a New Class of Salts. 281 



in specimen IV. we have the same remarkable increase in 

 carbon as observed in the barium salt ; the sodium is to the 

 carbon as 1 : 5^, which is exactly the proportion found in the 

 latter salt; but this excess of carbon does not go down with 

 a silver salt made from it. / 



Examination of the Silver Salts made from the altered Nitro- 

 prussides. 



24. To save unnecessary repetition, the numerous analyses 

 made of the silver salts are here brought together, although 

 it might have been more distinct to have introduced them 

 under the respective salts from which they were made. The 

 reason for converting them into silver salts was, that from the 

 high atomic weight of silver and its accuracy of determination, 

 the atomic accordance or disagreement between it and the 

 iron could more readily be perceived. 



Analyses I. II. and III. were made on three different pre- 

 parations of silver salt made from three different specimens 

 of crystallized nitroprussic acid, by adding the latter to nitrate 

 of silver. 



Analysis IV. was made upon a portion of II. treated on 

 sand-bath with strong nitric acid in the hope of dissolving out 

 the excess of iron. A very small quantity of iron was detected 

 in solution by prusside of potassium. 



Analysis V. was made on the silver salt prepared from cry- 

 stallized nitroprusside of ammonium. 



Analyses VI. and VII. from silver salt precipitated from 

 crystallized nitroprusside of barium, which contained 17'96 

 grs. of carbon, or in which the barium was to the carbon as 

 1 • 5i 



Analysis VIII. On previous silver salt digested on the 

 sand-bath with strong nitric acid to dissolve out excess of 

 iron. 



Analysis IX. On silver salt made from the crystallized 

 sodium salt (No. 2) containing J9'91 grs. carbon. 



Analysis X. Silver salt prepared from sodium salt (No. 4) 

 containing 21*59 carbon, or in which the sodium was to the 

 carbon as 1 : 5|. In order if possible to remove the excess 

 of iron, the salt was first precipitated by sulphate of copper 

 and washed, the copper salt was now decomposed by soda 

 and crystallized, and the silver salt was precipitated from this 

 newly-crystallized portion. 



I. 19*605 grs. gave S?? grs. Fe'^ O^ and 12-86 grs. Ag CI. 

 II. 16-795 grs. gave 3-24 Fe^O^ and 10*94 Ag CI. 



III. 13-580 grs. gave 2-60 Fe^O^ and 8*79 Ag CI. 

 IV. 6-765 grs. gave 1-35 Fe^ O^ and 4-355 Ag CI. 



Phil. Mag. S. 3. Vol. 36. No. 243. April 1 850. U 



Vw 



