, now, when you hear of these results,
do not forget that they are the truly practical fruits of theoretical
chemistry, not studied for the purpose of producing commercial
products, but simply for its own sake.

II. : i8 7 o

THE ARTIFICIAL PRODUCTION OF
ALIZARINE

BY PROFESSOR H. E. ROSCOE, F.R.S.
(Discourse delivered at the Royal Institution, ist April 1870)

THE discovery of artificial alizarine, whether we regard its
scientific interest or its practical and commercial value, is of
the highest importance, and marks an era in the history of the
application of chemistry to the arts and manufactures even
of greater importance than the memorable discovery made by
Mr Per kin in 1856 of the production of aniline violet, or
mauve.

Since the above-named year great progress has been made in
the theoretical investigation of natural and artificial colouring
matters, as well as in their preparation on a large scale. The
chemistry of colouring matters has now taken a high and im-
portant position, and chemists, instead, as formerly was their
wont, of getting rid of all colouring matters as something foreign
to their objects of investigation, have, since Mr Perkin's dis-
covery, found out that the examination of colouring matters may
not only lead to scientific laurels, but may sometimes yield fruit
of another and not less acceptable kind.

We owe to the brains and hands of two German chemists,
Graebe and Liebermann, this remarkable discovery, which differs
from all the former results which have been brought about by
the application of science to the chemistry of colouring matters,
inasmuch as this has reference to the artificial production of a
natural vegetable colouring substance which has been used as a
dye from time immemorial, and is still employed in enormous
quantities for the production of the pink, purple, and black

4 6

THE ARTIFICIAL PRODUCTION OF ALIZARINE 47

colours which are seen everywhere on printed calicoes, viz.
alizarine, the colouring principle of madder.

It is from the liquid tarry products of the destructive distilla-
tion of coal, a rich source of interest to chemists, that we now
derive this new colouring matter.

The following table contains the results of experiments made
on a large scale, indicating the various yields of tar from
different qualities of coal distilled in the gasworks of various
towns :

DESTRUCTIVE DISTILLATION OF COAL
100 tons of cannel and bituminous coal yield the following products:

Gas.

Tar.

Ammonia
water.

Coke.

22-25

8-50

9'5

5975

Average of many

experiments.

20*01

7-85

7-14

65*00

Manchester.

2O'4O

6-4

5-4

67-85

Dukinfield.

21'7

7'5

5'8

65*0

Macclesfield.

I6'3

10-7

8-0

65*0

Salford.

From a careful series of experiments made by a large tar
distiller the following numbers are derived, showing the average
composition of gas tar :

ioo tons of coal-tar on distillation yield :

Naphtha.

Light oils
and carbolic
acid.

Heavy oils,
naphthalene,
anthracene.

Pitch.

Water, gas,
and loss.

3*o
3'

i'S

0-8

35*
25-0

5o*o
60*0

10-5
12*2

It is from benzol, C 6 H 6 , discovered by Faraday in 1825, that
the aniline colours are all of them prepared. The colour-produc-
ing powers of the coal products are, however, yet far from being
exhausted. It is by means of another and hitherto comparatively
unknown hydrocarbon, anthracene, C^Hjo, that the newest

4 8 THE BRITISH COAL-TAR INDUSTRY

triumphs of the chemist have been won. This is a substance
which in the pure state few chemists have seen (1870), and
upon which only two or three had previously experimented ; and
yet by one happy discovery and by an investigation which more
than almost any other exhibits the value of the synthetic power
of modern research this unknown body has been made to yield
a colouring matter of the greatest possible value. The truth of
this will at once be evident when we learn that the total growth
of madder is estimated to reach 47,500 tons per annum, worth
45 per ton, and having, therefore, a value of ^2,150,000. Of
this nearly one-half is used in the United Kingdom, so that no
less a sum than j 1,000,000 is now paid by us for madder grown
in foreign countries. This will now, in part at least, go to
benefit our own population, as we can now transform our coal
into this invaluable colouring matter.

In an experiment made on a large scale it was found that
100 tons of tar yield 0*63 ton of anthracene, or i ton of
anthracene can be obtained from the distillation of about
2000 tons of coal, not reckoning the quantity of anthracene con-
tained in the pitch.

Madder is the root of several species of Rubia y amongst
which the R. tinctorium is the most valued for its dyeing properties.
This grows in Holland, Asia Minor, and in the south of France
and of Russia. A species native to England is the R. peregrina.
This belongs to the order Rubiace<e, the native members of which,
as the Galiums, are mostly inconspicuous wild plants. Some of
the foreign species are, on the contrary, important plants, such as
the cinchona, ipecacuanha, and coffee plants, and these are dis-
tinguished for the number and variety of the peculiar principles
which they yield, as quinine, cinchonine, caffeine, alizarine.
(Thanks to the kindness of Dr Schunck, the speaker was able to
show a young madder plant.)

In spite of the many investigations of madder which have
been made, chemists are still in doubt as to the nature of many
of its constituents. Some attribute its colouring powers to the
presence of at least two substances alizarine and purpurine ;
whilst others say that only one of these produces the true
madder colours.

Alizarine was discovered and obtained from madder, as a
crystalline sublimate, by Robiquet and Colin in 1831 ; but little
importance attached to this discovery until Schunck, in 1848,

THE ARTIFICIAL PRODUCTION OF ALIZARINE 49

showed that all the finest madder colours contain only alizarine
combined with bases and fatty acids. The second colouring
matter, termed purpurine, was discovered by Persoz. It con-
tributes to the full and fiery red colour in ordinary madder dye-
ing, but dyes a bad purple, alizarine being essential to the latter.
Purpurine disappears during the purifying processes of soaping,
etc., being far less stable than alizarine. It is distinguished from
alizarine by its solubility in boiling alum liquor.

These two colouring principles may likewise be easily dis-
tinguished by their spectra, alizarine producing a set of dark
absorption-bands, quite different from those of purpurine, which
again vary according to the solvent. Alizarine can be obtained
in yellow needle-shaped crystals by simple sublimation from the
dried madder ; but this colouring matter is, singularly enough,
not contained ready formed in the fresh madder root, but is the
product of a peculiar decomposition. For a proof that fresh
madder does not contain alizarine we have only to extract the
moist root with alcohol, when neither the alcoholic extract nor
the insoluble residue will be found to possess tinctorial power.
We owe this knowledge to the researches of Schunck and
Higgin, who have proved that alizarine is produced by a
peculiar kind of fermentation which partly occurs in the root on
standing, and partly takes place in the dyebeck, when the powdered
madder is treated with water. A crystalline glucoside, termed
rubianic acid (Schunck), is contained in the root, and it is this
which splits up simply into alizarine and glucose. This acid crys-
tallises in fine yellow needles, and gives a definite and crystalline
potash salt, from which it was shown to contain twenty-six atoms of
carbon in the molecule. Hence, as no other product but glucose
is formed, it follows that alizarine must contain C 2 e C 12 =C 14 .
(This decomposition of rubianic acid into alizarine was shown by
boiling with an acid, and adding caustic soda, when the blue
solution of alkaline alizarate was seen.) The formation of ali-
zarine in extracts of madder root is effected by a ferment peculiar
to the plant and called Erythrozym. It is a ferment sui generis,
since no other ferment produces the same effect. When mixed
with a solution of rubian or rubianic acid, at the ordinary
temperature, the latter is rapidly decomposed as with acids.
This is what takes place in making fleur de garance. Dyers
raise the temperature of their madder-baths gradually up to
boiling-point, because the application of a high temperature

50 THE BRITISH COAL-TAR INDUSTRY

destroys the ferment. When the temperature is gradually raised,
the ferment acts upon the glucoside, and produces alizarine.

That the colouring matter in fresh madder root is not
alizarine can be easily shown by rubbing the soft portions of
the root on to paper, when a yellow stain will be produced,
which, on treatment with an alkali, shows the bright red colour
of an alkaline solution of rubian instead of the blue solution
of alizarate.

According to Schunck, the origin of purpurine, and its relation
to alizarine, are still involved in obscurity.

The hypothesis which of late years has done more than any
other to stimulate experiment and enlarge our views in organic
chemistry is undoubtedly Kekule's theory of the tetrad nature of
carbon and his explanation of the constitution of the carbon
compounds. In the so-called paraffine group of organic sub-
stances, the carbon atoms are supposed to be connected together
by single links of the four bonds attached to each atom, thus
giving rise to saturated compounds by the attachment of other
elements or radicals to the free bonds. In the group of aromatic
substances with which we are specially concerned the carbon
atoms are more closely linked together, or, in other words,
fewer atoms of hydrogen are necessary to saturate an aggrega-
tion of carbon atoms than is the case in the other group. We
can explain this, upon the assumption of the tetrad character
of carbon, by supposing that each carbon atom is attached to
its neighbour alternately by one and two bonds.

Another singular property of these aromatic bodies is that
they all contain at least six atoms of carbon, and that the simplest
hydrocarbon of which they are made up is benzol, C 6 H 6 . So
that we may regard all these aromatic compounds as benzol
derivatives, and this hydrocarbon may be considered as the
skeleton round which many complicated substances are arranged.
So that by the replacement of one atom of hydrogen by (NH 2 )
we obtain aniline, or by (OH) phenol, etc. From the knowledge
gained by the investigation on the quinones, Graebe came to
the conclusion that alizarine belongs to the quinone series ; and,
availing themselves of Baeyer's reaction, by which phenol can
be converted into its hydrocarbon benzol, Graebe and Liebermann
passed the vapour of natural alizarine obtained from madder
over heated zinc-dust, and found that the hydrocarbon they
formed was identical in all its properties with anthracene,

THE ARTIFICIAL PRODUCTION OF ALIZARINE 51

C 14 H 10 , from coal tar. Hence they confirmed Schunck's con-
clusions that the molecule of alizarine contained fourteen atoms
of carbon. Having thus got hold of the backbone, as it were,
of the compound, it only remained for them to clothe the
hydrocarbon with the four additional atoms of oxygen, and to
take off the two atoms of hydrogen in excess, in order to obtain
alizarine.

Laurent and also Anderson had, many years ago, obtained
a body of the composition C 14 H 8 O 2 , and Graebe recognised this
as the quinone of anthracene ; and he now only required to re-
place in this two atoms of hydrogen by two of hydroxyl (OH),
in order to obtain alizarine, which clearly appeared to be a
quinone acid

C 14 H 10 C 14 H 8 (0") 2 C 14 HOH

(OH

Anthracene Anthraquinone Alizarine.

This replacement of hydrogen can be effected by bromine, by
which bibromanthraquinone, Ci4H 6 Br 2 O 2 , is formed, and this,
on fusion with caustic potash, gives potassium alizarate, yielding
pure alizarine on treatment with hydrochloric acid. The high
price of bromine rendered this process unavailable for manu-
facturing purposes, and hence another plan was simultaneously
proposed by several chemists for effecting the same end in a
cheaper mode. Use was hereby made of Kekule's and Wurtz's
reaction in the formation of sulpho-benzoic acid. On treating
anthraquinone with strong sulphuric acid to a high temperature,

the di-sulpho acid C 14 H 6 O 2 -jgQ 3 TT is formed, and this, on

heating with concentrated solution of potash, yields the sulphite
and alizarate of potassium ; from the latter substance pure
alizarine is obtained by the action of acids.

In the following table we have a statement of the synthetic
production of alizarine from its constituent elements :

SYNTHESIS OF ALIZARINE

1 . Acetylene by direct union of carbon and hydrogen in electric arc :

C 2 + H 2 = C 2 H 2 . (Berthelot, 1862.)

2. Benzol (tri-acetylene) from acetylene by heat :

C 6 H 6 . (Berthelot, 1866.)

52 THE BRITISH COAL-TAR INDUSTRY

3. Anthracene from benzol and ethylene :

(Berthelot, 1866.)

4. Alizarine from anthracene (Process No. i).

(Graebe and Liebermann, 1869.)

(A) Oxyanthracene or anthraquinone by nitric acid :

C 14 H 6 (OH) 2 . (Anderson, 1861.)

(B) Bibromanthraquinone by action of bromine :

C 14 H 8 O 2 + 2Br2 = C 14 H 6 Br 2 O 2 + 2BrH.

Potassium alizarate.

5. Alizarine from anthracene (Process No. 2) :

(Graebe and Caro, Perkin, Schorlemmer and Dale.)

(A) Disulphoanthraquinonic acid from anthraquinone :
C 14 H 6 (OH) 2 + 2 H 2 S0 4 = C U H 6 2 + 2 H 2 O.

(B) Alizarine from the above by the action of potash :
C 14 H 6 2 + 4 KHO - C 14 H 6 2

Alizarine.

Mr Perkin states that an intermediate substance is formed in
this reaction having the formula C 14 H 6 (O) 2 "s OQO , and this,

when heated with potash, splits up into alizarine and a sulphite.
Other yellow-coloured products are, according to Perkin, con-
tained in the alizarine as sent out from his manufactory. The
nature of these yellow crystalline bodies is as yet unknown.

Of the identity of the natural with the artificial alizarine
there can be no doubt ; they agree in all their physical and
chemical properties. Their absorption-spectra are identical,
their tinctorial powers are the same ; the coloured lakes which
they form with alumina, iron, and copper salts are of the same
tint and possess the same degree of solubility, and these remain
alike unaltered by the action of light, so that when they are
fixed in the cotton-fibre they yield equally fast colours.

It is difficult to predict how far the artificial alizarine will
in future restrict the growth of madder ; but there is no doubt
that for many styles of calico-printing the artificial alizarine is
of the greatest value, and we may naturally expect to see very

THE ARTIFICIAL PRODUCTION OF ALIZARINE 53

important changes effected in this branch of chemical industry
in the further practical application of this new discovery.

CONTRIBUTIONS TO THE HISTORY OF ALIZARINE, C 14 H 8 O 4

1825. Faraday discovered benzol, C 6 H 6 , in coal-gas oil.

1831. Robiquet and Colin discovered alizarine in madder root.

1832. Dumas and Laurent discovered anthracene in coal oils.
1848. Schunck gave the composition of alizarine, C 14 H 10 O 4 .
1850. Strecker gave the composition of alizarine, C 10 H 6 O 3 .
1862. Anderson examined anthracene compounds, C 14 H 10 .

1865. Kekule explained the constitution of the aromatic compounds.

1866. Baeyer obtained benzol from phenol.
1868. Graebe investigated the quinones.

1868. Graebe and Liebermann obtained anthracene from alizarine.

1869. Graebe and Liebermann obtained alizarine from anthracene.

III.: 1879

THE HISTORY OF ALIZARIN AND ALLIED
COLOURING MATTERS

BY W. H. PERKIN, F.R.S.

(Journal of the Society of Art *, 1879, p. 572)

THIS paper gives a very detailed and complete account of the
history and synthetic production of alizarin. The main points are
summarised in the " Hofmann Memorial Lecture" delivered by Dr
Perkin before the Chemical Society in 1896, and reprinted in the
present work (see p. 141).

The ground covered by Perkin' s 1879 r lecture is indicated by the
following headings :

History and Applications of Madder.

Schunck's Researches on " Natural Alizarin."

Graebe and Liebermann's Researches.

Graebe and Liebermanns First Synthesis ^Bromine process).

The Sulphonic Acid Process (Perkin^ Graebe and Liebermann,

Caro).

Impurities in Synthetic Alizarin.
Alizarin Orange and Alizarin Blue.
The History of the Technical Manufacture of Alizarin in

Perkins works.
The Constitution of Alizarin.

The concluding paragraphs only of this interesting paper are
quoted :

Having now given an account of the manufacture of artificial
alizarin, it will be interesting to inquire into the commercial
results of this industry, and, firstly, what has been its influence
upon the sale of madder and its derivatives. I mentioned at the

THE HISTORY OF ALIZARIN

commencement of this paper that the annual value of the im-
ports into the United Kingdom, of madder and garancine, from
1859 to 1868, amounted to about 1,000,000 sterling, with prices
averaging for madder 455. to 505. per cwt., and for garancine,
1505. In the subjoined table will be seen the remarkable
changes that have taken place in the imports, and also the great
reduction in price :

AVERAGE ANNUAL IMPORTS OF MADDER AND GARANCINE
INTO THE UNITED KINGDOM

Year.

Madder.

Garancine.

French
madder.

Turkey
roots.

Garancine.

cwts.

1859)
1868 j

35> 8 40

45>56o

45s.

5 os.

1508.

1875

100,280

25,860

1876

59i*37

I5>396)

or V

6,436)

1877

38,711

8,875

1878

32,990

2,79

1 8s.

175.

6 5 s.

Up to and during 1876 considerable quantities of artificial
alizarin were imported from the Continent, and entered at the
Customs as garancine or madder, and this having been brought
to the notice of the officials, the returns made subsequently are
more reliable. The imports of garancine were returned by the
Board of Trade in 1876 as 15,396 cwts. when first published,
but in the following year, when the figures for 1876 were given
for comparison with those of 1877 and 1878, the returns were
stated as only 6436 cwts. The erroneous entries were most
probably made to evade the penalties for the infringement of
patent rights. 1

Dutch ground madder has been relatively much higher in
price than the other qualities. This is owing to its extensive
use in wool dyeing. For various reasons artificial alizarin has
made but little progress in its application to wool dyeing, and

1 A method so often resorted to as to render English chemical patents
nearly useless as a protection against infringements by foreign manufacturers,
the results of this being alike detrimental to the inventor and injurious to the
national interests.

56 THE BRITISH COAL-TAR INDUSTRY

Dutch madder being mostly used for this purpose, its prices
have been maintained at from 28s. for ordinary " Ombro " to
about 405. to 455. for crop madder. The wool dyers have,
however, been working cautiously with artificial alizarin, and
now some of them are using it somewhat largely, and considering
its cheapness as compared with Dutch madder, no doubt they
will soon find how to use it successfully and cease to employ
madder.

The decline in the sale of madder is still rapidly going on.
During the first two months of last year the imports were

Madder 6846 cwts.

Garancine 533

During the first two months of this year they were

Madder 2185 cwts.

Garancine 175

or about two-thirds less. And not only so, but the price is still
declining. Turkey roots may now be bought at us. per cwt.,
whereas before artificial alizarin was introduced they were sold,
on an average, at 505. At the present prices of madder, its
cultivation is unremunerative, and will, undoubtedly, be soon a
thing of the past. Such has been the success of artificial alizarin
in competing with madder and garancine in this country, and it
is equally true of other countries. The quantity of madder
grown in all the madder-growing countries of the world prior to
1868 is estimated at about 70,000 tons per annum. The amount
of artificial alizarin now produced is equal in dyeing power to
considerably more than this ; in fact, the lowest estimate I have
been able to get for 1878, and which was confirmed from other
sources, is 9500 tons, which is equivalent to 950,000 tons of
madder. This remarkable result has been arrived at in ten
years only.

To produce this quantity of artificial alizarin, there are about
nine manufacturers on the Continent, and one in this country,
Messrs Burt, Bolton & Haywood, who have two large works
for its production, viz. the original works at Greenford Green,
and new ones at Silvertown.

Graebe and Liebermann, in their paper in the Moniteur
Scientifique?- give some statistics of the production of artificial

1 Moniteur Scientifique, April 1879, 416.

THE HISTORY OF ALIZARIN

alizarin which, however, require correcting. They also leave
out the years 1869 and 1870. In 1869 we had advanced in the
manufacture so far as to send colour into the market, the first
invoice being dated October 4th, and that year we produced
about one ton. In 1870 we produced 40 tons ; in 1871, 220
tons ; in 1872, 300 tons ; and in 1873, 435 tons. Up to the
end of 1870 we were practically the only makers of this product,
one of the largest chemical and coal-tar colour manufacturing
firms of Germany, with whom we were in correspondence, stating
that in November 1870 they had only lately commenced pro-
ducing 50 Ibs. of alizarin, 10 per cent, quality, per day, and that
no one else in that country was supplying artificial alizarin ; and
in 1871 we were practically the only producers of quantity, at
any rate during the first part of the year, for in March 1871
the firm already referred to, and who had great opportunities of
knowing what was being done in their country, wrote that they
had not received knowledge of any establishment but their own
manufacturing artificial alizarin.

In November 1871, however, Messrs Gessert Fr&res
announced to the Industrial Society of Mulhouse that they had
produced 30,792 kilogrammes of alizarin in paste. This is
equal to about 30 tons, an amount which was evidently con-
sidered by them a very large quantity. 1

Graebe and Liebermann's statistics are as follows compared
with our production :

Graebe and Perkin & Sons'

1869
1870
1871

1872
1873

Liebermann. productions.

Tons. Tons.

125- 150 220

4OO- 5OO 300

900-1000 435

Without wishing to detract from Graebe and Liebermann's
original discovery, we may say, that the birthplace of the manu-
facture of artificial alizarin was in England. It was in this
country that the difficulties and doubts about the manufacture
and supply of the raw material, anthracene, were solved, and
the production of artificial alizarin by new processes success-
fully accomplished. After these results were obtained in this
country, Continental chemists were encouraged to manufacture

1 Moniteur Scientifique^ April 1879, 416.

5 8 THE BRITISH COAL-TAR INDUSTRY

on a comparatively large scale, but up to the end of 1873 the
English manufacturers had practically no competition in the
home market.

Having considered the amount of artificial alizarin now manu-
factured, it will be of interest to see what its money value is.

Taking the lowest estimate, viz. 9500 tons, and calculating
its selling prices at 150 per ton, the annual value amounts to
no less than 1,425,000, or nearly a million and a half.

As a dye, it is now at most not more than one-third of the
average price of madder in 18591868. Consequently, in the
United Kingdom, when the annual value of madder imported
was 1,000,000, the annual saving is very great.

While collecting the statistics about alizarin, I thought it
would be of interest to get, if possible, the statistics of the entire
coal-tar colour industry, and to the kindness of H. Caro, of the
Badische Anilin und Soda Fabrik, I am indebted for most of
the following particulars :

ESTIMATED VALUE OF THE PRODUCTION OF COAL-TAR
COLOURS IN 1878

Germany . . ^2,000,000, of which four-fifths are exported.

England . . 450,000

France . . . 350,000

Switzerland" . . 350,000

Total . . .3,150,000

In referring to the works which have been set up for the
purpose of making coal-tar colours, I thought it would be of
interest to show a copy of a rough sketch of the first works
erected for this purpose as they appeared in 1868, two years
after the patent for the mauve was taken out.

These works were not one year old when sketched, and the
practicability of making the mauve commercially had only been
proved a short time. In 1873 they had increased to such an
extent as to cover about six acres. They are represented at this
date by a copy of a photograph. 1

There are now in this country six coal-tar colour works ; in
Germany, no less than seventeen ; in France, about five ; and in

1 A copy of a photograph of the works as they appeared in 1873, and a
facsimile of the sketch referred to in the text, showing the works in 1858, is
given in a lithograph issued as a supplement to the Journal of the Society of
Arts, May 3oth, 1879.

THE HISTORY OF ALIZARIN 59

Switzerland, four. There are also three works in Germany and
three in France which manufacture aniline in enormous quantities
for the production of coal-tar colours.

Such is the wonderful growth of this industry, which dates
only from 1856. It is the fruit of scientific researches in organic
chemistry, conducted, mostly, from a scientific point of view ;
and, while this industry has made such great progress, it has, in
its turn, acted as a handmaid to chemical science, by placing at
the disposal of chemists products which otherwise could not have
been obtained, and thus an amount of research has been con-
ducted through it so extensive that it is difficult to realise, and
this may, before long, produce practical fruit to an extent we
have no conception of. One very important colouring matter
related to coal tar, and one of the original sources of aniline a
product of as great importance as alizarin has yet to be pro-
duced on the large scale. I refer to indigo. Baeyer has shown
that it can be produced artificially, but at present no practical
means of accomplishing it have been discovered. No doubt,
however, it will not be many years before this is achieved, and
the cultivation of the indigo plant shares the fate of madder.

The Chairman, Prof. F. A. ABEL, C.B., F.R.S., said Mr
Perkin had dwelt with very justifiable pride on the fact that
England had been the birthplace of this particular branch of
industry connected with the coal-tar colours, of which he had
given the history in so lucid a manner. He had not, however,
recalled to their minds that which was also true, that England
was also the birthplace of the entire coal-tar industry, the
development of which he had so graphically and clearly narrated.
He had also, with the modesty which they all knew him to
possess, forgotten to mention that he himself was the inventor
and founder of this industry, which must compete in importance
and interest with any other industry, either in England or any
part of the civilised world.

IV.: i88o

THE NEWER ARTIFICIAL COLOURING
MATTERS DERIVED FROM BENZENE

BY R. J. FRISWELL, F.C.S., F.I.C.

(Journal of the Society of Arts^ 1880, p. 444)

METHYL ANILINE VIOLETS

IT is, no doubt, well known to many here that the earliest
violets obtained by artificial means were those produced by the
action of pure aniline, or phenylamine, on roseine (magenta),
in the presence of an organic acid. A study of this reaction
by Hofmann led to his discovery of the action of the iodides of
the alcoholic radicals, methyl and ethyl, on roseine base, with
the production of the well-known " Hofmann Violets." These
were found to be substitution-products of rosaniline, in which
one, two, or three atoms of hydrogen in the molecule are
replaced by the radicals methyl or ethyl, according as the
iodide of either has been used.

Now roseine itself is, as is well known, produced by the
action of arsenic acid or other oxidising agents on a mixture
of aniline and toluidine. The chemical formula then adopted
for it led to the conclusion that it was produced by the
coalescence of the residues of two molecules of toluidine and
one of aniline, thus :

C 6 H 5 NH 2 + 2 C 6 H 4 CH 3 NH 2 - H 6 = C 20 H 19 N 3 .

O. and E. Fischer have recently shown that this formula was
partly erroneous, and that the reaction could also occur between
two molecules of aniline and one of paratoluidine

2 (C 6 H 5 NH 2 ) + C 6 H 4 CH 3 NH 2 - H 6 - C 19 H W N 8 ;

NEWER ARTIFICIAL COLOURING MATTERS 61

but this does not affect the inference drawn from what was, till
recently, supposed to be the constitutional formula of the body
in question, and this inference was that the methylated
derivatives of roseine could be obtained by the oxidation of
the methylated derivatives of aniline, just as roseine was by the
oxidation of aniline and toluidine. The inference was somewhat
rash ; the methyl groups in dimethylaniline replace the hydrogens
in the amido group, and on oxidation might, perhaps, be
destroyed. However, on oxidation, dimethylaniline did, indeed,
produce a very brilliant violet colour, which, having been
discovered by M. Lauth, and improved and patented by Messrs
Poirrier & Chappat, was introduced into commerce under the
name of Paris Violet. This achievement led to a demand for
the production of the methyl anilines on a large scale, and, in a
very short time, this was attained. It was well known that
methylaniline could be produced by the action of methyl iodide,
or bromide, upon aniline, the dimethyl compound resulting
from the use of two molecules of the alcoholic compound ; thus

C 6 H 5 NH 2 + 2(CH 8 I) = C 6 H 5 N(CH 3 ) 2 + 2 HI ;

but it was evidently necessary to produce the required compound
in a cheaper way. This was eventually done by heating aniline
hydrochloride and methylic alcohol together, under pressure, in
strong cast-iron vessels, enamelled inside, and known as
" autoclaves." Various proportions of the bodies have been
employed among others, the following giving good results :
Aniline, 33*6 ; hydrochloric acid, 37*9 ; methylic alcohol pure,
28-5 ; heat to 250 C. for eight hours. Messrs Poirrier have
also employed a mixture of 100 parts aniline and 250 methyl
nitrate. In the latter case, the mixture requires only a temperature
of 1 00 C. ; but the alcoholic nitrate is an exceedingly dangerous
compound to deal with ; in all probability, it was the one that
led to the lamented death of Mr E. T. Chapman, and a very
disastrous and fatal explosion at Messrs Poirrier's works was
also caused by it.

Methylaniline is now largely made by the action of methyl
chloride on aniline. As is well known, the former body has,
of late years, been obtained in immense quantities in France,
from a product of the destructive distillation of residues obtained
in the manufacture of beet sugar. This body reacts upon
aniline just as the corresponding iodide or bromide does ; it is

62 THE BRITISH COAL-TAR INDUSTRY

cheap, the reaction takes place with ease, and a remarkably
pure product is produced : in fact, dimethylaniline can now be
obtained by the ton, free from unaltered aniline, and containing
only 3 per cent, of the monomethylated compound.

From dimethylaniline the violet is obtained by oxidation ;
formerly, various oxidising agents were used, among them a
mixture of iodine and potassium chlorate ; it is, however, now
well known that very gentle oxidisers will produce the colour
if a metallic salt is present, the one preferred being copper. If
I heat, in this tube, some copper filings with a mixture of
dimethylaniline and chloral hydrate, the whole will shortly
become a mass of semi-solid violet. It is, however, obvious
that so costly a method could not be employed on a manufacturing
scale, and, accordingly, the following process is in very general
use : 20 parts pure crystallised cupric nitrate are dissolved
in 20 parts of acetic acid ; some common salt is now stirred in
to the mixture, which is carefully cooled down to the ordinary
temperature, and 50 parts of dimethylaniline are added ; the
whole is then thoroughly mixed with about 250 to 300 parts
of white sand, and the stiff mass thus produced is moulded into
large cakes, 2 feet long by 15 inches wide, and 4 inches thick ;
these, arranged on copper plates, are placed in a chamber, and
heated to a temperature of 60 C. for forty-eight hours. At the
end of that time, they have become perfectly hard and brittle,
and of a bright brassy colour. They are broken into a coarse
powder and thrown into water, sulphide of sodium being added
until the whole of the copper-salt has been decomposed. The
mass is now washed with water and extracted with dilute hydro-
chloric acid at a boiling temperature. After partial cooling and
filtration, to remove some resinous bye-products, the colouring
matter is precipitated with common salt, and, after drying, it is
ready for use. The sand, which simply serves to spread the
mixture over a large surface, can be used for a fresh operation.

The product thus obtained is very brilliant in colour, and
in shade is that known as 3 B, dahlia, etc. ; it is, however, not
the bluest that can be produced. The bluest shades are made
by dissolving it in alcohol, converting it into base by the cautious
addition of caustic soda, and then heating the alcoholic solution
of the base with benzyl chloride a body having the formula
C 6 H 5 CH 2 C1, and produced by the action of chlorine on
toluene. The spirit and unaltered benzyl chloride are re-

NEWER ARTIFICIAL COLOURING MATTERS 63

covered, and the basic colour, on conversion into the hydro-
chloride, is ready for use. In a similar way, by the action of
methyl chloride, the well-known methyl green was produced ;
it is now, however, replaced by the malachite green, discovered
by Oscar Doebner, and produced by the action of one molecule of
benzoyl trichloride, C 6 H 5 CC1 3 , on two molecules of dimethyl-
aniline or of benzoylhydride, or bitter almond oil, C 6 H 5 COH, on
the same, in the presence of zinc chloride or of sulphuric acid.

The latter colour much surpasses the former in fastness and
power of standing rough treatment in the dyeing process. The
methyl, and, still more, the iodine green, obtained during the
manufacture of blue shades of Hofmann violet were fugitive and
easily altered by heat, so that the latter could not be boiled
without changing to a violet.

Before leaving the methylaniline colours, I may briefly allude
to a question of scientific interest in connection with them. It is
well known that Hofmann himself, at one time, considered the
violets obtained by the methylation of rosaniline and those from
methylaniline to be identical. On the other hand, there was
much evidence against this view, for the methylaniline colour
was readily rendered bluer in shade by benzyl chloride, which
was almost without action on Hofmann violet ; it was also more
brilliant, had a much greater affinity for animal fabrics, and was
less permanent when exposed to light. For these reasons, the
Hofmann colour is still in demand, and, indeed, has recovered
some of the ground it at first lost to the more brilliant colour.
The researches of Brunner and Brandenburg, following those of
Caro and Graebe, have shown that the methylaniline violets are
not identical with those obtained by Hofmann's process.

DlPHENYLAMINE BLUE AND ALKALI GREEN

The ordinary aniline blues are obtained by the action of
aniline upon roseine base, in the presence of an organic acid, at a
temperature which ultimately approaches the boiling-point of
the aniline used. The ultimate product of this reaction is an
exceedingly intense blue, the hydrochloride of which is known
as opal blue, and is, really, the hydrochloride of triphenylrosaniline.
This, on dry distillation, yields diphenylamine, and the latter
body, on oxidation, yields a blue which is identical with that
obtained from rosaniline, but somewhat greener in shade, and is

64 THE BRITISH COAL-TAR INDUSTRY

therefore in demand for certain uses. The diphenylamine is
prepared by heating, under pressure, a mixture of aniline and dry
aniline hydrochloride, when the following reaction occurs :

C 6 H 5 NH 2 + C 6 H 6 NH 2 HC1 = (C 6 H 5 ) 2 NH + NH 4 C1.

Diphenylamine is readily oxidised if heated with oxalic acid, and
the resulting melt, purified from unaltered oxalic acid, diphenyl-
amine, and resinous matters, is readily converted into either of
the sulphonic compounds discovered by Nicholson. Blues of a
redder shade can be also obtained by the oxidation of methyl- or
ethyldiphenylamine.

I have now to call your attention to a green obtained from
this body, discovered by Mr R. Meldola, and now under his
investigation. It is obtained by the oxidation of a diphenylamine
derivative. After oxidation the colour is obtained in a state
corresponding to the well-known opal blue, and, like that, forms
sulphonic acids. It is remarkable as being the first green obtained
having this property. The sodium salt of the sulphonic acid is
soluble in water, and, if wool is immersed in this solution (which
is nearly colourless), and kept warm, it apparently undergoes but
slight change. I have here a piece of Berlin wool which has
been thus treated, and subsequently dried. You will observe
that it is, apparently, only rather dirtier than undyed wool.
When, however, I immerse it in warm water, acidulated with
sulphuric acid, a brilliant green is immediately developed. The
colour is remarkably fast ; and, since it requires exactly the same
dyeing process as do the Nicholson blues for wool, one would
have supposed that it would have been much liked by the dyers ;
but this is not, at present, the case. It was exhibited at the late
Paris Exhibition by the firm of Brooke, Simpson, & Spiller.

As time is getting on, I must now leave this very interesting
field the colours produced by the oxidation of the secondary and
tertiary amines after a very brief and incomplete glance at a few
of them, and pass on to the consideration of a totally distinct
group of colouring matters, which are now attracting much
attention in colour-chemists' laboratories, and which have already
taken an important place among artificial dyes, though, as yet,
the range of shades is somewhat limited. These are obtained
from substances produced by the action of nitrites on amido
compounds, and are known as the azo yellows, oranges, and
scarlets.

THE NEWER ARTIFICIAL COLOURING MATTERS 65

The effect of nitrites on organic compounds is very various,
according to the subsequent treatment they undergo ; thus, if
nitrous gas is passed through a solution of diphenylamine in
acetic acid, a mixture of nitroso-nitro-diphenylamines results, and
this, on heating with an alkali, decomposes so far as the nitroso
groups are concerned, and a mixture of mono- and dinitro-
diphenylamine results, which was introduced as a yellow dye by
Mr R. Meldola. A somewhat similar reaction occurs if the
sulphonic acid of alpha-naphthol is similarly treated, and dinitro-
naphthol may be obtained ; while, if a nitrite is added to an
aniline salt, and the resulting compound boiled, or if rosaniline
salts are similarly treated, the whole of the nitrogen is eliminated
with effervescence, and phenol in the one case, rosolic acid in the
other both of them non-nitrogenous substances result. Before
this boiling takes place, there are, however, in the two latter cases,
very different bodies in solution ; these bodies, which behave in
the manner just mentioned on boiling, are known to chemists as
" azo compounds."

In the earlier days of organic chemistry, the prefix " azo "
was applied by Mitscherlich, Laurent, Zinin, and others to
many bodies containing nitrogen, such as azo - benzene,
C 6 H 5 N=NC 6 H 5 , produced by the imperfect reduction of nitro-
benzene, and also to others, like the compounds obtained by
Laurent by the action of ammonia on bitter-almond oil and
other bodies. In 1864, however, P. Griess published a
magnificent memoir, in which he described a number of bodies
obtained by the action of nitrous acid on aniline, and various
substitution-products obtained therefrom. In this paper, he
proposed that the prefix " azo " should be held to mean that
the compound to which it was applied contained one atom of
nitrogen occupying the place of one atom of hydrogen. This
definition is now generally accepted, and thus the term " azo "
has obtained a definite signification.

The azo compounds are, as a rule, very easily prepared ; in
most cases, it is only necessary to add a solution of metallic
nitrite to an acid solution of a given amide, in order to obtain
the diazo compound of the radicle contained in the amide ;
thus, if I take a solution of aniline hydrochloride, and add to it
an equivalent quantity of sodium nitrite solution, the reaction
at once takes place, and the diazobenzene is produced ; it can
be readily separated from its solution, and obtained in the solid

66 THE BRITISH COAL-TAR INDUSTRY

state, one method being to add a solution of potassium dichromate,
when the chlorochromate of diazobenzene is produced. This
salt, when dry, is terribly explosive, and at one time was
suggested for use in warlike operations ; however, it very
rapidly decomposes when kept, losing nitrogen, and becoming
no longer efficient.

This explosiveness is readily understood when we consider
the constitution of the body which contains the group N=N .
It is manifestly in a state of unstable equilibrium, and a very
slight disturbance is sufficient to bring about its decomposition ;
and, for the same reason, you will at once see that its chemical
activity, as measured by its tendency to combine with other
bodies, will be great ; so that, if I add to it another molecule
of aniline salt, or, what amounts to the same thing, if I add to
two molecules of aniline only one of sodium nitrite, the
diazobenzene formed at once attacks the free aniline salt, and
what is known as diazoamidobenzene is formed, which, in the
presence of an aniline salt, becomes amidoazobenzene
C 6 H 5 N=NC 6 H 4 NH 2 . The oxalate of this body was once in
pretty general use as a yellow dye, but, as it happened to be
volatile at a very low temperature, it soon evaporated from the
dyed article, and was, therefore, discarded.

A compound having a very similar constitution and mode
of preparation has, however, long been in use, under the name
of " Bismarck brown," and is one of the most permanent of the
aniline colours. It is obtained as follows :

Metadinitrobenzene is prepared by boiling ordinary nitro-
benzene with nitric acid. The compound thus produced is
added cautiously, with constant agitation, to coarse iron borings,
kept boiling in a large quantity of water acidulated with hydro-
chloric acid. A violent reaction soon commences (I could readily
show you the experiment, but for the steam and unpleasant
odour produced) ; the four oxygen atoms contained in the
dinitrobenzene are replaced by hydrogen, thus :

4 C 6 H 4 (N0 2 ) 2 -h Fe 15 + 4 OH 2 = 4 C 6 H 4 (NH 2 ) 2 + S (Fe 3 O 4 ).

We have thus produced diamidobenzene, and this, when
purified from a little dissolved iron, is attacked with sodium
nitrite solution ; the reaction here is analogous to the one last
described, the final product of the reaction being a triamido-
azobenzene, the hydrochloride of which constitutes the well-

THE NEWER ARTIFICIAL COLOURING MATTERS 67

known colouring matter. We have thus two terms of a possible
series first, the amido-azobenzene (yellow, volatile, and fugitive),
and triamido-azobenzene (brown, and perfectly fast). Dr Witt
set himself the task of filling up the intermediate link, expecting
an orange colour, and a moderate stability for the diamido-
azobenzene he sought. In this he was not disappointed. A
study of the two compounds, from a purely scientific point of
view, led him to a perfectly accurate prediction ; and the
discovery of " chrysoidine," as the new colour was called, and
its production by the addition of diazobenzone chloride to a
solution of diamidobenzene was one of the first of a series of
researches which have, in various hands, enriched our science and
our dyers with a number of magnificent colours.

The further development of these colours commenced with
the introduction of a sulphonic group into one of the amido
compounds, the conversion of the sulphonic acid thus produced
into a diazo body, and then using it as before ; for instance, if
sulphanilic acid produced by the action of strong sulphuric acid
on aniline is converted into diazosulphanilic acid, and this added
to a solution of diamidobenzene-hydrochloride, the scarlet body
produced is the sulphonic acid of chrysoidine. Again, the same
body will act on resorcine to produce a colour only differing from
the last in that it contains hydroxyl instead of amido groups ;
this body has been used as a dye, under the name of tropaeoline
o. Witt also produced, by substituting diphenylamine for the
resorcine, or diamidobenzene, another beautiful orange, known
in commerce as tropaeoline oo. Other compounds were sub-
sequently prepared, and have obtained greater prominence ; these
were those in which a naphthol was substituted for the phenolic
or amido portion of the molecule, beautiful oranges being pro-
duced by the action of diazobenzene sulphonic acid on both a-
and /8-naphthol ; but these colours were much improved by the
introduction of sulphonic groups into both portions of the
molecule, a- or /3-naphthol-sulphonic acid being, in fact, substituted
for the naphthol only ; still, so far, the improvement was in the
direction of stability mainly, the shades still being yellow or
orange ; the red was yet to come.

Chemists will not be surprised to hear that the higher homo-
logues of benzene are found, when converted into amido com-
pounds, to give an increased redness of shade ; thus, with a given
phenol or amine, diazosulphotoluidinic acid, which differs from

68 THE BRITISH COAL-TAR INDUSTRY

diazosulphanilic acid by having an atom of hydrogen in the
benzene ring replaced by methyl, gives redder shades than does
the latter, while the substitution of another hydrogen in the same
way, as is the case with the diazo compound derived from
sulphoxylidinic acid, produces a scarlet. Messrs Meister,
Lucius & Brtining were among the first to produce a scarlet
by this method, but they also introduced both the sulpho
groups into one side of the molecule that of the naphthol. In
their patent they describe the preparation of two isomeric /3-
naphthol-disulphonic acids, the sodium salts of which are
differently soluble in alcohol, the most insoluble one giving a
redder colour than the other. On one or other of these they act
with diazoxylene chloride, produced by the action of a nitrite on
xylidine chloride. The most insoluble salt above mentioned gives
a scarlet closely approaching cochineal scarlet, and perfectly fast.

Mr R. Meldola has also taken out a patent for a scarlet,
in which no less than three sulpho groups are engaged. He
prepares diazosulphoxylidinic acid, and with this acts on /3-
naphthol-disulphonic acid ; on the addition of ammonia, the
colour is immediately thrown down, as you perceive. This is,
after a slight purification, ready for use. By certain modifications,
a scarlet, closely approaching the scarlet obtained by dyeing
cochineal in the presence of oxychloride of tin, is produced.

So far, we have only oranges and scarlets by these reactions.
Whether other colours can be similarly produced remains to be
seen ; but 1 may mention that Mr Meldola has recently com-
municated a paper to the Berlin Chemical Society, in which he
describes a violet colour unfortunately not a dye obtained
in a somewhat similar way. If we act on dimethylaniline the
body from which the violets described in the first part of my
lecture are derived with a nitrate, not an azo but a nitroso-
dimethylaniline is produced, thus : C 6 H 4 NON(CH 3 ) 2 . This
body is as ready to combine with others as an azo body is, and
does so in a very similar way, the oxygen atom being elimin-
ated in the process, so that if we act with it on /3-naphthol the
following combination takes place 1 :

C 6 H 4 .N.N(CH 3 ) 2
/3C 10 H 5 OH,

1 This formula is given under reserve, as a complete investigation of the
compound has not yet been published.

THE NEWER ARTIFICIAL COLOURING MATTERS 69

the oxygen of the nitroso group going off with two hydrogens
from the /3-naphthol, the place of which is taken by a group,
which is equivalent to azo-dimethylaniline. The colour crys-
tallises magnificently, but its dyeing powers are very feeble.

DISCUSSION

Mr SPILLER said it would be manifest that the benzene dye
industry had of late years made gigantic strides. When he
first became connected with the industry it was the rule to
select out the benzole of the coal-tar and throw away a large
residual product known as dead-oil. But the requirements of
the latest forms of colouring matter which had been mentioned,
particularly the orange and scarlet, demanded that the dead-oil
should be worked up with a view to extract from it the toluene
and xylene. Naphthalene had for a great number of years been a
perfect bugbear in scientific industry. It was produced in immense
quantities in the manufacture of gas, and, whilst by the labours
of Perkin and Graebe anthracene had been employed in the
manufacture of alizarin, the naphthalene had been thrown away.
It was, however, now required for the manufacture of the
scarlet described by Mr Friswell.

Dr H. E. ARMSTRONG said the paper ought to convey a
sound lesson to the objectors to abstract science, because practi-
cally speaking the whole of these colours were the result of
investigations originally undertaken without any practical aim.
There was a large amount of material still remaining in coal-tar
not utilised, and there was no doubt a great future in that
direction.

It was not more than ten or twelve years ago that it was
found that alizarin could be produced artificially, and now
practically all the Turkey-red used was produced artificially.
A few years ago the diazo compounds were substances which
even chemists were almost afraid to handle. They were discovered
by Dr P. Griess, and were extremely unstable and difficult to
manipulate, and it would have appeared almost laughable that
such compounds would be used for producing colouring matters
on a large scale. Dr O. Witt's theoretical views with regard
to the constitution of colouring matters had been very productive,
and frequently enabled chemists to say, not only that a certain
body would be a colouring body, but would have a certain shade.

yo THE BRITISH COAL-TAR INDUSTRY

Mr R. MELDOLA said there was no doubt that a great many
of the products that now ran down our drains would one day
become quite as valuable as many of those which were at present
employed in factories. New diazo compounds of more and more
complex constitutions were being discovered continually, and their
number might increase indefinitely.

The Chairman (Prof. CHARLES GRAHAM) said that when it was
remembered that Faraday discovered benzene before any of them
were born, and that Unverdorben discovered aniline long ago,
it was evident that there must have been much pure scientific
research carried on before manufacturers were able to make use
of it and convert the products of coal-tar distillation into the
valuable dyeing materials we now possess.

V.: i88i

INDIGO AND ITS ARTIFICIAL PRODUCTION

BY PROFESSOR H. E. ROSCOE, LL.D., F.R.S.
(Discourse delivered at the Royal Institution, 2yth May 1881)

THE first portion of this address deals with the various syntheses
of indigotin up to the commercial introduction of ortho-nitro-phenyl
propiolic acid in 1881, and with the mode of application of that body.

Professor Roscoe proceeds as follows :

The potential importance, from a purely commercial point of
view, of the manufacture of synthetic indigo may be judged of
by reference to the following statistics, showing that the annual
value of the world's growth of indigo is no less than four millions
sterling.

ESTIMATED YEARLY AVERAGE OF THE PRODUCTION OF INDIGO IN THE
WORLD, TAKEN FROM THE TOTAL CROP FOR A PERIOD OF TEN YEARS

Pounds
weight.

Pounds
sterling.

Bengal, Tirhoot, Benares, and N.W. India
Madras and Kurpah
Manilla, Java, Bombay, etc. ....
Central America ......
China and elsewhere, consumed in the country

8,000,000
2,200,000

2,250,000

2,000,000
400,000
500,000
600,000
say 500,000

4,000,000

How far the artificial will drive out the natural colouring
matter from the market cannot, as has been said, be foreseen.
It is interesting, as the only instance of the kind on record, to

72 THE BRITISH COAL-TAR INDUSTRY

cast a glance at the history of the production of the first of the
artificial vegetable colouring matters, alizarin. In this case the
increase in the quantity produced since its discovery in 1869
has been enormous, such indeed that the artificial colour has
now entirely superseded the natural one, to the almost complete
annihilation of the growth of madder-root. It appears that
whilst for the ten years immediately preceding 1869 the aver-
age value of the annual imports of madder-root was over one
million sterling, the imports of the same material during last
year (1880) amounted only to 24,000; the whole difference
being made up by the introduction of artificial alizarin. In
1868, no less a quantity than 60,000 tons of madder-root were
sent into the market, this containing 600,000 kilos of pure
natural alizarin. But ten years later a quantity of artificial
alizarin more than equal to the above amount was sent out
from the various chemical factories. So that in ten years the
artificial production had overtaken the natural growth, and the
300,000 or 400,000 acres of land which had hitherto been used
for the growth of madder can henceforward be better employed
in growing corn or other articles of food. According to returns,
for which the speaker had to thank Mr Perkin, the estimated
growth of madder in the world previous to 1869 was 90,000
tons, of the average value of 45 per ton, representing a total
of 4,050,000.

Last year (1880) the estimated production of the artificial
colouring matter was 14,000 tons, but this contains only 10
per cent, of pure alizarin. Reckoning i ton of the artificial
colouring matter as equal to 9 tons of madder, the whole
artificial product is equivalent to 126,000 tons of madder. The
present value of these 14,000 tons of alizarin paste, at 122
per ton, is 1,568,000. That of 126,000 tons of madder at
45 is 5,670,000, or a saving is effected by the use of
alizarin of considerably over four millions sterling. In other
words, we get our alizarin dyeing done now for less than
one-third of the price which we had to pay to have it done
with madder.

Our knowledge concerning the chemistry of alizarin has also
proportionately increased since the above date. For whilst at
that time only one distinct body having the above composition
was known, we are now acquainted with no less than nine out of
the ten di-oxyanthraquinones the existence of which is theoreti-

INDIGO AND ITS ARTIFICIAL PRODUCTION 73

cally possible, according as the positions of the two molecules of
hydroxyl are changed.

-co-

co-

Of the nine known di-oxyanthraquinones, only one, viz.
alizarin, or that in which the hydroxyls are contained in the
position i, 2, is actually used as a colouring agent. Then again,
three tri-oxyanthraquinones, C 14 H 5 O 2 (OH) 3 , are known. One
of these is contained in madder-root, and has long been known
as purpurin. The other tri-oxyanthraquinones can be artificially
prepared. One termed anthrapurpurin is an important colour-
ing matter, especially valuable to Turkey-red dyers, as giving a
full or fiery red. The other, called flavopurpurin, gives an
orange dye with alumina mordants. All these various colouring
matters can now be artificially produced, and by mixing these in
varying proportions a far greater variety of tints can be obtained
than was possible with madder alone, and thus the power of
diversifying the colour at will is placed in the hands of the dyer
and calico-printer.

It is quite possible that in an analogous way a variety of
shades of blue may be ultimately obtained from substituted
indigos, and thus our catalogue of coal-tar colours may be still
further increased.

To Englishmen it is a somewhat mortifying reflection, that
whilst the raw materials from which all these coal-tar colours
are made are produced in our country, the finished and valuable
colours are nearly all manufactured in Germany. The crude
and inexpensive materials are, therefore, exported by us abroad,
to be converted into colours having many hundred times the
value, and these expensive colours have again to be bought by
English dyers and calico-printers for use in our staple industries.
The total annual value of manufactured coal-tar colours amounts
to about three and a half millions ; and as England herself,
though furnishing all the raw material, makes only a small
fraction of this quantity, but uses a large fraction, it is clear
that she loses the profit on the manufacture. The causes of

74 THE BRITISH COAL-TAR INDUSTRY

this fact, which we must acknowledge, viz. that Germany has
driven England out of the field in this important branch of
chemical manufacture, are probably various. In the first place,
there is no doubt that much of the German success is due to
the long-continued attention which their numerous universities
have paid to the cultivation of organic chemistry as a pure
science. For this is carried out with a degree of completeness,
and to an extent, to which we in England are as yet strangers.
Secondly, much again is to be attributed to the far more general
recognition amongst German than amongst English men of
business of the value, from a merely mercantile point of view, of
high scientific training. In proof of this it may be mentioned, that
each of two of the largest German colour-works employs no less a
number than from twenty-five to thirty highly educated scientific
chemists, at salaries varying from 250 to ^500 or j6oo per
annum. A third cause which doubtless exerts a great influence
in this matter is the English law of patents. This, in the special
case of colouring matters at least, offers no protection to English
patentees against foreign infringement, for when these colours
are once on the goods they cannot be identified. Foreign
infringers can thus lower the price so that only the patentee,
if skilful, can compete against them, and no English licensees
of the patent can exist. This may to some extent account for
the reluctance which English capitalists feel in embarking in
the manufacture of artificial colouring matters. That England
possesses both in the scientific and in the practical direction
ability equal to the occasion, none can doubt. But be that as
it may, the whole honour of the discovery of artificial indigo
belongs to Germany and to the distinguished chemist Professor
Adolf Baeyer, whilst towards the solution of the difficult problem
of its economic manufacture the first successful steps have been
taken by Dr Caro and the Baden Aniline and Soda Works of
Mannheim.

VI. : 1885

THE COLOURING MATTERS PRODUCED
FROM COAL-TAR

BY W. H. PERKIN, F.R.S.

(Presidential Address, Society of Chemical Industry, 1885 :
Jour. Soc. Chem. Ind., 1885, p. 426)

TAKING a precedent from some of those who have occupied
this chair before me, I have selected for my few remarks to-day
the subject in relation to Technical Chemistry, with which I have
been personally connected namely, the colouring matters pro-
duced from coal-tar products, with some of the lessons its
development appears to me to teach us in connection with
industrial chemistry. Sir Frederick Abel, in his address in 1883,
when speaking of the history of gunpowder, said that " It is one
of the most remarkable features connected with the history of
gunpowder, that until the last quarter of a century no radical
changes should have been introduced into the manufacture and
modes of applying this, the first known practically useful
explosive agent." It appears to me that this is more or less
true of all the older industries, which resulted simply from
experiment and observation without any other basis to work
from. They have had long histories in which little progress has
been made, but of late years, owing to our advanced and rapidly
increasing scientific knowledge, they are undergoing great, and
in many cases radical, changes.

The coal-tar colour industry stands in a very different position
to our older ones. It has a sharply defined origin, and a very
short history dating back only to 1856, and it is not yet twenty-nine
years since the date of the first patent. It is an industry which has
been founded on scientific discovery, and has developed side by
side with it, being in fact a most important handmaid to research,

76 THE BRITISH COAL-TAR INDUSTRY

which in its turn has repaid it by new discoveries. At the date
of its introduction very little was known of the chemistry of
colouring matters ; they were always found difficult bodies to
investigate, and when produced in reactions were generally
regarded as secondary products, and every endeavour was made
to get rid of them so that the other products associated with them
might be examined ; but now, owing to the very extended study
which has been made of these bodies, on account of this industry,
and the relationships which have been found to exist between the
colour of the compounds and the chemical constitution, it is
possible with more or less certainty to predict the colour a com-
pound will have before it is produced, and the means which can
be used to modify it.

It will be possible for me to give you only a very brief sketch
of the history of this industry in the time at my disposal ; any-
thing like a complete account would fill volumes. On account
of this I shall not be able to refer except casually to the coal-
tar industry itself, the development of which is mainly due
to the one under consideration. Nor can I give a consecutive
account of the coal-tar colours themselves, because the discovery
of new series of colouring matters, and the progress of old ones,
necessarily produce overlapping as it were, and renders such a
course difficult and confusing. I therefore propose to take them
according to the groups we now know them to belong to. I will
therefore commence with that which contains the first colouring
matter connected with this industry i.e. the mauveine and
safranine group of compounds.

As I already mentioned, the coal-tar colour industry dates
from 1856, the discovery of the aniline purple or mauve dye
being made during the Easter vacation of that year, and the
patent for its production taken out on the 26th of the following
August. I have already described elsewhere * how the discovery
of this colouring matter was made during the prosecution of
scientific research which had for its object the artificial production
of quinine, a subject which of late has very much occupied the
attention of chemists, though it has not as yet been accomplished.

When commencing this industry, which was looked upon by
many with considerable doubt as to its practicability, the diffi-
culties encountered were very numerous on account of its unique
character, but few of the processes having their representatives

1 See p. 5, ante.

COLOURING MATTERS FROM COAL-TAR 77

in other industries ; the products were also very valuable, so that
great care had to be employed with them. Moreover, the success
of the product tinctorially had not been proved on the large scale,
so that it was necessary to proceed tentatively and not launch out
too rapidly.

Aniline, as is well known, was at this period a rare body,
originally obtained from indigo by Unverdorben in 1826 ; for
its production from benzene we are first indebted to the discovery
of nitrobenzene in 1834 by Mitscherlich, and then to Zinin, who
found that this substance when submitted to certain reducing
agents produced a base which was eventually identified as aniline.
It was not long before the date of this industry that a method
of producing this base from nitrobenzene, with greater ease than
by the process of Zinin, was discovered ; and it is to Bechamp
we are indebted for this, who found that the reduction might be
easily accomplished by means of iron filings and acetic acid. Had
this discovery not been made, aniline could not have been pro-
duced sufficiently cheap to be used for the production of colour-
ing matters. And it is interesting to note that this process of
Bechamp, slightly modified, is the one used to-day for the pro-
duction not only of this base, but its homologues and analogous
compounds.

It was not long before the difficulties of producing nitro-
benzene were to a great extent overcome. Messrs Simpson,
Maule & Nicholson also began to experiment on the production
of nitrobenzene, and after a time were able to produce it at a
sufficiently low cost to be able to supply us with part of our
requirements. I mention this in passing because it was the
starting-point of the history of the connection of this firm with
artificial production of colouring matter, which they carried on
so successfully afterwards.

After the mauve was discovered it was necessary to teach
dyers how to use it. Being an organic base, it is opposite in
properties to the vegetable colouring matter, and therefore the
ordinary methods of application were not generally useful, and
much time had to be spent in dye-houses and print-works in the
early days of this product in reference to this subject, and at that
time the question of fastness to light, soap, and bleaching liquor
was much insisted on. Fortunately for the future of the coal-tar
colour industry, although the mauve would not resist bleaching
liquor well, it proved to be a very fast colour the fastest purple

7 8 THE BRITISH COAL-TAR INDUSTRY

yet produced, I believe and thus its introduction became rapid.
After this the love of brilliancy of colour which it had induced
caused less attention to be given to the subject of fastness. I
quite think that had this, the first coal-tar colouring matter,
yielded colours as fugitive as some which have since been used,
this industry would probably have been, to say the least, much
delayed in its progress ; so that it will be seen the mauve had to
bear all the burdens of the difficulties incident on the inauguration
of this industry, the future products being free from these
impediments. The importance of this colouring matter after its
success was established was quickly recognised in France, and its
manufacture commenced there. This soon resulted in its importa-
tion into this country irrespective of patent rights. As, however,
the foreign manufacturer employed responsible agents in this
country, the law was without difficulty put into operation success-
fully unfortunately, however, only to teach Continental manu-
facturers the lesson not to employ responsible agents in this
country any longer, but, by means of correspondence or travellers
to deal directly with the consumers, and this modus operandi
(practically, though perhaps not theoretically) enabled them to
ignore the existence of patents, and import their products freely
into this country. On this point I shall have to speak again
further on. The mauve was first employed in silk dyeing in
London, Messrs Thomas Keith & Sons, of Bethnal Green, being
the first to use it. The second application was calico printing,
Messrs James Black & Co., of Glasgow, being the first to
employ it largely for this purpose. It afterwards was extended
to other trades.

With reference to the chemical history of this dye, although
it had been submitted to analysis very soon after its discovery,
its formula, or rather the formula of its principal constituent
" mauveine," was not established until some time after it had
become a commercial product, and was prepared in a crystalline
condition. It was then shown to have the composition C 27 H 24 N 4
(Proc. R.S.y xiii. 170).

It was found to be a very powerful base, decomposing
ammonia salts with evolution of ammonia, and combining with
carbonic acid to form a carbonate. Its ordinary salts are pro-
duced by its combination with one molecule of a monobasic
acid, its hydrochloride having the formula C 2 7H 2 4N 4 HC1.

In concentrated sulphuric acid mauveine dissolves with a dirty

COLOURING MATTERS FROM COAL-TAR 79

green colour, changing to blue on slight dilution, and back to
purple when thoroughly diluted ; this is a distinctive reaction of
this class of colouring matters. Further researches have shown
(Jour. Chem. Soc., xxxv. 717732) that in the ordinary commercial
product, besides mauveine, there are two other compounds, one
possessing a redder shade of colour, the other being remarkable
for its great solubility in alcohol. This latter from analysis
appears to have the formula C^H^N^

The first product, or mauveine, is evidently a derivative of
paratoluidine and aniline. The second of orthotoluidine and
aniline, and the third of pure aniline. This has been called
pseudo-mauveine. It might perhaps be better called pheno-
mauveine.

When boiled with aniline mauveine yields an indigo-blue
product, difficultly soluble in alcohol. This change takes place
without formation of ammonia, and shows how different
mauveine is in its character to rosaniline.

Runge found that aniline, when treated with dilute chloride
of lime, yielded a blue- or violet-coloured solution, which soon
underwent change. Some experiments on this, made in 1868
(Jour. Chem. Soc., xxii. 25-27), showed that the product which I
named " Runge's blue" was a peculiar compound, the salt of
an organic base, which itself dissolved in alcohol with a reddish-
brown colour, the salts being blue. It is quite different from
mauveine, and of no practical value ; but what is interesting is
that when exposed to heat, as by boiling a solution of one of
its salts, it decomposes with formation of mauveine.

A beautiful colouring matter was obtained from mauveine
by treating it with ethyl iodide. It gives shades of colour of
a very red purple tint, and it was therefore called dahlia. It
was mostly used in calico delaine and other kinds of printing,
but being costly, the production was never very large. This
substance is a monoethyl derivative of mauveine, and all
attempts to further ethylate this compound have proved fruitless.
In properties it appears to be more like an ammonium compound
than a displacement product.

SAFRANINES

In the preparation of mauveine, a colouring matter was
obtained from the liquors, from which it was precipitated,

8o THE BRITISH COAL-TAR INDUSTRY

yielding beautiful crimson-red shades of colour on silk. The
amount produced in this was so small, however, that we were not
able to introduce it as a dye. But it was found that it could be
produced by the oxidation of the mauve dye itself, and was
then manufactured under the name of "aniline pink," but
afterwards " safranine." This substance is evidently closely
related to mauveine, as it gives the characteristic reaction with
sulphuric acid I have already referred to.

The preparation of this from the mauve dye was too costly
to allow of its being brought into general use. However, new
processes have been since discovered, by which this and other
colouring matters of its class can be produced cheaply.

The first of these processes consisted in passing nitrous acid
into commercial aniline, heating the mixture with arsenic acid,
and then extracting the colouring matter produced. Hofmann
examined this, and showed that it had the formula C 2 iH 2 oN 4
(Ber., vi. 526, 1872).

By examination of the product which was obtained by
oxidising the mauve dye I found it to have the composition
C2oH 18 N 4 (Jour. Chem. Soc., xxxv. 731), results which correspond
with analyses published by Dale and Schorlemmer (Jour. Chem. Soc.,
xxxv. 682) obtained from the examination of a similar product.
This substance, I also found, was associated with that examined
by Hofmann in a product prepared by Messrs Guinon & Co.,
of Lyons.

Methods of a more synthetical nature have since then been
discovered. O. Witt found that safranine could be obtained from
orthoazotoluene and hydrochloride of toluidine at i5O-2oo C.
(Bcr., x. 874, 1877). He then found that by oxidising a
mixture of one part of paraphenylenediamine, and two parts of
aniline, on the application of heat a safranine could be obtained
which has the formula C 18 H 16 N 4 , and which is called pheno-
safranine.

The formation of this colouring matter by this and other
processes has been studied by Nietzki (Ber., xvi. 464). He
finds that the aniline in the reaction, in which paraphenylenedia-
mine takes part, may be substituted by other primary monamines,
or a mixture of these with dimethylaniline, and thus a large
number of these dyes can be obtained.

Phenosafranine is now produced very largely, and in a pure
crystallised condition, and is a very useful dyeing agent.

COLOURING MATTERS FROM COAL-TAR 81

If we assume that all the safranines are strictly homologous
compounds, the formula that Nietzki gives for phenosafranine
would make the formula of that examined by Hofmann, and
that examined by myself and Dale and Schorlemmer, to be
incorrect, and that they should contain two hydrogens more
than are assigned to them. This I cannot think is possible from
all the analytical results we obtained.

The constitution of mauveine has not yet been established,
and I have still experiments on this subject in hand. This may
also be said of safranine, I think, although Nietzki has proposed
a formula for it in which nitrogen occupies a similar position
to the methane-carbon in the rosaniline series.

TRIPHENYLMETHANE DERIVATIVES

We must now go back again to the early days of this
industry to consider the next class of compounds viz.
triphenylmethane derivatives.

The industrial success of the mauve dye caused aniline to
become a very favourite body to experiment with, and the result
was that in 1859 the discovery of that important colouring
matter first known as fuchsine or magenta took place. Hofmann
had observed in his experiments on the action of carbon tetra-
chloride on aniline in 1858 the formation of a red colouring
matter, which consisted of this substance as a secondary product
of the reaction, but it was M. Verguin who first discovered a
process for the transformation of aniline into a red colouring
matter of tinctorial value. The discovery of this compound
marks a most important fresh departure in the history of coal-
tar colours. As I mentioned, the mauve had paved the way
for future colouring matters, and this new substance, which could
be applied to fabrics by the same methods as the mauve, was
most eagerly sought after owing to the brilliancy of its colour,
and probably its manufacture was one of the most successful
financially of all the aniline colours.

M. Verguin's process, which consisted in treating commercial
aniline with tin tetrachloride, was soon superseded by better
processes. The number of patents taken out for the production
of this dye was very large, and all imaginable products were
claimed as capable of producing it from aniline. The two most
important, however, were those in which mercury nitrate and

82 THE BRITISH COAL-TAR INDUSTRY

arsenic acid were used. The first of these processes, with which
I had some experience, required much care to regulate the
reaction and prevent deflagration. The next process with
arsenic acid, known as Medlock's, was by far the best, and was
employed very extensively until the last few years, nitrobenzene
being now mostly used as the oxidising agent in the place of
arsenic acid.

The manufacture of magenta, which at this period was often
called roseine, was carried on chiefly in this country by Messrs
Simpson, Maule & Nicholson, by the arsenic acid process.
Mr E. C. Nicholson and Dr A. P. Price, of this firm, worked
out the process with great success, and were the first to produce
this colouring matter in a pure state. The beautiful display
of the crystallised acetate, shown at the Exhibition of 1862,
illustrated this fully.

It was with products supplied by Mr Nicholson that Dr
Hofmann made his first researches on this colouring matter.
He changed its name from roseine to rosaniline, and found that
the base, when in combination with acids, had the formula
QoHjgNs.

The important observation of Nicholson, and the critical
experiments of Hofmann, on the necessity of using, not pure
aniline, but a mixture of aniline and toluidine for the production
of this substance, was made about this period. 1

The next important step in this industry was the use of
rosaniline itself as a source of new colouring matters. For
this we are indebted to the experiments of two French chemists,
viz. MM. Girard and De Laire, who discovered that rosaniline
salts, when heated with aniline, gave violet and blue colouring
matters, which they called violet imperial and bleu de Lyon. It
is, however, to Mr Nicholson that the credit of producing
these bodies, in a practically pure state, belongs. This especially
refers to the blue, the product known as opal blue, used by
Dr Hofmann in his investigations on the subject, being of great
purity. Dr Hofmann showed that these products were phenyl-
ated rosanilines, as is now well known, ammonia being given off

1 In my original patent it was shown that colouring matters could be
obtained not only from aniline, but also from toluidine, xylidine, and
cumidine these bases, as usually prepared at that date from the hydro-
carbons obtained by fractioning coal-tar naphtha, not being pure, but
mixtures.

COLOURING MATTERS FROM COAL-TAR 83

in the reaction. And I may mention in passing that the manu-
facture of these blues is now carried on to such a large extent
that the ammonia produced in this reaction is collected for the
production of its sulphate or other salt.

One of the difficulties in the way of the new blue was its
insolubility in water. Mr Nicholson, however (in 1862),
probably thinking of the method used to render indigo soluble,
experimented upon the action of sulphuric acid on this com-
pound, and he found that it was possible to obtain sulphonic
acids from it. One of these, the sodium salt of which is
known as Nicholson's or alkali blue, is the monosulphonic acid,
which is itself insoluble in water, but forms soluble salts, which
can be applied to the goods, and then decomposed by acids.
This compound has had much to do with the successful intro-
duction of this colouring matter. The other product known as
soluble blue is the sodium salt of the trisulphonic acid.

In the early part of 1864 the Hofmann violets were intro-
duced. These, as is well known, are the ethylated rosanilines
produced by acting upon rosaniline with ethyliodide. These
colouring matters are more brilliant, though much more fugi-
tive than mauveine ; but by this time the desire for per-
manency was giving way very much to that of brilliancy ; and
these colouring matters were quickly taken up by dyers and
calico printers.

About this time some colouring matters derived from phenol
were introduced, and which, curiously, are found to belong to
the class of substances now under consideration. These were
brought forward by Messrs Guinon, Marnas & Bonnet, of
Lyons. The first product was aurin, prepared from phenol by
means of oxalic and sulphuric acid (Kolbe and Schmitt's process).
The next was peonine, obtained by acting upon aurin with
ammonia. The third was azuline, prepared by heating aurin
with aniline. This last was a blue dye, which has since been
shown to consist chiefly of triphenylrosaniline.

Purple and violet derivatives were also obtained from
rosaniline by a process of my own, in which brominated
turpentine was employed. These were known as Britannia
violets, and were much used.

Other coloured derivatives were also discovered ; for example,
by the action of aldehyde and sulphuric acid, a blue product
was obtained, which, when treated with sodium hyposulphite

84 THE BRITISH COAL-TAR INDUSTRY

or sulphuretted hydrogen water, yielded the well-known aldehyde
green.

On examining the action of acetylchloride on Britannia violet,
I obtained a peculiar green, which was used principally by calico
printers, and very considerable quantities of acetylchloride were
prepared for this purpose. The process was not published.
This green was of a blue shade, and was obtained in a crystallised
condition in combination with picric acid. The crystals had a
golden metallic reflection.

Soon after this it was noticed that a green compound was
produced in the preparation of the Hofmann violets, though
generally only in small quantities. It was afterwards found that
by making rosaniline react with an excess of methyl iodide
it could be produced practically. It was called iodine green ;
but the product now manufactured is a chloride. This colour-
ing matter gave good candlelight greens. One of its peculiarities
is that when heated it is converted into violet methylrosaniline,
with loss of methylchloride.

A new method of producing rosaniline violet was proposed
by Lauth, and patented by MM. Porrier & Chappat, in June
1866. The process consisted in taking aniline, in which
hydrogen had been replaced by an alcohol radical, and oxidising
this instead of first preparing rosaniline, and then replacing the
hydrogen in the colouring matter by the radical. The product
proposed for this purpose was methylaniline.

Owing to the improved method of methylating aniline,
which, I believe, was first proposed by Messrs Girard and
De Laire (Bull. Chem. Soc. [2], vii. 360), this process has become
a very important one, and large quantities of dimethylaniline
are now used, the oxidation being effected by copper salts. The
product, according to the researches of Otto Fischer, consists
chiefly of pentamethylpararosaniline.

The most important advance in the production of green
colouring matters of the triphenylmethane series was the dis-
covery of the benzaldehyde, Victoria, or malachite green.

In 1877, Otto Fischer, whilst investigating the condensation
products of tertiary aromatic bases (Eer.^ x. 1625), obtained by
the action of benzaldehyde on dimethylaniline in presence of
chloride of zinc, a colourless base of the formula C23H 26 N 2 , the
salts of which, when exposed to the air, rapidly oxidised to a
fine blue-green dyestuff, which, he thought, would prove to be

COLOURING MATTERS FROM COAL-TAR 85

of complicated constitution. A little later (Ber. y xi. 950) he
showed that by treating this colourless base with some of the
ordinary oxidising agents, this green could be more easily
produced, and that it stood to the colourless compound in the
same relation as rosaniline does to leucaniline. Emil and Otto
Fischer afterwards said (Ber., xii. 796) that the first experiments
for the production of this green were made by the Badische
Anilin- und Soda-Fabrik, in March 1878. About this time
Oscar Doebner (Eer.^ xi. 950) found that a green colouring
matter was produced by heating benzaldehyde with benzoyltri-
chloride and zinc chloride. This product has been found to be
identical with that of Fischer's. This green colouring matter
is now largely made from benzaldehyde, as this process is found
to be the best. A similar compound is also prepared from
diethylaniline, and is known as brilliant green. It is a beauti-
fully crystalline body. It is rather curious that this produces
shades of colour somewhat yellower than the green from
dimethylaniline, whereas, being of a higher molecular weight,
we should have expected it to be bluer.

The principal difficulty which had to be contended with in
the production of these colouring matters was the need of a
supply of benzaldehyde. The usual method of obtaining it
from bitter almonds, which was the only one in use, was quite
out of the question, so that other sources had to be looked for.
The Badische Anilin- und Soda-Fabrik, however, successfully
overcame this difficulty. At first they experimented with the
process of Lauth and Grimaux, which consists in the oxidation
of benzylchloride, with an aqueous solution of lead nitrate ; the
product made by this process, however, was too dear. But they
found that the decomposition of benzylidenedichloride, by means
of water, as observed by Cahours (Ann. Chem. SuppL, ii. 306) and
Limpricht (Ann. Chem., 139, 316), gave them a means of produc-
ing this compound practically, the reaction being as follows :

C 6 H 5 CHC1 2 + OH 2 = C 6 H 5 .CHO + 2HC1.

This process, which they have successfully employed since
March 1878, consists in the preparation of benzylidenedichloride
from pure toluene, and in the subsequent treatment of this
chlorinated body with milk of lime, at 100 C.

I have stated that the group of colouring matters under
consideration are called triphenylmethane derivatives, and to

86 THE BRITISH COAL-TAR INDUSTRY

show how this has been proved to be the case, I must now refer
very briefly to some of the theoretical work which has led to
this knowledge. The most important of this refers to rosaniline.
I have already drawn attention to the work of Hofmann, which
gave us the first knowledge of the composition of this colouring
matter, and the further information that it contained hydrogen,
which could be displaced by phenyl and alcohol radicals ; but
as to the matter of constitution, I think the experiments of
Caro and Wanklyn were the first, as they showed the relation
which existed between rosaniline and aurin, or rosolic acid, and,
in fact, they produced rosolic acid from rosaniline ; but it is to
the beautiful researches of Emil and Otto Fischer that we are
indebted for a clear knowledge of the constitution of this class
of colouring matter.

But to clear the ground before proceeding further, I must
remind you that ordinary commercial rosaniline, or magenta,
prepared from aniline and toluidines, is a mixture of colouring
matters. This was first known to Mr Nicholson, who found
that for the production of the finest blues it was necessary to
purify the base and separate one of these before phenylating ;
but it is only of later years that the difference between these
bodies has been carefully studied and explained. The base
examined by Hofmann contained C 2 o, and is the chief constituent
of commercial rosaniline. The other contains C 19 , and is now
called pararosaniline, because it is produced from aniline and
paratoluidine. Similarly, in commercial aurin, two compounds
are found, one containing C^, now called rosolic acid, and one
containing C 19 , now called aurin ; and these latter can be pro-
duced from the corresponding rosanilines ; and Dale and Schor-
lemmer have shown that aurin can be also converted into para-
rosaniline by the action of ammonia (Jour. Chem. Soc.,
xxxii. 121).

Emil and Otto Fischer, however, by submitting the leuco
compound of commercial rosaniline to the diazo reaction,
obtained the hydrocarbon C 20 H 18 , and from rosaniline prepared
from paratoluidine and aniline the hydrocarbon C 19 H 16 .

And this latter hydrocarbon was found to be identical with
Kekule's triphenylmethane

COLOURING MATTERS FROM COAL-TAR 87

On nitrating this hydrocarbon, they obtained a trinitro
derivative, which, when reduced, gave the triamido body,

NH 2 C 6 H 4 , xC 6 H 4 NH 2
[/ ^H

NH 2 C 6 H,

which is paraleucaniline, and by carefully heating its hydro-
chloride to 1 50- 1 60 C., it was converted into pararosaniline.

Also they found that by oxidising trinitrotriphenylmethane
they obtained trinitrotriphenylcarbinol, and this when reduced
gave pararosaniline direct.

From these results the constitution of the base is evidently

NH 2 C 6 H 4V yC 6 H 4 NH 2

NH 2 C 6 H

Pararosaniline

the salts the hydrochloride, for example being

NH 2 C C H 4V /C 6 H 4 NH.HC1
>C I

NH 2 C 6 1

Pararosaniline hydrochloride.

Similar results were obtained from the hydrocarbon from
rosaniline ; it is tolyldiphenylmethane :

The rosolic acid and aurin corresponding to the rosanilines
are constituted in an analogous manner :

HOC 6 H 4 \ /C 6 H 4 O HOC 6 H 3 (CH 3 )v /C 6 H 4 O

>C_ _J and >C I

HOCH/ HOC,

'6 J
Aurin. Rosolic acid.

From these results we see the beautiful relationships of the
various colouring matters of this series to each other, and by it
obtain information which is of practical value;, as well as
theoretical. The following formulae of a few of these products
further illustrate this :

H \ / H

Methane (Marsh Gas) >C<

H/ X H

88 THE BRITISH COAL-TAR INDUSTRY

Triphenylmethane

C 1

H 2 NC 6 H 4 v /C 6 H 4 NH 2

n 2 ^e n 4\ /^

Leucopararosaniline /C\

H 2 NC 6 H/ \H

H 2 NC 6 H 4 v ,C 6 H 4 NH 2
Pararosaniline /C\

H 2 NC 6 H/ X OH

.,. H 2 NC 6 H 4V /C 6 H 4 NH.HC1

Pararosaniline 2 \r/ I

hydrochloride H 2 NC 6 H 4 <

L 2

Triphenylpara-

rosaniline
hydrochloride
(Aniline Blue)

H(C 6 H 5 )NC 6 H 4V /C 6 H 4 N(C 6 H 5 )H
H(C 6 H 5 )NC 6 H 4 <

Hexamethylpara- | (CH 3 ) 2 NC 6 H 4 s v ^ xC 6 H 4 N(CH 3 ) 2 Cl

rosaniline > /^ '

(Methyl Violet) ) (CH 3 ) 2 NC 6 H/

(CH 3 ) 2 NC 6 H 4X / C 6 H 4 N(CH 3 ) 2 C1

Methyl Green >C^- '

C1(CH 8 ) 3 NC 6 H/

Benzaldehyde (CH 3 ) 2 NC 6 H 4V / C 6 H 4 N(CH 3 ) 2 C1

or j>C^- '

Victoria Green QH/

(C 2 H 5 ) 5 NC 6 H 4V / C 6 H 4 N(C 2 H 5 ) 2 C1

Brilliant Green >C^- '

r TT /

^6^6

NaSO 3 ) r w r w / NaSO 3

H(C 6 H 5 )N f C 6W 3 \ Utl 3 1 N(C6 H 5 )

Soluble Blue ^-

NaS0 3

The effect of displacing hydrogen by hydrocarbon radicals in
rosaniline is seen to result in the shade of colour becoming bluer
for each hydrogen displaced the effect of those of high molecular
weight, such as phenyl, being to produce the greatest change ;
thus triphenylrosaniline is blue, whilst hexamethylrosaniline is
blue violet, notwithstanding it contains six hydrogens displaced.

After all the displacements possible have been effected, as
in hexamethylrosaniline, the result of the combination of the

COLOURING MATTERS FROM COAL-TAR 89

products with halogen compounds of methyl is very interesting.
The particular group to which this is attached becomes of the
nature of an ammonium group, and the colour does not become
bluer, but changes to green i.e. methyl green, and this, like
other ammonium compounds, when heated, dissociates with loss
of the halogen compound of methyl, and then hexamethylros-
aniline is reproduced. Again, if this ammonium group be sub-
stituted by phenyl, we also get a green product i.e. Victoria
green.

The structure of some of these bodies has been proved by
another most beautiful synthetical process, which has lately
come into use a process which enables us now not only to
say that we employ the volatile products of the distillation of
coal, but also the coke itself ; as carbonic oxide in combination
with chlorine (phosgene, or carbon oxychloride) is one of the
important agents used. This substance was discovered in 1812
by J. Davy.

In 1876, W. Michler gave an account of his researches on
the synthesis of aromatic ketones by means of phosgene
(Ber.y ix. 7 1 6), in which he showed by the action of this substance
on dimethylaniline that a tetramethylated diamidobenzophenone
was obtained. This substance has, therefore, the constitution

N(CH 3 ) 2 C 6 H 4 - CO - C 6 H 4 (CH 3 ) 2 N.

The formation of this product takes place in two phases, but I
need not enter into that now.

The first experiments to turn Michler's synthetically prepared
tetramethylated diamidobenzophenone to practical account were
made by Dr A. Kern, in the works of Bindschedler, at Basle.
Dr Kern proved that an agent like phosgene might be produced
on a larger scale, and he invented a process to convert Michler's
ketone base into methyl purple. This process was derived from
the ketone synthesis of triphenylmethane from benzhydrol
and benzene, and consisted in preparing the tetramethyldiamido-
benzhydrol, and condensing the latter with dimethylaniline ;
thus the leuco base of hexamethylrosaniline was obtained, and
then oxidised with lead peroxide. This process, which was too
costly for practical purposes, has been superseded by one
discovered by Dr Caro, who has found that this ketone base
can be made to form condensation products with dimethylaniline
and other products directly, by the use of phosphorus tri-

90 THE BRITISH COAL-TAR INDUSTRY

chloride this substance converting it first into a chloride, which
then reacts on the dimethylaniline, thus

N(CH 3 ) 2 C 6 H 4 - CC1 2 - C 6 H 4 (CH 3 ) 2 N + N(CH 3 ) 2 C 6 H 5

N(CH 3 ) 2 C 6 H 4V /C 6 H 4 (CH 3 ) 2 N,C1

+ HC1

N(CH 3 ) 2 C 6 H/

And this reaction takes place quantitatively, the body being so
pure that it readily crystallises from water in prisms, like
potassium permanganate, only with a very much more brilliant
lustre. These contain water of crystallisation. The condensa-
tion can also be effected with phosgene gas. The colouring
matter obtained by this means is bluer than that obtained from
dimethylaniline by oxidation, which consists chiefly of the
pentamethyl compound. 1

Diethylene can also be made into a ketone with phosgene
or carbon oxychloride, and this product condensed with diethyl-
aniline yields hexaethylpararosaniline.

Instead of dimethylaniline, dimethyl-a-naphthylamine can
be used, and in this case a beautiful blue colouring matter is
obtained, and if a-phenylnaphthylamine be employed, the
Victoria blue is produced, and by varying the reaction in this
kind of way a great variety of colouring matter can be
synthetically prepared.

With ammonia this ketone condenses to form the new yellow
colouring matter, auramine, with aniline phenylauramine. With
quinoline it produces a green very similar to Victoria or benzalde-
hyde green. I must not, however, spend any more time over
this interesting part of the subject, but may say here again we
have pure scientific research conducted for its own sake, bearing
fruit. The discovery of W. Michler, which remained for seven
years a matter of theoretical interest, now comes forward as a
matter of practical value.

ANTHRAQUINONE SERIES

I must now draw your attention to the important class
of colouring matter compounds obtained from anthracene or
anthraquinone.

1 See Caro, Eng. Patents, 4428, September 1883; 4850, i3th March
1884; and 5038, i8th March 1884.

COLOURING MATTERS FROM COAL-TAR 91

Alizarin and the other colouring matters related to it form
one of the most important branches of the coal-tar colour
industry, and one of special interest, because alizarin was the
first instance of the production of a natural colouring matter
artificially. It will be quite unnecessary for me here to say
much about the madder-root, which was the original source
of alizarin, and was grown in such enormous quantities, but
now is nearly a thing of the past ; nor will I enter into the early
chemical history of alizarin, and all the laborious work which
was bestowed upon it by Dr Schunck and others. As you are
probably all aware, the relationship of alizarin and its formation from
the coal-tar hydrocarbon anthracene was the result of the labours
of Graebe and Liebermann, the researches which culminated
in this being of a purely scientific nature. The original process
for obtaining it has, however, not been found of practical value,
but a new one in which sulphuric acid could be used in place
of bromine was afterwards discovered by Caro, Graebe and
Liebermann in Germany, and by myself in this country,
apparently simultaneously. A second process was also dis-
covered by me which was worked nearly all the time I was
engaged in this industry. In this, dichloranthracene was used
instead of anthraquinone, and the product thus obtained yielded
colours of a brilliancy which it has been found, even to the
present time, difficult to match by the anthraquinone process.

At the time of the discovery of artificial alizarin, anthracene
was not prepared by the tar distillers, as it had no application,
and very little was known about it. It was discovered in 1832
by Dumas and Laurent. In 185455, when studying under
Dr Hofmann, I worked with it for some time, but my results
were never published, because, owing to the erroneous formula
given to it by Dumas and Laurent, which was accepted, my
results would not fit in ; nevertheless the information obtained
afterwards proved of great value to me, although at the time
the labour spent appeared to be lost labour, showing the value
of research even when not successful. The formula of this
hydrocarbon was not established until 1862, when it was studied
by Dr Anderson. This was only six years before the discovery
of Graebe and Liebermann, and, had not the formula of
anthracene been established before these chemists commenced
their work, the relationship of alizarin to it would not have
been discovered, and up to this day it is possible that this

92 THE BRITISH COAL-TAR INDUSTRY

artificial alizarin industry would not have been in existence.
Researches like that of Dr Anderson I have often heard spoken
of slightingly, because they don't bear much on their surface ;
but who knows what such work may lead to ? Earnest workers
cannot be too much encouraged.

As anthracene was not a commercial product, it was necessary
to experiment on its production before alizarin could be
manufactured, and not only on the best methods of getting it,
but also to get a rough idea of how much could be produced,
because unless the hydrocarbon could be obtained in large
quantities, artificial alizarin could not compete with madder.
In our works at Greenford Green we commenced by distilling
pitch ; but afterwards tar distillers were induced to try to
separate it from the last runnings of their stills by cooling
and then filtering off the crystalline products which separated
out, and in fact visits were paid to most of the tar distillers
of the United Kingdom, others being corresponded with on
the subject, and the result was that in a short time such
quantities came in that the distillation of pitch was abandoned.
And although much doubt and anxiety prevailed at first as to
the possibility of getting a sufficient supply of this raw material,
two or three years since there were about 1000 tons of com-
mercial anthracene (about 30 per cent.) produced in excess of the
requirements, the annual production HI the United Kingdom
being estimated at about 6000 tons 30 per cent., or nearly 2000
tons pure anthracene.

Although the colouring matter obtained from anthraquinone
or dichloranthracene was at first simply considered as alizarin
more or less pure, yet on investigating the matter it was soon
found that it contained other colouring matter. To this I drew
attention in 1870 (Jour. Chem. Soc. y xxiii. 143, footnote), and in
1872 gave the analysis of a product which I named anthra-
purpurin, followed by a more extended account a year after-
wards (Jour. Chem. Soc., xxv. 659, and xxvi. 425). It was called
anthrapurpurin because it is an anthracene derivative having
the formula of purpurin, with which it is isomeric. In the latter
paper I also referred to another colouring matter dyeing alumina
mordants of an orange colour (Jour. Chem. Soc. y xxvi. 425).
It was also shown that anthraflavic acid when fused with alkali
gave a colouring matter behaving with mordants in the same
way (Jour. Chem. Soc. y xxvi. 26] and this has proved to be the

COLOURING MATTERS FROM COAL-TAR 93

same body. This latter reaction was afterwards more fully
studied by Schunck and Roemer, and the colouring matter
produced by it was shown also to have the formula of purpurin ;
they therefore called it flavopurpurin (Ber., ix. 678), so that the
colouring matters formed have proved to be three in number
alizarin, anthrapurpurin, and flavopurpurin, all of which are
valuable dyes, whereas in madder-root there is only alizarin
and purpurin, the latter being of but secondary value. This
can now also be produced from anthracene. The researches
which have been made on the subject of the conditions under
which these different colouring matters are formed, have led
to the discovery of methods for their separate production, so
that in artificial alizarin, which name commercially embraces
all these colouring matters, both mixed and separate, we have
more than a simple replacer of madder-root, and as these
colouring matters just referred to can be applied with the same
mordants, varieties of styles of work can be produced by the
calico printer and dyer which before were unknown. Anthra-
purpurin is, 1 believe, of as great importance as alizarin itself,
and used with it increases its brilliancy, and alone gives very
brilliant scarlet shades.

Artificial alizarin was first produced commercially in this
country by my firm at Greenford Green in 1869, when i ton was
produced ; in 1870, 40 tons were made ; in 1871, 220 tons, and
so on increasingly. It was not produced on the Continent
until 1871, when, according to Graebe and Liebermann, 125-150
tons were made. These weights do not apply to dry colour,
but to paste.

I cannot go into any lengthened account of the chemistry of
this industry here ; its development, however, has kept pace
with theoretical investigations, in some cases it may be said to
have forestalled it. For example, in the old methods of working,
more anthrapurpurin than alizarin was produced ; the conditions
required to modify this were found out by experiment.
According to all our previous knowledge as to the introduction
of hydroxyl into a body by the fusion of its sulphonic acid with
alkali, a monosulphonic acid should give a monohydroxyl com-
pound, and a disulphonic acid a dihydroxyl compound. There-
fore to produce alizarin, which is a dihydroxyl compound, an
anthraquinone disulphonic acid was thought to be the proper
thing to use. By experience this was gradually found to be

94 THE BRITISH COAL-TAR INDUSTRY

incorrect, a monosulphonic acid being required to produce
alizarin, a disulphonic giving anthra or flavopurpurin, the
colouring matter not being due to the primary but to a secondary
reaction, as was afterwards shown by research the mono and
dioxyanthraquinones (the latter known as anthraflavic and
isoanthraflavic acids) being the first products of the reaction, and
then undergoing oxidation by the caustic alkali employed,
yielding the corresponding colouring matter, a portion of the
products, however, being at the same time reduced back to
anthraquinone.

A very important improvement preventing this loss by
reduction was discovered by J. J. Koch, who found it might be
avoided by the use of a small quantity of potassium chlorate
with the alkali used in the fusion.

The amount of caustic soda used in this industry is very
large, and at the Badische Anilin- und Soda-Fabrik and, I
believe, elsewhere it is made on the spot ; and I must say the
cleanly way in which alkali is made in the above works contrasts
very favourably with what I have seen in some of the alkali
works in this country.

