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tive place having its own particular pole, the revolving motion of 

 which is regulated by some general but hitherto unknown law. 



May 16, 1833. 



HIS ROYAL HIGHNESS THE DUKE OF SUSSEX, K.G., 

 President, in the Chair. 



A paper was read, entitled, " Note on a Paper by Dr. John Davy, 

 entitled, ' Notice on the Remains of the recent Volcano in the Medi- 

 terranean.' " By Charles Daubeny, M.D., F.R.S., Professor of Che- 

 mistry in the University of Oxford. 



From the circumstance that azotic gas is frequently evolved from 

 thermal springs, the author infers that this phenomenon is in some 

 way connected with volcanic action j and this he considers to be the 

 case in the instance observed by Dr. Davy, although referred by him 

 to the decomposition of atmospheric air during putrefaclive processes 

 going on at the bottom of the sea. Dr. Daubeny offers objections to 

 the theory of that gas rising to the surface in consequence of the high 

 temperature to which it has been subjected. He conceives that the 

 air which Dr. Davy examined cannot have beer/ derived, from sea- 

 water, but must have originated from the atmosphere itself, with 

 which the volcano communicated. The author is disposed to attach 

 great importance to the accurate examination of the gases given out 

 by warm springs, and recommends the prosecution of the inquiry. 



A paper was also read, entitled, " Experimental Researches on 

 Atomic Weights." By Edward Turner, M.D., F.R.S. Lond. and Edinb., 

 Professor of Chemistry in the University of London. 



This paper is a continuation of the Essay, by the same author, on 

 the Composition of the Chloride of Barium, which was published in 

 the Philosophical Transactions for 1829. Having shown that the 

 atomic weights current among British chemists, though in some in- 

 stances correct, or tolerably approximative, have, as a whole, been 

 adopted on insufficient evidence, he proceeds, in this paper, to give 

 an account of the experiments he has made to ascertain the equivalent 

 numbers for lead, chlorine, silver, barium, and nitrogen. Finding, with 

 reference to lead, that the method adopted by Berzelius did not afford 

 uniform results, he endeavoured to ascertain the quantity of subsul- 

 phate of lead which given weights of metallic lead and the protoxide 

 of that metal respectively produce. He details the mode he employed 

 for the conversion of metallic lead into the subsulphate by a mixture 

 of nitric and sulphuric acids, diluted with an equal bulk of water, and 

 the precautions he adopted to avoid loss. The mean of three expe- 

 riments gave 146*375 grains of sulphate of lead for 100 grains of 

 metallic lead. By the mean of four experiments, Berzelius had ob- 

 tained, instead of the former number, 146-419. Dr. Turner adopts 

 the mean of the whole, namely, 146-41. By prosecuting this inquiry, 



