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of writhing cobra—the logs now consisting of very much more animal than vegetable matter. Prickly 
tea-tree* logs were also in a similar condition. Tallow-wood is here considered to be the most resistant 
timber to cobra. 
Prickly tea-tree is considered at Kempsey to resist cobra better than turpentine, and at Laurieton 
we were shown small piles for a boat-wharf made of prickly tea-tree which had been down fifteen years, 
and which were quite sound. What the particular local conditions were in these cases we do not know, 
but, while we readily admit the high resistant power of prickly tea-tree, we frequently observed it riddled 
by cobra. 
Anywhere within the influence of the tides on our coastal rivers and creeks, timber is attacked by 
cobra, and there is the most abundant and most convincing evidence that cobra is more injurious in tidal 
watei’s than in pure salt water. 
In the northern rivers of this Colony, a reason why the effects of the cobra are so disastrous is 
doubtless because of the increased warmth of the water, which favours the growth of the pest. 
The following appear to us militate against the growth of cobra :— 
1. Pure salt water. 
2. Fresh water. 
3. Foulness of water. 
Mr. C. W. Parley (late Engineer of Harbours and Rivers) writes to the Forest Department:— 
“ In pure sea water I have reason to believe that the redwood of turpentine will resist the Teredo for 
many years (I can speak for twenty years at least), but when there is some fresh water mixed with the 
salt water, as up rivers, I find the worm will go through and destroy turpentine piles within a year in 
some cases.” 
Piles are more or less attacked in pure salt water, as witness the case of the piles at Coff’s Harbour, 
Wallis Lake, etc. While cobra may flourish in clean sea water, the case of piles in the polluted waters of 
parts of Sydney Harbour is not a fair test of the resistance of timber to cobra. 
A punt working in salt water may subsequently pass over muddy flats, which scrape off everything. 
The punt is all right in fresh water, in which cobra cannot, of course, live ; hence the variation in the, 
reports in regard to the resistance of turpentine to cobra. In examining specific instances of reputed 
resistance to cobra, we often find the circumstances very complex, and we are often without sufficient data 
to compare them.f 
VII.—Turpentine Substitutes. 
It occurred to us that perhaps the different reports as to the durability of turpentine might, in a 
measure, be owing to the substitution of some other timber ; accordingly throughout the trip we kept this 
matter under notice. 
We found on inspection of forests the true turpentine ( Syncarpia laurifolia), also the brush or 
bastard turpentine ( Rhodamnia trinervia) growing side by side, the latter bearing, in the Hawkesbury 
district, a strong resemblance to the former in colour of timber and bark. In no other part of the Colony 
visited by us have we seen the resemblance so strong. The leaf of the brush turpentine is readily known 
by its three prominent veins or nerves. 
As, however, but a very small proportion of the turpentine timber used in public works in the 
Colony has come from this district, and finding no evidence to show that the brush turpentine was in use 
as a substitute for turpentine, also that it rarely if ever attains pile size among the northern rivers, we do 
not now attach much importance to the matter. 
Brush tui-pentine in the Port Stephens and Manning River districts never seems to attain any size, 
but always accompanies true turpentine. 
“ Melaleuca stypkelioid.es. 
+ Since the above was written an excellent paper has been published by Mr. C. ITedley, entitled “ The Marine 
Wood-borers of Australasia and their work” (Proc. Aust. Assoc. Adv. Science, viii, 237, Melbourne, 1900), which is full of 
useful information. 
