28 MR. 15. R. WATSON ON 



Such is the evidence at present available as to the fastness of the natural dyes of 

 Bengal. It is, to a great extent, self-contradictory and throughout there is a want of 

 precision indicated by the use of such expressions as "moderately fast," " very fugi- 

 tive," &c. , &c. I have, therefore, attempted to supplement the available evidence, and, 

 as the result of a series of systematic observations and quantitative determinations, 

 to make precise and numerical statements as to the fastness of the more common of 

 these dyes. 



Part I. — Dyeing on Cotton. 



List of Natural Dyes examined. 1 



Turmeric {Curcuma longa). 



Kusum or SafHower (Carthamus tinctorius). 



Bakam {Ccesalpinia sappan). 



Palas (Butea frondosa). 



L,atkan (Bixa or el' ana). 



Al (Morinda tinctoria). 



Manjista (Rubia cordi folia). 



Catechu {Acacia catechu). 



Red Sandal {Pterocarpus santalinus). 



Padauk {Pterocarpus dalbergioides). 



The dye-stuffs lac and kamala, which have been used in the second part of this 

 investigation, viz., on silk-dyeing, are apparently unsuitable and never used for cotton 

 dyeing. 



Methods employed for dyeing with these materials. 



As will be seen from the following details I have, in all cases, attempted to dye by 

 one or more methods reported to be used by the native dyers. 



In some cases I have been unable to produce dyed specimens by following the 

 methods described. This may be due to one of several causes : — 



{a) The descriptions of the methods are not in all cases detailed, e.g., frequently 

 the quantities of the materials required are not mentioned, and, in the absence of 

 specific directions, I may not have been able to exactly reproduce the methods used 

 by the native dyers. 



{b) The reports of the methods employed (N. N. Banerjee, loc. cit. ; H. W. 

 McCann, loc. cit.) have generally been supplied by men without any special technical or 

 chemical knowledge (district officers of the Civil Service) and frequently are by no 

 means first-hand reports, and at each reproduction errors have probably crept in. 



1 These materials were all obtained in the Calcutta bazaars , with the exception of Al. I must here 

 thank Babu Bipin Behari Das, Research Student, Civil Engineering College, Sibpur, for his assistance 

 in collecting these materials. 



