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 ; 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 ray 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. 



A. Scott. 



RemarJcs 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 



