VEGETABLE DYES IOI 
viz. Alizarin (the dyeing principle of madder), about 
1870, and Indigo blue in 1870. 
The triumph of the chemists brought with it the 
usual penalties of progress. The madder industry of 
Southern France quickly succumbed before its formid- 
able competitor, and whole districts were ruined. The 
indigo planters of Natal and Bengal answered the 
challenge in a different way. They studied their plant 
more intensively, undertook breeding and hybridisation 
experiments, and succeeded in materially increasing the 
efficiency of production. 
At the present time the whole trade in vegetable 
dyes is faced with a similar problem. Even where, as 
in the case of logwood and the red woods, the natural 
dye principle has not actually been synthesised, numer- 
ous substitutes of practically equivalent value may be 
prepared ; so that the most pressing object for inquiry 
is whether there is now any justification for the survival 
of the natural dye industries, or whether the. land 
bearing dye plants could not be more usefully employed 
in other ways. 
Before the question can be intelligently considered, 
a survey must be made of the most important natural 
dyes and their sources. 
It is easy to approach the subject under a misappre- 
hension. The wonderful brilliance and diversity of 
colour shown by flowers and foliage would naturally 
lead us to hope that we could borrow some of their 
magnificence. But the pigments elaborated by plants 
for their own decoration are fugitive and elusive sub- 
stances, closely knit with the life of the organism, and 
all these are quite useless as dyes. 
