213 



the case of the wash-bottles served also for the introduction of bromine 

 as needed. 



In the flask were placed 25 cc. concentrated sulphuric acid and 

 25 cc. ordinary strong alcohol, so-called 95 per cent; the mixture was 

 heated to 140° and the temperature maintained as nearly con.stant as 

 possible, alcohol being run in continuously from the funnel. The dis- 

 tillation lasted a total of oSVz hours exclusive of interruptions. Air 

 was then aspirated through the whole apparatus to sweep out remaining 

 vapors; a small quantity of black residue was left in the flask. 



Examination of the Distillate. 



The distillate measured 4,100 cc. from 4,700 cc. of alcohol used; 

 it was acid to litmus and its gravity was 0.830 at 18°. 



The apparent loss is due largely to the formation of ethylene, evi- 

 dence of which was shown by a layer of ethylene bromide in the wash 

 bottles. 



One liter of the distillate was saponified with an excess of sodium 

 hydroxide, to convert all esters into the corresponding sodium salts, 

 and distilled down to 50 cc, the distillate being again distilled down to 

 about 5 cc. and the residues were mixed. It was alkaline. 



Sulphur as Sulphur Dioxide and Sulphites. 



The alkaline residue was diluted and an aliquot part was acidified 

 with hydrochloric acid and distilled into bromine water to convert the 

 sulphur dioxide evolved into sulphuric acid, which was determined as 

 barium sulphate; the sulphur found amounted to 1.03 per cent of that 

 employed as sulphuric acid. The contents of the two wash-bottles con- 

 taining bromine water were freed from bromine and precipitated with 

 barium chloride and 0.96 per cent of the original sulphur found. Dur- 

 ing the preparation of ether, therefore, 1.99 per cent, of the sulphur 

 of the acid used was lost from the generating flask in the form of sul- 

 phur dioxide and sulphites. 



Sulphur as Sulphuric Acid and Sulphates. 



An aliquot part of the alkaline residue from the saponification was 

 analyzed for sulphates by precipitation as barium sulphate. The sul- 

 phur found amounted to 89.42 per cent of the total found. 



