THE INDIGENOUS DYES OF BENGAL. 4L 



the range of the synthetic products it would be difficult to find dyes so easily affected 

 by all agencies as turmeric, kusum and palas. Latkan, red sandal and padauk are 

 scarcely worthy of further consideration, as they so readily fade in light. On the other 

 hand the dye-stuffs bakam, manjista and catechu do not rank in the very highest 

 grade along with, say, turkey-red, but they compare very favourably with the great 

 majority of the synthetic products ; and, but for the question of cost, might well 

 hold a prominent place even in the modern scientific dyeing trade. 



There is, further, always the possibility that, by some comparatively slight modi- 

 fication of the dyeing process, the fastness of some of the other indigenous dyes might 

 be very considerably improved. When we recollect that, e.g., in the case of Primu- 

 line developed with /3. Napthol by merely passing the dyed fabric through a weak 

 solution of copper sulphate, we are able to change the fastness to light from I. to III. 

 in our scale (Cotton Dyeing, Messrs. Cassella & Co., p. 93), there seems to remain 

 always at least some ground for hope in this direction. 



