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PROCEEDINGS 



OF 



THE ROYAL SOCIETY. 



1836. No. 28. 



December 8, J 836. 



FRANCIS BAILY, Esq., V.P. and Treas., in the Chair. 



Charles Mackenzie, Esq., who at the last Anniversary had ceased 

 to be a Fellow from the non-payment of his annual contribution, 

 was, at this meeting, re-admitted by ballot into the Society, agree- 

 ably to the provision of the Statutes. 



A paper was read, entitled, " Inquiries respecting the Constitu- 

 tion of Salts. Of Oxalates, Nitrates, Phosphates, Sulphates, and 

 Chlorides." By Thomas Graham, Esq., F.R.S. Edin., Professor of 

 Chemistry in the Andersonian University of Glasgow, Correspond- 

 ing Member of the Royal Academy of Sciences of Berlin, &c. Com- 

 municated by Richard Phillips, Esq., F.R.S. 



The results which the author had obtained from his former expe- 

 riments, and of which he communicated an account to the Royal 

 Society, suggested to him the probability that the law with re- 

 spect to water being a constituent of sulphates, would extend also 

 to any hydrated acid and the magnesian salt of that acid. As he 

 had already found that the sulphate of water is constituted like the 

 sulphate of magnesia, so he now finds the oxalate of water to re- 

 semble the oxalate of magnesia, and the nitrate of water to resem- 

 ble the nitrate of magnesia. His researches render it probable that 

 the correspondence bet ween water and the magnesian class of oxides 

 extends beyond their character as bases; and that in certain subsalts 

 of the magnesian class of oxides, the metallic oxide replaces the 

 water of crystallization of the neutral salt, and discharges a func- 

 tion which was thought peculiar to water. In the formation of a 

 double sulphate, the author finds that a certain degree of substitu- 

 tion or displacement occurs ; such as the displacement of an atom 

 of water pertaining to the sulphate of magnesia, by an atom of sul- 

 phate of potash, to form the double sulphate of magnesia and pot- 

 ash. The same kind of displacement appears to occur, likewise, in 

 the construction of double oxalates ; and the application of this 

 principle enables us to understand the constitution both of the 

 double and super-oxalates, and to explain the mode of their deriva- 

 tion. 



