GPND 



22 WOOD TUKPENTINES. 



very clearly that, so far as the completeness of the separations and 

 the corresponding ease and accuracy of the interpretation of the 

 results are concerned, direct distillation through a dephlegmator is 

 the best distillation method for the analysis of turpentine. 



CHANGES IN COMPOSITION DURING DISTILLATION. 



A possible objection to direct distillation with dephlegmators x is 



that the higher 

 temperatures r e - 

 quired are likely 

 to decompose some 

 of the oil during 

 the distillation so 

 that the fractions 

 will not represent 

 the true composi- 

 tion of the original 

 material. In those 

 distillations in 

 which the same 

 turpentine was dis- 

 tilled direct and 

 by s t e-a m there 

 were no evidences 

 o f decomposition 

 in any case except 

 that the residues 

 left in the distil- 

 ling flask were usu- 

 ally darker in color 



FIG. 8. Comparison of fractionation obtained by direct dis- when direct distil- 

 tillation with a Le Bel-Henninger dephlegmator and steam . V, 1 K 



distillation with a Geer dephlegmator. 



used ; the differ- 

 ences in the curves obtained by the two methods were of such a nature 

 as would indicate only a different fractionation. 



155 160 165 170 I 5 I8O 



1 



\ 



7 



95 96* 97 98 99 IOO BOILING POINT- STEAM DISTILLATION 

 SPECIFIC GEAVITY AT I5C6 .87 .88 ff) .90 91 32 93 34 

 INOex OF REFE ACTION AT 15 C. U74U76 W78 U80 U82 L484 W.B6 



CHANGES IN PHYSICAL PROPERTIES AT CONSTANT TEMPERATURES. 

 CRUDE WOOD TURPENTINE. 



In order to obtain some idea of the comparative effects of different 

 methods of distillation on the physical properties of turpentines, two 

 samples of the same turpentine (turpentine No. 4) were boiled under 

 conditions similar to those of steam and direct distillation that is, 



1 This objection is mentioned in Forest Service Circular 152, " The Analysis of Turpen- 

 tine by Fractional Distillation with Steam," by William C. Geer. 



