ANALYSIS, REFINING, AND COMPOSITION. 



57 



cent with a gravity of 0.94. Otherwise the sample seemed to be un- 

 changed; it was still colorless and with no appreciable change in 

 odor. 



Refined turpentine No. 3 (original analysis, fig. 33) was analyzed 

 after a period of nine months (fig. 49) ; there were no indications 

 of change in composition. 



Refined turpentine No. 4 (fig. 37) was analyzed after nine months 

 (fig. 50) ; no apparent change in composition had taken place. 



Refined turpentine No. 5 (fig. 43) was analyzed after 3 months 



I60 1 165 170 175 180 165 190 195 

 O .86 T BO 9 30 31 .92 .93 

 O U468 1470 U7Z 1474 U76 1478 U80 



FIG. 49. Boiling point, specific 

 gravity, and indeV of refraction 

 curves for the turpentine obtained 

 from cr-ide No. 3 analyzed after 

 nine months. 



160 165 170 175 160" 185 190 195 

 O 6 7 8 J39 3O .91 .92 .93 

 O 1464 W70 1472 1474 1476 L478 L4W 



FIG. 50. Boiling point, specific 

 gravity, and index of refraction 

 curves for the turpentine obtained 

 from crude No. 4 analyzed after 

 nine months. 



(fig. 51) ; during this short time the amount of heavy residue had 

 increased from 2 per cent with gravity of 0.885 to 4 per cent with 

 gravity of 0.92. Other analyses, made after 6 and 10 months (figs. 

 52 and 53), showed a gradual increase in the amount of heavy residue. 

 At the time of the last analysis a considerable yellow color had de- 

 veloped in this sample, possibly from the natural process of " aging," 

 but more likely by contamination from an incompletely cleaned iron 

 drum in which it was stored during a part of the time. In order to 

 remove this color and also part of the heavy residue, the sample was 



