ESTIMATION OF SULPHATES. CREIGHTON. 



209 



chloric acid, contained one gram per litre ; or 1 cc. was equiva- 

 lent to one milligram of the metal. 



The precipitation of the sulphate was carried out at 100 C., 

 and the precipitate was allowed to digest in the hot (80 90 C.) 

 liquid for three or four hours before filtering. 



The results given in the following tables are the means of 

 three analyses. 



The experimental error in this work is 0.0008 grams. 



In the first table are given the results obtained by adding 

 various amounts aluminium chloride solution to 50 cc. of 

 ammonium sulphate solution. 



TABLE 1. 



The second table gives the results obtained by adding a 

 constant volume of aluminium chloride solution to different 

 volumes of ammonium sulphate solution. 



