On the Union of Copper with Iron, &c. 109 



to cover the crucible wel], as in the former experiments ; the 

 produce was a lump of copper, in the heart of which a head of 

 steel (containing a proportion of copper) was found inclosed, 

 with some loose bits of steel, on the surface of which a few grains 

 of bad copper were to be perceived. The copper was very mal- 

 leable, but not so much so as when unadulterated, and containing 

 only 44 per cent, of iron. 



The formation of the steel may of course he accounted for by 

 the crucible being filled witli charcoal, to prevent the oxidation 

 of the copper. 



Although the union of these two metals is certainly not so 

 perfect a,5 that of other metals, yet I trust that those who credit 

 these simple experiments will abandon the prejudice of there be- 

 ing any impossibilitv in their combination. For my own satis- 

 faction, I have made several experiments in uniting copper with 

 other metals ; and perhaps you may consider them sufficiently 

 interesting to give them also a place in your pages. What more 

 particularly struck my attention, was the eifect of arsenic when 

 melted with copper. It altered the colour without increasing the 

 weight of the copper, being no doubt \'olatilized. 



United with two hundredth parts of arsenic, the copper was 

 rendered whiter, softer, and more ductile, but not increased in 

 weight. United with ten hundredth parts of arsenic, the copper, 

 as in the former case, was not increased in weight, but became 

 very white, and not quite so malleable. 



It mav he necessary however to observe, that I used the glass 

 or oxide of arsenic, which might have facilitated its evolution; al- 

 though, as the crucibles were filled with charcoal dust, I thought 

 this would have prevented any such eifect. 



Copper united with two hundredth parts of tin was rendered 

 less malleable, became of a flaky bright when suddenly flattened 

 by hammering, was smooth in tlie fracture, and had a colour in- 

 clining to yellow, and somewhat whitened. 



Copper united with two hundredth parts of lead assumed a 

 bright flaky aj^pearance when hammered, and the malleability 

 was much diminished. 



Copper united with two hundredth parts of zinc was rendered 

 softer and less ductile, but not so flaky as when united with 

 either tin or lead : the fracture was of a dirty- red colour. 



I shall shortly have the [)leasure of submitting to your notice 

 the result of my experiments on the combination of some other 

 metals. I remain 



Your respectful and obliged servant, 



P. N..IoilNSOiV, 

 Ma^flcn-iane, Wooc!-»tP(.'Ct. Mineralogist and Assiijwr. 



XXVII. On 



