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XII. Additional Experiments and Observations on the Appli- 
cation of Electrical Combinations to the Preservation of the 
Copper Sheathing of Ships, and to other purposes. By Sir 
Humphry Davy, Bart. Pres. R. S. 
Read June 17, 1824. 
X have already had the honour of communicating to the 
Royal Society the results of my first researches on the modes 
of preventing the chemical action of fluid menstrua, such as 
saline solutions, or sea water containing air, on copper, by 
the contact of more oxidable metals. 
For some months I have been engaged in a series of new 
experiments on this subject, so important to the navigation 
and commerce of the country : and through the liberal and 
enlightened views of Lord Melville, and the Lords of the 
Admiralty, who desired the Commissioners of the Navy 
Board and of the Dock Yards to give me every assistance 
in their power, and all the facilities which our magnificent 
Naval establishments at Chatham and Portsmouth furnish, I 
have been enabled to conduct my operations upon a very 
large scale. At this advanced period of the session, it will 
be impossible for me to give more than a very short notice 
of experiments which have been tried under a great variety 
of circumstances, and the details of which would occupy 
some hours in reading ; but I cannot deprive myself of the 
pleasure of stating the satisfactory and conclusive nature of 
