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Observations on the Action of the Mineral Acids on Copper, 

 under different circumstances. By John Davy, M. D., 

 F. R. S., Physician to the Forces. Communicated by Sir 

 James Macgrigor, Director-General of the Army Medi- 

 cal Board, &c. * 



My Dear Sir, London, December 24. 1829. 



If you think the accompanying paper of any interest, will 

 you do me the honour of publishing it in your Journal. It 

 was written, as you will perceive by the date of it, more than 

 two years ago, and before M. Bequerel had published either of 

 his very important dissertations on the application of feeble 

 electro-chemical powers to produce new combinations. The re- 

 sults contained in my papers are precisely of the same class as 

 those more ingeniously and ably obtained by the French che- 

 mist. The circumstance which principally renders them, in my 

 opinion, deserving of some notice, is the faciUty of making the 

 experiments, no complicated apparatus being required, or any 

 manual dexterity. I am, &c. 



John Davy. 



To Professor Jameson, &c. 



In a paper published in the Philosophical Transactions of 

 1826, I described certain changes which I had witnessed m 

 some' ancient alloys of copper, attributable to the operation of 

 electro-chemical attraction, acting very slowly and in the man- 

 ner of a mineralizing process. 



In this paper I shall describe the results of some experiments 

 which I have been induced to make on the action of the mineral 

 acids on copper, placed in different circumstances, with the 

 hope of illustrating the changes just alluded to, and of obtain- 

 ing a farther insight into phenomena of an obscure kmd and 

 interesting nature, at least in their bearings in relation to the 

 mineral kingdom. 



• This interesting paper, as I observe by a note on the margin, was sent 

 lo England for publication, and reached London in July 1827- 



