SOME MIXTURES OF CAST IRON AND NICKEL. 109 
in the crucible. When cast into ingots after the second 
melting the nickel had not the appearance of a pure metal, 
but exhibited a dull fracture, as if fine sand or particles of 
earth had been mixed with the crystals, showing the pre- 
sence of impurities which it would be almost impossible to 
get rid of. It remained, therefore, a question for consi- 
deration whether the results would be different if nickel, 
properly prepared and of greater purity, were employed. 
To clear up doubts on this point a mixture of pure nickel 
with No. 3 Pontypool iron was made, but the result was a 
bar of white silvery metal, which broke when the weight 
of 798/bs. was laid on, as will be seen by referring to the 
Tables above. 
I obtained from London a number of other bars, con- 
sisting of iron and nickel, which on being submitted to 
the same tests as before, gave better results than those 
obtained in the previous experiments when nickel pre- 
pared from the ore was employed. 
The results obtained from this second series of bars 
are given in the following table: 
