I 376 ] 



XXXV. On the Effect of Centnfuging certain Alloys while in 

 the Liquid State. By J. Joly,' F.R.S., and J. H. J. Poole, 

 B.A.I* 



DURING- the course of the experiments described in 

 the previous paper as to the effect of centrifuging 

 liquid lead, certain alloys were also dealt with. The results 

 obtained are appended. 



It will be seen that in the case of the silver-lead alloys no 

 definite separation could be obtained. The silver-lead alloys 

 were specially dealt with, as, if silver and lead could be 

 separated by centrifuging, the process might perhaps be 

 cheaper and more expeditious than the existing cupellation 

 method. Unfortunately the method appears to be a failure, 

 at least with the velocities we were able to employ. 



In the case of all the other alloys an undoubted separation 

 was effected. In all cases, there is a considerable difference 

 in density between the constituents of the alloy, and no very 

 large amount of separation was effected. It is of interest 

 that a definite alloy like lead-tin alloy, which is of the 

 composition PbSn, should be capable apparently of being 

 separated by the action of the centrifuge. 



Silver-Lead Alloys. 

 W 

 B* 



Exp. Composition. ( *■ s Eesult. 



Bottom. Top. 



XIII Pb 97 per cent. 3-3761 3*3746 Positive. Top bullet about 



Ag 3 „ „ 0-045 per cent, lighter. 



XVIII. ... Pb 95 per cent. 3*3937 3*3947 Negative. Top bullet about 

 Ag 5 ,, „ 0'03 per cent, denser. 



XXI Pb 90 per cent. 3*3892 3-3833 Positive. Top bullet about 



Ag 10 ., ,, 0*17 per cent, lighter. 



XXIV. ... Pb 90 per cent. 3*3922 3*3923 Negative. Top bullet about 



Ag 10 „ ,, 0*003 per cent, denser. 

 Other Alloys. 



XIV Pb 63*6 per cent, 2*8308 2*8129 Positive. Top bullet about 



Sn 36*4 ,, „ 0-63 per cent, lighter. 



XXVI. ... Ditto. 2-8530 2*8114 Positive. Top bullet about 



1*5 per cent, lighter. 



XX Pb 82 per cent. 3*0594 3-0328 Positive. Top bullet about 



Sn 18 ,, „ 0-9 per cent, lighter. 



XXV Ditto. 3-1078 3-0519 Positive. Top bullet about 



1*8 per cent, lighter. 



XIX Pb 32 per cent. 2*9979 2*9679 Positive. Top bullet about 



Sn 16 ,, „ 1 per cent, lighter. 



Bi 52 „ „ 



Iveagh Laboratory, 



Trinity College, Dublin. 



* Communicated bv the Authors, 



