214 



In order to distinguish between sulphuric acid, ethyl sulphuric acid 

 and ethyl sulphate in the ether distillate, the residue on evaporation 

 of an aliquot part was dissolved in water and precipitated with barium 

 chloride; the barium sulphate corresponded to 46.54 per cent of the 

 total sulphur as sulphuric acid. The total acidity of another aliquot 

 part of the residue of the ether distillate was determined by titration 

 with standard alkali; the free sulphuric acid already found as described 

 was subtracted, and the remaining acidity considered as due to ethyl sul- 

 phuric acid, the sulphur in this form amounting to 8.49 per cent of 

 the total sulphur. The total sulphur in the ether distillate (89.42) less 

 the sulphur as sulphuric acid (46.54) and that as ethyl sulphuric acid 

 (8.49) would represent the sulphur as ethyl sulphate, namely, 34.39 

 per cent of the total sulphur. 



As several months elapsed between the preparation of the ether 

 and this examination of the product it is probable that there had been 

 considerable change fi'om ethyl sulphate into ethyl sulphuric acid and 

 sulphuric acid, on account of the hydrolytic action of the water present. 

 At the temperature of 140", however, sulphuric acid (boiling point of 

 the dihydrate is given as 170-199 ) might distill as readily as ethyl 

 sulphate (boiling point 208°); nothing seems to be known as to the 

 possibility of ethyl sulphuric acid distilling as such. 



Sulphur as Sulphonic Acids and Sulphonates. 



The filtrate from the barium sulphate precipitate obtained in the 

 determination of sulphur as sulphuric acid and sulphates was evap- 

 orated to dryness and the residue subjected to a Carius determination 

 for sulphur; 4.62 per cent of the total sulphur was found. 



Examination of the Residue. 



Sulphur as Sulphur Dioxide. 



The residue, weighing 3 grams, stood several months in the closed 

 distilling flask. Air was aspirated through the flask and then through 

 bromine water, and 0.15 per cent of the total sulphur was found in the 

 bromine water. 



