27 



It is perfectly possible, then, to distinguish a complex oil by the 

 irregularities in the shape of the curve, and when several oils of widely 

 varying properties are present in any mixture this method of analysis 

 will show their presence. 



CONCLUSIONS. 



This article has outlined a method of analysis by fractional distilla- 

 tion with steam, and has shown the results of the application of this 

 met hod to four turpentines of different kinds. 



In discussing the results three physical properties have been given 

 emphasis specific gravity, index of refraction, and temperature of 



J- 



6 /.47D 2 4 

 JM0X Of 



S /.480 2 463 /4X 2 463 /SO 



A CT/OM - /5 'C. 



PIG. 16. Percentage weight-index of refraction curve for a crude destructive-distillation turpentine. 



distillation with steam. These three properties were chosen because 

 they lend themselves to rapid determination and clear interpretation. 

 The odor and color were also found to be of value in the final conclu- 

 sions. The basis for the judgment of an oil has been the combined 

 interpretations from the various physical properties as indicated in the 

 shape of the curves, and no one physical property has been assumed to 

 be all-conclusive. The interpretations from the various physical 

 properties have been seen, however, to harmonize very well. 



Certain advantages of this method seem worthy of mention. 



(1) By introducing the principle of dephlegmation the separation 

 of the constituents is made much more complete. 



[Cir. 152] 



