172 Gooch and Osborne — Potassium Aluminium Sulphate. 



upon zinc sulphate. A reasonable excess of the bromide-bro- 

 mate mixture is able in a moderate time to carry the hydrolysis 

 of aluminium sulphate to a fairly definite point corresponding 

 nearly to the removal of five-sixths of the acidic ion, while the 

 iodide-iodate mixture under similar conditions of prolonged 

 action removes practically all the acidic ion. 



Some experiments to test the effect of a mixture of potassium 

 chloride and potassium chlorate indicated that the hydrolysis 

 of aluminium sulphate under otherwise similar conditions is 

 very slight compared with that produced by the bromide- 

 bromate mixture or by the iodide-iodate mixture. 



