1912] Lipmuii-Sharp: Phenoldisulphonic Acid Method 3" 



3. Lime has been fouud to be much more reliable for the pur- 

 pose named than any of the other substances, the losses incurred 

 through its use being very small. 



4. The reason for the difference between the action of Na2S04 

 and NaoCOg so far as the nitrate losses are concerned is to be 

 found in the fact that Na.S04 induces the loss of nitric acid 

 from the solution while the latter is being evaporated, while 

 NaoCO;, containing only a weak acid radicle has no power to 

 set nitric acid free. Neither NaoSO^ nor Na.COo has the power 

 to set nitric acid free from nitrates when the dry residues of the 

 two are mixed prior to treatment with phenoldisulphonic acid. 



5. Losses of nitrates from solutions as induced by chlorides 

 alone seem to be proportional to the amount of chlorine present. 



6. The work of Gill which showed that chlorine induces losses 

 both on the water bath and in mixing the dry residue with 

 phenoldisulphonic acid is confirmed. 



