a New Class of Salts. 219 



The analysis of the dried salt was made by decomposing it 

 with sulphuric acid, and estimating the two metals as oxides, 

 after separating them by sulphuretted hydrogen. 



I. 22*24 grs. gave 6*325 grs. oxide of copper and 6'515 per- 



oxide of iron. 



II. 21*00 grs. gave 0*018 CuO and 6*120 Fe^O^. 



The combustions were made with chromate of lead and 

 with oxide of copper. 



I. 8*100 grs. gave 0*230 gr. water and 6'3'13 grs. carbonic 

 acid. 



II. 7-977 grs. gave 0240 HO and 6*217 CO^. 



III. 9*887 grs. gave 0*330 HO and 7*694 CO^. 



IV. 11*507 grs. gave 0*320 HO and 8*936 CO^. 



The nitrogen was determined in three different ways. 



I. Dumas' quantitative method : — 



6*226 grs. gave 98 CC. nitrogen gas. Barom. 30'105 inches. 

 Therm. 8°*8 C. 



II. Bunsen's method : — 



Vol. 



Vol. mixed gases (moist) , 246*3 

 Vol. after absorption (dry) 121*1 



Corrected vol. of mixed gases 



Corrected vol. of nitrogen . 



Corrected vol. of carbonic acid . . 75*689 

 Hence the proportion of nitrogen to carbonic acid is 

 1 : 1*593, which calculated on the mean quantity of carbon 

 (21-25), yields 31*12 per cent, nitrogen. 



III. Liebig's method: — 

 Tubes, Vol. m[xed gases. Vol. after absorption. Vol. of carbonic acid. 



80 13-2 



91 13-3 



10'4 15'6 



8*2 13*5 



10*6 17*7 



6*7 11-2 



8*2 14*0 



1'5 12*3 



8*0 12*0 



9*0 13*7 



10*8 17*2 



7-3 1 1-9 



5*4 9*2 



284*0 109*2 174*8 

 Hence the proportion of nitrogen to carbonic acid is 1 : 1 -60. 



