C26 On a Mass of Native Iron found in Brasil. 



different method. Apiece of the iron weighing fifty grains 

 having been dissolved in nitro-nniriatic acid, the solution was 

 evaporated to dryness. Ammonia was then added, and the so- 

 lution again evaporated to dryness, in order that the oxide of 

 iron miglit bs rendered more dense, and more easily separated 

 from the solubb portion. A fresh addition of ammonia then 

 readily dissolved the nickel, and the solution after filtration ap- 

 peared of a deep-blue colour. 



A small quantity of sulphuric acid having then been added, 

 the whole was again evaporated not merely to dryness, but with 

 sufficient heat to expel the excess of ammonia, muriate of am- 

 monia, and sulphate of ammonia. The remainder was sulphate 

 of nickel, which was then redissolved in Vv'ater, and after being 

 suffered to crystallize, weighed S'6 grains. Having found by 

 experiment previously made for that purpose, that ten grains of 

 nickel give 44 grains of sulphate of nickel, I infer that S'G of 

 the sulphate correspond to 1-95 of metallic nickel, which is 

 nearly 4 per cent, of the quantity of native iron taken for ex- 

 periment. 



By an analysis conducted in a similar manner on 23 grains of 

 the scaly Hakes of oxide brought home by Mr. Mornav, from 

 the spot where the mass was found, I obtained 3-1 grains of sul- 

 phate of nickel, vvhich correspond to 7"05 nickel, amounting to 

 no more than 3-i)6 per cent, of the oxidated crust taken for 

 analysis. But, if we consider the weight which 100 parts of the 

 metallic alloy v.-oukl acquire by oxidation, we shall find the two 

 experiments corregpond with a degree of accuracy that may oc- 

 casion more reliance to be placed on these experiments than 

 they really deserve. 



f)() parts of iron in the state of black oxide will be 

 combined with 28*3 oxygen 

 and 4 nickel will take 



about 1-1 oxygen, 



so that 129*4 of the crust will contain only four parts of 



metallic nickel, and 100 ditto will contain 3-1, which scarcely 

 exceeds the quantity actually found by trial. 



From the presence of nickel in this mass we cannot but re- 

 gard it as liavinfT the same meteoric origin with the various 

 other specimens tiiat have before been found ; and although in 

 the spot vvhence it had been first removed, Mr. Mornay disco- 

 vered a bed of matter from which it appears, by analysis, that 

 cimilar iron might be formed by art, it seems by far more pro- 

 bable, that an opposite change has really taken place, and that 

 the whole of this supposed ore is the result of progressive oxi- 



diition> 



