CHAPTEE XI 



DYE STUFFS AND TANNING SUBSTANCES 



Indigo. Ten years ago this was a very large industry in 

 the central parts of the valley of the Ganges in India, and it is 

 still of minor importance there, in Java, Guatemala, and other 

 countries, but the history of the old madder industry of the 

 south of France is repeating itself with regard to indigo. This 

 dye stuff can now be well and cheaply produced by artificial 

 means, and the competition of the great German dye factories 

 is proving too much for the planters, in spite of the facts that 

 considerable improvements have been introduced, and that the 

 natural dye is still better than the artificial. 



A considerable number of species of indigo, Indigofera 

 leptostachya, sumatrana, tinctoria, Anil, and others, are used, 

 and they are grown as annual crops, forming small bushes to 

 about three feet high. The dye does not exist in the plant as 

 such, but arises through oxidation, and when the plants are cut, 

 they are steeped in water for about twelve hours, and then the 

 mass is agitated for a few hours till oxidation has fully occurred, 

 when the dye stuff is formed in large quantity. 



Recently, when it was almost too late to do anything, a 

 certain amount of attention has been given to the scientific 

 side of indigo cultivation and manufacture in India, but it does 

 not seem probable that much can be done to resuscitate the 

 industry against the competition of the artificial dye. Java, 

 where scientific treatment was begun sooner, seems to be 

 suffering less from the German competition. A combina- 

 tion of countries interested in indigo is required for proper 

 investigation and other measures. 