Like rosaniline, alizarin has now become a material for pre-
paring other colouring matters. Of these there are two in
use viz. nitroalizarin, which gives orange-yellow shades with
alumina mordants, and alizarin blue, a remarkable compound
prepared from nitroalizarin by treating it with sulphuric acid and
glycerol. This gives shades of colour like indigo. When first
discovered, considerable difficulty was found in its application
on account of its insolubility ; it has since been found to form
a soluble compound with sodium bisulphite, and by this means
its application has become much easier. The constitution of
the colouring matter derived from anthracene may be represented
as follows :

yCOv /OH* 1 '

Alizarin C 6 H 4 < >C 6 H 2 <

\:CX ' X)H (2 >

/
Purpurin C fl H 4 < /^g..^-^**.

XXX X)H< 4)

/CCX yOH (1)

Anthrapurpurin (m) HO C 6 H< >C (5 H 2 <

/ \OH (2)

COLOURING MATTERS FROM COAL-TAR 95

/COv /OH' 1 '

Flavopurpurin >HO C 6 H 3 <T >C 6 H 2 <

\rn/ \<

OH< 2 >

XV_,^K xV^n v '

Alizarin Orange C 6 H 4 < >C 6 H4OH' 2 '
^CO/ N NO 2 < 3

/COv yOH< 1J

Alizarin Blue C 6 H 4 <^

1(4)

CH=CH-CH

Those colouring matters under the name of artificial alizarin
are the most important of the coal-tar colours, their money value
amounting to more than a third of the entire value of all the
colours produced in this industry, and at present the price of
artificial alizarin compared tinctorially is not more than one-fourth
of that of madder or garancine before their production. There
are now three works producing it in this country, but the bulk
of that used still comes from Germany.

PHTHALEINES

The discovery of this class of bodies dates back to 1871,
and was the result of the investigation of Baeyer. He found
that phenols unite with a number of polybasic acids and with
aldehydes, with separation of water when the mixture is heated
alone, or with glycerol and sulphuric acid, the compounds formed
not being ethers. Those produced when phthalic anhydride is
employed, and which embrace those of practical value, are called
phthaleines. The first of these discovered by Baeyer was galle'm
(Ber.) iv. 457), produced by heating pyrogallol with phthalic
anhydride ; its formula is C 2 oH 14 O5 ; by reduction it loses
the elements of water and combines with hydrogen, forming
coerulem. These colouring matters, which for a long time
remained unnoticed, are now being extensively used.

Later, in 1871, Baeyer discovered resophthalein, or fluorescein
(Ber., iv. 555). This substance, which is remarkable for its
yellowish-green fluorescence, dyes silk and wool yellow, but
does not combine with mordants, and is not a very useful dyeing
agent. But it was discovered by Caro in 1874, the subject being
afterwards worked out jointly with Baeyer, that fluorescein when
brominated yielded that beautiful dyestuff now called cosine ;

9 6

THE BRITISH COAL-TAR INDUSTRY

this was introduced into the market in July 1874. Other sub-
stitution products were then studied, and the iodine product was
found to give bluer shades of red than the bromine derivative.
One of the most beautiful colours of this series is the dichlor-
tetraiodofluorescein, in the preparation of which dichlorophthalic
anhydride is used. It is called phloxine. The methylic ether of
eosine and its nitro derivative also have become commercial
articles. These bodies are now manufactured in a practically
pure condition. Their structure has been made out by research
to be as follows :

Fluorescein

Eosine. Tetra- | C 6 H 4
bromofluorescein > |
(Potassium Salt) ) C

C fi H 3 OH

C 6 H 3 OH

C 6 H.Br 2 (OK)

I
O

C 6 HBr 2 (OK)

Tetraiodofluorescein
(Potassium Salt)

C 6 HI 2 (OK)
i CAx / \
} \ COQ / C \

^C 6 HI 2 (OK)

Phloxine. Dichloro- ) C 6 H 2 C1
tetraiodofluorescein V |
(Potassium Salt). )

C 6 HI 2 (OK)
O
C 6 HI 2 OK

C 6 H 4 x. X C 6 H 2 (OH) 2
Gallein I >C< |
Y X O

C 6 H 2 (OH) 2

COO'

The introduction of these colouring matters had a great
influence on the manufacture of phthalic acid. This acid, it will
be remembered, was proposed a good many years since as a source
for the production of benzoic acid, which was largely in demand
for the manufacture of aniline blues, phthalic acid when carefully
treated with lime yielding calcium benzoate. But as phthalic acid
was required to be produced in an extensive way, new experi-

COLOURING MATTERS FROM COAL-TAR 97

ments had to be made on the subject. The difficulties connected
with this were surmounted by the Badische Anilin- und Soda-
Fabrik, who are now the chief manufacturers of this body and its
anhydride, which is the substance required ; when freshly pre-
pared it is one of the most beautiful products one can see.

Phthalic anhydride and dichlorophthalic acid are now also
manufactured for the preparation of the bluish shades of fluor-
escein derivatives already referred to. But this is not all ; it was
not only necessary to produce these in quantity, but it was neces-
sary also to produce resorcinol. This substance was originally pre-
pared from certain resins, e.g. galbanum by fusing it with potash,
or by distilling brazilin, etc. ; both technically impractical processes.
It was afterwards produced by fusing various halogen derivatives
of phenol and benzene sulphonic acid with alkali ; these also were
not practical processes. It was, however, eventually found that
it could be produced by fusing metabenzenedisulphonic acid with
potash, the original observation being made by Gallik ; and by
this process this product, which was a rare compound, is now
manufactured and has become a common one, being produced in
very large quantities.

INDIGO SERIES

Indigo is too well known a substance for me to make any
remarks in reference to its history as a colouring matter, and
with reference to the chemical side of the question I suppose
few substances have had more work bestowed upon them than
this body, so that I must confine my few remarks to its artificial
formation. There is one point of interest, however, connected
with indigo, and that is that it was the original source of aniline,
this base being discovered in the products of its destructive
distillation by Unverdorben, in 1826, as already mentioned.

Notwithstanding the large amount of work which has been
bestowed upon this colouring matter, its constitution has only
been lately arrived at, and for this, and the methods of its
artificial formation, we are indebted to the beautiful and laborious
researches of Baeyer. The first process for its artificial produc-
tion was patented by Baeyer in March 1880. The process
consists in preparing orthonitropropiolic acid and acting upon it
in presence of an alkali, with a reducing agent, such as grape
sugar, xanthate of sodium, etc. :

2[C 9 H 5 (N0 2 )0 2 ] + H 4 = 2C0 2 + C 16 H 10 N 2 2 + 2 H 2 O.

98 THE BRITISH COAL-TAR INDUSTRY

This process renders the application of artificial indigo very
easy in calico printing, because the products can be applied to the
fabric and the reaction then completed, and thus the indigo is
formed and fixed in the fibre ; and this process is in use in some
of the print-works of Mulhouse, where there is a continued
though small demand for orthonitropropiolic acid. Other
processes have been discovered by Baeyer for the formation of
indigo ; he has found that it can easily be formed from ortho-
nitrobenzaldehyde by condensation with bodies containing the
CH 3 CO group, such as acetone.

Hitherto this artificial formation of indigo has not met with
much practical success. This does not arise from difficulties in
its manufacture, but in its cost compared with natural indigo,
which is a very cheap dyestufF.

So far as it has been manufactured, however, the possibility
of this has been entirely dependent upon scientific research
disconnected with its study. To prepare nitropropiolic acid it is
necessary to begin with cinnamic acid as a raw material. This
acid, until 1877, was only obtained from certain balsams, and
was a very costly material. It was then discovered that it could
be produced with comparative ease by the action of acetic
anhydride and an acetate on benzaldehyde (Jour. Chem. Soc., xxxi.
428). Caro afterwards found that this process might be
simplified by heating a mixture of benzylidene dichloride with
sodium acetate, and it is by this process that it is now prepared.

The constitution of indigo Baeyer represents as follows :

C 6 H 4 CO CO C 6 H 4
NH C=C NH.

Several derivatives have been made which are interesting
dyes, such as methyl indigo, tetrachlor indigo, etc.

Azo COMPOUNDS

The commencement of the history of the azo colours in an
industrial sense has little to do with the theoretical side of the
question, the early products being the offspring of empirical
observations, and in no way connected with the theory of the
diazo compounds, a condition of things very different from that
now existing. Time will not allow me to enter into the beautiful

COLOURING MATTERS FROM COAL-TAR 99

work of Griess, much of which will be found in the Philo-
sophical Transactions for 1864.

The first definite compound of this class, shown to possess
dyeing powers, was a substance discovered by Prof. Church and
myself, known first as nitrosonaphthalene, then as azodinaphthyl-
diamine, but now called amidoazonaphthalene. This substance,
however, was of no practical value, because its salts, which are
violet, cannot exist except in the presence of a certain amount of
free acid. This substance has since been found of value in the
preparation of the Magdala red.

The first substance of this class sent into the market was the
phenylic analogue of amidoazonaphthalene viz. amidoazo-
benzene, which was discovered by Mene. It was introduced by
Nicholson, who prepared it by a process which has not been
published. It was afterwards patented by Dale and Caro in 1 863.
It is a yellow dye, but did not command success, because of its
volatility. It has, however, since become useful for the manu-
facture of induline.

The first really successful azo colour was Manchester or
Bismarck brown (triamidoazobenzene), which is produced by the
action of nitrous acid on metadiamidobenzene.

The next important step took place in 1876, by the discovery
of chrysoidine, by Caro and Witt. Independently, this product is
prepared by the action of diazobenzene on metadiamidobenzene.
About this time the subject began to be worked out on a
scientific basis, and since then the number of diazo dyes produced
is marvellous, and it will be useless for me to do more than
refer to one or two of the most important. About, this period
also the value of the sulpho group began to be realised, and this
has greatly added to the value of these dyes.

The first use of the sulpho group in relation to azo colours
was in connection with amidoazonaphthalene, patented by myself
in 1863.

During the early history of the coal-tar colours, innumerable
experiments were made with naphthalene derivatives to produce
colouring matters, but no results of any value were obtained ;
the experiments were mostly made with naphthylamine. The
first colouring matter that was obtained from it that was of value
was Martius's yellow, a dinitronaphthol. After this came the
Magdala red, which was not much used. The principal develop-
ment of the coal-tar colours of late years has, however, been in

ioo THE BRITISH COAL-TAR INDUSTRY

connection with diazo reaction. In these reactions /3-naphthol is
much used, and this product, which a few years ago was unknown,
is now manufactured by tons by fusing naphthalene sulphonic
acid with alkali, and is produced at a few pence per pound.
Most of the azo colours produced from benzene derivatives are
of a yellow or brown colour, but, by taking products of a higher
molecular weight, colours of different shades of red are produced.
The one which has commanded the greatest success is the scarlet,
first known as Meister's scarlet, produced by the action of
diazoxylene chloride on the disulphonic acid of /3-naphthol ; its
constitution may be represented thus :

C 6 H 3 (CH 3 ) 2 - N = N - C 10 H 4 (OH)(HS0 3 ) 2 .

In the formation of bluer shades, diazocumene chloride is used.
The cumidine used is now made from xylidene, by the beautiful
reaction of Hofmann's, in which an alcohol radical associated with
the nitrogen leaves that element, and enters into the hydrocarbon
radical. These scarlets have had a very injurious influence on
the cochineal market, and have in many cases displaced cochineal.
If a-diazonaphthalene chloride be used instead of the xylene
or cumene compounds, the colours known as Bordeaux are
produced. Then, again, where derivatives of a-naphthol are
used, different results are also obtained, so that great varieties of
products can be produced. The preparation of these azo colours
is a matter of great simplicity, the colouring matter being
precipitated by bringing the products together, and, moreover,
they can be produced in almost theoretical yields ; hence they
are remarkably cheap dyeing agents. The following are the
formulae of some of these azo dyes :

Bismarck Brown. NH 2 C 6 H 4 . N 2 . C 6 H 3 (NH 2 ) 2 HC1.
Chrysoidine. C 6 H 5 . N 2 . C 6 H 3 (NH 2 ) 2 HC1.
Fast Yellow. KSO 3 . C 6 H 4 . N 2 . C 6 H 4 NH 2 .
Manchester Yellow. NaSO 3 . C 6 H 4 . N 2 . C 6 H 4 NHC 6 H 5 .

Orange. NaSO 3 . C 6 H 4 . N 2 . C 10 H 6 (OH).

Fast Red. NaSO 3 . C 10 H 6 . N 2 . C 10 H 6 (OH).

Ponceau G. C 6 H 5 . N 2 . C 10 H 4 OH(NaSO 3 ) 2 .

Ponceau 2 R. (CH 3 ) 2 C 6 H 5 . N 2 . C 10 H 4 OH(NaSO 3 ) 2 .

Bordeau. C 10 H 7 .-N 2 . C 10 H 4 OH(NaSO 3 ) 2 .

COLOURING MATTERS FROM COAL-TAR 101

From which it will be seen that the colour changes from yellow
to red and claret by the increase of the molecular weight of the
radicals introduced, and also by the relative position occupied by
the groups, etc.

QUINOLINE COMPOUNDS

Products of the quinoline series have of late been claiming
attention in relation to colouring matters. It will perhaps be
remembered that, in the early days of the coal-tar colour industry,
a beautiful blue colour belonging to this series, discovered by
Greville Williams (Chem. News, nth Oct. 1860, 219), was intro-
duced. This substance was called cyanine. Its employment as
a dye for silk at first produced quite a sensation, on account of
the beauty of the colour ; but unfortunately it was too fugitive
to be of any practical value. Recent researches have shown that
chrysaniline is also to be regarded as a body of the quinoline
class. Alizarin blue, and the beautiful yellow dye obtained from
acetanilide by Fischer, and known as flavaniline, are found also
to belong to this class of substances.

Other colouring matters which have since been prepared
from quinoline direct might be referred to did time permit.
The peculiar green which is produced by the condensation of
tetramethyldiphenylketone with quinoline is of interest, because
the introduction of this quinoline has a very different influence
on the resulting colouring matter from that of groups containing
amidogen in fact, it appears to act more like phenyl, as the
green is very analogous to benzaldehyde green.

There is a very interesting new manufacture growing out of
the coal-tar colour industry, and that is the preparation of
derivatives of quinoline as substitutes for quinine. I have
mentioned that much work has of late been directed to the study
of quinine itself, and although the artificial formation of this
substance has not yet been discovered, new bodies have been
obtained during these investigations which are thought to possess
valuable medicinal properties. This is rather a remarkable
development from this industry, seeing that it is owing to
experiments made on the artificial formation of quinine that it
owes its foundation.

There is another peculiar colouring matter I have not yet
referred to peculiar, as it contains sulphur. I refer to
methylene blue, a very valuable dye, the constitution of which

102 THE BRITISH COAL-TAR INDUSTRY

has been so well worked out by Bernthsen. I feel I must be
content with this slight reference to it.

As 1 have shown, the coal-tar colour industry originated in
this country, where for some time it was solely carried on. The
second impulse was from France in the discovery of magenta and
its blue and purple phenyl derivatives, which were soon brought
to a state of great purity in this country. The Hofmann violets
were then discovered and produced also in this country, several
other colours being perfected and largely used. By this time
the manufacture of coal-tar colouring matter had made some
progress in Germany and Switzerland ; crude products in a cheap
form were first made, but improvements soon followed. The
subject of these colouring matters was taken up with great
earnestness in the German laboratories, so much so that it was
stated at one time that this industry was acting injuriously to
science, as it had diverted an undue amount of attention from
other subjects. Time has, however, proved the groundlessness
of this statement. This laboratory work, as well as research
work generally, fitted a number of highly trained chemists to
enter the colour works, where they soon improved the processes,
and thus they were able to produce products of a quality to
compete with those of English manufacture, which had, owing
to their purity, given superior and more reliable shades of colour
in the hands of the dyer ; and the result of the application of
such scientific labour to this industry is that Germany produces
products of the highest class and at the lowest price. The fact
that Germany is now the headquarters of this industry, raises
the important question, Why has England allowed this state of
things to come about ? All the raw materials are produced in
this country, both the products from coal and the other chemicals
required, and, as we have seen, the industry originated and was
first carried on here, and, in addition, we are the greatest con-
sumers of the colouring matters. This fact is well worth
considering, and it is many-sided. In my opinion, the patent
laws, and the difficulty of preventing infringements from abroad,
was one cause which may have prevented this country from
maintaining its first position.

When speaking of the early history of the first coal-tar colour
mauveine, I referred to this class of infringement and how it was
first met by the proceedings taken against the agents employed
in this country, and that this course was so far successful, but

COLOURING MATTERS FROM COAL-TAR 103

only pointed out how easily the law could be evaded if foreign
manufacturers gave up responsible agents and sold direct to the
consumers. There being no duties on such articles, no assistance
could be obtained at the Customs, and the colouring matters were
generally declared under the name of vegetable dyes or extracts,
so that it was impossible to stop them entering the country, and
even when found, owing to the onus of proof of their being
manufactured by the patentee's process resting with the patentee,
an almost insurmountable difficulty was raised, as in most cases no
traces of the products used in the preparation were left in the
colouring matter. The only other proceedings which could be
instituted were against the consumer ; here again the difficulties
were practically insuperable.

In most cases the consumers were using the patentee's
products to some extent, and it was impossible to know to what
extent ; in fact, without going into the many details connected
with this point, it may be assumed that in most cases proceeding
against a consumer of this kind of article is practically useless.

The result of this infringement, by importation from abroad,
is that a patentee had to compete against all other manufacturers
with the exception of his own countrymen.

There can be but little doubt that this state of things has
had much to do with preventing the development of this
industry, and crippling enterprise in this country, as it prevented
manufacturers even from working under royalties, there being no
security whatever except in name. Again, the fact that a
foreigner could take a patent in this country, manufacture in his
own country, and send the product here, was a great source of
loss and mischief to our trade. The new patent laws may
probably alter this, but still the difficulty of importation in
defiance of patent rights still remains.

There is another matter which tells much against this country
namely, that we are not able to export colour to foreign
countries upon the same conditions as foreign manufacturers can
into this, because we are met with import duties which handicap
us to a prohibitive extent, whereas the foreign manufacturer,
being protected in his own country, may maintain his prices
there and sell at a lower price in this country ; but what is still
more injurious, he may dispose of surplus production in this
country at or even below cost price. The injurious effect of such
a course upon our market can be easily understood by business

io 4 THE BRITISH COAL-TAR INDUSTRY

men, and I need not go into it here. These are matters our
manufacturers have to contend with, and cannot help themselves ;
there is, however, one matter in which they are undoubtedly
at fault.

We find that in Germany the manufacturer understands the
value of well-trained chemists, and sympathises with them ; they
also realise the value of theoretical chemistry this is a condition
of things we don't find in this country.

Unless I am mistaken, the coal-tar colour industry has acted
as the great stimulus to the development of general chemical
industries of Germany, and these, by starting with so much
scientific aid as they have called to their assistance, have made an
amount of progress during the last twenty-five years which is most
remarkable. Up to that time England had been the seat of most
of the large chemical industries, and the success which we have
had appears to me to have produced a feeling of false security,
and more attention has been paid by the heads of firms to the
markets than to the chemistry of their manufactures.

1 believe that thirty years ago there were very few chemists
employed in chemical works, either in this country or on the
Continent. Now there are very few without them ; but in this
country they are far less numerous and much less efficient than
in Germany, and for this our manufacturers are to a great extent
responsible. 1 am told that at some of our large chemical centres,
the chemists, or so-called chemists, are sometimes paid not more
than could be earned by a bricklayer. If such openings are put
by manufacturers before young men, their parents are not likely
to give them an expensive scientific training. If they get any,
they are not likely to continue it longer than enough to do
analysis very imperfectly, say by studying for about nine months.
An ordinary tradesman would not be considered efficient unless
he passed a much larger apprenticeship than this, but I know
teachers complain that it is difficult to get students who are to
be works chemists to stay longer than this. The result is that
when really efficient men are wanted, they are not to be found, and
they have to be got from abroad. In my address to the Chemical
Society last year, I referred to the past neglect of research at our
chemical schools, so that I need not speak further on that aspect
of the subject here, though it is an important one in relation to
our industries.

There is no chasm, as we have already seen, between pure

COLOURING MATTERS FROM COAL-TAR 105

and applied chemistry, they do not even stand side by side, but
are linked together, so that a technical chemist needs to be a
thorough chemist, and unless we employ such men we must be
at a great disadvantage in relation to foreign manufacturers.

I have now given a very brief, and therefore a very imperfect,
outline of the history of the coal-tar colour industry, an industry
to which none other can be compared for its rapid progress. I
have drawn your attention to the fact that it is the offspring of
scientific research, that in return, as I before stated, it has in
many cases given a fresh impulse to research by giving the
chemist new products, and also by opening up new subjects of
theoretical interest for consideration, and from the fruits thus
resulting again reaping further benefit. This linking together
of industrial and theoretical chemistry has undoubtedly been the
great cause of its wonderful development. We now have not
only all the colours of the rainbow, but we have also the more
sombre, but often not less useful, colours, and, moreover, there
are also great varieties of products of similar colour possessing
different properties which fit them for special uses. This industry
is also one of no mean dimensions. I have not been able to get
any very recent statistical information on this subject, but not-
withstanding the great reduction of prices of the products of late
years, yet, owing to the extended development it has undergone,
the value of the annual output has probably increased and not
declined, and from what information I have on the subject I
should say it is perhaps not less than ^3,500,000.

In my remarks I have also been led to refer to some of the
points connected with the migration of this industry from this
country to Germany, and the probable influence our patent laws
had upon this, to the matter of technical education, and the em-
ployment of high-class chemists in chemical works. This latter
subject is undoubtedly of great importance, and requires the
earnest consideration of our manufacturers. If it is found
profitable to employ chemists of this class on the Continent,
surely it should be found equally profitable to employ them here.
In conclusion, I am happy to say there are signs of the coal-tar
colour industry returning to our country, in part at any rate,
especially in relation to alizarin, for which there are now three
large works in existence, and the production of other colouring
matters is also increasing.

VII. : i886

RECENT PROGRESS IN THE
COAL-TAR INDUSTRY

BY PROFESSOR SIR H. E. ROSCOE, M.P., LL.D., F.R.S.
(Discourse delivered at the Royal Institution, i6th April 1886)

THOSE who have read Goethe's episodes from his life, known as
Dichtung und Wahrheit^ will remember his description of his
visit in 1741 to the burning hill near Dutweiler, a village in
the Palatinate. Here he met old Stauf, a coal philosopher,
philosophus per ignem^ whose peculiar appearance and more peculiar
mode of life, Goethe remarks upon. He was engaged in an un-
savoury process of collecting the oils, resin, and tar, obtained in
the destructive distillation of coal carried on in a rude form of
coke oven. Nor were his labours crowned with pecuniary
success, for he complained that he wished to turn the oil and
resin into account, and save the soot, on which Goethe adds that
in attempting to do too much, the enterprise altogether failed.
We can scarcely imagine, however, what Goethe's feelings would
have been could he have foreseen the beautiful and useful
products which the development of the science of a century and
a half has been able to extract from Stauf's evil-smelling oils.
With what wonder would he have regarded the synthetic power
of modern chemistry, if he could have learnt that not only the
brightest, the most varied colours of every tone and shade can be
obtained from this coal tar, but that some of the finest perfumes
can, by the skill of the chemist, be extracted from it. Nay, that
from these apparently useless oils, medicines which vie in potency
with the rare vegeto-alkaloids can be obtained, and lastly, perhaps
most remarkable of all, that the same raw material may be made
to yield an innocuous principle, termed saccharine, possessed of

106

RECENT PROGRESS IN COAL-TAR INDUSTRY 107

far greater sweetness than sugar itself. The attainment of such
results might well be regarded as savouring of the chimerical
dreams of the alchemist, rather than expressions of sober truth,
and the modern chemist may ask a riddle more paradoxical than
that of Samson, " Out of the burning came forth coolness, and
out of the strong came forth sweetness " ; and by no one could
the answer be given who had not ploughed with the heifer of
science, " What smells stronger than tar and what tastes sweeter
than saccharine ? " That these are matters of fact we may assure
ourselves by the most convincing of all proofs their money
value, and we learn that the annual value of the products now
extracted from an unsightly and apparently worthless material,
amounts to several millions sterling, whilst the industries based
upon these results give employment to thousands of men.

SOURCES OF THE COAL-TAR PRODUCTS

In order to obtain these products, whether colours, perfumes,
antipyretic medicines, or sweet principle, a certain class of raw
material is needed, for it is as impossible to get nutriment from a
stone as to procure these products from wrong sources. All
organic compounds can be traced back to certain hydrocarbons,
which may be said to form the skeletons of the compounds, and
these hydrocarbons are divisible into two great classes : (i) the
paraffinoid, and (2) the benzenoid hydrocarbons. The chemical
differences both in properties and constitution between these two
series are well marked. One is the foundation of the fats, whilst
the other class gives rise to the essences or aromatic bodies.
Now all the colours, finer perfumes, and antipyretic medicines
referred to, are members of the latter of these two classes.
Hence if we wish to construct these complicated structures, we
must employ building materials which are capable of being
cemented into a coherent edifice, and therefore we must start
with hydrocarbons belonging to the benzenoid series, as any
attempt to build up the colours directly from paraffin compounds
would prove impracticable. Of all the sources of hydrocarbons,
by far the largest is the natural petroleum oils. But these consist
almost entirely of paraffins, and hence this source is commercially
inapplicable for the production of colours. We have, however,
in coal itself, a raw material which by suitable treatment may be
made to yield oils of a valuable character. Of these treatments,

io8 THE BRITISH COAL-TAR INDUSTRY

that followed out in the process of gas-making is the most
important, for in addition to illuminating gas in abundant supply,
tar is produced which contains principally that benzenoid class of
substances already referred to, and which, to use the words of
Hofmann, "is one of the most wonderful productions in the
whole range of chemistry." The production of these latter as
distinguished from the paraffinoid group appears to depend upon
a high temperature being employed, to effect the necessary
decomposition.

The quantity of coal made into coke for use in the blast
furnace is larger than that distilled for gas-making, no less than
between eleven and twelve million tons of coal being annually
consumed in the blast furnaces of this country in the form of
coke, and being capable of yielding two million tons of volatile
products. Up to recent times, however, the whole of these
volatile products has been burnt and lost in the coke ovens.
But lately, various processes have been devised for preventing
this loss, and for obtaining the oils, which might be made avail-
able as colour-producing materials. It is, moreover, a somewhat
remarkable fact that only in one or two cases have the conditions
been complied with which render it possible to obtain the neces-
sary benzenoid substances. In the ordinary coking ovens, as
well as in the blast furnaces, although the temperature ultimately
reached is far in excess of that needed to form the colour-giving
hydrocarbons, yet the heating process is carried on so gradually
that the volatile products from the coal are obtained in the form
of paraffinoid bodies mainly, and hence are useless for colour-
making purposes. Amongst the few coking processes in which
the heat is suddenly applied, and consequently a yield of colour-
giving hydrocarbons is obtained, may be mentioned the patented
process of Simon-Carves, the use of which is now spreading in
England and abroad. The tar obtained in this process is almost
identical in composition with the average gas-works tar, whilst
the coke also appears to be equal for iron-smelting purposes to
that derived from other coke-ovens. A third source of these
oils yet remains to be mentioned, viz. those obtained as a by-
product in blast furnaces fed with coal.

Another condition has, in addition, to be considered in this
industry, and that is the nature of the coal employed for distilla-
tion. It is a well-known fact that if Lancashire cannel be ex-
clusively employed in gas-making a highly luminous gas is

RECENT PROGRESS IN COAL-TAR INDUSTRY 109

obtained, but the tar is too rich in paraffins to be a source of
profit to the tar-distiller, whilst, on the other hand, coal of a
more anthracitic character, like that from Newcastle or Stafford-
shire, yields a tar too rich in one constituent, viz. naphthalene,
and too poor in another, viz. benzene. It is also known to
those engaged in carbonising coal principally for the sake of the
tar that the coal from different measures, even in the same pit,
yields tars of very different constitution. That under these
varying conditions products of varying composition are obtained
is a result that will surprise no one who considers the compli-
cated chemical changes brought about in the process of the
destructive distillation of coal.

HISTORY OF BENZENE AND ITS DERIVATIVES

Having thus sketched the principles upon which the
formation of these valuable tar colours depends, we should do
wrong to pass over the history of the discovery of benzene
(C 6 H 6 ), which contributed so much to the unlocking of the
coal-tar treasury.

Faraday in 1825 discovered two new hydrocarbons in the
oils obtained from portable gas. One of these was found to be
butylene (C 4 H 8 ) ; to the other Faraday gave the name of
bicarburet of hydrogen, as he ascertained its empirical formula
to be C 2 H (C = 6). By exploding its vapour with oxygen, he
observed that one volume contains 36 parts by weight of carbon
to 3 parts by weight of hydrogen, and its specific gravity com-
pared with hydrogen is therefore 39- 1

Mitscherlich, in 1834, obtained the same hydrocarbon by
distillation of benzoic acid, C 7 H 6 O 2 , with slaked lime, and
termed it benzin. He assumed that it is formed from benzoic
acid simply by removal of carbon dioxide. Liebig denied this,
adding the following editorial note to Mitscherlich's memoir :
" We have changed the name of the body obtained by Professor
Mitscherlich by the dry distillation of benzoic acid and lime,
and termed by him benzin, into benzol, because the termination
c in ' appears to denote an analogy between strychnine, quinine,
etc., bodies to which it does not bear the slightest resemblance,
whilst the ending in c ol ' corresponds better to its properties and
mode of production. It would have been perhaps better if

1 Phil. Trans., 1825, p. 440.

no THE BRITISH COAL-TAR INDUSTRY

the name which the discoverer, Faraday, had given to this body
had been retained, as its relation to benzoic acid and benzoyl
compounds is not any closer than it is to that of the tar or coal
from which it is obtained."

Almost at the same time Peligot found that the same hydro-
carbon occurs, together with benzone, C 13 H 10 O (diphenylketone,
CO(C 6 H 5 ) 2 ), in the products of the dry distillation of calcium
benzoate.

The different results obtained by Mitscherlich and Peligot
are represented by the following formulae :

C 7 H 6 O 2 + CaO = C 6 H 6 + CaCO 3 .
(C 7 H 5 2 ) 2 Ca =C 13 H 10 O + CaC0 8 .

Peligot obtained benzene only as a by-product, exactly as in the
preparation of acetone (dimethylketone) from calcium acetate ;
a certain quantity of marsh gas is always formed.

It is not clear how Liebig became acquainted with the fact
that benzene is formed by the dry distillation of coal, as his
pupil Hofmann, who obtained it in 1845 from coal-tar,
observes : " It is frequently stated in memoirs and text-books
that coal-tar oil contains benzene. I am, however, unacquainted
with any research in which this question has been investigated."
It is, however, worthy of remark that about the year 1834, at
the time when Mitscherlich had converted benzene into nitro-
benzene, the distillation of coal-tar was carried out on a large
scale in the neighbourhood of Manchester ; the naphtha which
was obtained was employed for the purpose of dissolving the
residual pitch, and thus obtaining black varnish. Attempts were
made to supplant the naphtha obtained from wood-tar, which at
that time was much used in the hat factories at Gorton, near
Manchester, for the prepartion of " lacquer," by coal-tar naphtha.
The substitute, however, did not answer, as the impure naphtha
left, on evaporation, so unpleasant a smell that the workmen
refused to employ it. It was also known about the year 1838
that wood-naphtha contained oxygen, whilst that from coal-tar
did not, and hence Mr John Dale attempted to convert the
latter into the former, or into some similar substance. By the
action of sulphuric acid and potassium nitrate, he obtained a
liquid possessing a smell resembling that of bitter almond oil,
the properties of which he did not further investigate. This
was, however, done in 1842 by Mr John Leigh, who exhibited

RECENT PROGRESS IN COAL-TAR INDUSTRY in

considerable quantities of benzene, nitrobenzene, and dinitro-
benzene, to the Chemical Section of the British Association
meeting that year in Manchester. His communication is, how-
ever, so printed in the Report that it is not possible from the
description to identify the bodies in question.

Large quantities of benzene were prepared in 1848, under
Hofmann's direction, by Mansfield, who proved that the
naphtha in coal-tar contains homologues of benzene, which
may be separated from it by fractional distillation. On the i yth
of February 1856, Mansfield was occupied with the distillation
of this hydrocarbon, which he foresaw would find further
applications, for the Paris Exhibition, in a still. The liquid
in the retort boiled over and took fire, burning Mansfield so
severely that he died in a few days.

The next step in the production of colours from benzene and
toluene is the manufacture of nitrobenzene, C 6 H 5 NO 2 , and nitro-
toluene, C 7 H 7 NO 2 . The former compound, discovered in 1834
by Mitscherlich, was first introduced as a technical product by
Collas under the name of artificial oil of bitter almonds, and
Mansfield in 1847 patented a process for its manufacture. It is
now used for perfuming soap, but mainly for the manufacture of
aniline (C 6 H 5 NH 2 ) for aniline blue and aniline black and for
magenta. It is made on a very large scale by allowing a
mixture of well-cooled fuming nitric acid and strong sulphuric
acid to run into benzene contained in cast-iron vessels provided
with stirrers.

To prepare aniline from nitrobenzene, this compound is acted
upon with a mixture of iron turnings and hydrochloric acid in a
cast-iron vessel. Commercial aniline is a mixture of this com-
pound with toluidine obtained from toluene contained in com-
mercial benzene. Some idea of the magnitude of this industry
may be gained from the fact that in one aniline works near
Manchester no less than 500 tons of this material are manu-
factured annually. From the year 1857, after Perkin's cele-
brated discovery 1 of the aniline colours, up to the present day,
the history of the chemistry of the tar products has been that

1 See Lectures by Professor Hofmann, F.R.S., "On Mauve and Magenta,"
nth April 1862, and W. H. Perkin, F.R.S., "On the Newest Colouring
Matters," i4th May 1869, Proc. Roy. Inst.; also President's Address (Dr
Perkin, F.R.S.), Journal of Society of Chemical Industry, July 1885, "On
Coal-Tar Colours" (p. 75, ante).

ii2 THE BRITISH COAL-TAR INDUSTRY

of a continued series of victories, each one more remarkable
than the last.

COAL-TAR COLOURS

To even enumerate the different chemical compounds which
have been prepared during the last thirty years from coal-tar
would be a serious task, whilst to explain their constitution and
to exhibit the endless variety of their coloured derivatives which
are now manufactured would occupy far more time than is placed
at my disposal. Of the industrial importance of these discoveries,
the speaker reminded his audience of the wonderful potency of
chemical research, as shown by the fact that the greasy material
which in 1869 was burnt in the furnaces or sold as a cheap
waggon grease at the rate of a few shillings a ton, received two
years afterwards, when pressed into cakes, a price of no less than
one shilling per pound, and this revolution was caused by Graebe
and Liebermann's synthesis of alizarin, the colouring matter of
madder, 1 which is now manufactured from anthracene at a rate of
more than two millions sterling per annum ; and it is stated that
an offer was once made, in the earlier stages of its history, by a
manufacturer of anthracene to the Paris authorities to take up the
asphalt used in the streets for the purpose of distilling it, in order
to recover the crude anthracene.

Again, we have in the azo scarlets derived from naphthalene
a second remarkable instance of the replacement of a natural
colouring matter, that of the cochineal insect, by artificial tar-
products, and the naphthol yellows are gradually driving out the
dyes obtained from wood extracts and berries. It is, however,
true that some of the natural dyestuffs appear to withstand the
action of light better than their artificial substitutes, and our
soldiers' red coats are still dyed with cochineal.

The introduction of these artificial scarlets has, it is interesting
to note, greatly diminished the cultivation of cochineal in the
Canaries, where, in its place, tobacco and sugar are now being
largely grown.

Let us next turn to inquire as to the quantities of these
various products obtainable by the distillation of one ton of coal

1 "On the Artificial Production of Alizarin, the Colouring Matter of
Madder," by Professor H. E. Roscoe, Proc. Roy. Inst., ist April 1870 (see
p. 46, ante)-, also Dr Perkin, F.R.S., "On the History of Alizarin," Journal
Society of Arts, 3oth May 1879 (see p. 54, ante).

RECENT PROGRESS IN COAL-TAR INDUSTRY 113

in a gas-retort. The six most important materials found in gas-
tar from which colours can be prepared, are :

1. Benzene. 4. Metaxylene (from solvent naphtha).

2. Toluene. 5. Naphthalene.

3. Phenol. 6. Anthracene.

The average quantity of each of these six raw materials obtainable
by the destructive distillation of one ton of Lancashire coal is
seen in Table I. Moreover, this table shows the average amount
of certain colours which each of these raw materials yields, viz. :

1. I ., z iu 4- (Xylidine, 0-07 lb.).

2. } Ma 8 enta ' ' 62 3 lb - 5. Vermilline scarlet, 7-1 1 Ibs.

3. Aurin, 1*2 lb. 6. Alizarin, 2*25 Ibs. (20 per cent.).

Further it shows the dyeing power of the above quantities of
each of these colours, all obtained from one ton of coal, viz. :

*" > Magenta, 500 yards of flannel 27 in. wide.
3. Aurin, 120 yards of flannel.
4* I Vermilline scarlet, 2560 yards of flannel.
6. Alizarin, 255 yards Turkey-red cloth.

Lastly, to point out still more clearly these relationships, the
dyeing power of one pound of coal is seen in the lowest hori-
zontal column, and a parti-coloured flag, which exhibits the exact
amount of colour obtainable from one pound of Lancashire coal,
was exhibited.

Let us moreover remember, in this context, that no less than
ten million tons of coal are used for gas-making every year in
this country, and then let us form a notion of the vast colouring
power which this quantity of coal represents.

The several colours here chosen as examples are only a few
amongst a very numerous list of varied colour derivatives of each
group. Thus we are at present acquainted with about sixteen
distinct yellow colours ; about twelve orange ; more than thirty
red colours ; about fifteen blues, seven greens, and nine violets ;
also a number of browns and blacks, not to speak of mixtures
of these several chemical compounds, giving rise to an almost
infinite number of shades and tones of colour. These colours
are capable of a rough arrangement according as they are origin-
ally derived from one or other of the hydrocarbons contained in
the coal-tar. The fifty specimens of different colours exhibited

114 THE BRITISH COAL-TAR INDUSTRY

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RECENT PROGRESS IN COAL-TAR INDUSTRY 115

may thus be classified, but in this table, for the sake of brevity,
only the commercial names and not the chemical formulae of
these compounds are given (see Table II.).

Azo COLOURS

Amongst the most important of the artificial colouring matters
may be classed the so-called azo colours. These colours are
chiefly bright scarlets, oranges, reds, and yellows, with a few
blues and violets. They owe their existence to the discovery by
Griess, in 1 860, of the fact that the so-called azo group N=N
can replace hydrogen in phenols and amido compounds. But it
is to Dr O. N. Witt that is due the honour of having given the
first start in a practical direction to this class of azo colours by
the discovery of chrysoidine, and perhaps still more so by the
suggestions contained in a paper read before the Chemical Society.
Dr Caro, of Mannheim, was also acquainted with several com-
pounds which belong to this class at the time Witt published his
results, but it does not appear that he made practical use of them
until Witt introduced the chrysoidines and tropeolines. To
Roussin, of the firm of Poirrier of Paris, is due the credit of
having first brought into the market some of the beautiful azo
derivatives of naphthol. Griess, therefore, as the original dis-
coverer of the typical compounds and reactions by which the azo
colours are obtained, may be considered as the grandfather,
whilst Roussin and Witt are really the fathers, of the azo-colour
industry. Nor must it be forgotten that it is to Perkin we owe
the recognition of the value of the sulpho group in relation to
azo colours, a discovery patented in 1863. Moreover it is inter-
esting to note that changes in colour from yellow to red and
claret are effected by the increase in the molecular weights of the
radicals introduced as well as by the relative positions occupied
by these groups.

INDOPHENOL

Witt is also the discoverer of a new blue dyestufF termed
indophenol, which has been used as a substitute for indigo.
Certain difficulties, however, have arisen in the adoption of this
colour on the large scale. The most important use indophenol
is at present put to is for producing dark blues on reds dyed
with azo colours, both on wool and cotton. The piece goods are

n6 THE BRITISH COAL-TAR INDUSTRY

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RECENT PROGRESS IN COAL-TAR INDUSTRY 117

dyed a uniform red first, and then printed with indophenol white ;
for like indigo itself indophenol yields a colourless body on
reduction, and this being a very powerful reducing agent destroys
the azo colour, being itself transformed into indophenol blue.
The process works with surprising nicety and is very cheap.
The blue is formed and the red discharged with such precision
that patterns can be produced in which the blue discharge covers
a great deal more space than the original red. This new printing
process was devised by Mr H. Koechlin, of Lorrach. The reds
used for the purpose are in the case of wool the usual azo
scarlets, for cotton Congo red.

ARTIFICIAL INDIGO

About five years ago the speaker had the honour of bringing
before this audience l the remarkable discovery made by Baeyer
of the artificial production from coal-tar products of indigo blue.
Since that time but little progress has been made in this manu-
facture, as the cost of the process, unlike the case of alizarin, has
as yet proved too serious to enable the artificial to compete success-
fully in the market with the natural indigo.

Through the kindness of a number of eminent colour manu-
facturers in this country and on the Continent, the speaker was
enabled to illustrate his subject by a most complete series of
specimens both of the colours themselves and of their application
to the dyeing and printing of fabrics of all kinds. His thanks
are especially due to his friend Mr Ivan Levinstein, of Manchester,
for the interesting series of samples of cloth dyed with known
quantities of fifty different coal-tar colours, each having a
different chemical composition ; also to the same gentleman,
and to Messrs Burt, Boulton, & Hay wood, of London, for the
interesting and unique series of specimens indicating the absolute
quantities of products obtainable from one ton of coal, as well as
for much assistance on the part of Mr Levinstein in the prepara-
tion of the experimental illustrations for this discourse. To Dr
Martius of Berlin for a valuable series of colours, especially the
well-known Congo red, made by his firm, including samples of
wool dyed therewith, he is also much indebted. For the interest-

1 "On Indigo and its Artificial Production," Proc. Roy. Inst., 2;th May
1 88 1 (see p. 71, ante).

n8 THE BRITISH COAL-TAR INDUSTRY

ing details concerning indophenol and its applications the speaker
owes his thanks to Dr Witt and M. Koechlin.

COAL-TAR ANTIPYRETIC MEDICINES

Next in importance to the colour industry comes the still
more novel discovery of the synthetical production of antipyretic
medicines.

Up to this time quinine has held undisputed sway as a
febrifuge and antiperiodic, but the artificial production of this
substance has as yet eluded the grasp of the chemist. Three
coal-tar products have, however, been recently prepared which
have been found to possess strong febrifuge qualities, which if
still in some respects inferior to the natural alkaloids, yet possess
most valuable qualities, and are now manufactured in Germany
at H6chst and at Ludwigshafen in large quantity. And here it
is well to call to mind that the first tar colouring-matter discovered
by Perkin (mauve) was obtained in 1856 during the prosecution
of a research which had for its object the artificial production of
quinine.

In considering the historical development of this portion of
his subject, the speaker added that it is interesting to remember
that the initiative in the production of artificial febrifuges was
given by Prof. Dewar's discovery in 1881 that quinoline, the
basis of these antipyretic medicines, is an aromatic compound, as
from it he obtained aniline. Moreover, Dewar and McKendrick
were the first to observe that certain pyridine salts act as febri-
fuges. So that these gentlemen may be said to be the fathers
of the antipyretic medicines, as Witt and Roussin are of the
azo-colour industry.

Katrine, the first of these, was discovered by Prof. O.
Fischer, of Munich, in the year 1881, whilst engaged on his
investigations of the oxyquinolines. The febrifuge properties of
this substance were first noticed by Prof. Filehne of Erlangen.
Kairine is manufactured from quinoline, a basic product derived
from aniline by heating it with glycerin and nitrobenzene by the
following process. When treated with sulphuric acid, it forms
quinoline sulphonic acid, and this when fused with caustic soda
yields oxyquinoline, which is then reduced by tin and hydro-
chloric acid into tetrahydroxyquinoline, and this again on treat-
ment with ethyl bromide yields ethyl tetraoxyquinoline or kairine.

RECENT PROGRESS IN COAL-TAR INDUSTRY 119

The lowering of the temperature of the body by this compound
is most remarkable, though, unfortunately, the action is of much
shorter duration than that effected by quinine itself ; but on the
other hand, with the exception of its burning taste, it exerts no
evil effects such as are often observed after administration of large
doses of quinine. The commercial article is the hydrochloride,
the price is 855. per lb., and the quantity manufactured has lately
diminished owing to the discovery of the second artificial febrifuge,
antipyrine.

The following graphical formula shows the constitution of
kairine :

A
HC1

Antipyrine^ the second of these febrifuges, was discovered in
1883 by Dr L. Knorr in Erlangen, and its physiological properties
were investigated by Prof. Filehne of Erlangen. The materials
used in the manufacture of antipyrine are aniline and aceto-acetic
ether. The aniline is first converted into phenylhydrazine, a
body discovered by Emil Fischer in 1876. This body combines
directly with aceto-acetic ether, with separation of water and
alcohol, to form a body called pyrazol (C 10 H 10 N 2 O). The
methyl derivative of pyrazol derived by treating it with iodide of
methyl, is antipyrine, its composition being C U H 12 N 2 O. As a
febrifuge, antipyrine is superior in many respects to kairine and
even to quinine itself. It equals kairine in the certainty of its
action, whilst in its duration it resembles quinine. It is almost
tasteless and odourless, is easily soluble in cold water, and takes
the form of a white crystalline powder. Its use as a medicine is
accompanied by no drawbacks. It occurs in commerce in the
free state. The production of antipyrine, in spite of these
valuable qualities, is as yet small, its chief employment being in
Germany, where it has been successfully used in cases of typhoid
epidemic. The price is 6s. per lb.

Thalline, the third of the artificial febrifuges, is offered as
the tartrate and sulphate. It is manufactured by the Badische
Company. Thalline is said to be used as an antidote for yellow
fever. Its scientific name is tetrahydroparaquinanisol, and it was
first prepared by Skraup by the action of methyl iodide and potash
on paroxyquinoline.

120 THE BRITISH COAL-TAR INDUSTRY

We must, however, bear in mind that none of these syntheti-
cal febrifuges are antiperiodics, and therefore cannot be employed
instead of the natural alkaloid quinine in cases of ague or inter-
mittent fevers.

COAL-TAR AROMATIC PERFUMES

A third group of no less interest comprises the artificial
aromatic essences, and of these may here be mentioned, in the
first place, cumarin y C 9 H 6 O 2 , the crystalline solid found in the
sweet woodruff, in Tonka bean, and in certain sweet-scented
grasses. This is now artificially prepared by acting upon sodium
salicyl aldehyde with acetic anhydride by the reaction which is
associated with the name of Dr Perkin, and is used in the manu-
facture of the perfume known as " extract of new-mown hay."

A second interesting case of a production of a naturally
occurring flavour, is the artificial production of vanillin, the
crystalline principle of vanilla. Vanilla is the stalk of the Vanilla
planifolia, which encloses in its tissues prisms of crystalline vanillin,
to which substance it owes its fragrance. Tiemann and Harrmann
showed that vanillin is the aldehyde of methyl protocatechuic acid.

C 6 H 3 (OH)(OCH 8 )CHO. [CHO : OCH 3 : OH = i : 3 : 4].

The chief seats of the vanilla productions are on the slopes of
the Cordilleras north-west of Vera Cruz in Mexico, also the
island of Reunion, and in the Mauritius. Since the discovery of
the artificial production of vanillin, the growth of the vanilla has
been very much restricted.

A variety of vanilla, termed vanillon, obtained in the East
Indies, has long been used in perfumery for preparing " essence
of heliotrope." This contains vanillin together with an oil, which
is probably oil of bitter almonds. The essence of white heliotrope
is now entirely prepared by synthetical operations. It is manu-
factured by adding a small quantity of artificial oil of bitter
almonds to a solution of artificial vanillin ; when these substances
are allowed to remain for some time in contact, the mixture
assumes an odour closely resembling that of natural heliotrope.

VIII. : i886

THE SCIENTIFIC DEVELOPMENT OF THE
COAL-TAR COLOUR INDUSTRY

BY PROFESSOR R. MELDOLA, F.C.S., F.I.C.

(Journal of the Society of Arts^ 1886, p. 759)

IT will, I think, be conceded that the manufacture of coal-tar
products is par excellence the most scientific of the chemical in-
dustries. This high position may fairly be claimed for the
industry when we consider the number and complexity of the
products, the delicacy of many of the reactions employed, the
special arrangement of plant required, and the intimate knowledge
of the chemistry of the aromatic compounds which the colour
chemist must at the present time possess. Moreover, the
industry is of comparatively recent growth it has been born and
has reached its present development within the last thirty years,
so that the successive phases of its evolution can be clearly traced.
For these reasons the subject is well calculated to throw light
upon the general question of technical chemical education, a
question of which the importance to the country at large now
bids fair to become duly recognised.

In the brief historical sketch which I now propose to lay
before you, I shall mention only those discoveries which may be
considered to mark distinct commercial epochs in the develop-
ment of the industry. The successive steps in this development
will furnish us with one of the most striking illustrations of the
utilisation of scientific discovery for industrial purposes, and the
reaction of industry upon pure science.

Commencing in the year 1856, the foundation of the coal-tar
colour industry was laid by Perkin, by the discovery of mauve,

121

122 THE BRITISH COAL-TAR INDUSTRY

a violet dye, obtained accidentally in the course of an investiga-
tion having for its object the preparation of quinine by an artificial
synthesis. In 1860, magenta, which had formerly been made in
small quantities by expensive processes, was rendered a product
of the first order of commercial importance, by the discovery of
the arsenic acid process by Medlock and E. C. Nicholson simul-
taneously. During this same year, phenylated blues were first
produced by Girard and De Laire, by the action of aniline upon
a magenta base at a high temperature. These blues had but a
limited application owing to their insolubility, and their value
was enormously enhanced by Nicholson's discovery in 1862, that
these colours could be converted into soluble sulphonic acids.
The first azo colour, amido-azobenzene, a basic yellow dye, was
introduced in 1863, by the firm of Simpson, Maule & Nicholson,
under the name of aniline yellow. In this same year the
methylic and ethylic derivatives of magenta were manufactured
by the same firm, under the name of Hofmann violets, in
honour of their discoverer. Azodiphenyl blue, the first of the
colouring matters now known as indulines, and Manchester
yellow, appeared in 1864; and in 1866 Bismarck brown
(triamidoazobenzene) was first manufactured at Manchester.
The same year (1866) was marked by the introduction of
Coupler's nitrobenzene process for the manufacture of magenta.
In 1868, Graebe and Liebermann gave to the world their great
discovery of the chemical constitution of alizarin, and in the
following year the manufacture of this colouring matter from
anthracene was commenced. The first members of the great
family of the " phthalemes," viz. gallem and fluorescem, were
discovered by Baeyer in 1871 ; and the first technical application
of this discovery was made in 1874 by Caro, who introduced the
beautiful pink tetrabromfluorescem into commerce, under the
name of eosin. Diamidoazobenzene was discovered by Caro
and Witt independently in 1875, and was introduced into com-
merce by the latter as chryso'fdine. A great impetus was given
to the technical production of azo-colouring matters by this dis-
covery, the napthol oranges and other " tropoeolines," fast-red,
the ponceau scarlets, etc., appearing in 1878. Methylene blue
and acid magenta were introduced by Caro in 1877, an d i n the
same year the old and fugitive aniline yellow was converted
into a valuable acid yellow by Grassier, who patented a process
for converting the base into a sulphonic acid. Malachite green

SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 123

was introduced in 1878, and in 1879 the first member of the now
important group of secondary azo compounds appeared under
the name of Biebrich scarlet. It is these secondary azo scarlets,
and especially the croceine scarlets (discovered in 1 88 1), which
are exterminating the cochineal industry. The year 1880 was
marked by the brilliant discovery of the constitution of indigo,
and the synthesis of this colouring matter by Baeyer, a discovery
which is none the less a triumph of synthetical chemistry because
the manufacture is not at present successful from a commercial
point of view. Indophenols were introduced by Koechlin and
Witt in 1 88 1, and in 1883 appeared Caro's first patent for the
production of colouring matters of the rosaniline group by the
method of " condensation " with phosgene gas, in the presence of
suitable condensing agents.

This chronological record comprises nearly all the chief
colouring matters from coal-tar which are or have been of in-
dustrial value. It is important to note that the list, even as it
stands in the form of a bald statement of facts in chemical history,
reveals the existence of that fundamental law of the " survival of
the fittest." Old products have been displaced by newer ones,
as fresh discoveries were made, or processes improved, and to
the chemist it is of interest to observe how this development of
an industry has gone on part passu with the development of the
science itself. The moral conveyed to the manufacturer is
sufficiently obvious. If we are to recover our former supremacy
in this industry, we must begin by dispelling conservative ideas
we must realise the fact that no existing process is final, and
that no product at present sent into the market is destined to
survive for an unlimited period. The scientific manufacturer
must be brought to see that present success is no guarantee for
future stability, and unless he realises this position in its fullest
significance, he may find the sale of his standard products gradu-
ally falling off, or be compelled to wake up to the unpleasant fact
that his competitors are underselling him, owing to improved
methods of manufacture.

It may appear to many that I am here simply preaching the
doctrine of progress, and that the remarks which I have offered
are mere truisms. Unfortunately, the facts of the case render
this appeal necessary. It must never be forgotten that the coal-
tar colour industry is essentially of English origin. It was
Faraday who first discovered benzene in 1825 ; it was Mansfield

i2 4 THE BRITISH COAL-TAR INDUSTRY

who, in 1847, fi rst isolated this substance in large quantities from
coal-tar, and showed how nitro-benzene could be manufactured
therefrom. The beginning of the colour industry was Perkin's
discovery of mauve ; and the introduction of the new colour into
dyeing establishments was due to the example set by Messrs
Pullar, of Perth, in 1856. The manufacture of magenta on a
large scale was the result of the discovery of the arsenic acid
process by Medlock and Nicholson ; and the phenylic blues
were made commercially valuable by Nicholson. The first azo
colours, aniline yellow and Manchester brown, as well as Man-
chester yellow (dinitro-a-naphthol), were manufactured in this
country. We may thus fairly lay claim to have given to the
commercial world the types of all the more important colouring
matters of the present time. If, as is certainly the case, the
development of these typical products has been allowed to take
place in other countries, it behoves us, as a practical nation, to
inquire closely into the cause of this success abroad, a success
which will appear all the more remarkable when we bear in mind
that we are the largest European producers of the raw material,
gas tar, out of which the colours are manufactured, as well as
being among the largest consumers of the dyes themselves. It
is estimated that the amount of tar distilled annually in this
country is about 500,000 tons, and it is certain that we distil
at least one-half of the whole amount of tar produced in
Europe. The present state of affairs is that our competitors
can afford to import the raw materials from us, to manufacture
and return the colours so as to compete with us successfully in
our own markets, and to undersell us in the foreign markets.
The bare mention of these facts will be sufficient to indicate
the existence of something requiring radical reform in our
manufacturing system.

Before submitting to you the statistics of this industry which
I have been able to collect, I think it is desirable to make an
attempt to show the inner mechanism by which chemical science
has been and is being so successfully adjusted to commercial
wants by our Continental neighbours. I regret exceedingly that
my predecessors on this and other platforms have not left me
the chance of giving a general sketch of the chemical develop-
ment of the different groups of colouring matters. In fact, I
find myself suffering here from several distinct disadvantages, but
I hope, with your forbearance, to make the best of the situation.

SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 125

It will serve my purpose equally well, or perhaps even better, to
confine my illustration to one particular group of colouring
matters. The more striking achievements, such as the syntheses
of alizarin and indigo, are now so familiar to chemical audiences,
that their repetition would be unnecessary. Equally instructive,
from the present point of view, would be the history of the
colouring matters of the rosaniline group, and I can only express
a passing regret that time will not permit me to recapitulate the
steps in the beautiful series of investigations which led to the
establishment of the structural formula of rosaniline and its
derivatives by E. and O. Fischer, and then to the synthesis of
these colours by Caro from ketone bases. The principle which I
wish to bring out may seem a strange one to a " practical "
people, but I am convinced that the whole secret of success abroad
is the spirit of complete indifference to immediately successful
results in which the researches are carried on. I say, " immedi-
ately successful," because it would of course be absurd on the
part of an investigator not to take advantage of any discovery
which happened to be of commercial value. But, as a general
principle, the question of practical utility does not in the first
place enter into the work. The great development of this and
many other industries is mainly due to the complete and thorough
recognition, on the part of our competitors, of the vital import-
ance of chemical science. In this country, where the word
" practical " threatens to become a reproach, we put science into
the background, and attach all importance to the mere technique
of our manufactures. If I might venture to offer an aphorism
to the English manufacturer, it would be to the effect that he
should look after the science, and leave the technique to take care
of itself.

After these considerations, you will see that it is a matter
of perfect indifference whether I take by way of illustration
products which have been successful from a financial point of
view or not. In order to give greater emphasis to the principle,
1 propose, however, to consider the history of some colouring
matters which have found a market value, and I select this group
with the more readiness because, on the one hand, it was not
treated of last year by Dr Perkin, and, on the other hand, it
furnishes a splendid illustration of the way in which these coal-
tar products are being scientifically developed in the foreign
laboratories.

126 THE BRITISH COAL-TAR INDUSTRY

In 1863, Mr E. C. Nicholson discovered a basic orange
colouring matter among the by-products formed during the
manufacture of magenta by the arsenic acid process. The
method of isolating this substance in a state of purity was very
skilfully worked out by Messrs Simpson, Maule & Nicholson,
and the colour was introduced into the market under the name
of phosphine. This dye was the first basic orange discovered,
and the advantages which it possessed for certain kinds of dyeing
enabled the manufacturers to sell it at a price which helped to
cheapen the cost price of magenta to an appreciable extent. The
chemical composition of the substance was established in 1863
by Hofmann, who assigned the formula C2oHi 7 N 3 . H 2 O, and
described the base under the name of chrysaniline. Although
other and cheaper basic orange colouring matters have since been
discovered, chrysaniline still finds a distinct use ; and I am
informed by Messrs Brooke, Simpson & Spiller that the
amount of this colour now sold is not appreciably less than at
the time of its introduction by their predecessors. The chemical
constitution of chrysaniline remained unknown till about two
years ago, when the problem was solved by O. Fischer (Ber. y
1884, p. 203). In order to be able to follow the steps in the
investigation, it will be necessary, in the first place, to go back
to the discovery of another colouring matter, called flavaniline,
of which the existence was made known by O. Fischer and
C. Rudolph in 1882 (Ber., 1882, p. 1500). Flavaniline was
produced by the action of dehydrating agents, such as zinc
chloride, upon acetanilide, this fact having been observed by
Rudolph in i88i,and the practical manufacture of the colour
having been carried on under a patent by Messrs Meister, Lucius
& Brttning, of the Hoechst colour works. 1 Supplied with a large
quantity of the pure crystalline material by the manufacturers,
Messrs Fischer and Rudolph established the formula of flavaniline,
C 16 H 14 N 2 , and showed that its formation from acetanilide might
be expressed by the equation :

2 C 6 H 5 . NH . C 2 H 3 O - 2OH 2 = C 16 H 14 N 2 .

By the action of nitrous acid upon flavaniline a diazo compound
was produced which, by the usual method of decomposition by
water, gave a phenolic derivative termed flavenol, possessing

1 I am indebted to this firm for having kindly supplied me with specimens
of these products for exhibition.

SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 127

the formula C 16 H 12 N . OH, thus proving that flavaniline con-
tained a displaceable NH group. By heating flavenol with zinc
dust, a base was obtained having the formula C 16 H 13 N, and
termed flavoline. This base had an odour resembling that of
quinoline, and all its properties suggested to the authors that
flavaniline was in reality a quinoline derivative. That flavaniline
was amido-flavoline was proved by nitrating the latter base, and
reducing the nitro compound, when flavaniline was obtained.
In a later publication by Besthorn and Fischer (Ber. y 1883, p.
68) it was announced that flavenol, when oxidised by potassium
permanganate in an alkaline solution, gave an acid which, on
distilling with lime, furnished a base having all the characters of
lepidine. By the continued oxidation of flavenol with excess of
alkaline permanganate, another acid was obtained, which proved
to be picoline-tricarbonic acid, and the latter, on further oxidation,
gave picoline-tetracarbonic acid (Eer.^ 1884, p. 2925).

So much for the facts ; now for their interpretation. The
production of flavenol from flavaniline by the diazo reaction
shows that the respective formulas of these substances are :

C 16 H 12 (NH 2 )N C 16 H 12 (OH)N.

Flavenol gave, as the first product of oxidation, lepidine-
carbonic acid, of which the formula is Ci H 8 N(CO 2 H), and by
further oxidation it gave picoline-tricarbonic acid, of which the
formula is C 6 H 4 N(CO 2 H) 3 . Now the C-atoms oxidised by the
breaking down of the 1 6 -carbon atom flavenol into n -carbon
atom lepidine-carbonic acid, are those C-atoms which in flavenol
are associated with the hydroxyl group, because this group is no
longer contained in the product of oxidation. Thus the formulas
of flavaniline, flavenol, and flavoline are better expressed as :

C 10 H 8 N . C 6 H 4 (NH 2 )

C 10 H 8 N.C 6 H 4 (OH)

C 10 H 8 N.C 6 H 5 .

From this it appears that flavanaline is amidophenyl-lepidine,
flavenol hydroxyphenyl-lepidine, and that flavoline is phenyl-
lepidine.

The central nucleus of flavaniline having thus been shown to
be lepidine (which is methylquinoline), the next question to
be settled was the mode of formation of the colour base from
acetanilide. The authors suggest that at the high temperature

128 THE BRITISH COAL-TAR INDUSTRY

of the reaction, acetanilide, in the first place, becomes transformed
into the isometric orthoamidoacetophenone :

CH 3
? Hs rn/ C:0

^6 H 4<

C 6 H 5 .NH.C:0 X NH 2

Acetanilide. Amidoacetophenone.

By the condensation of two molecules of the amidoaceto-
phenone with the elimination of two molecules of water, flav-
aniline would be produced in a manner analogous to the
formation of mesitylene by the condensation of three molecules
of acetone under the influence of dehydrating agents :

CH 3 CH 3

/
C 6 H 4 <( | =C 6 H 4 < |

\N = |H 2 Oi = C - C 6 H 4 . NH 2 \N = C - C 6 H 4 . NH 2

The accuracy of this suggestion was verified by showing that
orthoamidoacetophenone is present in small quantity when the
reaction is arrested as soon as the formation of colouring matter
commences ; and conversely, when pure orthoamidoacetophenone
was heated with zinc chloride, flavaniline was produced in small
quantity.

We may be permitted to pause at this stage of the investiga-
tion before proceeding to consider the connection of this work
with the constitution of chrysaniline. These results cannot but
be regarded by chemists as a very beautiful piece of investigation ;
but the person of a " practical " turn of mind may possibly want
to know what bearing they have upon the question of market
value the question which the manufacturer but too frequently
considers as the only one of importance. Now, it is the essence
of chemical science as indeed of all other sciences that every
discovered fact is related to other groups of facts, and, although
the relationship may not at once be apparent, it is only a matter
of further development that is necessary in order to reveal
relationships which are obscure on account of our imperfect
knowledge. Thus the policy of looking at a chemical product
from the narrow point of view of immediate utility is not only
unscientific, but it is detrimental to the interests of the manu-

SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 129

facturer himself. Every new compound or process discovered
every structural formula established by legitimate investigation
may have an enormous influence, directly or indirectly, upon the
market value of products at present sent into commerce. Our
manufacturers must realise this if they wish to recover their
position in the coal-tar industry, or in fact in any other chemical
industry. There is no branch of manufacture so perfect as not
to be open to further improvement, and until the broad spirit of
scientific development is made to replace the suicidal policy of
immediate utility, our position as a manufacturing nation is not
likely to be improved.

In order to justify this digression by the particular instance
now under consideration, we must return to the work of Messrs
Fischer and Besthorn. The discovery that flavaniline was a
quinoline derivative was of importance as a principle, quite apart
from any immediate value attaching to the dyestuff itself . Up
to the time of this discovery, the quinoline derivatives had been
practically of no importance in the tinctorial industries, but as a
consequence of the present investigation the question at once
suggested itself whether the analogous bases of high boiling-point,
which are present in coal-tar, such, for example, as acridine,
might not be utilised as sources of colouring matters. I may
remind you that the fact of quinoline being an aromatic compound
was first established by the researches of our Chairman this
evening, Professor Dewar, who obtained aniline from this base.
In a subsequent paper on chrysaniline (O. Fischer and G. KSrner,
Ber., 1884, p. 203), it was pointed out that in the course
of his investigations upon rosaniline Fischer had observed that
the former base, like rosaniline, was capable of furnishing a
diazo compound. An observation made by Claus is also men-
tioned, viz. the conversion of chrysaniline into a phenol (chryso-
phenol) by heating to a high temperature with hydrochloric acid
in accordance with the equation :

C 16 H 15 N 3 . HC1 + H 2 = C 19 H 15 N 2 + NH 4 C1

Chrysaniline hydrochloride. Chrysophenol.

The investigation of flavaniline appears to have given an
impetus to the ideas respecting chrysaniline, because of the
general similarity in the properties of these two substances. In
confirmation of this impression, it was found that by the oxida-
tion of chrysophenol an acid was obtained which, on distillation

130 THE BRITISH COAL-TAR INDUSTRY

with lime, gave a pyridine base. I need hardly remind you
that picoline, which was obtained from the acid resulting from
the extreme oxidation of flavenol, is methylpyridine. It was
thus established that chrysaniline was a derivative of a quinoline
base.

The next step in the investigation is a very important one.
By decomposing the diazo compound of chrysaniline with
alcohol according to the Griess reaction, phenylacridine was
obtained. Acridine is a base belonging to the quinoline series,
having the formula C 13 H 9 N. It was discovered by Graebe and
Caro in 1872 in crude anthracene. Phenylacridine accordingly
possesses the formula Ci 3 H 8 N . C 6 H 5 ; and chrysaniline appears
as diamidophenylacridine Ci3H 7 (NH 2 )N . C 6 H 4 (NH 2 ), because
two amido groups are replaced by H by the diazo reaction.
Thus the formula C 2 oH 17 N 3 (first assigned by Hofmann to
chrysaniline) is really the formula of the higher homologue,
chrysotoluidine.

In order to explain the formation of chrysaniline during the
oxidation of the materials (aniline and toluidine) in the " red
melt " still, several suggestions were put forward, of which the
most probable appeared to be that the base was derived from
triamidotriphenylmethane, the latter compound resulting from
the condensation of two molecules of aniline with one of ortho-
toluidine :

/NH 2
C 6 H/ + 2C 6 H 5 . NH 2 - 2H 2 = HC(C 6 H 4 NH 2 ) 3

C^Hg Triamidotriphenyl-

methane.

/Ni H 2 /Nv

C 6 H/ =C 6 H 4 < | >C 6 H 3 .NH 2

\CH.HjC 6 H 3 .NH 2 -2H 2 \C/

I' C 6 H 4 .NH 2

C 6 H 4 .NH 2

Triamidotriphenylmethane. Diamidophenylacridine

= Chrysaniline.

The relationship of chrysaniline to the colouring matters of
the rosaniline group is thus indicated ; but, tempting as is this
theme, time will not admit of further digression into this field.
The main point, so far as we are at present concerned, is that
by means of the present investigation we have now arrived at
a knowledge of the parent substance, acridine, of which a
colouring matter more than twenty years old proves to be a

SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 131

derivative. By such results new fields of investigation are
opened up, and direct methods for the production of chrysaniline
suggest themselves. Even the practical requirements would be
satisfied if it could be shown that the colour could be manu-
factured cheaply by a direct synthesis, instead of depending, as
heretofore, upon the small and capricious secondary product of
the magenta manufacture. As a matter of fact, several syntheses
of chrysaniline have been effected, one of which forms the sub-
ject of a patent (German patent, 29142, April 1884) by Messrs
Ewer & Pick, of Berlin. Into the mode of preparation by
this patented process I cannot now enter any further than by
merely stating that nitrodiphenylamine and nitrobenzoylchloride
form the starting-points, and that the specification bears the
title, " preparation of chrysaniline and other colouring matters
of the phenylacridine group." If an elaborate scientific in-
vestigation culminates in a patent, its utility will, I know, be
conceded by many for whom the work would otherwise have
possessed no particular interest.

The illustration which I have given is a typical example of
the kind of scientific development which is being carried on by
our chemical colleagues abroad, and which is being taken ad-
vantage of in the Continental factories. I do not wish to give
you the impression that the particular colouring matters dealt
with are of supreme importance industrially they are of con-
siderable importance, but the modern history of any other
colouring matters would have been equally instructive. The
beautiful researches of Bernthsen upon the constitution of
methylene blue would have done equally well had time per-
mitted of my making use of them.

It was stated at the commencement of this paper that there
is reason to believe that our supremacy in the coal-tar colour
industry has, for some years, been declining, and I have further
expressed my belief that the chief cause of this falling off is the
subordinate position given to chemical science in this country as
compared with the status of this science abroad. Whether this
explanation be accepted or not, the fact of the decadence of the
manufacture remains, and I am in a position to bring this un-
pleasant truth home to our countrymen by a strong body of
evidence. It must be borne in mind that the decline of any
industry cannot be measured by the absolute weight of the
products turned out annually, because the demand for the pro-

1 32 THE BRITISH COAL-TAR INDUSTRY

ducts in question may be on the increase, and we may be
actually producing a greater weight of colours now than we
were during our most successful period. The whole question
is a relative one : it is simply, how much material are we now
turning out as compared with the amount produced by our
competitors what proportion of coal-tar products do we supply
for our own and foreign consumption ? In order to answer
this question with some approach to numerical exactness, it
occurred to me that the most trustworthy information could
be obtained from the consumers themselves ; and through the
kindness of Mr Robert Pullar, of Perth, and Mr Ernest
Hickson, of Bradford, I have been enabled to put myself into
communication with several of the representative dyeing and
printing establishments of this country. The facts obtained, as
showing the actual state of the industry at the present time,
appear to me of sufficient interest to be given here in some
detail. I may take the present opportunity of stating that my
application for statistical information has been most courteously
responded to by the various firms, to whom I have great
pleasure in returning my thanks.

Edward Ripley & Son, of Bradford, perhaps the largest
dyers of piece goods in the kingdom, inform me that during the
year 1885 they used 86J per cent, of foreign coal-tar colours,
and 13^ per cent, of English make.

Walter Walker & Son, of Dewsbury, dyers of wool for
rugs, mats, carpet yarn, and blanket stripes, estimate that during
1885 they used 80 per cent, of German dyes. They state that
the exact proportion is difficult to estimate, so that the figure
given is only approximative. Referring to their larger con-
sumption of foreign colour, they state : " It is very discouraging
to have to do this and send the trade out of our country, but
to our own interest and advantage we have to do it."

John Newton, silk dyer, Macclesfield. Mr Walter Newton,
F.C.S., informs me that during 1885 they used 80 per cent, of
foreign colour. He adds : " The rapid advancement in the
improved manufacture of some of these dyes by the Germans
is the only cause of our desertion from the English colour
manufacturer."

G. W. Oldham, silk dyer, of Netherton, near Huddersfield,
informs me that during 1885 he used 2000 Ibs. of German dyes,
1 100 Ibs. of English dyes, and 800 Ibs. of doubtful origin.

SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 133

James Templeton & Co., of Glasgow, state that they dye
as much as 30,000 Ibs. of yarn (chiefly worsted) weekly, but
they use only a small proportion of coal-tar dyes, all of which
are of German manufacture.

Messrs Leckie & MacGregor, of Paisley, inform me
that in the west of Scotland, including Glasgow and Paisley,
they are certain that at least 90 per cent, of the dyes used come
from the Continent. Their own consumption of English colour
only reached 6*8 per cent.

Alexander Harvey & Son, of Glasgow, yarn dyers, state
that during 1885 they used 60 per cent, of German and 40 per
cent, of English dyes. These figures do not include alizarin, of
which they state that they used about equal quantities of
German and English make. The English supply is chiefly
made up of one article, " aniline salt." They add : " We find
the German makes in general of better value than the British, as
our rule is, ceteris paribus, to give the home-make the preference."

Messrs Manson & Henry, Glasgow, yarn dyers, state that
they use only German dyes, adding that they find it to their
advantage "for both cheapness and quality."

Among the largest consumers of coal-tar colours in this
country are the jute dyers. As representing this department of the
tinctorial industry, Messrs James Stevenson, of Dundee, inform
me that during 1885 they used only 7*7 per cent, of English
colour. They have been good enough to supply the following
analysis of their consumption :

per cent., of which nothing is English.

6-4
nothing

nothing

Scarlet .

37 perc

Crimson

Blues .

ii-5

Oranges

Greens .

Magenta (resi

dues)

6 *5

Maroon

5'5

Pink

2-75

Brown

I>2 5

Violet

Various

100*0

1-25

nothing

Messrs Cox Bros., of the Camperdown Jute Works, Lochee,
state that practically the whole of the " aniline " colours used by
them are of Continental manufacture.

134 THE BRITISH COAL-TAR INDUSTRY

With reference to the calico-printers, the following facts have
been collected :

Messrs Z. Heys & Sons, of Barrhead, state that during
1885 they used over 10,000 Ibs. weight of colours (exclusive of
alizarin), of which 700 Ibs. only were of English make.

Messrs James Black & Co., of Bonhill, Dumbartonshire,
state that in their belief more than one-half of the colour used
by calico-printers is of foreign manufacture.

In the course of the present inquiry it seemed desirable to
obtain information concerning the consumption of alizarin, with
reference to which the following statements have been received :

Messrs Walter Crum & Co., of Thornliebank, Glasgow, are
of opinion that " the great bulk of what is used in this country
is manufactured in Germany." They do not profess to be able
to give actual figures having any approach to accuracy.

Mr John Christie, of the Alexandria Turkey-Red Works,
Dumbartonshire (John Orr-Ewing & Co.), states that they use
only artificial alizarin in their establishment, their consumption
being considerably over two million Ibs. weight of 10 per cent,
paste annually. Their consumption was in

1880 . 98 per cent. German. 2 per cent. English.

9 ?> * j

100 o

1881 .

1882 .

1883 .

1884 .

1885 .

77 2 3

5 6 i ' 44

47 >, 53

Messrs William Stirling & Sons, of Glasgow, state that
their relative consumption of English and German alizarin for
Turkey-red dyeing varies so much from year to year that they
have no means of directly supplying useful data. This firm has,
however, been good enough to make inquiries for me from a
competent authority, who has furnished the following report :

"In 1883 and 1884, I estimate that the sales (of alizarin) in
the United Kingdom amounted to a monthly average of about
530 tons, 10 per cent, (say, 6360 tons, 10 per cent, per annum).
Of this quantity, I estimate about 30-33 per cent, was manu-
factured in this country. Taking 1884 alone, the figures are
estimated at 566 tons, 10 per cent, per month (say, 6800 tons,
10 per cent, per annum). Proportion manufactured in Great
Britain, say, about 30-35 per cent. In 1886, the consumption
may be estimated at 550-600 tons, 10 per cent, per month (say,

SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 135

6900 tons, 10 per cent, per annum). Proportion manufactured
in this country probably now very considerably more than
35 per cent."

This estimate of the total consumption (550 600 tons,
10 per cent, per month) is confirmed by my friend Mr Thomas
Royle, F.C.S., of the British Alizarin Company's works at
Silvertown, but he is of opinion that 50 per cent, of this is of
English manufacture.

By way of further confirmation, it appeared to me to be
desirable to get the opinion of manufacturers themselves, and
although this has been a matter of considerable difficulty, I am
able to give some kind of an estimate. Mr Ivan Levinstein, of
Manchester, estimates that Germany produces :

Colours derived from benzene and toluene, six times more
than England.

Colours derived from naphthalene, seven times more than
England.

Colours derived from anthracene, five times more than
England.

The average production of Germany is thus about six times
that of this country. Mr W. A. Mitchell, of the firm of W. C.
Barnes & Co., Phoenix Works, Hackney Wick, informs me that
of some 159 tons of "aniline" dyes which passed through their
hands as agents last year, 95 per cent, were of Continental make.
With reference to the two chief raw materials, benzene and
aniline, this same firm estimates that about 75 per cent, of the
whole quantity of these products made in England goes to the
Continent. 1

The facts and figures which I have now laid before you must
be left to tell their own story time will not permit me to
attempt any analysis of them. The evidence collected will at
any rate give a much more forcible idea of the true state of
the coal-tar colour industry in this country than has hitherto
been attempted, and if this evidence goes against us as a
manufacturing nation, it is all the more desirable that our true

1 According to a later estimate, kindly supplied by Mr Ivan Levinstein
the quantity of benzene and toluene used in this country amounts to about
half a million gallons, and that used in Germany to about two million
gallons annually. About half the English production is, however, exported
as aniline, toluidine, and aniline salt, while Germany converts into colouring
matters at least 1,600,000 gallons of these hydrocarbons.

136 THE BRITISH COAL-TAR INDUSTRY

position should be realised. I find that it is almost impossible
to give a correct numerical expression in pounds sterling for
the annual value of this industry to the country, as the estimates
vary within very wide limits. According to Dr Perkin, whose
opinion on this matter will perhaps carry the greatest weight,
the value of the annual output is between ^3,000,000 and
^4,000,000. That the industry is one of considerable import-
ance on the Continent may be gathered from the official returns
relating to the German exports. For the following figures 1
am indebted to Dr H. Caro, of the Badische Anilin- und
Soda-Fabrik, Ludwigshafen on Rhine :

EXPORTED FROM GERMANY, FROM JANUARY i TO DECEMBER 31, 1885.

Alizarin paste (? per cent.) . . . 4283 tons.
Aniline and intermediate products . . 1713
Aniline, etc., colours .... 4645

Dr Caro adds that it is generally believed that about four-
fifths of the entire German production are exported.

The magnitude of this branch of chemical industry abroad
will be gathered from the fact that a German factory of about
the third magnitude consumes at the present time between 500
and 600 tons of aniline annually. According to information
recently furnished to me from the two largest of the German
factories, the Badische Company employ 2500 working men and
officials, and the Hoechst Colour Works (formerly Meister,
Lucius & Brttning) 1600 working men and fifty-four chemists.
It must of course be borne in mind that in these factories the
products are not "aniline" colours only, but alizarin, acids,
alkalies, and all chemicals required in this branch of manufacture.

The industry which has been selected for this evening's topic
is thus not only an important one in itself, but for us, as
chemists, its development is fraught with meaning both scienti-
fically and educationally. In taking up this subject it has not
been my desire to exalt the coal-tar colour industry to a position
of undue importance, nor do I wish it to be inferred that the
remarks which I have made concerning its decadence, or at any
rate stagnation, in this country are applicable to this manu-
facture only. The failure on our part to grasp the true spirit
of chemical science in its relation to our manufactures makes
itself felt in every industry in which chemistry is concerned.
The strength of our competitors is in their laboratories, and

SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 137

not, as here, upon the exchanges. It is only by showing up
our weakness in each industry that the state of affairs can be
remedied, and our prestige as a manufacturing country restored.
If each specialist would do for his industry what I have here
attempted to do broadly for the coal-tar colour industry, we
should get together a body of evidence which the Royal Com-
missioners on the depression of trade would do well to take into
consideration. We have heard a great deal of late years about
the subject of technical education, but the talk has been rather
one-sided. We have had utterances from those who, recognising
the enormous importance of this subject to the country, have
munificently endowed those institutions for the promotion of
technical education which are springing up around us ; we have
had all kinds of schemes from those who are taking upon them-
selves the duties of technical educators ; but it appears to me
that we have not heard with sufficient distinctness the voices of
those who may be presumed to suffer most from the want of
technical education, viz. the manufacturers themselves. I have
heard rumours of the existence of a certain class of manufacturer
let us hope a rare species who declares that science is no use
to him, and that he can get along better without it. I must
confess that I never met this individual in the flesh, but I know
that he exists in some of our manufacturing centres. As a
species he is, however, doomed to extinction in the struggle
with his competitors, and we may consider him out of court in
the discussion of schemes of technical Education. It is now
generally admitted that the days of empiricism have passed
away, and most manufacturers admit that present success and
future development depend upon a proper recognition of
technical, i.e. of applied, science. But unless the manufacturers
themselves speak loudly on this question, the voices of those
who wish to promote scientific education may be drowned by
the clamour of mere theorists.

In no other department of our manufactures is the want of
technical science more felt than in the chemical industries. We
not only see this in the greater development of these industries
abroad, but in some of our most successful factories here and
this applies more especially to the coal-tar colour industry
foreign chemists are employed, and, as I have lately been informed
by a well-known manufacturer, it is even impossible to get the
necessary plant properly made in this country. There is no

138 THE BRITISH COAL-TAR INDUSTRY

doubt that the recondite character of the truths of chemical
science, as compared with the more obvious truths of mechanics
and physics, has much to do with the want of popularity of this
branch of knowledge, and is responsible for the circumstance
that our science is regarded with comparative indifference until
some branch of manufacture is in extremis. In our national
characteristic of being " practical," we are apt to become short-
sighted in our manufacturing policy, and to recognise only
actualities to the exclusion of the potentiality conferred upon a
nation by a broader scientific culture.

DISCUSSION

Mr R. J. FRISWELL said, the great difficulty scientific men had
to encounter was to persuade those whose money interest placed
them at the head of large factories that scientific work, the practi-
cal outcome of which was not immediately visible, was really of
value. It was a long struggle, but he thought they were
beginning to see daylight at last. A feeling was beginning to
be awakened, not in the coal-tar colour industry alone, but in
others also, and he thought the coming generation of manu-
facturers would take to heart the lesson which Professor Meldola
and others had so strongly enforced, so that in the course of a
few years a great change would be seen in this direction. What
had been said with regard to the alizarin industry showed that
already in that direction a very marked change was beginning to
take place, and he hoped it would not be many years before they
saw a change in the same direction in other coal-tar colours.
Every Englishman must feel that it was a great reproach to this
country that an industry which originated here should so far
have slipped out of her grasp.

The Chairman (Professor JAMES DEWAR) said he desired most
heartily to thank Professor Meldola because he had not in any
way feared to tell the whole truth. When such a statement
came from a man who had not confined himself purely to the
scientific side of the question, but who had been himself superior
chemist in a large works, it showed that he was, from his thorough
knowledge of both sides of the question, entitled to speak in this
bold and straightforward way. He must differ from the writer
of the paper on one point, where he said he had never met the
manufacturer who declined to say that science was a great bene-

SCIENTIFIC DEVELOPMENT OF THE INDUSTRY 139

factor. On two occasions in his life he had certainly had this
experience. At one time, when a young man, he was offered
the same position that Professor Meldola held for several years,
and the difficulty which arose was entirely with reference to
supplying the laboratory. On another occasion a similar diffi-
culty arose with a very distinguished man, in which he projected
something of the same kind, but the moment he began to ask
where the materials were, and where the laboratory was, the
engagement was abruptly broken off, as this gentleman saw no
reason for having a laboratory in connection with the work at
all. There was the difference. It was not only the stimulus in
the large German laboratories, where active research was going
on, but it was the large stimulus now existent among the factories
themselves. There the men were not isolated, but, as they had
heard, there were something like fifty chemists in one large
factory, so that there was a little scientific world in itself, where
there was an incentive to continuous work. With reference to
the question as to the want of popularity in chemical science, he
admitted it, of course, but the question was, what was the full
explanation of it ? He thought it arose in a great degree from
the want of encouragement of chemistry in the older universities.
He said so, not because the older universities sent out a larger
number of men than the young ones, but simply because up to
the present time they had no such thing as even a creditable
chemical laboratory. Although he held the chair in one of these
universities, he was always ashamed if anyone asked to see the
chemical laboratory, because, in truth, there was none. It was
in the same condition as it was a century ago. If you got a pupil
out of the mass who showed some originality, you found you
could not retain him, you had not the materials or the money,
and consequently he went to some large German laboratory where
material was to be had, and where his work was encouraged. As
long as that went on, how could the science be popular ? Another
important point in the paper was the proof of the marvellous
result of action and reaction. Of course, as a physical principle,
that was admitted on all hands to be an elementary truth, but all
these facts now brought forward had had the most remarkable
effect as a stimulus on the growth of ; the more recondite scientific
investigation ; every new success connected with any colour which
might be discovered was a stimulus to further investigation, and
the result was that all the marvellous group of colouring matters

140 THE BRITISH COAL-TAR INDUSTRY

were now to be had in such enormous quantity that the chemist
got numerous new foci from which to start fresh investigations.
Consequently, all this industry had conversely affected chemical
laboratories, purely scientific, by the supply of splendid new
material.

Mr LIGGINS said it was impossible to overestimate the
brilliancy and beauty of these coal-tar dyes, or to give too much
praise to those chemists who had invented the processes which
had given such brilliant results, and as an artist he must say
it was impossible, either with oil or water-colour, to produce
colours of such beautiful shades as some of those which were
exhibited ; but there were two sides to every question, and
several times within the last few weeks the most thorough con-
demnation of aniline dyes had been pronounced in that room
by able men and scientific men, especially in connection with
the artistic work of Japan and India. The carpets of India
were said to be ruined by aniline colours which were used in
dyeing, and it was said to be one of the greatest misfortunes for
India that these colours had been introduced, as they were very
inferior to those the natives had been for centuries in the habit
of using ; besides that, it was very commonly supposed that the
colouring matters of various articles of clothing were poisonous.

Professor MELDOLA said, with regard to the fugitiveness of
these colours, there was a great deal of misapprehension, and the
same with regard to the poisonous character of the dyes. A
great controversy had been carried on lately in Bradford before
the Society of Dyers and Colourists. Specimens had been sub-
mitted to careful analysis, in order to detect arsenic, because it
was known that some of these colours were made by means of
arsenic acid, and it was thought they might retain traces which
rendered them poisonous ; but the amount found was infinitesi-
mal. No doubt many of these colours were fugitive, but, on the
other hand, some of the alizarin colours, which were used for
dyeing carpet yarn, would bear exposure to light, and remain
unaltered long after the old vegetable colours had faded com-
pletely away.

IX.: i8 9 6

THE ORIGIN OF THE COAL-TAR COLOUR

INDUSTRY, AND THE CONTRIBUTIONS OF

HOFMANN AND HIS PUPILS

BY W. H. PERKIN, PH.D., D.C.L., F.R.S.

(Hofmann Memorial Lecture : Journal of the Chemical Society^ 1896, p. 596)

THE illustrious man whose lifework we are called on to com-
memorate was well known to very many of us, especially those
who had the privilege of being his students and assistants. We
can all recall the pleasure and interest with which we listened to
the lucid and graphic accounts of his researches which he used
to bring before the Chemical Society in years gone by ; and
great was felt to be the loss, not only to us, but also to the
country, when he left it for his fatherland : but now we mourn
a far greater loss, and one which we realise more and more
deeply as we consider the incidents of his remarkable career a
career of such incessant activity and brilliant achievement.

I am charged with a duty which I wish had been placed in
more capable hands than mine : to give an account of the rise
and progress of the coal-tar colour industry, and its relation to
the Hofmann school ; and, as being connected with its com-
mencement, I am requested to make the account to a large
extent autobiographical a part of my task which it would have
been more agreeable to me to have seen undertaken by others
rather than myself.

This industry holds an unique position in the history of
chemical industries, as it was entirely the outcome of scientific
research. We have to go back to 1825, when Faraday discovered
benzene, or, as he then termed it " bicarburetted hydrogen," for
the first investigation which clearly bears upon the subject.

141

i 4 2 THE BRITISH COAL-TAR INDUSTRY

Faraday separated the hydrocarbon from the liquid products
condensed on compressing the gas obtained from oil. A year
later (1826), Unverdorben obtained aniline by the mere distilla-
tion of indigo, and called it " crystalline." Runge afterwards
obtained it from coal-tar oil, and having observed that it produced
a violet-blue coloration with chloride of lime, called it " kyanol."
It was subsequently obtained from indigo by Fritsche by distilling
this colouring matter with caustic alkali. We then come to the
important work of Mitscherlich, who obtained the hydrocarbon
benzene from a new source, namely, benzoic acid, whence the
name, and produced from this nitrobenzene. Zinin subsequently
found that benzidam, as he termed it, could be produced by the
action of sulphuretted hydrogen in presence of ammonia on an
alcoholic solution of nitrobenzene.

This brings us to the commencement of Hofmann's researches
on aniline, a substance which he used sometimes to speak of as his
" first love." In his first published paper he showed that Unver-
dorben's crystalline, Runge's kyanol, Fritsche's aniline, and Zinin's
benzidam were all the same compound, for which he afterwards
selected Fritsche's name, aniline. Later on, Hofmann and
Muspratt prepared toluidine from toluene from tolu balsam.

The work on the separation of aniline from tar was done
before the date of Hofmann's coming to this country, viz. in
1 843. After his arrival here in 1 845, he continued his researches,
and, to realise something of his indomitable perseverance, it is
necessary to remember that, until the coal-tar colour industry
was established, practically all the aniline he used in his numerous
inquiries was procured by the laborious and costly process of
distilling indigo with potash.

In 1843, organic chemistry was still in its infancy, and coal-
tar naphtha had not yet been investigated. Runge had isolated
carbolic acid, pyrrol, kyanol or aniline, and leucol or quinoline.
Naphthalene was well known to exist in tar, having been separated
by Garden, as early as 1820. Dumas had discovered para-
naphthalene or anthracene, and chrysene and pyrene had been
referred to by Laurent, but these were very doubtful compounds.
This was about all that was known of the composition of coal-tar
at that time. Hofmann showed, in 1845, tnat benzene must
exist in the naphtha, as he found that aniline could be produced
from it, but he never separated this hydrocarbon ; shortly after-
wards, however, he induced his pupil, Charles Mansfield of

HOFMANN MEMORIAL LECTURE 143

whom he always spoke in the highest terms to undertake the
investigation of the liquid hydrocarbons of coal-tar.

