204 Miscellanies. 
more or other alloy can enter into it now than did a hundred years 
ago. The London copper is by some preferred to the Liverpool, 
and many think the American is better than any other 5 but there is 
no great difference, all wear out in a surprisingly short space of time. 
In former times our vessels were all iron fastened, now they are 
fastened with copper ; because it has been found that the copper de- 
stroys the iron, but may it not be that the same galvanic action pre- 
served the copper ? 
I saw lately in the Philosophical Hall at Rotterdam a simple exper- 
ment, which, in my opinion, went far to illustrate this theory: A long 
strip of copper was bent snakelike (as in the annexed figure, ) into five 
or six loops or bights each of which was immersed in a separate vase of 
sea-water,—a small piece of iron was riveted to the end of the copper 
in the first vase,—after remaining there five or six months, the water 
in the first vase was slighily tinged with red, that in the second had a 
shade of blue’scarcely perceptible, in the third it was green, in the 
fourth a very dark olive, and in the last it was almost black. At the 
top of the water in each glass there was a bit of cotton-wick, wound 
loosely round the copper, to give, as I imagined, more surface for the 
action of the air and water, and there the corrosion was the greatest, 
and in proportion’ to its distance from the iron. 
As I am rather out of the way of chemical researches, it is possible 
that this idea may be trite to you, but if you should find it worth your 
while to try the experiment and follow it to some higher result, it 
might lead to some improvements in the manner of sheathing ships 
which would be of essential. interest to our merchants. 
. Scorr. 
Remarks by the Editor —There can be no doubt that the sugges- 
tions of Capt. Scott, as to the cause of the protection of the copper, 
in the experiment which he saw at Rotterdam, are correct. The iron 
