Estimation of Sulphur in Iron. 171 



which were instituted in order to gain an idea of the extent to 

 which the precipitation of BaO SO^ is influenced by nitric acid. 



In the above experiments the sulphate of potash was dissolved 

 in water and the nitric acid added to it. The same volume of a 

 solution of BaCl, containing about twenty times the quantity of 



N2 



