216^ Itoj/al Society. 



Esq. J John Lindley, Phil. D, ; John William Luhbock, Esq., M.A. j 

 Rev. George Peacock, M.A. j William Hasledine Pepys, Esq. ; Rev. 

 Adam Sedgwick, M.A. 5 William Henry Smyth, Capt. R.N. ; Wil- 

 liam Henry Fox Talbot, Esq. 



December 8, 1836. — A paper was read, entitled, *' Inquiries re- 

 specting the Constitution of Salts. Of Oxalates, Nitrates, Phos- 

 phates, Sulphates, and Chlorides." By Thomas Graham, Esq., F.R.S. 

 Edin., Professor of Chemistry in the Andersonian University of 

 Glasgow, Corresponding Member of the Royal Academy of Sciences 

 of Berlin, &c. Communicated 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 between 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 a'ora 

 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. 



The author then proceeds to apply these principles to the analy- 

 sis of the oxalates; and 1st, of the oxalate of water, or hydrated 

 oxalic acid; 2ndly, of oxalate of zinc; 3rdly, of oxalate of magnesia; 

 4thly, of oxalate of lime; 5thly, of oxalate ofbarytes; 6thly, of 

 oxalate of potash; 7thly, of binoxalate of potash; 8thly, of quad- 

 roxalate of potash; 9thly, of oxalate of ammonia; lOthly, of oxalate 

 of soda; llthly, of binoxalate of soda; and lastly, of the double 

 oxalates, such as, 1st, oxalate of potash and copper ; 2ndly, oxalate 

 of chromium and potash ; 3rdly, oxalate of peroxide of iron and 

 potash ; and 4thly, of oxalate of peroxide of iron and soda. 



In the second section he treats of the nitrates; and 1st, of hy- 

 drated nitric acid, or the nitrate of water ; 2ndly, of nitrate of cop- 

 per J 3rdly, of subnitrate of copper; 4thly, of nitrate and subnitrate 

 of bismuth J 5thly, of nitrate of zinc; 6thly, of nitrate of magnesia; 

 and 7thly, of supposed double nitrates and supernitrates. He con- 



• See Lend, and Edinb. Phil Mag., vol. iii. p. 451. 