On reading over the account of Mansfield's investigation,
and bearing in mind that in those days fractional distillation was
conducted in old-fashioned glass retorts with the thermometer in
the liquid, it is impossible not to admire the patience and per-
severance he exercised, as well as the systematic and skilful
manner in which he worked.

All who have undertaken fractional distillations, even with all
our present knowledge and improved apparatus, know how diffi-
cult it is to detect and isolate products in a mixture such as coal-
tar naphtha. Yet Mansfield obtained benzene in a pure state, and
toluene sufficiently so for Hofmann to prepare toluidine from it.
He also obtained pseudocumene, and was led to believe in the exist-
ence of xylene. In describing his work, he modestly remarks :

" It has been perhaps the tedium of the methods necessary to
effect a separation of mixed hydrocarbons from each other which
has deterred experienced chemists from devoting their time to
disentangling the oils here treated off: and perhaps to have con-
ducted the innumerable distillations necessary for this purpose
in a laboratory imperfectly furnished with gas and other con-
veniences, would have been a task too laborious to have been
persisted in " (Jour. Chem. Soc., 1849, 1> 246).

Amongst the inquiries carried on by Hofmann, in the early
days of the Royal College of Chemistry, were those classical
" researches regarding the molecular constitution of the volatile
organic bases," in which he succeeded in displacing the hydrogen
of the NH 2 group by different alcohol radicles, eventually ob-
taining also the ammonium compounds. In the first of these
(Jour. Chem. Soc., 3, 1851) he describes ethylaniline (p. 284), and
diethylaniline (p. 288), also methylaniline (p. 295). The method
used in these researches, of substituting hydrogen in amines by
means of the iodides and bromides of the alcohol radicles, and
also the substituted anilines which were obtained, although not
connected with the foundation of the coal-tar colour industry,
have been of great value in its after development. These few
references to observations on the early work carried on at the
Royal College of Chemistry, for the sake of science only, show,
in fact, what valuable material was produced for the coming new
industry ; indeed, without the research of Mansfield, it could
never have become an industry.

i 4 4 THE BRITISH COAL-TAR INDUSTRY

The foregoing brings the work of the Royal College of
Chemistry up to near the date when I became a student there ;
and it will, perhaps, be well if I here refer to my young days,
and state how it came to pass that 1 had the good fortune to
study under Hofmann, especially as it will enable me to say a
few words in reference to one of his old pupils, Mr Thomas
Hall, B.A., who has done much for the cause of science.

As long ago as I can remember, the question of what pursuit I
should follow was constantly before me. Even when very young,
I interested myself in several subjects of a mechanical kind, and
worked at them to the best of my ability ; and elementary as the
experience then gained was, it had a lasting influence upon me.
When I was between twelve and thirteen years of age, a young
friend was good enough to show me some chemical experiments ;
amongst these were some on crystallisation, which seemed to me
most marvellous phenomena : as a result, my choice was fixed,
and it became my desire to be a chemist, if possible, as I saw that
there was in this science something far beyond the mechanical
and other pursuits I had been previously occupied with. At
this time I left the school I was attending, and entered the City
of London School, of which Dr Mortimer was then head master.
Here lectures were given on chemistry and natural philosophy ;
indeed, I believe this was the first school in which experimental
science was taught. The lecturer was one of the masters, Mr
Thomas Hall, an old student of Hofmann's who had obtained
all the chemical knowledge he possessed by working at the Royal
College of Chemistry. To attend these lectures was a source
of great pleasure to me. There was also a yearly examination in
science, and the examiner was also one of Hofmann's pupils,
and his first assistant, none other than my friend Mr, now Sir,
Frederick Abel. In the City of London School 1 was con-
sequently brought directly under Hofmannic influence, if I may
so term it, for all who came in contact with those who worked
with him had infused into them by induction his enthusiasm for
chemistry. Mr Hall very soon took an interest in me, and
installed me as one of his lecture assistants. Science, however,
was not allowed to interfere with the ordinary school curriculum,
so that the lectures, and the preparations for them, were delegated
to the interval for dinner, and being very much interested in pre-
paring the experiments, I not unfrequently found this interval
had passed before I left off work ; but, fortunately, I never

HOFMANN MEMORIAL LECTURE 145

found that the abstinence thus caused acted prejudicially upon
me. Whilst with Mr Hall, I heard much of the Royal College
of Chemistry and its Professor, and after my master had very
kindly had several interviews with my father who wished me to
be an architect and not a chemist it was my good fortune to
be allowed to follow my bent, and go to the Royal College of
Chemistry, in Oxford Street.

Before passing from my schooldays, I feel I must say a few
more words about my old schoolmaster, to whose kindness I
owe so much. Thomas Hall was a born teacher, who took an
individual interest in his scholars, studying their characters, and
stimulating any special qualities he saw they possessed, and, at
the same time, inculcating the highest moral qualities. He hated
anything that was mean or underhand, and, at the same time, was
very genial and kind-hearted ; this may be gathered from the
fact that the boys used to speak of him as Tommy Hall. His
influence on behalf of science, especially the science of chemistry,
was great ; it appears, from a list of old City of London School
boys, kindly given me by Mr John Spiller, that more than thirty
boys in whom he had taken an interest afterwards worked at the
Royal College of Chemistry, and of these I may mention the
following as having contributed papers to our Transactions :

J. J. Bowrey, J. T. Brown, Frank Clowes, W. H. Deering,
Edward Divers, J. A. Newlands, F. J. M. Page, W. H. Perkin,
Alexander Pedler, J. Spiller, and W. Thorp.

I entered the Royal College of Chemistry when I was in my
fifteenth year, at the time when that institution became part of
the School of Mines, but I only took up the study of chemistry.
After seeing Dr Hofmann with my father, the first person I
encountered in the laboratory was the Assistant, Mr W. Crookes,
who set me to study the reactions of the metals.

There was no theatre at the Royal College then, and the
students had to go to the Museum of Practical Geology in
Jermyn Street to hear the lectures on chemistry, which involved
a rather serious loss of time ; but the lectures made up for this,
as Hofmann spared no pains in making them as interesting, in-
structive, and perfect as he possibly could, illustrating, as far as
practicable, everything by experiment, so that the facts were
firmly impressed upon the mind. At that time he also had a
very efficient lecture assistant, the late Mr Witt. Hofmann was
good enough to let me attend these lectures a second time.

146 THE BRITISH COAL-TAR INDUSTRY

When going through the ordinary course of qualitative and
quantitative analysis, the students working at research appeared
to me to be superior beings, something beyond ordinary persons ;
and being possessed with a desire to join their ranks, the ordinary
course, and also gas analysis by Bunsen's method, was quickly
gone through. Hofmann then set me to work at research, and
very curiously gave me as a subject the hydrocarbon anthracene,
or, as it was generally called in those days, paranaphthalene. To
obtain this, pitch was taken as the starting-point, but as it was
found that this method of preparation was a very tedious one to
carry out in the laboratory, Hofmann kindly obtained some of
the crude product for me from Mr Cliff, of Bethels Tar Works.
As is well known, Hofmann especially at that period was
much interested in the formation of organic bases from hydro-
carbons, and the object of my investigation was to produce, if
possible, a nitro compound, and then convert this into a base by
reduction. However, anthracene refused to give a nitro com-
pound, and consequently no base could be obtained, but, in the
course of my work, I prepared the compound we now know as
anthraquinone, and also the chlorine and bromine derivatives of
anthracene. But these substances could not be got to yield in-
telligible results on analysis, and at that time it never occurred
either to Hofmann or myself that there was any likelihood of
Dumas and Laurent's formula for the hydrocarbon (i.e. C^H^)
being incorrect. The consequence was that this research was
set aside, but I shall show further on that the experience I then
gained was of great importance to me several years later, when I
commenced to work at the production of alizarin.

Hofmann next set me to work to study the action of chloride
of cyanogen on naphthylamine in the same way that he had
examined the action of this gas on aniline. In those days there
were no depots where pure products for research could be obtained
as there now are, and for this inquiry even the naphthalene had
to be purified in the laboratory ; this research was soon completed,
but was not written out and published until nearly twelve months
afterwards. It was brought before the Chemical Society when the
meetings were held in Mr Pepper's house in Cavendish Square.

Hofmann had a marvellous power of stimulating his students,
and of imparting to them his own enthusiasm ; he took the
strongest personal interest in their work, visiting three or four
times in the week even those who were going through the

HOFMANN MEMORIAL LECTURE 147

reactions, while those engaged in research work were seen daily
by him, and if anything of special interest was going on, more
than once in the day. His power of directing research was also
most remarkable ; with the aid of a few watch-glasses, a glass
rod, and a small gas flame he would make a number of experi-
ments, and from the information thus gained tell his students
how to proceed with their work. I well remember how one day,
when the work was going on very satisfactorily with most of us
and several new products had been obtained, he came up and com-
menced examining a product of the nitration of phenol which one
of the students had obtained by steam distillation ; taking a little
of the substance in a watch-glass, he treated it with caustic alkali,
and at once obtained a beautiful scarlet salt of what we now know
to be orthonitrophenol. Several of us were standing by at the
time, and, looking up at us in his characteristic and enthusiastic
way, he at once exclaimed, " Gentlemen, new bodies are floating
in the air." I mention this just as an example of the way in
which he used to stimulate us by his own example.

After I had completed the research on the action of chloride
of cyanogen on naphthylamine, Hofmann promoted me to the
position of an assistant in his research laboratory ; I was then
seventeen years of age. Mr A. H. Church, now Professor
Church, was among the assistants in the laboratory. This position
proved most valuable to me.

At this time Professor Cahours came over from Paris to work
with Hofmann on the allyl compounds, a research in which Pro-
fessor Church and I had to assist. They then commenced their
splendid work on the phosphorus bases, and I well remember the
excitement and interest which prevailed when Paul Thenard's
triethylphosphine was first produced by the action of zinc ethyl
on phosphorus trichloride, and Hofmann's delight when he found
it was vigorously acted on by methyl and also ethyl iodide, pro-
ducing white, crystalline, phosphonium iodides. 1 was occupied
with this research until I left the Royal College.

I may here refer to an incident which shows how greatly
Hofmann was interested in his scientific work. One day, when
he was going his usual rounds in the general laboratory, a student
standing not far from him poured a quantity of concentrated
sulphuric acid into a thick glass bottle he was holding in his hand,
which contained a small quantity of water ; the consequence was
that the heat evolved caused it to crack and the bottom to fall

148 THE BRITISH COAL-TAR INDUSTRY

out. Some of the acid splashed up from the floor into HofmanrTs
eye, and we feared would have a permanently injurious effect
upon it. Hofmann was sent home in a cab, and had to be kept
in bed in a dark room during several weeks, his old friend, Dr
Bence Jones, attending him. But during this time, and notwith-
standing his sufferings, he was so anxious about his work that we
used to have to visit him in his darkened bedroom, to report
progress and also to receive any instructions he had to give.

Whilst in the research laboratory I had the privilege of meet-
ing St Claire Deville, who came to London for the purpose of
exhibiting specimens of sodium and aluminium at a lecture given
by the Rev. T. Barlow at the Royal Institution, of which the
lecturer was Secretary.

Whilst assistant under Hofmann, I had but little time for
private work in the daytime ; as, however, I wished to continue
research work, part of a room at home was fitted up as a rough
laboratory, and there I was able to work in the evenings or during
vacations. In this laboratory a research was carried on conjointly
with Mr Church on some colouring matters derived from di-
nitrobenzene and dinitronaphthalene. One of the products we
then obtained afterwards proved to be amidoazonaphthalene, or,
as we called it, azodinaphthyldiamine. This appears to have been
the first case of a definite compound being obtained of the azo
class and shown to possess dyeing powers. As Dr Caro has
referred to this in his notice in the Berichte of the late Peter
Griess, I need not make any further observations on the subject
here (Ber., 1892, 25, 4, ion).

At this period much interest was taken in the artificial forma-
tion of natural organic substances ; but at the time I was at the
Royal College of Chemistry, although the theory of compound
radicles, the doctrine of substitution, etc., were occupying much
attention, very little was known of the internal structure of com-
pounds and the conception as to the method by which one com-
pound might be formed from another was necessarily very crude.

Thus, in the Report of the Royal College of Chemistry,
published in 1849, Hofmann refers to the artificial formation of
quinine as a great desideratum, and then states :

"It is a remarkable fact that naphthalene, the beautiful hydro-
carbon of which immense quantities are annually produced in the
manufacture of coal gas, when subjected to a series of chemical
processes, may be converted into a crystalline alkaloid. This

HOFMANN MEMORIAL LECTURE 149

substance, which has received the name of naphthalidine, contains
20 equivalents of carbon, 9 equivalents of hydrogen, and i
equivalent of nitrogen." (C = 6. O = 8.)

" Now if we take 20 equivalents of carbon, 1 1 equivalents of
hydrogen, i equivalent of nitrogen, and 2 equivalents of oxygen,
as the composition of quinine, it will be obvious that naphtha-
lidine, differing only by the elements of 2 equivalents of water,
might pass into the former alkaloid simply by an assumption of
water. We cannot, of course, expect to induce the water to
enter merely by placing it in contact, but a happy experiment
may attain this end by the discovery of an appropriate meta-
morphic process."

In fact there was but little other ground to work upon in
many instances than this kind of speculation.

As a young chemist I was ambitious enough to wish to work
on this subject of the artificial formation of natural organic com-
pounds. Probably from reading the above remarks on the
importance of forming quinine, I began to think how it might
be accomplished, and was led by the then popular additive and
subtractive method to the idea that it might be formed from
toluidine by first adding to its composition CJfri^ by substituting
allyl for hydrogen, thus forming allyltoluidine, and then removing
2 hydrogen atoms and adding 2 atoms of oxygen, thus

2(C 10 H 18 N) + 3 = C 20 H 24 N 2 2 + H 2

Allyltoluidine. Quinine.

The allyltoluidine having been prepared by the action of
allyl iodide on toluidine, was converted into a salt and treated
with potassium dichromate ; no quinine was formed, but only a
dirty reddish-brown precipitate. Unpromising though this result
was, I was interested in the action, and thought it desirable to
treat a more simple base in the same manner. Aniline was
selected, and its sulphate was treated with potassium dichromate ;
in this instance a black precipitate was obtained, and, on exami-
nation, this precipitate was found to contain the colouring matter
since so well known as aniline purple or mauve, and by a number
of other names. All these experiments were made during the
Easter vacation of 1856 in my rough laboratory at home. Very
soon after the discovery of this colouring matter, I found that it
had the properties of a dye, and that it resisted the action of light
remarkably well.

150 THE BRITISH COAL-TAR INDUSTRY

After the vacation, experiments were continued in the even-
ings when I had returned from the Royal College of Chemistry,
and combustions were made of the colouring matter. I showed
it to my friend Church, with whom I had been working, on his
visiting my laboratory, and who, from his artistic tastes, had a
great interest in colouring matters, and he thought it might be
valuable and encouraged me to continue to work upon it ; but
its evident costliness and the difficulties of preparing aniline on
the large scale, made the probability of its proving of practical
value appear very doubtful. Through a friend, I then got an
introduction to Messrs Pullar, of Perth, and sent them some
specimens of dyed silk. On I2th June 1856, I received the
following reply :

c< If your discovery does not make the goods too expensive,
it is decidedly one of the most valuable that has come out for a
very long time. This colour is one which has been very much
wanted in all classes of goods, and could not be obtained fast on
silks, and only at great expense on cotton yarns. I enclose you
pattern of the best lilac we have on cotton it is dyed only by one
house in the United Kingdom, but even this is not quite fast,
and does not stand the tests that yours does, and fades by
exposure to air. On silk the colour has always been fugitive :
it is done with cudbear or archil, and then blued to shade."

This somewhat lengthy extract is quoted because it gives a
glimpse at the state of the dyeing trade in reference to this shade
of colour at that period.

This first report was very satisfactory ; the " if " with which
it commenced was, however, a doubtful point.

During the summer vacation, however, the preparation of the
colouring matter on a very small, technical scale was undertaken,
my brother (the late T. D. Perkin) assisting me in the operations,
and, after preparing a few ounces of product, the results were
thought sufficiently promising to make it desirable to patent the
process for the preparation of this colouring matter. This was
done on 26th August 1856 (Patent No. 1984). A visit was then
made to Messrs Pullar's, and experiments on cotton dyeing were
made, but, as no suitable mordants were known for this colouring
matter, only the pale shades of colour, produced by the natural
affinity of the dye for the vegetable fibre, were obtained ; these,
however, were admired. Experiments on calico printing were
also made at some print works, but fears were entertained that it

HOFMANN MEMORIAL LECTURE 151

would be too dear, and, although it proved to be one of the most
serviceable colours as regards fastness, yet the printers were not
satisfied with it because it would not resist the action of chloride
of lime like madder purple.

Although the results were not so encouraging as could be
wished, I was persuaded of the importance of the colouring
matter, and the result was that, in October, I sought an interview
with my old master, Hofmann, and told him of the discovery
of this dye, showing him patterns dyed with it, at the same time
saying that as I was going to undertake its manufacture, I was
sorry that I should have to leave the Royal College of Chemistry.
At this he appeared much annoyed, and spoke in a very dis-
couraging manner, making me feel that perhaps I might be taking
a false step which might ruin my future prospects. I have some-
times thought that, appreciating the difficulties of producing such
compounds as aniline and this colouring matter on the large scale,
Hofmann perhaps anticipated that the undertaking would be a
failure, and was sorry to think that I should be so foolish as to
leave my scientific work for such an object, especially as I was
then but a lad of eighteen years of age ; and I must confess that
one of my great fears on entering into technical work was that it
might prevent my continuing research work, but I determined
that, as far as possible, this should not be the case.

Still, having faith in the results I had obtained, I left the
College of Chemistry and continued my experiments, and found
that not only aniline, but also toluidine, xylidine, and cumidine
gave a purple colouring matter when oxidised.

The following is a copy of the principal part of the complete
specification of the patent I took out at this time :

DYEING FABRICS

" The nature of my invention consists in producing a new
colouring matter for dyeing with a lilac or purple colour stuffs
of silk, cotton, wool, and other materials in the manner
following :

" I take a cold solution of sulphate of aniline, or a cold
solution of sulphate of toluidine, or a cold solution of sulphate
of xylidine, or a cold solution of sulphate of cumidine, or a
mixture of any one of such solutions with any others or other of
them, and as much of a cold solution of a soluble bichromate as

152 THE BRITISH COAL-TAR INDUSTRY

contains base enough to convert the sulphuric acid in any of the
above-mentioned solutions into a neutral sulphate. I then mix
the solutions and allow them to stand for 10 or 12 hours,
when the mixture will consist of a black powder and a solution
of a neutral sulphate. I then throw this mixture upon a fine
filter, and wash it with water till free from the neutral sulphate.
I then dry the substance thus obtained at a temperature of 100
C., or 212 F., and digest it repeatedly with coal-tar naphtha,
until it is free from a brown substance which is extracted by the
naphtha. Any other substance than coal-tar naphtha may be
used in which the brown substance is soluble and the colouring
matter is not soluble. I then free the residue from the naphtha
by evaporation, and digest it with methylated spirit, or any other
liquid in which the colouring matter is soluble, which dissolves
out the new colouring matter. I then separate the methylated
spirit from the colouring matter by distillation, at a temperature
of iooC. or 2 1 2 F."

Fresh quantities of colouring matter were prepared and taken
to Scotland, and, although the method of applying it by means
of lacterin (casein) was then found to give very good results,
yet the printers who tried it did not show any great enthusiasm ;
and even Messrs Pullar began to fluctuate in their opinion as to
the advisability of erecting plant for its manufacture, and wrote :
" Should it appear that it will not be of service to printers,
it will be questionable whether it would be wise to erect works
for the quantity dyers alone will require." In January 1867,
Mr R. Pullar, however, advised me to see Mr Thos. Keith, a
silk dyer of Bethnal Green, London, and, after making a few ex-
periments with the colouring matter, and exposing the specimens
he dyed to the light for some time, he was much pleased with the
result, and encouraged me to go on with its production.

I was then joined in the undertaking by my father who
was a builder, and had sufficient faith in the project to risk the
necessary capital and also by my brother, who also had a good
knowledge of building, and, as he had taken part in the pre-
liminary experiments on the preparation of the dye, his assistance
proved most valuable, especially as he was possessed of good
business capabilities. Plans were prepared and a site obtained at
Greenford Green, near Harrow, and in June 1857 the building
of the works was commenced.

HOFMANN MEMORIAL LECTURE 153

At this time, neither I nor my friends had seen the inside of
a chemical works, and whatever knowledge I had was obtained
from books. This, however, was not so serious a drawback as
at first it might appear to be, as the kind of apparatus required
and the character of the operations to be performed were so
entirely different from any in use that there was but little to
copy from.

In commencing this manufacture, it was absolutely necessary
to proceed tentatively, as most of the operations required new
kinds of apparatus to be devised and tried before more could be
ordered to carry out the work on any scale.

But the mechanical were not the only difficulties. Benzene
at this time was only made to a very limited extent, as there was
but little use for it, and it was only after making several inquiries
that it was ascertained where it could be obtained. That used at
first came from Messrs Miller & Co., of Glasgow. It was also
of very unequal quality, and required refractionating before use ;
its price was 55. per gallon. No nitric acid sufficiently strong for
the preparation of nitrobenzene could be obtained commercially,
and, as we did not want to complicate our works by manu-
facturing the substance, experiments were made with a mixture
of sodium nitrate and sulphuric acid, using the latter in rather
larger proportions than necessary to give an acid sodium sulphate.
This method was found to succeed on the small scale, but, when
working with large quantities, special apparatus had to be devised,
and a great many precautions had to be taken to regulate the
operation ; however, very large quantities of nitrobenzene were
made by it. Nitrobenzene had never been prepared in iron
vessels before this time.

It was only three years before the works were started that
Bchamp had made the interesting discovery that finely divided
iron and acetic acid were capable of converting nitrobenzene into
aniline ; had it not been for this discovery, the coal-tar colour
industry could not have been started. To carry this process out
on the large scale, special apparatus was also required, and, on
account of the energy of the action which takes place, special
precautions had to be adopted ; but no great difficulties were
encountered in this operation. Potassium bichromate at that
date fluctuated between 9fd. and nd. per lb., and was therefore
a costly product.

Many more details might be gone into in reference to the

154 THE BRITISH COAL-TAR INDUSTRY

difficulties to be contended against at the starting of the industry,
but sufficient has been said to give some idea of them ; however,
in less than six months after the building of the works was com-
menced, namely, in December 1857, aniline purple, or Tyrian
purple, as it at first was called, was in use for silk dyeing in Mr
Keith's dye-house.

But in dyeing large quantities of silk, difficulties were again
encountered, on account of the great affinity of the colouring
matter for the fibre causing unevenness, and some time was taken
up in experimenting on this subject, until eventually it was found
that by dyeing in a soap bath a very pure and even colour could
be produced. This process was afterwards found to be the most
suitable for dyeing silk with magenta, Hofmann's violet, and
many other colouring matters.

Aniline purple having now been proved to be an important
colouring matter, which could be produced on a manufacturing
scale, it attracted much attention, and, as a consequence, many
others commenced its manufacture, and began to experiment with
aniline, especially in France ; all kinds of oxidising agents were
used, but potassium dichromate still proved to be the best, the
next best being chloride of copper, the use of which was patented
by Dale and Caro, in 1860.

The French manufacturers were not long before they succeeded
in producing the colouring matter (the French patent being
invalid, owing to a mistake as to the date it was necessary to
take it out in reference to that of the English patent), and in
using it in dyeing their goods, both silk and cotton. The
calico printers of this country then began to be alive to the
necessity of following them, and this made the demand for the
aniline purple which the French now began to call mauve so
great that, notwithstanding the continued increase which had been
taking place in the works at Greenford Green, it could not be
kept pace with. At this time, a very beautiful archil colour had
been produced by Messrs Guinon, Marnas, & Bonnet, called
French purple ; this also was applied to calico printing, and the
printers in this country who could not get a supply of aniline
purple used this until their requirements could be met. A little
before this, Mr Pullar and I separately discovered a process for
mordanting cotton, so that it could be dyed with aniline purple to
any depth of colour, and thus it became of much more value to
the cotton dyer than it was so long as its natural affinity for the

HOFMANN MEMORIAL LECTURE 155

fibre could alone be relied upon. The process consisted in the
use of tannin and a metallic oxide.

For calico printing, the colouring matter was first applied in
combination with lacterin, albumin, or gluten, but endeavours
were soon made to find some new method by which these might
be dispensed with, and I worked for some considerable time
on this subject at the Dalmonach Print Works, Alexandria,
Dumbartonshire, where the colour was first practically used for
printing in this country. I devised a process, which consisted in
printing on a lead salt, converting this into a salt containing a
fatty acid by means of soap, and then dyeing in a soap bath con-
taining the colouring matter ; the fatty lead salt then took up the
colouring matter, whilst the soap prevented the white from being
stained ; this process was patented by myself and Mr Mathew
Grey. It produced beautiful shades of colour, but could not be
used where combinations with other colours were required, and
therefore did not prove useful.

Printers then experimented on the use of tannin and a
metallic oxide, the process used in cotton dyeing devised by
Mr Pullar and myself ; a modified form of this process has
become the most important used. Another process was also
very largely used, patented by M. Schultz and myself, which
consisted in forming an insoluble arsenite of alumina and colour-
ing matter on the fibre, the colours produced in this way being
very brilliant, as well as fast to washing. Before the aniline
purple could be introduced for dyeing woollen and mixed fabrics,
some weeks were also spent at Bradford in finding out suitable
methods of applying it.

Thus it will be seen that, in the case of this new colouring
matter, not only had the difficulties incident to its manufacture
to be grappled with, and the prejudices of the consumer over-
come, but, owing to the fact that it belonged to a new class of
dyestuffs, a large amount of time had to be devoted to the study
of its applications to dyeing, calico printing, etc. It was, in fact,
all pioneering work clearing the road, as it were, for the intro-
duction of all the colouring matters which followed, all the pro-
cesses worked out for dyeing silk, cotton, and wool, and also for
calico printing, afterwards proving suitable for magenta, Hofmann
violet, etc.

All this time a host of experimentalists continued making
trials with aniline and all kinds of chemicals, and early in 1859,

156 THE BRITISH COAL-TAR INDUSTRY

three years after the discovery of aniline purple, or mauve,
M. Verguin discovered fuchsine, also called magenta and roseine,
and, later on, rosaniline by Hofmann.

From what has been said above, it will be seen that the dis-
covery of this colouring matter was made under more favourable
auspices than that of mauve : everything was ready for its pro-
duction and application, it was also an easier product to manu-
facture and relatively to the aniline used was formed in much
larger quantities than mauve was, but it was not nearly so fast
against light, and when first experimented with I thought this
would have been very detrimental to its extensive use, remember-
ing the experience that I had gone through with mauve ; but
things had changed, and the love of brilliancy had begun to
outrun the regard for durability, indeed, as is well known,
magenta has proved to be one of the most successful of the
coal-tar colours ever discovered. M. Verguin's process was a
very remarkable one, and it has never transpired whether he
was led to it by any scientific reasoning or not ; it will be
remembered that it consists in heating commercial aniline and
anhydrous tetrachloride of tin nearly up to the boiling-point of
the mixture ; it was first carried out by Messrs Reynard Bros.,
of Lyons.

We were thus indebted to France for the second step in the
coal-tar colour industry. Soon other processes were invented for
the production of magenta, but the most practical one, after
M. Verguin's, was that in which mercury nitrate was used ; large
quantities of colouring matter were made by this method.

The fuchsine, or magenta, first made in France, was but very
imperfectly purified, and a good deal of that afterwards made in
Germany simply consisted of the " melt " produced by heating
aniline with mercury nitrate.

Being naturally interested in this new colouring matter, I
made many experiments with it, and in a lecture I delivered before
this Society, on i6th May 1861 (Jour. Chem. Soc. y 1862, 14,
230) (when I was honoured by the presence of Michael Faraday),
an account of some of the results obtained by its examination
was given, in which it was shown that it was the salt of an
organic base (a fact at that time believed in by some, but doubted
by others) precipitated by alkalis and at the same time dissolved
by them to some extent, yielding colourless solutions, and that
its nitrate could be obtained in the form of octahedra, having

HOFMANN MEMORIAL LECTURE 157

a beautiful green metallic reflection ; this was the first occasion,
I believe, on which it was described as a crystalline compound.
Attention was also called to the fact that its salts could not con-
tain oxygen, which was afterwards confirmed by Hofmann ; and
it was further pointed out that other products were formed along
with it, one possessing an orange colour (chrysaniline), and another
a purple colour (violaniline, mauvaniline, etc.).

In speaking of the manufacture of rosaniline in this country,
I must first refer to another of Hofmann's pupils, Edward
Chambers Nicholson, of the firm of Simpson, Maule & Nichol-
son, who brought the manufacture of this compound to a state
of perfection which, I believe, has not been surpassed so far as
purity is concerned up to the present time.

It is of interest to trace the manner in which Messrs Simpson,
Maule & Nicholson became connected with the coal-tar colour
industry. They were originally manufacturers of fine chemicals,
etc. When aniline purple was found to be successful, and was
exciting a great deal of interest, this and other firms were anxious
to manufacture it, and consequently wished to have a licence for
the purpose, but no agreement could be come to. They were
then very desirous of manufacturing nitrobenzene for our use in
producing aniline. At first they could not do this at a sufficiently
low price, but eventually succeeded in producing it cheaply enough
to make it worth our while to supplement our own make by
theirs, as the demand for aniline purple was then so rapidly
increasing. In this way they soon became considerable producers
of nitrobenzene ; they then set to work to prepare aniline, which
after a time they succeeded in doing. In this manner they
leisurely, as it were, became fully prepared to go a step further,
and become manufacturers of colouring matters.

Dr David Price at this time joined the firm, and Nicholson
and he apparently experimented with the products he had patented
in 1859, namely violin, purpurin, and roseine, obtained by oxidis-
ing aniline with lead peroxide ; these colouring matters, however,
were not found to be of practical value. They then turned their
attention to the newly discovered colouring matter, fuchsine.
This they commenced manufacturing, giving it the name of one
of Dr Price's products, roseine.

H. Medlock, another of Hofmann's pupils at the Royal
College of Chemistry, took out a patent on i8th January 1860,
for the production of magenta, by heating aniline with arsenic

158 THE BRITISH COAL-TAR INDUSTRY

acid ; eight days later, Nicholson filed a similar patent, but did
not proceed with it when he learnt what Medlock had done.
Medlock's patent is notorious for the amount of litigation that
arose owing to the occurrence in it of the word " anhydrous."
The formation of magenta by the use of arsenic acid proved in
the hands of Nicholson, and also of others, a great improvement
on the previous processes, and for a long time was the process
for the production of this colouring matter, until, in fact, it was
superseded by the use of nitrobenzene instead of arsenic acid.

One of the things Hofmann used to impress on those of his
students who were engaged at research work was the great
importance of preparing their products in as nearly pure a
condition as possible especially those which were to be submitted
to analysis ; some of us used to think that we should get as
good results by examining the substances when crystallised
fewer times than he required, especially when the products were
difficult to obtain and the quantities became smaller and smaller
on each recrystallisation ; but he was right. Nicholson, when at
the Royal College, made several investigations under Hofmann's
direction, studying the compounds of phosphoric acid with
aniline ; the formation of cumidine from cumene from cuminic
acid ; also caffeine and some of its compounds ; and, in con-
junction with F. A. Abel, he investigated strychnine. He also
appears to have been an adept at combustions, as he made the
combustion of benzene for Mansfield ; his name appearing also
in de la Rue's paper on cochineal as having made one of the
combustions of nitrococcusic acid. There is no doubt that
Hofmann's teaching as to the importance of working with pure
materials was strongly impressed upon Nicholson when carrying
on these researches, and that it greatly influenced him when he
became engaged in the manufacture of colouring matters. It is
only right to add that Dr D. Price, with whom he was for some
time associated in this industry, and whom I knew when at the
Royal College of Chemistry as a most thorough, painstaking,
and careful worker, would also second his efforts in this respect.
I may also add that I feel sure Hofmann's influence in this
direction had also a considerable influence on my own after-
career as a chemist.

At first Messrs Simpson, Maule & Nicholson supplied
magenta, or roseine, as they called it, to the dyers in alcoholic
solution, but afterwards, when they had obtained it in a pure

HOFMANN MEMORIAL LECTURE 159

condition, they sold it in crystals (usually the oxalate). In their
process of purification they boiled the crude solution of the
colouring matter with milk of lime, and collected the base which
deposited from the clear solution thus obtained, and from this
prepared the desired salts.

By this time the coal-tar colour industry had become one of
no mean dimensions in this country, and also in France, and
it was quickly developing in Germany and elsewhere. The
number of colours was also increasing, for not only had mauve
or aniline purple and fuchsine been discovered, but Girard and
De Laire had made their remarkable discovery of imperial violet
and blue de Lyon by heating aniline with fuchsine, thereby as
is now known phenylating this colouring matter.

When first speaking of fuchsine, I mentioned that it was
discovered by M. Verguin, and, from a practical point of view,
this may be considered correct. Nevertheless it appears to have
been first seen as far back as 1856, when Natanson (Annalen der
Chemie und Pharmacie, 1856,98, 297) observed that in heating
aniline and chloride of ethylene in a sealed tube to 200 C., the
mixture becomes of a rich blood-red colour ; Hofmann also,
in 1858, when acting on aniline with carbon tetrachloride, ob-
tained, besides carbotriphenyltriamine, a small quantity of this
substance as a secondary product, which he describes as " a very
soluble substance of a magnificent crimson colour." *

In the Report of the Exhibition of 1862 (Class II., sec. A,
p. 126), Hofmann, in speaking of the discovery of this colouring
matter, says : " It may be said to have been discovered at two
different times according as the question is considered from a
scientific or industrial point of view ; " and at p. 126:
" Industrially, the discovery of aniline red was made by Messrs
Verguin and Renard Brothers of Lyons/*

The investigation Hofmann made with the Nicholson pro-
ducts soon set at rest the conflicting views which at first existed
in reference to this colouring matter, and proved that it was a

1 About two years after M. Verguin's discovery of fuchsine, the use of
carbon tetrachloride and aniline as a means of preparing this colouring
matter was tried, for reasons connected with patent rights, by MM. Monnet
and Drury of Lyons. They first employed a temperature of ii6-ii8 C.
until the reaction between these two substances was over, and then heated
the product up to 170 or 180 C. By this means of working, they apparently
obtained a larger yield than Hofmann, but the process never became a
practical one. See Moniteur Scientifique, t. Hi., i5th January 1861.

160 THE BRITISH COAL-TAR INDUSTRY

well-defined triamine which he renamed rosaniline forming
salts free from oxygen. He then regarded the base, which had
the formula C 2 oH 2 iN 3 O, as a hydrate of the anhydrous compound
C 2 oH 19 N 3 . Hofmann examined many of the salts of rosaniline
those with one molecule of acid, the ordinary salts used in
dyeing, and the hydrochloride with 3 mols. of acid. He also
obtained the interesting compound, leucaniline, by treating
rosaniline with reducing agents, a compound which has its
representation in all triphenylmethane colouring matters. The
investigation is a memorable one, as being the first investigation
which gave correct information respecting the formula of a
coal-tar colouring matter.

It had been observed by manufacturers that some varieties of
aniline yield much more rosaniline than others, samples boiling
at temperatures much higher than the boiling-point of the pure
compound being found particularly adapted for the production of
the red ; and it appears that Nicholson had ascertained that pure
aniline was incapable of yielding rosaniline. Hofmann studied
this subject, using aniline prepared from indigo and from pure
benzene, and his experiments confirmed Nicholson's. The idea
then naturally suggested itself, that the toluidine contained in
commercial aniline might be the source of the colouring matter.
But, on making experiments with toluidine (orthotoluidine was
not then known) it was found that this base also was incapable
of producing the dyestuff; on taking a mixture of aniline and
toluidine, however, it was at once produced in quantity, showing
that both bases were necessary for its production (Report,
International Exhibition, 1862, Class II., sec. A, p. 130).

This discovery was of great importance and interest, and
explained most of the facts connected with the use of anilines of
different boiling-points. In the case of mauveine, this discovery
was not of so great importance as in the case of rosaniline, because
pure aniline yields a purple colouring matter (pseudomauveine),
as well as mixtures of aniline and toluidine.

Mauve had also been obtained in a pure crystallised condition,
but technically this was not found of much advantage, as the
colours obtained with it in this condition were only slightly
superior to those obtained with the less expensive precipitated
colouring matter which was usually supplied to the consumer.

Having examined aniline red or rosaniline, Hofmann was also
desirous of investigating aniline purple or mauve, but when he

HOFMANN MEMORIAL LECTURE 161

spoke to me on the subject, the colouring matter was already
under investigation in my own laboratory.

The crystallised aniline purple sent into the market was the
acetate of the base to which I gave the name mauveine. This
base is remarkable for its stability and tinctorial power. Its
investigation (Proc. Roy. Soc., 1864, 12, 713) showed that it
possesses the formula C 2 7H 24 N 4 , and that, unlike rosaniline, it is
not a hydroxy compound. Moreover, the base is a strongly
coloured compound of a blue-violet colour. When treated with
reducing agents, it yields a leuco compound, but this is so
sensitive to the action of oxygen that on exposure to the air it
instantly changes back to mauveine. Its ordinary salts are pro-
duced from i mol. of base and i mol. of acid. From a more
recent research on this colouring matter (Jour. Chem. Soc., 1879,
717), I have shown that a dihydrochloride and corresponding
platinum salt can be obtained, and the characteristic changes
which a solution of this substance in concentrated sulphuric acid
undergoes on dilution, namely, from a dull green to a blue, and
lastly to a purple, show that probably salts formed by the union
of mauveine with more than 2 mols. of acid exist. The ordinary
commercial product has also been shown to consist of two
colouring matters, one forming very soluble and apparently un-
crystallisable salts called pseudomauveine, having the formula
C 2 4H 2 oN 4 , and produced from pure aniline ; the other forming
less soluble and beautifully crystalline salts of the formula
C 2 7H 2 4N 4 , derived from paratoluidine and aniline. This colour-
ing matter, unlike rosaniline, does not freely undergo changes
with reagents on account of its great stability, so that few
derivatives have been obtained from it serving to elucidate its
constitution, which is still unknown.

Messrs Simpson, Maule & Nicholson, after engaging in the
manufacture of rosaniline for some time, undertook that of Girard
and De Laire's imperial violet and bleu de Lyon, obtained by
heating a salt of rosaniline with aniline (Pat., January 1861).

Mr Nicholson spent much time in studying the conditions
most favourable to the production of these compounds, especially
the blue, so as to obtain it in a pure condition, and in this he
was very successful. This was due to his knowledge of the
importance of using pure materials in its manufacture. The
rosaniline base he used was not merely the best he produced for
the preparation of rosaniline salts, but he purified it much further

1 62 THE BRITISH COAL-TAR INDUSTRY

by means of methylated spirit ; the aniline was prepared for the
purpose from the purest benzene he could obtain ; he also paid
much attention to the selection of the best acid to use in com-
bination with rosaniline, and found that weak organic acids, such
as acetic and benzoic acids, were the most suitable. In this way
he eventually obtained the blue in a condition of purification
unequalled by others.

Provided with the purified blue by Nicholson, Hofmann soon
discovered that the base had the formula C 38 H33N 3 O ; this he
regarded as a hydrate of the compound C 38 H 31 N 3 , of which he
obtained a hydrochloride of the composition C 38 H 31 N 3 HC1. The
blue was converted by reducing agents into a leuco compound.

As far back as 1850 (Phil. Trans., 1, 93, Jour. Chem. Soc., 3,
283), when engaged in his researches on the molecular constitution
of the volatile organic bases, Hofmann had endeavoured to displace
the hydrogen in aniline by phenyl, by heating it with phenol,
but was unsuccessful ; we can, therefore, easily understand his
delight when he found that on boiling rosaniline with aniline the
colouring matter became phenylated. The long-desired method
of effecting the displacement of hydrogen by phenyl had, in fact,
been discovered, and we find that no sooner had he recognised that
the blue was a triphenylrosaniline than he telegraphed the result
to Paris. 1 The Comptes rendus of the sitting of the Academy
of 1 8th May 1863 contains the following note :

" M. Le Secretaire Perpetuel communique une Courte Note
de M. Hofmann conue dans les termes suivants.

" Bleu d'Aniline. En poursuivant mes recherches sur les
couleurs d'aniline, je suis arrive a un resultat tres simple ; le
bleu d'aniline est la rosaniline triphenylique : une molecule de
rosaniline et trois molecules d'aniline renferment les elements
d'une molecule de bleu d'aniline et trois molecules d'ammoniaque."
The paper, communicating fuller details of his results on this
colouring matter, was read on 6th July of the same year (Compt.
rend.) 1863, 57, 25). Speaking in this paper of Nicholson, he
pays him this tribute : " That in him was united the genius of
the manufacturer and the habits of a scientific investigator."

1 Hofmann had made the discovery apparently on the same day, for
Professor M c Leod, who was his assistant at that time, gives me an entry
from his diary dated i8th May 1863, which runs thus: "The doctor told me
that he had made a fine discovery, and that aniline blue is the triphenylated
rosaniline. Rosaniline, C 20 H 19 N 3 H 2 O ; aniline blue, C 20 H 16 (C 6 H 5 ) 5 N 3 H 2 O."

HOFMANN MEMORIAL LECTURE 163

We find the discovery of the phenylation of rosaniline after-
wards bearing fresh fruit in the hands of De Laire, Girard, and
Chapoteaut, who established the remarkable fact that when boiled
with its own hydrochloride, aniline acted in a similar manner,
producing diphenylamine and ammonia ; by using aniline
hydrochloride and toluidine, they, in like manner, obtained
phenyltoluylamine (Compt. rend.) 1866, 63, 91).

Aniline blue having proved to be triphenylrosaniline, it was
soon seen that the different shades of violet imperial were
rosanilines more or less phenylated.

Nicholson also found that, on heating acetate of rosaniline to
200 215 C., ammonia was disengaged, and a purple colouring
matter produced, which he called regina purple. This substance
was found to be a monophenylrosaniline (patented 2oth January
1862).

One of the great obstacles in the way of the application of
aniline blue was its slight solubility in water, which rendered the
dyeing operations unsatisfactory ; this also militated against its
use in calico printing for some time (the most suitable process
for its use for this purpose first found being that of Schultz and
myself with arsenate of alumina, but with this long steaming and
afterwards clearing in a soap bath was required ; the colours thus
obtained, however, were very pure and very durable). Nicholson
naturally was very desirous of overcoming this obstacle, and no
doubt the well-known process of rendering indigo soluble by
dissolving it in sulphuric acid, and thus converting it into a
sulphonic acid, occurred to him ; at any rate, by experimenting
in this direction, he succeeded in obtaining the desired result and
patented the process (ist June 1862). Nicholson obtained two
sulphonic acids a mono and a tri the first being known as
Nicholson's blue, and the latter as soluble blue, and it is owing
to the discovery of these derivatives of aniline blue or triphenyl-
rosaniline that this colouring matter became of such importance.

This method of treating aniline blue was very interesting as
being the first instance of sulphonating an aniline colour, a
process which of late years has become of so much importance,
not only in rendering difficultly soluble dyes soluble, but
also in changing the chemical nature of the colouring matters,
and thus extending their applications as dyes, as in the case of
rosaniline sulphonic acid.

It was Nicholson who succeeded in isolating the yellow qr

164 THE BRITISH COAL-TAR INDUSTRY

orange colouring matter which is formed in the manufacture
of rosaniline ; he prepared it in a pure state, and called it
phosphine. Hofmann undertook the examination of this dye,
and showed that it is represented by the formula C 2 oH 17 N 3 ,
differing from that of rosaniline in containing 2 atoms of
hydrogen less ; the base is capable of forming salts with i or 2
molecules of hydrochloric acid, the nitrate being remarkable for
its insolubility.

After discovering that aniline blue or bleu de Lyon was a
triphenylrosaniline, Hofmann was very naturally inclined to
experiment on rosaniline with the agents he had used so success-
fully in his experiments on the molecular constitution of the
volatile organic bases, namely, the haloid compounds of the
alcohol radicles, to see what influence these radicles would have
if introduced into the base : he found that they had, like phenyl,
though not to the same extent, a blueing effect, the colour
changing from red to purple, and then to violet as the hydrogen
atoms were gradually displaced, colouring matters being produced
which were found to be of great beauty when applied to silk, etc.
In his first paper on these products (Compt. rend.) 1863, 57, 30),
he gives an account of the action of methyl, ethyl, and amyl
iodides on rosaniline, and amongst the products he obtained at
that time describes the highest ethylated derivative he had
succeeded in producing as the iodethylate of triethylrosamline,
C2oHi 6 (C 2 H 5 ) 3 N3 . C 2 H 5 I.

He patented the method of producing these colouring matters
on 22nd May 1863.

It is easy to see how Hofmann was led to the production of
these compounds in the regular sequence of his work, but it is
curious that E. Kopp had evidently prepared some of them as
long back as 1861. E. Kopp remarks in his paper in the
Comptes rendus, 1861, 52, 363, " I have only stated in my notice
these substitutions as a hypothesis, but their existence is very
real ; I have already obtained some of them, and it is a
remarkable thing that the red shade disappears, and is converted
into a violet, becoming bluer and bluer as the hydrogen is dis-
placed by the hydrocarbons." It appears that he sent some
specimens of his products to M. Dumas.

When Hofmann patented the use of methyl, ethyl, and amyl
iodides for the preparation of these colouring matters, it seemed
almost incredible that substances such as these, which had

HOFMANN MEMORIAL LECTURE 165

hitherto only been used in research, should be employed in the
manufacture of a dye ; but such circumstances have constantly
arisen in the history of this remarkable industry aniline itself,
the parent of artificial colours, being an example and nothing
now appears to be too rare or difficult to prepare, to be used in
its development.

It is difficult to understand why E. Kopp did not go on with
his work on these substitution compounds, unless it was owing
to the fact that rosaniline was expensive in his days, and he
considered the alcoholic haloids too costly to employ for practical
purposes.

The Hofmann violets were the most brilliant in colour of any
which had been produced, and proved not to be so costly as
might be anticipated, as the iodine from the ethyl iodide used
could be mostly recovered ; but these colouring matters have
not the stability of mauve or imperial violet, and at first it was
thought that their use would be limited, but the increasing
desire for brilliancy was still superseding that for stability, and
the result was, that these colouring matters were very largely
used, and interfered very considerably with the sale of the
mauve and imperial violets, except for pale shades of colour,
when, unless the colouring matter used be stable, the goods fade
so quickly as to be of little value.

The products formed on heating mauveine salts with aniline
apparently are not comparable with those obtained from ros-
aniline, and although the product becomes bluer no ammonia is
evolved ; from my later experiments, it seems most likely that
the aniline used takes no part in the change, the blueing being
a change in the colouring matter, the consequence of the
temperature employed.

When treated with ethyl iodide, mauveine behaves unlike
rosaniline, yielding a beautiful colouring matter, which is of a
redder shade, and not bluer as in the latter case. This colouring
matter, called dahlia (patented on 6th November 1863), consists
of a monethylic derivative of mauveine, its hydrochloride being
represented by the formula C 2 7H23(C 2 H5)N 4 HC1. No further
change is effected by ethyl iodide, and it is uncertain whether
the product is a substitution or an addition compound (it may
be remarked here that at times some quantity of a dark, blue-
black, almost insoluble substance containing iodine is also
produced).

1 66 THE BRITISH COAL-TAR INDUSTRY

This dahlia or ethylmauveine was used by the calico printers
and dyers to some extent, though not largely, on account of its
costliness. It is, however, a colouring matter which gives
shades of very considerable stability on exposure to light.

The discovery that the introduction of such radicles as phenyl
or ethyl altered the colour of rosaniline so greatly, made it of
interest to see whether other kinds of hydrocarbon groups could
be introduced to modify its tint. Amongst other products,
brominated turpentine was used, and on heating it with rosaniline
hydrochloride dissolved in methylated spirit or methyl alcohol
under pressure, it was found that a very beautiful purple or
violet colouring matter could be produced ; the process was
patented in 1864, and large quantities of a colouring matter,
known as Britannia violet, were prepared in this manner. At
first it was thought that the hydrocarbon radicle of the brominated
turpentine entered the rosaniline, but it now appears most
probable that the product consisted of methylrosanilines produced
by the action of methyl bromide formed from hydrogen bromide
resulting from the decomposition of the bromo compound.
The colouring matter was more soluble than Hofmann's ethyl
violet, but I could not succeed in crystallising it, and, therefore,
it was not subjected to analysis.

When the base of Britannia violet is acted on by acetyl
chloride, two products are obtained, namely, a violet colouring
matter much bluer in shade than the original violet, and a bluish-
green compound. The base of this latter has a very feeble
affinity for acids, and does not combine with acetic acid, whilst
the base of the violet compound does so freely, and in virtue of
these different properties the two colouring matters are easily
separated. The green dye proved to be of practical value, and
considerable quantities of it were prepared for the calico printers.
It was known as Perkin's green, but after a time it was displaced
by iodine green. It has not hitherto been investigated. For
its manufacture, large quantities of terchloride of phosphorus
were prepared, from which and acetic acid large quantities of
acetyl chloride were made another instance of the use of a
research reagent on the large scale.

The last investigation relating to colouring matters carried out
by Hofmann in this country was that of the very interesting sub-
stance known as quinoline blue, discovered by Greville Williams,
of which the latter gave an account in the Chemical News for

HOFMANN MEMORIAL LECTURE 167

nth October 1860 (p. 219). A beautiful specimen of the
crystallised substance was displayed in the exhibition of 1862
under the name of cyanin. Quinoline blue was a very pure
shade of colour, and, although an expensive product, attempts
were made to introduce it as a dye ; unfortunately, although pro-
duced from bases of remarkable stability, it was very fugitive,
goods dyed with it fading very quickly indeed when exposed to
the light its sensitiveness being so great that on placing it under
a glass positive photograph and exposing to sunlight, after only
a short time a quinoline blue positive picture was produced.

Hofmann separated from quinoline two blue compounds, to
one of which he gave the formula CaoH^g^I, and to the other
the formula C28H 3 5N 2 I. According to later researches, the blue
is a condensation product derived from quinoline amyliodide and
lepidine amyliodide.

C 29 H 35 N 2 I + H 2 O + HI

Quinoline amyl Lepidine amyl Cyanine or diamyl

iodide. iodide. cyanine iodide.

This formula differs from that given by Hofmann to one of
the products he examined by an atom of carbon only.

After I left the Royal College of Chemistry, the researches
on the phosphorus bases in which I had been helping were con-
tinued by Drs Leibius and Holzmann, to whose able assistance
Hofmann refers in one of his papers ; but in carrying out the
part of this work relating to the phosphammonium, phosph-
arsonium, and arsammonium compounds, another assistant was
active, who is referred to by Hofmann in the following words :

" I conclude this memoir with the expression of my best
thanks for the untiring patience with which Mr Peter Griess
has assisted me in the performance of my experiments on the
phosphorus bases. The truly philosophical spirit in which this
talented chemist has accompanied me through the varying
fortunes of this inquiry, will always be one of my pleasing
recollections."

We know how the high opinion thus expressed by Hofmann
of Griess not only lasted, but became enhanced as time went on ;
and although Griess was not one of Hofmann's pupils, I cannot
refrain from thus referring to him here, as several of his most
important early researches on the diazo compounds were made
within the walls of the Royal College of Chemistry, thereby con-
necting this Institution with work which of late years has had

1 68 THE BRITISH COAL-TAR INDUSTRY

such a marvellous influence on the development of the coal-tar
colour industry. But it is not my intention, nor indeed is it
necessary for me, to go into the history of the diazo compounds,
as this has been so very ably done by my friend Caro in his
memoir of Peter Griess, whom he held in such high esteem, and
who was also one of his greatest friends.

Hofmann's departure was not only a cause of regret to those
who had worked under him and to all his friends ; it was a
heavy loss also to the country at large, as no one had ever done
so much for the cause of chemical science in the kingdom as
Hofmann did, nor had anyone exercised to such an extent that
wonderful power he possessed of stimulating the enthusiasm of
his students and of inciting in them a love of chemistry and of
scientific research. His success is especially striking when the
early history of the Royal College of Chemistry is taken into
account especially its financial difficulties, the dissatisfaction of
some of the subscribers, and the want of understanding as to the
value of scientific research shown both by them and the public at
large. When all these circumstances are considered, we cannot
but marvel at the courage and indomitable determination he dis-
played, which enabled him to overcome all difficulties and to per-
severe in maintaining the high standard of teaching he adopted
at the beginning, as well as to continue the prosecution of scientific
research for its own sake.

Notwithstanding the immense amount of work Hofmann
must have had to attend to in connection with the building
and fitting up of the new chemical laboratories of the Frederick
William University of Berlin, which took place during the first
four years after he left England, namely, from May 1865 to
May 1869, no break occurred in his scientific activity, each year
producing accounts of fresh work accomplished. It was not,
however, until 1869 that he published anything fresh in con-
nection with the coal-tar colours, but in this year several com-
munications appeared.

Having found that the production of rosaniline depended
on the presence of two bases, aniline and toluidine, he naturally
carried his investigation of the subject further, and experimented
with xylidine (meta). However, on heating this base with oxidis-
ing agents, either alone or in presence of toluidine, no colouring
matter was obtained ; but when it was heated with pure aniline,
a red was formed, which he called xylidine red, which was supposed

HOFMANN MEMORIAL LECTURE 169

to be a homologue of rosaniline, probably of the composition
C 2 2H 2 5N 3 O. The colour produced on wool and silk by this
dyestuff was almost as bright as that of rosaniline itself (Ber.^ 2,
377). In a second paper relating to this subject, published in
conjunction with Martius (Ber. y 2, 411), an account is given of
similar experiments with an isomer of xylidine, amidoethylbenzene,
which, from the more recent researches of Beilstein and Kilhlberg
(Zeitsch. f. Chem. [2], 5, 524), we now know must have been a
mixture of the ortho and para compounds. No red colouring
matter was formed from this on boiling it with an oxidising
agent, either alone or mixed with toluidine or even with aniline,
thus affording proof of the interesting fact that an ethyl group
cannot take the place of a methyl group in the interaction which
is involved in the production of colouring matters of the rosani-
line class.

After the discovery of mauve and magenta, many experi-
ments were made with a-naphthylamine, as a source of colouring
matter, and a variety of products was obtained and patented ;
but it is unnecessary for me to enter into an account of these
here, as most of them were found to be of no technical value.
I may, however, allude to two naphthalene derivatives which
have proved useful ; the first of these, naphthazarin, was dis-
covered by Roussin in 1861, who thought it was artificial alizarin.
This beautiful substance, which is now known to be a dihydroxy-
/3-naphthoquinone, lay dormant for a long time, but, owing to
the discovery of improved methods of producing it, has of late
come into use for dyeing black on wool. The second was dis-
covered by Martius, and is known as " Martius yellow " or
dinitro-a-naphthol. These were the principal colouring matters
derived from naphthalene known prior to 1867, when Schiendl
discovered the naphthalene red now known by the name of
Magdala red, a substance remarkable for the beautiful fluor-
escence of its solution. The original process for its preparation
consisted in heating naphthylamine, acetic acid, and potassium
nitrite together, and then adding more naphthylamine and again
heating until the desired colouring matter was produced.

Hofmann investigated this red, and assigned to it the formula
C 30 H 21 N 3 (Ber., 1869, 2, 374).

As this colouring matter and the above formula appeared
to be related to an old friend of mine, azodinaphthyldiamine
(amidoazonaphthalene), I made it the subject of experiments,

i yo THE BRITISH COAL-TAR INDUSTRY

and found that it was easily produced on heating amidoazo-
naphthalene with an acid and naphthylamine, an action taking
place which it was thought involved the displacement of an atom
of hydrogen by naphthyl and the formation of ammonia :

C 20 H 15 N 3 + C 10 H 9 N = C 30 H 21 N 3 + NH 3 .

Amidoazo- Magdala red.

naphthalene.

The colouring matter was called azotrinaphthyldiamine (Proc.
Roy. Int., I4th May 1869).

In a second paper, published in July of the same year, on the
nature of naphthalene red, Hofmann confirms my observations
(Ber., 2, 413).

It has since been shown, however, by Julius (Ber., 1886,
19, 1365), that the action which occurs when amidoazo-
naphthalene is treated with naphthylamine is not nearly so
simple as above indicated, and that the formula of the hydro-
chloride of Magdala red is C 30 H2iN 4 Cl, not C 30 H 2 2N 3 C1.

The research on Magdala red led Hofmann to study the
compound produced by the action of aniline on amidoazobenzene,
a substance described by Martius and Griess, but discovered by
Dale and Caro in 1863, and called by them induline. The ex-
amination of this product was afterwards continued by Hofmann
in conjunction with Geyger, under the heading of colouring
matters obtained from aromatic azodiamines, and published in
1872 (Ber., 5, 472). They called this substance azodiphenyl
blue, and showed that its hydrochloride had the formula
C 18 H 16 N 3 C1.

In 1869 Hofmann also continued his researches on chrys-
aniline, studying the action of methyl and ethyl iodide on the
base ; he obtained trimethyl and triethyl substitution products
(Ber., 2, 378).

In preparing Hofmann violet, it was found that on precipi-
tating the colouring matter from its aqueous solution by means
of sodium chloride, a certain quantity of a bluish-green product
remained in solution which could not be separated (though im-
proved in colour) by the addition of sodium carbonate ; this was
precipitated by means of picric acid, and as it proved to be a
valuable green dye, it, after a time, was supplied in small
quantities to dyers under the name of iodine green. It was then
found by J. Keisser (French patent, i8th April 1866) that the
colouring matter could be obtained in much larger quantities by

HOFMANN MEMORIAL LECTURE 171

methylating rosaniline, dissolved in methyl alcohol, with methyl
iodide, the operation being completed at a comparatively low
temperature, and eventually it was obtained in a pure crystallised
state. This substance being evidently related to the methyl-
rosanilines, Hofmann was naturally interested in it, and with
Girard undertook its investigation (Ber., 2, 440).

The results they obtained, on analysing the iodo compound,
led them to represent it by the formula

Cao^ie I >j
(CH 8 ) 8 / JN

f CH 8 I.
CH.I.H0.

They found that this compound decomposes when heated at
the temperature of boiling water for a few hours, and instantly at
130 150 C., becoming changed into a violet colouring matter ;
in fact, it behaves like an ammonium or addition product. As
the complicated history of the methyl and ethyl derivatives
developed, it was found that the formula above given required
to be modified to some extent ; but this is in no way surprising,
as it is practically impossible by analysis alone to arrive at a true
conclusion as to the constitution of a compound of such high
molecular weight, so unstable and so difficult to obtain pure.

Another green dyestuff to which Hofmann directed his
attention at this time was aldehyde green, produced by the action
of aldehyde on rosaniline in presence of sulphuric acid, whereby
a blue colouring matter is formed, which is transformed into
the green by the action of an aqueous solution of sodium thio-
sulphate. Lauth, apparently, was the first to produce the blue
compound, in 1861, by subjecting a solution of rosaniline in
alcohol, methyl alcohol, acetic acid, or acetone to the action of
zinc chloride and other metallic salts, but the conversion of the blue
into the green was accomplished by Cherpin in 1862. This was
the first aniline green dye discovered (emeraldine, which was of
no value, excepted), and was much used. Hofmann showed that
aldehyde green contained sulphur, and assigned to it the com-
position indicated by the formula C22H27N 3 S 2 O, representing
its formation by the following equation,

C 20 H 19 N 3 + C 2 H 4 O + 2H 2 S = C 22 H 27 N 8 S 2 O

(Bcr., 1870,3,761).

The next researches it will be most convenient to refer to,
though not quite the next as to date, are those on the methyl

172 THE BRITISH COAL-TAR INDUSTRY

violets ; but, before considering these it may be mentioned that,
in continuation of his researches on rosaniline derivatives,
Hofmann, in 1873 (Ber., 6, 263), examined the violet obtained
by Hobrecker by the action of benzyl chloride and methyl iodide
on a solution of rosaniline in methyl alcohol, assigning to it the
formula C 2 oH 16 (C 7 H 7 ) 3 N 3 CH 3 I.

Until long after the commencement of the coal-tar colour
industry, chemists and experimenters directed their attention
chiefly to aniline as a source of colouring matter ; but in 1861
Lauth made some experiments on the product Hofmann obtained
by acting with methyl iodide on aniline, which he described as
methylaniline (Jour. Chem. Soc., 1851, 3, 296), but which recent
researches have shown is a mixture of methylaniline and di-
methylaniline, and by oxidising this he obtained violet colouring
matters. Writing of these in 1867, Lauth says (Laboratory,
1867, 138), "The violets obtained from methylaniline possess
a richness and purity which leave nothing to be desired. . . .
Nevertheless, they were not adopted by manufacturers, who,
indeed, at the time mentioned (1861) attached less importance
to the beauty of a colour than to its permanence. In this latter
respect the methylaniline violets do not excel, and, consequently,
dyers would have nothing to do with them. Gradually, how-
ever, people have become accustomed to colours which fade on
exposure to the solar rays. . . . Accordingly, two years after the
experiment made by myself, Dr Hofmann succeeded in introduc-
ing these results."

These remarks confirm those already made in reference to the
gradual change in public opinion which led to the disregard of
permanency in favour of brilliancy of colour.

Lauth further remarks that Hofmann's method of producing
these colouring matters is the inverse of that proposed by him ; the
aniline being first converted into rosaniline and then methylated,
whilst in his case this operation is first performed on the aniline.

It would, however, not have been practicable to carry out
this process if the aniline had to be methylated with methyl
iodide, because the base thus prepared would be too expensive
to use as the raw material for the preparation of colouring
matters. On account of the success of the Hofmann violet,
experiments were made in France with the object of preparing
methylaniline by a different and more economical process, so as
to commercially produce Lauth's violet, and this was at that time

HOFMANN MEMORIAL LECTURE 173

considered especially desirable by some manufacturers, because
the production of rosaniline in France was the monopoly of one
house, and, therefore, derivatives of this colouring matter could
not be economically made by others.

Eventually a successful process was discovered by M. Bardy,
chemist to the firm of Poirrier & Chapat, which consists in
heating a mixture of aniline hydrochloride and methyl alcohol
in a closed vessel to a high temperature. As is now well known,
though not at first recognised, this process yields a mixture of
mono- and di-methylaniline, consisting chiefly of the latter.
Large quantities of methylated aniline were soon produced by
this process, and used in the preparation of a violet colouring
matter which was manufactured by Messrs Poirrier & Chapat,
and called by them violet de Paris ; a large block of this,
weighing about 150 kilos, was exhibited in the Paris Exhibi-
tion of 1867. The question then arose as to whether violet de
Paris was identical or isomeric with methylrosaniline violet.
Lauth considered that it was isomeric, and remarks : u Hofmann
violets consist of methylated and ethylated rosaniline, and
rosaniline is derived from a molecule of aniline and two molecules
of toluidine. The violet de Paris, on the contrary, is produced
from pure aniline free from toluidine, transformed into methyl-
aniline, which is isomeric with toluidine. This methylaniline
when oxidised is converted into the violet, which may have a
composition analogous to that of methylated rosaniline, but must
differ from the latter in the same manner as methylaniline differs
from toluidine."

Hofmann, being naturally interested in the relationship of
these colouring matters, investigated the subject, and published
his results in 1873 (for., 6, 352). He first studied the
conditions under which the colouring matter could be formed,
showing that violet could be produced from pure dimethylaniline
obtained by the distillation of trimethylammonium hydrate ; he
also came to the conclusion from the examination of the colouring
matter that it was a methylchlorhydrate of trimethylrosaniline :

C 20 H 16 (CH 8 ) 3 N 3 .CH 3 .C1,
the base being

C 20 H 16 (CH 3 ) 3 N 3 .CH 3 .OH.

He prepared iodine green by methylating this compound ;
also its leuco compound.

174 THE BRITISH COAL-TAR INDUSTRY

This research must have been a very difficult and laborious
piece of work, and although Hofmann's views as to the constitu-
tion of the dimethylaniline violet are not those now accepted,
the accuracy of his work has not been impugned.

The long controversy which arose, soon after the time when
Hofmann published his constitutional formula of rosaniline, as
to the constitution of this colouring matter, belongs to another
chapter, and need not be referred to here.

Mention has already been made of the process for methylating
aniline discovered by Bardy, which consisted in heating this base
with hydrochloric acid and methyl alcohol. In 1871 Hofmann
and Martius (Ber., 4, 742) made some experiments in reference
to this method, working at higher temperatures than those usually
employed (28o-3OO C.), and continuing the heating for a con-
siderable time ; in this way they obtained, besides methyl, and
dimethylaniline, a quantity of basic oil of higher boiling-point,
which eventually proved to be a complex mixture of methylated
homologues of dimethylaniline, the products of an intramolecular
change or atomic wandering.

These remarkable researches, like so many other purely
scientific discoveries, ere many years had passed, were found to
be of technical value in connection with the coal-tar colour in-
dustry, the cumidine that is so extensively used in the preparation
of some of the diazo colours being made by the method of Hof-
mann and Martius by heating xylidine with hydrochloric acid and
methyl alcohol to a high temperature, about 300 C.

Reverting once more to the early days of the coal-tar colour
industry, I may now mention that the liquors from which mauve
was precipitated were found to contain a red colouring matter
which I succeeded in separating, although the amount obtainable
was very small. This proved to be a beautiful dye producing
crimson-red shades on silk. It was afterwards discovered that
it could be produced by the oxidation of mauveine, and it was
prepared in considerable quantity in this way, but was a very
expensive product, and therefore not very largely used. This
dyestuff was known first as "aniline pink," and afterwards as
" safranine." In 1865 a colouring matter having the properties
of safranine was produced without the use of mauveine by F.
Duprey, by heating commercial aniline dissolved in acetic acid
with lead nitrate. It was then obtained by acting on commercial
aniline with nitrous acid and oxidising the mixture with arsenic

HOFMANN MEMORIAL LECTURE 175

acid. The colouring matter prepared in this way was examined
by Hofmann and Geyger (Ber., 1872, 5, 531). They found
it to be a base forming crystalline salts, among others a hydro-
chloride having the composition C^i^iN^CL As they found
that it could not be produced from either aniline or paratoluidine,
or a mixture of the two, but from orthotoluidine, they regarded
it as a toluidine derivative. They also observed that the formula
above given differs from that of mauveine by C 6 H 4 , making it
appear possible that mauveine was phenylsafranine. In the
course of an investigation of the safranine, obtained by the
oxidation of mauveine, of which I published an account some
time after this (Jour. Chem. Soc., 1879, 35, 728), this substance
was shown to form a hydrochloride represented by the formula
C 20 H 18 N 4 , which differs from that of the substance examined by
Hofmann and Geyger by CH 2 . On examining a commercial
product manufactured by Messrs Guinon & Co., of Lyons, from
commercial aniline, both substances were found to be present,
showing that two " safranines " existed, and I then also showed
that probably a third was formed by the oxidation of pseudo-
mauveine.

The formula of the safranine hydrochloride obtained from
mauveine will be seen from the above to differ from mauveine
by C 7 H 6 , so that the relationship of these substances is probably
not of so simple a character as Hofmann and Geyger supposed,
though, of course, C 7 H 6 may simply mean displacement of
hydrogen by tolyl. No doubt a great similarity exists between
them, one proof of which is that their behaviour with sulphuric
acid is analogous. This applies both to those referred to above
and to the third compound since discovered.

In 1875 Hofmann made an examination of eosin (Ber., 8, 62),
and thus disclosed to the world an important manufacturing
secret, proving to demonstration the impossibility in these days
of long hiding from chemists the nature of any substance, how-
ever complex. Eosin, as is well known, was the first representa-
tive of a new class of colouring matters which has since become
of great importance.

Chrysoidine, which may fairly be termed the parent of an
even more important class of colouring matters, the azo dyes,
the introduction of which marks a new era in this branch of
chemistry, was investigated and publicly proclaimed by Hofmann
in 1877 (Ber., 10, 213).

176 THE BRITISH COAL-TAR INDUSTRY

The colouring matter to which he next directed his attention
was pittacal, also called euppitonic acid, the interesting compound
discovered by Reichenbach, as far back as 1835, produced from
wood tar. Hofmann (Ber., 1878, 11, 1655 ; 1879, 12, 1371 and
2216) was led to regard this substance as hexamethoxyrosolic
acid, C 19 H 8 (OCH 3 ) 6 O 3 ; on treating it with ammonia, he
obtained a beautiful blue dyestuff, thus,

C 25 H 26 9 + 3 H 3 N = C 25 H 31 N 3 6 + 2<DH 2 ,
which he regarded as hexamethoxypararosaniline,

C 19 H 13 (OCH 3 ) 6 N 3 0.

He then made the interesting discovery that the formation
of pittacal, or euppitonic acid, from dimethylpyrogallate and
dimethyl-methylpyrogallate took place in a manner analogous
to that in which pararosaniline was formed, thus,

2 . C 6 H 7 N + C 7 H 9 N = C 19 H 17 N 3 + H3 2 .

Aniline. Toluidine. Pararosaniline.

2 C 8 H 10 O 3 + C 9 H 12 O 3 = C 25 H 26 O 9 + 3H 2 ,

Dimethyl- Dimethyl-methyl- Pittacol or

pyrogallate. pyrogallate. euppitonic acid.

a comparison which is of considerable interest.

Hofmann's last research in connection with the coal-tar
colour industry was made as late as 1887, and related to the
quinoline red prepared by Jacobson, in 1882, from coal-tar
quinoline, benzotrichloride, and zinc chloride. Hofmann, how-
ever, found that a better yield of colouring matter, either
identical or isomeric with Jacobson's, is obtained by using a
mixture of isoquinoline and quinaldine. Like quinoline blue
or cyanine, the colour is not a fast one, which as previously
mentioned, is remarkable, considering the stability of quinoline
itself. It is a somewhat remarkable coincidence that this should
have been the last research Hofmann made on the coal-tar
colours, as quinoline (or leucoline) was one of the two substances
he gave an account of in his first investigation published in 1843,
when thirty years of age.

Excepting what is said of pittacal, and the brief reference to
eosin and chrysoidine, the foregoing account has reference only
to what may be termed aniline colours, the great chapter dealing
with the history of technical chemistry, with which Hofmann's
name is indissolubly linked.

HOFMANN MEMORIAL LECTURE 177

An entirely new chapter in coal-tar chemistry opens in 1868,
when Graebe and Liebermann (in connection with their re-
searches on quinones) made their great discovery of the artificial
formation of alizarin from anthracene. They patented their
process in Germany in October, and in this country on i8th
December of that year. Their process, it is well known, con-
sisted in producing dibromanthraquinone, either by brominating
anthraquinone in sealed tubes, or by oxidising tetrabrom-
anthracene, and subsequently displacing bromine by hydroxyl,
by fusion with alkali.

This discovery for the first time of a method of obtaining
a vegetable colouring matter artificially was, however, as it stood,
of no practical value, as such a process could not be carried out
on a large scale.

But why should this be mentioned here ? It may seem that
any reference to the alizarin industry is out of place in a notice
designed to elucidate Hofmann's influence on the development
of our knowledge of products derived from coal-tar, as he
apparently never took any part in the investigation of anthracene
derivatives. Yet it is to his influence that I can trace back my
interest in the subject, for, as mentioned early in this account,
the very first subject in research which he suggested to me was
to prepare a nitro compound and a base from anthracene. In
the course of this work I not only became thoroughly acquainted
with this hydrocarbon, but also prepared anthraquinone and
other derivatives of it, and consequently was, perhaps, more
fully prepared than any other chemist of the day to appreciate
the discovery of the relationship of alizarin to anthracene, and
was naturally impelled at once to attempt to adapt it to practical
requirements. It is more than probable that I should have paid
but ordinary attention to Graebe and Liebermann's work had I
not possessed an early attachment to anthracene, and I am glad
to recognise that I owe this to the knowledge and insight of my
great master.

Being aware of the importance of alizarin as a colouring
matter, and having some quantity of anthracene and anthra-
quinone left over from my experiments at the Royal College
of Chemistry, I commenced to experiment on the formation of
this substance, with the object of finding a process by which
bromine might be dispensed with.

I knew of the remarkable stability of anthraquinone : that

178 THE BRITISH COAL-TAR INDUSTRY

it could be crystallised from concentrated sulphuric acid without
undergoing change, and that in making a combustion of it, if
the operation were at all hurried, part of the anthraquinone
would pass through the heated tube, and condense at the cool
end unaltered.

Moreover, not long before I commenced to work at the
artificial formation of alizarin, namely, in 1867, Wilrtz and
Kekule had shown that when benezenesulphonic acid was heated
with potassium hydrate, it gave a phenate and sulphite ; and
Dusart had also found that naphthalenedisulphonic acid was in
like manner converted into a dihydroxynaphthalene ; so that it
appeared probable that if a disulphonic acid of anthraquinone
could be obtained, it would be possible to convert it by the
new reaction into alizarin.

Anthraquinone was therefore heated with oil of vitriol more
and more strongly, until the boiling-point was nearly reached, as
I was determined either to obtain a sulphonic acid or destroy the
anthraquinone ; and at last it was found that the anthraquinone
had disappeared, yielding a product which was soluble in water.
After the excess of sulphuric acid had been removed in the usual
way with barium carbonate, the product was fused with caustic
alkali, and to my delight it changed first to violet, and then
became black from the intensity of its colour. On dissolving
the melt, a beautiful purple solution was obtained, which gave a
yellow precipitate when acidified, and on examination this was
found to dye mordanted cloth like garancine.

On the 2oth of May (1869) I sent dyed patterns to my friend
Mr Robert Hogg, of Glasgow, who had a very large experience
in reference to madder and garancine, and also of the coal-tar
colours from the days of the mauve dye, whose opinion I valued
very much in all practical matters connected with dye-stuffs,
especially from a commercial point of view, and he was very
favourably impressed with the results I had obtained. This
process, however, was not patented until 26th June. (About
the same time as I discovered this process, Graebe, Liebermann,
and Caro quite independently arrived at the same result in
Germany.) This process has proved the most permanently
important one yet discovered, and is the one still universally
used. I was also fortunate enough to discover a second process,
which was of great value in the early days of the industry, but is
not in use now so far as I know. It consisted in the use of

HOFMANN MEMORIAL LECTURE 179

dichloranthracene as the starting-point, instead of anthraquinone.
This substance was found to readily afford a sulphonic acid,
which could be easily changed into anthraquinonesulphonic acid,
either by oxidising its solution with manganese dioxide or more
simply by heating it with sulphuric acid. This process was
patented in November 1869.

After discovering processes by which artificial alizarin could
be produced, the technical value of the artificially prepared dye-
stuff had to be ascertained. Experiments were soon made by
the calico printers, as no new processes had to be discovered for
the application of this colouring matter, those in use for madder
and garancine being suitable. Turkey-red dyers also experi-
mented with it, but some were not so successful as others, for
reasons easily understood afterwards, when the properties of
anthrapurpurin, which it contained, were better known.

The subject of price, however, was the important question,
because this product had to compete with those already in the
market, namely, madder and garancine, and therefore high prices
could not be obtained as in the case of a new dye.

Before this could be settled, the first thing necessary was to
get a supply of anthracene. This substance was not at this date
separated by the tar distillers, there being no use for it ; many of
them, in fact, knew nothing of its existence, and the question as
to whether it could be obtained in sufficient quantity and at a
sufficiently low price had to be settled.

But experiments I had made on the small scale, on the dis-
tillation of soft pitch, at the Royal College of Chemistry, gave
me confidence, and my brother and I entered into the matter
with great energy. 1 At first we prepared anthracene by distil-
ling pitch ourselves, and thought of using this as a source of this
hydrocarbon on an extensive scale, as we felt it was capable of
yielding a considerable supply. We knew, however, that it
could also be obtained from the last runnings of the tar stills,
from which it crystallised on cooling. My brother, therefore,
visited nearly all the tar works in the kingdom, and showed the
distillers how to separate the anthracene, promising to take all
they could make, and in this way a sufficient and rapidly increas-
ing supply for our requirements was soon obtained of all sorts of
qualities, some being not much thicker than pea soup, from the

1 My father, to whose great kindness I was so much indebted, died in
1864, so that our firm then consisted only of my brother and myself.

i8o THE BRITISH COAL-TAR INDUSTRY

imperfect way in which it was drained. Very few tar distillers
in those days had hydraulic presses, such as are now used, with
which they could free the solid from the excess of oil. The
value of the anthracene was estimated by washing with carbon
bisulphide, afterwards alcohol was used, but for our own purposes
we all along used an anthraquinone test. This method was
afterwards worked out more perfectly on the Continent, and made
a practical test for both the buyer and seller ; but at the time I
am writing of tar distillers were not sufficiently educated in such
matters to use any but very simple tests.

The purification of the anthracene sufficiently for our purpose
had then to be worked out, and in doing this I found out a
curious fact, namely, that when distilled with caustic potash it
was much improved in quality considerably more so than when
distilled either alone or with caustic soda. And potash-distilled
anthracene was especially necessary when dichloranthracene had
to be prepared, as it yielded a well-crystallised, easily purified
product, whereas anthracene which had been distilled, either alone
or with caustic soda, gave a badly crystallised, sticky product,
which was very difficult to purify.

On examining into the action of caustic potash on anthracene,
it was found that if, after the anthracene had been distilled off,
the residue was freed from alkali by washing, and then distilled,
a substance very like anthracene was obtained, which Graebe
subsequently found to be the nitrogenous compound now known
as carbazol. It is by means of caustic potash that this substance
is now separated from crude anthracene, and the process is still
used to a large extent to improve the quality of anthracene. All
the anthracene we used at Greenford Green was treated in this
manner.

The purification of the anthraquinone was at first effected by
sublimation, followed by crystallisation. A good deal of difficulty
was experienced in the conversion of this substance into its
sulphonic acid, however, and at the high temperature at which
combination took place, the formation of steam from the water
produced at the same time led to considerable quantities of the
anthraquinone becoming sublimed, which, although not lost, yet
was a source of trouble in various ways. The means of over-
coming this difficulty was to use fuming sulphuric acid, with
which anthraquinone combined at a much lower temperature, but
the only acid of the kind then made was the old-fashioned Nord-

HOFMANN MEMORIAL LECTURE 181

hausen acid. We imported a quantity of this, and, of course,
found it to work satisfactorily, but the difficulties and expense
connected with the carriage and transport of this substance on
account of its dangerous nature supplied as it then was in large
earthenware bottles made it unsuitable for use in this country.

The artificial alizarin we first made was produced by the
anthraquinone process, the method still used for its manufacture,
but the difficulty in preparing the sulphonic acid in those early
days just referred to caused us to turn our attention to the second
process I had discovered, in which dichloranthracene was used.
After finding out the best way of preparing the substance, our
difficulties in reference to the sulphonic acid vanished, as dichloran-
thracene dissolves easily in hot ordinary oil of vitriol, producing
dichloranthracenedisulphonic acid ; on continued heating this acid
oxidises, hydrogen chloride and sulphur dioxide being evolved
and anthraquinonedisulphonic acid formed. Without this process,
the manufacture of artificial alizarin in this country could not
have been carried on with much success in the early days of its
manufacture.

The conversion of the anthraquinonesulphonic acids into
colouring matter by treatment with caustic alkali at a high
temperature at first presented many difficulties when carried out
on the large scale. Our earliest experiments were made by heat-
ing the mixture in iron trays in a large air bath. Mixtures of
caustic potash and caustic soda were also experimented with in-
stead of caustic soda alone. Then the mixture was placed in a
revolving cylinder, heated in an air bath, small cannon balls being
put into the cylinder to mix the product. But all these methods
were only partially successful, the percentage of colouring matter
produced not being so high as it should have been. At last heat-
ing in a very strong iron boiler under pressure was resorted to,
and by adopting this method which is now that universally
used we obtained a satisfactory result.

From the experiments we made in 1869 we felt pretty con-
fident that artificial alizarin could be made at a price to compete
with madder and garancine, and before the end of the year we
had produced i ton of this colouring matter in the form of paste,
in 1870 40 tons, and in 1871 220 tons, and so on in increasing
quantities year by year.

The colouring matter produced from dichloranthracene was
chiefly anthrapurpurin containing a little flavopurpurin. Theo-

1 82 THE BRITISH COAL-TAR INDUSTRY

retically it should have consisted of these products only, but
owing to the occurrence of a secondary action, which I need not
refer to here (see Lectures Soc. Arts^ 3Oth May 1879), ^ a ^ so con ~
tained alizarin, which we sometimes separated when required for
dyeing purples. This colouring matter yielded a shade of colour
which answered most of the requirements of the consumers for
some time, as it was chiefly used by the Turkey-red dyers, and
the supply being limited, it was often used in combination with
garancine, as in this way more brilliant reds could be obtained
than when using garancine alone, though, of course, the use of
the artificial colouring matter alone yielded still clearer and more
fiery shades.

Dichloranthracene was afterwards found to yield a mono-
sulphonic acid when treated with sulphuric acid, provided the
temperature was kept low and the amount of acid limited ; and
when oxidised with manganese peroxide or other oxidising agent,
this yielded anthraquinonemonosulphonic acid, from which
alizarin alone could be obtained. But the properties of di-
chloranthracene-monosulphonic acid were such, and the technical
difficulties of carrying out the process so considerable, that it was
never used very successfully. Moreover, by this time, fuming
sulphuric acid had come into use, and anthraquinonemono-
sulphonic acid could be more readily produced directly from
anthraquinone. As we had been successful in producing artificial
alizarin, others did not run much risk in following our lead ; yet,
up to the end of 1870, the Greenford Green Works were the
only ones producing artificial alizarin. German manufacturers
then began to make it, first in small and then in increasing
quantities, but until the end of 1873 there was scarcely any com-
petition with our colouring matter in this country.

From the foregoing, it is seen that, as in the case of the
aniline colours, all the pioneering work connected with the
foundation and establishment of this branch of the coal-tar colour
industry was done in this country.

For the due development of this industry, it was necessary
not only to attend to technical processes, but also to carry on
scientific research in connection with it. Early in 1870, I had
the honour of bringing before this Society an account of some
experiments on the formation of the colouring matter obtained
from the sulphonic acids of anthraquinone, showing that it
contained alizarin possessed of both the chemical and optical

HOFMANN MEMORIAL LECTURE 183

properties of that obtained from madder-root. At the same
time, attention was directed to the existence of a second colour-
ing matter, yielding reds more scarlet and purples of a bluer
shade than alizarin (Jour. Chem. Soc., 1 870, 23, 133). This second
colouring matter was afterwards made the subject of further
investigation, and shown to be an isomer of purpurin ; it was
therefore called anthrapurpurin (Jour. Chem. Soc., 1872, 25, 659,
and 1873, 26, 425). Dichlor- and dibrom- anthracene and their
disulphonic acids, etc., were also investigated. Anthraflavic acid,
discovered by Schunck in some secondary products sent to him
from my works, was made the subject of two researches ; in
the first of these, this compound was shown to be an isomer of
alizarin, and not to contain C 15 as supposed by its discoverer.
In the second, the sublimed acid was examined and found to be
identical with the unsublimed ; it was also shown that when
fused with alkali it did not yield alizarin, as stated by Schunck,
but a colouring matter yielding orange-red colours with alumina
mordants. This, Schunck and Roemer, some time afterwards
showed to be another isomer of purpurin which was named by
them flavopurpurin.

In this investigation, anthraflavic acid was found to yield a
diacetyl and dibenzoyl derivative, which was evidence that it con-
tained two hydroxyl groups like alizarin (Jour. Chem. Soc., 1873,
26, 19). Later on, an investigation was made on the formation
of anthrapurpurin, proving that, as in the case of flavopurpurin,
the formation of the colouring matter from the disulphonic acid
of anthraquinone is preceded by that of a dihydroxy derivative,
also an isomer of alizarin, now known as isoanthraflavic acid,
which, when heated with caustic alkali, is partially oxidised into
anthrapurpurin and partially reduced (Jour. Chem. Soc. y 1876,1. 29,
851). Besides these, the formation of bromalizarin (Jour. Chem.
Soc. y 1874, 27, 401), of /3-nitroalizarin (Jour. Chem. Soc., 1876, ii.
30, 578), of anthrapurpuramide (Jour. Chem. Soc., 1878, 33, 216),
and of the dibromanthraquinones discovered by Graebe and Lieber-
mann and the colouring matters obtainable from them, were
investigated (Jour. Chem. Soc. y 1880, 37, 554). Much work has
also been done in reference to this industry by Graebe and
Liebermann and other investigators.

The manufacture of artificial alizarin in Germany has been
almost entirely confined to the anthraquinone process, fuming
sulphuric acid being used in the preparation of the sulphonic

1 84 THE BRITISH COAL-TAR INDUSTRY

acids. For this purpose very strong acid, containing about
40 per cent, of anhydride, was made from Nordhausen acid,
and used until the process of making sulphuric anhydride by
decomposing sulphuric acid into sulphurous oxide, oxygen, and
water, and recombining the two former, was introduced.

After being engaged in the coal-tar colour industry for
eighteen years, my connection with it, technically, came to an
end in 1874, when the alizarin industry had been well established
and was rapidly extending.

On looking back over the period, it is of interest to see the
wonderful progress the industry had made up to that time a
progress which was going on by leaps and bounds. I have no
statistics connected with the precise period, but four years after-
wards, namely in 1878 with the kind assistance of Dr Caro
an estimate of the value of the colours produced during that
year was obtained, at a time when the industry had just passed
its majority and was twenty-two years old. The sum amounted
to 3,150,000. (See Jour. Soc. Arts^ 3Oth May 1879.) Of its
present position, it is very difficult to speak. Certainly its pro-
gress has been very great since 1878 ; but chiefly owing to the
scientific skill bestowed upon the production of the colouring
matters, their cost has been greatly dimished, so that I under-
stand rosaniline hydrochloride, which once was worth about
3, 35. per ounce, may now be purchased at 2s. 9d. per lb., and
aniline at less than 6d. per lb. . . .

During the early days of the coal-tar colour industry, the
complaint was made that the prosecution of purely scientific
chemistry was being injured by its influence, as chemists were
everywhere experimenting with aniline and other products, with
objects of a more selfish than scientific character. It is probable
that there was some truth in this for a time, but it was not long
before a welcome change set in, and the work carried on in
relation to this industry was soon conducted in a scientific spirit,
even when the result sought for was expected to be of technical,
as well as where it was expected to be of scientific, value. But
the amount of work carried on from the latter point of view
increased more and more, as interesting questions connected with
the colouring matters and the methods by which they were pro-
duced presented themselves to chemists, and now if we look
back and consider what has been accomplished, we find that
this industry has directly and indirectly had a most marvellous

HOFMANN MEMORIAL LECTURE 185

influence on the advancement of chemical science, especially that
part of it relating to the aromatic series of compounds. No
other industry in existence can at all be compared with it from
this point of view. This has arisen from a variety of circum-
stances, one of which is that it has not been carried on by the
rule-of-thumb method which has been so common in other cases.
Again, as it has utilised the discoveries of chemists, it has
handed back to them in return new products which they could
not have obtained without its aid, and these have served as
materials for still more advanced work : this kind of exchange,
indeed, has been going on so repeatedly, that products formerly
of the rarest and most complex character are now quite common
substances in the coal-tar colour works.

We knew that aniline was at first a rare substance, and when
it was afterwards proposed to use ethyl and methyl iodides in
the preparation of ordinary dyestuffs, it seemed incredible that
such substances could be introduced for such a purpose as
already mentioned, substances which were but rarely met with
even in chemical laboratories : but what are these compared with
the substances now in use ? their names would be too numerous
to mention. One of the most striking facts connected with this
industry is the remarkably rapid way in which it has utilised
new discoveries which have often been no sooner made than they
have been practically applied. This do doubt arises from the
fact that an ever-increasing army of highly trained and highly
gifted chemists are engaged in the industry, especially on the
Continent, provided with splendid laboratories, libraries of
scientific works, and all the most advanced appliances required
in scientific research ; and the members of this army are not
only making discoveries themselves and applying them, but are
always on the alert to make the discoveries of others subservient
to the industry.

As I have already mentioned, when this industry was first
instituted, organic chemistry was comparatively in its infancy,
especially if we regard it from our present standpoint. Kekul
had not then brought forward his remarkable benzene theory,
and after he had done so its bearings required much elucidation
before their importance was well understood. Only solid tolui-
dine was known, orthotoluidine not having been discovered,
although it was constantly present in the high boiling aniline
used in making rosaniline ; but now the facts connected with

1 86 THE BRITISH COAL-TAR INDUSTRY

the ortho-, meta-, and para-position in substances containing the
benzene nucleus, or of the a- and ^-positions in the naphthalene
series, are among the most important to be considered in the
manufacture of colouring matters ; in fact, this industry has done
more to accentuate the importance and character of these positions
than any other kind of experimental work.

