GERMAN SCIENCE 111 
the colour industry, also gave an advantage. In other respects, 
the absence of raw material and of large-scale chemical manu- 
facture of such things as vitriol and soda, Germany was at 
a great disadvantage. 
I cannot attempt here to trace the progress of events in any 
detail. Suffice it to say that before long the colour industry 
had taken firm root in Germany and-had begun a growth 
which has been nothing less than stupendous, and has placed 
the nation far before any other in this branch of the practical 
arts. 
Altogether more than 2,000 distinct coal-tar colours have 
been put on the market and the number is constantly being 
added to. I can attempt no survey of them and I will only 
allude to one more in detail, namely indigo. 
Most people know, -I think, that indigo is a blue colouring 
matter of great permanence obtained from a plant which has 
been cultivated to a very great extent in India and used from 
very early times. The value of the indigo exported from 
India in a year has amounted to 43,000,000, 
The preparation of this colour artificially from coal-tar 
naturally soon became a hope and aim of the new industry. 
The chemical nature of the substance was elucidated after 
much labour, and in 1884 Liebig’s successor in Munich, von 
- Baeyer, prepared it artificially. {t soon appeared on the 
market, but did not achieve commercial success. Undaunted 
by this the German chemists, and_ technologists continued 
their efforts, and only after more than fifteen years of pro- 
digious labour and the expenditure of vast sums of money, 
roundly stated at a million sterling, was success finally achieved. 
It was a wonderful display of talent and enterprise; it has 
involved incidental discoveries and industrial innovations of 
great consequence, and is probably as fine an example as 
could be cited of the triumph of scientific skill intensively 
directed toa manufacturing enterprise. In 1897, when Germany 
