Decomposition of Sulphates by Ammonium Chlo- 

 ride in Analysis according to Fresenius. 



By 



Masumi Chikashige, Ri'éakushi, 



College of Science, [raperial Uuiversity. 



The accuracv in all respects of Fresenius' standard treatises on 

 analysis is usually so unimpeachable, that it seems proper to call 

 attention to a misleadino;- statement contained in a footnote to § 153 

 A of the seventh and latest English edition of the ( J udutitdthx Analysis, 

 and also to be found in the earlier editions of this work (4th, oth, Hth). 

 Having given in the text the method of separating fr<mi magnesium 

 and alkali salts the small quantity of barium left in solution by 

 ammonium carbonate, namely, by adding three or tour drops of dilute 

 sulphuric acid, Fresenius states in the footnote to it that the gentle 

 ignition there directed t^) be made in order to expel ammonium salts, 

 will also effect the removal of any small quantity of sulphuric acid 

 which may remain after ))recipitating the bai'iuni. It is this state- 

 ment which needs correction. 



Even in § 6<S, ((. and § 74. a, of the same work we find enough 

 to cause us to doubt the accuracy of the later statement, for it is there 

 mentioned that magnesium sulphat^e is not decomposed by igniting it 

 with ammonium ohloride. arid, on the authority of Rose, that potas- 

 sium and sodium sulphates, which are decomposable by this treatment, 

 need for it to be effective its rejxiated application at a red|heat inducing 

 effervescence. Obviouslv, such ignition as this is not that gentle 