Although at the commencement of the industry a good deal
of work of a purely experimental character had to be done,
nevertheless, from the first it was carried out on scientific lines,
and this characteristic increased very rapidly, as is seen by the
early date at which mauve and magenta were obtained in the
pure crystallised condition : it was at this period, as previously
stated, that Hofmann commenced his researches on rosaniline
and its derivatives, and on other colouring matters, and these
researches, taken with those of others, bear out the observations
which have just been made. In looking over the work of
Hofmann in this field, all who have had experience in the investi-
gation of the subjects he undertook must realise that they pre-
sented no ordinary difficulties, especially as for some time he
had nothing to guide him in his conclusions but the analytical
results. In the early days of organic chemistry, it is well known
that on finding colouring matters in the products they were
examining, chemists usually regarded them as impurities, and
the use of animal charcoal and other means were resorted to for
the purpose of getting rid of them ; and those who undertook
to do the examination of colouring matters themselves were
considered as bold men, and not likely to get much result from
their labour. Doubtless, there was much truth in this. Hof-
mann, however, was a bold man, and not one to be daunted, but
rather inspired, by difficulties ; and from his results we see how
great his success was in this department of chemistry, some of
his work proving to be of direct practical value, whilst other
parts possessed important bearings both on the practical and
scientific development of this subject. His researches on colour-
ing matters extended over a quarter of a century, commencing
in 1862 with rosaniline, and ending in 1887 with quinoline red ;
and during that period there were but few years in which he did
not produce one or more investigations, either related to colour-
ing matters or the products connected with their production.

It will be obvious from what has been said, how Hofmann 's
early work after that of Faraday, Unverdorben, Runge,

HOFMANN MEMORIAL LECTURE 187

Fritsche, Mitscherlich, and Zinin continued to pave the way
for the introduction of the coal-tar colour industry, also how the
important influence he exercised on the training of his students
led in the same direction. I especially refer to Mansfield, who
did such valuable work on coal-tar, and Nicholson, whose chemi-
cal education under Hofmann was such an important preparation
for the work he undertook in after years on rosaniline and its
derivatives ; and if I may speak for myself, I can only say how
much I owe to Hofmann's training, which fitted me to carry out
the work which fell to my lot in connection with the introduction
and development of this industry. Then if we further consider
the importance of the beautiful researches Hofmann made, some
of which yielded practical results, throwing fresh light on the
nature of the colouring matters and products related to them
which were obtained as time went on, some idea may be formed
of the contributions made by Hofmann and his school to the
coal-tar colour industry.

And yet we must bear in mind that his work in this depart-
ment of chemistry represents but a small part of all that he
accomplished indeed, the amount of scientific work he did was
something marvellous.

X.: igoi
THE SYNTHESIS OF INDIGO

BY PROFESSOR R. MELDOLA, F.R.S., F.I.C.

(Journal of the Society of Arts^ 1901, p. 397)

THIS paper discusses the various synthetical processes which have been
used for the production of indigo. The latter portion of the paper is
quoted in the article on " The Indigo Crisis " : see p. 219.

188

XL: 1901

THE RELATIVE PROGRESS

OF THE COAL-TAR COLOUR INDUSTRY IN

ENGLAND AND GERMANY DURING THE

PAST FIFTEEN YEARS

BY ARTHUR G. GREEN, F.I.C., F.C.S.
(Paper read before the British Association, Section B, Glasgow, 1901)

THE coal-tar colour manufacture has well been called the flower
of the chemical industries. Although in absolute money value of
its products not equalling some other branches of industrial
chemistry, it represents the highest development of applied
chemical research and chemical engineering, and may well be
taken as the pulse of the whole chemical trade. Indeed, a
country which allows the most scientific branch of chemical
industry to languish cannot expect to maintain pre-eminence for
long in any simpler branch of chemical manufacture ; since the
skill trained for attacking the difficult problems of organic
chemistry is certain sooner or later to be brought to bear on the
simpler questions presented in the manufacture of so-called
" heavy " chemicals (acids, alkalies, bleach, salts, etc.), and processes
hitherto often left to the supervision of foremen will be taken in
hand by educated chemists, with consequent improvement in
methods of manufacture, better yields, purer products, and cheaper
production. The importance of the coal-tar industry cannot
therefore be estimated alone by the value of its products, for it
exerts a widespread effect upon all other branches of chemical manu-
facture, from many of which it draws its supplies of raw material.
As a pregnant example of this influence, especially noticeable during
the last decade, I may mention the revolution which is taking

189

1 90 THE BRITISH COAL-TAR INDUSTRY

place in the manufacture of sulphuric acid, that most important
product of the " heavy " chemical trade. A strong demand had
arisen in the colour industry for a large and cheap supply of
sulphuric anhydride, chiefly in connection with the manufacture
of alizarin colours and of artificial indigo. With the object of
satisfying their own requirements in this respect, the Baden
Aniline and Soda Works of Ludwigshafen devoted much time
and research to the problem of improving the catalytic process
usually known by the name of Winckler, a modification of which
process had been worked in this country by Squire Chapman and
Messel since 1876. This endeavour was attended with such
success that by means of the process and plant which they finally
evolved they were enabled to produce sulphuric anhydride so
cheaply that not only could it be used as such for a large variety
of purposes, but by combination with water afforded a profitable
source of sulphuric acid. This new method of manufacturing
sulphuric acid is, for concentrated acid at least, cheaper than the
chamber process ; and since the product is absolutely free from
arsenic, and can be produced at any desired concentration, it
seems likely to supplant eventually the time-honoured method
of manufacture.

Besides exerting this influence upon the inorganic chemical
manufactures, the coal-tar industry has given birth during recent
years to several important daughter industries. The manufacture
of synthetic medicinal agents, artificial perfumes, sweetening
materials, antitoxines, nutritives, and photographic developers
are all outgrowths of the coal-tar industry, and in great part still
remain attached to the colour works where they originated. Of
these subsidiary industries the most important is the manufacture
of synthetic medicinal preparations, which has already attained to
large proportions, and bids fair to revolutionise medical science.
The requirements of the coal-tar industry have further led to
great advances in the design and production of chemical plant,
such as filter-presses, autoclaves, fractionating columns, vacuum
pumps and stills, suction filters, enamelled iron, aluminium, and
stoneware vessels, etc., for the supply of which extensive works
have become necessary.

It is a frequently quoted remark of the late Lord Beacons-
field that the chemical trade of a country is a barometer of its
prosperity, and the chemical trade of this country has always
been regarded as a most important branch of our manufactures.

PROGRESS DURING FIFTEEN YEARS 1886-1900 191

Even those who might be inclined to regard our declining
position in the colour industry with more or less indifference
would consider the loss of a material portion of our general
chemical trade as nothing less than a national calamity. As
already pointed out, however, the two are indissolubly con-
nected, the coal-tar industry being an essential and inseparable
part of the chemical industry as a whole. It is with the object
of ascertaining our present and future prospects in the chemical
trade of the world that 1 propose to compare the relative develop-
ment of the colour industry in England and Germany during the
past fifteen years. It was at the commencement of this period,
that is to say in the year 1886, that Professor Meldola, in a paper
read before the Society of Arts, gave such a masterly account of
the position of the industry of this country at that date, and
sounded a warning note to our manufacturers and business men
regarding its future progress.

If an excuse is required for my venturing to refer again to a
subject upon which so much has been said and written already,
it is supplied by the fact that the warnings repeatedly given by
those who saw the future clearly (notably by Professors Meldola
and Armstrong) have remained largely unheeded by our business
men. The conclusions which are forced upon us are unfortun-
ately not of a reassuring nature for our national trade, but it is
well to remember that nothing is gained by burying our heads
in the sand, and that the cure of a disease can only be effected
after an accurate diagnosis of its cause.

The period which we have to consider has been one of
extraordinary activity and remarkable development in the coal-tar
industry, and before I pass to the economic aspect of the question
I shall ask you to consider very superficially some of the main
points in this advance. In no other industry than this have such
extraordinarily rapid changes and gigantic developments taken
place in so short a period, developments in which the scientific
elucidation of abstract problems has gone hand in hand with
inventive capacity, manufacturing skill, and commercial enterprise.
In no other industry has the close and intimate interrelation of
science and practice been more clearly demonstrated.

Born in 1856, the colour industry had already attained to a
considerable state of development by the year 1886. The period
prior to this might well be called the " rosaniline period," since
it is chiefly marked by the discovery and development of colour-

192 THE BRITISH COAL-TAR INDUSTRY

ing matters of the rosaniline or triphenylmethane group, such
as magenta, aniline blue, Hofmann violet, methyl violet, acid
magenta, acid violets, phosphine, Victoria blues, auramine,
malachite green, and acid greens. Individual members of other
groups had already been discovered, but the latter had not
yet attained to the importance which they were destined later
to occupy. This is especially the case with the class of colouring
matters containing the double nitrogen radical known as " azo "
colours. This group of compounds has, during the fifteen years
which we have to consider, attained to such enormous dimensions
and importance that this interval may fairly be termed the
" azo period." The number of individual compounds belonging
to this class, which have either been prepared or are at present
preparable, runs into many millions and far exceeds the members
of all other groups of colouring matters put together. In
commercial importance also they occupy a position at present far
in advance of any other group, the employment of some of them
(e.g. the " azo " blacks) amounting to many thousands of tons
annually. A great stimulus to the investigation of the azo
compounds was given by the discovery by Bottiger in 1884 of
the first colour possessing a direct affinity for cotton (Congo red),
which was followed within a few years by a rapidly increasing
series of colours of all shades having similar dyeing properties.
The azo colours known prior to this time were either basic
colours (aniline yellow, chrysoidine, Bismarck brown, etc.) or
acid wool colours (xylidine scarlet, croceine scarlet, etc.). The
great simplification of cotton dyeing brought about by the
introduction of the new group of azo colours " benzo " or
" diamine " colours as they were called led to a rapid increase
in their number, and compounds containing two, three, four, or
more double-nitrogen groups, linking together the residues of
various paradiamines (benzidine, tolidine, dianisidine, azoxy-
toluidine, paraphenylenediamine, naphthylenediamine, etc.) to
various naphthol-, amidonaphthol-, and naphthylamine sulphonic
acids made their appearance in quick succession. Simultaneously
therewith proceeded the discovery and investigation of the
various isomeric derivatives of naphthalene required as raw
products for the preparation of these colours, an investigation
which was largely aided by the classical research on the isomerism
of naphthalene compounds carried out in this country by Arm-
strong and Wynne.

PROGRESS DURING FIFTEEN YEARS 1886-1900 193

Another method of applying azo colours to cotton, by which
much faster shades are obtained, was introduced by Messrs
Read Holliday, of Huddersfield, in 1880, and consisted in
producing unsulphonated azo compounds on the fibre by direct
combination. Owing to the technical difficulties which were at
first encountered in applying this process it has only reached
its full development during the last few years and at other hands
than those of its discoverers. The most important colour
produced by this method is paranitraniline red, for which over
two hundred tons of chemically pure paranitraniline are manu-
factured annually.

The search for direct cotton colours led the author in 1887
to the discovery of primuline. This compound, having a direct
affinity for cotton and containing at the same time a diazotisable
amido group, could be used for the synthesis of various azo
colours on the fibre which were remarkable for great fastness to
washing. It has had a large employment for the production
of fast reds, and the new principle of dyeing which it introduced
has been considerably extended in other so-called " diazo " colours.
The closer investigation of the thiazol group, to which primuline
belongs, further led to the discovery of many other cotton
colours belonging to this family, amongst the most important
of which are the brilliant greenish-yellow called turmerine or
Clayton yellow, the light-fast chlorophenine or chloramine yellow,
the pure greenish basic yellow thioflavine, and the fast cotton
pink erica.

Passing over the stilbene azo colours and the basic azo
ammonium or Janus colours, there remains a class of azo com-
pounds to which 1 must shortly refer, namely, the mordant
azo colours, which with the growing demand for faster shades
have recently come into much prominence. In these compounds
the presence of an orthohydroxyl or carboxyl group gives to
the colour the property (following Liebermann and v. Kosta-
necki's rule) of combining with metallic mordants, especially
chromium oxide, and producing therewith insoluble and fast
lakes on the wool or cotton fibre.

We now come to the consideration of three analogously
constituted groups of colouring matters, namely, the azines,
oxazines, and thiazines. The laborious scientific investiga-
tions of Fischer and Hepp, Bernthsen, Kehrmann, and others
on the constitution of these groups of compounds, the first

194 THE BRITISH COAL-TAR INDUSTRY

members of which (methylene blue, safranine, and Meldola's
blue) were discovered in a very early stage of the industry
when little or nothing was known of their structure, combined
with the theoretical views on the quinonoid structure of such
colouring matters promulgated by Armstrong and adopted
by Nietzki, led to the discovery of many valuable new mem-
bers of these classes. Amongst the latter may be specially
mentioned the rosindulines, indoine blue, induline scarlet, rhodu-
lines, etc.

Passing to the pyrone and acridine groups in which much
investigation has also been conducted, the most notable advances
have been the discovery of the rhodamines, a class of pure
basic reds, and of the basic yellows and oranges allied tc
phosphine, namely, acridine yellow, benzoflavine, and acridine
orange.

It is in the alizarin group next to the azo group that the
greatest progress must be recorded. The demand for fasl
colours for calico printing and for dyeing chrome-mordantec
wool to withstand severe " milling " operations has led to c
long series of investigations and patents for producing nev^
derivatives of anthraquinone. These new products, known ir
commerce as alizarin Bordeaux, alizarin cyanines, anthracene
blues, alizarin viridine, alizarin saphirol, etc., are polyoxy- 01
amido-oxyanthraquinones, for the preparation of which eithei
alizarin or nitroanthraquinones are the usual starting-points.

Passing over some smaller groups, we now come to a ver)
peculiar class of dyestuffs containing sulphur, which although
discovered by Croissant and Brettoniere in 1873, remainec
confined to a single representative Cachou de Laval, unti
Raymond Vidal in 1893 obtained a very fast black colouring
matter, which dyed unmordanted cotton, by heating para-amido
phenol with sulphur and sodium sulphide. The possibility o
replacing aniline black in cotton dyeing by a direct colouring
matter, and possibly also of obtaining other shades which, thougl
dyed in a single bath, would resist subsequent " cross dyeing '
of the wool in mixed fabrics, lent an immense impulse to th<
study of this class of colouring matters ; and although thei
molecular structure still remains wrapped in obscurity, man]
new representatives have followed each other in rapid succession
ranging in shade from blacks of various hues to browns, olives
greens, and blues. As the most important of these I

PROGRESS DURING FIFTEEN YEARS 1886-1900 195

mention Vidal black, immedial black, katigene black, immedial
blues, pyrogene blues, katigene brown, katigene green, etc.

It may fairly be claimed, however, that the greatest triumph
of the coal-tar industry for the past fifteen years has been the
successful production of artificial indigo on a large manufacturing
scale.

Returning from the scientific to the economic aspect of the
subject, I shall ask you now to consider what share we have
obtained in the great expansion of trade resulting from all these
new discoveries, many of which have originated in this country.
The development of the industry in Germany is well illustrated
by the following figures :

EXPORTS FROM GERMANY TO THE WORLD

1885.

1895.

1899.

Tons.

Aniline oil and salt ....
Coal-tar colours (excl. alizarin) .
Alizarin colours ....

1713
4646
4284

7,135
15^89
8,927

!7> 6 39

Again, if we take values, we find that total exports of coal-
tar colours from Germany amounted in 1894 to 2,600,000,
and in 1898 to 3,500,000, an increase of nearly a million in
four years. The latter figure is practically the same as that
given by Per kin as an estimate of the world's total production in
1885, showing how great the increase has been since this date.

The value of Germany's entire production is somewhat
difficult to arrive at. Witt, in his report on the German chemical
exhibit at the Paris Exhibition, gives as the value of the total
chemical industry of Germany for the year 1897 the enormous
sum of 46^- million pounds sterling. Of this sum Lef&vre
estimates that at least one-tenth may be put down to colouring
matters, and another tenth to raw, intermediate, and synthetic
products from coal tar other than colours, and he thus assigns
for the total annual value of the coal-tar industry of Germany
the sum of nine to ten million pounds sterling. With the
increase in the production of synthetic indigo, it may be taken
to-day to considerably exceed this figure.

196 THE BRITISH COAL-TAR INDUSTRY

One may well wonder what becomes of this enormou:
quantity of coal-tar products. According to the United State;
consular reports the 3^ million pounds' worth of coal-tar colour;
exported by Germany in 1898 were consumed as follows :

The United States took .... .750,000 worth
The United Kingdom took . . . 730,000
Austria and Hungary ... 350,000
Italy . . 225,000

China ,, ... 270,000

whilst the rest of the world took the remainder.

The great increase in production in Germany is furthe
shown by the growth in the capital and number of workpeopL
employed. Thus according to a report of the Badische Works
recently issued, the capital of this company, which was increasec
in 1889 from 900,000 to 1,050,000, will be further augmente(
this year by the issue of 750,000 of debentures. The numbe
of workpeople employed by this company in 1900 was 6485, a
against 4800 in 1896, an increase of over 33 per cent, in fou
years. The firm of Leopold Cassella & Co., of Mainkur, nea
Frankfurt, have increased the number of their workpeople fron
545 in 1890 to 1800 in 1900.

Passing now to England, we find that the imports of coal-ta
colours into the country are steadily rising, as is shown by th
following figures taken from the Board of Trade returns :

IMPORTS OF COAL-TAR DYESTUFFS INTO ENGLAND DURING THE LAST
FIFTEEN YEARS (EXCLUDING INDIGO)

1886
1887
1888
1889
1890

542,000
569,000
609,200
594,400

1891 .

1892 . . 542,200

1893 . . 504,000

1894 . . 599,000

. 710,000

1896 .

1897 . . 695,40

1898 . . 739,00

1899 . . 708,80

1900 . . 720,00

Contrasted with this, the exports of coal-tar colours manu
factured in 'England have fallen from 530,000 in 1890 t<
366,500 in 1899. Comparing these figures with the rapidl;
increasing export trade of Germany, it is seen that wherea
formerly the English export trade in artificial colours was abou
one-quarter that of Germany, it does not now amount to a tenti
part. It is therefore only too apparent that we have had bu
little share in the great increase which this industry has experi

PROGRESS DURING FIFTEEN YEARS 1886-1900 197

enced during the past fifteen years, and that we have not even
been able to supply the expansion in our own requirements. In
order to ascertain what proportion of our own needs we at present
furnish, I am able to lay before you the following interesting
figures, which have been kindly supplied to me by the Bradford
Dyers 1 Association and the British Cotton and Wool Dyers'
Association, who together form a large proportion of the entire
dyeing trade :

COLOURING MATTERS USED BY BRADFORD DYERS'
ASSOCIATION

English, 10 per cent. ; German, 80 per cent. ; Swiss, 6 per
cent. ; French, 4 per cent.

COLOURING MATTERS USED BY BRITISH COTTON AND WOOL
DYERS' ASSOCIATION

Aniline Colours. English, 22 per cent. ; foreign, 78 per
cent.

Alizarin Colours. English, 1-65 per cent. ; foreign, 98*35
per cent.

The English Sewing Cotton Company have also very kindly
supplied me with a detailed analysis of their consumption, from
which it appears that out of a total of sixty tons of colouring
matters and other dyeing materials derived from coal tar only
9 per cent, were of English manufacture.

The following table of statistics of the six largest German
firms gives a fair picture of the present dimensions of the
industry in that country.

The joint capital of these six firms amounts to at least
i\ millions. They employ together about 500 chemists, 350
engineers and other technologists, 1360 business managers,
clerks, travellers, etc., and over 18,000 workpeople. Compared
with such figures as these the English colour manufacture
assumes insignificant proportions. The total capital invested
in the coal-tar colour trade in England probably does not exceed
500,000, the total number of chemists employed cannot be
more than thirty or forty, and the number of workmen engaged
in the manufacture does not amount to over a thousand.

198 THE BRITISH COAL-TAR INDUSTRY

POSITION OF THE Six LARGEST COLOUR WORKS IN GERMANY IN YEAR 1900

Badische
Aniline
Works.

Meister,
Lucius &
Bruning.

Farben-
fabriken
Bayer
&Co.

Berlin
Aniline
Co.

Cassella
&Co.

Farbwerk
Mlihlheim,
Leonhardt
&Co.

Total of
six largest
firms.

Capital

.1,050,000

833,000

882,000

441,000

Private

157,000

About

concern

^2,500,001

Number of

148

120

145

About 5oc

chemists

Number of

175

About 35C

engineers,

dyers, and

other tech-

nologists

Commercial

305

211

5oo

150

170

About 136

staff

Workpeople

6485

3555

4200

1800

About 1 8, 2

Per cent.

Dividends in

I2J

Not

1897

known

Dividends in

5 }

> j

1898

Dividends in

1899

Dividends in

> >

Nil

1900

A similar relative proportion is maintained in the number o
patents for new colouring matters and other coal-tar product
taken by the English and German firms, as is shown by th
following table :

COMPARISON OF NUMBER OF COMPLETED ENGLISH PATENTS FOR COAI
TAR PRODUCTS TAKEN DURING 1886-1900 BY Six LARGEST ENGLIS:
AND Six LARGEST GERMAN FIRMS

German Firms

Badische Aniline Works . . 179
Meister, Lucius & Briining . 231
Farbfabriken Bayer & Co. . 306
Berlin Aniline Co. . . .119
L. Cassella & Co. . . -75
Farbwerk Miihlheim, Leonhardt
& Co 38

English Firms

Brooke, Simpson & Spiller

Clayton Aniline Co. .

Levinstein .

Read Holliday & Co.

Claus & Ree .

W. G. Thompson .

To tal of six German firms . 948 Total of six English firms . 8

Nor does the potential loss which we have sustained by ou
inability to take advantage of a growing industry represent th

PROGRESS DURING FIFTEEN YEARS 1886-1900 199

sum total of our losses. The new colouring matters, made
almost exclusively in Germany, have in many cases been intro-
duced as substitutes for natural products, which were staple
articles of English commerce. Madder and cochineal have been
replaced by alizarin and azo scarlets, the employment of many
dyewoods has greatly decreased, whilst at the present moment
logwood and indigo are seriously threatened. Regarding the
indigo question, so much has been written that I do not propose
to occupy space in its further discussion, but will only point out
that the complete capture of the indigo market by the synthetic
product, which would mean a loss to our Indian dependencies of
3,000,000 a year, is regarded by the Badische Company as so
absolutely certain that, having already invested nearly a million
pounds in the enterprise, they are at present issuing 750,000 of
new debenture capital to provide funds to extend their plant for
this purpose. In the last annual report of the company they
say : " As regards plant indigo, the directors are prepared and
determined to meet this competition in all its possible variations
in value. Much strange matter has been published in India as
to improvements in the cultivation and preparation of natural
indigo, but the illusions of the planters and indigo dealers are
destined to be dispelled before facts, which, although they are
not known to them, will make themselves more felt the larger
the production of artificial indigo becomes."

Besides the loss of material wealth which the neglect of the
coal-tar trade has involved to the country, there is yet another
aspect of the question which is even of more importance than
the commercial one. There can be no question that the growth
in Germany of a highly scientific industry of large and far-
reaching proportions has had an enormous effect in encouraging
and stimulating scientific culture and scientific research in all
branches of knowledge. It has reacted with beneficial effect
upon the universities, and has tended to promote scientific
thought throughout the land. By its demonstration of the
practical importance of purely theoretical conceptions it has had
a far-reaching effect on the intellectual life of the nation. -How
much such a scientific revival is wanted in our country the social
and economic history of the past ten years abundantly testifies.

The position with which we are confronted is in truth a
lamentable one, and the way out is not so easy to find. In 1886
it could perhaps still be maintained that we held the key to the

200 THE BRITISH COAL-TAR INDUSTRY

situation if we chose to make use of it, inasmuch as the principal
raw products of the colour manufacture (tar oils, naphthalene,
anthracene, soda, ammonia, iron, etc.) were in great measure
imported from England. In a speech to the Academy of Sciences
of Munich in 1878 Professor von Baeyer had said : "Germany,
which in comparison with England and France possesses such
great disadvantages in reference to natural resources, has suc-
ceeded by means of her intellectual activity in wresting from
both countries a source of national wealth. Germany has no
longer to pay any tribute to foreign nations, but is now receiving
such tribute from them, and the primary source from which this
wealth originates has its home, not in Germany, but in England.
It is one of the most singular phenomena in the domain of
industrial chemistry that the chief industrial nation and the most
practical people in the world has been beaten in the endeavour
to turn to profitable account the coal tar which it possesses. We
must not, however, rest upon our oars, for we may be sure that
England, which at present looks on quietly while we purchase
her tar and convert it into colours, selling them to foreign nations
at high prices, will unhesitatingly cut off the source of supply as
soon as all technical difficulties have been surmounted by the
exertions of German manufacturers." 1 Professor von Baeyer
could not believe that the English manufacturer and capitalist
would stand calmly by and see an important industry which had
had its origin and early development in his own country taken
from beneath his nose without an effort to retain it. Yet the
initial advantages which our natural resources afforded us have
been neglected, and now in 1901 the conditions are completely
changed. The adaptation of condensing plant to the Westphalian
coke ovens has rendered Germany, though still a large buyer
from England, no longer dependent on English tar and ammonia ;
by the development of the ammonia-soda process she no longer
requires English alkali ; whilst all other raw products of the
colour industry can now be purchased in the commercial centres
of Germany at least as cheaply as in England, and some even at
lower prices. Through the shortsightedness, ignorance, and
want of enterprise of those with whom the care of the colour
industry in this country has rested, the opportunity has been
allowed to pass for ever. The English capitalist has passed over
as not sufficiently profitable for his consideration an industry
1 Quoted by Mr Levinstein, Jour. Soc. Chcm. Ind., 1886, p. 350.

PROGRESS DURING FIFTEEN YEARS 1886-1900 201

which at present amounts to nine or ten million sterling annually,
and from which his German confrere reaps a dividend of nearly
20 per cent. The English manufacturer has considered that a
knowledge of the benzol market was of greater importance than
a knowledge of the benzol theory, and after the early but brilliant
days in the infancy of the industry, when guided by such eminent
workers as Hofmann, Perkin, and Nicholson, commercial progress
and scientific investigation went hand in hand, but little encourage-
ment has been given here to chemical investigators and discoverers.
The control of the industry unfortunately soon passed into the
hands of men who had no knowledge and absolutely no apprecia-
tion of the science upon which their business rested, and, con-
cerned only with getting the ultimate amount of present profit,
discouraged all scientific investigations as waste of time and
money. The chemist who devoted himself to the elucidation of
the chemical constitution of a colouring matter was regarded by
them as an unpractical theorist of no value to a manufacturing
business. Even when he discovered new colouring matters of
commercial value they were so blind to their own interests, and
so incapable of believing that any practical good could come out
of such theoretical work, that in many cases they refused to
patent or in any way take advantage of the discoveries made by
him. During recent years this attitude has certainly undergone
considerable modification, and some attempt has been made to
call in the aid of the science so long neglected. Certain firms,
indeed, must be given the credit of endeavouring to pursue a
more enlightened policy, but these attempts have been of a more
or less sporadic nature and always directed too much in the
expectation of realising immediate financial results. The
difficulties which must be encountered in the attempt to regain
the lost ground are of necessity very great, and are quite un-
appreciated by our business men. It seems, in fact, to have been
the opinion of the public and the average financial man that this
industry ought to be easily won back by us by the establishment
of a few technical schools, the engagement of a dozen chemists,
and the investment of a few thousand pounds in new plant,
forgetting that the supremacy of our German competitors has
been gained by years of patient toil, by the work of hundreds
of trained chemists, and by the outlay of millions of capital.
Who can be surprised therefore if such expectations have not
been realised, and if in spite of some notable successes the general

202 THE BRITISH COAL-TAR INDUSTRY

position of the colour trade in England at the present day, at a
time when even the German trade is suffering from the general
depression, looks worse than at any previous period ? During
years of stagnation in this country the German manufacturers
have been realising large profits, which they have employed in
consolidating their businesses, writing off the value of their
buildings and plant, and accumulating enormous reserves (the
reserve of the Badische Company is over a million pounds) :
they have gathered round them perfectly working organisations,
comprising enormous staffs of scientifically and practically trained
research chemists, factory chemists with highly specialised know-
ledge, chemical engineers, dyers, and others ; their travellers
and agents are in every part of the globe ; by long manufacturing
experience and unremitting endeavour to improve their processes
and plant they have brought the yields and quality of their
products to such a state of perfection that even when the manu-
facture of these products is no longer covered by patents they
are able to produce them at a cost price which is impossible to
anyone commencing their manufacture ; they have hedged them-
selves about with a perfect stockade of many hundreds of patents,
have accumulated in their laboratories thousands of intermediate
products ready at any time to be subjected to any new treatment
or combination which research or theory may suggest as likely
to yield new results. By the complete range of colours which
they are able to offer in each group of dyestuffs, whether basic
colours, acid colours for wool, fast colours dyeing on metallic
mordants, diazotisable colours, or direct colours for cotton, and
by the invaluable aid and assistance which they can give the
dyer in his daily work they are enabled to retain his custom
even if it sometimes happens that a better and a cheaper article
is offered him by the home producer.

Where, then, are we to look for an improvement ? Some
would find a remedy in the imposition of heavy protective tariffs ;
but such tariffs in France have not availed to prevent a similar
state of things there, and protection in colouring matters might
have a very detrimental effect upon the textile industries of the
country. Others expect salvation from the extension of technical
schools ; but, laudable as is the aim of these institutions, I cannot
see how they can effect much until their raw material is of a very
different character from what it is at present, and until the public
can be completely disabused of the fallacy that a year or two of

PROGRESS DURING FIFTEEN YEARS 1886-1900 203

technical training pumped into an ignorant schoolboy will pro-
duce a better works chemist than a university course of scientific
study laid upon the foundation of a good general education.
Mr Levinstein again bases his hopes for the future upon a
reform of the patent laws, and seeks to compel all patented
processes to be worked in this country. Although I am inclined
to believe that a portion of our present troubles has been
brought about by bad patent law, framed mainly from an
engineering and not from a chemical point of view, which seems
specially designed to foster foreign trade at our own expense,
yet 1 cannot attribute to this cause a too preponderating influence,
and am doubtful whether its removal now would materially
improve the position. The remedy for the present state of
affairs must of necessity be a slow one, and in my opinion can
only be found in a better appreciation of the value of science
throughout the length and breadth of the land. Until our
Government and public men can be brought to realise the
importance of fostering the study of science and of encouraging
all scientific industries, until our schools and universities ap-
preciate the importance of a scientific education, until the rewards
for public services in science are made equal to those in other
branches of the public service, so long will science continue to
be held in insufficient esteem in our country, and the best and
most promising of our rising young men will be deterred from
adopting chemistry as a profession. It is not so much the
education of our chemists which is at fault as the scientific
education of the public as a whole.

XII. : 1901
THE INDIGO CRISIS

(Journal of the Society of Dyers and Colour ists y 1901, p. 157)

IT is now generally recognised that the threatened replace-
ment of natural indigo by the synthetic product is a matter not
only of scientific interest, but one which may have far-reaching
economic and political consequences ; and mainly on this account
the public interest has been aroused to an extent which is very
unusual in matters of this character. This has been reflected
by questions in Parliament and correspondence in the Times,
Nature, and other papers, as well as in the more directly
concerned trade journals.

Another reason for the widespread interest evinced is
the very impressive manner in which the problem of the
artificial production of indigotin has been attacked. The fact
that about ; 1,000,000 has been spent by a single German firm
in working out the process and in preparing for the commercial
introduction of the product has appealed to the public
imagination as a concrete example of German enterprise, and
has also led many to realise the magnitude of the interests
involved.

Within the last few years many papers and notes on natural
and artificial indigo have appeared in this Journal, and the
various aspects of the subject will be more or less familiar to
members, but the general interest was greatly intensified by the
publication of the lectures delivered by Professor von Baeyer and
Dr Brunck at the opening of the Hofmann House in Berlin in
October 1900. Von Baeyer's lecture dealt chiefly with the
theoretical aspect of the question, while Dr Brunck dealt mainly
with the manufacturing and commercial side.

Dr Brunck's lecture will undoubtedly become historical, and
a translation is given almost in extenso :

204

THE INDIGO CRISIS 205

THE HISTORY OF THE DEVELOPMENT OF THE
MANUFACTURE OF INDIGO

In 1868 the first complete synthesis of a vegetable colouring
matter was accomplished. Graebe and Liebermann had pointed
out the path from anthracene to alizarin, and chemical industry
hastened to follow that path. Magnificent was the result of
this undertaking, and the industry of coal-tar colours gained a
victory which justified its further hopes and gave it the courage
to direct its efforts toward a still higher goal, namely, the
conquest of the oldest and most important of all colouring
matters, indigo.

The observation by Emmerling and Engler, that indigo
could be made from orthonitroacetophenone, did not supply
chemical industry with an effective base. However, after Ad.
Baeyer had added the synthesis of isatin to his previous
synthesis of indigo from the former, he discovered, in 1880,
his beautiful synthesis of indigo from orthonitrophenylpropiolic
acid, and thus, from an industrial point of view, the question
of manufacturing indigo synthetically assumed concrete and
definite form.

Orthonitrophenylpropiolic acid is a derivative of cinnamic
acid ; the latter could, at that time, be made by means of
" Perkin's reaction " from benzaldehyde, and this, since the
introduction of malachite green into the arts, had become a
product much employed in the coal-tar colour industry, and was
easily made from toluene.

The Badische Anilin- und Soda-Fabrik and the Farbwerke
vorm. Meister, Lucius & Brilning, at Hoechst-on-the-Main,
acquired Baeyer 's patents, and now, in conjunction with the
inventor, they began the technical investigation of the problem,
which was destined to occupy a period of more than twenty
years.

The task was begun with enthusiasm, and the phases of
the individual syntheses were systematically investigated and
studied. Of the circumspection and thoroughness with which
the subject was studied in all its aspects, but slight conception
is given by the patents subsequently taken out.

I have before me a tabulation of all the patents bearing on
this subject, and it shows that in Germany alone there are
152 patented inventions.

206 THE BRITISH COAL-TAR INDUSTRY

It soon became possible to replace " Perkin's process " of
making cinnamic acid by the benzal chloride and sodium acetate
process. Through this process, cinnamic acid became a cheap
article of manufacture, instead of being an expensive laboratory
preparation. But, on the other hand, orthonitrocinnamic acid
was at first, comparatively, very expensive.

On nitrating cinnamic acid according to the methods then
in use, only a small portion of the cinnamic acid was converted
into the orthonitro compound, while the greater part was
converted into the paranitro derivative, which is not available
for the production of indigo.

It was, therefore, necessary to alter this unfavourable result,
and by employing cinnamic acid ester in place of the free acid,
it was possible to so conduct the operation that 70 per cent, of
the acid could be converted into the orthonitro compound.

The subsequent bromination of the orthonitrocinnamic acid,
as well as the conversion of the resulting dibromide of this
acid into orthonitrophenylpropiolic acid, still offered many
difficulties. But the investigations were carried on with
enthusiasm and with energy, and, as early as the spring of 1881,
they had so far progressed that it was possible to continously
manufacture the " propiolic acid."

This process, however, was not available for the direct
manufacture of indigo, because of the high cost of production,
which, in spite of ease of execution and of good yields, exceeded
that of the vegetable product.

However, attempts were made in other directions to render
" propiolic acid " of use in the arts.

At that time indigo printing was a secret of but few firms,
and was an operation requiring much experience. This
circumstance suggested the conversion of "propiolic acid"
into indigo upon the fibre, and this conversion was possible after
Caro had discovered in sodium xanthate a reducing agent
suitable for this purpose.

" Propiolic acid " was introduced into cotton printing, and
was employed especially for the production of those delicate
patterns which had hitherto been produced by means of indigo,
according to the then prevailing methods, but only with difficulty.
Unfortunately, however, this success was more of a theoretical
than of a practical nature, for " propiolic acid " was never used
generally.

THE INDIGO CRISIS 207

Although the results of this painstaking labour did not fulfil
the expectations of the workers, this fact did not shake their
confidence nor diminish their activity. They recognised in the
results and the experience so far collected, a foundation upon
which it was possible to base further work.

The year 1882 brought with it Baeyer and Drewsen's
synthesis of indigo from orthonitrobenzaldehyde and acetone.
This process, which likewise passed into the possession of the
Farbwerke, at Hoechst, and of the Badische, was, in turn,
subjected to technical investigation. The formation of indigo
was, indeed, more smooth than by means of the cinnamic acid
process, but the development of a rational method of manufacture
of orthonitrobenzaldehyde was beset with difficulties which at
first appeared insurmountable.

After it had been determined that, in spite of the greatest
possible variations of the conditions observed, the direct nitra-
tion of benzaldehyde yielded only insufficient amounts of the
orthonitro derivative, which was accompanied by metanitro-
benzaldehyde, which is useless for indigo manufacture, ortho-
nitrobenzyl chloride was employed as the initial material for the
production of orthonitrobenzaldehyde ; this orthonitrobenzyl
chloride is formed along with the paranitro body by the nitra-
tion of benzyl chloride, but again, only in subordinate quantities.
All attempts to arrive at a better result failed.

There now remained the possibility of converting ortho-
nitrotoluene into orthonitrobenzaldehyde, either by chlorination
and subsequent oxidation, or by direct oxidation. These experi-
ments were carried on for years, but the difficulties in the way
of completely chlorinating orthonitrotoluene, and satisfactorily
working up the chlorination product could not, for the time being,
be overcome.

When, in 1886, the Badische Anilin- und Soda-Fabrik had
found the method, which has recently also been patented by the
Societe des Usines du Rh6ne ancien. Gilliard, Monnet and
Cartier, of directly oxidising methyl derivatives of benzene to the
corresponding aldehydes, without intermediate conversion into
chlorination products, hope was again entertained of arriving at
orthonitrobenzaldehyde by oxidising orthonitrotoluene. How-
ever, these experiments were unsatisfactory and appeared to be
without a practical future. The probability that orthonitro-
benzaldehyde would serve as a starting-point for the synthetic

2o8 THE BRITISH COAL-TAR INDUSTRY

production of indigo became more and more remote. The cost
of production of synthetic indigo was not only dependent upon
the price of toluene, which was available in but limited quantity,
but also upon the utilisation of the paranitro by-product.

In 1893 the synthesis of indigo from orthonitrobenzaldehyde
was made technically available by Kalle & Co., in a manner
similar to the way in which the " propiolic acid " process had
already been applied. This firm succeeded in converting the
intermediate product arising during the formation of indigo
from the aldehyde and acetone, namely, orthonitrophenyllacto
ketone, into a soluble bisulphite compound, and this found
application in printing. This product, which Kalle & Co. have
placed upon the market as " indigo salt," is employed for the
purposes of printing indigo upon cotton, and is superior to
" propiolic acid," on account of the ease of its application.

It almost seemed as though the investigation of this branch
of the subject had ceased. Several years passed by, during which
not a single new observation or fact connected therewith was
published. It was not until 1896, and when, indeed, it seemed
extremely likely that we should solve the problem of a technical
indigo synthesis along lines which we had followed in the mean-
time, that it appeared from published patents that this apparently
abandoned field had, nevertheless, been assiduously cultivated.
The Farbwerke, at Hoechst, had arrived at a technically useful
process of converting orthonitrotoluene into orthonitrobenzal-
dehyde by treating the mixture of products obtained on
chlorinating orthonitrotoluene with aniline or aniline sulphonic
acid, and which can then be readily isolated. The product so
obtained is converted into the corresponding benzylidene com-
pound, which latter, on treatment with acids, is converted into
orthonitrobenzaldehyde, and aniline or aniline sulphonic acid.

The method of producing orthonitrobenzaldehyde by direct
oxidation of orthonitrotoluene to its aldehyde has since been
further developed by the Socit des Usines du Rh6ne, as well as
by us, the Badische Anilin- und Soda-Fabrik, and now yields
better results.

While it is thus possible to produce orthonitrobenzaldehyde,
the conditions for the manufacture of indigo from this substance
are, at present, so far favourable, that, on account of the increased
consumption of paranitrotoluene during the last few years, there
has arisen a corresponding surplus of orthonitrotoluene as a by-

THE INDIGO CRISIS 209

product. But the amount of indigo which could be manufactured
therefrom would necessarily be confined to narrow limits, and
could constitute but a small part of the consumption.

If, however, this branch of chemical industry were so situated
as to be able to entirely disregard the utilisation of the paranitro
by-product, yet its ability to expand and to increase would
always be circumscribed, and its foundation would be uncertain,
so long as its initial material, toluene, is available in but limited
quantity.

Permit me, in explanation of the foregoing, to call your
attention to some statistical figures. Benzene and toluene are
principally used in the manufacture of coal-tar colours, and their
intermediate products, and their annual production is at present
about 25,000 to 30,000 tons. On an average, there will be pro-
duced about four parts of benzene for every one part of toluene.
Consequently, there are annually available about 5000 or 6000
tons of toluene, which are just about sufficient to satisfy the
present needs. The market value of toluene is, as against
previous years, considerably higher than that of benzene, and
with increasing demand for toluene, its market value must rise,
so long as the amount of available toluene, which is regulated by
the demand for benzene, does not increase.

The toluene now on the market not being available for the
manufacture of indigo, it would be necessary to obtain a new
supply of toluene.

This would mean that for every ton of toluene thus obtained,
four tons of benzene would have to be made ; some use would,
therefore, have to be found for this benzene.

According to a recent published statement concerning the
yield of indigo from toluene, by the newest and best technical
methods, one pound of indigo requires about four pounds of
toluene. Therefore, the total amount of toluene now produced
would suffice, at most, for the production of one-quarter of the
world's consumption of indigo, which may be estimated at about
1 1,000,000 pounds of 100 per cent, strength ; that is, it would be
necessary to add to the present production of coal-tar hydro-
carbons four times the amount which is made at present, in order
to completely replace vegetable indigo.

On account of this state of affairs, we have for a long time
had but little hope that the indigo syntheses which I have so far
discussed could ever be capable of producing indigo in large

210 THE BRITISH COAL-TAR INDUSTRY

quantity, i.e. completely replacing vegetable indigo. It was,
therefore, necessary for us to direct our efforts towards obtaining
an indigo synthesis which was based upon an easily accessible
initial material, and, above all, an initial material whose supply
was sufficient and adequate.

It was then that is, in 1890 that the chemical world was
astounded by the discovery of Heumann, namely, that indigo
could be obtained by melting phenylglycocoll with caustic potash.

Through this discovery, the question of the technical produc-
tion of indigo was placed upon a new basis ; the efforts of the
industry in this direction were, by this means, led into new
and promising paths. Promising, because this new synthesis
fulfilled the first requirement of manufacture on a large scale,
namely, the cheap and easy production of the required initial
materials which, in this case, were solely aniline, acetic acid,
chlorine, and alkali.

This invention was likewise acquired by the Badische Anilin-
und Soda-Fabrik, and the Farbwerke at Hoechst, who at once
took up the technical investigation of this subject, at first with
the assistance of the inventor, but he, unfortunately, died in
1894, and so did not see the completion of the structure founded
upon his last researches.

Although the Heumann synthesis fulfilled the first require-
ment for technical availability, namely, the easy supply of the
initial materials, nevertheless it did not satisfy the requirements
with respect to the yield of dyestuff. Although, after numberless
experiments, it was possible to improve this yield, yet the im-
provement was not such as to make manufacture profitable.

Experiments to obtain a more satisfactory formation of indigo
by substituting for the alkali-melt another condensation agent,
led us, and later also the Farbenfabriken vorm. Friedr. Bayer
& Co., at Elberfeld, to the observation that an indigo-sulpho
acid could be obtained from phenylglycocoll by the action of
fuming sulphuric acid. However, this sulpho acid does not
possess the good dyeing properties which are possessed by the
sulpho acid obtained by the sulphonation of indigo, and this
process likewise remained without technical application.

The hopes which had been placed in phenylglycocoll as the
basis for an indigo synthesis proved vain.

Other glycocolls behaved similarly to phenylglycocoll. Tolyl-,
xylylglycoll, and the glycocolls of the naphthylamines yielded

THE INDIGO CRISIS 211

scarcely any colouring matter, or such small amounts that it was
impossible for them to come into consideration at all. Further,
it had been ascertained that the derivatives of indigo were inferior
to indigo itself, so far as beauty of shade is concerned, and did
not meet the demands of the dyer.

But Heumann had also found that the glycocoll of anthranilic
acid, that is, phenylglycocoll-orthocarboxylic acid, likewise yields
indigo when treated in a similar manner. In this case the forma-
tion of indigo takes place far more smoothly, and experiments
soon made it appear that this process was capable of development
and perfection. But the industrial realisation of this synthesis,
for which the production of anthranilic acid as initial material
was needed, involved conditions far less favourable than those
for the production of phenylglycocoll, and was beset by extra-
ordinary difficulties, which at times appeared insurmountable.
These could be cleared away only by men who, in addition to
possessing a thorough and a broad chemical knowledge, likewise
possessed great technical skill, and who were experienced in
solving difficult chemical problems, organic as well as inorganic,
attacking them with persistence and with ingenuity, and finally
bringing them to a successful issue. Fortunately, we had the
assistance of such men, and after almost seven years of labour
we succeeded in solving the problem.

This now brings me to a discussion of the development of
the process of manufacturing indigo as it is to-day carried on by
us. Phenylglycocoll- or thocarboxylic acid is produced from
anthranilic acid and monochloracetic acid. For the manufacture
of the former we were at first dependent upon orthonitrotoluene ;
orthonitrotoluene could be oxidised to nitrobenzoic acid, and
this could then be reduced, or the operations could be reversed,
and the reduction product of orthonitrotoluene, namely, ortho-
toluidine, could be oxidised in appropriate manner (e.g. by means
of its acetyl compound) to anthranilic acid. This process, however,
was beset by the same obstacles as was the manufacture of indigo
from orthonitrobenzaldehyde. But this was not to prove fatal,
for there was a process available, which had been discovered in
1890 by HoogewerfF and Van Dorp, and which, starting from
phthalic acid, produced anthranilic acid. It was A. W. von
Hofmann who, by his gifted investigation of the peculiar action
of alkaline solutions of bromine upon amines, furnished these
investigators with the basis for their researches. They succeeded

212 THE BRITISH COAL-TAR INDUSTRY

in converting phthalimide into anthranilic acid by means of an
alkaline solution of bromine.

With phthalic acid as initial material for anthranilic acid,
naphthalene became the initial material of the indigo synthesis,
and this fact created the first reliable basis for indigo manufacture
on a large scale.

From this time on I was firmly convinced that the path which
was now being followed must lead to the achievement of the
great object : The replacement of vegetable indigo by synthetic
indigo.

In fact, naphthalene is an initial material which, for the pur-
pose of indigo manufacture, is available in unlimited quantities.
Based upon reliable information, I estimate that the amount of
coal tar which is annually treated for its contained hydrocarbons,
and which I assume to be two-thirds of the total world's output,
contains from 40,000 to 50,000 tons of naphthalene, and of this
only about 15,000 tons, which correspond to the present-day
consumption, are isolated. For the purposes of indigo manu-
facture, therefore, there remain at least 25,000 tons of naphthalene
which hitherto, on account of lack of market, were burned to
lamp-black or remained dissolved in the heavy oils, but which
can also be isolated by the same means and at the same cost as
the aforementioned 15,000 tons.

The naphthalene in this way available is, however, more than
sufficient to cover the amount required for the manufacture of
the world's consumption of indigo.

The auspices for the solution of this great problem were
therefore favourable, and it became necessary to bring to bear
upon its accomplishment all the ability and energy and all the
expedients and means known to the present-day industry, and to
make use of all the experience which had been acquired in manu-
facturing operations in the course of a great number of years,
and to spare no labour and no expense in order to make every-
thing, which could possibly contribute to its success, serviceable
to this undertaking.

And, in fact, there was a great work still to be performed.
The systematic investigation of the individual phases of the
process occupied the attention and activity of our best men
through many years.

We did, indeed, at that time possess the best process then
known for the manufacture of phthalic acid. This consisted in

THE INDIGO CRISIS 213

the oxidation of naphthalene by means of chromic acid, and it had
been first developed and perfected by us, and had been in opera-
tion for twenty years. But, since phthalic acid so produced was
still too expensive, and it was not to be expected that this method
of manufacture which had been employed by us for so long a
time was still susceptible of an essential improvement, it was
necessary to bring about the oxidation of naphthalene by a
cheaper means.

Our chemist, E. Sapper, succeeded in finding an entirely new
method for the production of phthalic acid, which consisted in
heating naphthalene with highly concentrated sulphuric acid.

A most comprehensive series of experiments was carried out
to develop this process to practical utility. The effect of addi-
tions of the most various kinds to the reaction mass was tried,
and, in the end, mercury was found to be an agent which brought
the yields to a satisfactory point. Even though an accident,
namely, the destruction of a pocket containing mercury, was an
assistance, this accident merely hastened the solution of the
problem. But without it the object would certainly have been
achieved.

On a small scale, the results were perfect. But the manu-
facture on a large scale required enormous efforts, much time and
patience, and the question of apparatus especially required many
and very expensive experiments for its solution.

In the first place, the oxidation of the naphthalene required
large amounts of strong sulphuric acid, and the nearly complete
and most advantageous recovery of this was the prime condition
of success. Had we been compelled to accomplish this regenera-
tion of the sulphuric acid in lead chambers, then this new process
would hardly have offered any advantages over the chromic-acid
process.

It was at this stage that our new sulphuric-acid process, which
was developed by R. Knietsch, stood us in good stead. The
contact process, which had become available for the industrial
production of fuming sulphuric acid, through the suggestion of
C. Winkler, in 1875, has since been developed by us so that
the production of sulphuric anhydride, by the direct union of
pyrites burner gases that is, of sulphur dioxide and the oxygen
of the air, has now become more profitable for the manufacture
of sulphuric acid than is the lead-chamber process. This has
been published both in chemical literature and in our patents.

2i 4 THE BRITISH COAL-TAR INDUSTRY

Our new process of making phthalic acid was, therefore,
directly dependent upon this sulphuric acid manufacture, since
the latter made it possible to directly convert the sulphur dioxide
arising from the oxidation of the naphthalene into concentrated
sulphuric acid in the cheapest possible manner.

You may be able to form an idea as to the part which this
sulphuric-acid manufacture plays in our process from the fact
that, from our present production of phthalic acid, there result
annually 35,000 to 40,000 tons sulphur dioxide which we must
reconvert into sulphuric anhydride. For this purpose a plant of
about the same size is required as for an equal weight of iron
pyrites.

Now, and only now, was the cycle of the process completed.
The oxygen of the air now converts naphthalene into phthalic
acid in the cheapest manner possible, and our new sulphuric-acid
process thus becomes one of the foundations of indigo manu-
facture. This is a firm foundation !

While these labours, which extended from 1891 until 1897,
were in progress, the manufacture of the other initial materials
was investigated and worked out with the same energy.

Large amounts of chlorine are required in the manufacture
of the requisite amount of chloracetic acid, and also for the
oxidation of phthalimide to anthranilic acid, and it was therefore
necessary to create a cheap source of chlorine. Even now we
must chlorinate 4,400,000 Ib. of glacial acetic acid an amount
of acetic acid equivalent to 130,000 cubic yards of wood !
Neither Weldon's process nor Deacon's process would answer
our purpose ; the former, because the chlorine it yielded was too
expensive, and the latter, because its chlorine was too dilute.

In the meantime, however, the researches on the electrolytic
production of chlorine from alkali chlorides had made consider-
able strides. A number of electrolytic processes were, indeed,
known by name, but their real value was not known, and it was
therefore necessary to select from these that process which was
best adapted to the requirements of indigo manufacture ; and,
since great expenditure is involved in plant of this nature, it was
necessary to exercise the greatest caution in this selection.

We believe that we are justified in holding that, through
acquiring the process of the Chemische Fabrik Elektron in
Griesheim-on-the-Main, we possess the best process of the
present day.

THE INDIGO CRISIS 215

Only in point of purity the resulting chlorine did not satisfy
our high requirements, and here our process for the liquefaction
of chlorine enabled us to convert it into its purest form. The
development of the process for the production of chloracetic acid
was also a difficult task ; however, this branch of manufacture,
which, at first, was most disagreeable, has finally developed into
a comparatively simple manufacturing operation.

The manufacture of phthalimide, of anthranilic acid, and of
phenylglycocoll-orthocarboxylic acid itself, the real mother-sub-
stance of indigo, was more difficult than it at first appeared to be.
Whole series of systematic experiments had to be carried out, in
order to determine the conditions under which it was possible to
obtain a maximum yield of pure acid.

One of the most difficult problems was the proper carrying
out of the melting process on the large scale ; that is, the con-
version of phenylglycocoll-orthocarboxylic acid, by heating it
with alkali, into the leuco compound which, on oxidation with
air, yields indigo. These experiments, in the execution of which
R. Knietsch, the able and successful manager of our indigo de-
partment, and P. Seidel took most active part, were carried on
for years. New apparatus had to be invented and constructed
before the process was so far developed as to be adapted for
continuous manufacture.

It may be mentioned, in passing, that during the determina-
tion of those conditions which would bring about a satisfactory
course of the melting operation, free indoxylic acid was manu-
factured which, under the name " indophor," has found applica-
tion in cotton printing, namely, for the production of indigo
upon the fibre in a manner similar to that in which " propiolic
acid " and " indigo salt " are employed.

The indigo which is obtained from the water solution of this
melt, by means of air, is crystalline. In those cases where an
especially fine state of division is desired, such as in the fermenta-
tion vat, the so-obtained indigo is converted into a sulphate by
means of sulphuric acid, and this is decomposed with water, and
is thus reconverted into the original indigo in the form of a loose
powder, which is extremely easily soluble in the vat.

I have attempted to present to you, in a short sketch, the
history of the development of a new manufacture, and it now
devolves upon me to more clearly bring out a few considerations
which may be adapted to indicate, at least, the influence of this

216 THE BRITISH COAL-TAR INDUSTRY

manufacture upon the development of important industries, as
well as upon future economic changes.

The advantages which the synthetic product possesses over
the vegetable product have been presented so frequently on other
occasions, that in this direction I can be very brief.

The uniformity and the constant strength of synthetic indigo,
its absolute freedom from foreign admixture, its easy reducibility
when finely divided, and the ease of application which is thereby
secured for the dyer, are to be mentioned as its principal ad-
vantages, as against the constantly varying strength and the
difficult reducibility of the commercial brands of vegetable indigo.
These advantages free the dyer from oppressive dependence upon
the dealers, because, on account of lack of methods of accurate
determination, he has been obliged to purchase his stock, not
according to its actual value, but according to external and
easily misleading characteristics. These advantages of the
synthetic product now guarantee him absolute uniformity and
perfect quality.

In spite of these advantages, synthetic indigo had to over-
come many obstacles which were placed in the way of its intro-
duction. It was but natural that its quality was discredited by
those to whose interest it was to do so ; this was done, for
example, by stating that the impurities contained in vegetable
indigo, and which were absent from the synthetic product, were
essential to the dyeing process. Again, it was claimed that the
indigo which we brought into commerce was nothing more nor
less than refined vegetable indigo !

One of the greatest obstacles in the way of its introduction,
however, was the fact that the conception of a "chemical
individual " is for the most part unknown to those who are not
chemists. It was impossible for such to comprehend the fact
that two bodies of different origin, such as vegetable indigo and
synthetic indigo, could be identical ; synthetic indigo was
designated as a substitute and adulterant of vegetable indigo,
and it was attempted to place it on the same plane with those
aniline dyestuffs that dye a similar shade.

But such deceptions and carpings could not long prevail
against the facts.

Synthetic indigo, in accordance with its very great purity,
yields brighter shades. Curiously enough, this circumstance also
acted at first, though of course only in isolated instances, as an

THE INDIGO CRISIS 217

obstacle to its introduction ; thus, for example, one or two of the
German military authorities raised an objection because cloth
dyed with our pure indigo possessed a somewhat brighter shade
than did cloth which had been dyed according to the old method,
with impure indigo, and which served as the standard of
comparison.

On account of its easy reducibility and uniformity, dyeing
with pure indigo has become an operation equal in ease and
simplicity with the dyeing with any other ordinary dyestuff,
whilst, formerly, it was only possible after acquiring considerable
experience by prolonged practice to obtain a desired shade
with certainty, when using vegetable indigo, which, as is known,
is available only in brands of the most varying degrees of
purity. This latter art, which is often inherited from genera-
tion to generation, has lost much of its value through synthetic
indigo, and on this account the new product was accorded a
most unfriendly reception by many an indigo dyer who was
conscious of his own especial skill.

When, in July 1897, we had succeeded in so far reducing
the cost of manufacture of synthetic indigo that we could suc-
cessfully compete with the lowest price which vegetable indigo
had ever reached, we decided to first erect a plant which would
enable us to supply the consumption of this colouring matter
in Germany, and in so doing arrangements were made so that,
in case of success, our capacity could be increased at will.

As we were ignorant as to how cheaply the planters could
supply vegetable indigo in the course of the impending conflict,
and also because there is a possibility that a cheaper and simpler
process for the manufacture of indigo might be found, our
venture was subject to a very great risk ; because, for its suc-
cessful prosecution, extraordinary financial resources were
necessary, and, as a matter of fact, we have, to-day, invested
about 900,000 for this purpose.

Up to the present, the results which we have achieved
correspond to our expectations, and we hope to be victorious in
the long and arduous struggle that is before us.

Formerly, the value of the indigo annually produced was
estimated at 4,000,000 to 5,000,000 ; even at the present
prices, which are essentially lower, the value may still be
2,500,000 to 3,000,000.

Although, up to the present, we have succeeded in securing

218 THE BRITISH COAL-TAR INDUSTRY

to German industry but a part of this sum, and thereby making
the German consumer independent of foreign countries, and in
retaining for Germany those sums of money which have hitherto
been paid to foreigners for indigo, yet it is probably merely a
question of time when the entire consumption of indigo will
be provided for synthetically, and thus large sums will pass from
foreign countries to Germany.

The quantity of indigo which we produce annually, even at
this date, would require the cultivation of an area of more than
a quarter of a million acres of land (390 square miles) in the
home of the indigo plant. The first impression which this fact
may be likely to produce is that the manufacture of indigo
will cause a terrible calamity to arise in that country ; but
perhaps not. If one recalls to mind that India is periodically
afflicted with famine, one ought not, without further considera-
tion, to cast aside the hope that it might be good fortune for
that country if the immense areas, now devoted to a crop which
is subject to many vicissitudes and to violent market changes,
were at last to be given over to the raising of breadstuff's and
other food-products. For myself, I do not assume to be an
impartial adviser in this matter, but, nevertheless, I venture to
express my conviction that the Government of India will be
rendering a very great service if it should support and aid the
progress, which will in any case be irresistible, of this impending
change in the cultivation of that country, and would support
and direct its methodical and rational execution.

I have reached the end of my lecture. You have seen that
this new industry is not an unexpected gift fallen from the
heavens, but that in order to complete the task the intellectual
labour and the industry of many men had to be co-ordinated,
in an organised attempt to attain a definite object, for a number
of years, and throughout a considerable period when success
could by no means be regarded as certain. The pre-requisites
for practical indigo synthesis were supplied by the results of
long years of scientific labour. All the expedients of an ad-
vanced art were at command, and it is to the wide knowledge, to
the industry, to the energy, and to the faithfulness to duty which
characterise our German chemists that the final completion of
the work is due, a work of which we wish that it may signify an
advance in civilisation, and which we hope will be an honour to
the German chemical industry and a blessing to our country.

THE INDIGO CRISIS 219

OTHER OPINIONS

In a recent lecture before the Society of Arts, 1 Professor
Meldola discussed the various synthetical processes for the
manufacture of indigo, and more especially the manufacture of
" indigo pure " by the Badische Aniline Co.

With regard to the all-important point of cost of production,
Professor Meldola offers the following remarks : " Naphthalene
is the hydrocarbon which exists in coal tar to a larger extent than
any other. The average quantity is about 8 per cent., and there
is any amount of it to be had. The whole of the naphthalene in
tar is not at present extracted, the chief supply being furnished
by the middle or carbolic acid fraction. Mr T. Wilton, of the
Gaslight and Coke Co., states that that company produces about
19^- million gallons of tar annually. This company alone would
thus be able to supply over 15 million pounds of naphthalene
per annum. The purified hydrocarbon has a present market
value of 18, los. per ton, which is less than one penny per
pound. From an estimate supplied by Mr Charles Tyrer, of
Thomas Tyrer & Co., it appears that technical chloracetic acid
might probably be made at about is. id. per pound. As regards
the supply of naphthalene, it has been suggested that the pro-
duction from coal tar would be insufficient to meet the demand,
supposing that all the indigo now required were made syntheti-
cally." Figures given by Dr Brunck refute this statement.
(See page 212.)

It may be added also that coal tar is not the only source of
naphthalene, since a considerable quantity of this hydrocarbon
is contained in coke-oven tar. Moreover, petroleum may be
looked upon as a potential source of naphthalene, since the
crude naphtha, consisting chiefly of heptane and octane, on
decomposition by heat, gives a mixture of hydrocarbons con-
taining, according to Worstall and Burwell, 2 12*5 parts benzene,
3 parts toluene, 3 parts xylene, and 3*6 parts naphthalene for
100 parts naphtha.

With respect to the probabilities of the issue of the conflict
between natural and synthetic indigo, Professor Meldola, while
not regarding the cause of the indigo planters as a forlorn one,

1 Jour. Soc. Arts, iQth April 1901.

2 Amer. C hem. Jour., 1897, x. 815.

220 THE BRITISH COAL-TAR INDUSTRY

considers the outlook as gloomy, in view of the probability of
the Badische process being still further perfected and cheapened. 1

The magnitude of the operations of the large German colour
works has often been the subject of remark in these columns,
but their remarkable growth and the unbounded enterprise with
which they are conducted is very succinctly put in the following
paragraph from Professor Meldola's lecture :

" The factory at Ludwigshafen employs 148 scientific chemists,
75 engineers and technical experts, and 303 members of the
mercantile staff. In 1865 they commenced with 30 workmen,
and they now employ 6000. The consumption of coal is about
243,000 tons per annum. Water is supplied to the factory to
the extent of 20,000,000 cubic metres (4,400,000,000 gallons)
annually ; they make 12,000,000 kilograms (11,400 tons) of ice,
and 12,000,000 cubic metres (420,000,000 cubic feet) of coal
gas in the course of a year. 102 boilers supply steam, which
serves for heating purposes and for driving 253 steam engines.
The factory comprises an area of 206 hectares (510 acres), of
which 317,429 square metres (378,000 square yards) are built
upon."

In October of last year a Commission was appointed by the
Government of India to inquire into the condition of the sugar
and indigo industries, and their report, which has already been
issued, is reviewed in the Times of I5th April 1901. It is there
stated that the average acreage in India under indigo during the
five years 1893-98 was 1,406,000 acres, but in 1899 it was only
1,027,000 acres, and in 1900, 964,000 acres. In 1895-96 the
exports amounted to 187,000 cwts., but steadily declined to
1 1 1,000 cwts. in 1899-1900. This was partly due to unfavour-
able seasons ; but in the past experience of the trade, a low output
was always accompanied by an enhanced price ; whereas, in the
period referred to, the price in the poor years did not show the
same recovery, and the Commissioners conclude that it is reason-
able to anticipate that the competition of synthetic indigo will
prevent any future increase in the price of vegetable indigo,
and that any further reduction in price would be ruinous to the
planters in a bad season.

On the other hand, the planters, who take a more sanguine
view than the Commissioners, consider that by improved culti-

1 An interesting discussion of this point will be found in a paper by
Dr Levinstein (see Jour. Soc. Dyers and Colourists, 1901, p. 138).

THE INDIGO CRISIS 221

vation and mode of extraction and manufacture, a greatly increased
yield will enable them to place a much improved article on the
market at a cheaper rate. This side of the question is well
argued in Mr Rawson's paper, read before a meeting of planters
and merchants in Calcutta, and abstracted in the Journal of the
Society of Dyers and Co tourists (1901, p. 103).

Under the title of " The Downfall of Natural Indigo," Pro-
fessor Armstrong, on 1 5th April, published a long letter in the Times
discussing Dr Brunck's lecture. He takes it pretty much for
granted that the indigo industry is doomed to rapid extinction,
and makes this a text for a vigorous attack on the supineness of
English business men in regard to the adoption of scientific
methods and scientific assistance.

In a letter to Nature on " Indigo and Sugar," Dr F. Molwo
Perkin also pertinently asks, in reference to the above-quoted
figures of the staff at the Badische works, if there "are 148
scientific chemists employed by manufacturers in the whole of
the United Kingdom ? "

The present crisis in the indigo industry may possibly benefit
others indirectly by inducing them to take advantage, more fully
than has been the case in the past, of scientific, and therefore
rational and economical, methods of manufacture.

XIII. : 1902

APPLIED CHEMISTRY, ENGLISH
AND FOREIGN

BY SIR J. DEWAR, M.A., LL.D., D.Sc., F.R.S.
(Abstract from Presidential Address, British Association, Belfast, 1902)

THE diplomatic and consular reports published from time to
time by the Foreign Office are usually too belated to be of much
use to business men, but they sometimes contain information
concerning what is done in foreign countries which affords food
for reflection. One of these reports, issued a year ago, gives a
very good account of the German arrangements and provisions
for scientific training, and of the enormous commercial demand
for the services of men who have passed successfully through the
universities and Technical High Schools, as well as of the wealth
that has accrued to Germany through the systematic application
of scientific proficiency to the ordinary business of life.

Taking these points in their order, I have thought it a matter
of great interest to obtain a comparative view of chemical equip-
ment in this country and in Germany, and I am indebted to
Professor Henderson of Glasgow, who last year became the
secretary of a committee of this Association of which Professor
Armstrong is chairman, for statistics referring to this country,
which enable a comparison to be broadly made. The author of
the consular report estimates that in 1901 there were 4500
trained chemists employed in German works, the number having
risen to this point from 1700 employed twenty-five years earlier.
It is difficult to give perfectly accurate figures for this country,
but a liberal estimate places the number of works chemists at
1500, while at the very outside it cannot be put higher than
somewhere between 1500 and 2000. In other words, we cannot

222

APPLIED CHEMISTRY, ENGLISH AND FOREIGN 223

show in the United Kingdom, notwithstanding the immense
range of the chemical industries in which we once stood promi-
nent, more than one-third of the professional staff employed in
Germany. It may perhaps be thought or hoped that we make
up in quality for our defect in quantity, but unfortunately this is
not the case. On the contrary, the German chemists are, on the
average, as superior in technical training and acquirements as
they are numerically. Details are given in the report of the
training of 633 chemists employed in German works. Of these,
69 per cent, hold the degree of Ph.D., about 10 per cent, hold
the diploma of a Technical High School, and about 5 per cent,
hold both qualifications. That is to say, 84 per cent, have
received a thoroughly systematic and complete chemical training,
and 74 per cent, of these add the advantages of a university
career. Compare with this the information furnished by 500
chemists in British works. Of these only 21 per cent, are
graduates, whilst about 10 per cent, hold the diploma of a college.
Putting the case as high as we can, and ignoring the more
practical and thorough training of the German universities, which
give their degrees for work done, and not for questions asked
and answered on paper, we have only 3 1 per cent, of systematic-
ally trained chemists against 84 per cent, in German works. It
ought to be mentioned that about 2 1 per cent, of the 500 are
Fellows or Associates of the Institute of Chemistry, whatever
that may amount to in practice, but of these a very large number
have already been accounted for under the heads of graduates
and holders of diplomas. These figures, which I suspect are
much too favourable on the British side, unmistakably point to
the prevalence among employers in this country of the antiquated
adherence to rule of thumb, which is at the root of much of the
backwardness we have to deplore. It hardly needs to be pointed
out to such an audience as the present that chemists who are
neither graduates of a university, nor holders of a diploma from
a technical college, may be competent to carry on existing
processes according to traditional methods, but are very unlikely
to effect substantial improvements, or to invent new and more
efficient processes. I am very far from denying that here and
there an individual may be found whose exceptional ability
enables him to triumph over all defects of training. But in all
educational matters it is the average man whom we have to
consider, and the average ability which we have to develop.

224 THE BRITISH COAL-TAR INDUSTRY

Now, to take the second point the actual money value of the
industries carried on in Germany by an army of workers both
quantitatively and qualitatively so superior to our own. The
consular report estimates the whole value of German chemical
industries at not less than fifty millions sterling per annum.
These industries have sprung up within the last seventy years, and
have received enormous expansion during the last thirty. They
are, moreover, very largely founded upon basic discoveries made
by English chemists, but never properly appreciated or scientific-
ally developed in the land of their birth. I will place before you
some figures showing the growth of a single firm engaged in a
single one of these industries the utilisation of coal tar for the
production of drugs, perfumes, and colouring matters of every
conceivable shade. The firm of Friedrich Bayer & Co. employed,
in 1875, 119 workmen. The number has more than doubled
itself every five years, and in May of this year that firm employed
5000 workmen, 160 chemists, 260 engineers and mechanics, and
680 clerks. For many years past it has regularly paid 18 per
cent, on the ordinary shares, which this year has risen to 20 per
cent. ; and in addition, in common with other and even larger
concerns in the same industry, has paid out of profits for immense
extensions usually charged to capital account. There is one of
these factories, the works and plant of which stand in the books
at ; i, 500,000, while the money actually sunk in them approaches
to 5,000,000. In other words, the practical monopoly enjoyed
by the German manufacturers enables them to exact huge profits
from the rest of the world, and to establish a position which,
financially as well as scientifically, is almost unassailable. I must
repeat that the fundamental discoveries upon which this gigantic
industry is built were made in this country, and were practically
developed to a certain extent by their authors. But in spite of
the abundance and cheapness of the raw material, and in spite of
the evidence that it could be most remuneratively worked up,
these men founded no school and had practically no successors.
The colours they made were driven out of the field by newer and
better colours made from their stuff by the development of their
ideas, but these improved colours were made in Germany and
not in England. Now, what is the explanation of this extra-
ordinary and disastrous phenomenon ? I give it in a word want
of education. We had the material in abundance when other
nations had comparatively little. We had the capital, and we

APPLIED CHEMISTRY, ENGLISH AND FOREIGN 225

had the brains, for we originated the whole thing. But we did
not possess the diffused education without which the ideas of
men of genius cannot fructify beyond the limited scope of an
individual. I am aware that our patent laws are sometimes held
responsible. Well, they are a contributory cause ; but it must
be remembered that other nations with patent laws as protective
as could be desired have not developed the colour industry.
The patent laws have only contributed in a secondary degree,
and if the patent laws have been bad the reason for their badness
is again want of education. Make them as bad as you choose,
and you only prove that the men who made them, and the public
whom these men try to please, were misled by theories instead
of being conversant with fact and logic. But the root of the
mischief is not in the patent laws or in any legislation whatever.
It is in the want of education among our so-called educated
classes, and secondarily among the workmen on whom these
depend. It is in the abundance of men of ordinary plodding
ability, thoroughly trained and methodically directed, that
Germany at present has so commanding an advantage. It is the
failure of our schools to turn out, and of our manufacturers to
demand, men of this kind, which explains our loss of some
valuable industries and our precarious hold upon others. Let
no one imagine for a moment that this deficiency can be remedied
by any amount of that technical training which is now the
fashionable nostrum. It is an excellent thing, no doubt, but it
must rest upon a foundation of general training. Mental habits
are formed for good or evil long before men go to the technical
schools. We have to begin at the beginning : we have to train
the population from the first to think correctly and logically, to
deal at first hand with facts, and to evolve, each one for himself,
the solution of a problem put before him, instead of learning by
rote the solution given by somebody else. There are plenty of
chemists turned out, even by our universities, who would be of
no use to Bayer & Co. They are chock-full of formulae, they
can recite theories, and they know text-books by heart ; but put
them to solve a new problem, freshly arisen in the laboratory,
and you will find that their learning is all dead. It has not
become a vital part of their mental equipment, and they are
floored by the first emergence of the unexpected. The men who
escape this mental barrenness are men who were somehow or
other taught to think long before they went to the university.

226 THE BRITISH COAL-TAR INDUSTRY

To my mind, the really appalling thing is not that the Germans
have seized this or the other industry, or even that they may
have seized upon a dozen industries. It is that the German
population has reached a point of general training and specialised
equipment which it will take us two generations of hard and
intelligently directed educational work to attain. It is that
Germany possesses a national weapon of precision which must
give her an enormous initial advantage in any and every contest
depending upon disciplined and methodised intellect.

XIV.: 1903

THE RELATION BETWEEN SCIENTIFIC
RESEARCH AND CHEMICAL INDUSTRY

BY PROFESSOR R. MELDOLA, F.R.S.

(Lecture delivered at the Oxford Summer Meeting, August 1903)

THIS lecture deals in a general manner with the interdependence of
science and industry, using as illustrations the manufacture of optical
glass, fertilisers, the fermentation industries, and the coal-tar colour
industry. The fundamental necessity of both pure and technical
research is insisted upon.

227

XV.: 1905

THE HISTORY OF THE COAL-TAR COLOUR
INDUSTRY BETWEEN 1870 AND 1885

BY PROFESSOR R. MELDOLA, F.R.S.

(Abstract of a Memorandum which accompanies the Report of the
Committee on Industrial Alcohol : Journal of the Society of Dyers
and Colourists^ 1905, p. 175)

THE chief dyes made in England during the period 1870-1885
were magenta, aniline blue, its sulpho acids and by-products,
Hofmann violets, iodine green, Bismarck brown, aniline yellow,
indulines, phosphine, safranine, chrysoidine, naphthol orange
and other azo dyes, picric acid, Manchester yellow, alizarin.
During the same period the dyes made abroad, in addition to the
above colouring matters, were methyl violet, crystal violet, etc. ;
methylene blue, acid magenta, malachite green, brilliant green,
Victoria blue, night blue, auramine, etc. ; monazo colours from
homologues of aniline and sulpho acids of naphthols, disazo
colours of various kinds, and especially the direct cotton dyes ;
oxazines, such as gallocyanine, etc. ; phthalems. The decline in
our coal-tar colour industry began about the year 1880. In 1886
about 90 per cent, of the dyes used in England were of foreign
manufacture. The statement that the industry has been driven
out of the country for want of duty-free spirit is quite erroneous,
because it can be shown that during the earlier years the question
of the price of alcohol was quite a subordinate one. Our supre-
macy had, in fact, been lost long before the price of alcohol, as
compared with the prices of the finished products, had become a
matter of any great importance. The cost of alcohol as a factor
in determining the cost price of dyestuffs could be left out of
consideration altogether, but the further back we go into the
history of the industry, the less important does the price of

228

INFLUENCE OF SPIRIT DUTY 229

alcohol become. It is perhaps fair to say that during the period
anterior to 1870 it was practically negligible, and during the
period 1870-1880 it was of quite minor consideration certainly
the relative cost of alcohol at that period does not warrant the
belief that our loss of the manufacture had anything to do with
the spirit duties.

Beginning with the home list. Hofmann's violet and iodine
green are the only dyes into the composition of which the alcohol
radical (methyl) enters. They were made from rosaniline and
methyl iodide, which was then made from wood naphtha, and
was not taxed. None of the other dyes on the list required
alcohol in any quantity excepting aniline blue, in which case it
was used as a solvent. Methylated spirit was used, and after-
wards recovered with little loss. The conclusion seems to be
inevitable that the spirit duty had nothing whatever to do with
the matter. Hofmann's violet is now extinct, but aniline blue
and its derivatives are still important products, but we have lost
our supremacy, and by far the largest proportion of these dye-
stuffs now on the market is of foreign manufacture. We lost
ground, therefore, in a branch of manufacture which was supreme
in this country, and for which, although alcohols were required,
no excuse for our decadence could possibly have been based on
the plea that the spirit duties were to blame. Alizarin, one of
the most important products, was at one time manufactured by
Perkin's firm and their successors, and afterwards by the British
Alizarin Company. Although the raw material anthracene is
produced in large quantities in this country, the manufacture of
alizarin here became practically extinct for many years, although
it is now being restored. Whatever may have been the causes
of our temporary decadence in this case, the success of our com-
petitors cannot possibly be attributed to their command of duty-
free spirit, because alcohol is not used.

The proximate causes of our decadence, so far as these are
concerned with the alcohol question, may be said to be the dis-
covery of new colouring matters and processes by foreign chemists,
and the improvement of the processes for manufacturing the pro-
ducts already in existence. The want of duty-free spirit in regard
to these improved processes cannot have been great during the
period 1 870-1 885. The introduction of new dyestuffs is, however,
of fundamental importance. Coming to the foreign list, with the
exception of the oxazines all these compounds were discovered by

2 3 o THE BRITISH COAL-TAR INDUSTRY

foreign chemists. The author discovered the first member of the
oxazines in 1879, ^ ut ^ was not manufactured here until many
years later, and then not in the factory where it was discovered.
The manufacture was at once taken up in Germany. In this case,
although one of the raw materials contains the radical of methyl
alcohol, the duty upon pure wood spirit had nothing to do with
the transference of the manufacture of this colouring matter.

The introduction in 1866 of methyl violet (Poirrier) first
created a demand for dimethylaniline which contains the radical
methyl. Dimethylaniline was also necessary for methylene blue
(1876), malachite green (1878), crystal violet, Victoria blue, and
auramine (1883). Diethylaniline was necessary for brilliant
green (1879) and night blue (1883). At the time, therefore,
when the decline of the industry had seriously set in, with the
exception of methyl violet, none of the dyestufFs on the foreign
list were made in this country, and the dimethyl and diethyl-
anilines were being manufactured abroad for the manufacture of
dyes discovered by foreign chemists. The effect of these newer
colouring matters upon the dyestufFs being made here at the time
of their introduction is evidently connected with the loss of our
supremacy. Hofmann's violet was gradually replaced by methyl
violet, and iodine green, which, however, was only produced in
limited quantity, was rapidly extinguished by the malachite green
group. Victoria blue and methylene blue did not seriously inter-
fere with our aniline blue group, as they fulfilled a different
function in the tinctorial industry. In 1880, therefore, the only
one of our dyestuffs directly affected by the introduction of di-
methylaniline was Hofmann's violet. To what extent did the
command of duty-free alcohol give our competitors an advantage
in the manufacture of such dyestuffs as methyl violet, methylene
blue, and malachite green ? They were all foreign patents. When
methyl violet was made here the patent had lapsed, the dimethyl-
aniline being imported from abroad, as its manufacture was not
taken up here down to 1885, in spite of Government concessions
in regard to duty-free alcohol when the point was first raised in
1880. Dimethylaniline can be made by heating aniline hydro-
chloride with pure methyl alcohol in autoclaves which were used
on the Continent at this time, but not here. It can also be made
by the action of methyl chloride, obtained in 1878 from tri-
methylamine, a beet sugar by-product, upon aniline. It there-
fore could not be produced cheaply in England. At that period

INFLUENCE OF SPIRIT DUTY 231

all the coal-tar colours were commanding such prices that the cost
of the alcohol was insignificant as compared with the margin of
profit. Methyl violet displaced Hofmann's violet because it is
made directly from its raw material, whereas Hofmann's violet
has to go through several reactions, including the use of methyl-
iodide.

With the exception of methyl violet, every one of the new
products necessitated the manufacture of some new raw material,
such as benzoic aldehyde for malachite green, phenylnaphthyl-
amine for Victoria blue, tolylnaphthylamine for night blue, etc.
None of these raw materials required alcohol for their production.
The difference in cost between the dyestuffs made from duty-paid
or duty-free alcohol, as compared with the margin of profit, was
quite insignificant. During the period dealt with our industry
was seriously affected by the inventive activity of the foreign
manufacturers, but its decline cannot be attributed to their having
the use of duty-free alcohol.

The conditions have changed since 1885. Prices were falling
from 1880, and the margin of profit becoming smaller. The
difference in the cost of manufacture due to the use of duty-free
spirit would now bear a very much larger ratio to the margin of
profit, and whereas this difference was formerly for all practical
purposes a negligible quantity, it may now have become a serious
factor. For this reason the author's opinion is that it is desirable
that our chemical manufacturers should be placed upon the same
footing as their foreign competitors so far as concerns the use of
duty-free alcohol.

XVI.: 1906

NOTE ON THE PERKIN JUBILEE

To mark the fiftieth anniversary of the discovery of the first
coal-tar dyestuff and as a personal tribute to Sir William Perkin,
an international meeting was held at the Royal Institution,
London, on Thursday, 26th July 1906.

Special representatives were present from Germany, Austria,
France, Belgium, Holland, Switzerland, Italy, Denmark, Russia,
and the United States, in addition to a very representative
gathering of British chemists, and a large number of addresses
were presented to Sir William Perkin from British and Foreign
chemical and other societies, universities, etc.

A further celebration was held in the autumn of the same year
when Sir William Perkin visited the United States.

Many interesting references dealing with the history and
development of the coal-tar colour industry will be found in the
speeches delivered and addresses presented on the occasion of
the London and New York celebrations, but they cannot usefully
be summarised here.

A full report of the whole of the proceedings was published
in book form by the Perkin Memorial Committee and issued by
The Times Office, London.

232

XVII. : I 9 o8
PERKIN OBITUARY NOTICE

BY PROFESSOR R. MELDOLA, F.R.S.

(Journal of the Chemical Society^ 1908, p. 2214)

THIS lecture constitutes the Obituary Notice of Sir William Perkin
contributed to the Chemical Society. It gives a complete review of
Perkin s life and work, but the points of especial interest from the
point of view of the present work are largely covered by the following
papers :

Perkin : " The Colouring Matters produced from Coal-tar"

t; 75-
Perkin : " The Origin of the Coal-tar Colour Industry"

p. 141.

Meldola : " The Founding of the Coal-tar Colour Industry"
P- 234.

2 33

XVIII. : I 9 o8

THE FOUNDING OF THE COAL-TAR
COLOUR INDUSTRY

BY PROFESSOR R. MELDOLA, F.R.S.

(Presidential Address to the Society of Dyers and Colourists, 1908 :
Journal of the Society of Dyers and Colour ists^ 1908, p. 95)

THE late President of the Society, Sir William Henry Perkin,
passed away on i/j-th July 1907, in the sixty-ninth year of his
age, and in the zenith of his fame. It would be superfluous to
retell here the story of the discovery of mauve, or the influence
of that discovery upon the tinctorial industries. The great inter-
national gathering of 1906, which will still be fresh in your
memories, furnished ample opportunity for reviewing the life-
work of the man whom the nations had assembled to honour,
and he himself gave a very full account of his connection with
the industry. This is all recorded in the official report of the
jubilee meeting published by the Memorial Committee. Some
interesting reminiscences were also given by Sir Robert Pullar
and others at last year's annual dinner, at which Sir William
Perkin presided, and of which a full report was published in the
April number of the Journal. I have, moreover, written an
obituary notice of him for the Royal Society, and in this I have
endeavoured to do justice to his scientific work and personal
character. It cannot but be a source of the greatest satisfaction
to us all the one mitigating circumstance that lightens our
sorrow at his loss that he fell from our ranks not unrecognised,
as is the fate of so many of our scientific pioneers in this country,
but laden with freshly bestowed honours, and with the full
knowledge that his labours had won lasting gratitude in the two
great spheres of human activity, Science and Industry. Further-

234

THE FOUNDING OF THE INDUSTRY 235

more, it cannot but be a gratifying memory to us that our
Society throughout its future history will be able to point to the
name of Perkin on the roll of its past Presidents. He died in
our service, and one of his last acts in connection with this
Society was to accompany the deputation to the Dyers' Company
in order to plead with that worshipful body for assistance in
founding prizes to be awarded by our Society for the solution of
technical problems connected with the industry.

On the present occasion our annual gathering, saddened by
the loss of our late President, will be made memorable by its
marking the first award of the Perkin medal, founded in 1906
in celebration of the jubilee of the discovery and manufacture
of the first coal-tar colouring matter. No more fitting tribute
to the memory of my distinguished predecessor could be paid
than that his successor in this chair should endeavour to enable
you to realise the full measure of our indebtedness to him. I
propose therefore to invite you to take with me a retrospective
glance into the conditions, scientific and industrial, antecedent to
that accidental discovery of 1856, which marked the beginning
of the modern revolution in all tinctorial methods. Let us con-
sider, in the first place, the state of affairs with respect to the raw
materials required for the manufacture of mauve. These were
benzene, nitrobenzene, and aniline.

Benzene, as you are aware, was discovered by Michael Faraday,
in 1825, as a component of the liquid obtained by the compression
of oil-gas. Twenty years later Hofmann found this hydrocarbon
in coal-tar, and proved its presence by preparing from it nitro-
benzene and aniline, the latter being identified by the usual tests.
The occurrence of benzene in coal-tar was thus known in 1 845,
and in 1 848 one of Hofmann's brilliant young students at the
Royal College of Chemistry, Charles Blachford Mansfield, at the
instigation of his illustrious master, undertook a systematic study
of coal-tar, with a view to the isolation and identification more
especially of the " neutral liquid oils," of which he tells us in his
paper published by the Chemical Society in 1 849 we had at that
time " no precise information." When Mansfield took up this
work a few definite compounds were known to exist in this tar,
notably naphthalene, which had been isolated by Garden in 1820,
and certain acid and basic substances, such as phenol (carbolic
acid), aniline (kyanol), quinoline (leucol or leucoline), and pyrole,
all of which had been isolated by Runge in 1834. Anthracene,

236 THE BRITISH COAL-TAR INDUSTRY

under the name of " paranaphthaline," was isolated by Dumas
and Laurent in 1833, although it is now known that their original
analysis, which assigned to this hydrocarbon 15 atoms of carbon,
was erroneous. Chrysene and pyrene had also been indicated,
but only superficially studied by Laurent in 1837. To the basic
constituents picoline was added in 1846 by Anderson.

Such was the state of knowledge when Hofmann set Mansfield
to work upon the coal-tar hydrocarbons. The paper embodying
his results is entitled " Researches on Coal Tar, Part I.," x and
now, nearly sixty years after its publication, it can still be read with
interest and profit. Its contents have become historic in con-
nection with the colour industry, and must rank with Runge's
celebrated papers of i834 2 among the most important con-
tributions to tar chemistry that preceded the foundation of that
industry.

Even at the time of Mansfield's work no coal-tar hydrocarbon
had been utilised as a source of other chemical compounds,
tinctorial or otherwise, and he himself, in describing the practical
applications of benzene, refers only to its use as a solvent or an
illuminant. Perkin's discovery thus created a demand for this
hydrocarbon as a raw material in a new industry on a scale never
before contemplated. Mansfield's experiments had prepared
the way, but there had been no demand for benzene, and the
tar distillers could not at first supply it in quantity or in a
sufficient state of purity. It is of interest to know that the
first supply of this material used by Perkin came from the Scotch
tar distillery of Messrs Miller & Co., of Glasgow.

Then came the difficulties connected with the nitration and
the reduction of the nitrobenzene to aniline. Here again
Mansfield had played the part of a pioneer, but his process
was impracticable on the scale now required. Moreover, it
was too costly, for it must be borne in mind that the new dye
had to compete with the existing vegetable colouring matters,
and on I2th June 1856, Messrs Pullar, of Perth, who had
been testing the dyeing properties of mauve, had reported to

1 Chem. Soc. Quart. Jour., 1849, vol. i. p. 244. He gave a general
account of his work at a Friday evening discourse at the Royal Institution
on 2yth April 1849, which was published as a brochure, entitled "Benzole:
its Nature and Utility."

2 Poggendorff's A nnalen, vol. xxxi. pp. 65 and 513; vol. xxxii. pp. 308
and 328.

THE FOUNDING OF THE INDUSTRY 237

Perkin that the discovery was a valuable one provided it did not
" make the goods too expensive." It is needless to say that
nitric acid of the strength used by Mansfield would have been
a very costly material in 1856. In fact, nitric acid of sufficient
strength to nitrate benzene could not be obtained in quantity
at that period, and Perkin had to devise apparatus for nitrating
with a mixture of sulphuric acid and sodium nitrate. His
resourcefulness is well revealed by this passage quoted from his
Hofmann Memorial Lecture in 1876 : "At this time neither
I nor my friends had seen the inside of a chemical works, and
whatever knowledge I had was obtained from books. This,
however, was not so serious a drawback as at first it might
appear to be, as the kind of apparatus required, and the character
of the operations to be performed, were so entirely different from
any in use that there was but little to copy from.

" In commencing this manufacture it was absolutely neces-
sary to proceed tentatively, as most of the operations required
new kinds of apparatus to be devised and tried before more
could be ordered to carry out the work on any scale " (see
p. 153, ante).

After the manufacture of mauve had been started the
demand for the new dyestufF increased to such an extent that
the resources of the Greenford factory were taxed to their
utmost, and the assistance of another firm had to be called in
for supplying raw materials. That firm was Simpson, Maule &
Nicholson, whose factory was at Locksfields, in the south of
London. The Nicholson of the firm was that pupil of Hofmann's
already referred to as having been a co-worker with Mansfield,
and, under his energetic management, they not only supplied
the firm of Perkin & Sons with some of the raw materials
required, but later they also entered the colour industry, and
in 1865 established the Atlas Works at Hackney Wick, the
firm being transferred in 1868 to Messrs Brooke, Simpson &
Spiller. Mr William Spiller, formerly of this latter firm, has
told me that he well remembers the early stages in the
manufacture of nitrobenzene by their predecessors at Locksfields,
where he was then working in association with the late
Mr E. C. Nicholson. The nitration was carried out in large
glass " boltheads " arranged in series, as they had not then
discovered that cast-iron vessels could be used. The scale of
working was quite small as compared with the modern output

238 THE BRITISH COAL-TAR INDUSTRY

from a large nitrating still, and they experienced the difficulty
referred to by Perkin of obtaining a supply of pure benzene.
The operation also was somewhat capricious, owing to the want
of uniformity in the quality of the commercial " benzole,"
and to the absence of mechanical stirring. The cheapening
of the process by the introduction of cast-iron stills with
mechanical stirring gear did not take place until some time after
the manufacture of mauve had been commenced in 1857. The
plant in use was described and figured by Perkin in his Cantor
Lectures, delivered before the Society of Arts in 1868, and has
since been refigured in many works on technology, as it is
practically the same in principle as that now generally in use. 1

The next step, the reduction to aniline, had also to be
worked out on the manufacturing scale. The laboratory method
then generally in use was Zinin's, viz. sulphuretted hydrogen
in presence of ammonia, a process obviously impracticable on
the large scale. The use of metals, such as tin or zinc, in
combination with acids, would have been both costly and
unmanageable. Fortunately, however, Bechamp in 1854 had
found that iron and acetic acid could be used for reducing
nitro compounds, and Perkin, who had been familiarised with
this process in Hofmann's laboratory, applied it successfully for
the manufacture of aniline. 2 That this was a task of considerable
difficulty can be readily understood by those who are familiar
with the violence of such " reducing " processes, unless properly
controlled. It is, in fact, known that at first serious attempts
were made to extract the minute quantity of aniline contained
in the coal-tar oils directly by acid washing a process which,
it is needless to say, had soon to be abandoned on account of
its cost and the impure state of the product. In the manufacture
of aniline from nitrobenzene the firm of Simpson, Maule &
Nicholson also co-operated with Perkin & Sons, and Mr
William Spiller has given me a graphic description of their

1 A workman, James Underwood, in the employment of Simpson, Maule
& Nicholson, at Locksfields, during the early years of the colour industry,
also remembers this manufacture of nitrobenzene in boltheads and the
development to cast-iron stills. This last improvement is generally attri-
buted to E. C. Nicholson. A figure of the earliest form of (horizontal)
still was given by Perkin in his Cantor Lectures above referred to.

