ELISHA MITCHELL SCIENTIFIC SOCIETY 101 



third^ 101 — 110° contained both chlorine and .sulphuric acid, the 

 latter coming from the slight excess used in precipitating the 

 barium. As the first only gav^e promise of interesting results, 

 it was saturated with Agfi, filtered, evaporated over sulphuric 

 acid and the thin crystalline film left was analyzed. xVs the 

 amount of silver found was within two per cent, of that required 

 for silver acetate it was concluded that the principal acid present 

 in the aqueous solution was acetic acid. The presence of the 

 chlorine, sulphuric acid and oily impurities prevented an exami- 

 nation of the other fractions for butyric or other acids and the 

 amount was too small to attempt to purify them. 



The Oil Insoluble in Water. — The oily portion after the 

 washing and thorough drying over calcium chloride was sub- 

 jected to fractional distillation under diminished pressure."^' In 

 this fractionation that part boiling below 120° was looked upon 

 as mainly unchanged heptylen. The fraction from 120° — 160° 

 was set aside. It contained chlorine and in after attempts at 

 reduction persistently retained it. The remaining portion was 

 fractionated three times, yielding fractions as follows : A. 160° — 

 173°; B. 173°— 177°; C. 177°— 185°; D. 185°— 200°; and 

 E. over 200°. This last fraction was quite small, the thermom- 

 eter rising rapidly until only a few drops remained. None of 

 these fractions were more than a few c. c. in amount. All were 

 at first clear, colorless liquids, but the last two rapidly darkened 

 even thouo^h in sealed tubes and carefully secluded from the liiiht. 



Fraction B was the largest in amount (6 — 7 c. c), and as the 

 thermometer rose slowly from 173° — 177° this was supposed to 

 be the purest substance or the nearest approach to a single chemi- 

 cal individual. As stated before, it was the result of three care- 

 fid fractionations. It was subjected to the first and most com- 



*It was found in this case and others where a not very stable product had to be 

 distilled that a reduction of pressure by 100 mm. was sufficient to admit of the 

 distillation eoing on without decomposition. Apparently all that was necessary 

 was a rapid removal and condensation of the vapors formed so as not to subject 

 them for any great length of time to the action of the heat or of products of 

 decomposition already formed. The reduction of pressure reached could ouly 

 lower the boiling point a few degrees. 



