194 TIMBER AND TIMBER TREES. [ CHAP. 
a state of decay even while the outer portions are in full 
vigour. A tree under these conditions, the inner portions 
comparatively dry, and the outer full of sap, shipped at 
once to a hot climate like that of India, or to such a variable 
one as that of England,very naturally bursts from unequal 
shrinkage, being also exposed to very great changes of 
temperature. To obviate this peculiarity and apparent 
defect, let the Jarrah be fallen when the sap is at the 
lowest ebb, and flitched as previously suggested.’’* 
I have seen it stated in some correspondence from 
Western Australia that a specimen of Jarrah timber has 
been chemically examined by Professor Frankland, with 
the view to ascertain whether there is any peculiar acid 
or other substance present in it calculated to resist the 
attacks of the Teredo navalis. It does not appear, how- 
ever, that anything of the kind has been found which 
could be credited with the effect referred to. It is 
believed by the Professor that the singular immunity 
from attack which this wood enjoys is due either to the 
odour or taste it possesses. These, though by no means 
remarkable or repugnant to the human senses, are pro- 
bably strongly so to the Teredo navalis.+ 
* The Committee of Lloyds have recently had the subject of Jarrah 
under their consideration, and determined to class this timber with those in 
line 3, Table A, of the Society’s rules ; thus ranking it with Cuba Sabicu 
Pencil Cedar, &c., for the construction and classification of ships, ; 
+ A late Western Australian almanack says: ‘* None of the neighbouring 
colonies possess timber of a similar character to the Jarrah, or endowed 
with equally valuable properties. If cut at the Proper season, when the 
sap has expended itself and the tree is at rest, it will be found the most 
enduring of all woods, On this condition it defies decay ; time, weather 
water, the white ant, and the sea-worm have no effect upon it, Sneciiiene 
have been exhibited of portions of wood which had been nearly thirty years 
partly under water and partly out. Others had been used as posts, and for 
the same period buried in sand, where the white ant destroys ffi a few 
weeks every other kind of wood. For this peculiar property the Jarrah is 
