a New Class of Salts. 279 



IV. V. 



1st Crystallization. 2nd Crystallization. 

 Iroh .... 14-96 14*55 



Barium . . . 3323 33-60 



Carbon . . . 15-41 1638 



Hydrogen . . 0*83 055 



Another portion, in flat prismatic crystals, made by neu- 

 tralizing nitroprussic acid with carbonate of barytfes, gave the 

 foUowmg results : — 



12-33 grs. gave 6-61 grs. sulphate of barytes aiid 2-42 grs; 

 peroxide of iron. 



6*60 grs. gave 4*005 grs. carbonic acid and 1*040 gr. water. 



VI. 



Iron 13-73 



Barium 31-53 



Carbon 16*52 



Hydrogen 1*75 



In this case the salt lost no more in the water-bath, although 

 this was to have been expected from its larger quantity of 

 hydrogen. 



In all these cases the specimens were excellently crystallized, 

 and yet there is a greater or less quantity of a foreign sub- 

 stance pi-evailing in all, and producing results so very dis- 

 cordant. In the first two portions analysed the barium is to 

 the carbon (37*01 : 17*79) almost exactly as 1 equiv. : 5^ equivs., 

 and the iron is to the carbon, sensibly though not so exactly, 

 in the same proportion. In analysis VI., the iron is to the 

 carbon as 28 : 33*7} or rather more than I : 5|, while the 

 barium is to the carbon as 1 : 6. Again, in analyses IV. and 

 v., the iron is to the carbon as 1 : 5, and the barium to the 

 same element 1 : 5|. 



Finally, it will be seen further on that the silver salt hiade 

 from these altered salts of barium do not contain this excess 

 of carbon. The filtrate from the silver salts yields on evapo- 

 ration and incineration a small quantity of a black ash, but 

 the quantity being so small the nature of the substance could 

 not be ascertained. We can scarcely suppose that it is a 

 ferrocyanide, because we should have expected to have it 

 precipitated by nitrate of silver, even though it could not be 

 recognized by its usual tests. It would be useless without 

 further information to speculate upon the probable nature of 

 the impurity. Sufficient however has been shown to prove 

 that the most complicated results may attend the analysis of 

 specimens of nitroprusside of barium prepared from solutions 

 which have been heated and thus partially decomposed. 



