442 M. Berzelius on the [JUNB. 



acid from the acetate of lead, was deprived of the excess of 

 lead by means of sulphuretted hydrogen gas, and the oxide of 

 nickel by caustic potash. The oxide thus obtained weighed 

 5*92, which makes 30*8 hundredths of metallic nickel in the 

 ore. 



The general result of the analysis is, therefore, as follows : 



Arsenic 48-06 



Sulphur 19-29 



Nickel 30-80 



Iron 2-99 



Silex 1-00 



102-15 



As the result of so complicated an experiment cannot be sa- 

 tisfactory, I devised another analytical method, as follows : 



(D.) Analysis hy Means of Chlorine. 



A portion of the pulverized ore, previously treated with di- 

 lute muriatic acid, to separate the carbonate of lime, was in- 

 troduced into a bulb, blown in the middle of a piece of baro- 

 meter tube ; a current of chlorine gas, dried over fused chlorine 

 of lime, was made to pass through the tube, and when nearly the 

 whole of the atmospheric air was expelled, the bulb was heated 

 by means of a spirit lamp. The metals and the sulphur com- 

 bmed with the chlorine gas ; the mixture of the muriatic, 

 arsenic, and hyposulphurous acids formed, distilled in small 

 drops, and were collected in water. The less volatile chlorides 

 remained in the bulb. The operation continued for 12 hours; 

 but the evolution of chlorine gas was always very slow ; 

 45*685 parts of the ore were employed. 



(A.) Examination of the Chlorides remaining in the Bulb, 



a. Water was introduced into the bulb ; the yellowish mass 

 did not appear to dissolve at first, and the water dissolved only 

 muriate of iron ; but in an hour, muriate of nickel was also dis- 

 solved, and the water left a residuum of 15-12 parts, which 

 were ore unacted upon.* The gas had, therefore, decomposed 

 30*565 parts. The solution was mixed with nitric acid, and 

 boiled, to convert the iron into peroxide. It was afterwards 

 neutralized by ammonia, and the iron precipitated by succi- 

 nate of ammonia. The succinate of iron, burnt upon a small 

 porcelain capsule, left 1-82 part of peroxide of iron, which, 

 treated with soda by the blowpipe, gave no trace of arsenical 

 odour. This quantity of peroxide is equivalent to 1-26 of me- 

 tallic iron, or 4-1 1 per cent, of the weight of the ore employed, 



• To satisfy myself (hat the portion undissolved by water was not altered, I exa- 

 mined it with a microscope, by which it appeared like small fragments, partially cor- 

 roded. When dissolved in nitromuriatic acid, it gave, with sulphate of barytes, the 

 same quantity of sulphur as the portion decomposed by chlorine. 



