119 

 OITAPTER IX. 



DYES AND TANNING MATERIALS. 



The greatest development in the direction of dyes has 

 not been towards those of vegetable origin. On the 

 contrary, for the last twenty or thirty years vegetable dyes 

 have been gradually displaced by the advances of chemical 

 science in utilising coal-tar, and in the artificial preparation 

 of colouring matters to supersede the old vegetable dyes. 

 In this direction we need but refer to the serious blow given 

 to the trade in Persian berries (Rhamnus infectorius) in the 

 Levant by the discovery of the Aniline dyes, or to the more 

 recently threatened substitution of chemically - prepared 

 Indigo for that of vegetable origin. So alarming did this 

 discovery seem to be to the indigo-planters in India that 

 we cannot refrain from quoting the following paragraph 

 from a letter of Professor Armstrong published in the Kew 

 Report for 1880. He says : — " Notwithstanding the number 

 of operations involved in the manufacture, it is stated that 

 it will be possible thus to produce indigo at such a price 

 that it can even enter into competition with the natural 

 article, and that by substituting the method of dyeing pre- 

 viously described for the troublesome and somewhat un- 

 certain indigo vat method, there will be a still more distinct 

 advantage gained over the natural article. It is difficult at 

 present to estimate the influence which this discovery may 

 have on the production of Indigo in India; but when it is 

 remembered, to take an analogous case, that the discovery 

 of a process of manufacturing madder red was only made in 

 1869, and that now it is almost impossible to procure natural 

 madder red or garancine, the annual value of the imports of 

 which into the United Kingdom alone for the years 1859 to 

 1868 amounted to about X1,000,000 sterling, it is difficult 



