Manchester Memoirs, Vol. xlvi. (1901), No. 4. 5 



Both the grey mass and the metallic particles decom- 

 pose water very rapidl}'. In dry air they do not change, 

 but in moist air they rapidly crumble up, forming a white 

 powder, while if heated in a blowpipe flame they first 

 scintillate slightly, but then becoming coated with oxide 

 they suffer no further action, nor are there any signs of 

 fusion. 



In tlic best experiment, the charge consisted of 

 100 grams of barium peroxide, 21 grams of aluminium 

 (these being in the proportion required by the equation 

 3Ba02 + 4Al = 3Ba + 2Al203) together with 25 grams of the 

 product of a previous experiment. The product in this 

 experiment was a very hard, almost black, mass, which 

 however was in parts very rich in crystalline flakes of 

 metal, and also contained some small nodules of metal. 



The metallic part contained 63-3 per cent, barium, but 

 only I9"3 per cent, aluminium, the total being 826 per 

 cent. An analysis in another experiment showed 66-6 

 per cent, barium, 29*3 per cent, aluminium ; total 95^9 

 per cent. 



The analysis of the nodules mentioned above, whilst 

 it gave but 58 per cent, barium, was the only case in 

 which the full 100 per cent, of barium + aluminium was 

 reached ; usually it was impossible to completely separate 

 the flakes of metal from the associated oxide for the 

 purpose of analysis, as the metal was so very brittle. 



These experiments seem to indicate that the reaction 

 is reversible, and that it cannot be used to obtain pure 

 barium, but only an alloy of barium with aluminium 

 containing up to about 60 per cent, barium. 



An endeavour was made to prepare a calcium alloy 

 by this method, but the reaction would not proceed at all. 

 It was also attempted to replace the aluminium by 

 magnesium ; in this experiment, the charge taken was 



