196 LIMNORIA TEREBRANS IN PLYMOUTH HARBOUR. 



drawback to the Magazine, not only from its excluding certain papers 

 which would otherwise gain insertion, but by its preventing the work 

 from taking that rank in scientific literature to which the number and 

 character of its contributors fairly entitle it. We have thought it better 

 to publish the plates in a separate form, rather than to make an altera- 

 tion in the price of the Magazine, intending the purchase of the supple- 

 ment, (after the issue of the first number), to be quite optional with the 

 subscribers. It is proposed to publish about three of these supplementary 

 parts in the course of a twelvemonth, and not in any way to reduce the 

 number of woodcuts in the body of the Magazine. 



SHORT COMMUNICATIONS. 



Limnoria terebrans in Plymouth Harbour. — In my paper on 

 the Teredo and Limnoria (vol. ii. n. s. page 206) I stated that 

 I had submitted Kyanized wood to the test of the action of 

 the Limnoria; accordingly on the 12th of January, 1838, I 

 placed the following pieces of wood on the piles of the Pitch- 

 House Jetty, in Plymouth Dock- Yard, at low water ; a piece 

 of American deal, 4 inches by 10^ thick; also a piece of si- 

 milar dimensions, which had been soaked for two months in 

 a saturated solution of arsenic ; and two others which had 

 been prepared with Kyan's solution, by W. Evans, Esq., the 

 agent of the patentee in this town. On the 12th of the fol- 

 lowing August, the pieces having all been under water for 

 seven months, were taken up by some of the dock-yard men 

 in presence of Mr. Churchward and myself, and they are now 

 in my possession. It was found that the protected pieces 

 had all been acted on, though not to quite so great an extent 

 as the plain piece of deal ; but the specimens were dotted 

 with Balani and Flustrce, and all contained living Limnoria, 

 and it was evident that, though retarded, the destruction of 

 the wood would, in a few months more, have been equally as 

 certain as where none of the above preparations had been 

 employed. 



It appears to me highly improbable that any protection can 

 be afforded in cases of this kind, from the employment of so- 

 luble substances ; for in the instance of the solution of oxide 

 of arsenic, or of the bi-chloride of mercury (corrosive subli- 

 mate), which Kyan's solution is known to be, it is evident that 

 any additional quantity of fluid coming in contact with it, 

 will dilute it, or re-dissolve any of the salt which might have 

 been deposited in the pores of the wood, by drying ; the con- 



