259 



The mixed crude oils of all the samples had specific gravity at 15 C. = 

 0-929; refractive index at 20 = 1-4745, and was soluble in 2 volumes 70 per 

 cent, alcohol. The saponification number for the esters and free acid was 8-4. 



On rectification, 2 per cent, distilled below 172 C. (corr.). Between 

 172-176, 23 per cent, distilled; between 176-186, 32 per cent, came over; 

 between 186-268, n per cent, distilled, and between 268-289, 27 per cent, 

 distilled. These fractions gave the following results : 



First fraction, sp. gr. at 15 C. = 0-9025; rotation D -- 1-0. 

 Second ,, ,, ,, = 0-9079; ,, inactive. 



Third ,, = 0-9132; D + 1-4. 



Fourth ,, ,, ,, = 0-9564; ,, not taken. 



The cineol, determined by the phosphoric acid method in the oil distilling 

 below 186, was 52 per cent., indicating about 30 per cent, in the crude oil (O.M.). 



Myrticolorin. The leaves of E. macrorhyncha contain a large amount 

 of a yellow dye material, discovered by one of us in 1897. (Proc. Roy. Soc., N.S.W.) 

 It was there named Myrticolorin. Its chemistry was afterwards described in a 

 paper (Journ. Chem. Soc., 1898, p. 697). It is a glucoside of quercetin, having the 

 formula C 27 H 30 O l6 and on hydrolysis breaks down into quercetin, glucose, and 

 rhamnose by the following reaction : C 27 H 30 O l6 + 3 H 2 O = C I5 H IO O 7 + C 6 H I2 O 6 + 

 C 6 H I4 6 . 



Osyntrm, Viola-quercetin and Rutin, are analogous substances. Myrti- 

 colorin gives colours, when mordanted, resembling those obtained similarly with 

 the better qualities of flavin, and decidedly purer than those given by quercitron 

 bark itself, or with fustic. The colours are quite fast to light and to milling. 

 The extraction of myrticolorin from the leaves of this Eucalyptus is exceedingly 

 simple, but it is important that the leaves be ground to a very fine powder. When 

 the powdered leaves are boiled and filtered boiling hot, the myrticolorin passes 

 with the filtrate, but crystallises out again on cooling, as it is very slightly soluble 

 in cold water. The tannins and other bodies extracted at the same time remain in 

 solution, and can be removed by filtration ; the myrticolorin can then be washed 

 with cold water, pressed, dried, and powdered. A determination, on a semi- 

 commercial scale, gave at the rate of 8| Ibs. of dried myrticolorin from 100 Ibs. 

 of powdered leaves, collected as would be done for commercial oil distillation. 

 Eucalyptus macrorhyncha is a common tree in New South Wales and Victoria, so 

 that there is an abundance of material available. 



The presence of this dye material in the leaves of E. macrorhyncha at once 

 distinguishes it from E. Icevopinea, and is another illustration of the value of 

 chemical evidence in determining differenced between Eucalyptus species closely 

 allied morphologically. Traces of this dye have been detected in the leaves of 

 other species, but, so far, the amount has not been determined. It may be found 

 eventually, however, that E. macrorhyncha does not give the maximum yield of 

 this dye material, particularly as the leaves of some species become quite yellow 

 when dry. 



