480 Transactions. — Chemistry and Physics. 



To test this conclusion 36 grms. of crystallized abietic 

 acid was heated in a four-bulb Ladenburg flask at 30 mm. 

 pressure, the temperature in the uppermost bulb being 

 maintained at 210-220° C. Under these circumstances an 

 almost colourless distillate was obtained, and this consisted 

 of an oil which did not solidify on cooling. After five hours' 

 heating the contents of the distilling -flask had become so 

 pitchy that the heating was discontinued. The distillate 

 amounted to 44 per cent, of the acid taken, and consisted 

 of an almost colourless faintly florescent viscous oil, which 

 still contained some abietic acid. The oil was dissolved in 

 toluene, freed from acids by washing with caustic soda, and 

 dried, first over calcium-chloride and afterwards by sodium. 

 Finally, the toluene was removed by distillation, and the 

 residue distilled at 19 mm. pressure. Practically the whole 

 came over between 300-315° C. The product was redistilled 

 over sodium at 82 mm. pressure, when the greater portion 

 distilled at 247-250° C. This was analysed, with the following 

 results : — 



Calculated for CigHas Found. 



C = 88-5 88-3 



H = ll-5 11-7 



The molecular weight was kindly determined by Mr. P. 

 W. Eobertson in phenol solution. 



Found. Calculated for CigH^ 



244 244 



249 AVk 



taking 72 as the depression constant of phenol. (Eykman.) 



It is worthy of note that, though a second receiver was- 

 attached and kept in a freezing mixture during the whole dis- 

 tillation, no volatile products, except a few drops of water 

 slightly discoloured by oil, could be detected. The same 

 hydrocarbon is easily obtained by the slow distillation of 

 common colophony. 



In order to prepare a quantity of the hydrocarbon, a kilo- 

 gram of common rosin was distilled from a cast-iron retort, 

 provided by means of a stuffing-box, with a rod and disc 

 fractionating column. With a little care it was easy to main- 

 tain the still-head at 215-230° C, the pressure being kept at 

 15-35 mm. 100 grms. of the oily distillate was dissolved in 

 300 c.c. of light petroleum, thoroughly agitated with 400 c.c. 

 of 1 per cent, soda-solution, and sufficient alcohol to prevent 

 the formation of a permanent emulsion. The soap-solution 

 was shaken out with a second quantity of petroleum. The 

 hydrocarbon was dried by calcium-chloride, the light petro- 

 leum removed by distillation, and the heavy oil fractionated 

 in vacuo. The following fractions were obtained : — 



