1887.] Contributions to the Metallurgy of Bismuth. 



93 



Bismuth holding 7 - 6 per cent. Lead. 



1st crystallisation gave crystals holding 4*8 per cent, of lead. 

 2nd ,, „ ,, 3"8 „ ,, 



3rd „ „ ;, 0-8 



4th „ „ „ 0-4 



Bismuth holding 11 per cent. Lead. 



1st crystallisation gave crystals holding 5 '5 per cent, of lead. 

 2nd * „ „ „ 2-5 



3rd „ „ 1*0 



Bismuth holding 5 "6 per cent. Lead. 



1st crystallisation gave crystals holding 2*0 per cent, of lead. 

 2nd „ „ „ 0*7 „ „ 



3rd ,, „ under 0'5 ,, „ 



Bismuth holding 5'3 per cent. Lead. 



1st crystallisation gave crystals holding 1*8 per cent, of lead. 



2nd „ „ „ 0'6 



3rd „ ,, under 0'5 ,, ,„ 



Having attained this point, I worked upon several large quantities 

 of metal — with practically the same results — finally succeeding by a 

 continuation of the process in eliminating every trace of lead. 



By the above it will be seen that the process becomes an ex- 

 ceedingly simple one, large quantities being treated at one time, 

 involving little or no loss, and occupying hours, instead of possibly 

 weeks. 



To illustrate the facilities of the separation of lead and bismuth 

 alloys, I give the following figures from metal holding originally five 

 per cent, of lead. 



10,675 lbs. produced, in the course of six to seven crystallisations, 

 0306 lbs. of available bismuth, the residue 1188 lbs. holding 40 per 

 cent, of lead, so that from a quantity of nearly 5 tons of bismuth and 

 lead alloy only about half a ton remained, holding practically the 

 whole of the lead ; the bulk of the bismuth separated by simple crys- 

 tallisation holding traces only of lead, which, if necessary, could be 

 readily eliminated by further crystallisation. From these facts it is 

 apparent that the separation of these two metals can be effected by 

 turning to account their relative fusing points. 



