264 G. J. BURROWS AND E. E. TURNER. 



Found : Ba 26*0, Fe 10*6, 2 O 4 49*6 per cent. 

 NH 4 Ba[Fe(C 2 4 ) 3 ], 3 H 2 requires: Ba 26'0, Fe 10*6, 2 O 4 

 49*9 per cent. 



The sodium, potassium, and ammonium salts are readily 

 obtained from the barium salt by treating the latter with 

 the appropriate sulphate, and were found to crystallise 

 with five, three, and three molecules of water respectively. 



The salts of ferrioxalic acid are green in colour, and 

 with the exception of the barium salt are very soluble in 

 water giving solutions which are quite stable in the dark. 

 On exposure lo bright light these salts, even in the dry 

 state, are decomposed giving amongst other products, 

 ferrous oxalate. In addition to these salts, iron gives rise 

 to another series of oxalate derivatives, the ferro-oxalates, 

 which arecharacterised by a yellowish colour both in solution 

 and in the solid state. In this connection, it is interesting 

 to note that ferrous oxalate, unlike most ferrous salts, is 

 yellow in colour, and although insoluble in water, the solu- 

 tion formed by treatment with dilute sulphuric acid is 

 yellow, similar to that of the ordinary Fe (C 2 4 )" 2 ion, the 

 depth of colour increasing as the solution is gradually 

 neutralised by ammonium hydroxide or other alkali. This 

 suggests the possibility that so-called ferrous oxalate is not 

 a simple salt, Fe C 2 4 2 H 2 0, but probably a ferrous ferro- 

 oxalate, Fe [Fe(0 2 4 )], 4H 2 0. 



Barium ferrioxalate was used as the starting point for 

 obtaining certain alkaloid salts whose preparation was 

 undertaken with the intention of endeavouring to resolve 

 a ferrioxalate into its active components. Although 

 satisfactory results were not obtained in this connection, 

 it is interesting to note that since the completion of this 

 work this resolution has been effected through the phenyl 

 ethyl ammonium salt (Thomas, J.O.S. 1921, 119, 1140), this 

 worker having failed to effect a resolution through the 