2 " Had it not been for this discovery the coal-tar colour industry could
not have been started." W. H. Perkin, Hofmann Memorial Lecture (see
p. 153, ante).

THE FOUNDING OF THE INDUSTRY 239

early work at Locksfields when starting this branch of the
industry. The reduction was carried out in iron vessels with
removable still-heads, the vessel being at first uncovered, and
the materials, nitrobenzene, iron turnings, and acetic acid, simply
stirred up by a rod until the reaction showed signs of starting.
The still-head was then immediately clapped on, and a workman
mounted guard with water-hose ready to play over the still if
the contents gave signs of boiling too violently. The cost of
the acetic acid was a considerable item at that time, and they
had to make their own acid by heating sodium acetate with
sulphuric acid. It was soon found that hydrochloric acid could
be used instead of acetic acid, and the introduction of stills
with mechanical stirrers put this branch of the manufacture on
a sure basis. It is perhaps hardly necessary to point out that
the "aniline" of that period was a mixture of homologues, and
very impure from the modern point of view.

And so the manufacture of the first of the "synthetic
dyestuffs " was started at Greenford Green towards the end of
the year 1857, and the genius of the founder had ample scope
for exercise. Let it be borne in mind that the raw product
obtained by oxidising crude aniline with sulphuric acid and
potassium dichromate was what would now be called a " resinous
mess." Processes for its purification had to be devised, and
here again the resourcefulness of Perkin becomes manifest.
With that true scientific spirit which dominated all his work
the investigation of his products and processes was always kept
going. At first the crude product was collected on filters and
washed with water to remove excess of aniline sulphate, then
dried and powdered, and extracted with coal-tar " naphtha "
until free from resinous impurities, then dried again and
extracted with methylated spirit, and the filtered solution distilled
until the dyestufF separated out. This method of purification
was afterwards improved and cheapened by the omission of the
naphtha treatment, as it was found that diluted methylated
spirit extracted the colouring matter directly, and left the resin
undissolved. The process was finally simplified by boiling out
the colouring matter with water alone, and precipitating with an
alkali so as to obtain the free base, which was then converted
into acetate for use by the dyers.

The discovery and manufacture of mauve, with its train of
consequences, must be regarded as constituting but a portion of

2 4 o THE BRITISH COAL-TAR INDUSTRY

Perkin's claim to our gratitude. In starting upon this work he
had, against the advice of his illustrious master, Hofmann,
broken away from the path of pure science and entered a field
in which he was a novice. His whole future was bound up with
the success of the undertaking, for his father had placed nearly
his entire capital in the venture in order to establish the factory
at Greenford Green. There was evidently something more to
be done besides placing the new dyestuff on the market. The
dyers and printers had to be convinced of its merits and taught
how to use it. This task, by no means a light one, had also to
be undertaken by Perkin, who, up to that time, had never been
brought into contact with the tinctorial industries. It has fre-
quently been mentioned that Messrs Pullar, of Perth, were the
first to give encouragement to the young inventor so far as
concerned the dyeing properties of mauve. At their instigation
it was tried for silk dyeing by Thomas Keith, silk dyer, of
Bethnal Green, London, and he also reported favourably. But,
as is generally the case with new departures, the step from the
experimental to the practical scale was not made without en-
countering difficulties. It was found that on the large scale
the dye " took on " unevenly, and caused a patchy appearance,
so that a restraining material had to be added to the bath. The
use of the soap bath for silk dyeing was the outcome of Perkin's
association with a practical dyer, and Keith's dyehouse was the
first in which mauve was used on the industrial scale.

Then with respect to wool and cotton dyeing, the same
pioneering work had to be done. Perkin has told us that he
and Mr (now Sir) Robert Pullar had independently discovered
the use of tannin and a metallic oxide as a mordant for cotton
dyeing, and, in conjunction with Alexander Schultz, he had
introduced the " insoluble arsenite of alumina " as a mordant.
The calico printers in this country did not at first take kindly to
the new colouring matter, and Perkin has often told me that
the impetus to this most important application of his discovery
came from France. It appears that, owing to some technical
oversight, the French patent was ineffective, and the French
manufacturers accordingly began making the new dyestuff them-
selves. It was in France, in fact, that the term " mauve " was
given. With the well-known skill of the French calico printers
beautiful designs in mauve were produced and sent over to this
country, and this was more effective than any other cause in

THE FOUNDING OF THE INDUSTRY 241

hastening the use of the dye for this purpose over here. Had
it not been for this stimulus the success of the new factory would
have been doubtful, for Messrs Pullar had reported to Perkin that,
in their opinion, unless the new dye could be used by the printers
it would be questionable whether " it would be wise to erect works
for the quantity dyers alone will require." l In summing up this
part of his experience Perkin stated in 1896 :

" Before the aniline purple could be introduced for dyeing
woollen and mixed fabrics, some weeks were also spent at
Bradford in rinding out suitable methods of applying it.

" Thus it will be seen that, in the case of this new colouring
matter, not only had the difficulties incident to its manufacture
to be grappled with, and the prejudices of the consumer over-
come, but, owing to the fact that it belonged to a new class
of dyestuffs, a large amount of time had to be devoted to the
study of its applications to dyeing, calico printing, etc. It was,
in fact, all pioneering work clearing the road, as it were, for
the introduction of all colouring matters which followed, all
the processes worked out for dyeing silk, cotton, and wool,
and also for calico printing, afterwards proving suitable for
magenta, Hofmann violet, etc." (Hofmann Memorial Lecture,
loc. cif., p. 609.)

It will be remembered that at our last anniversary dinner,
presided over by Perkin, Sir Robert Pullar gave us some of
his early reminiscences concerning the attitude of the Scotch
calico printers towards the new colouring matter.

The success of the new industry had for its natural con-
sequence the creation of a host of imitators. All kinds of
oxidising agents were tried upon aniline and made the subjects
of rival patents. The departure from the original patent was
in some cases so slight that it is questionable whether in modern
patent legislation the inventor's claim would not be dismissed as
a " colourable imitation." Tabourin and Franc Bros, claimed
aniline hydrochloride instead of sulphate ; Beale and Kirkham
in England, as well as Scheurer-Kestner, Depouilly and Lauth,
Coblentz, and C. Phillips in France, claimed bleaching powder ;

1 " I distinctly remember, the first time I induced a calico printer to
make trials of this colour, that the only report I obtained was that it was too
dear, and it was not until nearly two years afterwards, when French printers
put aniline purple into their patterns, that it began to interest English
printers." Perkin's Cantor Lectures, Society of Arts (see p. 15, ante).

242 THE BRITISH COAL-TAR INDUSTRY

Smith claimed chlorine water, Greville Williams potassium per-
manganate, Kay manganese dioxide, David Price (attached to
the firm of Simpson, Maule & Nicholson) claimed lead
peroxide, Dale and Caro cupric chloride, Stark and Guyot
red prussiate of potash, and so forth. It is needless to point
out that many of the products obtained by these inventors
could not have been Perkin's mauve at all, and, as a matter
of fact, not one of these rival processes was enabled to com-
pete successfully with the original " bichromate " method. The
yield was too small, or the colour too difficult to purify, or
the oxidising agent too expensive, although at that time the
bichromate cost from icd. to nd. per pound. The only one
of these processes which gave a good result was Dale and
Caro's, but even this could not be worked so economically as
the original process.

The introduction of mauve by the founder of and pioneer
in this new development in manufacturing chemistry soon led,
as you are all aware, to the further discovery of coal-tar colouring
matters and to the establishment of other factories. My present
theme centres round Perkin's work in this field, and I do not
propose to enlarge upon the discoveries of others excepting in
so far as they influenced the life of our late President. For
about a decade the manufacturing operations at Greenford were
carried on successfully, and without any fresh discovery of very
great importance, although Perkin's activity in the field of pure
scientific investigation never ceased. Magenta was first made
industrially by Verguin, in France, in 1859, and the firm of
Simpson, Maule & Nicholson soon began to manufacture this
on the large scale by the arsenic acid process as well as other
well-known colouring matters. Such was the development of
the industry that in 1862, the year of the International Exhibition
in London, Hofmann gave a Friday evening discourse at the
Royal Institution, 1 from which it appears that the definite com-
pounds which had been isolated from coal-tar, and which in
Mansfield's lists of 1 848 consisted of thirteen, had then risen to
about forty. It was for that Exhibition that Messrs Simpson,
Maule & Nicholson prepared a crown of magenta crystals
(acetate), which Hofmann exhibited during his lecture, the title
of which was " Mauve and Magenta." The selling price of the
new dyes at that time may be gathered from the circumstance
1 Chemical News, vol. vi. p. 90.

THE FOUNDING OF THE INDUSTRY 243

that the purified solid mauve sold for about the same price as
platinum, weight for weight, and the vat from which the
magenta cc crown " had been crystallised contained a weight of
the acetate of that base valued at j8ooo, the crystals adhering
to the wire framework of the crown being valued at ^roo. 1

The discovery and manufacture of magenta was undoubtedly,
after the production of mauve, the most important contribution
to the industry made during the decade referred to. This dis-
covery did not at first affect Perkin's operations ; mauve still
held its own, and in 1859 Perkin's brother Thomas, the
business man of the establishment, patented on behalf of the
firm a process for making magenta by oxidising crude aniline
with mercuric nitrate. 2 This was an improvement upon the
original stannic chloride process of Verguin, but it was
dangerous, capricious, and expensive, and was very soon dis-
placed by Medlock's arsenic acid process worked by Simpson,
Maule & Nicholson, and also, as the result of a celebrated
lawsuit, by Messrs Read Holliday & Sons, of Huddersfield.
But although Perkin & Sons never made magenta in any
quantity, the introduction of this dyestuff led to new and
necessary developments in their factory. About five years after
the foundation of the Greenford works, Hofmann, who had
then enthusiastically entered the field of colour chemistry, found
that magenta when ethylated or methylated gave rise to
violet colouring matters, the manufacture of which was at once
taken up by Simpson, Maule & Nicholson. 3 Hofmann's violets
and certain phenylated rosanilines, discovered about the same
time by Girard and De Laire, in France, and made here also by
Simpson, Maule & Nicholson, soon began to enter into com-
petition with mauve.

1 Some of the original crystals are now in the possession of Mr William
Spiller. A trade catalogue of the firm of Simpson, Maule & Nicholson,
placed at my disposal by Dr Cain, shows that in 1866 "pure roseine" was
priced at 25. 6d. per oz.

2 " Das Zinnchlorid wird durch das Quecksilbernitrat ersetzt, mit dem
die Fabrikation auch in Deutschland ihre ersten, kraftigen Wurzeln fasst."
H. Caro, JBer., 1892, p. 1031.

3 The manufacture of methyl and ethyl iodide on the large scale was a
remarkable achievement at the time. When I entered the Atlas Works, in
1877, the Hofmann violets were still being manufactured, and the use of
these colouring matters by English dyers continued for more than twenty
years after that date. The violet is priced in the 1866 catalogue of Simpson,
Maule & Nicholson at 35. per oz.

244 THE BRITISH COAL-TAR INDUSTRY

It has not, 1 think, been sufficiently dwelt upon by any of the
historians of the coal-tar colour industry that Perkin' s pioneering
discovery reacted upon itself, for there can be no doubt that the
production of aniline on the large scale led to the discovery of
processes for the manufacture of magenta, and it was the
derivatives of the latter that first began seriously to displace
mauve. The discovery by Lauth of colouring matters such as
methyl violet, formed by the oxidation of the alkylated anilines
and manufactured in France about 1866, brought into the field
other competitors with the original mauve. The newer dyes were
not so fast as mauve, but they were much more brilliant, and
fastness soon gave way to brightness. The practical effect of
these later developments made itself felt in the gradual decline
in the demand for mauve, the use of which soon became very
limited, and finally died out altogether. As a flourishing branch
of the colour industry it may be said that mauve did not com-
plete ten years of its existence. But Perkin was enabled to
keep the Greenford works going successfully in spite of the
adverse influence of the new discoveries and the coming into
existence of other factories. He introduced in 1864 a very
ingenious method for the indirect alkylation of magenta, which
enabled their firm to compete with the other violet colouring
matters then in the market. This method consisted in heating
magenta base with methylated spirit afterwards improved by
substituting methyl alcohol and the compound formed from
turpentine-oil and bromine in the presence of water. This
" brominated turpentine " had long been known to chemists,
and had been investigated by Greville Williams, but had never
before been used for manufacturing purposes. The dyes thus
made were introduced under name of Britannia violet of different
shades of blueness, according to the degree of alkylation. It
was at first thought that they contained the terpene radicle,
although it was afterwards considered that they were of the
same type as, if not identical with, the Hofmann violets, so that
Perkin had really discovered an indirect method of methylation
of a type unknown in chemistry at that time. Perkin's process
was very successful, although he was handicapped by having to
purchase magenta base, which his firm did not manufacture.
But, on the other hand, brominated turpentine was cheaper as an
alkylating agent than the methyl iodide used in the manufacture
of Hofmann violets.

THE FOUNDING OF THE INDUSTRY 24$

I will venture to interpolate here a small experience of my
own, because it is connected with this same department of the
colour industry, and, although the experiments which I am about
to describe were carried out thirty-seven years ago, I have never
had such a favourable opportunity for placing them upon record.
The violet dyes now known to be alkylated rosanilines were at that
time being sold at very high prices, and any new process, i.e.
any process which did not infringe existing patents, would have
been of very great commercial value. As a youth I had just
then entered the colour industry in the service of Messrs
Williams, Thomas & Dower, of the Star Chemical Works,
Brentford. In 1870 it occurred to me, in view of Perkin's
success with brominated turpentine, to try whether the additive
compounds of defines with bromine were equally effective, and
my first experience in manufacturing chemistry was the produc-
tion of ethylene bromide on the large scale. This part of the
process was very successfully carried out, and I have a very
vivid recollection of the pride with which I displayed ethylene
bromide in Winchester quart bottles, the compound being
obtained in almost quantitative yield by passing ethylene from
alcohol and sulphuric acid through bromine in a special form of
apparatus which I devised for this operation. But, alas ! the
next part of the process proved a failure. The ethylene bromide
did react with the magenta base in presence of methyl alcohol,
but the alkylene radicle itself entered the rosaniline molecule
there was no transference of radicle as in Perkin's process, and
the ethylenerosaniline turned out to be an insoluble resin of no
use as a dyestuff. Fuming sulphuric acid might possibly have
saved the situation, but this was before the days of "acid
magenta," and nobody then knew that such compounds could
be sulphonated.

But to return to the Greenford Green factory. After eleven
years' successful working with mauve and certain of its deriva-
tives, the Britannia violets, and a few other dyes which are
given in the subjoined list, a new impetus suddenly came
through the announcement in 1868 that Messrs Graebe and
Liebermann, in Germany, had discovered that alizarin, the
colouring matter of the madder plant, was a derivative of the
coal-tar hydrocarbon] anthracene, and not, as had formerly been
supposed, a derivative of naphthalene. The German chemists
found also that the compound could be prepared from anthracene,

246 THE BRITISH COAL-TAR INDUSTRY

and thus was accomplished the first laboratory synthesis of a
natural colouring matter. 1 may perhaps be allowed to quote the
following passage from my Royal Society obituary notice :

" This discovery had a great influence upon Perkin's career
as an industrial chemist, and may indeed be considered to have
marked a new phase of his activity in this field. There was no
living worker in this country at that time besides Perkin who
so completely combined in himself all the necessary qualifications
for taking advantage of such a discovery. Imbued with the
spirit of his early ambition to produce natural compounds synthe-
tically, with more than a decade's experience as a manufacturer,
with the resources of a factory at his disposal, and, not least,
with special experience of anthracene as the very substance upon
which at Hermann's instigation he commenced his career in
research work, it can readily be understood that Graebe and
Liebermann's results should have appealed to him with special
significance. The first patented process of the German discoverers
was confessedly too costly to hold out much hope of successful
competition with the madder plant, requiring as it did the use
of bromine. Perkin at once realised the importance of cheapen-
ing the process by dispensing with the use of bromine, and
undertook researches with this object. As a result, the following
year (1869) witnessed the introduction of two new methods for
the manufacture of artificial alizarin. In one of these processes
dichloranthracene was the starting-point, and in the other the
sulphonic acid of anthraquinone, the first being of special value
in this country owing to the difficulty of obtaining at that time
fuming sulphuric acid in large quantities. The second process,
which is the one still in use, had quite independently been
worked out in Germany by Caro, Graebe, and Liebermann, and
patented in England practically simultaneously by these chemists
and by Perkin." 1

The demand for another coal-tar hydrocarbon, anthracene,
in large quantities and in a state of purity, necessitated further
pioneering work. Supplies of the crude material had to be
procured, the tar distillers had to be educated in the production
of raw anthracene, and factory methods of purification had to be
devised. It is unnecessary for me to remind you that all these
requirements were met by the science and skill of Perkin, then

1 The patents are: Caro, Graebe, and Liebermann, No. 1936, of 25th
June 1869, and W. H. Perkin, No. 1948, of 26th June 1869.

THE FOUNDING OF THE INDUSTRY 247

a young man just turned thirty years of age. The subsequent
development of the artificial alizarin industry is too well known
to need recital on this occasion. But there is one point in con-
nection with Perkin's work in this field which must not be
forgotten, and that is the great importance of the dichloranthra-
cene process in this country at the outset of the new branch of
the coal-tar colour industry. Perkin, in conversation with me,
has frequently emphasised this point, and I think it desirable on
the present occasion to place once again upon record this chapter
in the early history of the alizarin manufacture.

The two processes discovered by Perkin, and referred to in
the preceding extract, were the anthraquinone process and the
dichloranthracene process. In the first of these the anthracene
is oxidised to anthraquinone, the latter sulphonated by heating
with strong sulphuric acid to a high temperature, and the sodium
sulphonate converted into alizarin by alkaline fusion. The
sulphonation by this process yields a mixture of mono- and
di-sulphonic acids, and the final product is therefore a mixture
consisting of alizarin, anthrapurpurin, and some flavopurpurin.
This was the process first tried on the large scale by Perkin, as
well as by the German manufacturers. The second process,
which was patented here by Perkin a few months after the
patenting of the anthraquinone process, viz. in November 1869,
sets out from dichloranthracene, which is sulphonated by ordinary
strong sulphuric acid and the product submitted to alkaline fusion
as before. Now dichloranthracene sulphonates more readily than
anthraquinone, and as the product consists chiefly of a disulphonic
acid of anthraquinone, the " artificial alizarin " obtained by this
process consists mainly of anthrapurpurin, with some alizarin and
flavopurpurin. Alizarin, as you are aware, gives bluer shades of
colour than anthrapurpurin, so that although for certain purposes
where bright red was required the mixture obtained by Perkin's
second process possessed an advantage, for the production of the
bluer reds the anthraquinone product had the advantage. Perkin
met this difficulty to some extent by devising a method for
separating his " alizarin " into " blue shade " and " scarlet shade,"
but this method was not easy to carry out on the large scale,
and added to the cost of the final products.

For the first few years the Badische Company, which had
acquired the Caro-Graebe-Liebermann patent, worked by mutual
arrangement in combination with the Greenford Green factory ?

248 THE BRITISH COAL-TAR INDUSTRY

the latter having the monopoly of the English markets 1 The
Germans were using the anthraquinone process almost exclusively
this being, as you are aware, the method still in use. When
ordinary English oil of vitriol is used for sulphonating, a great
excess of acid is necessary and there is much loss owing to the
high temperature, so that the dichloranthracene process from this
point of view had the advantage. Moreover, when anthrapur-
purm was the mam object of manufacture it was found that the
product obtained by the dichloranthracene process gave much
purer shades than that obtained by the anthraquinone process."
It would have naturally occurred to Perkin in working out this
last process to try fuming sulphuric acid as a sulphonating agent,
and he did so with success; but this method, although giving
better results in the way of yield and uniformity of product, was
placed at a disadvantage here on account of the cost of the
turning acid. The advantages arising from this method of sul-
phonating are, I may remind you, an increased yield on account
of the lower temperature at which the acid does its work, and a
product which consists mainly of the monosulpho acid and
which therefore gives chiefly the true "alizarin" on alkaline
fusion. Now Germany was, at that time, the only country in
which the manufacture of fuming sulphuric acid was carried on
and this gave them a distinct advantage in working the anthra-
quinone process. Perkin has called attention more than once to
the / ta ' e , ot aia ! rs j m thj s country during the early life of the
artificial alizarin industry, and I cannot do better than quote his
own statements :

"On account of the expense and difficulty in getting Nord-
hausen sulphuric acid imported into this country-few vessels
liking it as a cargo we commenced working with ordinary
sulphuric acid. We usually employed four or five parts of this

f > r

' ahzarm," consistmg chiefly of anthrapurpurin. It may be pofnted out also
that, owing to some peculiarity m the internal administration of the German
Patent Laws at that time, the rights of Caro, Graebe, and Liebermann could
not be secured m certain States, and so other manufacturers took up "he
T n f mdUS T ry u and u entered into competition with the BadLche

t0 '-n, the anthraouinone process

THE FOUNDING OF THE INDUSTRY 249

to each part of anthraquinone and heated the mixture to
27O-28o C. . . . I find we employed this process principally
in our works until the middle of June 1870. We then began
to work on a larger scale than we had hitherto done with di-
chloranthracene, and carried both processes on for a time, but
finding the latter the more economical, partially on account of
the ease with which it yielded the sulpho acids with ordinary
sulphuric acid, we employed it almost exclusively after a time,
although frequently making colouring matter by the other
method.

" The large quantity of ordinary sulphuric acid which had to
be employed to convert anthraquinone into the sulpho acids, and
the high temperature which had to be used, causing a certain
amount of destruction to take place, evidently showed that it
was desirable to employ fuming sulphuric acid in this process.
In this country we found it costly, but as it was more readily
procurable in Germany, the manufacturers there used it. They
were afterwards supplied with a very strong fuming acid from
Bohemia, containing about 40 per cent, of sulphuric anhydride "
("The History of Alizarin," /. Soc. Arts.) 1879, PP- 2 4~ 2 5)- 1

The same statement was repeated in substantially identical
terms in 1896. Referring to the loss of anthraquinone when
ordinary sulphuric acid is used, he says :- " The means of over-
coming this difficulty was to use fuming sulphuric acid, with
which anthraquinone combined at a much lower temperature, but
the only acid of the kind then made was the old-fashioned Nord-
hausen acid. We imported a quantity of this, and, of course,
found it to work satisfactorily, but the difficulties and expense
connected with the carriage and transport of this substance on
account of its dangerous nature supplied as it then was in large
earthenware bottles made it unsuitable for use in this country.

"The artificial alizarin we first made was produced by the
anthraquinone process, the method still used for its manufacture,
but the difficulty in preparing the sulphonic acid in those early
days just referred to caused us to turn our attention to the second
process I had discovered, in which dichloranthracene was used. . . .

1 The use of Nordhausen acid for the anthraquinone process in Germany
began about 1871; the introduction of the stronger acid referred to by
Perkin in the above passage is generally attributed to Koch in 1873. Dr
Caro informs me that he has been unable to find the authority for this
statement.

250 THE BRITISH COAL-TAR INDUSTRY

Without this process the manufacture of artificial alizarin in this
country could not have been carried on with much success in the
early days of its manufacture " (Hofmann Memorial Lecture,
see p. 1 8 1, ante).

The " contact," or " catalytic," process for producing sulphuric
anhydride introduced about the same time in this country by
Messrs Chapman, Messel & Co., and in Germany by the late
C. Winkler, dates from 1875, so tnat Perkin's share in the
founding of this great industry does not consist only in his
having given us the practical methods for realising Graebe and
Liebermann's synthesis in the factory, but in having devised a
process which, so to speak, enabled the new industry to be nursed
through its infancy in this country and without which it would
probably not have survived that Continental competition which,
as Perkin has told us, first began to make itself seriously felt
about the end of I873. 1 By that time it was fully realised that
a complete revision of the plant at Greenford Green had become
necessary. It required enlarging and modifying in order to meet
the successful competition arising from the development of the
anthraquinone process in Germany, and a considerable expenditure
of capital would have been necessary to carry out this work. But
Perkin, whose ambition it had always been to be able to devote
himself to pure science, and whose personal requirements were
extremely modest, found that his manufacturing career had by
then provided him with sufficient means to enable him to retire,
and, rather than incur the responsibility of making a fresh start,
he took advantage of the opportunity for withdrawing altogether
from the industry. His career as a manufacturer terminated in
1874, the Greenford Green works having then been purchased
by Messrs Brooke, Simpson & Spiller, which firm, soon after-
wards, transferred them to Messrs Burt, Bolton & Haywood,
who shifted the manufacture from Greenford Green to Silvertown,
and ultimately from this firm the " British Alizarin Company "
was developed and is still at work. Perkin always wished it to
be known that he considered the Silvertown works as the lineal
descendant of the first coal-tar colour factory.

In this sketch of the founding of the coal-tar colour industry

I have necessarily limited myself to the history of the Greenford

Green factory. These works would now appear quite insignificant

in comparison with any of the great German establishments.

1 "History of Alizarin, "y. Soc. Arts, 1879 (see p. 57, ante}.

THE FOUNDING OF THE INDUSTRY 251

Although for the most part fallen into disuse, they were visited
with feelings of veneration by a large party of our foreign guests
during the Jubilee Meeting in 1906. Their erection in 1857
and their subsequent history had marked an epoch in the annals
of applied science, the importance of which was known full well
to those who had come to this country to render homage to their
founder. The whole output of dyes from these works during
the seventeen years that Perkin was connected with them was not
very great as measured by modern standards. Nevertheless, it
may fairly be said that no single factory established in this country
has ever given rise to such world-wide developments, both scientific
and industrial. When it fell to my lot to take part in the organi-
sation of the jubilee celebration in 1906, it occurred to me that
it would be of interest to place upon record the complete history
of the Greenford Green factory as a colour-making establish-
ment, and Sir William Perkin was good enough to prepare
for me the following list, which has not yet seen the light of
publication :

THE PRODUCTS MANUFACTURED AT GREENFORD GREEN,

1857-1873

Mauve. Large quantities manufactured.

Dahlia. Ethylmauveine, C 27 H 2 3(C 2 H 5 )N 4 . HC1. Made
about the same time as Hofmann's violet [1863]. The colour
was much admired, but being very expensive was not largely
used. (Jour. Chem. Soc., 1879, v l- xxx v. p. 399-)

Aniline Pink. First found in washings from mauve, after-
wards produced by oxidising mauve with lead peroxide. It is
parasafranine. Made about the same time as dahlia. (Jour. Chem.
Soc.) 1879, v l* xxx v. p. 407.) The researches were made many
years before publication.

Magenta. Prepared by mercuric nitrate under a patent in my
name ; a communication from abroad. It was first obtained in
crystals in this way. (Jour. Chem. Soc.^ 1862, vol. xv. pp. 238-
240.) The research was made some years before publication.
The process was dangerous and not carried on very long.

Amidoazonaphthalene. Used in a finely precipitated form as
an orange, red, or scarlet pigment for calico printing, but not
largely.

Britannia Violet (various shades). Made from magenta, the
bromine compound of turpentine, and methylated spirit, or,

252 THE BRITISH COAL-TAR INDUSTRY

better, purified wood spirit. At first thought to be a turpentine
derivative, but afterwards found to be methylated rosanilines.
Made in large quantities.

Perkins Green. This was an interesting compound made by
treating Britannia violet (blue shade) with acetyl chloride. The
latter was made in large quantities from phosphorus trichloride
and acetic acid. The phosphorus trichloride was made in cast-
iron retorts with iron condensers from phosphorus and dry chlorine.
The colouring matter was obtained in a crystalline condition, but
was not investigated as to its constitution. It was rather ex-
tensively used for calico printing when iodine green was too
expensive.

" Alizarin" Produced very largely, chiefly by dichloranthra-
cene process. It consisted of anthrapurpurin and alizarin, chiefly
of the former. These were also separated and sold as " scarlet
shade alizarin " and " blue shade," but we chiefly sold the mixture
known as " red shade."

Besides the above we made suitable mixtures of aniline salts,
oxidising agents, and copper compounds for the production of
aniline black. Also the colouring matters were made into " lakes "
by processes of our own for paperhangings and lithographic and
other printing inks in considerable quantities.

This list contains what may be regarded as Perkin's direct
contribution to the colour industry as a manufacturer. It may
not appear very imposing to us now, but we must read into it
all that it means in order to appreciate its full significance. Con-
sider the pioneering work in every direction that had to be done
in order to accomplish these results. Consider further that they
were achieved at the outset by a youth of about eighteen, and
brought to a successful termination in seventeen years by a young
man thirty-six years of age, and that during the whole of that
period, while the factory was actively at work, a continuous stream
of scientific research was kept going in his laboratory. Consider
also the stupendous consequences of the initiation of this industry,
and then you will realise the extent of our indebtedness to the
man whose labours in this field I have attempted to give you an
account of. I am aware that by many who regard manufacturing
industry from a narrowly patriotic point of view Perkin has been
censured for withdrawing so soon from the scene of his industrial
operations. The reply to this charge is obvious. He had made

THE FOUNDING OF THE INDUSTRY 253

a sufficient fortune for his modest requirements, and the seeds
which he had sown were developing rapidly in this country. At
that time (1874) German competition was only just beginning to
make itself felt. The industry was flourishing here, and with
respect to France it may be said that within a very short period
of the founding of the Greenford Green factory, and especially
from the time of the discovery of magenta, the industry was also
in a prosperous condition there. How thoroughly this branch of
manufacture had its head centre in England during the few years
following the opening of the Greenford works may be inferred
from the fact that such men as Maule and (especially) E. C.
Nicholson, both pupils of Hofmann, had entered the industry ;
that in Manchester the firm of Roberts, Dale & Co. had secured
the services of men like Caro and Martius, who later became
pioneers in the German colour-making industry. Or, if we turn
to the actual products, we find that, in addition to those emanat-
ing from the firm of Perkin & Sons, Simpson, Maule & Nichol-
son had secured the first really valuable process for making
magenta, viz. the arsenic acid process of Medlock ; that they
had also secured the beautiful process of Girard and De Laire
for phenylating magenta so as to convert it into blue and violet
colouring matters, and that Nicholson, by his discovery of the
method of sulphonation, had developed these into what were
for many years the most important of all the coal-tar colouring
matters. This firm had also introduced aniline yellow (aminoazo-
benzene), the precursor of the basic azo dyes, and phosphine
(chrysaniline), 1 the first member of the acrid ine series. They
were, moreover, the only manufacturers of the alkylated rosani-
lines under Hofmann's patent. Then the firm of Roberts, Dale
& Co. were making picric acid, and had, through Caro, given to
the industry the first induline obtained from aniline yellow and
aniline, as well as Manchester brown or Bismarck brown. This
firm had also, through Martius, given us the dinitronaphthol
known as Manchester yellow. Cyanine, or quinoline blue, the
first representative of a group of colouring matters which have
since become of great importance as special sensitisers for photo-

1 In the 1866 catalogue of this firm, already referred to, aniline yellow is
priced at 25., and phosphine at 35. per oz. The Nicholson blues were, at
that time, sold only in solution, the price ranging, according to the brand,
from 155. to 305. per gallon. Solid "Regina purple" is priced at 155.
per oz.

254 THE BRITISH COAL-TAR INDUSTRY

graphic purposes, was discovered the same year as mauve (1856)
by Greville Williams, who was for some time chemist at the
Perkins' factory, and who afterwards, with Messrs E. Thomas
and J. Dower, started the Star Chemical Works at Brentford.
This country may also claim to have been the pioneer, through
Crace-Calvert and Lowe, of Manchester, in the technical pro-
duction of highly purified phenol. 1 The first successful method
for printing on the fabric with aniline black was discovered and
patented in 1863 by John Lightfoot, of Accrington.

This was the state of affairs during Perkin's connection with
the industry, and, superadded to this manufacturing activity, was
the supremely important fact that, until 1865, the great master,
Hofmann, was among us, and that the laboratory at the Royal
College of Chemistry had become a centre of active research in
the chemistry of colouring matters which stimulated the industry
and supplied chemists for the factories. 2 Nor must it be for-
gotten that Peter Griess, the founder of diazo chemistry, was
working over here during the greater part of the same period.
It cannot be said that Perkin abandoned the ship in a sinking
condition ; on the contrary, she was steaming full speed ahead !
For any scuttling that may have afterwards occurred he can in no
way be held responsible.

The indebtedness of the colour-making industry to the
founder of the first coal-tar colour factory does not, however,
begin and end with his career as a manufacturer. The example
which he has set us as a man will for all time serve to point the
moral that all those qualities which make for success in industrial
pursuits scientific ability and knowledge, inexhaustible patience,
perseverance, resourcefulness, and energy may be conjoined
with the highest and best attributes of humanity. Such was the
personality of the man whose labours have added lustre to the
scientific and industrial history of our country, and whose loss
touches us the more deeply as representatives of that special

1 The state of the industry here and in France five years after its
inauguration at Greenford Green can be ascertained from Hofmann's
report on the chemical exhibits at the International (London) Exhibition
of 1862. It is not going too far to say that during its early years the
coal-tar colour industry was essentially English and French.

2 Hofmann left London in 1865. From that time until the creation of
the Chair of Organic Chemistry at Owens College, Manchester, in 1874, to
which Schorlemmer was appointed, there was no professorship in this
department of the science in this country.

THE FOUNDING OF THE INDUSTRY 255

industry which, in its present form, embodies the developed
results of his pioneering efforts.

ADDENDUM

As the introduction of fuming sulphuric acid played such an
important part in the early history of the artificial alizarin in-
dustry, I have thought it of interest to append the following
account kindly furnished by Hofrath Dr Caro. It may be
pointed out that the " contact " process for producing sulphuric
acid dates from I875, 1 and therefore subsequently to Perkin's
retirement, so that it was his successors who had the advantage
of this new branch of manufacture :

"Previously to the publication of Clemens Winkler, the
entire c Nordhausen Fuming Sulphuric Acid ' was manufactured
by John David Starck in Bohemia (in several works near Pilsen),
and was largely imported into England. It originally contained
about 20 per cent, of the free anhydride. This acid was
employed by Perkin in his first experimental manufacture in
1869 for sulphonating anthraquinone, and was afterwards in 1870
exchanged for ordinary sulphuric acid, 2 while we (the Badische
Company) commenced at this same period with the ordinary acid
and gradually went on increasing its strength by adding fuming acid
containing about 24 per cent, of free anhydride. I recollect that
in 1873 we used chiefly a mixture of two parts of the said fuming
acid with one part of the monohydrate. At the same time
we studied carefully the effect of the increased strength of the
sulphonating agent upon the separate production of the mono-
and disulpho-acids of anthraquinone, and I believe that at the
same time (1873) similar experiments were made by all German
alizarin makers, particularly by Gebrilder Gessert & Co.
at Elberfeld, and that in consequence of the superior results
obtained by the action of stronger acid at a correspondingly lower
temperature a demand was created for fuming sulphuric acid of
greater strengths than hitherto supplied. Thus John David

1 The patent of Messrs Chapman & Messel is dated i8th September
1875. Winkler's process was described in Dingier 's Polytechnisches Journal
for October 1875. Dr Messel gave a description of their process before
the Chemical Society in April 1876, but the paper was not published by the
Society.

2 See Perkin's statement (ante) quoted from his " History of Alizarin,"
1879.

256 THE BRITISH COAL-TAR INDUSTRY

Starck was led to manufacture the solid fuming sulphuric acid
containing about 45 per cent, of the free anhydride. This was,
I think, in 1873 or 1874. In 1875 we employed regularly the
fuming acid of 45-50 per cent, of anhydride. In 1877 we went
further in increasing the energy of the sulphonating action by the
employment of fuming acid of from 68 to 72 per cent, of free
anhydride, which we prepared by distilling the anhydride from
one portion of fuming acid into another portion of fuming acid,
containing 45-50 per cent, of free anhydride. We also distilled
the anhydride into the sulphonating mixture of anthraquinone
with fuming acid. Immediately after the publication of Winkler
in 1875 we commenced experimenting with his synthetical
process, and, after having many times changed our experimental
plant, we succeeded in manufacturing the fuming acid on a very
large scale from 1877. At about the same time other manu-
facturers started the manufacture of fuming acid by the
synthetical process."

XIX.: I 9 o8

LETTER FROM PROFESSOR H. CARO TO
PROFESSOR R. MELDOLA, MAY 1908

THE following letter from Hofrath Dr Heinrich Caro of Mannheim,
formerly chemical director of the Eadische Anilin- und Soda-Fabrik, is
inserted here on account of its historical interest. It bears the date
ityh May 1908, and relates to Professor Meldolas address to the
Society of Dyers and Colourists on " The Founding of the Coal-tar
Colour Industry" (ante, p. 234). Dr Caro had undertaken to write
an obituary notice of Sir William Perkin for the German Chemical
Society, but he died before the completion of the work. Professor
Meldolas obituary notice from the Chemical Society's Journal (ante,
p. 233) was therefore translated and adopted after some curtailment by
the German Society (" Berichte" 1911, vol. xliv.}. The letter is
given in Dr Caws own words without modification :

" MY DEAR PROFESSOR MELDOLA, Having now over and over
again perused your excellent historical account of c The Founding
of the Coal-tar Colour Industry,' which you have so kindly
sent to me, I beg to offer to you both the expression of my
sincere thanks and of my great admiration. Although the main
object of your Presidential Address to the Society of Dyers and
Colourists has been to erect an everlasting monument to the
memory of Sir William Henry Perkin's industrial pioneering work
in the field of the coal-tar dyes thus supplementing your prior
address to the Royal Society, 1 in which you so splendidly depicted
the life and the scientific research work of Perkin, you have given
to the world more than a mere personal and biographical account
of the great chemist and manufacturer. In those two joint pub-
lications you have embodied such a fulness of historical facts,

1 Obituary Notice: the Chemical Society's notice comprises both the
scientific and technical sides of Perkin's work.

257 17

258 THE BRITISH COAL-TAR INDUSTRY

partly as yet unknown, and commented upon by your own
authoritative remarks, that your Perkin Essays will for ever rank
amongst the most valuable contributions to the chemical history
of the last fifty years. You must have devoted an enormous
amount of thought, time, and labour in order to collect and
artistically to arrange the documentary evidence upon which you
have erected such a monumentum <ere perennis worthy of Sir
William Henry Perkin and his time.

" I now feel justly afraid to proceed with my own biographical
work on Perkin's life, which work is still in its infancy and which
I have been unwise to promise to the German Chemical Society.
You have already said everything that could be said on the
subject of Perkin's life-work, and it will be very difficult, if not
impossible, for me to discharge my task without following in
your wake and copying your writings. On the other hand, I
ought to be very thankful to you for having paved my way.

" You have kindly asked me whether I intend coming to the
International Congress of Applied Chemistry in London in 1909.
1 would certainly like to do so, and to visit once more dear old
England and my dear old English friends. If I were only
ten years younger ! But such unfortunately is not the case.
I dare not forget that the sun of my life is setting. With
my kindest regards, I remain, my dear Professor Meldola,
yours faithfully, DR H. CARO."

XX.: i 9 io

TINCTORIAL CHEMISTRY, ANCIENT
AND MODERN

BY PROFESSOR R. MELDOLA, F.R.S.

(Presidential Address, Society of Dyers and Colourists : Journal of the
Society of Dyers and Colourists^ 1910, p. 103)

THE FIFTEEN-YEAR PERIOD, 18701885, IN THE HISTORY
OF THE COAL-TAR COLOUR INDUSTRY, AND ITS LESSONS

IN dwelling upon the strengthening of the bonds between science
and industry as one of the most important functions of this and
kindred societies, I am prompted by the thought that the realisa-
tion of the importance the vital importance of this union has
not been fully grasped in this country even at the present time.
Our industry in the course of its history has furnished abundant
illustration of that principle which we as a nation have not
thoroughly assimilated the direct practical bearing of science,
even in its highest and most abstract form, upon technical and
manufacturing operations. For more than a quarter of a century
I have taken every opportunity of emphasising the object-lesson
conveyed by the history of that branch of chemical industry
which immediately concerns us here the manufacture of coal-tar
products inaugurated in 1856 by my illustrious predecessor in
this chair, whose services to that industry formed the subject of
my address two years ago. Perkin himself did more than any
worker of his time to inculcate that doctrine both by precept and
example. It is the spirit of propagandism which encourages me
to belabour this somewhat jaded hobby on such an occasion as
the present one, when it is my privilege to be able to appeal to
a wider public through the representatives of an art that is well
to the fore in the utilisation of the resources which science has

259

260 THE BRITISH COAL-TAR INDUSTRY

placed at its disposal and through the members of a Society
which may be congratulated on doing good service to that cause
which we all have at heart. So far, however, as I am concerned,
the preaching of the doctrine that the development of the coal-
tar colour industry is primarily the outcome of scientific research
is nothing more than the iteration of ancient history. It is
interesting to note in passing that it is considered necessary to
restate this fact from time to time with all the air of novelty. 1
But after all, if a principle is true, and if its truth is not generally
recognised, it may be desirable to freshen up the public mind
from time to time, if only for the purpose of reinforcing a lesson
which is in danger of being forgotten. From the opinion recently
credited to some Hungarian chemist (said to have been twenty
years in an English dye-house), in the organ of the Hungarian
Association of Chemical Industry, 2 in which both the facts and
their conclusions are distorted in a most remarkable way, it is
perfectly clear that there is still scope for reiteration. Fortun-
ately, it is possible for me to support the position which I have
always maintained by an appeal to that particularly critical period
in the history of the industry when I was connected with it, viz.
the period following the Franco-Prussian War of 1870. It was
soon after this great European disaster that the Continental
manufacturers began to get seriously to work, and some ten
years later we in this country and the French manufacturers ex-
perienced the first symptoms of serious competition from the
introduction of new products resulting from German discoveries.
Before 1870 and for a few years subsequently the list of synthetic
dyestuffs was a short one. Those made at Greenford Green
during Perkin's time (1857-1873) were given in a list published
in my last address to this Society (see p. 251, ante). The staple
products when I first entered the industry in 1870 were magenta
and the blues derived therefrom, the Hofmann violets, the
Britannia violets of Perkin, Bismarck brown, Manchester yellow,
indulines, alizarin, and methyl violet, the latter discovered by
Lauth in 1861 and manufactured in Poirrier's factory near Paris.
A few minor products, such as phosphine, aniline yellow, aldehyde
green, etc., were made by certain firms, but it is unnecessary to
swell the list. No good green for dyeing purposes was known,
and the so-called " iodine green " was too costly and fugitive to

1 See The Times' "Engineering Supplement," i;th November 1909.

2 Ibid.) gth February 1910.

TINCTORIAL CHEMISTRY, 1870-1885 261

be of much use. At the time of my second connection with the
coal-tar colour industry, which began in 1877, the ld state of
affairs was beginning to change at first slowly, but with increas-
ing velocity and at the time of my severance in 1885 the
change was progressing with such speed that I foresaw the
approaching decline of our supremacy in that industry, and did
my best on every possible occasion to direct public attention to
the existing state of affairs.

Now it happens that the period covered by my own personal
reminiscences say from 187010 1885 was the most active in
the discovery of new types of colouring matters in the whole
history of the industry. I do not mean to say that no new types
have been discovered since 1885, or that the actual numbers of
individual dyes put on the market since that date may not have
been greater than before that date. But it is the discovery of
new types or of the chemical constitution of old types which is
the scientific achievement which precedes and prompts the
industrial development and furnishes the manufacturer with the
means of producing new compounds of tinctorial value. With
the unravelling of chemical structure comes suggestions for new
methods of producing compounds of certain specific types, so that
the clue furnished by the determination of the constitution of
one compound may lead to innumerable compounds of the same
type being made available for tinctorial industry. It may be
instructive to recall a few of the more conspicuous cases which
occurred during the period under consideration. By way of
preliminary introduction it may be well to remind you of the
fact that the leading idea which furnished the key to the constitu-
tional formulae of the organic compounds being dealt with in the
colour industry, was the application of what is now called the
doctrine of valency to carbon compounds, and especially to
benzene and its derivatives, by Kekule" in 1865. That epoch-
making idea made its way very slowly in this country, while in
Germany it was being rapidly assimilated. I well remember in
the early years of my connection with the Chemical Society, that
the importance of the new benzene theory was realised by only
a very small number of our scientific chemists ; by the technical
chemists and manufacturers it was openly scoffed at, and those
who made use of the new ideas in their writings were jeered at
for " knocking about benzene rings." But if our manufacturers
failed to see any connection between an abstract theoretical con-

262 THE BRITISH COAL-TAR INDUSTRY

ception and its practical applications, this was not the case else-
where, and the examples which I propose to give will show some
of the results.

The oldest and most largely made dyestuff in the early days
of the industry was magenta or fuchsine, for the full history of
which I refer you to the books. This colouring matter had
been made the subject of much scientific study by many dis-
tinguished chemists, and its chemical composition and mode of
formation were well known. But its chemical constitution was
a mystery till the year 1878, when the problem was attacked by
chemists armed with a new mental weapon and, therefore, capable
of looking at the question from a new point of view. That
weapon was, of course, the Kekule theory, which had by that
time become part of the mental equipment of every truly scientific
chemist, and the chemists who paved the way for the solution of
this problem were Caro and Graebe, and the men who finally
solved it were Emil and Otto Fischer. It is only necessary to
state the bare facts here ; they are all recorded in history, but I
shall never forget the keen delight with which I first read those
memorable papers of 18781880, in which the Fischers proved
that parafuchsine and magenta were derivatives of the hydro-
carbon triphenylmethane and its homologue respectively. This
discovery settled a point which had engaged the attention of
chemists, from Hofmann downwards, for a period of about twenty
years. Turn now to the practical consequences of this purely
academic piece of work. The type had been revealed. Others
of the older dyestuffs, such as the methyl violet of Lauth, the
Hofmann violets, the phenylated blues, etc., were all seen to
belong to the same type. Furthermore, a well-known green
dyestufF, malachite green, discovered by O. Fischer in 1877 and
by Doebner (independently) in 1878 the first direct dyeing
green of real value and a few other greens introduced about the
same time or a little later, and all made by the same processes,
were proved to be derivatives of triphenylmethane. Then
followed the scientific development arising naturally from the
Fischers' demonstration, viz. the search, and the successful
search, for other methods of building up the triphenylmethane
type. Totally new methods were devised and new branches of
the industry sprang into existence. In addition to the aromatic
aldehyde method of Fischer, we had the so-called phosgene
colours, such as the Victoria blues, night blue, crystal violet,

TINCTORIAL CHEMISTRY, 1870-1885 263

etc., all of which appeared in 1883. In rapid succession there
appeared later dyes of the same type in which tetramcthyl-
diaminobenzhydrol or formaldehyde played the part of con-
densing agents. I have taken the trouble of compiling some
lists (from Schultz's tables), the results of which bring out this
chapter of applied chemistry in a very vivid way. Before the
Fischers' work, there were on the market, roughly speaking, some
twenty dyes of this class. I refer only to the basic dyes or their
suJphonic acids. Many of these older dyes were not definite
compounds at all, but indefinite mixtures or residues and by-
products. Now the manufacture of magenta began on the
small scale in France about 1859, so that the twenty dyes (of
which only some fifteen can be claimed as definite products) re-
present a period of activity of nineteen years. From 1878 to
1891, the latest date in Schultz's tables for a colouring mattter of
this type (Green's ed. of 1894), i.e. during a period of thirteen
years, twenty-four new colouring matters of this class were intro-
duced, everyone a definite compound and some of them competing
with and ultimately displacing some of the older dyes of the same
class, which, up to that period, had been the staple products upon
which some of our manufacturers here had absolutely depended
to keep their works going.

1 now turn to another large and important group of colouring
matters, the discovery of which belongs to the period with which
I am dealing. In 1871, Professor v. Baeyer published the first
of a series of papers on some new types of compounds which
he had obtained by the condensation of phenols with phthalic
anhydride and which he termed " phthalems." This, as in the
previous case, was at first a piece of purely scientific work.
Now, fortunately for that country, Germany had in one of her
new colour factories a chemist whose services we in this country
had lost a man whose name will be indelibly stamped upon the
history of the development of the coal-tar colour industry. I
refer to my old friend Dr Heinrich Caro, of Mannheim. It
was he who recognised the technological importance of Baeyer's
work, and turned this " academic " chemical reaction into a manu-
facturing process by his discovery that the substituted phthalems
were possessed of great tinctorial value. Thus appeared in 1874
the eosins, the bromo-derivatives of resorcin-phthale'm, and I have
a vivid recollection of the excitement with which I first experi-
mented with some of these beautiful new dyes when, somewhat

264 THE BRITISH COAL-TAR INDUSTRY

later, they first found their way to this country. The subsequent
history is substantially as before. The principle that substituted
phthalems were dyestuffs had been discovered ; further discovery
for some years turned upon methods for introducing various sub-
stituents into the phthale'lns, and the list was rapidly extended.
From this discovery of Baeyer's in 1871 there was thus developed
another branch of industry, creating a demand for raw materials
such as phthalic anhydride and resorcinol, which had never before
been made on a large scale. In the meantime, Baeyer and other
Continental chemists were slowly unravelling the mystery of the
chemical constitution of the phthalems, and after some years it
was shown that they were closely related in type to the triphenyl-
methane group. It may be of interest to add that the question
of the constitution of these compounds is still under investigation,
but this is a chapter of modern chemistry. The direct descen-
dants of these earlier substituted phthale'ins are the well-known
rhodamines, first introduced in 1887.

Another important group of colouring matters belonging to
the same period owes its origin to a discovery by Lauth in 1876,
viz. that certain diamines when oxidised in the presence of
sulphuretted hydrogen gave rise to the formation of violet
dyes. At first this also was a purely academic discovery ; Lauth's
violet never became an important addition to the list of avail-
able dyestuffs on account of its cost. But the same year the
principle was extended by Caro, with the result that methylene
blue was introduced. Here again I have a vivid recollection
of the sensation produced in this country by the introduction of
a new blue dyestuff. Up to that period all the known blues
were phenylated rosanilines. No basic blue soluble in water had
ever been available for tinctorial industry. The basic phenylated
rosanilines had, on account of their insolubility, to be used in
alcoholic solution, and the water-soluble blues were salts of
sulphonic acids. The chemical constitution of methylene blue
was attacked as a scientific problem by Bernthsen in 1883, and
successfully elucidated in a masterly series of researches which
bore the usual practical result. New and more advantageous
methods of making the colouring matter were discovered, and
the original methylene blue was soon followed by a number of
new dyestuffs belonging to the same type.

This same eventful period witnessed the introduction of
other great groups of colouring matters. It is unnecessary to

TINCTORIAL CHEMISTRY, 1870-1885 265

restate at length histories which are already upon record. I need
only mention naphthol yellow or acid yellow (1879), tne oxa "
zines (1879), tne indophenols (1881), the new series of azo
colours which began with chryso'fdine and naphthol orange
(1875-1876), fast red, the Ponceaux, Bordeaux, and Biebrich
scarlet (1878-1879), blue black (1882), Congo red, the first
of the direct cotton dyes and the first representative of that
enormous series of azo colours derived from tolidine, dianisidine,
etc. (1884-1885). Then we had the new series of quinoline
dyes beginning with flavaniline (1881), and the renewed interest
in the safranines and allied colouring matters arising from the
researches of Witt and Nietzki, and the consequent introduc-
tion of many new dyestuffs belonging to this type beginning
with phenosafranine (1878), the eurodines (1879), neutral violet
(1880), etc. Safranine, as you will remember, was first recog-
nised among the products of oxidation of aniline (crude) by
Perkin in 1861, and his own mauve, the first of the coal-tar
dyes, was in later times (1888) proved by Fischer and Hepp to
be a member of this same series. Within this same period also
falls the discovery of the first method of producing the sulphide
colours, which have since become of such great importance
and which began, in germ, with the old cachou de laval of
Croissant and Bretoniere in 1873. So also there remain to be
recorded the numerous and important developments in the ali-
zarin group, beginning with alizarin orange (1875), alizarin
blue (1878), alizarin blue S (1882), etc., gallem and ccerule'm
(1878), the first of the hydrazine colours, tartrazine (1884) ; and
sun yellow, the first of the stilbene dyes (1883). And last, and
by no means least, we have the first indigo synthesis by Baeyer
in 1880, and the second (Baeyer and Drewson) two years later,
and the settlement of the constitution of this all-important
colouring matter in 1888 by this same master worker.

CHEMICAL RESEARCH THE PRIME FACTOR IN THE DEVELOPMENT
OF THE COAL-TAR COLOUR INDUSTRY

I have narrated this chapter of industrial chemical history in
the barest outline, because the details can be filled in by reference
to existing literature. But I have spoken of nothing of which I
have not personal recollection, because at that period it was my
regular habit to keep myself acquainted, as far as was made

266 THE BRITISH COAL-TAR INDUSTRY

known through the ordinary channels of publication, with what
was going on in the colour industry outside our own works, and
specimens of the new colouring matters sooner or later found
their way into our laboratory. I claim therefore with some con-
fidence that this period of fifteen years was not only, as I have said,
a most eventful one, but it may even be permissible to go further
and to declare that it was the most critical period in the whole
history of the coal-tar colour industry. It was the period which
witnessed the introduction of nearly all the chemical types of
colouring matters on the market at the present time, and it was,
above all, the period which saw the stagnation and the commence-
ment of the decay of the British coal-tar colour industry. A
careful examination of the history of this period should therefore
furnish lessons of the utmost importance. What does this history
reveal ? In the first place, the broad fact that there was immense
activity in the way of discovery, and in the next place, that the centre
of this activity was not in this country. Consider all these new
types of colouring matters or every individual dye discovered
during the period, and it will be found that our national contribu-
tion to the industry was quite insignificant as compared with the
foreign and especially the German discoveries. The question of
the cause of the decline of the British industry resolves in reality
into the question of the cause of the Continental activity.

The answer to this last question has been staring us broadly
in the face for over thirty years. It is amazing that there
should have ever been any doubt about, or any other cause
suggested than the true cause, which is RESEARCH writ
large I The foreign manufacturers knew what it meant and
realised its importance, and they tapped the universities and
technical high schools and they added research departments
and research chemists to their factories, while our manufacturers
were taking no steps at all, or were calmly hugging themselves
into a state of false security, based on the belief that the old
order under which they had been prosperous was imperishable.
It is true that when the effects of the new discoveries began
to make themselves felt, one or two factories did add a research
chemist to the staff, but the number and the means of work
were totally inadequate. I happened to be one of them, and
so I speak with some practical knowledge of the conditions.
We were but a handful of light skirmishers against an army
of trained legionaries. What could three or four say half

TINCTORIAL CHEMISTRY, 1870-1885 267

a dozen at a liberal estimate research chemists, working under
every disadvantage, do against scores, increasing to hundreds,
of highly trained university chemists, equipped with all the
facilities for research, encouraged and paid to devote their whole
time to research, and backed up by technological skill of the
highest order ? The cause of the decline of our supremacy in
this colour industry is no mystery it is transparently and
painfully obvious. In the early stages of its decadence it had
little or nothing to do with faulty patent legislation or excise
restrictions with respect to alcohol. The decay of the British
industry set in from the time when the Continental factories
allied themselves with pure science and the British manufacturers
neglected such aid, or secured it to an absurdly inadequate
extent in view of the strength of the competing forces.

It has often been asserted that the British colour industry
suffered from the imperfection of our patent laws. I am quite
prepared to admit that there is some justification for this
contention ; our patent laws were faulty they are by no means
perfect now but that is a very different thing from the assertion
that the imperfection of the patent laws was the main cause
of our decadence. This I never did and never can admit.
The history of that fifteen-year period refutes it. I say, and
always have said, that it was primarily our neglect of science
which was responsible for our stagnation, in precisely the same
way as it may be said, per contra, that it was the appreciation
of science which was the cause of the progress of our competitors.
Had our factories been creative centres, as were the Continental
factories had discoveries of great industrial value been pouring
out of research laboratories here, I cannot but believe that the
pressure from within would have forced the hands of the
legislature, and would have brought about an amelioration of
the patent laws long ago. Instead of attributing the decline
of our colour industry to the imperfection of our patent laws,
the argument, as it seems to me, may fairly be inverted, and
it may be said that the imperfection of our patent laws was
largely due to our want of initiative in colour industry.

TINCTORIAL ART AS A SCIENCE

But enough has been said to enforce the lesson that the
development of that industry which chiefly concerns our Society

268 THE BRITISH COAL-TAR INDUSTRY

is the outcome of scientific research. And what is true for
the manufacture of those materials which the dyer and printer
have to depend upon is equally true for the development of
the processes for applying those materials. Tinctorial art is
as legitimately a subject for scientific research as is the discovery
of new colouring matters. The processes which go on in the
dye vat are still under investigation, and physical and chemical
interpretations of results which are of everyday experience to
the practical dyer are being sought by many scientific workers
pursuing many different lines of attack. This Society will do
well to keep in touch with this work, for the study of what may
be called the " inner mechanism " of dyeing is bound up with
some of the greatest theoretical questions of modern physical
chemistry. There is in this field another point of contact
between science and industry which it is our duty to keep ever
in view. Such purely abstract questions as the nature of the
" affinity " between fibre and colouring matter, or the relation-
ship between colour and chemical constitution, which are now
engaging the attention of some of the leading chemists of the
time, can no longer be ignored by the so-called " practical man."
The bearing of this work upon practical procedure, if not
immediately obvious, is as certain to make itself felt in the
future as were the speculations of Kekul6 and the researches of
the chemists of his time upon the development of the coal-tar
colour industry.

XXL: 1910

PATENT LAW IN RELATION TO THE
DYEING INDUSTRY

BY A. G. BLOXAM, F.I.C.

(Journal of the Society of Dyers and Co lour 1st s^ 1910, p. 119)

DURING the past thirty years patent law has been of great
importance to the dyeing industry, and conversely the dyeing
industry has been of great importance to patent law, and the
industry and the law have together achieved incidentally a much
greater result than their mutual benefit. The whole of organic
chemistry has been wondrously advanced by the desire of the
maker of dyestuffs on the one hand to obtain monopolies of new
colours, and on the other hand to avoid paying royalties under
existing patents.

The annexed curve (fig. 3), showing the number of patent
specifications relating to artificial dyestuffs of each year during
the period 1855-1907, is not without interest.

It was in 1856 that the artificial dyestuff industry had its
birth. No doubt picric acid, murexide, and one or two other
dyestuffs were made artificially prior to that year ; I have not
been able to find any patents for their manufacture earlier than
1856 ; their existence does not appear to have led to any
systematic study of how to make new colours, such as has arisen
since Perkin's Patent No. 1984, of 1856.

The curve is compiled from the official indexes ; the indexer
has included two specifications, prior to Perkin's, as relating to
artificial dyestuffs. One of these, however, deals with a modified
Prussian blue, and the other with a mixture of albumen and a
metallic powder.

269

270 THE BRITISH COAL-TAR INDUSTRY

It was not until Renard Freres patented fuchsine, in 1859
(No. 921/59), that the growth of this type of patent became
vigorous. That year produced a crop of ten, as is shown in the
curve relating to rosaniline dyestuffs (fig. 4). I should have
preferred to draw this curve for aniline dyestuffs generally, but
whereas it is pretty easy among the earlier patents to pick out
those which may properly be said to deal with aniline dyes, it

A/fZ7S7Z4Z

60 65 70 75 80 85
FIG. 3.

95 00 05

becomes almost impossible in later years to make this distinction,
because of the great differentiation that has occurred between the
numerous descendants of Perkin's patent. The official indexer
has classed Perkin's patent in the azine group, so that this patent
is not recorded in the rosaniline curve.

The rosaniline curve attained its maximum in 1863, and
then declined rapidly, touching zero in 1868 and again in 1872
and 1875. It will be seen that up to this latter year the artificial
dyestuff curve and the rosaniline curve are very similar, showing

PATENT LAW IN RELATION TO DYESTUFFS 271

that for the first twenty years little else was done than the ringing
of the changes on aniline and its homologues. The differences
between the rosaniline curve and the general curve up to this
point are largely due to the anthracene dyestuff curve (fig. 5),

1 55 60 65 70 75 80 85 90 95 00 05

FIG. 4.

which sprang into being with Liebermann and Graebe's Patent
No. 3850, of 1868, for the manufacture of artificial alizarin.

There were also a few specifications relating to azo dyestufFs
in this period, it having been discovered that by treating amines
with nitrites, dyestufFs could be obtained (fig. 6). It was not,

15
10

/fv

/ V

55 60 66 70 75 86 85 90 95 00

FIG. 5.

however, until Griess's Patent No. 3698, of 1877, that patenting
received the fresh blood which it seemed to require. It was in
this year also that Germany adopted her celebrated patent law,
and it rapidly became the custom to patent in this country all
the more important dyestufF inventions patented in Germany.

Turning to the curve of sulphurised dyestufFs (fig. 7), Caro's
Patent No. 3751, of 1877, for a dye of the methylene blue class

272

THE BRITISH COAL-TAR INDUSTRY

appears to have been the first, and until 1884 all the dyes thus
classified seem to have been of this type. In 1884 Vignon &
Co. patented the process of melting paraphenylenediamine with
a molecular proportion of sulphur and oxidising the product ;
several others of this type followed, but it was not until Vidal's
Patent No. 9443, of 1894, that sulphurised dyestuffs really made
a start. From 1898 to 1899 they jumped from fourteen to
forty-six, an increase which it would be hard to rival in any

50
45
40
35
30
25
20
15
10
5

1865 60 65

75 SO 85 90 95

FIG. 6.

r~o5

subject-matter unless it be the bicycle class ; since then, however,
they have steadily declined, falling to thirteen in 1907.

1880 was the year of Baeyer's first patent (No. 1 177, of 1880)
for making indigo. It was from orthonitrophenylpropiolic acid,
and it did not prove a commercial success. Ten years passed
before the Badische Anilin- und Soda-Fabrik patented (Nos. 8726
and 10,509, of 1890) the phenylglycine process, really due to
Heumann. Even then patenting did not become general until
1898 ; it attained its maximum in 1901, and is now on the
decline (fig. 8).

These curves, it must be said, only partially represent the
activity in the industry. As I have already mentioned, they are
limited to specifications which profess to produce the respective

PATENT LAW IN RELATION TO DYESTUFFS 273

dyestuffs. Intermediate products are not included unless they
are described in the same specification as the dyestuff. In the
case of indigo in particular this makes a considerable difference

45
40
35
30
25
20
15
10
5

1855 60 65

is r A

FIG. 7.

in the idea one obtains of the extent of the patenting from a view
of the curve ; a large part of the work expended on the subject
has been directed to the manufacture of substances destined to
be finally converted into the dyestuff.

15
10

^A/\

55 60 65 70 75
Fie

85 90 95

r. 8.

The azo dyestuff curve is also rather a poor representation
of the activity, although here it is more frequently the case that
intermediate products and dyestuffs are described in the same
specification. Probably the sulphurised dyestuff curve is most
free from this defect, and therefore the much greater number of

274 THE BRITISH COAL-TAR INDUSTRY

patents in this branch is not so remarkable as would appear at
first sight.

Prior to 1883 provisional specifications not followed by a
complete specification were published, and are included in the
curves ; subsequent to that date only complete specifications
have been published, so that in comparison the number of appli-
cations appears smaller.

The maximum of patenting coincides with the maximum of
sulphurised dyestuffs, and the heavy decline of the latter during
the past ten years has been accompanied by a serious decline in
the total number of patents ; however, there has been a distinct
recovery since 1903, due chiefly to the increased demand for lakes.

The last decade of the nineteenth century was certainly one
of marvellous synthetic activity ; probably we shall see the like
again, but in what direction it is not easy to prophesy. Indigo
having succumbed, there does not seem to be any natural dyestufF
worthy of sustained attack from the technical standpoint. Some
life is at present (1910) exhibited by dyestuffs of the anthracene
series, but otherwise the industry may be said to be resting.

It is a matter of some surprise that the manufacturers have
been so eager to patent their dyestuffs. Where successful secret
working is possible the monopoly may be much longer than that
afforded by a patent, and far less troublesome in many respects.

Fortunately for the industry and for science, the manu-
facturers have preferred to patent ; it is sincerely to be hoped
that they will continue to do so, for no thoughtful man can fail
to realise the immense benefit which must accrue from a system
by which inventors are given every encouragement to pour their
inventions into the lap of the public, notwithstanding that there
is much which the public do not want. Indeed, this must be
regarded as the reasonable basis for a patent law.

Abolitionists in respect of patent laws are practically extinct.
Switzerland has succumbed, now granting patents not merely for
embodied inventions, but for processes. Holland abandoned
her fifty-year-old law in 1869, but is now about to legislate again
in favour of patents.

It cannot be gainsaid that industry benefits enormously by
the publication of inventions ; the intended benefit, namely, that
the public may know how to exercise the invention at the expira-
tion of the term of the grant, is small compared with the stimulus
given to fresh invention, not merely by leading the reader's

PATENT LAW IN RELATION TO DYESTUFFS 275

mind into fresh fields of thought, but by the desire suggested
on the one hand to " go one better," and on the other hand to
evade the patent claim. This direct benefit to industry may
even be eclipsed by the indirect benefit procured through the
educational value of the publication. Patent specifications are
becoming our best technical journal, albeit one in which much
rubbish is printed.

It is the compulsory and immediate publication as a condition
of the patent grant which has led to the present highly developed
state of the artificial dyestuff trade and of organic chemistry.

It was largely due to the representations of Mr Levinstein
that the Board of Trade appointed a committee at the end of
1900, whose report gave rise to the Patent Act of 1902. This
provided a modification of the compulsory licensing clauses
(which did not prove satisfactory) and introduced a system of pre-
liminary examination, which came into force on ist January 1905.

Five years' experience of the working of this system has not
caused me to vary my opinion that a preliminary examination is
not advantageous either to the public or to the inventor. The
system involves a search among specifications to British patents
published during a period of fifty years prior to the date of the
patent application under examination.

A few years hence, when a considerable number of the patents
dated 1905 and onwards have come before the courts, we shall
be in a position to judge whether the preliminary examination
has had any effect in enabling the patentee to place more reliance
upon his patent. I am not hopeful that this will be the case.
So far six patents which have been subjected to preliminary ex-
amination have been before the courts, and of these only two
were upheld as valid.

As I have already stated, patents ought to be granted primarily
for the purpose of informing the public how new manufactures
are to be conducted. 1 think there is sometimes a slight con-
fusion of ideas as to the nature of the reward which is supposed
to be bestowed on the inventor by the patent grant. I take it
that the reward is a recompense to the inventor for disclosing the
manufacture ; it is one which must depend entirely on his own
exertions, since the sole profit which he can reap is in working
the invention himself or persuading others to work on a royalty.
The reward is not one for establishing a new industry or manu-
facture. The difference seems to me considerable ; in the one

276 THE BRITISH COAL-TAR INDUSTRY

case the contract between the public and the inventor is that he
shall have the sole right to endeavour to establish the manufacture
and to continue the manufacture if established. In the other case,
the contract would be that the inventor should have the sole
right to manufacture when the manufacture had been established.
Provisions as to immediate publication would be useless in the
latter case, and, indeed, injurious both for the public, as rerfdering
it less likely that the manufacture would be established, and to
the inventor, as telling all his competitors in what direction he
was endeavouring to obtain the patent reward. Publication
would not be necessary until after the establishment of the
manufacture, and then only for the purpose of defining the pro-
tection afforded by the patent.

The patent grant as a recompense for publication ensures
that there shall be no chance of the public losing the increased
convenience, comfort, and economy due to the ingenuity of the
inventor. At the same time it is inexpedient that the inventor
should be allowed to sit on his patent rights, and thus delay the
public enjoyment of the fruits of his invention for the whole, or
a considerable part, of the term of his patent.

Partly for the purpose of checkmating the dog-in-the-manger
patentee, many countries adopted what is known as compulsory
working, the patent becoming automatically void after a few
years if not worked in the country. This is a very severe
measure ; the number of patentees who need chastisement for
declining to work their patents is relatively very small ; the great
majority of patentees yearn to have their patents worked, and
spend much labour in endeavouring to get them worked. Re-
garded as a measure against the dog-in-the-manger, this system
has never found favour in our country.

On the other hand, the compulsion to grant licences on
reasonable terms when requested to do so appears free from
objection, and this mode of meeting the objection under con-
sideration has been steadily put forward ever since the beginning
of the last century. The difficulty of determining what should
be the conditions precedent to the compulsory licence seems to
have been the obstacle in the way of the adoption of the mode,
and it was not until the Act of 1883 that any provision found
its way into our law. The difficulty is not yet settled, however,
since the amending Acts of 1 902 and 1 907 have both varied the
original conditions

PATENT LAW IN RELATION TO DYESTUFFS 277

No system of compulsory licensing or compulsory working
exists in the United States. Personally I am disposed to think
that the system of compulsory licensing should be carried much
further than has been done in any country within my knowledge.
Why should it not be incumbent upon the patentee to grant
licences to all comers ? If he has spent time and capital in
setting up a manufacture of the invention before he is asked to
grant a licence, this fact must be taken into consideration in
settling the royalty. The patentee should have the opportunity
of being first in the field ; it would be only right that he should
not be compelled to grant a licence until his patent was of a
certain age. I do not see why the requirements of the public or
the public interest factors which it is always difficult to de-
termine should come into consideration.

Whatever system of compulsory licensing be ultimately
adopted, I am convinced that it will be found an adequate
substitute for compulsory working, not only in respect of pre-
venting the patent from becoming a true monopoly, but also in
respect of enforcing as far as possible the working of the patent
in the country of origin.

To some extent compulsory working is a corollary of pro-
tective tariffs. No amount of duty on an imported patented
article could serve to establish the manufacture of it if the
patentee had the power to veto the manufacture. Even in a
protectionist country, however, the policy of penalising non-
working by revocation of the patent is suicidal, so far as the
establishment of the manufacture is concerned. Those who
advocate this penalty are strangely illogical ; the patent was
granted, they say, to establish a new manufacture because no one
will embark capital in such an enterprise without some protection
from competition. If the manufacture is not established within
a certain period they would proceed to extinguish the sole in-
centive for establishing it.

At least the revocation should not occur until someone is
ready to work the invention. The position would be less absurd
if it were essential for the person applying for revocation to
show that he is ready to start the manufacture, and has a reason-
able prospect of an extensive trade.

To my mind, however, the greatest danger in the system of
revocation for not working lies in the fact that it is just the
patents which we require most that are most liable to revocation

278 THE BRITISH COAL-TAR INDUSTRY

on this ground. It is the patent which it is difficult to work in
this country that is most likely to establish a new industry ; the
revocation of the patent will only enhance the difficulty of
establishing the new industry. Hence inventors of the more
revolutionary inventions will refrain from patenting them until
such time as they think there is an opportunity of manufacture
being started. This will greatly retard the progress due to early
publication and the rivalry already alluded to.

After all, the inventor is granted the patent in consideration
of his having introduced^ that is, disclosed, the manufacture, not of
his having established it. And in practice this is how it happens,
almost universally. The inventor gets his reward from the capital-
ist before the manufacture is established ; it is the capitalist who
reaps a reward for having established the manufacture.

If patents are possessed by foreigners in order that they may
have a monopoly of importing into this country, the evil as I
will call it, though I am far from convinced that it matters to the
country is remediable by allowing Britishers or other foreigners
to obtain easily a licence for importing. If such patents are held
for the purpose of preventing manufacture in this country, a
compulsory licence will also serve as a cure.

DISCUSSION

Dr CAIN drew attention to the difficulty of keeping the manu-
facture of dyestuffs secret, as had been suggested by Mr Bloxam.
He mentioned the case of primuline. The manufacturer of
this dyestuff declined to take out a patent and decided to keep
the process a secret. Being the first of an entirely new class of
dyestuffs and, moreover, there being considerable difficulty in
ascertaining by analysis its chemical constitution, it was thought
that there would be no difficulty in keeping the matter quite
secret. Unfortunately, three weeks after the introduction on
the English market of this particular colour a similar colour
was put on the market by a German firm. He thought that in
the case of sulphurised dyestuffs there would be less difficulty
in keeping the matter secret. He was of opinion that the cost
of applying for compulsory licences for the working of patents
in this country was the reason of their not being applied for.
With reference to the so-called downfall of the chemical industry
in England, he mentioned the fact that Hofmann had often been

PATENT LAW IN RELATION TO DYESTUFFS 279

credited with the invention of coal-tar colouring matters, to
which he was not strictly entitled ; for example, Nicholson pre-
pared a number of products which were handed over to Hofmann.
Nicholson by phenylating rosaniline naturally suggested to a
chemist the methylating of the same product, the latter producing
Hofmann's violet.

Mr W. P. DREAPER defended the British system of chemical
training as compared with the Continental, and thought it was
more conducive to freedom of thought. In his opinion the
number of individual thinkers turned out in England was much
greater than was the case on the Continent. He thought that
compulsory search was to the advantage of the inventor, as he
was thereby enabled to go direct to the Patent Office and not
necessarily pass his invention through the hands of an agent.

Dr E. FEILMANN thought that the working of compulsory
licences might be settled in a businesslike manner, without
calling in the Law Officers of the Crown, the terms being
arrived at by the ordinary method of business bargaining, with-
out any interference on the part of paid officers.

Mr BLOXAM, in reply, expressed the opinion that the granting
of compulsory licences ought not to be anything like so costly as
was the case at present. He pointed out that the average dye-
stuff patent covered many hundreds of dyestuffs, and it was not
necessary to limit the specification to one particular dyestuff, as
was the case in the United States. He referred to the fact that
in the case of Levinstein, the Board of Trade made an order to
grant a licence, but no licence was actually granted.

XXIL: 1910

THE COAL-TAR COLOUR INDUSTRY OF

ENGLAND: CAUSES OF ITS PROGRESS

AND RETARDATION

BY I. SINGER

(Journal of the Society of Dyers and Colourists, 1910, pp. 124150)

THE question " Why did not the coal-tar industry obtain a sure
and permanent footing in the land of its birth, and why has it
reached such perfection and development in Germany ? " has
often been asked and variously answered, according to the
standpoint of the critic or the occasion which called forth the
reflection.

In this country the high excise duty on alcohol, the patent
laws, high wages, the free-trade policy, want of adequate second-
ary education, the supposed absence of research chemists, have
all been mentioned in turn as being concerned in obstructing the
development of the colour industry.

In Germany, however, entirely different views prevail. There
it is boldly asserted that inasmuch as the coal-tar industry is
essentially of a scientific character, it as naturally was bound to
become a German industry.

It was to be expected of their patriotism that Germans should
accept this explanation as satisfactory and all-sufficient, but it
caused no little surprise in other countries where the problem
has been discussed with as keen an interest, perhaps, as in
Germany itself, albeit it has not been viewed through German
spectacles.

This is probably the reason why the editors of the Vegvhzeti
JLapok the official organ of the Hungarian Association of
Chemical Industry have asked me to state the views entertained

280

CAUSES OF PROGRESS AND RETARDATION 281

in this country concerning this question. "We know," they
wrote, "that the Germans have written a great deal on this
subject, but we think it would interest our readers to have an
impartial statement of the opinions of the British consumers."

I responded to this appeal with an article which appeared in
the Christmas number of the Vegveszeti Lapok. I did not
attempt, however, to interpret the views of others, but gave my
own. In this article, originally intended for Hungarian readers
only, I tried to disprove certain allegations which, through per-
sistent reiteration rather than any inherent merits, have gained
currency abroad ; allegations which ascribed German supremacy
in this particular industry to the special aptitude of Germans for
scientific pursuits, and, inferentially, affirmed the want of it in
this country.

I pointed out not only the inadequacy, but the absurdity of
this explanation, and tried to show that the problem itself was
neither fairly nor correctly stated, inasmuch as many of the
assumed facts could be shown to be untrue or exaggerated.

I hoped the matter would end there as far as I was con-
cerned, but in this I was mistaken. An abstract of my article
appeared in the Chemical Trade Journal (i$th January), and thence
found its way into The Times (9th February) as an addendum to a
contributed article on " Research Chemists." Both these journals
were of opinion that my facts and arguments deserved some
attention. The Chemiker Zeitung of Coethen, however, is of
quite the opposite opinion, and is very wroth indeed with the
English Press for its indiscretion in taking notice of such abomin-
able heresies, since this compelled them to notice the article
themselves.

The most common idea is that England has lost the "coal-tar
colour industry through want of capable chemists. This opinion
finds expression in different forms. Even in this country com-
plaint is made that not sufficient attention is paid to chemical
research. The opinion seems to prevail that if more research
work were carried on, a larger share of the chemical industries
would be secured for this country.

In dissenting from this view, I do not wish to be understood
that I intend to disparage research work of any kind. Far from
it. The more there is of it the better, provided, of course, that
the means could be found to compensate those who would devote
themselves to the task.

282 THE BRITISH COAL-TAR INDUSTRY

In Germany they smile at the idea of England ever com-
peting successfully in the organic chemical industries, because,
they aver, it is a pursuit which can thrive only in the hands
of a scientifically gifted nation. They are quite sincere in be-
lieving that they possess special aptitudes for work which requires
deep thinking, careful and patient application, and regard the
conquest of this industry by Germans for Germany as a
crowning proof of " German thoroughness " and " German in-
tellectuality."

This belief was interpreted with sufficient clearness by Dr
Duisberg at the Perkin Jubilee banquet in the following words :
" No other industry requires so much uniformity of thought and
action, science and practice, as organic chemistry or organic-
chemical industry. . . . We Germans possess in a special degree
this quality of working and waiting at the same time, and of
taking pleasure in scientific results without technical success."

I could quote much more to the same effect, but this should
be sufficient. Nor would I have noticed this delicious specimen
of national self-appreciation were it not that, through constant
reiteration, people even in this country have become infected by
the belief that Germany has the command of this industry
because of her superior education, and that if this country only
produced more chemists, she would thereby secure a larger share
of the colour industry.

Now it is not necessary to question German genius or
German achievements in whatever field of activity, nor to put
forth rival claims on behalf of the British people before one
may dissent from such opinions.

The most superficial reflection must disclose the absurdity of
any suggestion that England has lost the coal-tar industry for
want of sufficient acumen, or that the industry owes its present
ramifications solely and entirely to German intelligence and
industry.

To guard against any possible misunderstanding, I hasten
to make clear my meaning. In the above sentence I do not
allude to the share of the work which chemists all over the
world, and of every nationality, had in making organic chemistry
what it is to-day ; nor do I intend to belittle the intelligence
and industry admitted and admired the world over which
Germans have displayed in its industrial application. They
have worked well ; their results are as brilliant as they are well

CAUSES OF PROGRESS AND RETARDATION 283

earned. But what I wish to insist upon is this, that all the
intellect and industry of a nation, however great, could not
possibly have made the coal-tar industry into what it is to-day
but for the inherent potentiality of the germ. As well ascribe
the widely diffused application of steam power, of electricity, of
railways, or the telephone to the " intelligence and industry " of
this or that nation.

In modern organic chemistry and organic syntheses a new

principle of wide application has been discovered, and the

enormous ramifications of this new industry must be ascribed to

this fact, and not to this or that nationality, even though it were

which it is not the monopoly of a particular race.

Great and rapid as has been the growth of the coal-tar
industry, it has not been more so than the spread of, say,
electricity, the telephone, the automobile, the typewriter, or any
number of industries that might be mentioned. All these have
grown rapidly to immense proportions because they supplied a
human want, because of their inherent potentialities, and not
because of the nationality of the people who were instrumental
in their creation.

Nor is it quite correct if leaving nationality out of the
question we credit the chemists with the creation of this
industry, any more than if we credited the electricians with the
creation of the electrical industries. At least it is as true to
say that these industries have called into being the chemists and
the electricians respectively, as that the latter have created the
former. The fact is that the chemists and the industry- have
created and stimulated each other, and the secret cause of their
success is the great demand for their products.

This insistence on a clear perception of the basic facts does
not in the least lessen the merits of our German confreres ; it
merely brings the different points involved into their true per-
spective. The Germans are known for thoroughness in every-
thing they do. They are as intent, as industrious, and as
scientific in their shipbuilding, their navigation, their spinning
and weaving, as they are in their colour making, and in time
may possibly eclipse their British cousins in all these industries.
But they have not done so yet. Would it not be absurd to
ascribe this superiority in particular industries to greater intelli-
gence in the British, or want of scientific attainment or thorough-
ness on the part of the Germans ?

284 THE BRITISH COAL-TAR INDUSTRY

For it is yet to be proved that more skill, science, or patience
is required to make, say, benzopurpurine, than to build, let us
say, a Leviathan (with its hundreds of details so carefully ad-
justed), a Jacquard loom, a combing machine, or that miracle of
mechanism a spinning mule.

It is begging the whole question to say that England has
not progressed in the coal-tar industry because she has not the
chemists necessary for its cultivation.

Germany did not have them fifty years ago. If she has them
to-day it is because the ever-expanding industry has called them
into being. And if England has not to-day as many chemists as
Germany trained in the organic chemical industries, it is because
there is no demand for them. Had they been wanted the supply
would have been forthcoming. The nation which produced men
like Boyle, Dalton, Davey, Graham, Priestley, Kelvin, Faraday,
Darwin, Tyndall, Huxley, Babbage, Arkwright, Stephenson,
Watts, Bessemer, Cartwright, Ramsay, Dewar, Perkin, Meldola,
and a host of others famous in science, art, and literature, might
conceivably have supplied men capable of being taught how to
sulphonate a phenol or diazotise an amine as in point of fact
she has done to the full extent of her requirements.

But the contention is too absurd and self-contradictory for
serious argument. For by a similar process of reasoning might
be proved German incompetency in respect of such arts or
industries in which they are excelled by other nations.

Another popular misconception is that England has lost the
colour industry, or that the industry has retrogressed. Phrases
implying one or the other are constantly met with both here and
abroad, without anyone ever deeming it necessary to prove such
assertions. It is simply stated and accepted as common know-
ledge. It is a common experience, however, that few things are
in greater need of careful investigation and confirmation than
the " facts " which " everybody " knows. Most of the assump-
tions connected with the problem under discussion belong to
this class, and should be looked into before acceptance. With
this object in view let us look at a few facts which are none the
less true because everybody does not seem to know them. One
of these generally forgotten is that the crude product, the
coal tar, has to undergo many transformations before it becomes
a colouring matter, and that at each successive stage of manu-
facture value is added to the product. Now a large part of these

CAUSES OF PROGRESS AND RETARDATION 285

preliminary and intermediary processes are performed in England
on a very extensive scale, and such products have been, and still
are, exported to Germany and other countries. That such
exports are not negligible quantities may be seen from the
following return for last year :

British Exports.

British Imports.

Raw and intermediary products .
Sundry coal-tar products (including
calcium carbide)
Indigo, synthetic .....
Colouring matters ....

Total ....

1,630,000
3,007,000

341,000

95,000
2,319,000

117,000
1,803,000

4,978,000

4,334,000

Excess of exports .

4,334,000

644,000

So that last year the United Kingdom produced ^644,000
worth of coal-tar products more than her own not inconsiderable
requirements.

This has been true all along the whole period of the coal-tar
industry. That is, expressed in money value, this country has
always produced more than the value of her own requirements,
though some products she imported whilst others she exported.

Let me state here another indisputable fact, though not
always remembered by those who talk about the " loss " of the
industry, or of its retrogression, and that is that at no time,
from the inception of the coal-tar industry to this day, was there
any retrogression. Quite the contrary ; every succeeding year
the total output, whether in coal-tar products generally or in
finished colouring matters, was greater than in the preceding
year, and is to-day greater than at any previous time.

There can be no question, therefore, as regards the progress
of the industry in this country, though that progress may possibly
not be comparable to that of Germany.

But even here we are in need of information before we can
say that the coal-tar industry as a whole, as distinct from that

286 THE BRITISH COAL-TAR INDUSTRY

of the finished dyestuff, has flourished more in Germany than in
this country.

I have no data to prove the contrary, yet I should not admit
this contention until some proof were forthcoming. I will state
my reasons.

In 1890 Gustav Schultz, in his Chemie des Stein-kohlen-
theers^ gave the following statistics of the quantities of tar
distilled for the purpose of colour making in the five principal
countries of Europe :

England . 400,000 tons Germany . . . 65,000 tons

France . . . 60,000

Belgium . . . 50,000 .

Holland . . . 15,000

Total . . 190,000 tons

Thus in 1890 England contributed more than twice as much
as all the other countries put together. As already mentioned,
this quantity of tar did not leave the country as such, but was
worked up into hydrocarbons, bases, acids, sulpho and nitro
compounds in fact, the manufacturing process was pushed on as
far as British industrial conditions permitted this to be done
profitably. True, none of these fall under the designation of
" colours," but they certainly form an integral and essential
part of the " coal tar " industry.

My point is this, that whilst the manufacture of these pro-
ducts has increased, their export has decreased. A private
communication to the writer by a member of a firm who are
among the largest makers of these products, explains this, as
follows :

" I am very sorry I cannot give you the figures you want
with reference to the amount of raw materials exported from
England to Germany in recent years, nor the amount of dyes
which are returned to this country made from such raw materials.
There are no available statistics for either of these figures.

"The export of intermediate and raw products to
Germany for aniline-dye manufacture has greatly decreased
during the last few years, owing to the fact that a larger pro-
portion of these raw materials is required for use in England.
The production of aniline dyestuffs in England has greatly
increased, while the production of raw materials has not. In
many instances the English works have nothing to spare of raw

CAUSES OF PROGRESS AND RETARDATION 287

materials, where they were formerly anxious to export. A
further reason for this diminution is to be found in the formation
of the large German combines, who have sought to make them-
selves entirely independent of the English supplies of raw
materials."

Two facts are here confronting us. Germany is less
dependent now for her raw material on England, and the
exports of such products from this country have decreased.
But .this does not mean that less of them is produced, for the
contrary is the fact. What becomes of them ? The answer
is partly supplied in the letter 1 have just quoted : "A larger
proportion of these materials is required for use in England,
since the production of aniline dyestuffs in England has greatly
increased."

I am aware that the British exports of finished dyestuffs is
insignificant as compared with those from Germany. But these
sums would not be a true measure of comparison. To these we
should have to add the values of domestic consumption, which in
England is, of course, incomparably larger than in Germany.

But do not let us lose sight of the main issue through these
comparisons. My object is not to contend that England's
share in the colour industry is satisfactory. I merely want to
show that the past and present agitation having for its object
the expansion of this industry is proceeding on wrong lines
and in wrong directions, and that because of the many false
assumptions.

What then are the actual facts ?

1. That this country has a large and flourishing and growing
coal-tar industry.

2. That it has also a colour industry, which has never yet
lost ground, but has steadily been advancing, and is to-day
greater than at any previous period.

3. That England not only more than supplies her own wants
in coal-tar products , but even in finished dyestuffs consumed
the major portion is locally made.

4. That some dyestuffs are produced in this country in
larger quantities than in Germany.

5. That whilst some of the colouring matters that have
been invented in England are neglected here in comparison with
Germany, others that have been invented abroad are successfully
manufactured here.

288 THE BRITISH COAL-TAR INDUSTRY

In view of such facts we can no longer allow ourselves to be
misled by such questions as " Why has England lost the colour
industry ? " or " Why has the colour industry migrated from
England to Germany ? " and so forth. Such leading questions
affirm far more than they ask and prejudice the whole problem.

It is not a fact that the colour industry has left the country,
or that it has lost ground. The truth is that certain parts
of the industry have been neglected, whilst others are
flourishing.

The matter for inquiry is therefore what part of the industry
is here neglected, and why ?

I will endeavour to give answers to these questions and show
that England has retained just so much of the coal-tar industry
as suited her own peculiar industrial conditions, and rejected
or neglected the rest ; that she resumed the manufacture of
such portions as, in the course of evolution, came within the
compass of these conditions ; that in this selection and rejection
the migration was not all in one direction ; and finally, that
intellectual superiority or competency on one side or the other
has nothing to do with this perfectly natural process of selection.

If we compare the industries which flourish in England with
those which have left, or are leaving the country, we shall have
no difficulty in arriving at the criteria by which to judge whether
a particular industry is congenial to local conditions or not.
For it is a great mistake to regard the colour industry as the
only one which has migrated from, or had been rejected, partially
or wholly, by England in the process of " selection and
adaptation."

Most prominent among the factors are undoubtedly the
economic conditions. In England wages and salaries are such
that an industry which does not lend itself readily to mechanical
manipulation and specialisation is, for that reason, more or less
unsuitable to the country. From this circumstance follow other
considerations, viz. that there must be a sufficient demand for
a particular article to warrant an economical outlay on buildings
and machinery.

What Mr C. W. Macara, the President of the Cotton
Spinners' Association, says of the industry of Lancashire is,
in substance, true of every industry in Great Britain.

