THE ENTOMOLOGIST. 369 
in danger of falling ; and, in like manner, the piles supporting 
the Trinity chain-pier, at Leith, were—in 1825, four years 
only after its erection—so perforated as to be useless, and 
were removed at a great expense, and replaced by new ones: 
the girth of the original timbers was forty-eight inches, 
which, before removal, was reduced tg six inches. Various 
plans for remedying the mischief were tried, but none 
succeeded so well as covering the whole surface of the 
timber, from the bottom of the sea to within a foot or two of 
mean high-water mark, with broad-headed iron nails, techni- 
cally called scupper nails, set close together. A piece of 
wood, covered on three of its sides with these nails, was 
found to have the whole interior eaten away, such portion of 
the exterior only being left as had been penetrated by the 
nails. This plan was adopted, at an expense of about £1000, 
in the Leith pier, which had cost £30,000; and, after four 
years, it was ascertained that none of the piles thus protected 
had been penetrated by the Limnoria. Timber used for 
partially-submerged structures is now generally kyanized, 
and this process greatly retards, if it does not totally prevent, 
the injury occasioned by this insect. The third, and most 
formidable timber-borer, is the Teredo, the character of which 
truly curious animal seems to have been as familiar to the 
ancients as to ourselves. Ovid compares this insidious enemy 
to the corroding effects of care on man,— 
“ Estur ut occulta vitiata teredine navyis;” 
the simile is as good as the description of the Teredo is 
perfect. The interest in this mollusk has been kept up to the 
present hour, and it has been made the subject of three most 
elaborate and learned treatises in one year, 1833: they were 
by Pierre Massuet, Jean Rousset and Godfrey Sellius, the 
last of whom wrote a quarto volume of three hundred and 
sixty pages, and cites the labours of two hundred previous 
authors. ‘Three years previously to the publication of this 
elaborate work, the Teredo threatened to submerge Holland, 
and hence the intense interest taken in its history. Holland 
seems to have been considered, at that period, a country 
standing on piles; and it is not astonishing that when the 
piles were found to be giving way a panic should have set 
in. It is rather remarkable that the three greatest historians 
