THE ANALYSIS OF TURPENTINE BY FRACTIONAL DISTILLATION 



WITH STEAM. 



FORMER METHODS OF TURPENTINE ANALYSIS. 



In the course of the studies by the Forest Service concerning the 

 utilization of waste yellow pine wood by distillation processes," it was 

 found that the "wood turpentines" produced by these methods were 

 extremely variable in composition and properties, and that an accu- 

 rate method for comparing and grading them was very necessary for 

 the further progress of the \vork. Most of the methods of turpentine 

 analysis in use were devised simply to detect adulterations in gum 

 turpentine, and there was no satisfactory method applicable to all 

 classes of turpentines which would give an accurate idea of their rela- 

 tive compositions and characteristics. Fractional distillation with 

 subsequent examination of the individual fractions appeared the best 

 for this purpose, but some modifications seemed advisable. This 

 general method is ordinarily carried on as follows : The liquid to be dis- 

 tilled is heated in a flask, the vapors are condensed, and the distillate 

 is collected in several portions or fractions ; the temperatures between 

 which the various fractions distill are recorded, and sometimes one or 

 more physical properties of the fractions are determined. In this 

 manner a general idea of the composition of a turpentine can be 

 obtained, but, as will be shown later, the completeness of the sepa- 

 ration, the ease of interpretation of the results, and the reliability of 

 the data can be increased by extending and modifying the ordinary 

 method. 



MODIFICATIONS INTRODUCED. 



The four following important changes were made : 



(1) A new still head was introduced. 



(2) Steam distillation was used instead of the ordinary distillation 

 with direct heat. 



(3) The graphical method of expressing results was employed. 



(4) More physical properties were determined. 

 These changes will be discussed in order. 



(1) If a mixture of two liquids with different boiling points be dis- 

 tilled, each of the first fractions will contain a larger proportion of the 



"Forest Service Circular 114, "Wood Distillation." 

 [Cir. 152] (5) 



