SACCHARINE AND ASTRINGENT EXUDATIONS OF GREY GuM. 179 > 
through an opening in the bark. It is well known that in some 
of our Eucalyptus timbers objectionable portions are found, known 
as “gum veins”; these are usually seen following the annular 
rings, and are more or less distinct and symmetrical. 
Now, why is it that there is no record of manna being obtained 
from any of the Eucalypts belonging to the Renanthere? The 
kinos of this class of Eucalypts, as far as examined (always 
excepting HZ. microcorys), and I have examined most of them, all 
give a kino entirely free from either eudesmin or aromadendrin, 
and it appears that it is only those trees that can produce manna,’ 
the kinos of which contain one or the other of these bodies. This 
fact is far reaching, and is being followed up as the results may 
be of some commercial importance. 
A product allied to aromadendrin. 
Although our knowledge is fairly complete as to the constituents 
of the exudations or kinos of the Renanthere, yet, our information 
concerning the occurrence of eudesmin, aromadendrin, or like 
bodies in other portions of the trees belonging to this group, is 
somewhat meagre. Of the Eucalypts belonging to the Renanthere 
I can speak definitely as yet only of Z. macrorhyncha. I have 
found that the yellowish crystalline einer: existing in wank! 
large quantities in the leaves of ha, is in 
allied to aromadendrin obtained from some e Eucalyptus kinos, and 
more directly to the group of natural col 
to which quercetin and morin belong. That a seallsine calvaring 
matter existed in the leaves of #. macrorhyncha was known as 
long ago as 1887, it being announced by Mr. J. H. Maiden to 
this Society during that year.’ 
At that time I interested myself in the preparation of a pigment 
from it, and obtained a yellow-lake of some promise. A water 
colour was obtained by precipitating an alkaline solution with 
baric hydrate, drying the precipitate and grinding it with gum- — 
eu ae eas 
1 E. viminalis and E. Gunnii both give turbid kinos in cold water. 
* Proc. Roy. Soc. N. S. Wales, Vol. xx1., p. 252. 
