484 AUSTRALIAN NATIVE PLANTS. 
Professor Abel ‘made an analysis of Jarrah timber, and as 
this analysis is often referred to in different pamphlets on the 
subject, I give it 27 extenso :— 
“In accordance with instructions received, I have made a 
qualitative analysis of certain specimens of Jarrah, with the view of 
obtaining from its chemical composition actual proof of the 
principle which renders the timber impervious to the action of dry 
rot, and proof against the action of Zeredo navalizs and the white 
ant. I find that the duramen contains from 16 to 20 per cent. of 
an astringent gum somewhat resembling the gum-kino of com- 
merce, sparingly soluble in alcohol, but completely so in boiling 
distilled water. Upon further analysis, this gum was found 
to consist almost entirely of colouring matter and a highly astrin- 
gent vegetable acid, which may be called “ Jarrah-tannic acid,” 
inasmuch as it possesses some of the characteristics of tannic-acid, 
together with other relations peculiar to itself. 
“JT have failed to discover an alkaloid or organic base 
(although several different. processes have been adopted), since, 
after the separation of the gum, albumen and colouring matter; 
I obtain nothing more than traces of saccharose and glucose with 
fatty matter, which in the present enquiry are of little or no im- 
portance. It is, therefore, evident that the active principle of the 
Jarrah is the powerfully astringent acid, which, uncombined with 
any base, is suspended in the gum, and thereby uniformly diffused 
throughout the tissues of the wood in a thin section, of which 
innumerable translucent particles of the gum may be seen by the 
aid of a small convex lens.” 
Bearing in mind the almost unanimous opinion as to, the 
immunity of Jarrah from attacks by the Zeredo navalis, one is 
inclined to think that the writer of the following (from Port 
Darwin) must have been mistaken as to the Eucalyptus timber of 
which the piles to which he refers were made :— 
‘“‘Jt would appear that the Jarrah is just as susceptible to the 
attacks of Cobra (Zeredo navalts or ? Calobates sp.) in water as it 
is to those of white ants on shore. The Whampoa, on her 
southern trip, took down a piece cut from one of the trial piles of 
the jetty (Port Darwin), planted some months ago, which was 
