816 DR. WALTER ROSENHAIN AND MR. SYDNEY I, ARCHBUTT ON THE 

 variety of zinc, kindly presented by Sir JOHN BRUNNER. The analy S e8 of these 

 materials are as follows :- 



Aluminium- 



Silicon .... 



Iron 



Copper . . 

 Aluminium (diff.) . 



0'17 per cent. 

 0-20 

 Trace. 

 9 9 '6 3 per cent. 



Zinc 



The zinc used contained traces only of iron and 

 silicon, and was of at least 99 '98 per cent, 

 purity. 



The alloys were prepared by melting together weighed quantities of the two 

 metals in salamander crucibles heated in a small furnace. 



For the preparation of the alloys rich in aluminium, that metal was first melted 

 and the requisite quantity of pure ainc added to it, the zinc dissolving very rapidly 



TABLE I. Calculated and Analytically Determined Composition of the Alloys. 



