62 On the Alloys of Steel. [1820. 



the equivalent number for nickel to be 28, these quantities are 

 equal to Iron .... 33*69 



Nickel .... 3-56 



37-25 

 Supposing the quantities to be correctly 



Iron .... 33-5 

 Nickel .... 3-5 



"3T 7 " 

 the proportions per cent, are, 



Iron .... 90*54 

 Nickel .... 9-46 



100-00 



A second experiment on 47 grains gave 61 grains of per- 

 oxide of iron =42*57 iron. The ammoniacal solution of nickel 

 was lost by an accident ; reckoning from the iron, the quan- 

 tities per cent, are, 



Iron .... 90-57 

 Nickel .... 9-42 



99-99 



A third experiment on 56 grains gave 73'06 grains peroxide 

 of iron = 50-99 iron, and 5-4 of oxide of nickel = 4-51 nickel; 

 or per cent., Iron .... 91*00 

 Nickel . ". 5 V 8 * 01 

 Loss .... 0-99 



100-00 



The mean of the three gives 8*96 per cent, of nickel. 



The meteoric iron was dissolved in aqua regia, and the iron, 

 thrown down by pure ammonia, well washed, and heated red. 



Jn the first experiment the ammoniacal solution was evapo- 

 rated to dryness, the ammonia driven off by heat, and the oxide 

 of nickel re-dissolved in nitric acid and precipitated by pure 

 potassa, the mixture being boiled a few seconds. 



In the third experiment the nickel was thrown down from 

 the ammoniacal solution at once by pure potassa. The first 

 method is best, for a minute portion of oxide of nickel escaped 

 precipitation in the last experiment, to which the loss is pro- 

 bably to be attributed. 



All the precipitates were heated to redness. J. G, C. 



