CHEMICAL AND PHYSICAL PAPERS. 65 



(47.6 per cent.) The residue, insoluble in alcohol, gave, on dissolv- 

 ing in water — acidifying with hydrogen chloride, etc. — 2.05 grams of 

 barium sulphate, which corresponds to 1.25 grams (5 per cent.) sodium 

 sulphate. 



2. Upon Sodium Isoamylate. Ethyl Isoamyl Sulphate, C2H5O- 

 S02-OC,5Hii. Twenty-two grams ( 1| mols.) sodium isoamylate, dried 

 at 220° in a stream of hydrogen under reduced pressure, were sus- 

 pended in 100 cc. absolute ether, and cooled in a freezing mixture of 

 ice and salt, and 19.5 grams chlorsulphonic ethyl ester added ; drop by 

 drop. The temperature was allowed to rise slowly to about 15° and it 

 was observed that the sodium isoamylate gradually dissolved, and that 

 salt did not separate even after half an hour's standing at room tem- 

 perature. On heating the mixture, however, under a reversed con- 

 denser, much salt was deposited. The ethereal filtrate was first 

 distilled at about 100 to 150 mm. pressure in order to remove the ex- 

 cess of ether, the amyl alcohol, and amyl ethyl ether. The two last 

 substances were formed in considerable amounts but were not quan- 

 titatively separated. The residual oil was distilled at about 18 mm. 

 pressure ; there was much charring with evolution of sulphur dioxide, 

 but the distillate, after washing with dilute sodic hydrate and drying 

 with calcium chloride, yielded 5 grams (37 per cent.) of jjure ethyl 

 isoamyl sulphate (described below). The salt residue insoluble in 

 ether was worked up in the same manner as the salts formed from 

 sodium ethylate. already described. The absolute alcoholic extract 

 weighed 7.4 grams and proved to be sodium isoamyl sulphate, although 

 possibly sodium ethyl sulphate may have been present in small quan- 

 tity. Considered as sodium isoamyl sulphate, the amount found was 

 29 per cent, of the theory. The remaining salt residue yielded 6.88 

 grams BaSOi, corresponding to 4.19 grams (21.8 percent.) of sodium 

 sulphate. 



In a second experiment, 34 grams sodium isoamylate, 150 cc. ether 

 and 30 grams chlorsulphonic ethyl ester were used. The ethereal so- 

 lution was not heated under the reversed condenser, as in the jDre- 

 ceding experiment, but on adding about 25 cc. of cold water a thick 

 gelatinous mass of salts was precipitated, which dissolved on adding 

 (125 cc.) more water. The ethereal solution was washed frequently 

 with water, dried with calcium chloride, and subjected to fractional 

 distillation under reduced pressure. The oil that remained after the 

 removal of the amyl alcohol and amyl ethyl ether was, however, not 

 directly distilled, but first again taken- up in ether, washed with dilute 

 caustic alkali, dried with calcium chloride, and then distilled at re- 

 duced pressure. Thus 20 grams (49 per cent.) of pure ethyl Lsoamyl 

 sulphate were obtained. 



