1822.] Mr. Mill on Carburet of Nickel. 20t 



A small portion of oxide of iron is found in the Bath Waters^ 

 where hkewise it is accompanied with sihca ; nor is it improba- 

 ble that this earth is in many cases the cause of the oxide 

 of iron being dissolved in the water ; and these facts combined 

 furnish us probably with an explanation of the manner in which 

 ochre is generated. As to what may be the effect of the com^ 

 bination of oxide of iron and sihca on animal bodies, it is the 

 province of medical men to examine, and to determine upon, 

 after long and adequate experiments. 



Article X. 



On the Formation of Carburet of Nickel, and Method of obtain- 

 ing the Metal pure. By Mr. Nicholas Mill. 



(To the Editor of the Annals of Philosophy.) 



SIR, London, Nov. 16, 1821. 



Little being known relative to nickel and its compounds, 

 particularly of the formation of the carburet which was first 

 glanced at by Dr. Thomson in a paper on the purification of this 

 jiietal, inserted in the Annals of Philosophy y the originality of 

 which was lately laid claim to by two individuals in two late 

 papers in the same pubhcation, I have taken the liberty of for- 

 warding to you the following process : 



Let the native arseniuret or sulphuret of nickel be finely 

 pounded and mixed with charcoal also pounded, and placed in a 

 flat bottomed crucible, and exposed to a dull red heat for two 

 tours. Blow off the charcoal with a pair of bellows, and dis- 

 solve the nickel in nitrosulphuric acid. Evaporate and crys- 

 tallize. Beautiful green crystals of the form of a square solid 

 will be obtained. Let these be carefully selected, dissolved in 

 water, recrystaUized, and mixed with a small portion of borax 

 and pounded charcoal, and fused for a quarter of an hour in a 

 strong red heat. When cold, break the crucible, and under- 

 neath the borax will be found a button with a very high degree 

 of lustre, very fusible and magnetic, which latter fact proves its 

 freedom from arsenic,"^ from which substance, by other pro- 

 cesses, it is very difficult to free it. The carburet thus formed 

 is brittle and fusible, and if exposed to the flame of the oxyhy- 

 drogen blowpipe becomes malleable ; but it may still, and most 

 commonly does, contain copper and iron. In order, therefore, 

 to obtain the malleable metal pure, dissolve the carburet Iq 

 nitric acid, neutralize the solution, and precipitate by aqueous 



* Chcnevix; Richter. 



