188 Messrs. Thorpe and Young on the Combined Action 



4. Fraction boiling below 100°. — After repeated distillations over sodium 

 this portion was almost completely resolved into three fractions, boiling 

 constantly at (1) 32-38°, (2) 65-70°, and (3) 94-97°. The quantity 

 of liquid boiling below 30° did not amount to 5 cub. centims. Although 

 the distillation was conducted in winter, and freezing-mixtures of 

 snow and salt were employed for the condensation, the greater portion 

 of the product boiling at 32-38° came over at about 35° ; this boiling- 

 point would indicate that the liquid is probably either quintane or amy- 

 lene, or a mixture of these hydrocarbons. In order to decide the point, 

 the distillate was treated with bromine. The liquid was violently 

 attacked, and each drop of bromine combined with the hydrocarbon with 

 a hissing noise ; so energetic was the reaction, that, in order to moderate 

 it, it was necessary to immerse the hydrocarbon in a freezing-mixture. 

 When proper care was taken to cool the liquid, scarcely a trace of hydro- 

 bromic acid was evolved. In order to prevent the possible formation of 

 higher brominated products, the addition of the bromine was from time 

 to time interrupted, and the liquid submitted to distillation ; it invariably 

 commenced to boil at about 32°, and the distillation was maintained until 

 the thermometer stood at 50°. The distillate was again treated with 

 bromine in the cold, and again distilled, the process being repeated 

 until it was without visible action upon the hydrocarbon, — that is, 

 until the liquid was permanently reddened. It was then washed 

 with dilute potash solution, and rectified over sodium; it boiled con- 

 stantly at 35-37° ; the liquid was evidently quintane, and in all probability 

 normal quintane, the boiling-point of which is given by Schorlemmer at 

 37-39°, and by "Warren at 37°. The amount was far too small to 

 attempt the preparation of any derivatives from it. The brominated por- 

 tion boiling above 50° was then distilled ; the thermometer rose rapidly 

 to 180°, and the whole of the liquid came over below 200°. After re- 

 newed distillation the liquid was found to boil constantly, but with 

 slight decomposition, at 184-188° ; this compound is amylene dibromide, 

 the boiling-point of which, according to Wurtz, is in the neighbourhood 

 of 180°. 



0-6515 grin, bromide gave 1*0125 grm. Ag Brand 0*0235 grin, reduced 

 silver. 



Calculated* Found. 

 Br. , f 69-5 68-8 



5. The fraction boiling between 65° and 70°, which was at least fifty 

 times greater than that boiling at 32-38°, was then treated with bromine ; 

 the bromine was absorbed with the same avidity as in the preceding case ; 

 and it was equally necessary to co&l the hydrocarbon in order to moderate 

 the reaction. As soon as the liquid appeared permanently reddened, it 

 was distilled. The portion boiling below 80° was no longer instantly 

 attacked by bromine \ it was accordingly free from the accompanying 



