3 
TRANSACTIONS OF SECTION B. 775 
FRIDAY, SEPTEMBER 5. 
The following Reports and Papers were read :— 
1. Report on Isomeric Naphthalene Derivatives. 
[The report is deferred for completion. ] 
, 2. The Development of the Ooal-tar Colour Industry since 1882.! 
By W. H. Perxin, Ph.D., F.R.S. 
In the brief report given, the first development since 1882 referred to was 
that of the synthetical formation of colouring-matters of the para-rosaniline group 
by means of tetramethyl diamido-benzophenone, produced by dimethylaniline and 
_ phosgene gas, and the formation from that body of hexamethyl para-rosaniline, 
; 
e 
La 
Victoria blue, &c., also auramine. Reference was then made to the group of 
phthaleins, as ccerulein, galleine, fluoresceine, and more especially to the beautiful 
new colouring-matter derived from meta-amidophenol and phthalic anhydride, 
rhodamine, its relationship to fluoresceine being shown. The rhodamine derived 
from meta-amidophenol and succinic anhydride was also referred to, In the 
alizarine series it was mentioned that this group of colouring-matters had been 
speedily increasing in consumption, chiefly in the woollen trade, and that the isomer 
of purpurin, anthragallol, made synthetically, had been added to this list of colouring- 
matters. Alizarine blue in its soluble state, when combined with bisulphate of 
sodium, was also more appreciated as a substitute for indigo, Some peculiar deri- 
vatives of alizarine blue, known as alizarine green and alizarine indigo blue, had 
also lately been introduced. For the purpose of producing a great variety of 
shades of grey, slate, drab, olive, brown, black, &c., along with alizarine colours, 
some products not belonging to the alizarine series, such as galloflavine and 
_naphthazarine, had also come into use. Amongst the yellow dyes there have also 
been several additions, as quinoline yellow, and some oxyketones produced from 
benzoic acid and pyrogallol, as ‘alizarine yellow A,’ triovybenzophenone, and 
‘alizarine yellow C,’ which is gallacetophenone. Also tartrazine, a product 
obtained from dioxytartaric acid and phenylhydrazine monosulphonic acid. 
Great improvements have also been made in the preparation of methylene blue, by 
which the yield of colouring-matters has been increased, with a corresponding 
cheapening of its cost. 
With respect to the azo colours, their manufacture has attained colossal pro- 
portions, and their purity has reached a great state of perfection. 
The next series of colouring-matters mentioned was the remarkable class of 
compounds known as substantive dyes—colouring-matters which unite with cotton 
fibre without the intervention of a mordant; the number of these discovered 
during the last few years places at the disposal of the dyer yellow, red, purple, 
fo} 
blue, and other colouring-matters of this class. 
As to the annual value and cost of the coal-tar colouring-matters now made, it is 
found difficult to get a correct estimate. In 1882 it was thought to be about 
3,350,000/. ; but the large increase of weight of colouring-matters produced since 
that time, it was believed, had been fully compensated by a corresponding reduc- 
tion of their selling-price. 
Germany still holds the first position in this industry, though competition of 
Swiss, French, and English manufacturers with that country has been steadily 
increasing. The use of the precise methods of scientific research in this industry, 
especially in Germany, and the consequent improvement in quality and yield of 
colouring-matter, with diminished cost, showed the great importance of manu- 
facturing under these circumstances, and it was hoped that chemical manufacturers 
of this country would profit by their example, and, by having good laboratories in 
® Published in Industries, September 26 and October 3, 1890. 
