NOTES ON MYRTICOLORIN. 379 
and dried, and if desirable powdered. If required it may be 
purified by dissolving again in boiling water before drying and 
treating as before. It is most necessary to powder the leaves, as 
by so doing the extraction is more complete and much quicker, 
and the finer the powder the more satisfactory the yield. When 
whole leaves are boiled, little of the material is obtained. As 
myrticolorin is not very readily soluble in water, even on boiling, 
it will be necessary to use a good quantity of water ; three extrac- 
tions appear to be sufficient to remove the whole of the substance 
providing the leaves are finely ground. , 
(d) That in this product Australia,has a material of great value 
can be readily seen when we consider the commercial importance 
of quercitron bark and fustic. Quercitron bark is worth in 
England £6 10s. per ton, and fustic £4 10s. per ton. The quan- 
titative content of quercetin in quercitron bark has not, it appears, 
yet been determined, but Mr. Perkin thinks it to be about two or 
three per cent., and when we consider the difficulty of grinding 
bark in comparison with dried leaves, and the increased percentage 
of quercetin in the leaves of this Eucalypt, the advantages in 
favour of eucalyptus leaves are apparent. If the yield of quercetin 
is taken at three per cent. in quercitron bark, that equals 67iIbs. 
quercetin per ton, while one ton of dried leaves of Z. macrorhyncha 
would give 224 ibs. of myrticolorin, or over 100 Ibs. of quercetin. 
It appears, therefore, that the prospective value of these eucalyptus 
leaves is very good, and at present they are put to no use whatever. 
Myrticolorin, too, is easily obtained in comparison with the pre- 
parations from quercitron bark. The manufacture of flavin (a 
dried extract from this bark) appears to be somewhat complicated, 
and the use of chemicals must necessarily increase the cost of 
production, while the preparation of myrticolorin can be carried 
out practically without capital, the only outlay necessary beyond 
the utensils usually found upon a small homestead being a mill 
1 Myrticolorin contains seven per cent. of water, it probably cxyetallle- 
ing with three molecules of water. 
