334 Scientific Proceedings, Royal Dublin Society. 



The oxides of the alkaline earths and the alkalies give the 

 reaction ; but, of course, their own alkaline reaction is sufficiently 

 marked to render an experiment with the sodium acid-carbonate 

 superfluous. 



Magnesium carbonate 3 Mg00 3 , Mg(HO) 2 4 H 2 0, and Bismuth 

 carbonate 2 (Bi 2 2 C0 3 ) H 2 0, being basic carbonates, give a slight 

 pink tinge, but present no diagnostic difficulty owing to the 

 evolution of C0 2 on acidulation. 



The ferric oxide and alumina, as might naturally be expected, 

 give no reactions, as the carbonates are not known to exist. We 

 thus see that this reaction is of very general application ; but it is 

 right that we should bear in mind that some of the ignited oxides 

 lose more or less the power of decomposing the acid-carbonate. 

 The same remark applies to most of the mineral oxides as found 

 in nature. 



