182 H. G. SMITH. 
colony, and it is probable that this species is not the only 
one in which this yellow substance exists. As my work on the 
Eucalypts proceeds, it appears that although well marked indi- 
vidual substances continually present themselves, yet, I have little 
doubt but that some system will be found to run through the 
whole of them. That there are characteristic chemical groups 
has long been known, but although aromadendrin, for instance, 
does not appear to exist as such in those trees belonging to the 
Renanthere, yet this yellow substance and aromadendrin resemble 
each other very much in some respects. The similarity of the fine 
hair-like crystals from both these bodies when obtained from 
boiling water is most marked, yet no difference whatever between 
them can be detected under the microscope; they both give 
similar products of decomposition in fused alkali; their reactions 
with reagents are similar; their dyeing properties are also similar, 
but aromadendrin does not give crystalline compounds with mineral 
acids in boiling acetic acid, and thus according to the researches 
of Mr. A. G. Perkin,’ does not belong to the quercetin group, as 
that reaction appears to be characteristic of the group of the 
natural non-nitrogenous yellow mordant dye-stuffs at present 
known to exist, of which quercetin forms the type. 
I purpose naming this yellow crystalline substance obtained 
from these leaves Myrticolorin, as I think it is the first natural 
dye-stuff from our colonial Myrtacee which promises to have a 
commercial future. 
1. Tue Saccwarine Exuparions, 
From the results of this research we may consider that the 
white saccharine exudation from Z. punctata is almost identical 
in composition with the ordinary and well known Eucalyptus 
manna, and may be considered representative of the material on 
which the whole of the previous investigations have been carried 
out. It consists very largely of the sugar raffinose or melitose, 
and also contains a small quantity of reducing sugars, its solution 
1 Journ. Chem. Soc., 1896, p. 1489 &e. 