He says : " The low cost of production is not due to low
wages and long hours of labour ; wages in Lancashire are higher

CAUSES OF PROGRESS AND RETARDATION 289

and hours shorter than in any cotton-manufacturing district in
the world. By wages, I mean what earnings will command
in necessaries and comforts. The low cost of production is
due to an economical first outlay on buildings and machinery ;
to highly efficient labour ; to efficient specialisation in the various
processes of the industry. ... In a word, it is due to enterprise,
organisation, and skill."

The keynote of all this is specialisation, which presupposes
production on a large scale. This must not be confounded with a
large trade, or a large aggregate turnover. For instance, on the
Continent might be found factories many times larger than
corresponding ones in England. But they will carry on a
multiplicity of processes and produce a miscellany of articles
which in England would constitute several distinct trades.

Not only do we have in England " combers," " spinners,"
and "weavers," as separate trades, but each of these branches
is again subdivided according to quality, some works confining
themselves to finer and others to coarser qualities of tops, yarns,
or cloth. Hence it is that though England is admittedly to the
fore in the textile industry, there are certain articles which she
cannot compete in that is, articles for which the demand is
too restricted.

And that also is the chief reason why certain branches only
of the coal-tar trade flourish in England whilst others are
neglected or have been entirely rejected. I say "rejected"
advisedly, as being nearer the truth than when it is alleged that
the industry has been " snatched " from England.

I will quote two facts in support of this contention. One
is to show that even if Germany were to relinquish entirely the
colour trade to-day, England would not make a bid for it, save
only for such portions as suited her peculiar conditions ; and the
other is to show that such portions she either has always possessed
or is acquiring in any case.

On the first point I cannot do better than quote Dr Duisberg,
although to do him justice he drew quite different conclusions
from the illustration.

He says : " One of the largest colour manufactories in
England had about ten years ago the licence for exploiting all
the English patents of two of the largest German colour works,
which at that time represented the value of many millions of
marks. It did not, however, in any way avail itself of this

290 THE BRITISH COAL-TAR INDUSTRY

advantage, although the English firm had no restrictions and
were no worse off than the German ones, as they merely had
to pay for this licence a very small portion of their net profits
to the patentees for the working of the respective patents." 1

In this case therefore it could no longer be a question of
inventive faculty, for the colours were invented, their processes
worked out, and at the disposal of the English manufacturer,
who yet did not avail himself of this advantage. On the other
hand, we have and this is my second illustration a British
Alizarin Company successfully manufacturing an article invented
in Germany ! Why ? The answer seems obvious enough.
Alizarin can be made in bulk, whereas " all the English patents
of two of the largest German colour works" comprised, on the
face of it, a miscellany of articles, representing "the value of
many millions of marks" in the aggregate^ but not sufficient
trade in any single article to make it into a specialised and
paying industry in England.

Phenol, benzol, naphthol, naphthylamine, their nitro and
sulpho compounds, etc., are such articles, and they are made
and have been made all along in England, not only in sufficient
quantity to supply her own wants, but also for export. Alizarin
is another such article, and, though invented in Germany, has
been successfully manufactured in England all these years.

But let us note here that the British Alizarin Company makes
only those brands for which there is a large consumption :
alizarin red, alizarin blue, and alizarin orange ; whereas
in Germany a much greater variety is manufactured. We may,
I think, take it for granted that the proportional margin of
profit on these three brands is much smaller than on the others
of lesser consumption. Yet the firm selected these three and
rejected the rest.

Thus restricting itself to what might be called the " bread-
and-butter " articles of the alizarins, the British Alizarin Company
has, for the last seven years, paid 10 per cent, dividends on a
capital of 138,000, and that in a market, be it remembered,
which is as open to the German makers as to itself. In view
of this should we be justified in assuming that the company does
not make the other brands because they are more difficult to
produce, or because it has not the chemists at its disposal ?
I believe the inference that there is not sufficient demand for
1 Speech at the Perkin Jubilee banquet.

CAUSES OF PROGRESS AND RETARDATION 291

these miscellaneous brands to make them into a paying industry
to be nearer the truth.

But and I wish you to note this point if a firm does
not think it worth while to undertake the production of such
articles as are already invented and at its disposal, either freely
or against the payment of a percentage on the net profits only,
why should such a firm, which exists for profit-making, keep
a staff of research chemists to make inventions which it would
not know what to do with when made ?

I imagine the answer that awaits my question. Germany
does so, and makes it pay. But Germany makes many other
industries pay which, under present conditions, could not be
profitable in England, and vice versa.

Again, I would remind you that I am not contending against
research work, nor that this or that industry is not worth
considering because it does not lend itself so readily to mechanical
exploitation. My only object is to point out the facts, so that
a remedy might be sought in the right direction. My point
is that it is neither the want of research nor shortage of capable
chemists that is the reason why certain branches of industry do
not flourish here so well as in other countries.

I will give an illustration from my own experience in support
of my contention. Let us take three colours that are produced
on the fibre : aniline black, para red, and naphthylamine
Bordeaux.

Appropriately enough, all three were invented in England.
Any difference there is in their production is in favour of
Bordeaux, which is certainly the easiest as well as the cheapest
to produce, whilst the black offers by far the greatest technical
difficulties. Yet, whilst of aniline black probably more is
produced in England than in the rest of Europe put together,
only comparatively little is being dyed of the red, and scarcely
any of the Bordeaux, though Germany is doing a considerable
trade in both the latter colours.

I repeat that were Germany to relinquish the synthetic colour
industry to-day, England would make a successful bid only for
those portions of it in which the consumption is sufficiently large
to warrant the laying down of special plant and on an extensive
scale ; and these branches she already possesses.

Alizarin and sulphide blacks the former invented in
Germany and the latter in France both became British in-

292 THE BRITISH COAL-TAR INDUSTRY

dustries as soon as the market for these articles was sufficient to
warrant a profitable outlay for their manufacture. Synthetic indigo
is another such article ripening towards eligibility for British
manufacture, and would be certain to become in time a British
industry, even without the recent patent legislation which impelled
the German patentees to start its manufacture in England.

On the other hand, the " two of the largest colour works "
mentioned < by Dr Duisberg as having unsuccessfully tried to
induce an English colour-maker to exploit their patents may, now
that they are established in this country, find out for themselves
that some articles can be more profitably produced in Germany
than in England, even by the Germans themselves.

We may agree therefore with Dr Duisberg in his contention
that it would not materially affect England's participation in the
coal-tar industry, even if she revised her patent laws. Not, how-
ever, because as he seems to contend the industry requires
talents which the nation is deficient in, but because the industry
comprises too many articles of but limited consumption to suit
British conditions.

Dr Duisberg is demonstrably wrong in his classification when
he assigns to England industries which are purely mechanical and
claims for Germany those which require " scientific thought and
application." His idea of Englishmen in the arts is as hewers of
coal and minders of machines. His words are :

" Whereas, therefore, the conditions in England for many in-
dustries, such as for the mining industry, for spinning and weav-
ing, not forgetting inorganic chemistry, are far more advantageous
than in Germany, the latter country has the natural privilege in
the organic chemical industry."

There is something patronising in this sentence especially
when, in addition to the hewing of coal and minding of spinning
and weaving machines, he suddenly remembers chemistry
inorganic chemistry. He came well-nigh forgetting it, though it
represents quite a respectable turnover. For the last year the
exports of what is classed under " Chemicals, Drugs, Dyes, and
Colours" amounted to over 16,000,000, the imports to
10,000,000, thus leaving a balance of exports over imports of
about six million pounds. To this modest sum, however, we
would have to add the home consumption, which probably may
be as great as that of the rest of Europe put together.

Somehow the eminent German doctor saw the " hands " only

CAUSES OF PROGRESS AND RETARDATION 293

in the British textile mills, and not the brains behind them. He
must have been so struck by the ease with which these machines
were worked that it quite escaped his notice that they had to be
invented, constructed, and improved until they became so
automatic that a child could superintend them. Yet those
machines can teach an eloquent lesson and illuminate for us the
very subject now under discussion. For it was necessity which
called those machines into being in a struggle for existence in the
strictest sense of the phrase, and the secret of their success is
specialisation and the division of labour, the two essential and
primary conditions of British industries.

In short, the question whether a particular industry is suitable
to English conditions does not depend on its character, whether
it is mechanical or chemical, organic or inorganic, requiring much
or little skill, but merely whether it is a bulk industry.

If you survey the field you will find that in each case where
an English firm takes up the manufacture of an article, it is the
one with the lowest margin of profit, and therefore the most
difficult to compete in. What is it that makes him choose thus ?
Not the smallness of the profit, nor the ease or difficulty of its
production, but the fact if I may use a slang expression that
there is " something to go at."

I have dealt with one large feature of the industry only, and
have given prominence to it because, though obtrusively present
in almost every important industry of the country, it is entirely
ignored in the discussion of this subject.

I do not pretend that it is the only reason why the colour
industry of this country is not greater than it is, but it certainly
is the chief one. Nor do I say that it is right it should be
so, that the country should reject every industry which cannot
be harnessed to a powerful engine. I only wanted to make
clear the fact that the tendency of British industries is towards
specialisation, and that, one by one, all those industries which
do not lend themselves to this process are being neglected or
eliminated.

I could name scores of industries which have left the
country, or are in process of leaving, for no other reason ; and
no amount of research work or inventions can prevent it.
You may ask, " Is there no remedy to arrest this ? " I believe
there is, but not merely by the erection of more universities
and laboratories.

294 THE BRITISH COAL-TAR INDUSTRY

You would have to devise means of organising these lesser
industries in such a way that they could be exploited profitably.

If a method could be found to do this and I do not think
it impossible or impracticable the chemists and inventors would
come forth without any special creative effort. We are all
worried about what to do with our boys. Create the field, and
the workers will soon crowd around you. But it is starting at
the wrong end to be clamouring for the chemists when you have
no use for them.

DISCUSSION

Dr CAIN wished to correct the statement of Professor
Duisberg, which had been quoted by Mr Singer, to the effect
that although a British firm of aniline-dye manufacturers had
had the opportunity of working in this country the patents of two
large German firms, it had not availed itself of that opportunity.
He thought there was no secret as to the identity of the parties
referred to, and he was able to contradict the statement from his
own personal knowledge, and to state that hundreds of tons of
dyestuffs had been manufactured in this country under those
patents by the firm mentioned.

Mr Singer's attitude with relation to the state of the British
aniline-dye industry was entirely opposed to that adopted by the
leading authorities, such as, for example, Professor Meldola,
Professor Green, and the late Sir William Perkin. These
authorities attributed the so-called decline in the industry to
the lack of employment of research chemists, and to the general
want of education on the part of the manufacturers. He (the
speaker) wished to associate himself strongly with these opinions.

Mr Singer's contentions were that there had been no decline
in the industry in this country, and if there had it was not due
to the cause referred to.

It was probably true, as Mr Singer had stated, that the
manufacture of dyestuffs here had gradually increased, and in
that sense the word " decline " was not, perhaps, strictly correct,
but for all practical purposes it represented the state of the
industry as compared with that of Germany. Mr Singer had
shown that a consideration of imports and exports did not
accurately represent the amounts of dyestuffs manufactured,
because it did not take into account the amount, according to
Mr Singer a very large one, which was manufactured for home

CAUSES OF PROGRESS AND RETARDATION 295

consumption. He thought, however, that no one would or
could deny that roughly about 95 per cent, of the dyes used
in England were of foreign manufacture.

That being so, the odd few per cent, could not represent
very much. Further, he did not agree with the lecturer's
suggestion that British manufacturers would not bother with
small manufactures, but would only take up the production of
dyes (or other materials) which could be made all the year round
with the minimum amount of expenditure on direction and
machinery. Mr Singer's illustration of the large quantities of
coal-tar products, in particular the cruder products, which were
produced in this country, was not a case where the British manu-
facturer had selected a manufacture especially suitable to the
economic conditions referred to. The larger quantity of these
products manufactured here, as compared with those furnished
by Germany, particularly in the past, was due to the fact that
we had always made much more illuminating gas in this country,
and, broadly speaking, Germany seemed to have jumped, in the
matter of illumination, from lamps to electric light.

There were dozens of dyestuffs, any one of which would
keep a large works going continually, but they had not been
made here, or, if they had, only to a small extent. What was
the real reason of this, and why had not a great dyestuff industry
arisen in this country as well as in Germany ? The cause was,
in his opinion, the lack of education both of the manufacturers
and of the people at large. The manufacturer had not in the
past really understood his business. He had not kept abreast
with scientific discovery, and did not realise the possibilities
of such discoveries as applied to his manufactures ; consequently
he did not see the enormous necessity of employing research
chemists. What was true of the individual manufacturer was
true also of the investing public. The average investor, he
thought, usually fought shy of investing his capital in businesses
concerned much with patents or the possibility of taking out
patents he suffered from the practical mind which often meant
one deficient in theoretical knowledge. He was incapable of
understanding the possibilities of applied chemistry, and con-
sequently capital flowed into other channels. This was not,
and had not been, the state of things in Germany. The higher
standard of education in Germany had had its effect on both manu-
facturers and investors, with the result that was seen to-day.

296 THE BRITISH COAL-TAR INDUSTRY

Mr SINGER, in reply, said that his contention was not that
England had as large a colour industry as she might or should
have, but that the reasons given for this shortcoming were wrong.
The prevalent idea seemed to be that England has lost the colour
industry for want of scientific equipment. He had disproved
this assumption by showing that neither has England lost the
industry, nor has the latter retrogressed.

The facts to which he tried to give prominence were : (i)
that in this country inventions were disregarded unless or until
they related to objects for which there was an ample market ;

(2) that failing such condition, an invention would be useless,
and hence an increase of the number of persons engaged in
the making of such inventions mere waste of time and money ;

(3) inventions actually made in this country were locally neglected,
whilst others, made abroad, were successfully exploited here.
From which he would draw the inference that it was not want
of education at all, but the tending towards specialisation, which
made mass production a necessary condition.

He would put it to the test, there and then, whether his
reasoning had any j ustification by submitting to his hearers three
proposals which everybody could answer for himself. The first
would be to form a company for the purpose of employing
research chemists with a view of exploiting their inventions.
Would anybody subscribe a single sovereign to such a venture
as a business speculation ?

His second proposal would be to offer them inventions
already made. Having assured themselves of the genuineness
and utility of the invention, would not almost their first question
be the probable consumption of the article, with a quick calcula-
tion whether it was at all worth bothering with ?

But if as his third he would put before them a well-
considered project, no matter of what kind, which showed a
reasonable prospect of a fair return of profits, could it be con-
ceived that such a project would fail for want of talent, scientific
or commercial ?

The subject for inquiry was therefore to find out why in-
dustries which could not be harnessed to powerful engines are
being neglected, or by what means such industries might be
organised and made into paying concerns consistent with the
economic and social conditions of the country. That is the
direction in which a solution of the problem under discussion

CAUSES OF PROGRESS AND RETARDATION 297

must be sought. Dr Cain had stated that he could mention
dozens of dyestuffs that would keep a large works going con-
tinually, but which had not been made here. He did not doubt
it. But would Dr Cain suggest he could not find the men here
to make them ? Surely not. Whatever may be the cause or
causes of the neglect of a particular industry, it cannot be the
want of talent, since that is always forthcoming in response to
the demand for it. He (the speaker) was at one with Dr Cain
in desiring more education and more research work ; but he
doubted whether these in themselves would advance the colour
industry. He was rather inclined to think it was the other way
about that the expansion of the colour and allied industries
would, by creating a greater demand for chemists, assist in their
creation.

XXIII. : 1914

THE ARTIFICIAL COLOUR INDUSTRY AND
ITS POSITION IN THIS COUNTRY

BY F. M. PERKIN, PH.D., F.I.C.

(Journal of the Society of Dyers and Colourists, loth November 1914, p. 339)

THE coal-tar industry was founded by my father, and in the
early stages of the work he received much encouragement from
Messrs Pullar, of Perth, particularly from the late Sir Robert
Pullar, the father of the present President of the Society. It is
doubtful whether, without that encouragement, he would have
commenced to manufacture the product he had discovered.

I will in the first place give a brief historical outline of the
commencement of the industry, then reasons why it ultimately
in a large measure passed to the Germans, and finally how it may
be possible, in part at any rate, to resuscitate the industry. The
views given are my own opinions, but I give them for what they
are worth.

In the Easter vacation of 1856 my father, who was at that
time just eighteen years of age, having been born on I2th March
1838, found that when aniline sulphate was acted upon by
potassium dichromate a black precipitate was obtained, and on
examination the substance was found to be "aniline purple or
mauve." This particular work was carried out in a rough
laboratory, which he had fitted up in his father's house, known
as " King David's Fort," at Shadwell, in East London.

As a matter of fact, the actual discovery of the dye was an
accident. The aim which my father had in view was the syn-
thesis of quinine. With our present knowledge we know that it
would not be possible to synthesise quinine simply by the oxida-
tion of aniline, but in those days, when organic chemistry was in

298

THE INDUSTRY IN THIS COUNTRY 299

its infancy, the assumption appeared quite probable. In 1856
it seemed quite legitimate to assume that a natural product might
be synthesised if the elements composing it could be brought
together in the right proportions.

Now, although the actual discovery of the dye was an
accident, it required a mind of particular aptitude to work up a
dirty black substance, to extract the dye, and afterwards to carry
out the laborious work which was necessary to prove that it was
a dye and could be used in place of dyes obtained from natural
products. I wish to lay stress on this, because the average
person the "man in the street" is apt to think that the dis-
covery of a substance is the main point. It is really not the
discovery of a new substance which is the chief thing, for
thousands of substances have been discovered which have been
put on one side as useless until the inventive mind came along
and opened out new branches of industry.

My father, having discovered this unprepossessing black
material, instead of throwing it away, experimented and found that
a brilliant colouring matter could be produced from it which had
the properties of a dye, and which resisted the action of light
remarkably well. Samples of silk and cotton were dyed with it
and sent to Messrs Pullar, of Perth, who, after examining them,
wrote on I2th June 1856 :

" If your discovery does not make the goods too expensive, it
is decidedly one of the most valuable that has come out for a long
time. This colour is one that is wanted in all classes of goods,
and could not be obtained fast on silks, and only at great expense
on cotton yarns .... and does not stand the tests that yours
does, and fades by exposure to air."

After further experiments, a patent was taken out (No. 1984,
1856), and it was decided to commence manufacturing. In June
1857 the building of the works was begun. In December of
the same year, the technical difficulties of manufacturing nitro-
benzene from benzene having been overcome, also the manu-
facture of aniline on a large scale from nitrobenzene, and finally
the oxidation and preparation of the dye, aniline purple, or
Tyrian purple as it was then called, was put on the market and
used for silk dyeing in the dyehouse of Mr Thos. Keith, of
Bethnal Green.

In introducing the new colour, an enormous amount of experi-
mental work had to be carried out. Mordants for use in cotton

300 THE BRITISH COAL-TAR INDUSTRY

printing had to be devised. Many experiments were necessary
before satisfactory results were obtained in dyeing wool and
silk with this new dye. It was, in fact, all pioneering work
from purifying the raw material and devising new plant, to finally
applying the new product.

In connection with the raw product benzol it is interesting
to note that it was manufactured only in small quantities in 1856,
and that the price was 55. per gallon for a comparatively crude
product, which had to be distilled before it could be used. The
coal tar itself was a drug on the market, and a great nuisance to
the gas manufacturer. With the advent of the aniline dyes,
and the consequent call for more and more of the products
contained in the tar, the conditions changed and by degrees tar-
distilling plants were erected, and became a source of profit to
the gas manufacturer.

The introduction of a new colour from a novel source
naturally attracted a great deal of attention, and as a consequence
many workers came into the field and a large amount of research
work was carried out with aniline and allied products, and the
number of synthetic dyes gradually increased. The second
aniline dye, magenta or fuchsine, was discovered in France by
Verguin, in 1859, who produced it by heating commercial aniline
with tin tetrachloride. In these early days quite a number of
British patents were taken out, although of course a great deal
of work was being carried on on the Continent. It must also not
be forgotten that a large amount of pioneering work was instituted
under the direction of the German chemist, Professor Hofmann,
at the Royal College of Chemistry, London. In fact, the in-
fluence of Hofmann was of enormous value, as he imbued his
students with a love of research, and taught them the importance
of thoroughness in their work. The Germans, recognising
Hofmann's great gifts, ultimately induced him to return to his
native land as a Professor at Berlin University.

In the early days of the aniline-dye industry, probably
owing mainly to the influence of Hofmann, there were many
German chemists in English works, a number of whom returned
to Germany and have most materially helped the German colour
industry.

My father's works at Greenford Green in Middlesex were
the first coal-tar colour works, but quite a number of other works
sprang up within a few years. Some of these no longer exist,

THE INDUSTRY IN THIS COUNTRY 301

but others are still with us and are of considerable size, employ-
ing a large number of hands.

A short time after the Greenford Works had been founded,
Messrs Simpson, Maule & Nicholson commenced to manu-
facture dyes, Edward Chambers Nicholson, one of the partners
and a student of Hofmann's, being a chemist of high attainments.
Simpson, Maule & Nicholson were originally manufacturers
of fine chemicals. When mauve was produced, they took up
the manufacture of nitrobenzene and then aniline, and gradually
developed into manufacturers of dyes, being the first, 1 believe,
to manufacture rosaniline in this country, and producing it in a
high state of purity.

Messrs Roberts, Dale & Co. began working before 1860.
Levinstein's commenced in a small way in 1864. Read Holliday
& Sons, Williams Bros., and Dan Dawson all commenced about
1865. From the first all these firms employed highly trained
chemists who, by their research work, did much to place the
industry on a strong basis. Many of the chemists, however,
were Germans who, as already mentioned, ultimately returned to
the land of their birth and, for reasons which will be mentioned
later, it was not possible to replace them by men of equal calibre.
The names of a few of these German chemists, who did so much
valuable work in England, may be mentioned : Dr Caro, who
ultimately became chief chemist to the Badische Anilin- und Soda-
Fabrik ; Dr Martius, who was later appointed chief chemist to
the Berlin Actiengesellschaft ; Peter Griess, the discoverer of the
diazo reaction (chemist to Allsopp's Brewery at Burton-on-
Trent) ; and Dr Otto N. Witt, who became Professor of
Chemistry at the Charlottenburg Technische Hochschule.

Up to 1875 * ne British industry was in a flourishing con-
dition, and fairly held its own against foreign competition ; and
a very large number of important patents were taken out in
this country. For example, Dr David Price, in 1859, patented
violine, purpurine, and roseine, which he obtained by oxidation
of aniline with lead peroxide. Medlock took out a patent in
1860 for magenta. In the same year, Greville Williams dis-
covered quinoline blue, afterwards known as cyanin. Patents
for violets were taken out in 1860 by Dale and Caro, and by
Smith and Coleman. In 1862 Perkin patented another series
of violets, and in 1863 Hofmann discovered a violet known as
Hofmann's violet, which was manufactured by Simpson, Maule

302 THE BRITISH COAL-TAR INDUSTRY

& Nicholson. Aniline black, probably the fastest of all blacks,
was discovered by Lightfoot in 1 863. It is unnecessary to further
enumerate.

A very great stride in organic synthesis was made in 1867 by
the German chemists, Graebe and Liebermann, who showed that
the vegetable dye, alizarin, could be prepared by fusing dibromo-
anthraquinone with caustic potash. They patented this process,
but it was far too expensive to be of commercial importance.

My father, when with Hofmann, having had special experience
of anthracene, and having kept considerable quantities from the
time when he was a student, was naturally much interested that
anthraquinone, which is obtained from anthracene, could be
converted into alizarin. He therefore studied the matter
further, and found that alizarin could be produced by sul-
phonating anthraquinone with fuming sulphuric acid and then
fusing with caustic soda. He also devised another method which
consisted in chlorinating anthracene and then treating with
sulphuric acid and afterwards with caustic soda. On treating the
melt obtained by one or other of these methods with acid, a
yellow precipitate was obtained, which dyed madder mordants
with the greatest ease.

All the alizarin used had, up to this time (1869), been pro-
duced from the root of the madder plant. This then was the
first synthesis of a natural or vegetable colouring matter.

At the same time that experiments were being carried out
in England, the German chemists, Caro, Graebe, and Liebermann,
were also investigating the subject, and discovered the sulphona-
tion process about the same time as Perkin. Although the
patents were filed within a day of each other, artificial or synthetic
alizarin was first manufactured in this country, and until 1874
the Germans sent very little into the United Kingdom.

In 1868 the amount of madder root produced was estimated
at 70,000 tons a year, but in a few years the artificial product
almost completely replaced the natural colour, and madder
ceased to be grown. The total output of alizarin from the
madder root was about 750 tons in 1868, but in 1912 the out-
put of the synthetic product had risen to about 2000 tons, four-
fifths of which was manufactured in Germany.

The development of this branch of the coal-tar colour
industry was thus described by my father in his Hofmann
Memorial Lecture in 1896 :

THE INDUSTRY IN THIS COUNTRY

303

"Before the end of the year 1869 we had produced i ton
of this colouring matter in the form of paste ; in 1870, 40 tons ;
in 1871, 220 tons; and so on in increasing quantities year by
year. As we had been successful in producing artificial alizarin,
others did not run much risk in following our lead ; yet up to
the end of 1870 the Greenford Green works were the only ones
producing artificial alizarin. German manufacturers then began
to make it, first in small and then in increasing quantities, but
until the end of 1873 there was scarcely any competition with
our colouring matter in this country."

He then went on to say and the remarks were not only
directed to his own work but to the work of other firms, notably
Simpson, Maule & Nicholson, who for some years were the
largest coal-tar colour producers in the world :

" From the foregoing it is seen that, as in the case of the
aniline colours, all the pioneering work connected with the
foundation and establishment of this branch of the coal-tar
colour industry was also done in this country.

" For the due development of this industry, it was necessary
not only to attend to technical processes, but also to carry on
scientific research in connection with it."

The neglect of scientific research during the next decade was the
reason why the coal-tar colour trade ^ established as it was in this
country^ gradually got forced out by German competition.

In 1874 the Greenford Works were sold to Messrs Brooke,
Simpson & Spiller, the manufacture of alizarin being taken
over at a later date by the British Alizarin Company.

I have seen it in the Press, and have also heard it in con-
versation, that it was not a very patriotic step to dispose of a
successful works at the early age of thirty-six. The reasons for
doing so were practically these. My father and his brother had
had a very difficult fight to establish the works, and had at last
reaped some benefit from their struggle. The use of aniline
and alizarin dyes was increasing by leaps and bounds, and
their agents all over the country were urging them to increase
their output largely. This practically meant doubling the size
of the works ; and this again meant that they would have to
sink most of the capital which they had made, in bricks, mortar,
and machinery. Although my father preferred a quiet life in
which to devote himself to research work, the increasing of the
works would probably not have been an insuperable difficulty or

3 o 4 THE BRITISH COAL-TAR INDUSTRY

prevented him from carrying on the business ; but the necessity
of having more trained research chemists, if the works were to
be carried on satisfactorily, became increasingly apparent. It
was not possible for one brain, however energetic and fertile, to
carry out all the necessary research required in a large works.
Research chemists, however, could not be obtained. Our
universities did not train them. True, Germans could be had
at moderate salaries ; but German research chemists, after they
had obtained a thorough knowledge of the processes, had a
tendency to go back to their own country, where they were
received with open arms and offered high salaries by the German
companies.

In an industry such as that of the aniline dyes, continual
change is necessary. Consequently, a number of highly trained
research chemists must be employed, and it is the works which
can turn out the largest number of new colours, and at the same
time improve the methods of manufacture and the quality of the
older ones, which will obtain the market.

This is what the Germans have done. It is not correct to
say except to a limited extent that they have stolen the
artificial colour industry from us. There certainly has been a
lot of piracy. In the early days of the industry, German patent
laws were, to say the least of it, chaotic, each State either having
its own laws or its own ideas as to the administration of the
patent laws. Therefore, for all practical purposes, no patent law
existed. It followed, consequently, that the Germans had the
brains of the world at their disposal and they had to pay no fees
for their use. The moment a patent was published it was seized
upon by the German firms. If a process was worked secretly,
the Germans, either by research work or by other means, dis-
covered it and appropriated it. The products manufactured by
them were sent into this country ; it was vain to prosecute their
agents, because when the Germans found this was being done
they supplied the goods direct to the consumers. They sent
their travellers, many of them skilled chemists, all over the world.
They were therefore able to show how the dyes were best
employed. The British manufacturers were, as a rule, content
with issuing circulars to their customers, warning them not to
use inferior foreign goods. As a matter of fact, the goods, as a
rule, were not inferior to the British, and were often cheaper.
It is, however, an undoubted fact that the German colour works,

THE INDUSTRY IN THIS COUNTRY 305

when they were first founded, stole the work of English brains.
The British Government protected their processes by allowing
them to take out patents in this country which they were not
required to work. On the other hand, German patents were
refused to the British inventors. This was the case with the
alizarin patents ; they were granted to Germans in England, but
refused to Englishmen in Germany.

I do not think that the German competition with alizarin
was very serious until after 1874, because, up to that time, it
could be manufactured and sold at a good profit at a price which
did not admit of much German undercutting. Shortly afterwards
the price of the alizarin paste in this country was raised, and
this gave the Germans their chance, which they seized with
characteristic energy and undersold the English manufacturers.
The English policy should, of course, have been in the opposite
direction, to keep the price low, particularly as the Germans were
getting in a position to supply the whole demand, if they could
only obtain the trade. As a matter of fact, by combining together,
the German manufacturers for a time practically killed the
British alizarin industry, and had it not been for the Turkey
Red Dyers' Association, who combined to manufacture alizarin,
the trade would probably have entirely left the country. At any
rate, the Germans have made very great profits, and employed
these in the first case to write off their capital expenditure, and
secondly to reconstruct and equip their works with magnificent
laboratories, staffed with skilled research chemists. The patent
laws, until the Bill of 1907 was passed, allowed foreign nations
to patent any process in this country simply to prevent us manu-
facturing, while we, if we patented abroad, must manufacture the
product in the particular country in which the patent was taken
out within a reasonable period, or else grant a licence.

In 1907 the Patent Laws Amendment Act was passed, in
which it was made compulsory for a foreign patentee either to
work his patent in this country, or else to be compelled to grant
a licence. Unfortunately, many loopholes for evading this Act
have been discovered, and it has not been so successful as was
anticipated.

With our own patent laws against us, the Germans made the
most of it. But the German spy system, of which we have seen
so much recently, was also against us. In many cases, however,
our want of business method and always our disdain of research

306 THE BRITISH COAL-TAR INDUSTRY

work were against us. After a process was once started it was,
and even to-day is, largely worked by rule of thumb. I grant
you there is a stirring amongst the dry bones, yes, a great stirring,
but if we are going to take our place in the manufacture of
aniline dyes and fine chemicals, the stirring will require to be
very much more vigorous, and unless, after being stirred, the
bones are going to be jointed together, little ultimate good will
result.

I have pointed out how the Germans, owing to our patent
laws, were able to make use of our brains, and one cannot help
thinking how fertile those brains were with new ideas, and with
initiative to carry out the ideas from the experimental to the
manufacturing stage. It must be remembered, however, that the
number of these pioneers was not very great, and it is small
wonder if, when they found their ideas being exploited by others,
they were inclined to lose interest, and retire from the fray.
Whether or not this was the case I am unable to say, but in this
particular line of industry we seemed to lose our pioneering
interest. The existing works in some cases, at any rate, began
to live on their past reputation and seemed to make very little
effort to compete with their German rivals. On the business
side they did not take sufficient trouble to keep their customers
or to open out new markets. The dyer was told, if not in words,
at any rate by action or want of action, " These colours have
always been admired and have been manufactured by us for years,
we don't see any reason for altering the shades or the methods
of dyeing."

In the meantime, however, the Germans were flooding the
markets with new dyes and new shades and sending round their
travellers by the score. These travellers were not simply sales-
men, but in many cases trained chemists, who were prepared to
go into the dyehouse and show the dyer how to apply the dyes.

The question of capital also had a great deal to do with the
advancement of the artificial colour industry abroad. In this
country all the firms were privately owned, being more or less
family concerns. To-day this is in the main still the case. In
Germany it was and is otherwise. They are big commercial
concerns, supported by outside capital and also by the banks.
Furthermore, a large slice of the profits has always been put by
for developing the works, for new machinery, and for research
work. We in this country have been too prone to take too

THE INDUSTRY IN THIS COUNTRY 307

much out of the business, instead of building up large reserves.
One might say, why then was not outside capital brought in to
increase the size and output of the works ? The reason probably
was this that capital found a more remunerative opening in
shipping industries and the building of docks, the opening up
of coal mines, in the heavy chemical trade, and in engineering
concerns, etc. Also a large amount of capital was invested
abroad to finance British or foreign undertakings from which
good profits could be obtained.

One of the chief causes of our not being able to hold the
artificial colour industry which had been founded in this country,
and the real cause of the German pre-eminence, and for which
they deserve every honour, was the lack of industrial research.
One of the reasons why so many of the students of Hofmann
rose to such eminence was the love of research with which he
imbued them. To-day our manufacturers are awakening to the
need and value of research, but for many years, although a
chemist was attached to most of the works, he had in the main
simply routine work to pursue, which either gave him no time
or incapacitated him for research, and this is still largely the case.
Small wonder is it that our manufacturers were unable to compete
with the Germans. In the German works, shortly after their
foundation, magnificent laboratories with all the latest scientific
apparatus were erected. Libraries stocked with the latest literature
were installed everything was there which might be required for
the investigations in hand.

Having made these preparations, chemists were employed
who had had a thorough training. Before they could take their
degrees it was compulsory that they should carry out an original
investigation along some line of research. The engineers employed
were also highly trained men with a good chemical knowledge,
many of them having received a university education. In the
works the chemist and engineer worked hand in hand. Thus,
when the chemist had discovered some new material or process
in the laboratory, it was further worked out in collaboration with
the engineer-chemist. The product first produced in the laboratory
was next made on a semi-commercial scale, and if this proved
successful, the commercial plant was erected and the material
manufactured in bulk.

As the output of the works increased, so the number of
chemists taken into the works increased until, as is well known,

3 o8 THE BRITISH COAL-TAR INDUSTRY

some works, such as the Badische, and Meister, Lucius & Brun-
ing, employ over two hundred research chemists. The fact is that
almost the whole of the technical staff are more highly trained than
is usually the case here. There is also in Germany a much closer
relationship between the professors of chemistry in the universities
and polytechnic institutes and the manufacturers. This is good
for the professors and good for the manufacturers, as it reacts
upon the training of the student.

How could British manufacturers who, if they did not scorn
research did not recognise its value, compete under these con-
ditions ? During the last decade British colour makers have
been holding their own in certain lines, and even improving their
position, owing to the fact that they have been increasing their
technical staff. But they have been, and are, severely handi-
capped by the enormous German advances and by the great
variety of products the Germans have been able to supply to
the consumers. The agent of a German firm can go to the dyer
and offer him all the shades he requires, the British manufacturer
can only supply a few : consequently, the German gets the order
it saves so much trouble.

There are other reasons which are more closely related to the
German business methods, but I will not go into these, as I do
not wish to enter into controversial matters.

I am not fond of the expression, " War on German Trade."
Is it not better to say, " Opportunity for British Trade and the
Capture of New Markets " ? The Germans thoroughly deserve
the pre-eminent position which they have attained in the artificial
colour industry. It is in the main due to painstaking research,
backed by thorough business organisation. Some of their
business methods, it is true, are such that we should not care
to see them copied here, but the main reason has been the lack
of research, and of making opportunities, instead of waiting for
them to come.

Did not the Germans deserve to capture the indigo industry ?
The research on this subject was carried out on a truly colossal
scale. Many chemists were engaged for a period of over twenty
years upon research work in order to produce this product syn-
thetically on a commercial scale at a price which would compete
with, and even undersell, the natural product. It is stated that
before a single pound of synthetic indigo was placed on the
market over 1,000,000 had been spent during the twenty years.

THE INDUSTRY IN THIS COUNTRY 309

The literature, patent and otherwise, upon the subject is one of
the finest chapters in the history of chemical technological re-
search. It is not my intention to enter into the details of this
magnificent work time will not permit, and most of you are
familiar with it. Had the indigo planters not been so sure of
their position, they would when the first discovery of synthetic
indigo was announced in 1878 have carried out experiments to
see if they could not improve the quality and quantity of their
product, but they sat by with folded hands. When it was too
late they cried out that the introduction of synthetic indigo was
a bolt from the blue. They should have watched the signs, in
which case they would not have been so surprised ; aye, they
might even have arrested or retarded the falling of the bolt.

I have given some of the chief reasons why the artificial colour
industry was lost to this country. There is, however, another
one. In the preparation and purification of some of the dyes, it
is necessary to employ large quantities of pure alcohol. The
enormous cost of pure alcohol in this country, compared to its
cost in Germany, owing to Government duty and excise re-
strictions, has made its use on a large scale prohibitive, and has
most certainly been a contributory cause in helping the German
manufacturers. Within the last few years these restrictions
have been considerably mitigated largely owing to the per-
severing efforts of Mr Thomas Tyrer. Unfortunately, much yet
remains to be done. Although Government has given relief,
the officials who have to administer the Government Acts seem
to forget they are public servants, placed there for the good of
the country. Several manufacturers to my knowledge, after
inquiring into the matter, found the use of alcohol so hedged
and bound about with red tape and officialism, that they were
unable to take advantage of the Act. In the fine chemical trade,
that is the manufacture of drugs and photographic chemicals,
the use of pure alcohol is of even greater importance than in the
colour industry. The fine chemical trade in synthetic drugs and
photographic chemicals never has been a British industry. It is
entirely due to German research work, and we have never tried
to develop it here. It is, however, a very important industry,
and there is no reason why it should not now be developed, at
any rate in a partial state, in this country. Alcohol, however, is
a very important reagent for this industry. British manufacturers
can produce good cheap alcohol, if there is a demand for it ; but

310

THE BRITISH COAL-TAR INDUSTRY

while its use is hedged with difficulties, those who use it will
employ it in minimum quantities only. Like most commodities,
it can be made more cheaply in large than in small quantities.

Let me now briefly summarise the causes which have led or
contributed to the present position of the artificial colour industry
in this country :

(1) The character of the British patent laws and the want of

patent laws in Germany, whereby the Germans were
able to exploit our brains.

(2) Slackness on the part of the early British manufacturers

(after a certain period of prosperity).

(3) Industrial chemical research carried out in Germany, but

neglected by us.

(4) German business organisation.

(5) Restrictions on the use of alcohol.

That the artificial colour industry is in a bad position is self-
evident. A devastating war has broken out, stopping our supply
of imported colours, and what is the result ? There is a dye
famine. Dyers cannot carry out their contracts because, although
willing to pay almost any price, they cannot obtain the dyes. It
must be remembered also that aniline dyes are used for a great
many purposes other than that of dyeing textiles. Paper, leather,
bones, feathers, straw, grasses, etc., are all dyed with aniline dyes.
They are employed for dyeing wood, particularly in the furniture
trade. Very large quantities are used in paints in the form of
lakes. Even in confectionary they are employed. All these
industries are hit.

So dependent, indeed, are our manufacturers upon dyes, that
the stoppage of the supply is beginning to cause great distress
amongst thousands of our workers, and this distress will increase
as the available supplies are used up. Colonel H. A. Foster
recently pointed out, before the Bradford Chamber of Commerce,
that although the value of the dyes imported might not exceed
2,000,000 to 3,000,000 per annum, yet taking textiles alone
it involves indirectly a turn-over of about .100,000,000. If we
take into account some of the other uses which I have mentioned,
this enormous sum must be greatly exceeded.

The British colour makers are increasing their output, but
since before the war they were supplying only about 1 5 per cent.
of the amount used in the United Kingdom, it is obvious that

THE INDUSTRY IN THIS COUNTRY 311

they will not be in a position for a long time to meet the demand.
Furthermore, the Germans manufactured very large quantities of
dyes which have never been made here.

What, then, is to be done ? I notice that the Bradford
Chamber of Commerce unanimously passed a resolution on
2 yth October "urging upon His Majesty's Government the
vital necessity for immediately adopting measures for furnishing
such support as is essential to the establishing and effectual con-
tinuance of the manufacture of aniline dyes upon an adequate
scale in this country."

To my mind, the most important part of the resolution is
contained in the words " and effectual continuance of the manu-
facture of aniline dyes." If the industry is founded, it is the
bounden duty of the Government to see that it is not stifled
again at the end of the war.

Capitalists who might be willing to risk their money in putting
up colour works say : But what is to happen after the war ?
The Germans will again flood the market and undercut. In all
probability they have accumulated supplies and will be willing to
get rid of them at almost any price. Will the Government
guarantee that for a certain number of years all dyeing which is
done for Government Departments shall be dyed only with
British-made dyes ? If the Government agree, and the manu-
facturers and users of this country should compel them to agree,
what about other than Government users ? Will they rush back
to buy in the cheapest market, because it goes without saying
that in most cases, for some time at least, the British dyes will
not be so cheap as the German, owing to the enormous experience
the latter have behind them. On the other hand, in our gas-
works we have a great deal of the raw product necessary.

My own feeling is that a large portion of the raw products
should be made by some of our large gas-works, that is to say,
those which have tar-distilling plants. They have there, in their
works, the benzol, toluol, naphthalene, anthracene, etc. With
regard to the last-named substance anthracene the British
Alizarin Company can probably deal with it better than anyone
else, but they will require increased supplies.

Why should not nitrobenzene, aniline, nitrotoluene, toluidine,
the naphthols, naphthylamines, phthalic anhydride, and many
other substances, which are the raw materials for the colour
works, be made at the source of supply of the raw products for

312 THE BRITISH COAL-TAR INDUSTRY

their manufacture ? About 10,000,000 gallons of benzene are
produced annually, and before the war two-thirds of this went to
Germany, a portion of which they used for making aniline.

The question is one bristling with difficulties, but it is of
instant urgency. Some suggest the establishment of huge works
comparable to those of the Badische or Meister, Lucius &
BrUning (forgetting that those were built up from comparatively
small beginnings), which will manufacture every type of colour
and also fine chemicals, a scheme which would mean in the long
run a huge financial disaster. Others think that a number of
small firms should be founded which would manufacture certain
specific ranges of colours. This certainly is more feasible.

My own feeling is that those firms now manufacturing should
enlarge their output and obtain leave to work certain German
patents ; that many of the raw products should be manufactured
at one or two of the great gas-works who might, after their plant
was working, also make certain dyes and gradually branch out ;
also that a few new companies with carefully thought-out pro-
grammes should be started.

Now in connection with the protection of the industry I wish
to say another word. We will presume that the Government
will only allow the use of British-made dyes. How about the
other consumers ? It will be very difficult to bind them. The
best solution of the problem would be to give them, or rather
get them to take, an interest in the new works, or, for a matter
of that, in the old ones. This was done by the Turkey Red
Dyers' Association, who, in order to prevent the manufacture of
alizarin leaving the country, founded the British Alizarin Com-
pany, and agreed to take so much of the output. They were
thus not dependent upon the Germans, and also had an interest
in the manufacture of the product. Cannot the general dyers do
something similar ?

In conclusion, I wish to say just one word as to the revocation
of German patents. After war was declared, the Home Office
revoked all German and Austrian patents, as and during the
continuance of the war. It was also stated that in certain cases
licences would be granted to British manufacturers to take up
and work these patents. I was informed recently by an eminent
patent lawyer and by one of the largest patent agents in London,
that the granting of licences is practically a dead letter. Further,
that where licences have been granted, a royalty is reserved for

THE INDUSTRY IN THIS COUNTRY 313

the enemy, and there is no certainty that those who have obtained
a licence during the war will be allowed to work the patent after
the declaration of peace.

If the trade is to come to this country, and to be retained by
it, it is of vital importance that these matters be cleared up, and
the Government must help.

DISCUSSION

The Chairman (Mr E. HICKSON) said many people seemed to
think that the colour trade in Germany had been fostered and
helped by the Government in a manner which was quite out of
proportion with the truth, and those of them who had seen the
little jubilee books recently issued by some of the German firms
who had celebrated their fiftieth anniversary would know quite
well how true was the lecturer's statement that most of these
firms started on the most insignificant scale.

The Lord Mayor of Leeds (Mr J. E. BEDFORD) said it was
particularly interesting to hear the early history of this subject
from the lips of one who bore the honoured name of Perkin.
He thought it was their duty to recognise the scientific and
business-like manner in which Germany had conducted and
developed this important industry. When the present crisis
developed, the Government had very promptly set up at the
Board of Trade a Chemical Products Committee, and called
together eminent business and scientific men to discuss the
matter, and see how the stoppage of the textile and printing
industries could be avoided. Some of them had taken the view
that it would be absolutely necessary, in order to build up and
foster this industry, for the Government to give some form of
protection. He himself had suggested at a meeting of the Leeds
Chamber of Commerce that we should have to put a protective
duty of about 25 to 30 per cent, on imported aniline dyes, and
his friends had reproached him with the fact that he was a
Liberal Free-trader, and was now turning Conservative. He
had replied : " 1 am still a Free-trader, but in extraordinary
circumstances and in time of war you must adopt war methods.''
He believed they had in England a sufficient number of highly
trained chemists to develop the industry. He was sure that
there were certain of the simple colours which could be tackled
at once if the requisite amount of capital were available.

3 14 THE BRITISH COAL-TAR INDUSTRY

Professor W. M. GARDNER said one point which appeared to
him worthy of mention, and which was not included in the list
of reasons given for the loss of the industry, was perhaps a
fundamental one. Dr Perkin had to some extent touched upon
it when he mentioned that in the development of the synthesis
of indigo upwards of 1,000,000 had been spent in experiment
before any return was obtained. It appeared to him that this
would have been quite impossible in England, because the
investing public would never have supported an expenditure of
any such sum. Want of knowledge and of interest on the part
of the investing public had been one not unimportant cause why
companies had not been formed for the development of the
industry in this country. There were other reasons why it was
peculiarly difficult to regain the industry, and here again he
should like to touch upon a point which the lecturer, no doubt
from lack of time, did not mention ; and that was the important
way in which secondary and subsidiary interests had been built
round the great coal-tar colour industry of Germany, such as
the manufacture of synthetic medicines and synthetic scents and
flavourings on the one hand, and the manufacture of necessary
reagents, such as fuming sulphuric acid, on the other. These
had put the industry in Germany in an extremely strong position,
since before we could hope successfully to compete with them
we should have to launch out, not only in the manufacture of
colours, but in many other directions, so that altogether an
enormous outlay of capital would be required. The public must
recognise that it was a most complicated question, and one which
would require not only great enterprise and co-operation on
the part of manufacturers and consumers, but would inevitably
require assistance from the Government.

The Lecturer said the subject was so big that he was afraid of
digressing on side issues, but he quite agreed with Professor
Gardner that one of the reasons why the industry had become so
great in Germany was the working up of by-products. What
was waste in one product was the starting-point in making
another product, and if they were going to manufacture
successfully in this country they must pay attention to that fact.
It was no use saying they would manufacture this or that dye
and neglect all its by-products. If they did, the cost of the dye
would be out of all proportion to its cost as it was manufactured
abroad.

XXIV.: 1914

THE SUPPLY OF CHEMICALS TO BRITAIN
AND HER DEPENDENCIES

BY SIR WILLIAM A. TILDEN, D.Sc., LL.D., F.R.S.

(Journal of the Royal Society of Arts^ 2Jth November 1914, p. 26)

To those who can look back over half a century, the progress
of scientific and industrial chemistry, and the relations of the one
to the other, present many features of extreme interest. After
the days of Lavoisier, and during the earlier part of the nineteenth
century, the foundations of theoretical chemistry were laid by the
efforts, contemporaneous but independent, of the chemists of
England, France, and Sweden. The great names -associated
with the movement include Davy, Faraday, Dalton, Gay-Lussac,
Dumas, and Berzelius. There were no German chemists of the
first rank in those days, and if we look among them for funda-
mental discoveries we can only find one of considerable import-
ance, namely, the discovery of isomorphism by Eilhard Mitscher-
lich in 1819. But the birth of Justus Liebig at Darmstadt, in
1803, gave to German science a leader whose influence stretches
down to our own day, and is felt wherever chemistry is studied or
practised. The department of organic chemistry has been the field
in which the most remarkable successes have been won, though
not wholly, as sometimes represented, by the German chemist.

The relation of optical activity to atomic constitution was the
discovery of le Bel, a Frenchman, almost simultaneously with
van 't Hoff, a Dutchman, and the application of their theories
to the phenomena presented by compounds other than those of
carbon was illustrated in the first instance by Smiles, and by Pope
and Peachey, all of whom are Englishmen. It will also be only
fair to state that while we readily acknowledge with admiration
the brilliant work of von Baeyer and Emil Fischer in connection

315

3 i6 THE BRITISH COAL-TAR INDUSTRY

with the synthesis of indigo, the sugars and the proteins, the
fundamental principles which underly all chemical theory have
been established almost entirely by the chemists of other nations.
It is only necessary to recall such subjects as the atomic theory,
the periodic law, Faraday's laws of electrolysis, the theory of free
ions, the phenomena of radio-activity, and the discovery of radium,
to show that in laying down broad general principles German
chemists have not usually been the first in the field, though at
later stages they have shown great and commendable activity.

Turning now to the position of industrial chemistry, a single
brief quotation from the " Report on Chemical and Pharmaceutical
Products and Processes" in the International Exhibition of 1862,
from the pen of A. W. Hofmann, then Professor of Chemistry
in the Royal College of Chemistry and Royal School of Mines,
London, will be sufficient. He says (p. 3) : " The contributions
of the United Kingdom, and in particular the splendid chemical
display in the eastern annexe, prove the British not only to have
maintained their pre-eminence among the chemical manufacturers
of the world, but to have outdone their own admitted superiority
on the corresponding occasion of 1851."

On referring to the table of statistics which appears on the
same page of the report, we find that of the 762 exhibitors in
the class, the United Kingdom was represented by 200, while
Germany, Austria, the Zollverein, and the Hanse towns together
mustered only 136. France stood next with 115 exhibitors. It
will be remembered that at the date of the exhibition the dis-
covery of the so-called aniline colours was bearing very important
industrial fruit. Mauve, or aniline purple, was discovered by
W. H. Perkin in 1856, and aniline red was first obtained
industrially by Verguin and Renard Freres of Lyons a few
years later.

It is also interesting to notice that among the early investi-
gators and patentees of processes connected with the production
of colour from coal-tar hydrocarbons, only English and French
names are to be found, with the significant exceptions of Hofmann
and Caro, both of whom were at that period resident in England.
At this time synthetical chemistry in the modern sense was as yet
unpractised because unknown. Such an important substance as
salicylic acid, for example, was a mere laboratory product, obtain-
able only from natural sources.

But the activity of the chemical industries in the United

THE SUPPLY OF CHEMICALS TO BRITAIN 317

Kingdom is not to be measured only by reference to subjects
such as those of the coal-tar colours, nor by the number of
exhibitors in an international exhibition even at that early period
in the history of exhibitions, at which manufacturers were far
more eager to find a place than they have been in more recent
times. Statistics in relation to the development of the alkali
trade show how rapidly the production of what are called " heavy
chemicals " was proceeding at this period. Figures derived from
returns collected by Mr Christian Allhusen from 8 1 per cent, of
the manufacturers in the United Kingdom, immediately after the
first Great Exhibition, are shown below. These may be compared
with statistics prepared by Mr W. Gossage for the year 1861,
immediately before the Exhibition of I862 1 :

1852.

1861.

Tons.

Soda ash ....

71,193

156,000

Soda crystals ....

61,044

104,000

Bicarbonate ....

5>762

13,000

Bleaching powder .

13,100

20,000

The value of these products for 1852 was estimated at about
ij million pounds, while the value of the products of 1861 was
calculated by Mr Gossage at upwards of two millions sterling.

The Board of Trade has recently issued a Bulletin concerning
German competition in the United Kingdom market, and on
page 2 we find the statement that the soda compounds, excluding
chromates and bleaching powder, produced in the United
Kingdom in the year 1907, are valued at 3,390,000. The im-
ports from Germany in 1912 are valued at only 8700. As
to bleaching materials, the product of the United Kingdom for
1907 is estimated at 527,000, while the import from Germany
for 1912 was 44,600.

From these figures the easy deduction is made that "the
imports of these chemicals into the United Kingdom from
Germany are relatively insignificant when compared with the
output of the same articles in this country. It is clear that in
these particular lines British manufacturers have no need to
fear German competition in the home market."

1 Gossage's History of the Soda Manufacture.

318 THE BRITISH COAL-TAR INDUSTRY

Similar remarks apply to aluminous compounds, coal-tar
products not dyes, the cyanides, sulphuric acid, and other acids
for which the Bulletin may be consulted. It thus appears that
the British manufacturers of sulphuric acid and soda, from the
early times of a century ago, have been able, up to the present,
to hold their own against foreign competition, and have thus
added substantially to the revenues and well-being of their
country.

The immense advances in every direction made in all
civilised countries have brought demands in steadily increasing
quantities for a variety of materials of which many were unknown
to the generations immediately preceding our own. These are
almost all the outcome of the progress in our own time of
chemical knowledge. Since the introduction of the coal-tar
dyes the development of chemical theory has rendered possible
the production in the laboratory of a large number of organic
substances which are either identical with compounds already
known as occurring in Nature, or from their ascertained physio-
logical action' have added incalculably to the resources of the
physician and surgeon in relieving pain and in curing disease.
These include not only drugs for internal administration, but
antiseptics, the use of which was only beginning to be recognised
at the time of the Exhibition in 1862 (Hofmann's Report,
pp. 104-105).

To these must be added essential oils and other volatile
aromatic substances, the application of which to perfumery and
flavouring has undergone a stupendous development during the
last thirty years.

The innumerable applications of photography have also
led to a deniand for developing, fixing, and toning materials, as
well as for plates and films on a very large scale.

The arts of peace as well as the operations of war have also
led to the production of explosives of many new types formerly
unknown.

There is also another department of business which requires
notice, and that is the demand for pure chemical reagents for
analysis and research, which has increased to an extent very
difficult to calculate, but is manifestly very large. The modern
university and technical colleges, nearly the whole of which have
come into existence within the last forty years, the large body
of Public Analysts appointed under the Sale of Food and Drugs

THE SUPPLY OF CHEMICALS TO BRITAIN 319

Act, 1875, the establishment in nearly all the public schools and
high schools of laboratories for teaching chemistry, as well as
the numerous technical laboratories connected with such in-
stitutions as the Government Laboratory, the National Physical
Laboratory, the Metropolitan Water Board, and many others,
afford sufficient evidence that there are several hundreds of
chemical laboratories distributed over the United Kingdom in
which pure chemicals are required for analytical purposes.

Now, leaving to the department of " heavy chemicals " all
such things as agricultural and horticultural washes, coarse disin-
fectants and artificial manures, the question arises : How do
we in England stand in regard to the supply of drugs, dyes,
photographic chemicals, and perfumes at a time when many of
these things are very urgently needed ?

It may be safely asserted that the sources of supply of all
these materials in the United Kingdom are seriously inadequate.
And, further, we may point to the acknowledged fact that many
of the dyes, and nearly all the synthetic drugs and photographic
materials have been systematically imported from Germany.

The Annual Statement of the Board of Trade (p. 108) shows
that in 1913 we imported from Germany :

Alizarin and anthracene dyes . . . . 271,119
Aniline and naphthalene dyes . . . 1,382,478
Synthetic indigo 76,681

1,730,278

Under the head of " Drugs, unenumerated, including
Medicinal Preparations " (p. 107), out of a total of imports from
foreign countries and from British possessions amounting to
1,302,860, more than one-fourth, or to the value of 332,464,
was in 1913 received from Germany. From this is to be
deducted the inconsiderable amount of dyes and other chemicals
from coal-tar, valued at 24,691, exported in 1913 to Germany
(p. 300). According to the Final Report on the First Census of
Production of the United Kingdom for 1907 (p. 547), this
country made 139,000 cwt. of coal-tar dyes, valued at 373,000,
of which practically the whole was consumed at home.

As to fine chemicals for analysis and for research, there are
no figures available, but it may safely be said that there has been
no appreciable production of these things in this country. If

320 THE BRITISH COAL-TAR INDUSTRY

such a statement is met by protests from manufacturers who pro-
fess to supply these materials it is only necessary to refer to
the experience of analysts and directors of research laboratories,
which has compelled many of them to resort habitually to
German makers for their supplies of trustworthy reagents.

If we are ever to be in a position to supply ourselves and
our dependencies with the dyes, the drugs, and the rest of the
fine chemicals required in our work, it will only be achieved after
a careful review of the circumstances which led to the removal
of the industries from this, the country in which many of them
originated, together with a determination to take to heart the
lessons of the past.

A chemical manufacturer, discussing the neglect of fine
chemicals in this country, recently made the remark : " What
does it matter, if we are making money ? " I venture to say
that that view expresses neither patriotism nor common sense.
For the same principles which have served as the basis of the
German success in relation to dyes and fine chemicals apply
equally to the production of heavy chemicals, and already
German chemists have been boasting that, having secured the
trade in the former, they are about to attack the latter.

The export trade in sulphuric acid alone is already three
times as great from Germany (1912) as from the United Kingdom
(1913), as shown by the figures given in the recent Bulletin
issued by the Board of Trade (Commercial Intelligence Branch,
October 1914).

The recent success of Professor Haber, of Karlsruhe, in
the synthetical production of ammonia from hydrogen and
atmospheric nitrogen, a process which has been put into opera-
tion on an industrial scale by the Badische Company, ought
surely to carry something significant to the unprejudiced mind.
Neither is it superfluous to point to the extensions taking place
in several countries of operations in which the nitrogen of the
atmosphere is being fixed in the form 4 of cyanamide, of nitrites
and nitrates in which the industrial lead has been taken by
Germany, which also supplies a large proportion of the capital,
though at present not to the exclusion of the British.

The extent to which the German chemist arrogates to himself
the whole field of scientific and industrial chemistry is illustrated
in the report (given in full of Nature, Ixxxv. p. 558) of a lecture
given by Professor Emil Fischer on nth January 1911, in the

THE SUPPLY OF CHEMICALS TO BRITAIN 321

presence of the Emperor, on the occasion of the inauguration of
the Kaiser Wilhelm Gesellschaft zur Fflrderung der Wissen-
schaften. It is at least unpleasant to hear of a man so eminent
as Professor Fischer, and so worthy of respect, treating the
subjects of his discourse as though every one of them had
originated and been developed in Germany. Perkin is indeed
referred to as the discoverer of mauve, but every other foreign
name is omitted.

If I now try to recall some of the circumstances which led
to the gradual transference of the colour industry from this
country to Germany, and the failure to establish here any
appreciable production of the synthetical drugs and other
chemicals now so urgently needed, it will not be the first time
the facts have been stated and the obvious conclusions deduced
therefrom.

All the substances referred to belong to the department of
organic chemistry, and it might perhaps be supposed that neglect
of this branch of the science by the chemists of this country was
the cause of the loss of business. When Hofmann was un-
fortunately allowed to leave the College of Chemistry to return
to his own country, a check was for some time observable in the
output of research among us, but it must be remembered that
the number of institutions in all countries in which the study
of chemistry was pursued was then relatively small. Even in
Germany the Chemical Society in Berlin did not come into
existence till 1867, anc ^ U P to tnat time th ere had been no
laboratory for practical instruction in chemistry in the university
of that city.

For the last thirty years, however, the progress of research
in this country has gone forward at an increasing rate, though
still less rapidly than in Germany. The slow development of
chemical teaching and research in this country was attributed
by many people to the anti-scientific influences at work in our
universities, and especially the older universities. This point
of view was exposed very clearly and forcibly by the late Sir
William Perkin in presidential addresses delivered to the
Chemical Society and the Society of Chemical Industry in 1885
(see p. 75, ante). And up to this time it would be indeed difficult
to exonerate Oxford and Cambridge from responsibility in the
evil example shown by those great seats of learning. But since
that day many changes have taken place, and great advances

3*2 THE BRITISH COAL-TAR INDUSTRY

have been made. What is wanted in the British universities
is, first of all, that no man shall in future be appointed to a
professorship, or indeed to any teaching post in connection with
physical or natural science, who does not show his ability to
instruct in the higher branches of his subject by the character
of the researches which he continues to carry out during his
tenure of office ; and, secondly, such a change in the curriculum
and endowments that there may be not only a supply of
instruments and materials but a sufficient body of trained
assistants in the form of advanced students to enable the
professor to pursue without delay any promising line of
investigation.

Notwithstanding the difficulties which stand in the way the
scientific chemists of this country are, however, not idle.
Evidence of this may be seen in the Transactions of the Chemical
Society , the volume of which for 1913 contains 238 papers
extending over more than 2300 pages. And when it is
remembered that these papers have survived the severe
censorship exercised by the Publication Committee of the
Society the result must be considered encouraging. It appears,
then, that it is not to the scientific part of the chemical world
that blame attaches in recent times.

Forty years ago it would be safe to say that there were

practically no chemists engaged in the direction of the chemical

works or this country, and by chemists I mean fully qualified

scientific men. Probably in the palmy days of colour-making it

would have been difficult to meet with a British manufacturer

who had ever heard of Kekule's benzene theory, or would have

thought it worthy of a moment's notice by a practical man.

And yet at the Kekule Jubilee in 1890 a representative of the

German coal-tar colour industry declared that the prosperity of

Germany in this direction was primarily due to this theoretical

conception. Even in much later times the chemical manufacturer

in this country has repeatedly had facts laid before him which

ought to have attracted his serious attention. One of the most

convincing statements was laid before this Society by Professor

Meldola on I3th May 1886 (see p. 121, ante\ and one would

suppose that the figures then given would have been sufficient

to create well-founded alarm. For he showed, on the testimony

of a considerable number of prominent English dyers, that

already about nine-tenths of the colours employed by them were

THE SUPPLY OF CHEMICALS TO BRITAIN 323

imported from Germany. Again, in a lecture given before the
British Association in 1901, on the "Relative Progress of the
Coal-tar Industry in England and Germany during the Past
Fifteen Years " (see p. 189, ante). Professor Green showed clearly
the steady increase in the imports of dyestuffs from Germany
into England, and the steady decline in the production of similar
materials in England.

Finally, we have the fact known to all the world that one
of the most notable triumphs of German chemical industry is
the production of synthetic indigo made from naphthalene on
a scale so large as to have almost driven the Indian planter from
the field. In this case we have over again a story nearly
corresponding to the history of the introduction of artificial
alizarin in 1869, an event which was speedily followed by the
abandonment of the cultivation of madder in the south of
France and elsewhere. And to-day we learn from the Board
of Trade Statement for 1913 that we imported indigo from
Germany to the value of ^76,681, while the value of the
natural indigo from India has declined from ^124,1 12 in 1909
to ^48,208 in 1913. As to the cause of this serious reduction
of chemical business authorities are unanimous.

Perkin, in the address to the Chemical Society already quoted,
attributed the success of the German industries to the employ-
ment of high-class chemists (Trans. Chem. Soc., xlv. [1884],
p. 219 et seq.}.

The same view was expressed by Professor Meldola in his
paper before this Society in 1886. "The strength of our
competitors," he says, " is in their laboratories and not, as here,
on the exchanges."

Professor Green stated as his opinion, in the lecture referred
to, that the remedy for the present state of affairs can only be
found in a better appreciation of the value of science throughout
the length and breadth of the land, and that it is not so much
the education of our chemists which is at fault as the scientific
education of the public as a whole. Nor can much improvement
be expected till the public, including manufacturers, can be
disabused of the fallacy that a year or two of technical training
pumped into an ignorant schoolboy will produce a better works
chemist than a university course of scientific study laid upon the
foundation of a good general education.

If these are supposed to be merely the prejudiced opinions

3 2 4

THE BRITISH COAL-TAR INDUSTRY

of British chemists, the sentiments expressed by German manu-
facturers themselves may be appealed to.

In 1900 a lecture was delivered on the occasion of the
opening of the Hofmann House in Berlin by Dr H. Brunck,
since 1884 chief technical director of the Badische Company, on
the "History of the Development of the Manufacture of Indigo "
(see p. 204, ante). This lecture, in the form of the English
version issued by Dr Brunck, may be fairly regarded as a sermon
preached to British manufacturers. Its perusal will convince
anyone that the success which has been achieved is the reward
of long-sustained investigation in the laboratory of the scientific
chemist, and to do justice to this conviction I wish every chemical
employer in this country could be induced to read the weighty
and eloquent words of the author. He would then perceive
that to permanent industrial success there is only one road, and
that the way pointed by science.

I will content myself with quoting only a passage or two
from Brunck's lecture :

" With grateful admiration and reverence do we recall those
ever memorable masters, Kekul6 and A. W. von Hofmann,
whose gifted achievements have laid the foundations of our
industry. And when we look back at all the technical achieve-
ments we also gratefully recall the fertile discoveries of Graebe
and Liebermann, of Peter Griess, and the beautiful researches
of Emil and Otto Fischer, of O. N. Witt, and the numerous
other investigations conducted in our university laboratories,
which have acted as incentives for chemical industry, and have
furnished the foundation for renewed progress. But first and
foremost we are impressed by the mighty influence of the
investigations of A. von Baeyer, to whom the coal-tar colour
industry is indebted for a great number of important achieve-
ments, and who himself has, to-day, unfurled before you the
picture of a magnificent scientific creation, from which it was
possible for chemical industry to construct and develop one of
its grandest achievements.

" But this infant industry was no longer content to be
dependent on the gifts which were made to it from various
scientific sources. Renowned investigators placed themselves
entirely at the disposal of chemical industry ; young men in
great numbers devoted themselves to it, and grew up with it
in enthusiastic and self-directed activity. Such men as Caro,

THE SUPPLY OF CHEMICALS TO BRITAIN 325

Glaser, Martius, and later on Laubenheimer, Duisberg, Bernthsen,
and many others, introduced the spirit of scientific investigation
into industrial practice." And, in conclusion, he says : " You
have seen that this new industry is not an unexpected gift fallen
from the heavens, but that in order to complete the task the
intellectual labour and the industry of many men had to be
co-ordinated in an organised attempt to attain a definite object
for a number of years and throughout a considerable period
when success could by no means be regarded as certain. The
pre-requisites for practical indigo synthesis were supplied by the
results of long years of scientific labour."

In the semi-annual report for April 1903 issued by
Schimmel & Co., the famous manufacturers of essential oils,
there are some figures which show the increase of chemical
works in Germany and the great increase in the numbers of
qualified workmen employed therein, on which the firm makes
the following remark : " The foregoing figures show clearly
that the German chemical industry has passed intact through the
economic crisis of the last few years. Further, there are no
grounds for fearing that it will be outstripped by competition
from abroad, so long as the German universities possess such
eminent representatives of chemical science."

It is now time to consider what ought to be done and what
it is possible to do in this country to remove reproach from
British chemical industry, and to render the Empire independent
of supplies from foreign sources.

We need many first-rate chemists, a few engineers, plenty of
capital, and some good men of business. A combination of these
elements in due proportion is certain of success, and the time,
though so unhappy for the world, is favourable for this enterprise.

Inasmuch as the functions of each and the best way of com-
bining them have already been settled in practice on the Continent,
it is to be hoped that the ancient precept about being taught by
the enemy -fas est et eb hoste doceri will not be forgotten. For
there can be no doubt that the principle acted on in all German
chemical factories, namely, the employment of the best available
scientific skill and the constant appeal to scientific research, has
been the secret of their success.

In the British colleges and universities there are many able
young chemists, but many more are required. Here education
and industry interact on each other. If the demand for scientific

326 THE BRITISH COAL-TAR INDUSTRY

assistance were more general, the supply of well-qualified men
would soon be greatly increased, and greater attention given by
the teachers to the industrial side of the subject. At present
other professions in which the prospects are more alluring attract
into other lines of work much of the talent of the country.
This, however, is not to be interpreted as meaning that there is
not now a supply of able young chemists sufficient for immediate
needs. The difficulty is to induce chemical manufacturers to
treat them reasonably. The pay offered is generally insufficient,
and though conditions are somewhat improved of late years, the
employer too often expects immediate profitable returns from the
engagement of a scientific man. In the Badische works at
Ludwigshafen the plan has been to engage university men on
the recommendation of their professors for a term of years, at a
salary which will enable the new members of the staff to live at
least modestly. I am told that in some American works the same
system has been adopted. These young men are placed in the
research laboratory under the chief chemist controlling the de-
partment of manufacture selected, and it is not expected that they
will accomplish anything very remunerative at first. But their
future depends on their ability and activity, and they act
accordingly.

Then there is the position to be accorded to the engineer.
He is, of course, indispensable ; but the part he should play in
the works depends on the nature of the processes involved. So
far as relates to buildings and other structures, to supplies of
water, fuel, power, and electricty, the engineer has the field to
himself, but the operations in which materials are to be employed
in producing and controlling chemical reactions which lead to the
desired product belong to the chemist, and here he ought to be
supreme. In some of the old-established operations an engineer
with an elementary knowledge of chemistry may carry on fo a
time, but in these days a chemist with the most extensive and
intimate knowledge of physical chemistry is necessary if these
processes are to continue to be profitable. As to the production
of dyes and other organic synthetical products, the operations
involved are in many cases so nearly similar to laboratory pro-
cesses that the chemist requires very little assistance from the
engineer.

As to capital, it is necessary to remember that it will have to
be provided liberally. A single fact mentioned in Brunck's

THE SUPPLY OF CHEMICALS TO BRITAIN 327

lecture on indigo, given already fourteen years ago, shows the
spirit in which the German manufacturers attacked the problem
of the industrial production of this one colouring matter. They
had then invested about 900,000 for this purpose.

The works of the Badische Anilin- u. Soda-Fabrik at Ludwigs-
hafen are arranged on a plan, which clearly recognises the in-
separability of research and manufacture. A number of rect-
angular buildings, four storeys high, are so arranged that the
railway lines may traverse the works in two directions at right
angles to each other. Each building is devoted to the production
of one substance or closely allied group of substances. The top
floor is occupied by the laboratory of the chief chemist attached
to that department, with several assistants. Below is found an
intermediate floor where processes previously tested in the
laboratory, or suggested as the result of research, may be tried
on a scale sufficiently large to determine their practicability before
being transferred to the lower floors where the actual manufacture
is conducted. I doubt if anything so complete or so commercially
successful exists elsewhere in the world.

How many chemical manufacturers among us can boast
that they regard science in a light so serious as to have pro-
vided in their works a properly equipped laboratory with a com-
petent staff whose occupation is not confined to the analytical
testing of materials or products, but extends to the systematic
endeavour to introduce improvements into old methods or the
discovery of new ones ? A few such enlightened firms do exist,
but the figures quoted show how much mischief has already
been done.

A variety of other questions have recently been raised in view
of the circumstances which have been forced on our notice by the
war. There is not time for the discussion of the state of the law
as to patents, but a couple of sentences in Schimmers report for
April 1908 show that "great alarm has been caused in the whole-
sale chemical industry of Germany by the new British Patent
Act, which came into force on ist January 1908, according to
which every patent may be declared void if it is exclusively
exercised abroad without sufficient grounds. Many firms are
thereby compelled to transfer a part of their production to the
United Kingdom, a fact which, in the interests of many thousands
of German workmen, is sincerely to be regretted. "

With regard to duty-free alcohol, I am informed, on the best

328 THE BRITISH COAL-TAR INDUSTRY

authority, that the regulations in this country are now compar-
able with those of the German Government, and that there is
very little ground for complaint. In the vast majority of cases
suitably denatured alcohol can be employed without loss or
inconvenience.

There has been a good deal of discussion on the subject of
trade-marks and proprietary names, much of which I regard as
futile. With regard to drugs, there should be no great difficulty
in instructing the medical profession in those comparatively few
cases in which the names are changed.

In conclusion, two remarks only require to be made. The
establishment of what will be practically a new industry in this
country will require consideration and assistance from the State,
if it is to survive the period of fierce competition which will
follow the conclusion of the war. Encouragement is already
promised to the dye industry, in the form of definite financial
aid to be given by Government. But remembering that the
colour-maker is dependent on the production of many chemi-
cals, which represent intermediate stages in the processes which
lead from the raw materials to the finished product, and that the
production of these chemicals is naturally associated with other
chemical manufactures, it is to be hoped that the temporary
production will be extended beyond the immediate field of the
colour-maker.

The other remark may raise a smile on the part of those
business men who are moved only by commercial considerations.
There will be a great temptation when the war is over to resume
former business relations with the enemy. The German chemical
manufacturers have a powerful organisation and many years of
experience behind them. Let them keep any markets they can
retain outside the British Empire, but every man who cares for
his country will surely demand that business at home shall be
limited to British goods.

DISCUSSION

The Chairman (Sir WILLIAM RAMSAY), in opening the dis-
cussion, said the paper emphasised what we had been told so
often during past years, that too little attention had been paid
to the scientific side of chemical manufacture in Great Britain.
But there were two aspects of the question which had not, he

THE SUPPLY OF CHEMICALS TO BRITAIN 329

thought, been sufficiently touched on. The first aspect was as
follows : Trade was regarded in Germany as a war ; all means
of conquest were looked on as permissible. At the annual
meeting of the Society of Chemical Industry in 1903, he had
said : " It was the Prussians who first showed how a modern
army should be organised . . . they have at Berlin a council
which arranges each particular of each possible campaign ; the
men are known who will take the command, and from rank to
rank the knowledge is spread as to what particular part each
officer and each man will have to play in the campaign. The
matter is not left to chance. . . . An exactly similar policy is
being pursued by Germany in the matter of industry. It would
be curious if it had not occurred to the persons who are respons-
ible for the military organisation of Prussia that a similar policy
is applicable to commerce. It would be remarkable if, having
succeeded so well in their military organisation, no attempt had
been made to establish a similar commercial organisation ; and
we shall not go wrong if we assume that there is a council whose
proceedings are kept quiet but which takes into consideration the
statistics obtainable, and as far as possible legislates, or endeavours
to legislate, on the basis of these statistics. Where fiscal duties
are found to be wanted, such a council puts them on ; where
there is an advantage in taking them off, they take them off.
Where cheap transit is possible, they let it be given ; for the
railways are the property of the State. Is it to be expected that
any country can fight such a combination as that without adopt-
ing, at all events, something of their methods, or without study-
ing their methods, and without combining together, if not to
imitate them, at all events to thwart them ? " He had put the
second aspect of the case in a leader in Nature ', on i2th Novem-
ber 1914. He would quote it. Dealing with the organisation
of a German chemical business, he pointed out : " First, the
management consists, not in a board of well-meaning elderly
gentlemen with a works-manager in their employment, but in a
board of specialists, whose business in life is to manage the factory
financially, chemically, and as engineers, and who are very highly
paid for their services. Second, these gentlemen and a special staff
are continuously on the look-out for any scientific discovery or
invention which can prove of advantage to their business. Third,
a very large staff of men, trained in universities or technical
schools, is turned on to the problem of making such a discovery

330 THE BRITISH COAL-TAR INDUSTRY

commercial, whether by securing cheap raw material, cheapening
the process of manufacture, or creating a public demand for the
article to be manufactured. Fourth, a legal staff is maintained,
whose business it is to protect by patent all improvements,
however apparently trivial, and to describe them so vaguely as
to conceal them from their competitors ; these gentlemen, in
some cases, have also to advise whether piracy is likely to be
successful : whether it may not be possible, by infringing a
patent, so to saddle an opponent with legal expenses as to break
his competition. Fifth, such companies are so powerful that
they can influence the central Government to protect all new
developments, whether by imposing duties on articles which
might possibly compete, by extending bounties to exported
products, or by securing advantages in freights to the coast, and
in shipping the goods abroad. Sixth, agencies are maintained all
over the world whereby the article is introduced to the notice of
foreign purchasers ; and last, an extensive credit system is
encouraged." German competition was thoroughly organised
and systematic ; their plan had been to attack some material
manufactured here, and, by one of the means alluded to, to render
its manufacture unprofitable. Having obtained a monopoly, prices
were raised. That was a not unusual method of commercial
warfare ; but it was only in Germany that all the resources of
the State were combined to render it easy. How were such
tactics to be met ? First of all, there must be co-operation and
trust among our chemical manufacturers. They had to be taught
to fight, not each for his own hand, but against a common enemy.
Smaller works, which had not funds to maintain an expensive
research staff, must combine to obtain efficient laboratories. The
products of one works must supplement those of another, and
the manufacturers must be organised. Second, competition which
was unfavourable, owing to fiscal regulations or patent laws, must
be combated by the action of the State, after advice and careful
consideration, so that our manufactures and trade might not
be unfairly attacked by duties, by export bounties, or by easy
freights.

Professor JAMES J. DOBBIE thought it might confidently be
said, with regard to the supply of trained chemists, that at present
this country was in a better position than ever it had been before.
In the smallest of the Scottish universities, owing in the first
place to the munificence of a former professor, and more recently

THE SUPPLY OF CHEMICALS TO BRITAIN 331

owing to the operation of the Carnegie benefaction, a research
laboratory had been founded and endowed, which was now well
able to hold its own with any laboratory in this country, and with
many of the German laboratories. At present there were no less
than twelve students there, all of whom were in a position to take
part in work to which they had been invited by a committee of
the Royal Society, namely, assisting in the production of certain
drugs which were necessary for the Army and Navy, and which
at present could not be had from the ordinary sources of supply.
He thought that was an encouraging circumstance. As to the
capital, no one would doubt that that would be forthcoming if it
were to be employed for the particular purposes of developing
the chemical industries which had hitherto been in the hands of
the Germans. But there remained the further point : Were the
chemical manufacturers themselves ready to employ the scientific
assistance which was needed, and were they ready to remunerate it
adequately ? Unless they recognised the necessity for the em-
ployment of the highest science in the development of their
industries very little progress could be made. It was to the
education of the masters of the industry that attention had to be
devoted. He was glad the author had called attention to the
fact that this country had contributed some of the great funda-
mental principles to chemistry. There was no want of originality
in this country ; there was no want of initiative ; where we had
got behind was simply in the power of organisation, or rather the
failure to organise.

Mr A. E. BERRY said that manufacturers had not always
received the assistance and help which, in his opinion, should
have been afforded to them. A few days ago one of the com-
panies in which he was interested received an inquiry for a certain
product that had always been made in Germany. That product
required pure duty-free spirit. His company wrote to the Inland
Revenue, saying they had accepted the business and must have
duty-free spirit. That day he had received a visit from an officer
of that department, who had spent an hour and a half arguing
that the product must be made by something else than duty-free
spirit. He claimed that manufacturers in this country had the
knowledge and scientific ability to manufacture such a product,
but were debarred from doing so by the Government restrictions
with regard to duty-free spirit.

Professor A. G. GREEN remarked that the question, as the

332 THE BRITISH COAL-TAR INDUSTRY

author stated, was simply one of knowledge. The Germans had
considered it was worth their while to pay in order to obtain
knowledge ; we had not, and until we had changed our methods
we should still continue in the same old way. An instance had
come under his notice a few days previously which showed the
manner in which we were accustomed to proceed in this country.
A certain firm in the North of England, of very considerable
standing, had their attention directed to a certain substance, and
were advised it would be a very profitable thing to take up.
Instead of making inquiries as to where they would obtain the
best scientific skill and advice as to the manufacture of it, or
instead of engaging a chemist, they advertised for a workman who
had made the product. They succeeded in getting a workman,
and the man then immediately said he must have a certain raw
material. It was not to be obtained. Then they had to consider
the question of manufacturing the raw material. They then
proceeded to advertise for another workman with a knowledge
of its manufacture. He (the speaker) did not know the sequel,
but he thought it was pretty clear what it would be. Sir William
Tilden considered there were no difficulties with regard to indus-
trial alcohol at the present time. He (the speaker) was of that
opinion until a month or two ago, but from inquiries he had
made he was no longer of that opinion. The law as it stood
would, he thought, if interpreted in a liberal manner, suffice to
give all that was required, but as the law was now interpreted it
did not. For instance, the price of ether in England was nearly
three times as much as it was in Germany. That simply excluded
the manufacture in England of a large number of materials in
which ether was required. The Excise authorities absolutely
refused to allow ether to be made from pure alcohol ; it had to
be made from industrial alcohol. That put a large extra cost on
the manufacture of ether from several points of view. Acetic
ether was another product which was debarred from being made
from pure alcohol, because the Revenue people considered it
would be possible to regenerate alcohol from the acetic ether !
Ether was the starting-point of the manufacture of quite a
number of fast yellow dyestuffs, which it was impossible to make
in this country owing to the fact he had just stated. But he did
not mean to say that the alcohol question was one of premier
importance. The question of the employment of chemists came
first. The British manufacturer must employ a larger number

THE SUPPLY OF CHEMICALS TO BRITAIN 333

of chemists, and he must reward those chemists sufficiently to
make it worth their while to do their utmost.

Mr A. CHASTON CHAPMAN said that there was a very large
body of British manufacturers who imagined that the office was
the central and most important part of their works, and that all
they had to do was, that if they paid their chemists (if they
employed scientific assistance at all) 100 per annum, to ensure
that at the end of the year there was 150 in their till. It
seemed to him that not only that section of the British manu-
facturers had to be educated, but also the British public, who in
such matters were exceedingly ignorant ; and it was through the
British public that pressure could be brought to bear on the
authorities where pressure was very badly needed.

Mr WALTER F. REID remarked that he did not grudge the
Germans the slightest bit of profit they made out of their own
inventions, but when an invention was made in this country and
it had to go abroad to be worked, there was something radically
wrong in the way the British inventor was treated. He could
give dozens of instances where inventors had produced good
ideas, but, owing to lack of help and opportunity, had had to let
their ideas die or sell them for a mere song. That was not a
healthy state of things. He might mention that he invented
smokeless powder. In the first place he had taken it to a
Government factory, and explained its properties. Some time
after an official waited upon him and said that all he claimed for
the powder had been proved, but that it could not be introduced
into the Army because, if it was, all the rifles would have to be
altered !

The Government should assist inventors. British manu-
facturers were in the position of an untrained mob going against
a drilled army. The commercial aspect of the matter was, in his
opinion, of the greatest importance, but the author in his paper
had put the business man last. He (the speaker) ventured to
suggest that some of the largest and best industries in the
country had been developed in the first instance by good men
of business.

Colonel CHARLES E. CASSAL (President of the Institution of
Chemical Technologists) said plenty of trained scientific chemists
were certainly necessary, but it was forgotten that in order to
produce the trained scientific chemist a long period of technical
education was necessary, which put a very severe tax upon the

334 THE BRITISH COAL-TAR INDUSTRY

father of the young chemist. After that, he had to be offered
something which was worth his while, and which would attract
the right sort of man. Many manufacturers in this country
had followed the objectionable practice of appointing Germans
as their chemists in preference to Englishmen, because the
former were " cheaper." He hoped that an end would be put
to this.

XXV.: 1914

BRITAIN AND GERMANY IN RELATION TO
THE CHEMICAL TRADE

BY WILLIAM R. ORMANDY, D.Sc., F.C.A.

(Journal of the Royal Society of Arts^ 4th December 1914, p. 46)

THE fact that Germany has slowly but surely been gaining
control of the greater part of the chemical industries of the
world has been brought home to this country times innumerable
during the last forty years. It is true that this control has not
extended to the manufacture of what are known as heavy
chemicals, where questions as to the cost of raw materials, fuel,
and freight are of deciding importance. The present unhappy
state of Europe, causing a shortage of many drugs and chemicals,
has brought this control home in an unmistakable way to the
public, who have been made to realise what the manufacturers
have known and ignored for at least a generation.

It is probable that the laws relating to the influence of en-
vironment, which have been proved to be so important in the
animal and vegetable world, will be equally applicable to the
development of industries, save that influences, such as national
temperament, education, and financial relations of a complex
nature, have to be brought into consideration. Industrial
development on a very large scale was first rendered possible
by the introduction of the steam-engine as a power generator
and the provision of adequate means of transport. At a period
during which this development was taking place here, the rest
of Europe was in a sufficiently unsettled state to permit of this
country, without serious opposition, becoming the workshop of
the world. No finesse was required to sell the output of our
mills and our ironworks. America, like a healthy growing child,

335

336 THE BRITISH COAL-TAR INDUSTRY

had an inconceivable appetite for all those finished and inter-
mediate products which could only be produced by a nation
whose industries had been slowly developed and well established.
In those days the English manufacturers, who paid low wages
and exacted long hours, made enormous profits. The experi-
menting which had to be done to develop the various industries
was of a rule-of-thumb character and essentially non-scientific
in its nature. Probably no nation is so well fitted as the Anglo-
Saxon race to develop rapidly along such lines. As a race our
people are practically inclined, and so long as development
required nothing more than the close application of a healthy
common sense, progress was astonishingly rapid. A very old
man, whose family was one of the earliest to take up the manu-
facture of cast steel in this country, has told me that in the
early days of the firm's history it was no uncommon thing to
receive orders for tons of steel required for the manufacture of
drills and tools to open up the virgin wealth of America, in
which not only was no price mentioned, but it was explicitly
stated that within the bounds of reason quick delivery would
compensate for any price. The products of our boiler yards
were famed throughout the world, and incredible profits were
made by firms whose successors have found the competition of
recent years more than they could support. This was, of course,
due to the fact that in the days of prosperity the profits were
divided to the last penny, the machinery was allowed to get out
of date, and the working people refused any longer to play the
part assigned to them by the manufacturer in his profit-making
schemes. Dr Mollwo Perkin has probably given the correct
explanation for this pronounced tendency of British manu-
facturers to starve and bleed their own business. The rapid
industrial development of foreign countries called for enormous
capital for railways, shipping, docks, and harbours, and the
opening up of mining and agricultural properties, and it was
felt that a better return could be obtained from such ventures.
English spinners and weavers were supplying the whole world
with their products, while loom and mule machinery makers
were working day and night to supply these foreign purchasers
with the machinery for their infant industries which were in future
years to compete with the home country for their own and
neutral markets. For close upon a hundred years the tide flowed
in our favour. There was no necessity to practise economy.

CHEMICAL TRADE IN BRITAIN AND GERMANY 337

Nature had been lavish with our raw materials, our insular
position and the proximity of our manufacturing centres to the
sea-board gave us natural advantages which, added to a favour-
able situation in international relations, rendered the growth of
our material success inevitable. To the thinking mind, it was
obvious that such a concatenation of favourable circumstances
could not continue indefinitely. We provided other countries,
at great profit to ourselves, with all the means necessary for
competing with us in these markets in which we had hitherto
enjoyed a practical monopoly. Our own works were frequently
equipped with out-of-date machinery, which was busily employed
in making more modern plant which was put into the hands of
those who realised that they would have to exert their powers
to the utmost if they were to gain a fair share in the barter of
the great international bazaar. The British industry of to-day
is in the position of a son inheriting an established business, and
having in addition a very large income derived from the labours
of past generations. Properly used, such a situation should
make for enhanced prosperity ; but even such powerful ad-
vantages may be nullified if the effort to work along the lines
which proved successful in our grandfathers' days be continued
too long. Capital directed by ignorance and apathy cannot hope
to compete for ever against the forces which are brought to bear
to-day.

The industrial life of Germany may be said to have com-
menced little more than a generation ago. To all intents and
purposes an inland country, with little sea-board, they were
under a huge disadvantage in every department which required
raw materials obtained from abroad. In many directions their
natural resources were comparatively poor. They had no iron
ores which were comparable with the hematites of Cumberland,
their limestone was largely dolomitic, their coals were for the
most part poor in quality, and lay often in distorted seams, more
like those of our Bristol coalfields than the comparatively easily
worked deposits in our northern area. It was recognised at an
early period in their industrial development that national progress
in a country situated as was their own could not be left entirely
to individualistic effort. Nationalisation of railways and canals
became an obvious necessity if differential traffic rates were to
be allowed, and differential rates were an absolute necessity if
large industries were to be developed in the interior of Germany

338 THE BRITISH COAL-TAR INDUSTRY

far from the sea-board. Too much credit cannot be given to
the far-sighted way in which every problem of agriculture and
industry in Germany is regarded from a national standpoint.
It is realised by everyone that individuality must be, to a' certain
extent, fettered for the benefit of the nation as a whole. In this
country individuality runs rampant, and except in times of stress,
such as those through which we are passing, the national or
Imperial bearing of any individualistic action receives not the
slightest consideration. The very people whose fathers sold
land to the railway companies at absurdly inflated prices now
complain that, owing to the high railway freights in this country,
they cannot make adequate profits from the investment of the
money obtained from those same companies by an earlier ex-
tortion. No doubt many of those who have made their profits
from such action would like to see the English railways
nationalised and freights reduced at the expense of that patient
beast of burden, the British public. Whereas Germany is con-
tinuously developing her network of waterways, we in this
country, with a customary lack of national forethought, allowed
our waterways to become controlled by the railway companies.

Having thus settled the enormously important question of
transport, Germany had to consider the lines along which she
should seek for an expression of her industrial destiny.
Agriculture, there as here the largest individual industry,
received attention which is as striking as is the lack of it in this
country. Proper afforestation schemes were rendered compulsory ;
enormous areas of land fit for little else were put under potato
cultivation, and science was called in to help to create a new
outlet for the crops. Germany became essentially the starch-,
glucose-, and alcohol-producing country of Europe. Other
large areas were used for the cultivation of the beet, and once
again science was called in to assist in the disposal of the roots
as raw materials for the production of sugar. If the manu-
facturing of iron had to become a great industry, it was necessary
to develop economic methods for the utilisation of the great
deposits of low-grade phosphatic iron ores which were those
chiefly available. In addition to the home deposits of iron ore
large amounts have been imported, but how successfully the
problem has been tackled is shown when we consider that
twenty years ago the German production of iron was a mere
fraction of our own, whereas to-day the German output exceeds

CHEMICAL TRADE IN BRITAIN AND GERMANY 339

the British by nearly 100 per cent. The problem of working
up the complex metallic ores has fallen almost entirely into
German hands. They alone were willing to spend the time
and money necessary on researches pertaining thereto, and they
alone seemed willing to devote that close chemical skill and
attention which is necessary in dealing with these complex
problems. In the early days of the chemical industry it must
have been quite evident that Germany could not hope to compete
in those branches of heavy chemicals such as soda ash, caustic
soda, sulphuric acid, bichromate of soda, alum, etc., where cheap
raw materials, freights, and cheap fuel play a greater r61e than
chemical skill and complex machinery. There is, however, not
the slightest doubt that Germany realised years ago what this
country has not yet grasped namely, that all industrial develop-
ment tends to become more and more scientific. The adequate
utilisation of the by-products from an industry may settle the
question of the survival of the industry itself.

