296 Professor Anderson on the 



On the Colouring Matter of the Rottlera tinctoria. By 

 Thomas Anderson, M.D., F.R.S.E., Regius Professor of 

 Chemistry in the University of Glasgow. 



The colouring matter of the Rottlera tinctoria has long 

 been an article of commerce in India, and is still farmed by 

 Government, being in considerable demand among the Ma- 

 hommedan population for dyeing silk. No attempts have as 

 yet been made to introduce it into European commerce, an im- 

 pression appearing to have existed that the supply is too 

 limited to make it of importance. Dr Cleghorn of Madras, to 

 whose kindness I owe the specimen examined, assures me that 

 this impression is unfounded, and that very considerable quan- 

 tities might be obtained, if it were likely to prove useful ; and 

 the trials I have made with it are sufficient to show that it 

 really merits the attention of silk-dyers. Of its chemical 

 composition very little is known, the only person who has as 

 yet examined it being Solly, and even he appears to have done 

 no more than substantiate the fact that the colouring matter 

 is extracted by alcohol, and has the character of a resin. 



The Rottlera tinctoria is a large tree, which is stated by 

 Roxburgh* to be confined to the mountainous districts of the 

 Northern Circars. Subsequent researches, however, have 

 shown that it is very widely distributed over the uhole Indian 

 Peninsula, from Ceylon to the north-west provinces ; and Dr 

 Cleghorn has found it very abundantly in the hill jungles of 

 Mysore, Canara, and Malabar, from whence large supplies 

 might easily be obtained. The bazaar price of the colouring 

 matter, during the years 1847-8, ranged from 5 to 7 rupees 

 per maund of 25 lbs. 



The fruit of the Rottlera tinctoria is about the size of a pea, 

 and is covered externally with curious stellate hairs and 

 coloured glands, which are easily rubbed off, and then form a 

 red powder, which, without further preparation, forms the ar- 

 ticle of commerce. Similar red glands are found, though in 

 small numbers, on the leaves. The root is also said to be 

 used in Bengal as a dye, but Dr Cleghorn has never heard of 

 its employment in Mysore. The colouring matter, as it 



* Coromandel Plants, vol. ii., p. 160; and Flora Indica, vol. iii., p. 827. 



