August 5, 1886] 
ones, such as Free Trade, the Patent Laws, or the available 
energy of a British as compared with a German workman under 
the stimulus of a certain amount of weekly wage. These and 
kindred questions—such as the cost of railway carriage, or the 
relative ideas of ‘‘making a manufacture pay”’ which may exist 
in the British and Teutonic minds—have, doubtless, a most im- 
portant bearing upon the main subject, but their discussion 
would occupy far too much time, and would, moreover, be out 
of place in this Section. I might even go so far as to express 
a private belief that if this portion of the subject were handed 
over for legitimate treatment by economists, the conclusions 
arrived at (if any) would hardly be commensurate with the 
amount of discussion which would be evoked. In fact, it 
appears to me that although, in a general way, each of the 
causes mentioned must be a factor in determining the success of 
any branch of manufacture, it is quite impossible to assign its 
true value to each of these factors ; and in the case of the pre-. 
sent industry I am persuaded that it is now a question of 
chemical and not of economic science that is pressing for con- 
sideration. 
It will, I think, be conceded that the manufacture of coal-tar 
products is far excellence the most scientific of the chemical in- 
dustries. This high position may fairly be claimed for the in- 
dustry when we consider the number and complexity of the 
products, the delicacy of many of the reactions employed, the 
special arrangements of plant required, and the intimate know- 
ledge 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 rea ons 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 treating of the industrial development of a branch of 
chemical manufacture, it is important that we should begin with 
a distinct idea of the products themselves. I must claim the 
indulgence of chemists if at this stage I find it necessary to go 
over somewhat old ground, and to slate facts with which so 
many are familiar. It would, of course, be quite impossible to 
give, on the present occasion, anything like a complete chrono- 
logical list of the various colouring-matters, and it would be 
equally impossible for me to enter into the discussion of the 
chemical structure of the beautiful compounds which are now to 
be met with in the market. If, later on, I find it necessary to 
enter into questions of chemical constitution, it will be chiefly 
with the object of illustrating general principles by appealing to 
particular cases. Inthe brief historical sketch which I now pro- 
pose to lay before you, I shall mention only those discoveries 
which may be considered to mark distinct commercial epochs in 
the development of the industry. The successive steps in this 
development will furnish us with one of the most striking illus- 
trations 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, 
a violet dye, obtained accidentally in the course of an investiga- 
tion having forits object the preparation of quinine by an arti- 
ficial 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 dis- 
covery of the arsenic acid process by Medlock and E. C. Nichol- 
son simultaneously. During this same year phenylated blues 
were first produced by Girard and De Laire, by the action of 
aniline upon magenta base at a high temperature. These blues 
had Lut 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 sul- 
phonic acids. The first azo-colour, amidoazobenzene, a basic 
yellow dye, was introduced in 1863 by the firm of Simpson, 
Maule, and 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 ‘* Hof- 
mann violets,” inhonour of theirdiscoverer. ‘* 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 Man- 
chester. The same year (1866) was marked by the introduction of 
Coupier’s nitro-benzene process for the manufacture of magenta. 
NATURE 325 
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 ‘‘ phthaleines,” viz. gallein and fluorescein, were 
discovered by Baeyer in 1871; and the first technical applica- 
tion of this discovery was made in 1874 by Caro, who intro- 
duced the beautiful pink tetrabromfluorescein into commerce, 
under the name of ‘‘eosin.” Diamidoazobenzene was dis- 
covered by Caro and Witt independently in 1875, and was in- 
troduced into commerce by the latter as ‘‘ chrysoidine.” A 
great impetus was given to the technical production of azo- 
colouring matters by this discovery, the naphthol oranges and 
other ‘‘tropceolines,” fast-red, the ponceau scarlets, &c., 
appearing in 1878. Methylene blue and acid magenta were 
introduced by Caro in 1877, and in the same year the old and 
fugitive ‘‘aniline yellow” was converted into a valuable acid 
yellow by Grissler, who patented a process for converting the 
base into a sulphonic acid. Malachite green was introduced in 
1878, and in 1879 the first member of the now important group 
of secondary azo-compounds appeared under the name of Bie- 
brich scarlet. It is these secondary azo-scarlets, and especially 
the ‘‘croceine scarlets” (discovered in 1881) which are exter- 
minating 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 
1881, 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 colour- 
ing-matters from coal-tar which are, or have been, of industrial 
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 far? 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 manufac- 
{urer 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 gradually falling off, or be compelled to wake up to the 
unpleasant fact that his competitors are underselling him, owing 
to improved methods of manufacture. ; j 
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 
who, in 1847, first isolated this substance in large quantities 
from coal-tar, and showed how nitro-benzene could be manufac- 
tured 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 
“*Manchester 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 behoyes 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, 