The necessity for broad co-operation in great industrial
problems was recognised and acted upon in Germany in a
hundred directions. By-product recovery coke ovens were
installed in the immediate neighbourhood of the blast furnaces,
and the surplus gas from both was used for power generation.
The steelworks were erected in the immediate vicinity of the
blast furnaces, so that the surplus power might have an economic
outlet. Where it was impossible to bring the steelworks to the
vicinity of the coke ovens and the blast furnaces, the surplus
energy from these was transmitted far and wide in the form
of high-tension electric current sold at an astonishingly low
price and thus tempting to the introduction of new small
industries within the immediate area. The by-product recovery
coke ovens were required to another end. Slowly but surely
Germany had been developing her fine chemical industries,
drugs, and dyes. Many of these manufactures were dependent
for their raw materials on products only obtainable in quantity
from this country. We have been building up an enormous
industry, not only in the spinning and weaving of cotton and
woollen yarns and fabrics, but a correspondingly great industry
in the bleaching, dyeing, and finishing of these products. This
has been chiefly developed on dyes obtained from Germany,
but while we have been content to leave ourselves entirely in
the hands of others, the Germans have, by the exercise of

340 THE BRITISH COAL-TAR INDUSTRY

scientific skill and a sensible use of capital, rendered themselves
independent of this country. German capital was spent like
water to foster the development of by-product coke ovens and
in the development of the allied fireclay trade for the production
of suitable apparatus, to the end that fifteen years ago practically
the whole of the hard coke produced in that country was made
to give up its toll of by-products which were the raw materials
for their great chemical industry.

At a recent meeting of the Society of Chemical Industry,
Professor Henderson referred to the chemical industries of
Germany as being merely the development of the crumbs from
the British loaf with which they had had to content themselves.
In so far as the metallurgical industries are of necessity chemical
industries, the term " crumb," as applied to an iron and steel
trade much greater than our own, seems out of place, and the
remark is only another unfortunate example of the willingness
that exists in many quarters to pander to an already too strongly
developed feeling of national self-esteem. The British as a
nation never show up so favourably as when they are placed face
to face with difficulty. As a race we have so much of which we
can be genuinely proud that it is a little less than treason when
those to whom the people should look for guidance and warning
feed them with fulsome flattery and lull them to continued sleep
with mental opiates. In ever-increasing degree, both in this
country and Germany, the population are dependent on in-
dustries for their livelihood. Both countries have long passed
the stage at which their home market is capable of keeping the
industrial machine in full activity. In addition to each being the
other's largest customer, both have to look to the rest of the de-
veloped parts of the world for an additional outlet. Someone has
said that a nation gets the newspapers it deserves. Judging by
what has appeared in some portions of the daily Press during
recent months upon the subject of German trade, it is devoutly to
be hoped that the common sense of the British nation will not be
judged thereby. During the past ten years a nation of over sixty
millions has been increasingly occupied in industrial operations.
Our own smaller population has, on the whole, been equally
fully employed during the same period, and yet people write
as though there was a possibility that a large proportion of the
activities of the larger nation could be profitably undertaken in
the smaller country whose work-people have been for the most

CHEMICAL TRADE IN BRITAIN AND GERMANY 341

part well and profitably employed for the last decade. The
absurdity of this requires no refutation. Indignation is expressed
at the discovery that German people and German capital are by
way of controlling an ever-growing number of industries in this
country. I have not seen that any serious attempt has been
made to the much more serious end of discovering why the
Germans should desire or should be able to get such a foothold
in this country. In some few instances I could supply an
answer from my own experience. We have already seen how
the German Government brings science and agriculture to work
together in afforestation, and the cultivation and utilisation of
potatoes and beetroots, but throughout the German national
history the Government has recognised that, as a people, they
are in ever-growing degree forced to live on industry, and that
modern industry is built on the hand-in-hand co-operation of
science and capital. This country is dependent upon industrial
development for its very existence in a higher degree than
Germany, and yet so far as governmental assistance or interest
is concerned the principal occupation of the British people might
be the signing of dividend coupons. The German Government
is incomparably poorer than our own, and yet the financial
assistance which it renders to technical education is immeasur-
ably greater. The standard of general education is undoubtedly
higher, no doubt largely in consequence of the temptation
offered by their one-year service system in the army to those
who have passed a certain high standard of efficiency. In a
land where the standard of payments is, on the whole, much
lower than our own, the leading men of German technical schools
are far better paid than in this country. The heads of the
technical school staffs are encouraged to become acquainted with
the latest technical progress. It is fully realised that a purely
academic teacher cannot turn out first-class technical men. The
technical industries instantly claim, at higher salary, the members
of the staff of technical colleges who have carried out original
investigations which seem likely to open out industrial possi-
bilities, and it is not an uncommon thing for such a man to be
reclaimed by some technical institution at a later date at a still
higher salary. It is realised that the right man, who has works
experience as well as technical knowledge, is worth far more
to the nation as a teacher than in a private capacity. If an
industry requires to make use of ingredients such as alcohol and

342 THE BRITISH COAL-TAR INDUSTRY

ether, which are under excise control, the Government will go to
the greatest trouble to arrange matters in such wise that no needless
restraint is imposed. That the staff of a Government department
should interpret a Government order in an unduly restrictive
sense, so that an industry might thereby be hampered, is there
inconceivable. Only in Great Britain and Turkey are Govern-
ment restrictions allowed to be interpreted at the will of the
permanent officials. I do not for one moment wish to imply
that I consider that the question of industrial alcohol has been
of the main, or even of serious, import, compared with others,
in our neglect of the fine chemical industries. I quote it rather
as an example of the contemptuous attitude which our Govern-
ment has hitherto adopted towards matters industrial. In certain
branches of the chemical trade it is essential to have the
chemically pure alcohols and ethers, but the would-be manu-
facturer is told, by the Government, in effect, that he is not to
be a judge of what is necessary, but that the question will be
settled by some heaven-sent genius in their permanent employ
who, like the journalist on a halfpenny paper, knows more about
the subject than the man who has made it a life's-work.

A feature of the German industries is their willingness and
ability to work in co-operation, as is shown in many ways which
are no doubt familiar to most of you, but with which we have
not time to deal. With all the help which a favourably-inclined
government could render, the German industries would have
been unable to approach their present standard of efficiency had
it not been for the remarkable co-operation which takes place
between science and capital. This can perhaps be best illustrated
by means of some concrete examples. Let us suppose that some
chemist in Germany has discovered a new and cheaper method
for making some chemical product which is in considerable de-
mand, or which might become a large article of manufacture if
the price were sufficiently low. If the manufacture is likely to
require a considerable capital, the inventor would probably go to
one of the large banks. The German banks permanently retain
the services of some of the leading authorities on a wide range of
subjects, and the inventor would be asked to put all his case before
the particular expert in charge of his department. If the report
were of a sufficiently satisfactory nature on the scientific side, the
bank would proceed to make their own inquiries, through the
many channels open to them, as to the probable outlet for the

CHEMICAL TRADE IN BRITAIN AND GERMANY 343

new product. If the outlook were in all respects sufficiently
satisfactory, they would advance the necessary capital at a reason-
able rate of interest, making certain stipulations such as that the
business should be carried through their bank ; that payment for
the finished products should be made through the bank ; that no
contract for the sale of the finished product should be made with
any firm without their consent. The bank having much greater
facilities for gauging the financial standing of the purchasing
public, in this wise protect their own interests and that of the
inventor.

Again, nothing is more startling to the Englishman than the
ease with which one can gain admission to those in command of
the great industries. The directors of the German companies,
for the most part, and the managing director invariably, are men
of high technical skill in the business they control. The idea of
putting a stockbroker or a retired army colonel at the head of a
scientific industrial concern would be regarded as an act of mad-
ness. Not only are German businesses run by men who under-
stand them, but these industrial leaders have always time to give
adequate consideration to any new proposal which is brought
before them. It would be the exception rather than the rule to
find directors in an English company who were capable of ap-
preciating, still less of judging, the merit of a technical point
relating to their own business. It would be almost an impossi-
bility for an unknown outsider to obtain admission to such
directors, and even if the unknown inventor succeeded in getting
within the veil which hides the holy of holies, it would probably
be to find that the master-mind had so many appointments that
he never by any chance had time enough to consider any proposal
thoroughly. The heads of a German concern have always time
to look thoroughly into anything which interests them ; they are
sufficiently technical to realise the necessity for going into details,
a works experience having taught them that it is on details that
great processes come to grief. In spite of their intellectual and
commercial attainments, however, these directors are, in some
respects, both modest and unassuming. They still think that
success can be purchased only at the cost of labour ; they are
content to work from 8.30 to 6.30, with two hours' pause in the
middle of the day, and they work full six days to the week. No
doubt they envy, but they do not lay claim to, that super-type of
intellect which, labouring hard from eleven till four with an in-

344 THE BRITISH COAL-TAR INDUSTRY

terval for rest, sometimes even five days a week, expects, not only
to retain its old position, but to dispossess its competitors ; they
even learn foreign languages so that they may profit by the
knowledge gained by other people in other countries.

Let us suppose for one moment that it was Germany that
was short of drugs, photographic chemicals and dyes, and that
England had possessed a monopoly in these products. Further,
we will suppose that the joint general manager and head chemist
of one of the large English drug and photographic chemical
works had found himself in Germany at this period, with
sufficient acquaintances in that country, men with whom he
had for many years made large contracts and who were fully
cognisant of his scientific and technical ability to guarantee his
claims. He could go to any bank and say : " I can show you
how to make a number of photographic chemicals and drugs
even more cheaply than they can be made in the country which
has hitherto controlled the manufacture, because you have the
necessary raw materials, because you have, indeed, previously
sold these raw materials to the previous makers. I bring you
the necessary evidence that these products can be made at half
the sales price obtaining before the war, and I can demonstrate
that the sale in your own and neutral countries of these products
amounts to some thousands of tons per annum, and that, under
normal circumstances, after the war is over, it will be impossible
for your business to be displaced by undercutting. Finally, I
will bring you reputable dealers who will make contracts for
hundreds of tons of these products at prices which will pay for
the plant and show profits in one year's working." The bank
would confirm these statements through their experts, and probably
within forty-eight hours all the money that was required would
be available at yj per cent. The man who possessed the scientific,
technical, and commercial knowledge would thus be enabled to
build up a business which would be profitable to himself and
valuable to the community, the fact being that it is recog-
nised in Germany that capital is entitled to a fair return and
nothing more.

Now let us imagine that circumstances were reversed. It
would require the pencil of a Hassall adequately to depict the
scene in the board-room of an English bank where such a
proposal had been made. One can imagine the possessor of
such knowledge offering it to existing chemical works.

CHEMICAL TRADE IN BRITAIN AND GERMANY 345

Modern commerce is warfare, and the weapons employed are
inventions, tireless industry, skill, and capital. We make the
mistake of putting the last first. Those who do research and
make inventions, whether in chemistry, engineering, or any other
branch, are the yeast which leaven the whole mass, but in this
country we do not allow those conditions of warmth which permit
the yeast to work. Gold in itself is not nearly so valuable a
metal as iron, and we are slowly but surely finding out that
capital itself is an over-valued possession if it be not used for
the benefit of the industries and consequently of the nation as
a whole.

DISCUSSION

The Right Hon. Lord-Justice MOULTON said that he had
had allotted to him for several weeks past the business of in-
vestigating into the question of the supplies of articles which in
peace time were imported from Germany. First and foremost
of those had been the problem of the great chemical trades,
especially the great industry in synthetic dyes, and he had had
an opportunity of marking in detail those things in which England
had allowed herself to be supplied in chemicals from Germany.
He could assure the audience that he had noted the fact with
great sadness, and, he was bound to say, it was a great national
humiliation. The fact was that chemistry opened up, especially
some fifty years ago, a domain of industrial wealth which he
could only compare to the domain which was opened up when
steam power was first invented ; and to his great sorrow he
could come to no conclusion but one, and that was, that either
from being too well off, or from sluggishness of intellect, or from
the fact that the capital of the country had passed into the hands
of people who were unwilling either to learn or to think, England
had abstained almost entirely from attempting to reap the rich
harvest that was opened to the industrial world by the advances
in organic chemistry. The fact was too well marked for us to
pass it by as being a mere incident in national life. Of course,
no one thought that every nation could do everything ; and that
nations should, to a certain extent, specialise, should take ad-
vantage of their natural position, and the deposits that they
found in their land, their climate, and things of that kind, was
not only normal but desirable. But thought depended on no
climate. Thought was open to us all ; and the fact that England

346 THE BRITISH COAL-TAR INDUSTRY

neglected the chemical industries could not be explained away
by any suggestion that it was either incapable or for any natural
reason unfitted for their pursuit. One had to look deeper than
that. One had to find some fault either in the national character
or in the national behaviour which would account for it ; and he
did not believe that England could, after the war, survive as a
great industrial nation if she did not correct that fault, if she
did not make an effort to take her place and that an uppermost
place in the world of industry in chemical matters as well as
in all others. If the conclusion was come to that it had been
by a national fault that we had missed it in the past, and that
we were not going to live a disgraced life in future, it meant
that that fault must be found out for the purpose of avoiding
it, and there, he thought, a lesson might be taken from our
enemies. To his mind by far the most glorious moment in
the history of Prussia was not the moments of her military
successes it was the moment of her deepest disaster. Those
who knew Prussian history would remember that after the
nation had been prostrated by Napoleon in the Battle of Jena
the national independence was utterly taken away. The restric-
tions the conqueror put upon them were humiliating in every
way. At that time there arose a set of men, of whom he chose
to name, first, Fichte, who told the Prussian people in the
clearest language that their disaster was due to their national
faults, and pointed out the way that they must correct these ; and
in the most unsparing language he told them that it was only by
self-discipline, only by taking to heart their disaster, seeing in it
the natural consequence of their national faults, that they could
possibly get the resolution or the strength to replace their nation
in the position which it ought to occupy. The whole nation
listened. It was at that time that the Germans took to physical
development and voluntary drilling. They prepared themselves
in every possible way for that coming fight which they hoped
they would have with their oppressors, and which they had in
the course of a very few years, but they did it under the exhorta-
tions of these men, because they did not attempt to hide from
themselves that it was the nation that was to blame for its
misfortunes.

The fact that our chemical industries were in such a backward
state, with certain exceptions of those which needed least thought
and least study and least knowledge, was grave enough, if, as

CHEMICAL TRADE IN BRITAIN AND GERMANY 347

he said, it was due to our national faults it was grave enough
for us in these days to rouse ourselves as the Prussians did rather
more than one hundred years ago. He was quite sure that if
we did do it the same result would come that we should regain
our position, and regain it with even more glory than it possessed
before. There was a time when in no industry could England
look on other nations as its superior. Now, in the chemical
industry by which he meant mainly the organic chemical industry
it was all but insignificant, and he read with very bitter feelings
an address of one of the ablest industrial chemists in the world,
the head of the German chemical industry, who was talking about
the very subject, and who said : " England talks now of not only
holding her own in war, but beating us in our chemical industries.
She cannot do it, and that is because the nation is incapable of
the moral effort to take up an industry like that which implies
study, which implies concentration, which implies patience, which
implies fixing one's eye on the distant consequences and not
considering merely the momentary profit." When he read those
words he asked himself, Was that not a fair judgment for a
foreigner who could not know the resources of the English
people in the way of repentance and resolution and reformation ?
Was it not fair for that gentleman to say that our behaviour
during all these years showed that we were incapable of doing
it ? And he would tell them frankly, that if we did not take the
lesson to heart at the time of this war, and when the war had
passed when, as we believed, we should have severed ourselves
from the military domination of Germany resolve to save our-
selves from industrial domination, all he could say was that the
victory of Germany, if not in the form that it would desire,
would be quite as great as it could wish.

Sir WILLIAM A. TILDEN said he had listened with mixed feel-
ings not only to the paper but to Lord Moulton's remarks. He
could not help hoping most sincerely that the words which had
been used by Lord Moulton would find an echo in those regions
inhabited by the leaders of British industry ; for it appeared to
him that unless a good many of them first of all were brought
to acknowledge their position of humiliation, and secondly, de-
termined that if they were too old themselves to learn, at any
rate their sons and successors should be taught what was neces-
sary in the way of scientific instruction connected with their own
businesses, then it was all over with British industry. He must

348 THE BRITISH COAL-TAR INDUSTRY

say out of his own experience, living as he had for fourteen years
in a great industrial centre, that many of the author's pungent
remarks were really not exaggerated. He used to see, with great
regret, young men driving to business in the morning at eleven
o'clock when the works had been going from six o'clock. In
many works which he had visited he invariably was amazed at the
extraordinary ignorance displayed on the part of the partners them-
selves in the operations which they were supposed to conduct in
their businesses. Over and over again he had been in works in
the Black Country, and his friend, the director or manager, was
exceedingly anxious to show him anything ; but if he asked any
question about details the manager or director could not answer
them, but sent down the yard for " Old Tom " or " Old George,"
who was the only person in the place who seemed to know how
the process could be conducted. He did not believe that the
serious character of the question of education had yet been com-
pletely realised by the present industrial directors and leaders,
and he could not help thinking that that was one of the most
important considerations to be taken into account at the present
time that the young men who were to be the manufacturers of
the future should have a very different kind of career from that
which had been hitherto prevalent.

Dr M. O. FORSTER said, whilst fully agreeing with the author
in his castigations of the manufacturer and the Government,
yet he did think that while chemists were so busy in casting
motes from other people's eyes, there was one beam in their own
which certainly should be removed forthwith, and he thought
the present opportunity was the right occasion to remove it.
They had too long allowed confusion in the public mind as
to what really chemistry was, and what chemists did. It was
perfectly ridiculous that any attempt whatever should be made
to capture German trade while the general public had not the
faintest idea of the difference between the chemist and the drug-
gist. At the present time the only people who were entitled to
call themselves chemists were those who had undergone a course
of training at the Pharmaceutical Society or who had passed ex-
aminations conducted by that body. In fact, he believed, of all
the chemists, so-called, present that evening, only Sir William
Tilden was entitled to call himself a chemist by law. In Germany
and France chemists and druggists were clearly defined.

Dr RUDOLPH MESSEL thought that we as a nation had

CHEMICAL TRADE IN BRITAIN AND GERMANY 349

been blind, so far as new chemical industries were concerned.
We had everything ready at our hand. At one time there was
a great deal of grumbling about education in science. He had
been in England for forty-five years, and he could well speak
about the enormous progress which had been made in this
country as far as chemistry was concerned. There was talent
enough, capital enough, raw material everything. But what
was lacking was enterprise. If the talent which was now avail-
able in this country was utilised, the industry would do just as
well here as in Germany. He had to give one word of warning
in establishing new industries first of all to be sure that we only
took up those industries which we were prepared to defend when
war was over.

Dr F. G. OGILVIE said that the deplorable condition to
which the author had drawn attention was not at all peculiar to
the chemical industry ; it has been observable in a great many
other industries. There had been a tendency in connection with
many individual industries for the divorce of the control of capital
from the knowledge and experience required to apply capital
effectively. It arose in the following way a man had done very
well, say, in the manufacture of tweeds in a centre where a large
tweed industry was going on. His family found themselves
very well to do, and were attracted, as young men, much more
to field sports, county meetings, and things of that sort than they
were to the serious study of their own particular business. The
net result was, when they came into power they had to work the
business by managers, often underpaid and undertrained, who
naturally, even when they proved themselves very good men,
had not the ready access to the application of capital year in and
year out which was necessary to keep the business up to date.
This did not happen where the sons had added scientific training
to practical experience in the works. In that case there were
good, solid, steady-going businesses which were introducing new
products just as fast as could be wished.

Mr ADAIR ROBERTS said that many of the businesses which
it was now sought to capture from Germany could be started
with very little capital.

Mr WALTER F. REID said he thought it was quite impossible
to suggest that a young chemist, just out of a college or uni-
versity, could get a large salary unless he showed himself to be
worth it. An employer would look at him as a beginner from

350 THE BRITISH COAL-TAR INDUSTRY

the industrial point of view. In fact, he was an apprentice, and
if he was not willing to take the salary of an apprentice at the
beginning he could not grumble at the capitalist, who opened up
to him a very good future of great promise. With regard to the
glass industry, we had lost that industry chiefly through the
unwillingness of the workers in the trade to allow apprentices in
sufficient number. After the production of capital, the next
important point was the security of it. He could not put the
matter more clearly than it was put by the Institute of Chemistry,
which said, " Provided that the manufacturers could be afforded
some guarantee of permanency for their enterprise, and that they
may have some reasonable assurance that at the conclusion of the
war the newly developed industry will not suffer from foreign
competition, hitherto made possible by economic conditions
which do not prevail in this country." Dr Messel had said
exactly the same thing. If the capital which would have to be
invested in new and expensive plant and in the payment of re-
search workers and other workers could not be secured, then the
capitalist could not be blamed for not coming forward. Our
workmen and capitalists must be given the same protection as
Germany gave to theirs. Our German competitors could then
be met on equal terms, and he was not afraid in the least what
Englishmen would then do.

The Lecturer said he agreed absolutely with Dr Messel that
we must be most careful to take up only those industries where
we were at least on as good a footing as the Germans were with
regard to raw material. With reference to workmen, he had not
the slightest doubt that English workmen were better than any
other workmen on the face of the earth. But up to the present
neither the English workman nor the English chemist had been
given half a chance to handle modern scientific processes. It
was the opportunity to let each of them prove what he could
do that had been lacking.

Mr W. H. MAW said that the state of affairs which the author
had described as existing in the chemical industry also existed in
past times in many other industries. In the case of the engineer-
ing trades and iron and steel manufactures the last twenty years
had seen a very remarkable advance in the recognition of the
value of scientific research, and he hoped the same advance would
take place in the chemical industry.

XXVI. :

THE MANUFACTURE OF ANILINE DYES
IN ENGLAND

BY THE RIGHT HON. LORD-JUSTICE MOULTON,
P. C., K.C., F.R.S.

(Address delivered in the Town Hall, Manchester, on 8th Dec. 1914)

SOME weeks ago now I was asked by Government to take the
Chairmanship of a small Committee that had to investigate the
straits into which England was put by being cut off from that
great supplying nation, Germany. I have had to investigate all
the unsatisfied wants that have sprung from this war, and I am
glad to say that in almost all the cases which cropped up so
numerously at first it has been found that the resources of
English enterprise were sufficient to meet the demand ; that
some makers have been more attentive to the variety of the
tastes of their customers ; that others have increased their works ;
that others have added new branches to their business ; and that
the straits have been alleviated if not removed. Everything that
has happened has placed in harsh and dissonant contrast the
question of dyes. Nothing that I have seen during these weeks
and I can claim to have spent almost every hour of the day in
meeting the members of the trades affected, and in trying my best
to find some way out of the difficulties nothing that I have seen
in these long weeks has weakened, nay, I can say nothing has
failed to strengthen, my feeling of the gravity of this problem.

The consequence is that after long reflection I have come
to certain conclusions, and I have not hesitated to place them
in the clearest language before the Government. Now the
Government has taken an unusual and almost unprecedented
step in the direction to which I refer. I am not responsible for

352 THE BRITISH COAL-TAR INDUSTRY

the details of that step. I am not in any way connected with the
shape or form in which the action is to take place otherwise than
so far as it has been a necessary consequence of the advice that
I have given. The one thing I am responsible for is that advice,
and I stand here not as the representative of the Government,
not as an advocate of a particular scheme, but to give you the
same advice, based upon the same considerations, the result of
the same reflections. Although that is a strange position for a
man who is speaking in public, it is no strange position for me.
There are the faces of many here in the audience who in years
past have come to me for advice ; who have asked it and taken
it ; who have shown by their coming that they had faith in my
judgment. Well, I hope that faith has not entirely passed away.

But in any case I am coming in the attitude of one who
is giving advice. When I used to see them in my rooms at the
Temple I would as soon have thought of chanting my opinion
as trying to put it in eloquent words. It will be the same to-
day. I shall put to you in plain business language the things
that have haunted me for these weeks past ; things that have
oppressed my thoughts day and night. In my opinion we are
at a crisis of our national life, and I shall try to put as plainly
as possible, in the simplest words, the facts which have led me
to that conclusion.

When I began to investigate the lack of dyes I found Eng-
land consuming some two million pounds* worth of dyes per
annum. They were essential to an industry of something like
two hundred million pounds per annum, and on which at least
a million and a half workmen were dependent. And I found
that of the two million pounds' worth of dyes that was required
year by year barely one-tenth was produced within our own
boundaries. I looked round for industries which could at a
pinch supply the deficiency. So clearly demarked from other
industries is the great chemical industry of the coal-tar dyes that
1 could find no industry which could take its place.

I found that the stocks of dyes, the stocks kept in peace
times for no warning of the intended war had been vouchsafed
to English customers I found that those stocks were rapidly
diminishing, and that practically there was only one nation from
whom we could expect help. I refer to Switzerland, and I knew
that in that country pressure was being put by Germany of the
most intense kind threatening to stop all those supplies of their

MANUFACTURE OF DYES IN ENGLAND 353

intermediate products on which the Swiss dyemakers had built
up their business, unless they would promise that not a pound
of their dye should, for the whole period of the war, come into
this country. I found certainly some English firms who were
manufacturing, and manufacturing successfully, in spite of the
competition of the Germans. But what they could supply was
indeed inadequate to keep going the great textile industries
which ultimately depend to such a large extent upon the dyeing
industry.

That was the serious immediate prospect. But what does
the future promise ? It is that which I have been brooding upon
ever since. Supposing that this war was finished. Supposing
that by the bravery of our soldiers, and by the unflinching
determination of our Government and that of the Governments
of the Allies, we come out of it politically free. What position
do we step into industrially ? We step into the slavery of the
Germans, so far as our textile and dyeing industries are concerned,
as absolute as they hoped to put us in a political and military
sense.

What I am saying is no exaggeration. In my perpetual
converse with those of you who are practically interested in the
question I have learned the German methods of carrying on
business. I know their way of dividing all the nations up into
watertight compartments, by their system of selling dyes not to
be exported, so that they can put the price up to one nation and
down to another. I know the way in which even the two great
rings, which may be competitors one to the other in Germany,
are united against the foreigner.

I say gravely, meaning every word that I say, that if peace
were declared at this moment you in the English textile industry
would be so much under the domination of the German dye-
producing industry that it could boycott you in the way of dyes,
it could overcharge you for dyes, and it could hamper that
industry pending the time when it had the capital and works to
challenge its very existence. And as an Englishman, that fills
me, I will not say with dismay because I have a blind faith in
my countrymen which makes me believe that out of the most
difficult position they will, when they once realise it, pull them-
selves successfully but it made me feel that it was my business
to sound a note of warning, and not let people go on thinking
that this trouble from shortage of dyes was one which would be

354 THE BRITISH COAL-TAR INDUSTRY

temporary, lasting only during the war time. No. It was a
signal of danger which threatened us more in peace than in war,
and if we would not listen to this danger signal then our fate
was on our own heads.

Well, now, in most things you ought to consider how to do
them before you determine to do them. But there are ex-
ceptions. This war was an exception. I do not think that
many of us knew how we were going to struggle through this
war, but yet I doubt if there is a man in this audience who did
not feel that we must take it up. I feel about this industrial
war just the same. I feel that the first thing we have got to do
is to ,say to ourselves, " That shall not go on." And then we
have to set to work to find out how we can stop it.

But to find out how we can stop it we must first consider
what are the causes which have led to this strange position, that
a great enterprising industrial nation a nation which lives upon
export industries is in the largest of its export industries, which
I believe produces one-third of the total exports, at the mercy of
the foreigner. How was it that when the great chemical trade,
based on the marvellous way in which coal-tar products will
assume myriad forms and myriad different properties, when that
El Dorado was discovered, far more valuable than the Rand ever
will be, how was it that England did not have its share ?

Was it discovered by foreigners ? It was started by an
Englishman. Was it that foreigners alone had the natural
resources to carry it on ? For years practically all the raw
materials wanted for this industry were sent out in an untreated
state from England. Then why was it ?

Gentlemen, we have got to look the truth in the face. It
was for no other reason than the English dislike of study. The
Englishman is excellent in making the best of the means at his
disposal, but he is almost hopeless in one thing. He will not
prepare himself by intellectual work for the task that he has to
do. Now in the last fifty years the knowledge of the world,
the additions to that which we know, which have been piled up
from the work of ten thousand independent investigators, each
applying himself to one thing, have made it so that with regard
to each subject there is a vast amount of the " known." And a
wise man who means to deal with a subject will master what is
known before he attempts the problem of what he can do. That
is what the Germans, who were rightly ambitious, accepted as

MANUFACTURE OF DYES IN ENGLAND 355

the condition of success in industry. If you talk to any German
who is engaged in any industry you will find that he knows
about it all that can be known.

I admit that it does not make him a more pleasant com-
panion. Once I found myself on the top of one of the Dolomite
Mountains, and the only other person there besides the guides
was a German. I found out that he was a chemist, and I began
to talk upon a chemical subject. He told me he was only an
organic chemist. He had not exhausted my resources, and I
began to talk of coal tar and pharmaceutical products. Then he
told me that he was a coal-tar by-product chemist. That did not
beat me, because I had just been righting a case of canary yellow.
I thought I would get some subject which was common to us,
and I slipped into the subject of canary yellow. Still the same
ominous silence for a time, and then he said, " I am only a coal-
tar chemist dealing with blues." But I had not finished. With
an Englishman's pertinacity, not believing I was beaten, I racked
my brains for a coal-tar blue I had had to advise on some cases
and I gradually, without a too obvious change of subject,
slipped into that. Then he finally defeated me, because he said
in equally solemn tones, but equally proud of the fact, " I only
deal with methyl blues."

That gives you an idea of the way that a German is willing
to give up everything so as to concentrate on the subject with
which he has to deal. It may limit his general view of life. I
confess that it is almost worse than wearing blinkers. Goggles
are the only thing I can think of which at all describe the mental
limitations. But this makes the Germans most formidable in
industrial questions. It makes them thorough in that which
they have to do.

Now, apart from certain business methods which I may have
to refer to later on, I believe the sole cause of England's falling
back, and Germany's possession of this great industry, is the
fact that the Germans are perfectly prepared to undertake the
intellectual study necessary to master the new science. The
English, I believe, could do it just as well, and you will find in
their great works English chemists as highly respected as the
German, and as efficient. But unfortunately the holders of
capital in England have had little sympathy with knowledge that
they did not themselves possess. As I have been talking these
matters over with people energetic, good, industrial producers

356 THE BRITISH COAL-TAR INDUSTRY

I have always found that when I commenced to talk about the
intellectual study necessary to deal with chemical science there
has always been that tone recalling the voice of the sluggard,
" You waked me too soon."

They know the time is coming when they will have to do it,
but they hope that during their time the traditional ways of their
fathers may be sufficient, and let the next generation face the
intellectual difficulty of study. The consequence has been that
inventions great inventions have fallen dead in England.
They have been offered in Germany ; they have been studied by
instructed minds ; they have been accepted. And the con-
sequence has been great industrial production, the fruit of which
all the rest of the world has received. But in England, " Well,
ah ! yes. It has not been tried. It is difficult/' It is given to
somebody who has not disciplined himself like the Germans do,
and he finds difficulties, and then gradually the thing is dropped.
For you must remember that because the masters, the heads, the
capitalists, have not got sympathy with this self-preparation for
the difficult tasks, there is no career for the young men who are
willing to study. What can they do ? They are paid salaries
quite insufficient for the training they have to go through, and
for the learning they have acquired. The consequence is, that
when I am asked how it is that we are so poorly represented in
the industrial ranks by chemists, I say, " Make a career for your
young chemists, and then you will see." We have not done so.

Now that is the cause, and, so far as is material, the sole
cause, of the German supremacy. Remember that there is not
one single thing in which we are at a disadvantage by natural
position. It is perfectly true that in the Creation, by some
blunder, the most valuable deposit of potash was put in the
centre of Germany, but we can get potash from elsewhere if we
want it. As to coal, and the sources of the coal-tar industry, we
have them in richer quantity than even Germany itself. The
one thing is the difference in the human element, and this
is not a difference in intellectual capacity, but in the industry and
in the willingness to study to the bottom the subject with which
you have to deal.

Gentlemen, that is my opinion of the cause of England's
inferiority, and I ask myself at once, " Is that a cause which must
permanently operate ? " The answer is, of course, * c No." But
it is for us to reform ourselves. Otherwise no relief can come.

MANUFACTURE OF DYES IN ENGLAND 357

It is impossible that we can get a chemical industry like the
German's unless we are willing to train ourselves for it, to have
faith in it, to embark our capital in it, and in this way take the
steps which lead to it. Consequences follow causes in this
world ; and to hear people grumble at this difficulty about the
dyes when one thinks they have neglected all the necessary
causes to produce the industry, would make me feel almost
impatient if it did not make me sorrowful.

The question is, then, has the condition of things become so
permanent that it is too late to do anything ? Here I confess
that I feel cheerful. Let me deal for a moment with the
difficulties that appear to one. The first is that there is a lack of
the necessary technical skill. I have a great difficulty in returning
a polite answer to that. To my mind it is nonsensical. We
have the command, and we shall in peace still more have the
command, of abundant technical skill to create the industry. You
must remember this, that in the long catalogue of dyes (over
which I have been poring all these weeks) the vast number are
dyes the processes for the manufacture of which are well known.
I do not say that the man who is practised in it will not get a
better yield, or that his handiwork will not be more certain. Of
course it will. But there are no people better qualified to learn
by experience than the English people themselves, and the whole
of these dyes can be manufactured with as great certainty in
England if we put up the proper plant and choose the proper
men to guide it.

Now let me go to the more recent dyes, those that have
hardly made their way into commerce, but the qualities of
which show that they will be very desirable. It is perfectly
true that if you want to manufacture these on an industrial
scale you will previously have to study in the laboratory, by
observation of the reactions, how to get the best results. But
you will be astonished how few the processes are in this great
industry, and the extent to which they are simply the repetition
of the same processes with different substances and under
different conditions. The sole difficulty which separates brilliant
success from comparative failure is that study has shown how
to regulate the conditions so as to make the results most
favourable.

There is no mystery to the chemist. There is that which
requires study before he can arrive at it ; but if you are going

358 THE BRITISH COAL-TAR INDUSTRY

to be daunted by that, then the rest of my speech will not
interest you. So that the objection of not having abundant
technical skill to carry out any industry that we form is in my
opinion absolutely baseless.

Well, then I am told, " It is impossible to compete.
There are works with a capital of a hundred millions in Germany.
Your foes are willing to crush you by every means they know,
and those means, I can assure you, are various and effective."

Well, that is a very great fact, but if you tell me that it is
impossible for manufacture to go on in spite of this competition
1 will ask you to turn your eyes not only to this country, but
even to Germany, where you find firms outside these great
combinations, who in their own particular line have a successful
business, and even an export business, in which they contrive to
flourish not to make the gigantic profits of the rings, but still
to make fair industrial profits. In your own country you have
them. You have firms that in spite of the pressure of the
Germans manufacture at a profit. And side by side if you
look back with these firms there were many other firms whom
the Germans feared sufficiently either to buy out or to crush
out. When they realised that they were capable of producing
in competition with them they felt that at great cost they must
get rid of them. That, surely, is proof that competition in pro-
duction is not impossible.

Remember this, that success in production depends no
doubt on cheapness, but if you produce on what I may call an
economical unit, that is on a scale which is adequately great,
the advantages from doing it on an enormous scale are very
small in comparison. And certainly England, with its rich
market, its demand for dyes and many of these demands
capable of being satisfied with comparatively few dyes, England
can certainly start an industry in which the manufacture is on
such a large scale that it can challenge if not equal the economies
of the biggest works.

Let me now go to the third objection which is raised to the
possibility of our competing, and it is raised in connection with
the suggestion that I am defending here the consequence of
my conclusion that a great national effort should be made, and
a large company formed capable of producing dyes on a scale
sufficient to satisfy the English demand. It is a very curious
one, and yet you have all heard it. I remember saying to one

MANUFACTURE OF DYES IN ENGLAND 359

with whom I was discussing the matter, and who knew well
the trades of Lancashire and Yorkshire "Don't you think
it would be of infinite value to England to have a company
which would for ever secure its dyeing and textile .industries,
aye, and the great pigment industries, which must not be for-
gotten, from being overcharged for their dyes ? " The man
said, " But that is not what I am thinking about. I am not
thinking about being overcharged. My fear is we shall be
undercharged ! "

Here I was trying to protect an English industry. I was
talking to a man vitally interested in it, and what was his fear ?
His fear was that the consequence of our doing it would be that
you would get dyes cheaper than they could be made, and that
was what was frightening him. I will tell you what it reminded
me of. Supposing there was a question of building a defensive
fort to protect the vital part of a country, to protect, we will
say, London, and the objection was raised, " Oh, but if you
build it as strong as that nobody will attack it, and then how
will you defend the spending of your money ? "

I ask you to think of this objection seriously, and in the
light in which I am putting it to you. To my mind it is the
most universal and the meanest of all the things which influence
men's minds on this subject. They are afraid it will be too
successful. They know that if they do not make such a
company they will be ruthlessly overcharged by the Germans.
Of that there is not a fraction of doubt. They know that if
they do form this company that cannot be so, and the probability,
they think, is that your great industries will have their dyes
cheaper even than they can be made. They must realise that
that, to a nation which has a world-wide commerce, is a boon
beyond estimation, and yet they are afraid, if they put their
money in, that they will win this boon for their fellow-
countrymen.

What does it mean ? It is that ineradicable defect of the
English mind, if it has not by travel or study or reading got
rid of its insularity. I used to sit for a constituency, an
agricultural one in the South, and I never could get out of the
head of any one farmer that his real competitor was the man
living next door to him. He did not realise that this insular
idea of being afraid that the man next door will get the better
of you for a penny, or that his goods, which are not quite as

360 THE BRITISH COAL-TAR INDUSTRY

good as yours, will still be treated alike with yours, is the thing
which has prevented all co-operation among them in the south.
While Denmark, a poor country, has been rolling up its wealth
by combined action, our English people stand apart, and are still
as unfitted for helping the wholesale trade of the world as if it
were almost fifty years ago.

What this objection means is, you are afraid that Mr So-
and-So, who has not subscribed, will get all the benefit you have
won by your subscription. You do not doubt that you will win
it for your country. You do not doubt that you will win it
for yourselves. You do not doubt that in this way, so far from
industries being harried, they will be put in an undeservedly
fortunate position. And yet you do not want to do it because
the gain will come to your trousers pocket instead of to your
waistcoat pocket. Instead of coming in dividend it will come
in the lower price of dyes.

So, if I could believe that the formation of this company
would force the Germans for one year or two years or twenty
years to sell their dyes at less than cost price, I should come to
you and say, " You have got a chance now to save yourselves
and England, and to put yourselves and England in a position
of vantage in competition in foreign lands that you have not
deserved but that you are going to get."

But, gentlemen, I frankly tell you that I do not think you
are going to have such a good time as that. 1 will tell you why.
If a great company is formed that is efficient and that produces,
as an efficient English company will produce, at fair prices, it
will cost the Germans too much to sell below cost price here.
For this reason : once satisfy the English market with these low-
priced dyes, and you free the output of this company to go to
those Eastern markets, out of which the Germans derive the
profits which enable them to fight you, and you can sell there
at fair prices, and the Germans will either lose the market or
there, too, they must drop their prices.

I think you will find that dropping prices all round is not a
good way of increasing your profits. You are business men. I
am not a business man, but my opinion is that they will find
that it is better to leave you alone, better to leave you to supply
yourselves than to set free such a formidable output as a great
company would make to compete with them in the other markets
of the world.

MANUFACTURE OF DYES IN ENGLAND 361

What does all this lead to ? It leads to this. In my opinion
there must be, in order to give England industrial freedom in
this group, which is almost, I should think, or quite, the
greatest group of its industries there must be a great national
effort to create a company, a company working under the con-
ditions of other companies, suffering from its blunders and
profiting by its wisdom.

But there are three conditions, and unless those three con-
ditions are all satisfied it will be a failure.

The first condition I lay down is that it must be large.
Politically, the Germans are frankly the foes of small nations.
They consider that small nations are to be eaten up. Industrially,
this great embodiment of the German idea, the combination of
the dye manufacturers, behaves to small manufacturers exactly
as Germany seeks to behave to small nations. It is hopeless to
suppose that if there are sporadic attempts, all small, they will
not be either dragged into a combine, or crushed by a combine,
or in one of the many other ways, which you all know, put out
of existence. It must be large, and therefore independent, and
therefore beyond attack.

There is another thing. It must be national in this sense :
it must be removed for ever from the temptation of listening
itself to the voice of the charmer and entering into a combine.

We must have a company that is not only powerful, but one
the loyalty of which is necessarily beyond all doubt, and that we
can only get if it is assisted by the Government, on the terms
that the Government can stop it from ever entering into the
backward path which would ruin its national utility. Most of
you like the idea, I can see, of its being large, and of its being
kept always true and faithful to its national aim.

Now I am going to tell you the third condition, which
concerns you. It must be co-operative. The producer must
be the consumer. You will never link up all these industries
unless those who use the dyes are included, the textile people
as well as the dyeing people, and those who are in the great
pigment trade. Unless all those who are about to consume
have an interest in the production, and therefore supply a pre-
ferential market, you will never succeed in making the com-
pany relieve the national need. If 1 had had the millions I
wanted offered me on the Stock Exchange for a company which
would be free from all trammels, which would have no connection

362 THE BRITISH COAL-TAR INDUSTRY

with the trade, the shares of which would be bought as the others
that are called industrials on the Stock Exchange, where every
penny of profit it made would be squeezed out of it for the
benefit of the then holders of the shares, who would care nothing
for the holders of the next year or for the future of the company,
I would have said at once, " It is doomed to failure," and its
failure would be only the more marked because it was gigantic.

You must realise that you, the consumers, should loyally all
combine with the producing company, and then I will defy the
German or any other competition to break down that bond of
union. Remember this. The only thing which will ensure a
combine or a ring against failure is co-operation between the
producer and the consumer. I remember one of the earliest
cases that came before me. It was a case of a very great in-
dustry, and we were told that it was entirely in the hands of
such a ring formed in such a city in Germany. Well, what
happened ? We got the producers and the consumers together
and said, " If you will produce the article yourselves you can
defy rings. How can they touch you ? (It happened to be a
question of a metal.) You can buy in the markets of the world.
It is produced everywhere. No one can run up the price against
you, and therefore the worst that can happen is that you are on
equal terms with them."

Now some of you will say, " Oh, yes, but is not this a viola-
tion of the chief commandment, c You shall buy in the cheapest
market * ? " Is it ? Remember this, that in considering what
is cheap you must not look at the money that passes, but at the
consequences of the purchase too. The man who says, " I will
buy for five years at a discount of five per cent., with the certainty
that I shall have to pay fifteen per cent, more for the next ten
years," and thinks he is buying in the cheapest market, is, I
suggest, a bad student of economics. It is not buying in the
cheapest market if you buy something which destroys your real
security for cheapness, which prevents you from being over-
charged. And I am perfectly certain that when the idea of loyal
co-operation gets hold of Lancashire and Yorkshire the foes of
England in the industrial world will begin to tremble. We
have had a time of peace in England, and we have never thought
of dangers industrial or national. But there are these dangers,
and even though there may not be another war, as we trust there
will not be, there is perpetual war going on industrially, and it

MANUFACTURE OF DYES IN ENGLAND 363

is not based on the ideas of each man doing his best and of fair
sale and fair purchase. It is based on what in the industrial
world corresponds to war in the political world, and if you do
not realise that, if you will not stand by one another as producer
and consumer, and you let the producer go down under his
enemies, so that in turn they have the mastery of you, then all
I can say is that as consumers you have been buying in the
dearest market, and you will deserve the consequences that
you get.

Now, gentlemen, I have come to the conclusion of which
I told the Government. I have nothing to do with the particular
form in which the Government have followed out that for
which I am responsible as an adviser. You must have a large
company a company with national control so far as to keep
it in the right path ; and you must have a company which is
co-operative between the producer and the consumer. If you
do that, I can warrant it a long and successful life ; but if you
attempt to leave out any one of these three essentials, it is pre-
doomed to failure.

Just let me say one or two words in conclusion. Supposing
our War Minister had been in the last few years buying in the
cheapest market for the sake of cheapness, and that he had
had the munitions of war manufactured by Krupps, of Essen.
Gentlemen, I think he would have been lynched about three
months ago. You would have realised when the moment of
need came that your sources of supply were cut off. Now,
gentlemen, there are munitions of peace which are essential for
the defence of the great industries of the country, which are
vital. There are munitions of peace as to which you have to
take the same precautions as in regard to munitions of war.

You have to realise that, so far as it is possible, a country
should be in such a position that if its supplies are cut off, for
any reason whatever, from outside, it should be able to supply
itself. Of course, we realise that in raw materials and in many
other things we must depend on supplies from outside, and that
is the reason why we are a nation that spends so unstintingly
on its fleet. But this is no question of getting raw materials
from a foreign country. It is a question of being at the mercy
of a country, not friendly disposed, in a matter where we could
make ourselves independent ; and it is a case in which we know
perfectly well what are the morals of that country in regard to

364 THE BRITISH COAL-TAR INDUSTRY

its behaviour to other nations. Therefore I say you must look
upon it as if it were one of those necessary munitions of peace
which you must see adequately manufactured among yourselves.

Some will say there is none here, I trust what I heard
of a great dealer saying, " Oh, but I am a business man. I only
look at things as business propositions, and a tenth of a penny
would make me buy everything from Germany rather than from
England." At that very moment tens of thousands of men
were exposing their lives in the trenches to protect that man
and his money. I wonder how many would have been there if
it was always thought a brilliant thing for a man to look on every-
thing from the point of view of a business proposition ?

If that is being done by the recruits, what are you and I going
to do for our country ? You cannot go to the trenches, and yet
I believe you are all willing and burning to do what you can
for your country. Well, this is your part. You can protect
your country by taking care that when peace comes it shall be
under no subordination. That is what I ask you to do. A
great writer has said, " There is nothing more desirable in life
than to be wise at a great moment." This is a great moment.
Be wise.

XXVII.: 1915

GERMAN CHEMICAL INDUSTRY THIRTY
YEARS AGO

BY THE RIGHT HON. SIR HENRY ROSCOE, F.R.S.

(Journal of the Society of Chemical Industry^ 3Oth January 1915, p. 65)

THE following short report, written by myself for the Royal
Commission on Technical Instruction, of which I was a member,
was printed in 1882. This shows that even in those early years
the Germans had seized upon the methods which have made
their chemical industries so successful, and that money cannot
secure success unless it is accompanied by perfect scientific
method, and above all by the recognition of the importance of
original investigation :

ON THE INFLUENCE OF TECHNICAL EDUCATION ON CERTAIN
BRANCHES OF CHEMICAL INDUSTRY

We have here collected our notes on certain special industries,
viz. (i) chemical colours, (2) beet-sugar, and (3) the alkali trade,
upon which the influence of technical education is plainly
observable.

Influence of Technical Training on the Chemical Colour Industry
of Germany and Switzerland

Among the coal-tar colour works visited by the Commissioners
were those erected on the banks of the Rhine at Basle by Messrs
Bindschedler & Busch. These works, though far less extensive
than those of Messrs Meister, Lucius & Brttning, at Hdchst,
or of the Baden Aniline and Soda Works at Ludwigshafen, are

365

366 THE BRITISH COAL-TAR INDUSTRY

carried on in a no less scientific spirit, and the general method of
working adopted in all these establishments is identical.

The first principle which guides the commercial heads of all
the Continental colour works is the absolute necessity of
having highly trained scientific chemists not only at the head of
the works, but at the head of every department of the works
where a special manufacture is being carried on. In this respect
this method of working stands in absolute contrast to that too
often adopted in chemical works in this country, where the con-
trol of the processes is left in the hands of men whose only rule
is that of the thumb, and whose only knowledge is that bequeathed
to them by their fathers.

On entering the works of Messrs Bindschedler & Busch one
is struck, in the first place, with the adaptation of means to ends,
with the substantially built, well-lighted, well-ventilated work-
shops, and, above all, with the all-pervading cleanliness and
neatness. But it is not of these things that we now desire to
speak, but rather of the method by which their business is
conducted. In the first place, then, the scientific director
(Dr Bindschedler) is a thoroughly educated chemist, cognisant
of and able to make use of the discoveries emanating from the
various scientific laboratories of the world. Under him are
three scientific chemists, to each of whom is entrusted one of the
three main departments, into which the works are divided. Each
of these head chemists, who have in this instance enjoyed a
thorough training in the Zurich Polytechnic, has several assistant
chemists placed under him, and all these are gentlemen who
have had a theoretical education in either a German university
or in a Polytechnic school. An important part of the system
has now to be noticed, viz., that directly under these scientific
assistants come the common workmen, who have, of course, no
knowledge whatever of scientific principles, and who are, in fact,
simple machines, acting under the will of a superior intelligence.
The many and great advantages of this arrangement are patent
to all ; and the fact of having men of education and refinement
in positions of this kind renders the foreign manufacturer who
adopts this system less liable to annoyance and loss (from
sources which we need not more nearly specify) than his English
competitor, who works on a different plan.

So much for the personnel of the works. Now for the mode
in which they carry on their work. To begin at the beginning,

GERMAN CHEMICAL INDUSTRY 30 YEARS AGO 367

we find no less than ten well-equipped, airy, experimental
laboratories in these works, perfectly distinct from the workshops
where the manufacturing processes are carried on. In these ten
laboratories, the chief departmental chemists and their assistants
work out their investigations respecting the production of new
colouring matters, or the more economic manufacture of old
ones. To assist them in their work, a complete scientific library
is at hand containing all the newest researches, for these, as we
have said, form the material out of which the colour-chemist
builds up his manufacture, and no sooner do the results appear
of a perhaps purely scientific research which may possibly yield
practical issues, than the works-chemist seizes on them and
repeats these experiments, modifying and altering them so as at
last to bring them within the charmed circle of financial success.

Thanks to Dr Bindschedler, we are able to quote a specially
representative case, and a clear description of one such case is
worth a host of generalities. Through the original investigations
of Messrs Emil and Otto Fischer, the attention of the manufacturer
was drawn to the leuco or colourless base obtained by the action
of benzaldehyde on dimethylaniline, inasmuch as they stated
that the salts of these colourless bases become green on exposure
to air. Founded on these observations, an endeavour was made
to effect the practical manufacture of a green colouring matter
by oxidation of these colourless bodies. In order to attain the
desired end, the following investigations had to be made by the
chemist and his assistants who were to conduct the operations :

(1) A cheap method had to be found for manufacturing
benzaldehyde.

(2) A profitable mode of making the leuco base had to be
worked out.

(3) The proper oxidising agents and their best method of
application had to be determined.

(4) The best method of purifying and of crystallising the
green colouring matter had to be discovered.

The laboratory experiments on the above points having
proved so far successful as to give prospects of good results,
operations on a somewhat larger scale were started, and these
yielding a satisfactory issue, the manufacture proper of the
colouring matter, now well known as malachite green, on the
technical scale was commenced, all the operations being watched
by and constantly being under the control of the chemists. But

368 THE BRITISH COAL-TAR INDUSTRY

even now their scientific work is by no means ended. Continuous
laboratory experiments go on for the purpose of rinding improve-
ments in the mode of manufacture. Thus, for example, the
improved yield, both as to quality and quantity, of the benzal-
dehyde is a matter of investigation. Again, the synthetic pro-
duction of the pure leuco base by a more direct process is sought
for, so as to get rid of loss in working, and to obtain a yield as
close as possible to that pointed out by theory. In the same
way improvements in the materials used for oxidation, and in
their application, are made, so as to effect the oxidation quanti-
tatively, without the formation of by-products. Lastly, the
action of various solvents is examined, so as to obtain the best
form of the crystallised colouring matter. As indicating the
value of these improvements made after the colour became a
marketable article, it is only necessary to state that the price
of the crystallised oxalate has been reduced from 2 to 1, 43.
per kilo.

The foregoing may serve to give a picture of a really
scientifically conducted works, where each step in advance is
made systematically, as the result of a well-devised plan of
operations. This is, indeed, the only means of progress, and
this fact is so well recognised in Germany that each of the much
larger colour works at Hochst and Ludwigshafen possesses a
staff of from thirty to forty well-paid and thoroughly trained
chemists to conduct their operations.

But we are, of course, far from believing that because the
methods adopted in these foreign colour works are scientific and
productive of good, those made use of in all English works must
therefore be unscientific and bad. Taking the whole applications
of chemical science we may, no doubt, with truth say that the
English industrial chemists have been at least as successful
commercially and certainly as productive in new and important
discoveries as their Continental rivals. The Germans and
Swiss, however, have been and still are distinctly before us, not
only in the facilities which they possess of obtaining the highest
technical training in their numerous universities and polytechnic
schools, but what is even more to the point before us, is the
general recognition of the value and importance of such training
for the successful prosecution of any branch of applied science.

The following statistics give some idea of the magnitude
of the colour works of Messrs Meister, Lucius & Brtlning,

GERMAN CHEMICAL INDUSTRY 30 YEARS AGO 369

at Hflchst, near Frankfort, referred to above, and founded
in 1862.

The establishments occupy an area of 1 50 acres, of which 20
are covered with buildings. The staff includes 51 scientific
chemists, 50 foremen, 15 managers and engineers, and 77 clerks
and commercial men, with 1400 workpeople. The works possesses
its own railways, 41 boilers, with a heating surface of 4000 square
yards, and 71 motors, either steam, water, or gas engines. The
workmen and officials are domiciled in houses belonging to the
company, and restaurants, baths, sick clubs and pension funds
have been established for the good of the employes. There is
also a fire-brigade with 5 hand engines and i steam fire-engine.
The total supply of water, from 145 fire-cocks, amounts to 30,000
cubic feet per hour.

In 1882 the products of these works amounted to :

(1) 6,600,000 Ib. weight of alizarin.

(2) 2,200,000 Ib. weight of aniline oil.

(3) 1,540,000 Ib. weight of aniline, resorcin, and naphthol.

Colours

The following are the separate products classed together
under the last head :

Aniline and aniline salts.

Fuchsine (no arsenic used in its preparation).

Methyl violet.

Green and blue colours.

Eosin colours.

Naphthol colours.

Alizarin and artificial indigo.

Quinolin derivative (kairin, a new substitute for quinine).

Acids.

The most important raw materials employed in manufacturing
the foregoing products are as follows :

40,000 tons coal.
3,000 tar products.
2,400 caustic soda.
400 potash salts.
2,900 carbonate of soda.
17,400 sulphuric acid.

370 THE BRITISH COAL-TAR INDUSTRY

10,100 tons various other acids.
1,500 iron borings and filings.

250 wood spirit and spirits of wine.
1,000 various chemicals.
6,800 common salt.
2,050 carbonate of lime.

The whole of the sulphuric, hydrochloric, and nitric acids
used is made on the works.

From about 70 to 80 per cent, of all the aniline colours manu-
factured are exported, the remainder being used in Germany.

About 90 per cent, of the total make of alizarin is exported
chiefly to England, but considerable quantities find their way to
America, Russia, France, Holland, Spain, and Italy.

One of the most recent and most interesting additions to the
above list of products is a derivative of quinolin, termed kairin,
lately discovered by Emil Fischer. This substance, which is
now being made at Hochst at the rate of about 22 Ib. daily, has
been shown to possess important febrifuge properties, even
exceeding quinine in activity, and it is not impossible that this
artificial product obtained from coal tar may be the means of
supplanting altogether the natural alkaloid. The importance of
this discovery, should it serve the above purpose, can of course
hardly be overrated, and it will then add another and most
striking example to the numerous ones which already exist of the
immense importance to the human race of researches in purely
scientific organic chemistry, which at one time appeared to have
no practical value or possible application. It may, therefore,
serve again to point the moral, which cannot be too strongly
insisted upon, that it is only by the highest and most elaborate
achievements of pure scientific investigation that the greatest
practical advantages to mankind can be secured.

XXVIII. : 1915

THE MANUFACTURE OF DYESTUFFS
IN BRITAIN

BY PROFESSOR W. M. GARDNER, M.Sc., F.I.C.

A SUMMARY AND AN APPEAL
(Nature^ 2ist January 1915, p. 555)

THE speech of Lord Moulton in Manchester on 8th December
1914 was a notable event, even in these days of strenuousness
and surprise. For although he was careful to disclaim any official
sanction of the views he expressed, it was common knowledge
that the Government had requisitioned his services in investigat-
ing the question of the shortage of dyestuffs, and had based its
policy largely on the advice he gave as the outcome of his
investigation.

The general outline of the crucial position in which the
British textile trades are placed at the present time is well
known. At least 1,500,000 operatives are engaged in the
various branches of the trade, which has an annual value of
200,000,000. Nearly the whole of this vast industry depends
for its commercial success upon the use of dyestuffs, which cost
about 2,000,000 per annum, and only about 10 per cent, of the
necessary quantity of dyestuff is made in this country. Before
the war, between 80 to 90 per cent, of our dyewares was
imported from Germany, and this supply is now entirely cut off.
Unless, therefore, immediate steps are taken greatly to increase
our national output and the supply from neutral countries (chiefly
Switzerland), a catastrophe will very quickly overtake the great
textile and associated industries.

372 THE BRITISH COAL-TAR INDUSTRY

The magnitude, gravity, and imminence of the crisis clearly
pointed to the necessity for Government action, and a " Chemical
Supplies Committee " was appointed to confer with the Board of
Trade on the position. This committee included a number of
well-known chemists, and manufacturers and users of chemicals
and dyestuffs. The investigations of Lord Moulton and of this
committee are understood to have formed the basis from which
the offer of the Government was developed, but the committee
was apparently not responsible for the details of the scheme for
the establishment of a large Joint-stock Dye-manufacturing
Company, which was made public on 22nd December 1914.

Prior to this, on roth December 1914, a meeting of large
users of dyes was held at the Board of Trade, at which a resolu-
tion was unanimously passed welcoming the assistance of the
Government in a national effort to increase the British supply of
dyes. A small committee, representative only of the users of
dyes, was appointed, and elaborated the scheme to which reference
has already been made for the formation of a manufacturing
company.

An influential committee, appointed by the Society of Dyers
and Colourists, has also made exhaustive inquiries on the tech-
nical side and has accumulated much valuable information.

It is well known that there are enormous difficulties involved
in establishing on a permanent basis the manufacture of dyes on a
scale adequate to supply our needs, and that without Government
or legislative assistance they might well prove insurmountable ;
and the action of the Government in proffering such broad-
minded and generous support has received, as it deserved, the
recognition of all parties.

The German colour industry is probably the most compli-
cated, most highly developed, and most profitable of all her great
industries. The capital invested in it is about .12,000,000, and
the German exports of dyes and associated products in 1912
were valued at 10,600,000. The organisation, both for pro-
duction and for marketing and distribution, is wonderfully
efficient, and above all the Germans have long realised that in
this branch of industry the scientific mind and scientific method
must be predominant, not only in the laboratory and in the
works, but in the management. The boards of directors of their
large works are virtually committees of technical and commercial
experts who are in intimate touch with the respective branches of

MANUFACTURE OF DYESTUFFS IN BRITAIN 373

the works of which they have special knowledge. In a word,
the trained man of science has in these works come to his own,
and a proper recognition of the necessity of this is vital to the
development of the British colour industry.

The reasons for the predominance of Germany in this
particular industry have been frequently and variously stated,
but it is now generally conceded that there is no lack of highly
trained chemists in this country competent to build up a com-
mercially successful enterprise. With regard to other factors,
we have, of course, a superabundance of the coal-tar products
which form the basis of the manufacture, but the manufacture
of certain essential reagents, e.g. fuming sulphuric acid, though
already existing, will have to be greatly increased.

Government assistance will be required in regard to the
provision of cheap alcohol, and the resources and skill of the
chemical engineer will be heavily drawn upon to provide the
essential apparatus. A great number of chemists will be needed
to work out the details of known processes, first on the laboratory
scale, and later on a bulk basis, and the well-equipped laboratories
and staffs of the universities and larger technical institutions
might well be pressed into service for much of the preliminary
work. Many chemists will also be required for developing new
processes and for other research work, because of no other in-
dustry can it be so truly said that stagnation spells failure.

The great complexity of the manufacture of dyestuffs is not
due to the use of a large number of raw materials, the direct
products from coal tar being only nine or ten. By chemical
treatment these are, however, transformed into 250 to 300
different intermediate products which, in their turn, yield some
1 200 chemically distinct dyestuffs. In some processes of manu-
facture high temperatures and pressures are required ; in others
the temperature must be reduced, and a large refrigerating plant
is an essential feature of a colour works.

Surely, then, it is abundantly evident that the technical expert
must be the preponderating element in the dye factory, and that
he must have a large share in the management and control.
The British custom of entrusting the management of large
concerns to financiers, commercial magnates, and "men of affairs"
has done much to retard the scientific development of our
industries, and the adequate representation of the technical expert
on the directorate is vital to the success of the new scheme.

374 THE BRITISH COAL-TAR INDUSTRY

Lord Moulton laid down three propositions with regard to
the proposed new British dye-manufacturing company. It must
be large enough to be able to face severe competition at the end
of the war. It must be, and must remain, entirely British, and
it must be co-operative ; and all these conditions are fulfilled by
the scheme put forward. It is proposed that the share capital
shall be 3,000,000, and the Government offers to supplement
this by a loan of 1,500,000 at 4 per cent, and repayable in
twenty-five years. The four and a half millions of capital thus
proposed is probably ample to establish and develop an industry
which would make us independent of imported products.

The proposals with regard to co-operation are that dyers and
others associated with the consumption of the products, e.g.
spinners, manufacturers, merchants, textile machinists, etc.,
should take shares in the new company and thus become
interested in its success. This is quite sound and receives
general acceptance, but certain suggestions in the prospectus with
regard to a pro rata subscription appear to be unworkable.

The Government reserves the right of appointing two
directors of the company, and it is much to be regretted that the
opportunity has not been taken of giving a wise lead in regard
to the character of the directorate, by stipulating that the scientific
technologist should be adequately represented.

Another feature of the scheme propounded by the committee
is that certain existing colour works are to be taken over by the
new company to form the nucleus of development. The
resources of these works are to be extended as rapidly as possible
in order to cope with immediate necessities and prevent an actual
famine in dyewares in fact, large extensions are at the present
moment being made.

A point which presents some difficulty in adjustment is the
relationship of the new company to existing British dye-produc-
ing firms, or such as may be established in the future. It is
obviously not desirable to stifle private enterprise by anything in
the nature of a monopoly supported by the Government, but the
existence of successful German firms which are outside the two
great " Interessengemeinschafte," or rings, indicates that the
difficulty is more apparent than real. A somewhat cognate
matter is the future relationship of the new company to the
Swiss firms which are importing to us during the present crisis.

The various criticisms of the Government schemes which

MANUFACTURE OF DYESTUFFS IN BRITAIN 375

have been offered refer, not to general principles, but in almost
all cases to more or less important details. The general outline
of the scheme the establishment, by co-operation of those
specially concerned, of a new company with great resources and
financially aided by the Government has received general
approval, and the unprecedented step taken by the Government
has been applauded by men of all parties, as meeting an industrial
crisis in a bold and statesmanlike manner. In response to this,
and in recognition of a national emergency, it is the obvious duty
of all who are commercially interested to deal with the question
from the national rather than from the individual point of view.
Support of a scheme for the manufacture in Britain of British-
used dyes is, at its lowest estimate, an essential business insurance,
and on a higher plane it is helping forward a movement to free
our great textile industry from the danger of German domination.
Apart altogether from the commercial aspect, there is, therefore,
a great obligation of patriotism involved. The scheme put
forward possibly as a ballon d'essai as regards details certainly
requires modification, but from it can be elaborated a national
and co-operative effort which is bound to succeed. Let us all
take as a starting-point of our deliberations that the thing must
be done, and then the details of how to do it will fall into proper
perspective.

Finally, it may be pointed out that incidental advantages of
enormous national value will accrue as the result of the successful
fruition of this dyeware manufacture scheme. The necessity
for dealing with our industries from a national, rather than an
individualistic, point of view will be more fully recognised by the
Government and by the public. The necessity for the use of
scientific method and control of our industries will be strongly
emphasised. The claims of patriotism and the value of co-
operation in commercial matters will receive fuller consideration.
And lastly, the establishment of a powerful company for the
manufacture of organic dyestuffs will afford protection to our
great industries concerned in the manufacture of inorganic
chemicals, an attack on which was beginning to be organised.

Now is our opportunity, and everything is propitious.
Patriotism and self-interest are alike clamouring for the establish-
ment of a large dye-manufacturing concern, and the Government
offers its support. One essential thing may, however, be over-
looked the new company is foredoomed to failure unless a

376 THE BRITISH COAL-TAR INDUSTRY

scientific rather than a purely commercial spirit permeates the
management, and an appeal is made to the Government and to
the eminent business men forming the committee who have
issued the scheme that in its final form it may include a full
recognition of this fundamental point.

THE GOVERNMENT'S MODIFIED SCHEME
(Nature^ 25th February 1915, p. 700)

The discussion on the various aspects of the problem of pro-
ducing in this country an adequate supply of dyestuffs proceeds
without intermission. The question has for some time assumed
a national aspect and has been the subject of Parliamentary debate
or question on at least three occasions. It has also been debated
at meetings of the Chambers of Commerce in the chief industrial
centres, and people most directly interested have had many
opportunities of expressing their opinions at meetings of their
various organisations, or at gatherings specially convened for
the purpose.

To a great extent the discussions have centred round the
adequacy and equity of the commercial proposals involved in
the official scheme now before the public. These have received
much more general acceptance than those put forward in the
first scheme, and it appears probable that the committee has now
received promises of support to an amount representing a
substantial proportion of the initial capital proposed for the
new company.

The members of the committee themselves admit that it is
an easy matter to criticise the scheme adversely, and it is
obviously impossible to devise a solution of the problem
satisfactory to all minds.

If the matter is to be viewed as an ordinary commercial
proposition, if questions of free trade or protection are to be
taken into account, or if early dividends are to be assured, then
any scheme which might be put forward could be shown to be
unworthy of support. But whilst criticism on these lines has
been plentiful, there has latterly been a rally of support by those
taking broader views a support which has probably been largely
induced by a sense of national need, and has certainly been

MANUFACTURE OF DYESTUFFS IN BRITAIN 377

greatly developed by the action of the Government in offering
to endow the research work which is essential to the extent of
; 1 00,000. This action has engendered a feeling of confidence
that the Government will take any further steps which the future
may show to be vital to the success of the British dye-
manufacturing industry.

It is to be hoped that the committee in charge of the scheme
will shortly be able to announce the results of its inquiries, and
that these will show that the great textile trade of the country
has responded adequately. In the meantime, the arrangements
for carrying out the necessary preliminary chemical work should
be proceeded with.

A Mobilisation of Chemists

Speaking in Bradford on 8th February, the present writer
advocated immediate action by the Government or the Board
of Trade Advisory Committee in the direction of utilising the
services of British chemists. There is on one hand a large
amount of chemical work to be done before the industry can
be greatly developed, and on the other there are a great number
of well-staffed and well-equipped laboratories in our universities
and technical colleges which might render great service to the
industry. To avoid wasteful duplication of work and to co-
ordinate the results, it is essential that some organised scheme
and allotment of work should be arranged, and it is suggested
that a conference of those concerned should be held at an early
date to formulate such a scheme. Even if to-morrow the whole
of the available chemical force set to work on some organised
plan, it would not be any too soon to get the necessary informa-
tion together for the use of the existing works and the new
works when they are started.

The urgency of this action is further shown by a resolution
passed by an important meeting held in Manchester on i6th
February, which was presided over by Sir Charles Macara.
The resolution, which was carried unanimously, stated : "That
in the opinion of this meeting the Government would do well
to organise immediately the present chemical talent in the
country with a view to chemical research being undertaken
for, and on behalf of, all manufacturers interested, and that
the services of these experts should be available for all desirous
of availing themselves thereof.'*

378 THE BRITISH COAL-TAR INDUSTRY

The adoption of such a plan for bringing the educational
institutions more closely into touch with the industries would
in all probability mark the beginning of a new era in which both
would benefit. The more intimate association of professors of
chemistry with chemical industry would introduce into the works
that higher ideal and broader scientific spirit upon which successful
research and development depend, whilst the schools would
benefit by the great incentive of practical reality.

XXIX.: 1915
THE CHEMICAL INDUSTRIES OF GERMANY

BY PROFESSOR P. FRANKLAND, F.R.S.
[Abstract]

(Nature, nth March 1915, p. 47; Journal of the Society of Chemical
Industry^ April 1915, p. 307)

THE interest and importance of the subject at the present time
are sufficiently obvious. In outlining some of the origins of
chemical industry in Germany, the lecturer pointed out how the
royal house of Prussia had been frequently associated with
chemical enterprise. The Markgrave John was actually sur-
named " the Alchemist " ; the Great Elector was a patron of
chemistry and provided a laboratory at Potsdam for the celebrated
Kunkel, one of the first to discover phosphorus, and who also
effected great advances in the manufacture of glass. Frederick
the Great established the Royal Berlin porcelain factory, which
still occupies some of the original premises. In the same reign
also the chemist Marggraf made those classical investigations on
the occurrence of sugar in the vegetable kingdom which later led
to the foundation of the beet-sugar industry, which was initially
subsidised by Frederick William III., the founder of the Uni-
versity of Berlin in 1809. (^ n I 9 I 4> tne Berlin University had
12,585 students, and received an annual grant from the State of
more than 200,000.)

Great industries have developed out of these early steps.
From the discovery of phosphorus came the match industry.
The German annual production of matches is 4,600,000 ; the
British production in 1907 amounted to 775,000, whilst the
British consumption in 1910 was estimated at 1,300,000.
Again, the porcelain and pottery manufacture had attained great
dimensions in Germany, the exports in 1912 amounting to

379

380 THE BRITISH COAL-TAR INDUSTRY

3,556,000, whilst the glass industry was even on a larger scale,
the recent annual exports being more than 7,000,000. Great
inconvenience in connection with all scientific work is at present
being experienced through the absence of German glass. The
important cyanide industry may be said to have taken its origin
from the accidental discovery by Diesbach, of Berlin, of Prussian
blue in the first decade of the eighteenth century. Germany's
annual production of cyanides is now estimated at 10,000 tons
(650,000), or about one-half of the world's production.

The beet-sugar industry exemplifies how agricultural pro-
duction can be improved by systematic research such as has been
bestowed on it by Germany ; thus :

In 1840 100 Ib. of beet yielded 5*9 Ib. sugar.

1850 7-3

1870 8-4

1890 12-5

1910 15-8

Again, in

1871 mean yield of beet per hectare of land was 246 quintals.
19! >i 3

And again, in the economy of manufacture

In 1867 coal used on 100 Ib. beet . . . . 35 Ib.

1877 ... 24

1890 . 10

19 -7

The former supremacy of Great Britain in the manufacture
of the common chemicals sulphuric acid and soda was referred
to and compared with the production of these materials in 1910.

PRODUCTION IN TONS, 1910

Germany. England. France. United States. World.

Sulphuric acid . 1,250,000 1,000,000 500,000 1,200,000 5,000,000
Soda . . . 400,000 700,000 200,000 250,000 2,000,000

The substitution of the ammonia-soda for the earlier Le Blanc
soda process, and of the contact for the time-honoured leaden
chamber process of sulphuric acid manufacture, had no doubt
greatly assisted both Germany and America in becoming inde-
pendent of the British manufacture of these chemicals.

During the past twenty-five years the manufacture of chlo-
rine and caustic soda by the electrolysis of common salt (sodium
chloride) has been realised and rapidly extended. This process

THE CHEMICAL INDUSTRIES OF GERMANY 381

is carried out on a very large scale in Germany, where extensive
use is made of liquefied chlorine. The production of electrolytic
chlorine is attended with the simultaneous evolution of large
quantities of hydrogen gas for which uses have been found;
thus, for filling the dirigible balloons upon which such hopes of
conquest have been based by Germany, whilst in the oxyhydrogen
flame it has been employed for welding, for the cutting even of
thick iron structures, and for the manufacture of artificial gems.
The artificial production of gems corundum, ruby, sapphire,
etc. was discovered in France by Michaud, Verneuil, and
Paquier, and has been greatly taken up by the Elektrochemische
Werke at Bitterfeld, in Germany. More than a ton of these
gems, which are identical in chemical composition with the natural
gems, are said to be annually produced. Other more important
uses for hydrogen have been found for the hardening of fats, and
still more recently for the synthetic production of ammonia to be
presently referred to, and which is an industrial achievement of
the first magnitude. Cheaper sources of hydrogen than the
electrolytic method have been introduced, and notably that de-
pending on the production of water-gas (consisting of equal
volumes of hydrogen and carbon monoxide) from steam and
coke at a red heat, the carbon monoxide being subsequently
separated from the hydrogen by liquefying it by means of the
low-temperature apparatus of Carl von Linde, of Munich.

AMMONIA, NITRATES, AND FIXATION OF FREE NITROGEN

As is well known, one of the most important problems at
the present time is to provide the world with nitrate when the
deposits in Chile shall have been exhausted. The problem is
bound up with the still wider one of the fixation of atmospheric
nitrogen. This again, as is well known, is now accomplished on
a large scale by the production of nitric acid from atmospheric
nitrogen and oxygen by means of the electric furnace of Birkeland
and Eyde, or by the production of calcium cyanamide by passing
atmospheric nitrogen over heated calcium carbide. Both these
processes involve the use of the electric furnace, in the former
for effecting the union of the nitrogen and oxygen, and in the
latter for the preliminary production of the calcium carbide.
Abundant water-power being necessary for the economic opera-
tion of the above processes, Norway has become their chief centre,

382 THE BRITISH COAL-TAR INDUSTRY

whilst Germany has sought other means of nitrogen-fixation which
could be carried on within her own territories. The synthesis of
ammonia from hydrogen and atmospheric nitrogen under a pressure
of 200 atmospheres and at 500 C. in the presence of a catalyst,
has been successfully worked out by Haber in conjunction with
the Badische Anil in- und Soda-Fabrik, and a plant capable of
yielding 130,000 tons of sulphate of ammonia per annum was to
have been ready in 1915. The second step in the German pro-
gramme was to convert the ammonia into nitric acid by burning
it in air in the presence of a catalyst. In this way it is hoped to
make Germany independent of foreign countries for the nitrate
required in the manufacture of explosives. It is asserted that
this independence Germany has actually secured at the present
moment.

EXPLOSIVES

Of the modern high explosives, gun-cotton was discovered
by Schoenbein and by Boettger in 1846. The manufacture of
nitroglycerine (discovered by Sobrero in Paris in 1847) was
first realised by the Swede, Alfred Nobel, in 1862, and it was
Nobel who first adapted these powerful explosives for ballistic
purposes. Trinitrotoluene, of which so much has been heard
recently, was first proposed for filling shells by Haessermann in
1891. It is said to be surpassed, both as regards safety and
disruptive effect, by tetranitro-aniline discovered in England by
Dr Fluerscheim. The great magnitude of the German explosives
industry is seen from the following figures :

Tons.

Total German production of explosives . . . . 40,000
or about one-tenth of the estimated world production.

Germany exported in 1908 to the value of . . 1, 000,000
1912 3,000,000

ARTIFICIAL SILK

This remarkable industry, originated by Count Chardonnet
in France in 1891, has also been largely developed on German
soil. The German production amounts to about 2000 tons
annually (1,200,000) out of a total world production of about
7000 tons. French, German, and British patents have largely
contributed to the success of this industry.

THE CHEMICAL INDUSTRIES OF GERMANY 383

INDUSTRIES DEPENDENT ON SYNTHETIC ORGANIC CHEMISTRY

It is in respect of these industries that the world is learning
that Germany holds the undisputed supremacy. It is in Germany
alone that manufacturers have been found prepared to embark
their capital and undertake industrial enterprises of the first
magnitude on the advice of the organic chemist. The success
which has been achieved by the German manufacturers of artificial
dyestuffs, drugs, and perfumes, and the hegemony which they
have secured in this branch of industry, has been the frequent
subject of warning by professors of chemistry in this country for
upwards of a generation. The seriousness of the situation which
has arisen through the neglect of those warnings is seen from the
following figures :

Annual value of dyestuffs used in Britain .... ^2, 000,000

trade in which these dyes are employed . 200,000,000

Workmen dependent on this trade, 1,500,000

Total value of dyestuffs imported (1913) into Britain . 1,892,055

,, from Germany . . 1,730,821

Less than one-tenth of the annual value of the dyestuffs
consumed in England is produced in this country. Thus, by
controlling the dyestuff industry, Germany indirectly holds in
her grip the whole of the textile industry.

Much inconvenience has been experienced also in the shortage
of artificial drugs and consequent high prices, more especially at
the beginning of the war, as even the simplest of these products
were almost exclusively made in Germany. The manufacture of
some of these is, however, now being successfully carried on in
England.

Again, the shortage of organic chemicals required for research
purposes, which practically all come from Germany, is occasioning
most serious difficulties in our university laboratories.

For the manufacture of dyestuffs and similar synthetic pro-
ducts Germany was formerly largely dependent on England
for the raw material coal-tar. But in this case, again, the
ambition of Germany to become in all respects independent and
self-contained has led her in recent years to make the most
strenuous efforts to recover the maximum amount of coal-tar
both from the manufacture of gas and from coke-ovens, which
endeavour has been assisted by the enormous growth in her iron
and steel industries. Thus in 1897 Germany obtained only

384 THE BRITISH COAL-TAR INDUSTRY

52,000 tons of coal-tar from coke-ovens, whilst in 1908 she
obtained no fewer than 632,400 tons from that source, besides
300,000 tons from the manufacture of gas. Thus at the present
time the German output of coal-tar about equals, if it does not
exceed, that of England.

The German production of artificial perfumes is said to
amount to a value of about 2,500,000 annually. In this
department of applied chemistry, again, one of the first steps
was made by the late Sir William Perkin, by the synthesis in
1868 of coumarin, the much-valued odoriferous principle of
woodruff {Asperula odorata].

The effect of artificial synthesis on the price of natural
perfumes may be gathered from the following examples :

Price of I kilo.

Natural.

Synthetic.

Coumarin ....
Vanillin ....
Heliotropin ....

25
5

s. d.
i 5 o

I IO O
IO

The proposal of the Government to assist the British coal-tar
colour industry is being watched with the greatest interest both
by manufacturers and chemists. The problem of relieving the
immediate shortage during the war must be carefully distin-
guished from the later problem of securing the independence
of the home industry after the war by greatly increasing the
British output. The realisation of the latter object will be
attended with the greatest possible difficulty. The industry will
require " nursing " for a great many years. The undertaking
must be possessed of such elasticity that it can ramify into other
branches of chemical or other industry whenever advantageous
opportunities arise for such departures.

The great magnitude of the German coal-tar colour industry
may be gathered from the fact that the two groups into which
the principal firms are associated have at the present time a total
share capital of about 12,000,000, on which a dividend of about
28 per cent, is paid. In 1912 Germany produced dyestuffs to
the value of 12,500,000, of which to the value of 10,000,000
were exported.

THE CHEMICAL INDUSTRIES OF GERMANY 385

The above facts speak for themselves and proclaim in the
most convincing manner the stupendous progress which has been
made by Germany in the chemical industries during the past
forty years. It is equally certain that England, once pre-eminent
for chemical manufactures, has not progressed at the same rate and
is at the present moment suffering much inconvenience through
being so largely dependent on German chemical products of one
kind and another. The country is now reaping the harvest of
humiliation which it has sown for itself in spite of the warnings
repeated ad nauseam during a whole generation. The systematic
neglect of chemical science and the failure by manufacturers to
utilise the services of highly qualified chemists, could only lead to
the result that all the industries which are dependent on a pro-
found knowledge of chemistry should tend to disappear from our
midst and pass into the hands of those who are prepared, not only
to apply new chemical discoveries to industry, but even to prose-
cute the most varied chemical investigations in the hope of sooner
or later making discoveries which shall be of advantage to their
commercial undertakings. The mischief caused through the neg-
lect of chemistry by practical men in this country has been so subtle
that to a large extent it has remained concealed from the average
man of intelligence and from the governmental classes. During
the past forty years our country has been accumulating wealth
in an altogether unprecedented fashion, so that the loss or
restriction of some industries appeared a matter of no importance
to political observers taking only a broad and superficial survey
of the national resources. The whole of our arrangements have
evolved during the past half-century on the assumption that this
country would never again be engaged in a European war, whilst
still more recently the new democracy has vainly boasted that
it could prevent such a war by means of a general strike. The
year 1914 has seen the dissolution of many fools' paradises
and has given the coup de grace to all these vain imaginings, with
the result that we find our vast textile industry in serious peril
because the much smaller dyestuff industry has been complacently
allowed to slide into the hands of our sagacious and more pains-
taking enemies. The same carelessness and want of foresight
had even allowed us to become dependent on Germany for some
of the most important materials used as explosives, e.g. trinitro-
toluene, and for many of the most valued drugs required alike
by our Army, Navy, and civil population.

386 THE BRITISH COAL-TAR INDUSTRY

The complete breakdown in our supply of fine chemicals,
which is the direct outcome of the disregard of the constant
warnings emitted by scores of British chemists, has led the
Government of the day to intervene and attempt to remedy
the intolerable state of affairs which has arisen in connection with
the supply of coal-tar colours.

We devoutly hope that success will attend the endeavour
to establish the coal-tar colour industry in these Islands on the
largest possible scale. Whatever the ultimate scheme adopted
may be, I would venture to point out that it must be based on
a clear understanding of the following considerations : (i) That
the provision of the required chemicals during the continuance of
the war is one thing, and that their production on a commercial
basis after the cessation of hostilities is quite another matter.
(2) It appears to me that in order to provide the needful supply
during the war, the only reasonable course is to assist in every
possible way those firms which are already making similar or
closely allied products so as to enable them to produce their
present goods on a larger scale, and as far as practicable to
undertake the manufacture of others which are urgently re-
quired. The immediate problem will be also greatly facilitated
by utilising supplies obtainable from neutral powers, and more
especially from Switzerland, which is the only country, other
than Germany, in which the manufacture of dyestuffs and similar
chemical products has been vigorously prosecuted. (3) As regards
the prospects of the home industry after the war, it will require
" nursing." I use the term advisedly in order to obviate the
employment of another and much more familiar one which is so
dear to some politicians and so hated by others ; it will require
nursing for a much longer period of time than has hitherto been
mentioned. In this connection I would point out that the sum
of 1 0,000 a year for ten years, which it has been proposed to
guarantee for research purposes, is absurdly inadequate. (4) If
the industry is to prosper it will not only have to manufacture
materials already known, but also continually to be introduing
new products of its own discovery, as well as constantly to be
seeking to produce more economically a great number of auxiliary
chemicals required in the manufacturing processes. It is also
essential that the undertaking should branch out into the
manufacture of other materials as occasion may arise for
advantageously utilising by-products. (5) The competition

THE CHEMICAL INDUSTRIES OF GERMANY 387

which the industry will have to suffer from Germany is likely
to be much more serious than is generally supposed, because it
must be remembered that England only takes, as we have seen,
about one-fifth of the total German exports of dyestuffs, so that
it would be comparatively easy for German firms specially to
reduce the price of the goods sent to England. They have
already done this in America when attempts have been made to
start a dyestuff industry there. It is particularly significant, and
augurs ill for the prospects of this scheme to rehabilitate the
coal-tar colour industry, that the latter has failed to flourish
anywhere excepting on German soil, and that countries with
fiscal systems entirely different from our own have been no more
successful in this respect than have we ourselves. (6) It will
certainly be necessary that expert chemical knowledge should
in the future be much more highly remunerated than it has been
in the past, otherwise the supply of able and properly qualified
men will not be forthcoming. The flow of men of high-grade
intelligence into a profession is determined by the prizes which
the profession has to offer, in the form of money and social
position. Consider the great stream of able men who are attracted
to the English Bar, in which profession the prizes, although
limited in number, are of the most substantial kind, with the
result that the successful leaders are selected by the fiercest
competition in a very wide field. If there is to be a large influx
of high intelligence into the chemical profession, it will be
necessary that there should be some very different prizes from
the paltry bait which is offered at the present time, for the study
of chemistry in this country now only draws those men who
either have or think they have an overpowering zeal and passion
for the science, to which they devote themselves against the
advice of their friends. Notwithstanding the absence of material
inducements, I venture to say without fear of contradiction that
there is more original investigation being prosecuted in this
country by chemists than by any other body of British men of
science, and this I attribute to the fact that such a large proportion
of our number have either been at German Universities or are
the pupils of those who have been at these centres of research.
Nor are any of us, I am sure, even during this unfortunate crisis,
unmindful of the hospitality and the inspiration which we have
received in the schools of the enemy. (7) If the proposed under-
taking is to succeed, real chemists must be on the directorate,

388 THE BRITISH COAL-TAR INDUSTRY

and in a sufficient proportion to give effect to their views. Many
men of science are excellent business men. What does experience
teach in the case of flourishing chemical industries which we for-
tunately still have amongst us ? What does not the firm of
Messrs Brunner, Mond & Co., for example, owe to the late Dr
Ludwig Mond, F.R.S. ? (8) In attempting to establish a com-
mercially successful coal-tar colour company on a large scale in this
country, I venture to think that the Government have undertaken
a task which they will find to be surrounded with difficulties of
quite a different order from those which they have had to
encounter in some of their most striking previous legislative acts,
such as the provision of salaries for members of Parliament, the
granting of old-age pensions, and the establishment of a compul-
sory system of insurance. These are matters in which if the
Government dictate we are obliged to obey ; but the commercial
success of an industry which is based upon progressive scientific
investigation depends upon factors so subtle and elusive that
they cannot be coerced even by a majority of the House of
Commons. (9) If the chemical industries are to be rehabilitated
in this country, there must be a complete change in the attitude
of mind towards science in general, and towards chemical science
in particular, amongst the influential classes of the population,
and it will certainly not be effected by following the precept
" Business as usual," but by pursuing a policy which is the
exact opposite of what is implied by that phrase.

XXX.: 1915

PATENT LAW REFORM
BY J. W. GORDON, K.C.

(Journal of the Royal Society of Arts, I2th March 1915, p. 356)

(THE first portion of the paper gives a very interesting summary of the
development of technical education in England and in Germany?)

In the year 1867 all the world was looking admiringly upon
the high development and great prosperity of British industry.
Just as we to-day speak with respect of the technical educational
institutions of America, France, Switzerland, and Germany, so in
1867 those other countries were speaking with the like respect of
our widely diffused mechanics' institutes and art schools. Sir
Bernhard Samuelson, who was in personal contact with our
industrial neighbours while at the same time he was an enterprising
industrial captain himself in this country, was by no means
satisfied that these developments, which attracted the favourable
notice of our neighbours, were sufficient to do justice to our-
selves. At great personal trouble and expense he produced a
report of which Mr Mundella, the Minister for Education, in
1 88 1 spoke in high praise, as a State document. In 1882 Sir
B. Samuelson became the Chairman of the Royal Commission
known as the Duke of Devonshire's Commission. In 1897 the
same Commission produced a second report, in which the further
development of the technical education and institutions of
Germany was made the subject of comparison with the past and
with our then existing system. The appearance of the second
report of the Commission gave rise to an important newspaper
discussion which furnished the occasion for a very remarkable
utterance by Sir Bernhard Samuelson, in a short letter which
appeared in the Times of 25th January 1897, and runs as
follows :

389

390 THE BRITISH COAL-TAR INDUSTRY

"In your leader on the report of my late colleagues on
technical progress in Germany, you refer to the fact that the
production of dyes from coal tar, in which we have been so
completely distanced by the Germans, was originated by Dr
Perkin, and, it might be added, by Dr Hofmann, in this country.

" It is not generally known that we lost this manufacture
because the trade in England was shut up for fourteen years by
a master patent whilst no controlling patent had been sanctioned
in Germany, so that anyone could take up the manufacture there ;
the result being, of course, development abroad in place of
stagnation at home.

" At the present time we in this country are handicapped as
much as before, but from an opposition (sic) of things. The
Germans, having taken the lead with their acquired experience
and large capital, keep it by patenting their new processes in this
country, but carry out their manufacture abroad. So long as
they keep our market supplied, which they take care to do,
nobody is at liberty to make the patented articles here."

The case to which allusion was made in the last paragraph
was an action tried in our own courts in 1883, anc ^ brought
by the Badische Chemical Factory against Levinstein & Co.,
a firm of dye manufacturers in Manchester. Seldom has an
action of greater practical importance been the subject of pro-
ceedings in a court of law.

The German patentees in that case were the inventors of a
dyestuff, a chemical body having a definite chemical composition
and a specific name. It may be sufficiently identified by speaking
of it as a sulpho acid of a coal-tar product yielding red and brown
dyes. In respect of the dyestuffs which they were the first to
produce, the German patentees obtained a British patent which
was unquestionably good. Those dyestuffs, however, were of
no appreciable commercial value.

