32 ME. B. R. WATSON ON 



manjista-dyed cloth, I also dyed cloth mordanted for Turkey-red 1 by boiling for two 

 hours in water along with its own weight of manjista. The cloth was afterwards 

 finished as in Turkey-red dyeing, viz., by steaming and brightening. The shade 

 obtained was orange-red only of medium fullness , although every effort had been made 

 to obtain a really full shade. 



Catechu. — This material is apparently scarcely used by the native dyers. 



A European method was employed for dyeing. Catechu was dissolved in dilute 

 acetic acid (10 per cent.) and filtered from insoluble impurities. Cotton cloth was padded 

 with this solution so that 10 per cent, (reckoned on weight of cotton) of catechu was 

 on the cloth and dried. It was then passed through hot potassium dichromate solution 

 ( 10 per cent, reckoned on weight of cotton) rolled up and left for several hours; 

 afterwards washed and dried. A light to medium brown shade was obtained by this 

 method and by repeating the whole process once a full shade was obtained. 



Red Sandal. — This material is apparently not used as a dye in Bengal. 



Cotton cloth mordanted with tannin and red spirits was boiled with raspings 

 of the wood suspended in water for 30 minutes. The bath was kept in constant 

 motion. A medium red shade was obtained. 



Padauk. — This wood is chiefly grown in the Andamans and is not used as a 

 dye-stuff. On account of its similarity to red sandal wood I attempted to dye with 

 it in the manner described for red sandal. On cotton a medium brownish red shade 

 was obtained. 



Synthetic Dyes used for comparison with the Indigenous Dyes. 



The following considerations were kept in mind in deciding which synthetic dyes 

 to use for comparison : — 



(1) To use dyes of which the fastness had been already exactly determined and 

 recorded. These could then be conveniently used as standards. 



(2) To use dyes which would, singly, give tints to match the dyeings with indige- 

 nous materials. 



(3) To use well-known dyes representative of the more important groups of syn- 

 thetic dyes. 



Those selected were : — 



Eosin. 



Congo-red. 



Primuline developed with /?. Naphthol. 



,, ,, ,, Resorcin. 



,, ,, ,, Phenol. 



Magenta. 

 Safranine. 

 Alizarine. 



1 Mordanted according to instructions issued by Badische Anilin und Soda Fabrik using Method 

 111(a) 1. in pamphlet " Alizarine Colours on Cotton," A. 815. c. 



