THE TEREDO AND ITS DEPREDATIONS. 555 



Flessingue, the pieces of oak, pine, and red fir, were found intact, while 

 those unprepared were perforated. In the month of October, of the 

 same year, the pieces of creosoted pine and fir at Harlingen showed a 

 perfect state of preservation. At Harlingen the treated and untreated 

 pieces were fastened together ; the teredo penetrated the latter, but 

 had not touched the creosoted wood. The same was true of the creo- 

 soted wood exposed at Stavoren, when visited in 1859. 



At Nieuwendam, in March, 1859, three pieces each of oak, pine, and 

 red fir, all creosoted at Amsterdam, were exposed in the sea. They 

 were examined in September of the same year. They had been fast- 

 ened together by cross-pieces of unprepared wood : it was found that 

 the teredo had penetrated, at the juncture of these cross-pieces, even 

 into the creosoted wood, and that sometimes he stopped immediate- 

 ly beneath the surface, at others he penetrated to a depth of several 

 millimetres ; in the oak, he worked his way into the interior through 

 those parts of the surface which were not in contact with the unpre- 

 pared wood. 



Experiments with creosote-oil were recommenced in July, 1860, 

 with ten pieces each of oak and red fir, following the plan indicated in 

 paragraph 5 ; the localities chosen were Nieuwe-Diep and Stavoren ; in 

 the latter place the pieces which remained intact the previous year 

 were again placed in the water after their surface had been removed 

 by the adze. Still later, in August, 1861, a further trial was made 

 at these same places with pieces of pine, beech, and poplar, sent to 

 the commission by Mr. Boulton, and prepared at his works in 

 London. 



All these pieces were examined toward autumn in 1862, 1863, and 

 1864 ; while the unprepared pieces, placed near the others as counter- 

 proofs, were found each year filled with teredos, one could not discover 

 any traces of the teredo in the creosoted pieces except in the oak creo- 

 soted at Amsterdam ; in cutting these, it was found that the creosote 

 had penetrated them very imperfectly. 



A third examination, in 1864, showed that all the pieces prepared 

 by Mr. Boulton, and which had been exposed in the sea since August, 

 1861, were entirely intact ; the most careful examination could not 

 show the slightest trace of the worm, even in the pieces withdrawn from 

 the water in 1862 and 1863, and each time scraped to a depth of several 

 millimetres and again placed in the water. They resisted the attacks 

 of the teredo perfectly. 



An equally favorable and decisive result was obtained from the 

 pieces of fir creosoted at Amsterdam. Notwithstanding they had been 

 exposed in the sea since July, 1860, during five consecutive summers, 

 nothing could be discovered which resembled the galleries of the tere- 

 do : one of the pieces, at a point where the color of the wood indicated 

 an insufficient penetration of the creosote-oil, showed a very slight 

 worm-eaten appearance; but the absence of the calcareous deposit, and 



