ll baie 
TRANSACTIONS OF SECTION B. 715 
platinum. When heated in vacuum the Sprengel pump was attached at the end 
nearest the platinum so that the vapour could be drawn over the platinum. 
The heating was in each case continued for some hours. After careful cooling 
the boat with platinum alloy was weighed. 
Cadmium.—V apour carried by hydrogen. 
In one experiment *6832 of platinum absorbed ‘6872 of cadmium. 
This alloy corresponds almost exactly to the formula PtCd,. It is white and 
crystalline and very brittle when heated to fullredness in a vacuum tube. Scarcely 
any cadmium sublimed from it. The loss in weight was inappreciable. Its relative 
weight was found to be 18:53 (at 15°), and the calculated weight for an alloy of 
this composition is 13:59. 
In nitric acid some of the platinum is dissolved along with the cadmium. The 
same product was given by heating the metals together in a vacuum tube. 
Zine in Hydrogen.—The action was slower than with cadmium. 
In one experiment 45°57 per cent. zinc was taken up. PtZn, requires 
40 per cent. Zn. On heating this 45°57 per cent. alloy for two hours in a vacuum 
tube some zine distilled off, leaving a residue containing 44 per cent. Zn. 
It was now heated until the glass tube began to give way, the pump keeping 
upavacuum. The residue after about four hours contained 24-45 per cent. Zn. 
‘This is nearly PtZn, which requires 25 per cent. Zn, It seemed hopeless to get 
more zinc driven off in glass tubes. 
The alloy is crystalline and extremely brittle. It dissolves in acids pretty 
much like the cadmium alloy. 
Heated side by side in the vacuum the alloy of PtZn seemed to be formed, but 
the process was very slow, the zinc vapour not travelling very far. 
Magnesium.—This was the most difficult, as at the temperature employed the 
magnesium vapour is almost entirely absorbed by the glass of the tube and by the 
porcelain boat. 
Some magnesium was distilled in vacuum. This was placed in a porcelain 
boat lined with MgO. The platinum was placed as close as possible and the 
whole heated until the magnesium was melted. A gentle current of very dry 
hydrogen was then kept up for some hours, An extremely friable crystalline alloy 
was produced, From the amount absorbed it corresponds very nearly to the formula 
PtMg,. 
Palladium.—The experiments with this metal and cadmium and zinc have so 
far failed to give any result. Very little cadmium seems to be taken up by 
palladium either when heated in vacuo or in a current of hydrogen. What little 
is taken up distils away very easily. It is possible to keep a piece of palladium 
foil for two hours in cadmium vapour without change. There is a little more 
tendency for zinc to alloy, or be absorbed. 
Nickel behaves very like palladium in this respect. Some electro-deposited 
nickel foil was heated for several hours in cadmium vapour without appreciable 
change in weight. 
These experiments are being repeated. 
1l. Action of Acetylic and Benzoylic Chlorides on dried Copper Sulphate. 
Sy Professor W. R. E. Hopaxinson and Caprain Leauy, &.A4., 
Ordnance College, Woolwich. 
These experiments were undertaken to ascertain whether there would be any 
ground for considering copper sulphate monohydrate as an acid body. The ratio 
of magnesium dissolved to copper deposited from a solution of copper sulphate 
(Clowes) suggested such a nature. 
Pure copper sulphate in fine powder was dried for a week at 98° C. An 
analysis showed that it contained exactly 1 molecule water. ‘ : 
Weighed quantities of this salt were submitted to the action of acetylic 
chloride, firstly by dissolving the chloride in metaxylene, and agitating this with 