The patent was taken out in 1878, and it was five years later
that the action against Levinstein came to trial. The patentees
then complained that a very successful red dye which Levinstein
manufactured was an infringement of their patent. In the view
which the court took of the nature of the patent this claim was
upheld, and judgment accordingly was given in their favour. But
the circumstances were very singular, and such as to place the
court in a difficult position when deciding upon the issue of fact.
It was proved that the dye which Levinstein manufactured could

PATENT LAW REFORM 391

not be produced by the processes which the inventors had
described, indeed could not be produced by any process which
was known to the inventors. The successful dye, which was
taken to answer to the chemical composition of the patented
invention, was produced by a secret process, and special arrange-
ments were made for taking the evidence in such a manner that
the Levinstein secret was not disclosed except confidentially to
the court and its officers. The patentee, therefore, although he
was allowed to restrain the second inventor from working his
own invention in this country, did not acquire a knowledge of
the nature of that invention. Thus the action resulted in a
deadlock, and the operation of the patent law in this case was
to banish the manufacture of the patented dye from this country
altogether. The patentee could not make it because he did not
know how, the real inventor could not make it because he was
restrained by an injunction of the court. So it happened that
by this perverse operation of the patent law a patent, which had
been granted with the avowed object of introducing into this
country the manufacture of the sulpho-acid dyestuffs, operated
to prevent their introduction. In the end the manufacture was
carried on in Holland, where the German patentees had been
unable to obtain a patent. No statistics have been published
from which the value of the dye industry which was thus trans-
ferred to Holland can be ascertained, but credible information
goes to show that the cloth sent from Manchester to Holland to
be dyed with Blackley red represented an industry which, in the
aggregate, was worth many millions of pounds, and Sir Bernhard
Samuelson's warning is of special importance at a moment when
the investment of a large sum of money is in contemplation with
the object of establishing an industry similar to that which was
so ruthlessly destroyed by legal process in 1883.

Now, in a case like this it is quite impossible to attribute the
loss of the industry to any defect in our system of technical
education. In 1883 a Patent Act had been passed by which
provision was made, among other things, for the remedying of
the mischief which this case illustrates. It is not, however, to be
supposed that the draftsman of that statute had the facts of the
Levinstein case in mind. That, indeed, was impossible. The
Act was passed in 1883, and the action was only tried in that
year. The consequences of the decision in that action could not
possibly have been known until a later date. But although it

392 THE BRITISH COAL-TAR INDUSTRY

had not been illustrated on so large a scale, the mischief was
perfectly well known to students of our industrial development
in 1883. It is not surprising, therefore, to find that an attempt
was made to remedy the mischief.

It has been shown that the operation of the patent law in
the Levinstein case was to render the use in this country of a
valuable invention impossible, and to banish the resulting industry
to Holland. It needs no argument to show that that is a
complete miscarriage. The object of the patent law is to
facilitate the introduction of new manufactures within the realm.
Whether we look upon the patent as an instrument of public
policy, or as a reward granted to a meritorious inventor, the
result from this point of view is the same. The merit of the
inventor or the object of the policy, as the case may be, is to
secure the advantage of an improvement in manufacture for the
benefit of the people of this realm. In law, no less than in
policy, the outcome of the Levinstein case was absurd and
lamentable. How, then, could such a result come about ? The
answer to that question is that it came about by the operation of
the rule which makes an injunction by the court the remedy for
an infringement of patent right.

In spite of the stringent provisions of the Statute of Mono-
polies (1624) the injunction is to-day what it was in the days of
Elizabeth and James I., the main support of patent right, and, as
the case quoted shows, it has been used in modern times with
effects even more disastrous for the industry of this country than
in those ancient days, when it aroused the hostility of Lord Coke
and the antagonism of a reforming Parliament.

Enough has been already said about the mischievous effect
of this particular injunction upon the dyeing trade of Lancashire.
But the facts cover a very much larger field than this particular
sulpho-acid dye, a field in fact much larger than the field of
dyestuffs, a field which is larger even than the whole chemical
industry. But we are more immediately concerned with its
bearing upon the proposal to establish dye manufacture upon a
very extensive scale within this country.

From that point of view the important fact in the Levinstein
case is, not that the manufacture of a particular dye was pro-
hibited within the realm, but that the way of improvement was
closed. The peculiar mischief of this decision was that it made
it more advantageous for an inventor who improved upon the

PATENT LAW REFORM 393

original patent to go to Holland and practise his improved
invention as a secret process than to practise it in this country
under the provisions of our patent law. To establish such
a state of things was obviously cutting at the root of
development. A few carefully disposed patents can, under such
a system, block the whole development of an industry against all
the world except only those privileged people who chance to be
the holders of the pioneer patents. It is a matter of no con-
sideration that these pioneer patents themselves may be perfectly
worthless for all practical purposes. It is their existence, not
their merit, which constitutes the strength of the patentee's
position.

This situation was clearly apprehended at a very early date in
the history of the chemical industry by our German competitors.
A system of blocking patents has been an organised industry
with the great German manufacturing chemists at least since the
year 1883 ; and when we hear of the large staffs which they keep
employed upon research work in their factories, it is well to
remember that, over and above those results of this laboratory
industry which take effect in improved processes and products,
there is a large output of novelties which are improvements only
in a legal sense ; the real value of which is that they eventuate
in patents of this blocking type which close the avenues of
improvement to other inventors.

It is impossible from any available data to ascertain to what
extent the British chemical industry has been sapped by means
of such mischievous patents, but this system of sapping has
been systematically and extensively developed, and it has had an
immense success.

In all these cases the cause of our weakness is the injunction.
It is to be understood that, according to the practice which
prevails to-day, a perpetual injunction is granted as a matter of
course to protect a patentee who has successfully established his
patent rights against an infringer.

Such being the mischief, we may now turn to consider what
are the remedies which Parliament has provided. The earliest
attempt Was embodied in a section (22) of the Patent Act of
1883, which provided a remedy which has come in recent years
to be well known under the style of a compulsory licence.

If this contrivance of a compulsory licence had been effective,
it would have met the whole difficulty. It would have prevented

394 THE BRITISH COAL-TAR INDUSTRY

the mischiefs which have arisen, and would probably have placed
the patent law of this realm in an entirely sound position. But
a very hard fate has pursued the reformers of our patent law.
This provision was still-born and never produced its intended
effect, a result which was due to faults of draftsmanship.
(A detailed discussion of the Patent Act 0/1883 follows here?)
The provisions of the Act of 1883 concerning compulsory
licences were never tested experimentally, for, although several
petitions were lodged and carried through to a conclusion, they
were all carried through under such unfavourable conditions that
anything more than an unsatisfactory success was rendered im-
possible. It is not surprising, therefore, that the agitation
already referred to for a reform of the Act of 1883 should have
gathered head and eventually should have prevailed in Parlia-
ment. In 1900 a Departmental Committee was appointed to
consider further remedial legislation, and in particular to advise
Parliament as to the adoption of the Continental provision of
the compulsory working within the realm of patented inventions.
The Committee reported against the compulsory working pro-
vision, and in favour of a reference of petitions for compulsory
licences to the High Court. The report contained also some
other suggestions, and in the ensuing year Parliament proceeded
to legislate on lines generally indicated by the Committee. In-
stead, however, of adopting the suggestion that petitions for
compulsory licences should go to the High Court, Parliament
took the extraordinary course of sending them for consideration
to the Privy Council. This expedient did not help matters at all.
The division of authority was still as marked and as mischievous
as when the petition was sent to a referee, and the practice of
the Privy Council tended rather to aggravate than to reduce the
costs incidental to the carrying of the petition through. So far
the last case was distinctly worse than the first, and in 1907
Parliament proceeded to deal with the matter for a third time.

The Act of 1907 was closely modelled upon the German
patent law. Accordingly a new remedy was introduced in the
shape of a condition making the working of a patented invention
within the realm compulsory, but the nature and measure of the
working to be required and the conditions which furnished an
excuse or imposed liability upon a patentee were left to be settled
by the judges in the administration of the law. It was probably
a wise expedient on the part of Parliament to leave these matters

PATENT LAW REFORM 395

thus in a plastic condition to be moulded and fixed by the action
of the judicature. The idea no doubt was that the obligation of
compulsory working would, on the one hand, discourage the
practice of taking patents for the purpose of blocking an industry,
and, on the other hand, would secure the development within the
realm of industries which are protected by patent right. The
Act has only been in operation for a period of about seven years,
and it is too soon perhaps to attempt anything like an estimate
upon historical foundations of its possible outcome. It may be
pointed out, however, that it has not had very much effect so far
upon the chemical industry. To those who have a practical
acquaintance with the conditions of the problem this will not be
surprising. The complications which it presents in its judicial
aspects are enormous. In part they may be illustrated by the
facts of the Levinstein case which have been described. In such
a case as that, for instance, where there was no market for the
goods which the patentee could manufacture and a large market
for the infringing goods which he did not know how to make,
what is the patentee's obligation under the law of compulsory
working ? Must he manufacture, to satisfy the law, a certain
quantity of unmerchantable goods, or is he to be held liable
to manufacture the improved goods whose production is the
infringer's secret ? The inherent difficulties are such that nothing
would be less surprising than that it should be found in the end
to be what it appears to have been in the beginning, an expedient
wholly ineffective for any useful purpose.

Such being the situation which has actually arisen, it will be
useful to consider the bearing of this situation upon the proposal
now made to establish, in competition with the German industry,
a self-sufficient industry in this country in the manufacture of
dyestuffs. We may take it for granted on this occasion that
no insuperable difficulty will arise. So far as research and
technical education are concerned there is not likely to be the
smallest difficulty about securing, and at once securing, the
necessary trained skill.

Let us assume that the works are started and in successful
operation. That fact will not make any difference to the subsist-
ing patent rights in this country of which, as is well known,
a very large proportion are held by foreigners and others whose
interest it is to favour the foreign competition with this domestic
industry. Now it is clear, therefore, that there will be a strong

396 THE BRITISH COAL-TAR INDUSTRY

disposition to repeat the Badische coup of 1883, and then, adopt-
ing the language of the judgment in that case, we may say that
notwithstanding " the great knowledge, great skill, and great
perseverance " which will be brought to bear in building up
these industries, the law will be invoked to say that the processes
so developed cannot be used in the production of the colouring
matters manufactured because the production of those colouring
matters is protected by patent rights. It may at once be admitted
that the new institution will be placed in a very different position
from that which was occupied by the defendant in the Badische
and Levinstein action. In the present case there is a possibility
of applying to the Board of Trade for a compulsory licence, and
if it were certain that such a proceeding would succeed it would
in substance remove the difficulty. There would still be an
important question of procedure to be considered, but that is
probably not of great importance. It cannot, however, be taken
for granted that an application for a compulsory licence would
succeed. The grounds on which such an application can be made
are strictly limited and, in fact, very narrow. If the patentee
himself takes adequate steps to supply the British market with
his patented goods, then, according to the interpretation adopted
by the courts of this provision of the statute, no order for a
compulsory licence can be made. Now, in the case at least of
important goods for which a large and profitable market exists,
there seems to be no conceivable reason why the foreign patentee
himself should not supply the demand. It is quite true that
he may be called upon to conduct his manufacture within the
realm, but he cannot be called upon, as matters stand, to grant
a licence to the new institution. He may prefer to remain an
active and privileged competitor with the new institution, and
so, although with diminished power of mischief, may still succeed
in casting his blight upon the undertaking. The carrying on of
the new industry under these conditions would seem likely to be
extremely fruitful of litigation, but by no means equally assured
of success ; for if it were possible to close any particular
manufacture down as the result of a successful patent action,
then it cannot be denied that nobody at the present moment
is in a position to say what precise field of industry will in the
end remain open to the proposed institution. This is the
difficulty with which the promoters are faced. The research
work of the laboratories of which we have lately heard so much

PATENT LAW REFORM 397

has resulted in an immense and extremely intricate network of
patents designed to protect, by their entanglement, the whole
field of chemical industry, which the Germans have made their
own. Hitherto these entrenched patents have afforded very
efficient protection partly, no doubt, because the defence of the
British industry has been left to the uncoordinated efforts of
British manufacturers, who have been attacked one at a time and
beaten in detail. It does not, of course, follow that it would be
equally successful against a fully organised effort to create a
British industry ; but, on the other hand, nobody can be justified
in asserting, as our patent law is understood and administered at
the present time, that such a large and organised institution
would have any better chance than the resolute manufacturer, like
the Levinstein Company in 1883, of making an effective stand
against the overwhelming brute force of a judicial injunction.

(An analysis of defects in the existing patent law, and suggestions
for their removal, follow here.}

Patent right is a privilege of such a character that it would
not be impaired for the purposes of beneficent operation by being
subject to a larger discretion in the exercise of the power of
suspension reserved to the Crown than is provided for in the
Patent Act. The objects of the grant are threefold :

1. The common good and benefit to the realm.

2. Reward and recompense for the industry, trouble, and
charges of the patentee.

3. The encouragement of other inventors in such laudable
and commendable labours as may tend to the good use and
service of the realm.

Now it is obvious, and may be taken to be generally admitted,
that such an absolutely unrestricted power of exclusive manu-
facture as was conceded in the Badische and Levinstein case
tends directly, not to promote, but to subvert the first of these
objects. It tends also to produce that just cause of grievance
which it was one of the declared objects of the Crown to avoid
in connection with the grant. Hence it may be said, with
confidence, that the relief by injunction which was granted in
the Levinstein case is subversive of the objects of the patent
grant itself. The practical question, therefore, is not whether
the power to restrain infringement by injunction shall be wholly
uncontrolled, but to what extent it should be controlled. The
obvious answer to this question is that it ought to be controlled

398 THE BRITISH COAL-TAR INDUSTRY

to such an extent as to secure all the objects of the grant ; includ-
ing the avoidance of any just cause of grievance. An answer
in those terms, however, is not very instructive, because the
practical difficulty is to discover those rules of practice which will
attain the end. One inference may, however, with confidence
be drawn even from this extremely indefinite statement of the
principle, and it is this : The injunction ought not to go as
mere matter of course, and without consideration of the cir-
cumstances of the case. A court, when granting an injunction,
ought to satisfy itself that the injunction will not cause the
inconveniences which followed in the Badische case, and, therefore,
something more than mere infringement ought to be established
to justify a court in granting a perpetual injunction.

The general principle with regard to injunctions was thus
stated by Lord Brougham :

" The principle which, as I humbly conceive, ought, generally
speaking, to be the guide of the court and to limit its discretion
in granting injunctions, at least where no very special circum-
stances occur, is that only such restraint shall be imposed as
may suffice to stop the mischief complained of." Blackmore v.
The Glamorganshire Canal Navigation, i Mylne and Keen, 185.

Coming to a narrower and, for our present purpose, more
pointed statement of the principle, we have it formulated by
Lord Lindley in the following terms :

" The very first principle of injunction law is that prima facie
you do not obtain injunctions to restrain actionable wrongs for
which damages are the proper remedy." London and Blackwall
Ry. v. Cross, Law Rep., 31 Chanc. Div., p. 369.

The careful observation of this salutary rule would obviously
preclude such mischievous results as we are now discussing,
and with such authority as it is possible to cite for the rule
one may without presumption speak of the existing and
mischievous practice as being a lapse from the sound doctrine
of the English law.

Let it be supposed, then, that by some means, either by
a voluntary recurrence on the part of the courts to Lord
Brougham's rule, or, failing that, by legislation, we were to
arrive at a satisfactory settlement of this practice, is there any
reason to think that the system would work badly and would
unfairly prejudice the rights of a patentee ? For the purpose
of discussing this question, I will assume that recourse is had

PATENT LAW REFORM 399

to Parliament, and that an enactment has been put upon the
statute book which goes in one particular beyond the older
practice of the Court of Chancery. I will assume, that is to say,
that the enactment provides in effect :

(1) That no perpetual injunction shall in any case be granted
to restrain infringement of a patent right, but only an injunction
to stand until further order ;

(2) That no injunction shall be granted to restrain infringe-
ment of a patent right unless it is proved to the satisfaction of
the court that the mischievous result to the patentee from the
infringement proved is such that he cannot obtain adequate
relief in respect thereof from the defendant charged with the
infringement.

What would be the result upon patent rights of such a
modification of the existing practice of the courts ?

(1) It would at once put an end to the blackmailing type
of patent action. In recent years a practice has grown up of
bringing patent actions against perfectly innocent infringers who
have no sufficient interest in the dispute to make an effective
defence. Now it is clear that if no injunction could be granted,
but only damages in a case of that sort, the patentee would find
that type of action a very unprofitable investment.

(2) Again, in a case such as the Badische action, it is clear
that the patentees would have been wholly unable to destroy
the British industry which they set themselves to attack. In
fact, it is probable that the result of that action would in such
a case have been more satisfactory to them as well as to the
defendant company than in fact it was. If they could not have
obtained an injunction they would have had to be content with
damages ; and although it may be presumed that in the circum-
stances of that case the damages would have been small, they
still would have amounted to something.

The proposal to establish a large manufacturing industry
under the existing conditions of the aniline-dye manufacture
is one which raises not only the commercial questions of
capitalisation and organisation, but also, in a very pressing form,
the comparatively dormant question of a reform of the patent
law. The comparative backwardness of our manufacture in
this line, easily as it is explained by those who allege the
indolence, supineness, and inaptitude for this class of industry
of the British manufacturer, can nevertheless be fully explained

400 THE BRITISH COAL-TAR INDUSTRY

only when the pitfalls of our patent law are also taken into
account. There is no doubt that both in 1852 and in 1883
substantial improvements were introduced into the administra-
tion of our patent law. That the Act of 1907 made for
improvement is open to much question. It complicated our
system by the introduction of incongruous elements, chiefly
from the German patent code, but it left untouched the mischiefs
which destroyed the British manufacture of aniline dyes, and laid
us open to misunderstanding and reprisal in foreign countries
without securing any countervailing advantage for our own
manufactures and manufacturers.

XXXI. : 1915

THE SUPPLY OF DYEWARES

BY PROFESSOR R. MELDOLA, D.Sc., LL.D., F.R.S.

(Abstract of Presidential Address to the Institute of Chemistry,
ist March 1915)

EARLY in August last year, as appeared from a question raised
in the House of Commons, it was foreseen that difficulties might
arise in this country, and that certain industries especially those
connected with textiles might be seriously affected through the
stoppage of supplies of chemical products, more particularly
dyestuffs, for which we were dependent to a preponderating
extent upon German factories.

I may be pardoned on the present occasion if I venture to
recall a warning which I sounded nearly thirty years ago. As
far back as 1886, I foresaw that the coal-tar colour industry as
conducted by us was doomed to decadence in this country. 1
Systematic inquiries made among the consumers revealed the
fact that even at that time 90 per cent, of the dyestuffs then in
use here were of foreign manufacture. The voluminous news-
paper correspondence which has been going on in connection
with this subject all over the country during the last few months
shows that, in military parlance, no lost ground has been regained
before the outbreak of the war we were still importing nine-tenths
of our colouring matters from Germany and Switzerland. Since
1886, on every suitable occasion, I have been endeavouring
to instil into the public mind the lesson that the development
of this industry abroad has been due to the recognition and
utilisation by manufacturers of the results of chemical research.
To me, therefore, the crisis threatening our textile industries is
no matter for surprise it appears simply as a relationship of

1 See Meldola, Jour. Soc. Arts, 1886. See p. 121, ante.

401 26

402 THE BRITISH COAL-TAR INDUSTRY

effect to cause. It is generally supposed that the prophet who,
justified by events, is enabled to say " I told you so," is privileged
to regard himself with the greatest complacency. In the present
case, the only feeling I am able to express is one of humiliation :
it is absolutely painful that under the stress of circumstances
our weakness should have been laid bare to all the nations a
weakness for which there can be found no justification in the
plea that no alarm had been raised or that the supply of chemical
talent in this country was inadequate.

The President of the Board of Trade appointed early in
August a committee for the purpose of advising the Government
with respect to the means of meeting the national requirements,
with the Lord Chancellor, Viscount Haldane, as chairman. From
this main committee there was subsequently formed a sub-com-
mittee for dealing especially with the manufacture of dyestuffs,
under the chairmanship of Lord Moulton, whose extensive
experience in matters connected with this branch of applied
chemistry is well known.

It is now public knowledge that a scheme formulated by
the Government in consultation with a committee representa-
tive of the great dye-using organisations was put forward at the
close of last year, and after full discussion by those immediately
concerned was finally referred back for modification. This is
not the occasion for entering into a detailed analysis of the
various grounds on which the scheme was considered unsatis-
factory, but the Government has determined as I think, wisely
not to allow the project to fall through, and has now launched
a new scheme which differs from the first in certain important
particulars. Whether this new scheme will materialise remains
to be seen : so far, all that can be said is that a considerable
number of the dye-consuming companies appear to be favourably
disposed towards it. It would be out of place here to attempt
to explain or to criticise the scheme as it stands, but I want it
to be clearly understood, as there has been much public mis-
apprehension on this point, that for neither of these schemes is
the Board of Trade Advisory Committee or the Dyestuffs Sub-
Committee in any way responsible. The grounds on which it
was considered that public action was imperatively called for
were set forth most clearly in an address delivered by Lord
Moulton at Manchester, on 8th December of last year, 1 and in

1 See p. 351, ante.

THE SUPPLY OF DYEWARES 403

that address he stated explicitly that he only held himself re-
sponsible for the advice that the Government should take action,
but not for the particular shape or form which that action should
assume. Out of the present situation, therefore, there arise
certain general considerations which the chemical profession will
do well to take note of, and for this reason I will venture to
direct your attention to some of them.

In the first place, stating the case baldly, and in the broadest
possible terms, the principle is adopted that there should be
established a company in which the consumers should be the
chief shareholders, and which the Government should subsidise
by advancing capital at a certain rate of interest to the extent
of i, 000,000. It is unnecessary to go into details, but it will
be seen that the scheme is in a way a co-operative one and that,
for the first time, we have a distinct proposal in this country for
the establishment of a State-aided industry. It is beyond our
province to discuss this proposal in its economic or political
bearings. In view of the great interests at stake, the policy
appears to me to be a sound one, as was admitted by both
political parties when the proposal was mentioned in the House
of Commons last November by the President of the Board of
Trade (Times report, 28th November 1914). What concerns
us most as representatives of the chemical profession is that our
aspect of this great industry should be kept well to the fore in
the present scheme, or in any other scheme that may hereafter
be put forward.

In the next place, I take it for granted that we all desire to
see the restoration of the coal-tar colour industry to this country,
and, be it noted, not only restored, but permanently retained
after the war. Now, the discussions of the Government schemes
in various parts of the country by dye-consuming organisations,
Chambers of Commerce, and so forth, have all centred round
political or economic questions ; that which is to us the vital
principle, viz. adequate chemical control, has been subordinated
or left out of consideration altogether. It is the old, old story
we wrangle over the question as to the method by which the
industry shall be established and maintained here, whether by
Free Trade or Protection, or Subvention or by any other device,
and we leave out of consideration the question whether a few
years hence there will be anything in the way of dyestuffs worth
protecting ; whether there will be a sufficient basis of material

404 THE BRITISH COAL-TAR INDUSTRY

products left for the politicians and economists and business
people to wrangle over. It is not a purely business problem
which the Government has undertaken to solve ; it is primarily
a chemical problem. It is not even a business problem in the
ordinary trade sense, because the main object is at first to supply
our own wants, and the chief consumers are to be the chief pro-
ducers. The question of business in the sense of export trade
is at present remote.

The conditions which have to be met if we wish to see this
country once more the home of the colour industry may be
well known to us here, but are certainly imperfectly understood
by the public. Even those most concerned those who are
invited to subscribe the capital appear in most cases to have
an idea that all that is necessary is to find the money, secure
the Government aid, appoint a board of business directors, and
lo ! the industry will forthwith spring into existence ready to
cope with all emergencies. Now, what are the facts of the
case ? About five hundred different dyestuffs of definite com-
positions have been given to tinctorial industry as the products
of chemical research. Of these, a certain number only can be and
are being made in this country, the total output of our factories
being at present inadequate for the requirements of our textile
industries. The first step to be taken, therefore, is to enlarge
and develop our existing factories so that the dyes which can
be made here should be turned out in larger quantities. This
necessity has, of course, been provided for in the Government
scheme, and so far so good. Moreover, if the extension of
the existing factories still leaves us with insufficient supplies,
new factories must be erected and equipped. That also is pro-
vided for in the scheme ; but if we want to establish the
industry here permanently we must look beyond all this where
shall we be left after the war ? We shall be in possession of
processes for making a certain number of dyes, and the supply
of this particular set of products may possibly be sufficient for
the particular purposes for which they are required. Let us
label these provisionally " staple products." But there will still
be an outstanding number probably a majority of other pro-
ducts which we have never yet made here, and for the working
out of these processes no combination of " business " talent is
of the slightest value. I repeat, it is not a business question,
but a chemical question, and it is by chemkal research alone that

THE SUPPLY OF DYEWARES 405

our colour industry can be saved in the long run. Consider the
leeway that we have to make up. The German colour industry
has been built up by the utilisation of the results of research
carried on in the factories and universities and technical schools
for a period of over forty years ! To suppose that we can
retrieve our position after forty years of neglect by starting a
company the directorate of which is to consist solely of business
people is simply ludicrous. It was against this principle that I
ventured to raise my voice in the Times of 2Oth January last, and
I am extremely glad to find that not only the chemical and
technical worlds, but the large and representative body of dye
users and producers which form the Dyewares Supply Enquiry
Committee of the Society of Dyers and Colourists, fully endorse
this view and have forwarded to the Board of Trade a resolution,
passed at Manchester last month, in support thereof. A meeting
of the Federation of the Light Leather Trades held at the
Leathersellers' Hall on 22nd February passed a similar resolution.
It is satisfactory to learn that there are at any rate some of the
dye-consuming organisations which have grasped the situation
scientifically. To imagine that a dyer, however skilful he may
be, is, by virtue of his occupation, necessarily competent to
direct the affairs of a company which is concerned with the
manufacture of the dyes which he uses, is about as sensible as
the assumption that a person who can tell the time by his watch
is thereby qualified to undertake the direction of a factory for
the construction of chronometers.

One feature of the new scheme which the chemical profession
will view with favour is the distinct recognition of research as a
necessity for the development of the industry. The Government
"will, for ten years, grant not more than 100,000 for ex-
perimental and laboratory work." That, although an inadequate
endowment, is certainly a concession which marks an advance in
official opinion for which we are grateful. It will be for the
satirist of the future to point out that it required a European
war of unparalleled magnitude to bring about this official recog-
nition of the bearing of science upon industry. It would be
but a truism to state here the purposes for which research is
required ; the question we have to raise is Who is to direct
this research ? A directorate of purely business people would
certainly be incompetent ; a board composed of dye users could
do no more than indicate what dyestuffs were needed. True, it

406 THE BRITISH COAL-TAR INDUSTRY

is proposed that the company should take powers to secure the
assistance of a committee of experts, but this appears to me to
be simply a reversion to that policy of " drift " which I have
for so long been struggling to overthrow. The experts are, as
usual in this country, subordinated ; their assistance is to be
invoked at the discretion of a board the members of which can
have no real knowledge of the conditions necessary for producing
the materials they require now still less would they be com-
petent to point out dangers ahead. The "staple products"
upon which they are asked to stake their capital may a few years
hence be superseded by the products of subsequent discovery.
The policy of attempting to run a highly specialised and rapidly
developing branch of organic chemical industry by a company
of business people, with expert assistance when required, is fatal
if we want to establish the industry permanently here. The
group of industries which have arisen from the products of the
tar-still are not going to remain stagnant after the war, and it
is scientific guidance and not mere assistance that will keep them
alive. It is the expert, and the expert only, who can foresee
the course of development, who can keep in touch with the
progress of research, and who can direct with intelligence the
campaign against our competitors. If such scientific direction is
withheld, all schemes are sooner or later bound to end in failure.

XXXII.: 1915

THE POSITION OF THE ORGANIC
CHEMICAL INDUSTRY

BY PROFESSOR W. H. PERKIN, F.R.S.

(Presidential Address delivered to the Chemical Society, 25th March 1915 :
Journal of the Chemical Society, 1915, p. 557)

THE subject which 1 have chosen for my address on this occasion
must always be regarded as of the highest importance, not only
to this Society, but also to the country at large, because of its
intimate connection with the prosperity of so many of our largest
and most successful industries. It is a subject which has been
discussed over and over again at scientific societies, in scientific
journals, and particularly in the newspapers by chemists, manu-
facturers, politicians, and the general public. In his valuable
presidential address to this Society in 1907, entitled "The
Position and Prospects of Chemical Research in Great Britain,"
Professor Meldola had much to say about the bearing of research
on the position of industry ; and in 1909 the same writer dis-
cussed very fully the question of the value of education and
research in connection with applied chemistry in his presidential
address to the Society of Chemical Industry. It would therefore
seem scarcely necessary that I should take up your time by
bringing these matters to your notice again. I do not propose,
however, to apologise, partly because I am of the opinion that a
summary of the position of the organic chemical industry in as
few words as possible will not be out of place and may be useful,
but more particularly because, in spite of the large amount of
literature bearing on the subject, I feel convinced that the causes
of the decadence of this industry in this country are still imper-
fectly understood.

407

4 o8 THE BRITISH COAL-TAR INDUSTRY

The seriousness of the position is readily grasped when it is
borne in mind that the value of the colouring matters consumed
in this country is at least 2,000,000 per annum, and that more
than 90 per cent, of this quantity comes from Germany ; and,
when it is remembered that these dyes are essential to textile
industries representing at least 200,000,000 per annum, and
employing more than 1,500,000 workers, it is easy to see to
what an alarming extent these great industries are in the grip
and power of the Germans. There are, of course, many other
industries which depend on colouring matters for their existence,
such as, for example, the wallpaper, the printing, and paint
industries, to all of which lakes and pigments are absolutely
essential, and of late years almost the whole of these have been
imported from Germany. Again, the enormous quantities of
organic chemicals required for photographic purposes such as,
for example, pyrogallic acid, hydroquinone, metol, and many
other similar developers, the natural and artificial products
employed in such huge quantities in the manufacture of scents
and perfumes, the synthetical and other drugs which have in
some ways revolutionised medical science, and also many of the
more important disinfectants, have been almost exclusively made
in Germany. We may add to this list the vast trade in fine
chemicals, for here we are again completely outclassed, since
there are no firms in this country which can compete with
Kahlbaum, Merck, Schering, de Haen, and a host of others
either in the range or the purity of their products, and it has
long been our habit to import almost all our organic fine
chemicals from Germany. It may indeed be said that Germany
has no competitor worth considering in the whole domain of
organic chemical industry. That we should have allowed trades
of such magnitude to pass almost completely into the hands of
a foreign nation seems incredible, and, as the inevitable result,
we are face to face with the serious position that, the foreign
supply having stopped, stocks are rapidly vanishing and prices
are rising to such an impossible level that the progress of several
of our industries is greatly hampered. Indigo, perhaps the
most essential of all dyes, is manufactured entirely by the great
German colour works, and the stock in this country a few weeks
ago was so low that the price rose to at least ten times what it
was before the war ; the same thing is happening in other cases,
and many dyes cannot be obtained at any price. Obviously we

THE ORGANIC CHEMICAL INDUSTRY 409

must take warning, and not allow, in the future, our textile and
so many other similar industries to be controlled in this way
by the foreigner, and to be in danger of being brought to a
standstill.

How are we to explain the fact that we have allowed some
of our most important industries to get into this critical condition,
and what do we propose to do to remedy this state of things
and prevent any recurrence in the future ? No one doubts for
a moment that the wonderful opportunity of establishing a great
national industry, due to the discovery of the aniline dyes in
this country, has been allowed to escape us, and various reasons
have been put forward to explain the loss of the colour industry.
There can be no doubt that a good many different causes have
been at work. One of the main reasons for our position is that
we as a nation, and our manufacturers in particular, have failed
to understand the extreme complexity of the scientific basis of
organic chemical industry, and have concluded that this industry
could be carried on much in the same way as the manufacture
of sulphuric acid, caustic soda, and other heavy chemicals. The
manufacturer has always been unwilling to acknowledge that
neglect of science in his works is the real cause of his failure to
retain the colour industry in this country, and has therefore put
forward all sorts of other reasons to explain his want of success.

Thus it has been urged repeatedly that our patent laws were
greatly to blame, and that these laws were such that an English
patent was no protection, and that so soon as anything new had
been discovered in this country the Germans at once set to work
to manufacture it.

Even if this were true and there may be some truth in it
it does not explain why the Germans were able to obtain their
raw material as they did in this country, to transport it to Ger-
many, and then to send the dye over here, and at the same time
to make a handsome profit out of the transaction. Again, it has
been urged that the obstacles to the use of pure alcohol which
existed at the end of the last century played a great part in
bringing about the decadence of the coal-tar colour industry in
this country. Possibly there has been some hardship in special
cases, but a Departmental Committee of the Board of Trade took
evidence from a large number of experts in this country and in
Germany, and issued a report on " Industrial Alcohol" in 1905,
and the Committee arrived at the conclusion that, as a statement

4 io THE BRITISH COAL-TAR INDUSTRY

of historical fact, the assertion that the coal-tar industry has been
lost to this country on account of obstacles to the use of pure
alcohol is devoid of substantial foundation. 1 Of late years the
restrictions on the use of duty-free alcohol have been so relaxed
and the denaturants which may be employed are of such a wide
range, including as they do the actual articles to be manufac-
tured, 2 that there is probably at the present time less difficulty
put in the way of the manufacturer here than is the case in
Germany.

It is quite obvious that other reasons than those I have just
mentioned must be found to account for the gradual transference
of the coal-tar industry to Germany. The decadence of this
industry and its gradual transference to Germany may be said to
have begun during the period 1870-75. It was in 1874 that
the works of Perkin & Sons at Greenford Green was sold to the
firm of Brooke, Simpson & Spiller, and these works were then
in the most prosperous condition, and much in advance of any-
thing that existed in Germany.

One reason for the sale was my father's natural dislike to an
industrial career, and his desire to devote himself entirely to
pure chemistry. There was, however, a much more weighty
consideration which played the really important part in his
decision to dispose of the works.

It was recognised and, as the subsequent history of the coal-
tar industry has shown, correctly recognised that the works
could not be carried on successfully in competition with the rising
industry in Germany unless a number of first-rate chemists could
be obtained and employed in developing the existing processes,
and more particularly in the all-important work of making new
discoveries. I remember quite well that inquiries were made at
many of the British universities in the hope of discovering young
men trained in the methods of organic chemistry, but in vain.
There cannot be any doubt that the manufacturer of organic
colouring matters during the critical years 1870-80 was, owing
to the neglect of organic chemistry by our universities, placed in
a very difficult and practically impossible position. At that time
organic chemistry was not recognised by the older universities,

1 See p. 228, ante.

2 For example, the manufacturer of pure ether may denature the alcohol
he uses by the addition of a little sulphuric acid, and, in the case of diethyl-
aniline, this substance or aniline may be used as the denaturant, and so on.

THE ORGANIC CHEMICAL INDUSTRY 411

and the newer universities, which have since done so much for
the progress of science, had not come into existence. It is surely
remarkable that the study of so important a subject as organic
chemistry should not only have been practically ignored by our
universities in the past, but that even at the present day it does
not flourish in the way it does in almost every university and
technical school in Germany.

This seems to me the more remarkable when it is borne in
mind that all problems connected with life, either in the animal
or vegetable kingdom, are essentially problems which depend on,
and are largely controlled by, organic chemistry, and it is there-
fore clear that little progress can be made towards the solution of
such problems until the processes of organic chemistry are clearly
understood. Quite apart, therefore, from its industrial aspect,
organic chemistry must, from the purely scientific point of view,
always be regarded as a branch of science of the very highest
interest and importance.

If the record of our universities is examined, it is at once
obvious that many of these famous places, and more particularly
the universities of Oxford and Cambridge and the Scottish
universities, contributed practically nothing to the advancement
of organic chemistry during the latter part of the last century,
and their output of research in this subject is still far less than it
ought to be. It is difficult to understand why our universities
should so persistently hold aloof from progress, and should so
often entirely fail to gauge the importance of leading the way in
new developments, on which, after all, in many cases the welfare
of the country depends. How very different is the picture
exhibited by the attitude of the German universities towards
organic chemistry during the critical period I have mentioned !

So soon as the importance of organic chemistry became
apparent, great teachers, such as Liebig and Wohler, Kekul6
and Baeyer, founded schools specially devoted to the subject,
and they and their pupils then began to publish that wonderful
series of classical investigations which laid the foundations on
which the superstructure has since been raised.

The value of the example of these great teachers and of the
system of research which they had initiated soon became generally
appreciated by the universities in Germany, and every effort was
made, bv the establishment of laboratories supported by adequate
grants from the various States, to help forward the new move-

4 i2 THE BRITISH COAL-TAR INDUSTRY

ment. The step which, in my opinion, did more than anything
else to bring about the wonderful development of organic
chemistry in Germany was the provision that research must be
an essential part in the training of every German student of
chemistry.

In almost every direction, and to a far greater extent than has
been the case in any other country, Germany has recognised the
value of the closest possible contact between the industries and
the universities. In Germany the majority of the Professors and
Privatdocenten are in close touch with the large factories, and
spend part of their time in solving technical problems which they
either devise themselves or which may be submitted to them by
the manufacturer.

I have it on the authority of several of the best-known
directors of German works that the atmosphere of the university
laboratory is much more suitable for discovery than that of the
works, and that, as a fact, many of the most valuable discoveries
which subsequently proved to be of the highest technical im-
portance have been made in university laboratories and transferred
to the works as the result of the intimate connection I have just
described. Moreover, when it is remembered that the important
dyes, malachite green, the phthaleins, artificial alizarin, and in-
digo, and the pharmaceutical products antifebrin and antipyrine,
to mention only a very few cases, were discovered in university
chemical laboratories, it is quite clear that there is much truth
in the statement of the works directors. Close association of
the universities with the industries does not exist to any extent
in this country, and is one of the things we have to aim at in
the future, however distasteful this may appear to some of our
academic circles. Systems of training and methods of teaching
which may have been useful centuries ago, but have become
antiquated, must, in these days of acute competition, give place
to methods that are more in accordance with existing requirements
and the practice of other nations ; otherwise we are bound to
fall behind in the race.

It must, I take it, be assumed that the aim of the university
is to acquire the best scientific ability for its professoriate and
teaching staff, and therefore the home of the best scientific re-
search talent must always be the university laboratory ; it is there-
fore quite clear that close association between these laboratories
and the works must be of great advantage to industry. Such a

THE ORGANIC CHEMICAL INDUSTRY 413

connection cannot fail to be of great value also to the university,
for it must result in the manufacturer taking a keen interest in
the welfare of the department with which he is associated ; he
will willingly provide material from his works for teaching and
research, and subscribe liberally to the resources of the depart-
ment, and no scientific laboratory chemical, physical, or
engineering can do good work unless it is liberally supplied
with material and funds.

It has often been suggested to me that a professor who is
engaged in solving problems of a technical nature will have no
time for other scientific research work, and that, since results of
technical value must often be kept secret and may never be
published, the reputation of his department will suffer. Ex-
perience shows, however, that such is not the case, for there
is little, if any, diminution in the output of research work in
pure science from the German laboratories as the result of this
system.

We must, I think, agree that one of the main reasons for the
rise and development of the German chemical works is the
appreciation on the part of the manufacturer of the value of
science in connection with industry, and the recognition of the
great importance of a close alliance between the works and the
research laboratories of the universities and leading technical
institutions of the country.

My view is that contact with the research department of a
large works must always be stimulating ; problems are en-
countered, many of them of great scientific interest, which would
never suggest themselves in strictly academic circumstances ; and
as one of the results, the tendency, which is always present under
existing university conditions, for the professor to become an
academic fossil and unproductive is postponed. Again, we are
all aware how difficult it often is to find suitable research subjects
for the budding chemists under our charge, and contact with the
research departments of a flourishing works cannot fail to suggest
subjects for investigation which are eminently suitable to occupy
the attention of young men, many of whom will ultimately take
up technical work. I look forward to the time when the scientific
staffs of our universities and technical schools will not only be
available for industrial research, but will be encouraged by those
in authority to undertake such work ; for 1 am quite certain,
and indeed it is very generally admitted, that the association

4H THE BRITISH COAL-TAR INDUSTRY

of the best academical talent in the country with the technical
laboratories of the works can only be of the highest mutual
benefit.

After all, this kind of thing is quite common in the case of
the engineering departments of our universities and technical
schools ; and if the system works well in the case of engineering,
there is surely no reason why it should not be equally successful
in the case of chemistry.

Our competitors have, from time to time, given their opinion
as to the reasons for the transference of the organic chemical
industry from this country to Germany, and, as such views
cannot fail to be instructive, it will not be out of place if I quote
one such utterance. On the occasion of the jubilee or the
discovery of mauve, in 1905, Dr Duisberg, one of the best-
known directors of the colour works of Bayer & Co., in Elberfeld,
went fully into this question, and I propose to read a few extracts
from his remarks which have a special bearing on this matter.
Dr Duisberg said : " You inquire further, and wish to know
how it is that the German soil, in which the coal-tar colour
industry has grown so powerful, varies from English soil ; what
particular conditions were there which had been so advantageous
for its fructification ; whether it was not eventually possible to
produce artificially the same conditions also in England, and
that here also in the land of its birth those rich and golden fruits
could not be gathered, the harvest of which is reaped by Germany
year by year. I do not believe in such acclimatisation in England,
at least for the present. No other industry requires so much
uniformity of thought and action, science and practice, as organic
chemistry and the organic chemical industry.

"In Germany, not only has chemical science developed to a
considerable extent, but at the same time the technique of organic
chemistry has flourished. Both have stimulated and vitalised
each other, and both have supported each other. Such was not
the case in England. Although the Englishman is in general
practical, he is wanting in that peculiar quality which we
Germans are remarkable for that is, not perseverance, but
patience and the power of waiting for success. For all the
Englishman does he expects soon to be compensated in hard
cash."

Continuing, Dr Duisberg used the following words, which
are particularly interesting in view of the present crisis : "But

THE ORGANIC CHEMICAL INDUSTRY 415

you will say, when the problems have been solved, and when the
patents have run out and the manufacture is free to everyone,
c Why should not the English and foreign works decide to cope
with the German firms and compete against them ? '

"In my opinion this would be futile, and would be of no
avail. Even in Germany, where, as we have seen, the conditions
are the most favourable, it would now be scarcely possible, or
at least be a singular coincidence if a manufacturer, although
possessed of energy and capital, should succeed in building up a
new firm in the colour line so as successfully to compete against
the existing powerful works. Whereas, therefore, the conditions
in England for many industries, such as for the mining industry,
for spinning and weaving, not forgetting inorganic chemistry, are
far more advantageous than in Germany, the latter country has
the natural privilege in the organic chemical industry, and other
nations should not envy her in this, but leave it to her."

It is because we have acted in the manner recommended by
Dr Duisberg, and have left the coal-tar colour industry to
Germany, that we find ourselves in the present grave and serious
position.

Views similar to those of Dr Duisberg have been expressed
in many quarters, and Lord Moulton, speaking at the Royal
Society of Arts on 3rd December of last year, gives an example
which is also very much to the point. 1 " I read," he said, " the
other day with bitter feelings the address of one of the ablest
industrial chemists in the world the head of one of the German
chemical industries who, talking about this very subject, said :
' England talks not only of holding her own in the war, but of
beating us in the chemical industry. She cannot do it, because
the nation is incapable of the moral effort of taking up such an
industry, which implies study, concentration, patience, and fixing
the eye on distant consequences, and not merely on the monetary
result.' ' Lord Moulton himself puts the matter in this way :
" Some fifty years ago organic chemistry opened up a domain of
industrial wealth that he could only compare to that opened up
by the discovery of steam power. He had been able to come to
but one conclusion that, either from being too well off, or from
sluggishness of intellect, or from the fact that the capital of the
country had passed into the hands of people who were unwilling
either to learn or to think, England had abstained almost entirely

1 See p. 347, ante.

4 i 6 THE BRITISH COAL-TAR INDUSTRY

from an attempt to reap the rich harvest open to the industrial
world by the advance of organic chemistry." In his address
delivered in the Town Hall, Manchester, on 8th December 1914,
Lord Moulton said : " Gentlemen, we have to look the truth in
the face. It (the loss of the coal-tar colour industry) was for no
other reason than that the English dislike study. The English-
man is excellent in making the best of the means at his disposal,
but he is almost hopeless in one thing. He will not prepare
himself by intellectual work for the task that he has to do. Now
there is the cause and, so far as is material, the sole cause of the
German supremacy. Is that a cause which must permanently
operate ? The answer is, of course, ' No.' But it is for us to
reform ourselves ; otherwise no relief can come." *

I have ventured to read these short extracts because they
contain the gist of the matter, and because I cannot think of any
words which might describe the position better.

If, then, we accept the enormous technical importance of
organic chemistry, and recognise, as Lord Moulton puts it, that
the industry is so vast that it can only be compared with that
opened up by the discovery of steam power, and if we decide
that we are not going to allow as Dr Duisberg suggests that we
should all this wealth and prosperity to pass entirely into the
hands of a foreign country, what course must our manufacturers
adopt in order to get a share of this ? I have already said, and
everyone will agree, that they must, in the first place, make up
their minds so to conduct their works that research is going on
unceasingly ; no works can possibly flourish which is content to
manufacture only well-known colours, and it is only by the dis-
covery of new colours and other products that manufacturers can
hope to get a satisfactory return on their capital. The manu-
facturer must therefore see that his laboratories are properly
equipped, and well supplied with research chemists of ability,
who have had a sound scientific training, and also some ex-
perience in the methods of research. All this, however, will
avail little unless he has a scientific leader in his works who is
able to direct the investigations of his young staff in the right
channels.

Students of mine who have entered chemical works have
frequently complained to me that there is no one over them
qualified to direct their investigations, and that original work

1 See p. 351, ante.

THE ORGANIC CHEMICAL INDUSTRY 417

seems to be considered of secondary importance, and only to be
indulged in when there is nothing else in the works to occupy
the attention of the chemist.

So far as I am aware, there is not a single colour works in
this country which has a really brilliant scientific head by which
I mean a chemist of wide scientific experience, and with the
knowledge and ability to direct research ; and this is a very
serious state of things, and quite incompatible with chemical
efficiency.

I have long thought that the want of an able scientific head is
one of the most obvious reasons why our colour works are in such
an unsatisfactory condition. The success of a business based on
science must often be essentially the work of a single brilliant
scientific man, just as the success of a great school rests with the
headmaster, and the reputation of a university laboratory depends
on the ability of the professor.

If a works is fortunate enough to have the services of a
distinguished scientific man, capable of initiating and carrying
out original investigations, and who will not only be constantly
making discoveries himself, but be able at the same time so to
influence his young staff that they will follow in his footsteps,
the success of such a works can never be in doubt. I am afraid,
however, that it will be a long time before we can hope that our
manufacturers will give up their old-fashioned rule-of-thumb
methods and fully grasp the truth of this vital matter.

My experience of the manufacturer in this country is that he
is usually merely a commercial person who does not like the
expert, and especially the idea of giving the expert a prominent
position in the control of his works. Possibly the reason in
many cases is ignorance of the value of science, but more prob-
ably it is due to the fact that, being ignorant of science himself,
he feels that if the expert is given too much prominence he
must either study himself in order to understand the expert or
leave the essential control of the business in his hands. Both
these courses are distasteful to the ordinary commercial member
of a board of directors ; the expert is therefore relegated to the
background, and the business comes to grief.

It would seem to be scarcely necessary to point out that, if
a chemical works is to be successful, the first essential is that it
must be under chemical control, and that every department must
be in the hands of an expert ; the board of directors may then

4 i 8 THE BRITISH COAL-TAR INDUSTRY

be a mixed board, provided that steps are taken to ensure that
chemical opinion is largely represented on it. The recognition
of the soundness of this principle is one of the main reasons for
the success of the German works.

Anyone who has had the opportunity of visiting the principal
German colour works, as I have, cannot fail to have noticed that
chemical control is everywhere ; the heads of departments are
always chemists, and the board of management invariably includes
a large proportion of the abler chemical experts employed in the
works. Not only do German business men understand that the
control of a chemical works must be in the hands of the chemist,
but they are also careful to remunerate their chemists liberally
and to give them a share in any new development they may
initiate, with the result that many of their leading chemists are
in receipt of salaries quite unheard of in this country.

When we ask the question whether we can adopt methods
of a similar kind in this country we find ourselves at once face
to face with very grave difficulties. Let us assume that the
necessity for the chemical control of a chemical works is conceded,
as conceded it must be, and that it is clearly understood that the
next step is the discovery of improvements in every direction,
such as the invention of dyes better than those already known,
and the economical development of essential existing processes,
then the first thing to be done will be for our universities to set
to work to educate a supply of organic research chemists who
will be able to undertake this work. This will mean that
organic chemistry will have to flourish to a much greater extent
than it does now, because the supply of organic research chemists
available under ordinary conditions is a very small one, and
scarcely sufficient to meet even the moderate demand which exists
at the present time.

If the effort gradually to develop it is not a question of
immediately establishing a thriving organic chemical industry
in this country is to be seriously taken in hand, and not to be
merely talked about, and if the requisite capital is forthcoming,
it is obvious that what will be required before everything else will
be a really able chemical staff, and there should, therefore, be a
great opening in the near future for young organic chemists of
ability. It is unfortunate from this point of view that many,
probably the large majority, of our young chemists are not
immediately available, since most of them are at present engaged

THE ORGANIC CHEMICAL INDUSTRY 419

in military service, and therefore the evolution of an efficient
chemical staff will be no easy matter. A small beginning may
have to be made, but, if the manufacturer will continually bear
in mind that chemical efficiency must always be the basis of all
his calculations, there is no reason to doubt that success will
come in the end, even though it may, and probably will, be very
slow at first.

Soon after the outbreak of the war, the critical position brought
about by the shortage of the dyes which are vital to both the
cotton and wool trades, and the impossibility of importing further
supplies from abroad, called for immediate attention. Urgent
representations from dyers and calico-printers and others engaged
in trades which require large supplies of dyes, forced the Govern-
ment to see that something must be done, and done as quickly
as possible, to find a solution for the extraordinary situation that
had arisen. A Board of Trade Committee was therefore appointed
on 25th August, with the Lord High Chancellor (Viscount
Haldane) as chairman, 1 with instructions to consider the best
means of obtaining for the use of British industry sufficient
supplies of chemical products, and, after hearing the evidence
of many of the more important producers and consumers, a small
committee, of which Professors Meldola and Green and I were
members, was charged with the task of sifting the mass of evi-
dence which had come forward from all quarters.

The chairman of this sub-committee Lord Moulton
devoted a great amount of his time and energy and experience
of German industrial conditions to the task of interviewing repre-
sentatives of the industries which were affected by the stoppage
of supplies from Germany, and, as the result of the report of the
sub-committee to the larger body, a meeting of representatives
of industrial firms and associations was held on loth December
at the Board of Trade, when the following resolution was passed
unanimously : " That this meeting approves in principle of a
national effort being made by the trade to increase the British

1 The other members of the committee were Mr John Anderson, Dr George
Thomas Beilby, F.R.S., Prof. James Johnston Dobbie, F.R.S., Mr David
Howard, Mr Ivan Levinstein, Prof. Raphael Meldola, F.R.S., Mr Max
Muspratt, Prof. William Henry Perkin, F.R.S., Mr Milton S. Sharp, Sir Arthur
J. Tedder, Mr Joseph Turner, and Mr Thomas Tyrer, with Mr Frank Gossling,
B.Sc., as secretary. Prof. Arthur George Green, M.Sc., was subsequently
added to the committee.

420 THE BRITISH COAL-TAR INDUSTRY

supply of synthetic colours, and welcomes the assistance of His
Majesty's Government for that purpose." A committee 1 was
appointed, and shortly afterwards recommended a scheme which
involved the formation of a joint-stock company, having for its
object the manufacture and supply of synthetic colours. Subse-
quently the Government announced that they were prepared to
assist such an effort in the following way : " If a limited Company
were formed on co-operative lines with a share capital of
3,000,000, the Government agree to advance to such Company
1,500,000, bearing interest at the rate of 4 per cent, per annum,
and secured as a first charge on the assets and undertaking of
the Company, and to be repayable in twenty-five years." The
important proviso was, however, made that " the interest on the
advance and a sinking fund for the repayment are to be payable
only out of the net profits of the Company, but are to be cumu-
lative." When this scheme was made public its reception was
not cordial, and the application for shares fell far short of what
had evidently been expected by its promoters. In explanation
of this it should, in the first place, be quite clearly pointed out
that neither the Board of Trade Committee nor the sub-com-
mittee had anything whatever to do with the preparation of the
scheme, and it is certainly extraordinary that a committee
consisting entirely of business men, and which did not include
a single chemical expert, should have been entrusted with the
formulation of a scheme for the founding and developing of a
chemical industry. 2

Had a chemical expert been present I venture to think that
such a scheme would never have been placed before the public.
It is stated in the memorandum of agreement attached to the
scheme that the Company had been incorporated for the purpose,
among other things, of manufacturing and selling dyes, colours,
and other chemical substances, which, previously to the war,
were exclusively or principally manufactured in Germany, and
no mention is made of what ought to be the main object of such
a Company, namely, the employment of a large staff of research

1 The committee appointed was Messrs Lennox Lee (Calico-Printers'
Association), Milton S. Sharp (Bradford Dyers' Association), H. W. Christie
(United Turkey-Red Company), Chas. Diamond (English Sewing-Cotton
Company), G. Marchetti (John Crossley & Sons), and R. D. Pullar (J.
Pullar & Sons).

2 Compare Prof. Meldola's admirable letter in the Times of loth January.

THE ORGANIC CHEMICAL INDUSTRY 421

chemists under leaders of ability for the purpose of making new
discoveries in every possible direction.

It cannot be too strongly emphasised that it is not merely a
question of producing the dyes which are required during the
war ; any company which is formed must be established in so
strong a position that it can expect to deal successfully with the
keen competition which will be waged with the greatest severity
by the Germans after the war.

The promoters of the scheme do not appear to have appreciated
the difficulties of the situation, and obviously think that the
manufacture of dyes in this country which previous to the war
had been invented and produced in Germany is a matter which
can quite easily be managed.

It seems to be imagined in many quarters that, in order to
manufacture a dye which had previously been made in Germany,
all that is necessary is to follow the directions given in the patent
dealing with that particular dye. No greater mistake could
possibly be made. It is common knowledge that German manu-
facturers have for many years devoted large sums to the estab-
lishment of an efficient staff of patent experts, whose business it
is so to word a patent that, whilst it satisfies the requirements
of the patent laws of the various countries in which it is taken
out, only gives such information as is absolutely necessary, and
contains no indication of the process which is used in the actual
manufacture. In many cases patents are devised which are of no
practical value, and are merely intended to mislead and throw
competitors on the wrong scent. 1 The discovery of the most
efficient method of working patented processes is therefore often
a matter of great experimental difficulty, and may require many
months of research. Any new Company started with the object
of manufacturing dyes which previously to the war had been
made exclusively in Germany must therefore be prepared to
employ a large staff of research chemists for a long period without
any prospect of return in the way of dividends.

Further, it must always be remembered that the Germans
have many years' start of the new Company, and have accumu-
lated such vast experience of methods of manufacture, and more
particularly of the recovery and economical use of by-products,
that they are able to sell at a profit at very low prices. What

1 This point is well dealt with by Prof. Jocelyn Thorpe, F.R.S., in a letter
to the Times of 2nd February.

422 THE BRITISH COAL-TAR INDUSTRY

the new Company has to face is, therefore, in the first place, the
problem of working out methods of manufacture and the utilisa-
tion of by-products until they have arrived at the same state of
efficiency as the Germans, and that, it seems to me, may be a
matter of years. While this is being done, the new Company
must also be busily engaged in training a large body of research
chemists under the supervision of capable scientific leaders, so
that the works may develop in as many new directions as possible,
because the Company can only hope for permanent success if it
pursues a policy of discovery and invention. Another point has
also to be borne in mind, and that is that the Germans supply
dyes and other products, not only to this country, but to practi-
cally all the other nations, and, in the event of a new Company
being formed on such large lines that it might prove to be a
serious competitor, a German works could well afford to sell at
cost price or at a loss in this country and make its profits in other
lands until the new Company had been ruined. Lastly, if we
are to be allowed to make dyes, etc., during the war according
to patents belonging to the Germans, what is to happen after the
war ? Will the Company be still allowed to use these patented
processes, or will the patents again become the sole property of
the Germans, and be workable in this country only on the
payment of royalties or licences ? This matter has, no doubt,
been carefully considered by the law advisers of the Government,
but, so far as I know, no authoritative statement has been issued
which makes this situation clear. 1

1 Mr Runciman made the following reference to this important point in
Parliament on 23rd February last :

" The success of the concern would depend largely on the way in which the
German patents were administered. The Act passed last autumn as an
emergency measure provided that the operators of German patents in this
country should have a full chance of conducting them under licence, and it was
the intention of the Government not to cripple this Company when the war was
over, but to give them every opportunity of making the most of German patents.
They would leave over for discussion as between Germany and this country the
payment of royalty in respect of these patents. There were English patents in
Germany on which he hoped a royalty was being paid there. We should hand
over these royalties if Germany would bargain fairly with us. But the operating
of these patents which would be undertaken by the new Company would pro-
ceed after the war was over, without interruption and without hindrance."

If this statement means that, besides the arduous task of competing with
the well-established German works, the new Company may also have to pay
royalties or licences to those works, then it is obvious that the difficulties of
the situation will be greatly accentuated.

THE ORGANIC CHEMICAL INDUSTRY 423

Although it is a matter of so much congratulation that the
Government, which in past years has paid practically no attention
to science and the application of science to industry, should, at
last, have recognised the necessity for intervening and in no
uncertain fashion, I have been forced to the conclusion, largely
for the reasons which I have just stated, that the Company
founded on the lines of this first Government scheme could not
be expected to be successful in achieving the object which we all
have so much at heart, namely, the recovery and development of
the organic chemical industry in this country. Since the applica-
tion for shares in the proposed Company was quite insufficient,
the Government withdrew the scheme, and substituted for it an
amended proposal, which is certainly in some respects an im-
provement. 1 The new proposal is to form a Company with a
share capital of only 2,000,000, towards which the Govern-
ment will make a loan for twenty-five years, corresponding with
the amount of the share capital raised, and up to a total of
1,000,000.

In addition, and with the desire to promote research, the
Government have undertaken for a period of ten years to make
a grant to the Company, for the purposes of experimental and
laboratory work, up to an amount not exceeding in the aggregate
100,000.

This amended proposal is another proof of the determination
of the Government to meet the criticisms which were raised
against the first scheme in a generous spirit, and to do all it
possibly can to assist the efforts of the manufacturers in this
country to place the organic chemical industry on a firm basis.
If, then, I make certain criticisms of the new proposal, it must be
clearly understood that I do not do so in any spirit of hostility
to the scheme, but rather in the hope that the adoption of some
modifications in the proposals may make the scheme workable
and more likely of success. In the first place I hold that the
scheme must be considered in the light of the criticisms which
I have just advanced in connection with the first Government

1 The members of the enlarged Committee which is responsible for the
second scheme are Sir A. F. Firth, Bart., Sir Frank Hollins, Bart, Sir Mark
Oldroyd, Mr H. W. Christie, Mr J. Clarkson, Mr Charles Diamond, Mr
Kenneth Lee, Mr G. Marchetti, and Mr R. D. Pullar ; and, in spite of Prof.
Meldola's letter and other letters to the Press, again did not include expert
chemical opinion.

4 2 4 THE BRITISH COAL-TAR INDUSTRY

plan, and I hope that these points will be clearly handled in any
detailed statement of this or any subsequent scheme.

There are, however, other matters which call for comment.
The grant for scientific research may be welcomed as a satis-
factory addition to the old proposal, mainly because it shows
that the Committee of users of dyes have at last found out
that research is necessary if the new Company is to be a suc-
cess. My own feeling, however, is that the Company ought
to provide for research out of its ordinary capital as a matter
of course, and should not require a special subsidy for this
purpose.

A much better plan, I venture to think, would be to employ
this grant to subsidise the research laboratories of those universi-
ties and technical schools which are willing to specialise in organic
chemistry, and are prepared to train a certain number of research
students with the definite view of their subsequently entering the
service of the new Company. Supposing the new Company
were to adopt the view which I have urged in this address, that
closer connection between the universities and the industries is
most desirable, and were to work in conjunction with the staffs
of some of the leading organic schools, it is quite obvious that
the knowledge of the needs of the works which would result
from this connection would enable the staff to supply research
students of exactly the type required by the works. Such
research students would have been trained under the best
scientific supervision which the country can provide, and at the
same time they would enter the works with a considerable
knowledge of the application of organic chemistry to technical
operations, and be in a position to tackle with success research
problems connected with new discoveries and new developments
in the works. The plan of training research students under
these conditions is, as I have already pointed out, the one which
has long been adopted with such extraordinary success in
Germany, and the large subsidies which the various States place
at the disposal of their universities allow of the purchase of
expensive apparatus and appliances which are outside the in-
adequate resources of most of the university laboratories of
this country.

With regard to the kind of works it is proposed to organise
for the manufacture of dyestuffs, etc., which previous to the war
had been made in Germany, it would be well carefully to consider

THE ORGANIC CHEMICAL INDUSTRY 425

the policy which the Germans have adopted with so much success
in the matter of the construction and arrangement of their works.
I think that one of the things which must strike a visitor to a
great German works more perhaps than any other is the order
and cleanliness which reigns everywhere, and the obvious care
which is taken that every manufacturing operation shall be
efficient in every detail. This order and cleanliness is not con-
fined to the section of the works which deals with organic pro-
ducts ; the same state of things is to be observed in every part,
as, for example, in the case of the large plants which deal with
the manufacture of sulphuric acid, nitric acid, and other inorganic
products. Perhaps the idea which is conveyed most vividly by
works such as these, all of which are concerned with the manu-
facture of a very large number of products of widely differ-
ent character, is that they are, after all, merely laboratories on a
larger scale.

A very different impression is got by an inspection of many
of the colour works in this country, and it seems to me very
doubtful policy to suggest the possibility of the acquisition of
works of this kind, which are obviously not efficient, and could
only be made so by pulling down and re-building. It may be
said that the most efficient only will be taken over, but selection
will be found most difficult, because, if the new Company proves
a success, great pressure will be exerted by existing works in
order to enter the charmed circle, and the argument of unfair
competition will be used for all it is worth, and will be very
difficult to deal with. Again, it is most important not to lose
sight of the fact that the experience of the Germans is all in
favour of building up very large works, and against spreading
manufacturing operations over small works situated in different
parts of the country.

The reason for this is obvious. In the manufacture of any
substance, by-products are almost always produced which must
either be recovered or used in the manufacture of other saleable
products ; otherwise serious loss is inevitable. It is exactly in
this respect that the Germans are so efficient, and the wonderful
organisation which enables them to dovetail one process into
another is one of the reasons why the comparatively small works
in this country find it impossible to compete with them even in
the manufacture of such simple substances as salicylic acid or
/3-naphthol. In order that by-products may be used to the best

426 THE BRITISH COAL-TAR INDUSTRY

advantage it is obviously essential that all these dovetailing
operations must be carried out on the same site, so that it may
not be necessary to transport the by-products from one works to
another, an operation which could not fail to entail loss. Prob-
ably the best course for the new Company is either greatly to
enlarge the works of Messrs Read Holliday & Sons, or, if it is
difficult to find space for this purpose in Huddersfield, to take
steps to acquire a suitable site and erect and equip works thereon,
a plan which is mentioned in the explanatory statement as one of
the objects of the new Company.

Let us suppose that, in the near future, a practically new
works is built on a large scale, and with all the most modern
appliances, and that the control of the whole works and of the
different departments is placed in the hands of efficient chemical
leaders with adequate staffs of chemists under their charge, and
that the Company has also large and well-equipped research
laboratories busily engaged in discovering new developments and
improvements on existing processes ; what prospect has such a
works of competing successfully with the existing German
organisations and of obtaining a fair share of the organic chemical
industry ?

In answering this important question it must again be empha-
sised that the German works with which the new Company must
compete are enormous organisations controlling almost unlimited
resources and in a most flourishing condition.

The Farbwerke, vormals Meister, Lucius & Brtining, in
H5chst, employs, for example, 350 chemists, 150 engineers and
technical experts, 600 clerks, and about 10,000 workmen. The
probability of successfully competing with several organisations
of this kind, grouped, as they are, in combines in order the more
readily to be able to crush competitors and secure the monopoly
of the industry, also depends, no doubt, to a great extent on the
condition of the German chemical industries after the war. If
we suppose that the German companies will continue to work
with the same efficiency as before, or will rapidly regain that
efficiency, I am inclined to think that we must be prepared to
face the certainty that some years must elapse before we can
compete successfully against organisations which have taken
years to develop and bring to perfection.

Failure to develop on research lines is scarcely conceivable
if the works is in charge of a highly trained chemical staff, but,

THE ORGANIC CHEMICAL INDUSTRY 427

on the other hand, if it gets into the power of the business man
who wants an immediate return for his outlay, is not willing to
wait for results, and fails to appreciate the importance of scientific
control, then no tariff can avert disaster. I am sure we shall all
watch the course of events with the greatest interest, and hope
that the new venture may have a large measure of success, and
bring back to this country at least a tithe of the prosperity which
attaches to the organic chemical industry.

INDEX OF NAMES

Abel, F. A., 59, 75, 144, 158.
Allhusen, C., 317.
Anderson, 51, 52, 53,91,236.
Anderson, J., 419.
Arkwright, 284.

Armstrong, H. E., 69, 191, 192, 194,
221, 222.

Babbage, 284.

Badische Anilin- und Soda-Fabrik, 74,
85, 94, 97, 119, 136, 190, 196, 198,
199, 202, 205, 207, 208, 210, 219,
220, 247, 248, 255, 257, 272, 301,
308, 312, 320, 326, 327, 365, 368,
382, 390.

Baeyer, A., 50, 53, 74, 95, 97, 98, 122,
123, 200, 204, 205, 207, 263, 264,
265,272,315, 324,411.

Bardy, 173, 174.

Barlow, T., 148.

Barnes, W. C., & Co., 135.

Bayer, F., & Co., 198, 210, 224,225,414.

Beaconsfield, Lord, 190.

Beale, 241.

Bechamp, 9, 77, I53> 238.

Beilby, G. T., 419.

Beilstein, 169.

Berlin Aniline Co., 198, 301.

Bernthsen, A., 102, 131, 193, 224, 325.

Berry, A. E., 331.

Berthelot, 51, 52.

Berzelius, 315.

Bessemer, H., 284.

Besthorn, 127, 129.

Bethels Tar Works, 146.

Bindschedler & Busch, 365, 366.

Bindschedler, H., 366, 367.

Birkeland, 381.

Black, J., & Co., 78, 134-

Bloxam, A. G., 269, 279.

Boettger, 382.

Bottiger, 192.

Bowrey, J. J., 145-

Boyle, R., 284.

Bradford Dyers' Association, 197.

Brandenburg, 63.

Bretonniere, 194, 265.

British Alizarin Co., 135, 229, 290, 311,
312.

British Cotton and Wool Dyers' Associa-
tion, 197.

Brooke, Simpson & Spiller, 64, 126, 198,
237,250,303,410.

Brougham, Lord, 398.

Brown, J. T., 145.

Brunck, H., 204, 219, 221, 324, 326.

Brunner, J. T., 63.

Brunner, Mond & Co., 388.

Bunsen, R., 146.

Burt, Bolton & Heywood, 56, 117, 250.

Burwell, 219.

Cahours, 85, 147.

Cain, J. C., 243, 278, 294, 297.

Calvert, C., 33.

Caro, H., 12, 52, 58, 63, 74, 86, 89, 91,
95, 98, 99, H5, 122, 123, 125, 130,
136, 148, 154, 168, 170, 178, 184,
206, 242, 243, 246, 247, 248, 249,
253, 255, 257, 262, 263, 264, 271,
3oi, 303, 3i6, 324.

Cartwright, 284.

Cassal, C. E., 333.

Cassella, L., & Co., 196, 198.

Chapman, A. C., 330.

Chapman, E. T., 61.

Chapman, Messel & Co., 250, 255.

Chapman, S., 190.

Chapoteaut, 163.

Chardonnet, Count, 382.

Chemische Fabrik Griesheim-Elektron,
214.

Cherpin, 29, 171.

Christie, H. W., 420, 423.

Church, A. H., 33, 35, 99, 147, 150.

Clarkson, J., 423.

Glaus, 129.

Claus & R^e, 198.

429

430

THE BRITISH COAL-TAR INDUSTRY

Clayton Aniline Co., 198.
Cliff, 146.
Clowes, F., 145.
Coblentz, 242.
Coke, Lord, 392.
Coleman, J. B., 301.
Colin, 48, 53.
Collas, in.
Coupler, 122.
Cox Bros., 133.
Crace-Calvert, 254.
Croissant, 194, 265.
Crookes, W., 145.
Crum, Walter, & Co , 134.

Dale, J., 12, 52, 81, 99, no, 154, 170,

242, 301.

Dalmonach Print Works, 155.
Dalton, 284, 315.
Darwin, F., 284.
Davy, H., 284, 3I5-
Davy, J., 89.

Dawson, Dan, & Co., 301.
Deacon, 214.
Deering, W. H., 145.
De Laire, 82, 84, 122, 159, 161, 163,243,

253-

De .a Rue, 158.
De"pouilly, P. E., 37, 241.
Dewar, J., 118, 129, 138, 222, 284.
Diamond, C., 420, 423.
Diesbach, 380.
Divers, E., 145.
Dobbie, J. J., 330, 419.
Dobereiner, 29.
Doebner, O., 63, 85, 262.
Dower, 254.
Dreaper, W. P., 279.
Drewsen, W., 207, 264.
Duisberg, C., 282, 289, 292, 294, 325, 414,

415,416.

Dumas, A., 53, 91, 142, 146, 164, 236, 315.
Duprey, F., 174.
Dusart, 178.

Emmerling, 205.

Engler, 205.

English Sewing Cotton Co., 197.

Ewer & Pick, 131.

Eyde, 381.

Faraday, M., 5, 47, 53, 79, 109, no, 123,

141, 186, 235, 284.
Farbenfabriken Elberfeld (see F. Bayer

& Co.).

Farbwerke Hoechst (see Meister, Lucius

& Briining).
Feilmann, E., 279.
Fichte, 346.
Field, F., 32.
Filehne, 118, 119.
Firth, A. F., 423.
Fischer, E., 60, 85, 86, 119, 125, 193,262,

315, 320, 321, 324, 367, 370.
Fischer, O., 60, 84, 85, 86, 11 8, 125, 126,

127, 129, 262, 265, 324, 367.
Fluerscheim, 382.
Forster, M. O., 348.
Foster, H. A., 310.
Franc Bros., 241.
Frankland, P., 379.
Friswell, R. J., 60, 69, 138.
Fritsche, 4, 142, 187.

Gallik, 97.

Garden, 142, 235.

Gardner, W. M., 314, 371.

Gay-Lussac, 315.

Gessert Freres, 57, 255.

Geyger, A., 170, 175.

Gilliard, Monnet & Cartier, 207.

Girard, C. H., 82, 84, 122, 159, 161, 171,

243, 253-

Girard and De Laire, 21, 22, 163.
Glaser, 325.
Gordon, J. W., 389.
Gossage, W., 317.
Gossling, F., 419.
Graebe, C., 46, 50, 52, 53, 56, 57, 63, 69,

91, 93, in, 122, 130, 177, 178,

179, 183, 205, 245, 246, 247, 248,

250, 262, 271, 302, 324.
Graham, C., 70, 284.
Grassier, F., 122.

Green, A. G., 189, 294, 323, 331, 419.
Greenford Green Works (see Perkin

& Sons).

Grey, M., 40, 155.
Gness, P., 65, 69, 99, 115, 148, 167, 168,

170, 254, 271, 301, 324.
Gnmaux, 85.
Guinon, Marnas & Bonnet, 35, 80, 83,

154.
Guyot, 242.

Haber, 320, 382.
Haen, de, 408.
Haessermann, 382.
Haldane, Lord, 402, 419.
Hall, T., 144, 145.
Hanhart, 42.

INDEX OF NAMES

Harrmann, 120.

Harvey, A., & Son, 133.

Henderson, 222, 340.

Hepp, E., 193, 265.

Heumann, K., 210, 211, 272.

Heys, Z., & Sons, 134.

Hickson, E., 132, 313.

Higgin, 49.

Hobrecker, 172.

Hoff, R., 178.

Hofmann, A. W., 4, 6, 17, 20, 21, 23, 25,
26, 27, 44, 45, 80, 81, 86, 100, 108,
1 10, 126, 130, 142, 143, 145, 156,
1 5%) J 59 5 J 6o, 162, 164, 166, 167,
169, 170, 171, 172, 174, 175, 176,
177, 1 86, 187, 201, 211, 235, 236,

242, 246, 253, 254, 262, 278, 300,
301, 302, 316, 321, 324, 390.

Hollins, F., 423.
Holzmann, 167.
Hoogewerff, 211.
Howard, D., 419.
Huxley, T. H., 284.

Jacobson, E., 176.
Julius, P., 170.

Kahlbaum, 408.

Kalle & Co., 208.

Kay, 242.

Kehrmann, 193.

Keisser, J., 170.

Keith, T., & Sons, 78, 152, 240, 300.

Kekule, 50, 51, 53, 178, 185, 261, 262,

268, 322, 324, 411.
Kelvin, Lord, 284.
Kern, A., 89.
Kirkham, 241.
Knietsch, R., 213, 215.
Knorr, L., 119.
Koch, J. J., 94, 249.
Koechlin, H., 117, 118, 123.
Kolbe, 34, 83.
Kopp, E., 28, 164, 165.
Korner, G., 129.
Kostanecki, 193.
Kiihlberg, 169.

Laubenheimer, 325.

Laurent, 37, 51, 53, 65, 91, 142, 146, 236.

Lauth, C, 29, 61, 84, 85, 171, 172, 241,

244, 260, 262, 264.
Le Bel, 31 5.
Le Blanc, 380.
Leckie & MacGregor, 133.
Lee, K., 423.

Lee, L., 420.

Lefevre, 195.

Leibius, 167.

Leigh, J., 1 10.

Leonhardt, A., & Co., 198.

Levinstein, H., 220.

Levinstein, I., 117, 135, 200, 203, 275.

Levinstein Ltd., 198, 390, 419.

Liebermann, C., 46, 50, 52, 53, 56, 57,91,
93, in, 122, 177, 178, 183, 193,
205, 245, 246, 247, 248, 250, 271,
302, 324.

Liebig, 29, 109, 1 10, 315, 411.

Liggins, 140.

Lightfoot, J., 254.

Limpricht, 85.

Linde, C., 381.

Lowe, 254.

Luynes, de, 24.

Macara, C. W., 288, 377.

M'Kendrick, 118.

M'Leod, 162.

Mansfield, C. B., 6, in, 123, 142, 158,

187, 235, 236, 237, 242.
Manson & Henry, 133.
Marchetti, G., 420, 423.
Martius, 35, 117, 169, 174, 253, 301.
Maule, 253.

Maw, H. W., 350.

Medlock, H., 18, 82, 121, 124, 157, 158,

243, 253, 301.
Meister, Lucius & Briining, 68, 126, 136,

198, 205 208, 308, 312, 365, 368,

370, 426.
Meldola, R., 64, 65, 68, 70, 121, 140,

1 88, 191, 219, 220, 227, 228, 233,
234, 257, 259, 284, 294, 322, 323,
401, 406, 419, 420, 423.

Mene, 99.

Merck, E., 408.

Messel, R., 190, 255, 348, 350.

Michaud, 381.

Michler, 89, 90.

Miller & Co., 153, 236.

Mitchell, W. A., 135.

Mitscherlich, E., 7, 65, 77, 109, no, in,

142, 187,315.
Mond, L., 388.
Monnet and Drury, 159.
Mortimer, 144.
Moulton, Lord, 345, 347, 351, 371, 402,

415,416,419.
Miiller, H., 21, 34, 248.
Mundella, 389.
Musprat, 142.
Musprat, M., 419.

432 THE BRITISH COAL-TAR INDUSTRY

Natanson, 17, 159.

Newlands, J. A., 145.

Newton, J., & Son, 132.

Nicholson, E. C., 21, 24, 64, 82, 86, 99,
121, 124, 126, 157, 158, 160, 161,
163, 187, 201, 237, 238, 253, 279,
301.

Nietzki, R., 80, 81, 194, 204.

Nobel, A., 382.

Ogilvie, F. G., 349-
Oldham, G. W., & Co., 132.
Oldroyd, M., 423.
Ormandy, W. R., 335.
Orr-Ewing, John, & Co., 134.

Page, F. J. M., 145.
Paquier, 381.
Peachey, 315.
Pedler, A., 145.
Peligot, 1 10.

Perkin, F. M., 221, 298, 321, 336.
Perkin, T. D., 150, 243.
Perkin, W. H., I, 46, 52, 54, 69, 75, "i,
118, 120, 121, 124, 125, 136, 141,

145, 201, 232, 233, 234, 236, 237,
238, 239, 240, 241, 242, 243, 244,
246, 247, 248, 249, 250, 251, 252,
254, 255, 257, 259, 260, 265, 269,
270, 284, 294, 298, 301, 302, 316,
321, 384, 390.

Perkin, W. H., Jim., 407, 419.

Perkin & Sons, 152, 229, 237, 238, 239,

240, 243, 250, 251, 253, 254, 260,

300, 301, 303, 410.
Persoz, J., 24, 34, 35.
Phillips, C., 242.
Poirrier & Chapat, 28, 61, 84, 115, 173,

260.

Pope, W.J., 315-

Price, A. P., 82, 242.

Price, D., 157, 158,301.

Priestley, 284.

Pullar, R., 39, 124, 132, 152, 154, 234,

240, 241, 298. .

Pullar, R., & Son, 150, 152, 236, 240,

241, 298.
Pullar, R. D., 420, 423.

Ramsay, W., 284, 328.

Rawson, C., 221.

Read Holliday & Sons, 193, 243, 301,

426.

Reichenbach, 176.
Reid, W. F., 332, 349-

Renard Freres, 17, 156, 159, 270, 316.
Ripley, E., & Son, 132.
Roberts, A., 349.
Roberts, Dale & Co., 253, 301.
Robiquet, 48, 53.
Roemer, 93, 183.
Roscoe, H. E., 46, 71, 106, 365.
Roussin, Z., 115, 118, 169.
Royle, T., 135.
Rudolph, C., 126.
Runciman, W., 422.

Runge, F., 4, 15, 34, 79, 142, 186, 235,
236.

Salvetat, 24.

Samuelson, B., 389.

Sapper, E., 213.

Schering, 408.

Scheurer-Kestner, 241.

Schiendl, 169.

Schimmel & Co., 325.

Schmitt, R., 34, 83.

Schoenbein, 382.

Schorlemmer, 52, 81, 254.

Schultz, A., 40, 155, 163, 240.

Schultz, G., 286.

Schunck, E., 48, 49, 53, 91, 93, 183.

Seidel, P., 215.

Sharp, M. S., 419, 420.

Simon-Carves, 108.

Simpson, Maule & Nicholson, 77, 82,

122, 126, 157, 158, 161,237, 238,

242, 243, 253, 301, 303.
Singer, I., 280, 294.
Skraup, 119.
Smiles, 215.
Smith, 242, 301.
Sobrero, 382.
Soci6te des Usines du Rhone (see

Gilliard, Monnet & Cartier).
Spiller, J., 69, 145.
Spiller, W., 237, 238, 243.
Starck, J. D., 242, 255, 256.
St Claire Deville, 148.
Stephenson, R., 284.
Stevenson, J., & Co., 133.
Stirling, W., & Sons, 134.
Strecker, 53.

Tabourin, 241.
Tedder, A. V., 419.
Templeton, J., & Co., 133.
Thenard, P., 147.
Thomas, E., 254.
Thompson, W. P., 198.
Thorp, W., 145.

INDEX OF NAMES

433

Thorpe, J., 421.

Tiemann, 120.

Tilden, W. A., 315,347, 348.

Turkey-Red Dyers' Association, 305,

312.

Turner, J., 419.
Tyndall, 284.
Tyrer, T., & Co., 219.
Tyrer, C., 219.
Tyrer, T., 309, 419-

Unverdorben, 4, 5, 70, 77, 97, 142, 186.

Van Dorp, 211.

Van'tHoff, 315.

Verguin, 17, 81, 156, 159, 242, 243, 300,

316.

Verneuil, 381.
Vidal, R., 194, 272.
Vignon & Co., 272.

Walker, W., & Son, 132.

Wanklyn, 86.

Watts, 284.

Weldon, 214.

Williams, C. G., 28, 101, 166, 242, 244,

254, 301.
Williams, Thomas & Dower, 245,

301.

Wilton, T., 219.
Winckler, C., 190, 213, 250, 255,

256.

Witt, 145.
Witt, O. N., 67, 69, 80, 99, 115, 1 1 8, 122,

123, 195, 264, 301, 324.
Wohler, 411.
Worstall, 219.
Wiirtz, 51, 178.
Wynne, 192.

Zinin, 4, 9, 65, 77, 142, 187, 238.

INDEX OF COLOURING MATTERS

Acid green, 116, 192.

magenta, 192, 228.

violet, 192.

yellow, 116, 122, 265.
Acridine orange, 194.

yellow, 194.

Aldehyde green, 29, 84, 171, 260.
Alizarin, 46, 54, 57, 91, 112, 113, 114,
116, 122, 134, 136, 177, 178, 181,
183, 194, 199, 228, 229, 245, 246,
247, 248, 252, 260, 271, 290, 291,
302, 305, 369, 412.

blue, 94, 101, 265, 290.

Bordeaux, 194.

cyanine, 194.

orange, 94, 290.

saphirole, 194.

viridine, 194.
Alkali blue, 83, 116.
Alkaline green, 63.

Aniline black, 40, 194, 254, 291,
302.

blue, 22, 43, 82, 88, 159, 161, 162, 163,
164, 192, 228, 229.

pink (see Safranine).

purple (see Mauve).

red (see Magenta).

yellow, 122, 124, 192, 228, 253, 260.
Anthracene blue, 194.
Anthrapurpurin, 92, 116, 181, 183.
Auramine, 116, 192, 228, 230.
Aurine, 34, 86, 113, 114, II 6.
Azodiphenyl blue, 122.
Azuline, 35, 83.

Benzaldehyde green, 84, 88, 90.
Benzoflavine, 194.
Biebrich scarlet, 116, 123, 265.
Bismarck brown, 66, 99, 100, 116, 122,

124, 192, 228, 253, 260.
Blackley blue, 116.

red, 391.

Bleu de Lyons (see Aniline blue).
Bleu de Paris, 24.

Blue black, 265.
Bordeaux, 100, 116, 265, 291.
Brilliant green, 85, 88, 116, 228, 230.
Britannia violet, 28, 83, 166, 245, 251,
252, 260.

Cachou de Laval, 194, 265.
Carminaphtha, 37.
Chloramine yellow, 193,
Chrysoidine, 67,99, Io , II 5, n6, 122,

175, 192, 228, 265.
Clayton yellow, 193.
Cochineal, 112, 158, 199.
Coerulei'n, 265.
Congo red, 192, 265.
Corraline (see Peonine).
Crocein scarlet, 116, 123, 192.
Crysaniline (see Phosphine).
Crystal violet, 228, 230, 262.
Cumidine scarlet, 116.
Cyanine, 101, 166, 167, 253, 301.
Cyanosin, 116.

Dahlia, 27, 45, 79,251.
Diphenylamine blue, 63, 116.
orange, 116.

Eosin, 95, 116, 122, 175,369-
Erica, 193.
Erythrosin, 116.
Ethyl violet, 166.

Fast red, 100, 265.

yellow, 100.
Field's orange, 32.
Flavaniline, 101, 126, 265.
Flavopurpurin, 93, 116, 181.
Fleur de Garance, 49, 178, 179.
Fluorescein, 95.
French purple, 154.
Fuchsine (see Magenta).

434

INDEX OF COLOURING MATTERS

435

Gallein, 122, 265.
Gallocyanin, 228.
Garancine (see Fleur de Garance).

Helianthine (see Orange III.).

Hofmann's violet, 25, 44, 60, 83, 102,
165, 173, 192, 228, 229, 230, 231,
241, 244, 251, 260, 262, 279, 301.

Immedial black, 195.

blue, 195.

Imperial violet, 24, 82, 159, 161, 163.
Indigo (artificial), 199, 204, 205, 216, 217,
219, 265, 272, 273, 292, 308, 314,
316, 323, 369, 412.
(natural), 71, 97, 98, 117, 123, 199, 204,

216, 217, 219, 309, 323.
pure, 219.
salt, 208, 215.
Indoine blue, 194.
Indophenol, 115, 117, 123, 265.
Indophor, 215.
Induline, 116, 228, 253, 260.

scarlet, 194.

Iodine green, 30, 63, 84, 166, 170, 173,
228, 229, 230, 260.

Janus dyes, 193.

Katigene black, 195.
brown, 195.
green, 195.

Lauth's violet, 173, 264.

Madder, 48, 55, 112, 178, 179, '99, 245,
302, 323-

Magdala red, 99, 169.

Magenta, 16, 17, 18, 19, 20, 38, 43, 60,
81, 102, 113, 114, 116, 122, 124,
154, 156, 158, 161, 162, 192, 228,
241, 242, 243, 244, 251, 253, 262,
263, 270, 300, 301, 316, 369.

Malachite green, 63, 84, 116, 122, 192,
205, 228, 230, 231, 262, 367, 412.

Manchester brown (see Bismarckbrown).
yellow, 36, loo, 116, 124, 228, 253, 260.

Martius yellow, 99, 169.

Mauve, 5, 39, 76, 121, 124, 149, 151, 154,
160, 161, 165, 174, 234, 239, 240,
241, 242, 251, 254, 265, 270, 298,
299, 3o

Meister's scarlet, 100.
Meldola's blue, 194.
Metanil yellow, 116.
Methyl green, 63.
violet, 62, 88, 114, 116, 192, 228, 230,

231, 244, 260, 262, 369.
Methylene blue, 101, 116, 122, 194, 228,

230, 264, 271.
Murexide, 269.

Naphthalene red, 170.
Naphthazarin, 169.
Naphthol orange, 228, 265.
yellow, 112, 114, 116, 265.
Neutral violet, 265.
Nicholson's blue, 24, 39, 83, 163.
Night blue, 228, 230, 231, 262.
Nitroalizarin (see Alizarin orange).
Nitrosophenyline, 33.

Opal blue, 64.
Orange I., 116.
Orange II., 116.
Orange III., 116.
Orange IV., 116.

Paranitraniline red, 193, 291.

Peonine, 34, 83.

Perkin's green, 31, 166, 252.

violet (see Mauve).
Phloxin, 96, 1 1 6.
Phosphine, 21, 101, 126, 129, 164, 192,

194, 228, 253, 260.
Picric acid, 33, 228, 253, 269.
Pittacal, 176.
Ponceau 2 R, 100, 265.
Printline, 193, 278.
Propiplic acid, 206, 215.
Prussian blue, 269.
Purpurin, 49, 92, 183.
Pyrogene blue, 195.

Quinoline blue (see Cyanine).
red, 176.

Regina, 163.
Rhodamine, 194, 264.
Rhoduline, 194.
Roccellin, 116.
Rosaniline (see Magenta).
Rose Bengal, 116.
Roseine (see Magenta).
Rosinduline, 194.

43 6

THE BRITISH COAL-TAR INDUSTRY

Rosolic acid (see Aurine).
Runge's blue, 1 5, 79.

Safranine, 31, 80, 116, 174, 175, 194,228,

251, 265.
Safrosin, 116.
Soluble blue, 24, 88, 163.
Sun yellow, 265.

Tartrazine, 265.
Thioflavine, 193.
Tropaeoline o, 67, 115, 122.
Tropaeoline oo, 67.

Turmerine, 193.

Tyrian purple (see Mauve).

Vermilline scarlet, 113, 114, 116.
Victoria blue, 90, 116, 192, 230, 231,

262.

green, 84.

Vidal black, 195, 272.
Violet de Paris, 173.
Violine, 301.

Xylidine red, 168.
scarlet 116, 192.

TABULAR AND STATISTICAL
INFORMATION

Alizarin, annual production of, in

1869-1873 .... 57
chronological history of . . 53
Alkali trade production, 1852-1861 317
Anthracene dyes, British patents,

1855-1905 .... 271
Azo dyes, British patents, 1855-

1905 272

Badische Anilin- und Soda-Fabrik,

statistics relating to . . 220
Bayer, F. & Co., statistics relating to 224
Coal, distillation products of. .2, 47
products obtainable from 100 Ibs.

of 13

Coal-tar, amount distilled for colour-
making in 1890 . . . 286
weight of various dyes obtain-
able from . . . .114
Coal-tar dyes, British imports,

1886-1900 .... 197
British patents, 1885-1905 . 270
dyeing power of colours obtain-
able from i ton of coal . 114
German exports of . . .196
imports from Germany in 1913 . 319
list of (in 1886), arranged accord-
ing to origin . . .116

Coal-tar dyes, list of those produced

by Perkin & Sons . -251
British and German, used in

Britain in 1865 . . 133-136

in 1900 197

statistics relating to . . . 383
value produced in 1878 . . 58

Coal-tar products, British imports

and exports in 1909 . . 285
German exports of . . .195

German colour works, statistics

relating to . . . .198

Indigo, value of world's produc-
tion ... 71, 217, 220

Indigo dyes, British patents, 1855-

1905 . . . . .270

Madder, annual imports of . 55> 5^

Meister, Lucius & Briining, statis-
tics relating to . . 369, 370

Patents, numbers taken out by

British and German firms . 198

Perfumes, natural and synthetic . 384

Rosaniline dyes, British patents,

1885-1905 . . . .271

Sulphide dyes .... 273

Sulphuric acid and soda, world's

production .... 384

437

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