58 PRESIDENT’S ADDRESS—SECTION B. 
of Dresden, contains an oxygenated substance (a ketone 
C,.H,,07) which imparts to it its pleasant lemon-like odour, 
and several other species of eucalyptus yield oils of a similar 
odour, probably due to the presence of similar substances. 
References to these will be found in Mr. Maiden’s book, to which 
T have already referred. It is obvious that there is still abundant 
room for investigation in the direction indicated, an investigation 
too which has the additional merit of possibly leading to 
important practical results, some of the substances obtained 
having been highly spoken of as perfumes, while some, we know, 
possess considerable disinfecting power. 
There are many other Australasian plants, besides the 
eucalyptus, the leaves of which yield essential oils, but scarcely 
any of these have received more than an imperfect examination, 
and here again is a wide field for work. 
I may mention also here that some years ago I succeeded in 
getting a hydrocarbon, apparently a terpene of boiling point 
156° C., from New Zealand kauri gum by passing steam over the 
roughly-powdered gum heated in a copper vessel. It would be 
interesting, perhaps, to re-examine this in the light of Wallach’s 
researches, but up to the present time I have had no opportunity. 
Leaving the essential oils, and passing to other classes of pro- 
ducts, we find that Lucalyptus viminalts yields the well-known 
“manna.” This has been lately shown by Tollens to contain over 
50 per cent. of vaffinose, or melitose, one of the more recently 
investigated, and from a scientific point of view, more interesting 
sugars, containing as it does at least eighteen atoms of carbon, 
and yielding a mixture of levulose and galactose on treatment 
with dilute acids. I believe, though on this point Iam not quite 
certain, that “manna” has also been found on other species of 
eucalyptus ; if so, it would be well worth examining. 
The alkaloids aftord us a field almost untouched, so far as exact 
chemical investigation is concerned. So far as I know the only 
substances belonging to this class, which have been at all care- 
fully examined, are those to be found in the bark of <A/stonza 
constricta and the “‘fituri.” Of the former several have been 
isolated and partially described by different observers, but 
especially by Hesse, who describes at least four; but all of them 
need further examination, especially as some, at any rate, possess 
very marked physiological activity. The alkaloid to which the 
peculiar eftects of “ Azturi” are due has been isolated by Professor 
Liversidge, who describes it as a volatile liquid possessing 
characteristics closely allied to but distinct from those of nicotine. 
and having the formula C,H,N. This also needs further 
examination, but sufficient quantities of material are very difficult 
to obtain, and I understand Professor Liversidge has not had an 
opportunity to continue the investigation. There are numbers of 
plants which seem to contain principles of more or less poisonous 
