16 



0.8685, which is .0025, or 0.29 per cent. The 6 per cent between 

 92^ and 99 per cent varied widely in specific gravity, while the last 

 1 per cent remained undistilled. Whether this 92J per cent was 

 composed entirely of one substance, the curve does not decide, for 

 it is possible that two substances of the same specific gravity were 

 present. The term "uniformity of composition" in this paper 

 refers only to physical properties. 



On reference to the index of refraction-percentage weight curve, 

 figure 7, it is seen that this physical property varied in about the 

 same manner as the specific gravity. Over the first 92J per cent 

 distilled, the index of refraction varied only between 1.4718 and 

 1.4757, 0.0039, or 0.27 per cent, and beyond 92 \ per cent the refractive 

 index increased very rapidly. 



The steam temperature curve as shown in figure 8 indicates about 

 the same proportion of uniform composition, since the abrupt change 

 in the direction of the curve takes place at about 92^ per cent. Over 

 this range the steam temperature varies from 94.9 to 95.7 C. 

 About 92J per cent of this turpentine was therefore nearly uniform 

 in composition, and the remainder consisted of a mixture of heavier 

 oils. The original sample was colorless and had a sweet, pine-like 

 odor. Each fraction was colorless and had a pine-like odor, and 

 only the residue was yellow. Practically, Turpentine No. 19 would 

 be considered a high-grade product. 



TURPENTINE No. 14 A CRUDE STEAM TURPENTINE. 



Table 2 gives the data from the analysis of an unrefined, steam 

 distilled, wood turpentine. The specific gravity, index of refraction, 

 and steam temperature curves are shown in figures 9, 10, and 11, 

 respectively. 



TABLE 2. Turpentine No. 14 A crude steam turpentine. 

 [Specific gravity, 0.8834 at 15; index of refraction, 1.4749 at 15; weight taken, 500 grams.] 



[Cir. 152] 



