326 
NATURE 
as well as being among the largest consumers of the dyes them- 
selves. 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 anount 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 manufac- 
turing system. 
Before submitting to you the statistics of this industry which 
I have been able to collect, I think it 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. It will serve my purpose equally well, or perhaps 
even better, toconfine 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 toa ‘‘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 ‘‘ immediately 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 develop- 
ment of this and many other industries is mainly due to the 
complete and thorough recognition, on the part of our com- 
petitors, of the vital importance 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 ¢echnigue 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 isa matter of 
perfect indifference whether I take by way of illustration pro- 
ducts which have been successful from a financial point of view 
or not. In order to give greater emphasis to the principle, I 
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. 
In 1863, Mr. E. C. Nicholson discoyered 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, and Nicholson, 
and the colour was introduced into the market under the name 
of ‘“‘phosphine.” This dye was the first basic orange dis- 
‘covered, 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 esta- 
blished_ in 1863 by Hofmann, who assigned the formula 
CyoHy,;N,.H,O, and described the base under the name of 
chrysaniline, Although other and cheaper basic orange colour- 
ing-matters have since been discovered, chrysaniline still finds a 
distinct use ; and Iam informed by Messrs. Brooke, Simpson, 
and Spiller that the amount of this colour now sold is not appre- 
ciably less than at the time of its introduction by their prede- 
cessors. {, The chemical constitution of chrysaniline remained 
unknown till about two years ago, when the problem was solved 
by O. Fischer (Berichte, 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 (Berichte, 1882, 
p- 1500). Flavaniline was produced by the action of dehydrat- 
ing agents, such as zinc chloride, upon acetanilide, this fact 
having been observed by Rudolph in 1881, and the practical 
manufacture of the colour having been carried on under a patent _ 
by Messrs. Meister, Lucius, and Briining, of the Hoechst colour- 
works.' Supplied with a large quantity of the pure crystalline 
material by the manufacturers, Messrs. Fischer and Rudolph 
established the formula of flavaniline, C,,H,,N», and showed 
that its formation from acetanilide might be expressed by the — 
equation :— 
2C,H;. NH. C,H,0—20H, = C,,H,4No. 
By the action of nitrous acid upon flavaniline a diazo-com- 
pound was produced which, by the usual method of decomposi- 
tion by water, gave a phenolic derivative termed flayenol, and 
possessing the formula Cj,H,,N . OH, thus proving that flavani- 
line contained a displaceable NH, group. By heating flavenol 
with zinc dust, a base was obtained having the formula C,,H,,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 flavani- 
line 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 (erichle, 1883, 
p- 68) it was announced that flavenol, when oxidised by potas- 
sium permanganate in an alkaline solution, gave an acid which, ~ 
I g ’ 
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 (Berichte, 1884, 
Pp. 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 :— 
CygHy.(N H,)N CygHy(OH)N. 
Flavenol gave, as the first product of oxidation, lepidine-car- 
bonic acid, of which the formula is C;,HgN(CO,H), and by 
further oxidation it gave picoline-tricarbonic acid, of which the 
formula is CgHyN(CO,H)3. Now the C-atoms oxidised by the 
breaking down of the 16-carbon atom flavenol into 11-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,HgN . C,Hi(N Hy) 
C,,H,N . C.H,(OH) 
C, HN . CeH;. 
From this it appears that flavaniline 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 
of the reaction, acetanilide, in the first place, becomes trans- 
formed into the isomeric orthoamidoacetophenone :— 
CH, 
Bec, eee 728 
C,H;.N.C:0O 6 “NH, 
Acetanilide. Amidoacetophenone. 
By the condensation of two molecules of the amidoaceto- 
phenone with the elimination of two molecules of water, flay- 
aniline would be produced in a manner analogous to the forma- 
tion of mesitylene by the condensation of three molecules of 
acetone under the influence of dehydrating agents :— 
* T am indebted to this firm for having kindly supplied me with specimens 
of these products for exhibition. 
[August 5, 1886 
[ie 
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