TEREDO NAVALIS IN NOVA SCOTIA — MURPHY. 369 
on wood previously roughened by a toothed instrument; this 
application was two millimetres thick. 
4. Method of M. Ripurjk, analogous to the preceding. 
5. Paraftine varnish, obtained by the dry distillation of peat, 
from the factory of M. M. Haages & Co., at Amsterdam. 
6. Coal tar applied cold on the wood in several successive 
layers, or applied hot on wood whose surface had been previously 
carbonized. Some pieces were treated as follows: Holes were 
first bored in them and filled with tar; then plugs were fitted 
closely to the holes and driven in with sufficient force to make 
the tar penetrate the wood; other pieces still were painted over 
with a mixture of tar with sulphuric acid, or sal ammoniac, or 
turpentine, or linseed oil. 
7. Painting with colours mixed with turpentine and linseed 
oil, among others, with chrome-green or with verdigris. 
8. Singing or superficial carbonization of the wood. 
The pieces of wood thus prepared were placed in the water at 
the end of May, 1859, and the first examination, made toward 
the end of September of the same year, showed that neither of 
these methods afforded any protection from destruction by the 
Teredo. There was one partial exception, and that was the piece 
of wood treated according to No. 6; these showed only traces of 
the Teredo here and there. But at a later examination, in the 
autumn of 1860, when the wood had been exposed a year and a 
half, these were also found to be equally severely attacked by 
the Teredo. 
The results of these experiments strongly convinced the Com- 
mission that no exterior application of any nature whatever, or 
modification of the surface merely, would give any efficacious 
guarantee of protection against the teredo. Even supposing that 
one or another of these means would prevent the young teredo 
from attaching themselves to the wood, yet the constant friction 
of the water or ice, or any accident, might break the surface of 
the wood sufficient to give access to the teredo. 
This seems a proper place to mention a practice in general use 
in Holland for warding off the teredo; this consists in covering 
wood with a coat of mail made of nails. This operation is very 
