of Heat and Pressure upon the Paraffins. 



199 



4-425 grins, of bromine would be equivalent to 3*78 grins, of the olefine, 

 leaving 3-625 grms. of the hydride, or the fraction is a mixture of unde- 

 cane and undecylene in equal proportions. 



A determination of the vapour-density of the 193-195° fraction gave 

 the following data : — 



Balloon with air 13-2640 grms. 



Temperature of air 16° 



Balloon with vapour 13-5470 grms. 



Temperature on sealing 261° 



Eesidual air 0-8 cub. centims. 



Capacity of balloon 113 cub. centims. 



Tound 81-1 Calculated 77'5 



11. Fraction boiling between 200° and 300°. — By long-continued distilla- 

 tion over sodium the 2| litres boiling originally between these limits 

 were resolved into the following fractions : — 



(1) 212-215°* 



(2) 230-235° solidifies at — 14°-5f 



(3) 252-255° „ 5°-5 



(4) 273-276° „ +2°-0 



(5) 290-295° 



The portion boiling at 300° (in the neighbourhood of 315°) is solid at 

 ordinary temperatures. 



The following details of the bromination experiments show that the 

 fractions were invariably mixtures of olefines and hydrides : — 

 Fraction 212-215° : 



4-48 grms. required 2-65 grms. of bromine. 

 Fraction 230-235° : 



4-23 grms. required 1'92 grm. of bromine. 

 Traction 252-255° : 



(1) 9*38 grms. required 2-95 grms. of bromine. 



(2) 8*605 grms. required 2-67 grms. of bromine. 



(3) 5*13 grms. required 1*54 grm. of bromine. 

 Fraction 273-276°. 



7'39 grms. hydrocarbon required 2-04 grms. of bromine. 



12. It has already been mentioned that, on the first distillation of the 

 oils obtained by splitting up the 3 j- kilogs. of paraffin, a considerable 

 amount of substance (which could not be distilled within the range 

 of the thermometer) remained in the retort and solidified on cooling. This 

 substance in its crude condition melted at 31°, but on recrystallization 

 from ether the melting-point became higher. The whole of the substance 

 was therefore cut up into small fragments, and spread upon filter-paper 



* These boiling-points are uncorrected. 



t These points of solidification are only approximative, 



