13 



determined on two pure fractions of wood turpentine with indices of 

 refraction above and below 1.4750, respectively. 



There is now for each fraction the steam temperature, the weight, 

 color, odor, specific gravicy, and index of refraction. 



RESULTS. 



The results of the analyses of four different turpentines are given 

 in the accompanying tables and curves. In the tables the data , 

 at the top show the properties of the original sample ; the first 

 column gives the serial number of the fraction ; the second, the steam 

 temperature after correction for barometric fluctuations; the third, 

 the weight of the turpentine in each fraction. The fourth column 

 is made by adding the weight of each turpentine fraction to the 

 weight of all the preceding turpentine fractions, which gives the total 

 weight of oil distilled up to each point. Thus in Table 1 up to and 

 including fraction 3, the total weight of turpentine distilled was 267.66 

 grams. After all the fractions had been collected, the total weight 

 distilled was 493.85 grams, and the undistilled residue amounted to 

 the difference between the original weight taken, 500 grams, and the 

 total weight distilled, 493.85 grams, or 6.15 grams. For purposes 

 of reference and calculation it is more convenient to deal with per- 

 centage weight than with total weight, and hence the fifth column 

 is prepared from the fourth by finding the percentages which each 

 total weight is of the original sample. The sixth and seventh columns 

 give the corrected values for the specific gravity and index of 

 tion of each fraction. From these data three curves are 

 showing the variation of steam temperature, specific gravity, and 

 index of refraction, respectively, with the percentage weight of the 

 distillate. 



TURPENTINE No. 19 A GUM TURPENTINE. 



Table 1 and figures 6, 7, and 8 give the data obtained from the 

 analysis of a gum turpentine according to the methods which have 

 been described. 



TABLE 1. Turpentine No. 19 A gum turpentine. 

 [Specific gravity, 0.8693 at 15; index of refraction, 1.4739 at 15; weight of sample, 500 grams.] 



[Oir. 152] 



