34 



WOOD TURPENTINES. 



the water, and the speed measured in the indicator J 3 . The speed of 

 the tails is not directly controlled, but is dependent upon the speeds 

 of the other products, being equal to the speed of the crude, minus 

 the sum of the speeds of the two distillates. 



A constant head for the water supply is maintained by means of 

 the float valve in the reservoir E, so that when the valves 4, 5, and 13 

 are once adjusted the flow of water through the condenser B and 

 therefore through the refluxes of A x and A 2 will be constant. The 

 pressure regulators H! and H 2 are used to maintain a constant pres- 

 sure of steam in the bottom section of 

 the columns A and A 2 , respectively, 

 and therefore the speed of the distil- 

 lates, once properly adjusted, should 

 remain constant. There were in most 

 cases, however, small variations in the 

 speed of the different products during 

 the course of the distillation. 



REFINING OF CRUDE TURPENTINE 

 NO. 1. 



Crude turpentine No. 1 was obtained 

 from a plant using the destructive dis- 

 tillation process ; during the first part 

 of the distillation, however, the retorts 

 are heated slowly, so that while the 

 crude turpentine is being distilled 

 from the wood the temperature is kept 

 as low as is feasible. 



ANALYSIS AND CHEMICAL TREATMENT. 



160 165 170 175 I80 185 I9O 195 

 O 46 .87 6 &> .^0 91 .92 .93 

 O 1466 U70 1472 U14 1476 



. 1476 1418 LA80 



FIG. 2i.-Bomng point, specific The analysis of the crude turpentine 



gravity, and index of refraction is given in figure 21. The odor of the 



untleatS ""** ^f^ N ' '' first four fractions was very disagree- 



able, and the color was a dark yellow ; 



these two things, in connection with the high gravity indicated the 

 impossibility of obtaining by distillation alone any refined turpentine 

 of good quality from this part of the crude, although the boiling 

 points were mostly within the range of a good turpentine. Because 

 it was probable that the contaminating material could be removed by 

 treatment with alkali, the original crude turpentine was agitated 

 with a warm caustic soda solution until action ceased. 



The analysis of the treated crude is shown in figure 22. The gravity 

 of the first few fractions was decreased and the index of refraction 

 was increased by the treatment ; the color and odor of all the fractions 



