70 HENRY G. SMITH. 



From much recent work in this direction it appears prob- 

 able, that the tinctorial influence exercised by the location 

 in the molecule of certain radicles in these natural yellow 

 dyeing materials, will eventually be completely understood. 



Air dried myrticolorin contains 3 molecules of water of 

 crystallisation, and this is not entirely removed until several 

 degrees above 130° O. It also forms a monopotassium 

 derivative O27H27O16K when treated with potassium acetate. 1 

 It also reacts with sulphuric acid, when this is added to a 

 solution in boiling acetic acid, forming salts of quercetin 

 containing one molecule of acid Oi 5 Hi O 7 , H 2 S0 4 . When 

 myrticolorin is decomposed by boiling three hours with 

 dilute sulphuric acid, and allowed to stand about 20 hours, 

 almost the theoretical amount of quercetin (49 '67 per cent.) 

 is obtained. 



The value of quercetin glucosides for dyeing purposes is 

 well known, and the amount of myrticolorin obtained from 

 the leaves of E. macrorhyncha is somewhat large, as 8J /° 

 of dried myrticolorin was obtained commercially from the 

 dry ground leaves. 2 The extraction of the dye material is 

 exceedingly easy, so that myrticolorin may be considered 

 to have good commercial possibilities. 



I would like to express my acknowledgements to Mr. O. 

 Still of this Museum, for much assistance in determining 

 the commercial methods for the extraction of myrticolorin. 



8 Perkin— Trans. Chem. Soc, 1899, p. 440. 



3 See also Journ. Roy. Soc. N.S.W., xxi„ p. 377. 



