25 



The specific gravity curve is shown in figure 12. The specific 

 gravity of the first 92 per cent of the distillate varied within the limits 

 of 0.8662 and 0.8685. This is almost exactly the difference found in 

 figure 1 . The vertical part of the curve is very straight, and change of 

 direction does not take place until nearly all the oil has distilled. This 

 indicates, then, that the product was of high grade, and consisted 

 chiefly of a pure light oil. 



The index of refraction curve, figure 13, is very similar to that for 

 the gum turpentine shown in figure 7. This change over 92 per cent is 

 from 1.4692 to 1.4722, a difference of 0.0032. 



The steam temperature curve, figure 14, further shows marked con- 

 stancy over a large portion of the oil, and although not quite so per- 

 pendicular as the curve shown in figure 8, still within 1.5 variation 

 in temperature the same per cent of oil distilled, namely, 92 per cent. 

 The inference, then, is that this turpentine is of a high degree of purity, 

 being practically the equal of the gum turpentine previously described. 



TURPENTINE No. 22 A CRUDE DESTRUCTIVE-DISTILLATION TURPENTINE. 



The possibilities of this method are further shown in the results of 

 an analysis of crude turpentine produced by destructive distillation 

 of pine wood. Table 4 presents the data from this analysis. Figures 

 15, 16, and 17 are the curves made from this table for the specific 

 gravity, the index of refraction, and the steam temperature, respec- 

 tively. 



TABLE 4. Turpentine No. 22 A crude destructive-distillation turpentine. 



[Specific gravity, 0.9231 at 15; index of refraction, too dark for a determination; weight taken, 500 



grams.] 



On reference to figure 15 the oil seems fairly uniform over 50 per cent 

 of its composition, with a variation between 0.8678 and 0.8600, 01 

 0.0078. The specific gravity, however, decreases with the distillation, 

 whereas that of all the other samples has increased. This indicates a 

 very different composition. The irregular form of the index of refrac- 

 tion and steam temperature curves (figs. 16 and 17) shows that the 

 oil was one of very complex composition. 



The odor, both of the sample and the fractions, was strong and dis- 

 agreeable, while the color varied from a yellow to a red. 



[Cir. in:.'] 



