24 



WOOD TURPENTINES. 



figure 9, being within the limit of possible experimental errors. But 

 the same general tendency of the specific gravity to be slightly in- 

 creased by the direct boiling and slightly decreased by the boiling 

 with water is shown, as in figure 9. The index of refraction is, how- 

 ever, slightly decreased by the boiling with water instead of being 

 increased. 



The effect of the boiling on the physical properties of the turpen- 

 tines is apparently not very great in either case, but for two reasons 

 the results obtained are not conclusive: (1) The temperatures to 



which the turpentines were subjected 

 were only as high as would prevail at 

 the very beginning of distillation, and 

 therefore, in the case of the direct dis- 

 tillation, probably do not come within 

 40 C. of the t temperatures reached at 

 the end of a regular fractional dis- 

 tillation; (2) different components of 

 the turpentine might have the physical 

 properties changed in different direc- 

 tions and thus the changes in the prop- 

 erties of the turpentine as a whole would 

 not show the actual changes in compo- 

 sition which had taken place. There- 

 fore, another method for comparing the 

 changes in composition due to steam 

 distillation and direct distillation was 

 carried out as described below. 



LE6EMD 



160 165 170 175 180 185 190 195 

 O .86 .87 & .89 .90 .91 .92 .93 

 9 1468 U70 L4T2 1.474 1.416 1.478 1.480 



CHANGES IN PHYSICAL PROPERTIES UNDER 

 FRACTION ATION. 



DIRECT DISTILLATION OF CRUDE TURPENTINE. 



Crude turpentine No. 4 was repeat- 

 no. 11. Alteration in physical edl re distilled by direct distillation 



properties oH a crude wood tur- J J , -i i i 



peutine due to direct distillation, through a Le Bel-Hennmger depnleg- 



mator. Each time the heavy residue 



left in the flask and as much of the distillate as showed especially 

 high physical properties were rejected. The first distillation was 

 similar to the direct distillation shown in figure 6, and the frac- 

 tions up to 79.5 per cent formed the material for the next dis- 

 tillation, the residue and the last fraction of the distillate being 

 rejected. The curves showing the course of the third and fourth 

 distillations were practically identical and are both represented by 

 the curves in figure 11. All the heavy oils present in the original 

 turpentine must have been removed by the first two distillations. 



