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Proceedings of the Royal Society 
water mark to the bottom. This discovery caused no little surprise 
and regret, as engineers had always looked on greenheart as proof 
against destruction by marine insects ; but being the first, and it 
was hoped perhaps an isolated instance, I did not consider it neces- 
sary at once to r ecord the fact. 
I have since, however, received a specimen of timber taken 
from one of the piles in the steamboat pier at Salen, in the Sound 
of Mull, which was erected four years ago, the main piles being 
made of sound greenheart, and I find that in this locality also the 
Limnoria has commenced to perforate the timber. 
In both of these instances sufficient time has not elapsed to 
allow the wasting to make great progress, but in both cases the 
perforations have penetrated into what is unquestionably sound 
fresh timber ; and, therefore, this result conflicts with certain other 
experiments, such as those made at the Bell Bock, where the 
greenheart remained nearly sound after nineteen years’ exposure. 
The joint paper of Dr Maclagan and Dr G-amgee on greenheart 
in the “ Society’s Transactions ” states that by subjecting green- 
heart wood to a process identical with that used for the extraction 
of sulphate of bebeerine from the bark , a product is obtained pos- 
sessed of an intensely bitter taste, and not differing perceptibly 
from the sulphate of bebeerine. This may account for wounds pro- 
duced by a splinter of greenheart not readily healing. 
I am also disposed to think that it is to the existence of this alkaloid 
in the timber, and not to its hardness, that its undoubted power of 
withstanding in certain cases and for a certain time the action of 
the Limnoria is due, and it would be interesting to discover whether 
the wasted portions of greenheart at Wick and Salen produced 
bebeerine in a smaller degree as compared with sound timber. It 
is possible, as suggested by Sir Kobert Christison, that long pro- 
tracted immersion in sea-water may so counteract the preservative 
principle due to the bebeerine in the timber as to render it open 
to attack. It is also possible that the greenheart now imported in 
such large quantities has degenerated like the “ Crown Memel,” 
which, it is well known, cannot be procured of the same high 
quality as formerly. Change of soil, moreover, affects the growth 
of trees, and is perhaps sufficient to account for the great variations 
in the quality of foreign grown timber. 
