the presetvation of metals by electro-chemical means. 341 
made a voyage to Nova Scotia, and returned in January 1825. 
A false and entirely unfounded statement respecting this vessel 
was published in most of the newspapers, that the bottom was 
covered with weeds and barnacles. I was present at Ports- 
mouth soon after she was brought into dock : there was not 
the smallest weed or shell-fish upon the whole of the bottom 
from a few feet round the stern protectors to the lead on 
her bow. Round the stern protectors there was a slight 
adhesion of rust of iron, and upon this there were some 
zoophytes of the capillary kind, of an inch and a half or two 
inches in length, and a number of minute barnacles, both 
Lepas anatifera and Balanus tintinnabulum. For a con- 
siderable space round the protectors, both on the stern and 
bow, the copper was bright ; but the colour became green 
towards the central parts of the ship ; yet even here the rust 
or verdigrease was a light powder, and only small in quan- 
tity, and did not adhere, or come off in scales, and there had 
been evidently little copper lost in the voyage. That the 
protectors had not been the cause of the trifling and per- 
fectly insignificant adhesions by any electrical eft'ect, or by 
occasioning any deposition of earthy matter upon the copper, 
was evident from this — that the lead on the bow, the part 
of the ship most exposed to the friction of the water, con- 
tained these adhesions in a much more accumulated state 
than that in which they existed near the stern ; and there 
were none at all on the clean copper round the protectors in 
the bow ; and the slight coating of oxide of iron seems to 
have been the cause of their appearance. 
I had seen this ship come into dock in the spring of 1824, 
before she was protected, covered with thick green carbonate 
