32 WOOD TURPENTINE. 



wood turpentine from the pine oils. The distillate, consisting of 

 water and turpentine, flowed from the condenser at a quite uniform 

 rate of 1 gallon in from one minute to one and one-fourth minutes. 

 As it was not feasible to measure the distillate, the refined wood 

 turpentine, nor the pine oil recovered from the charge, these can 

 only be calculated from the rate of distillation for the three experi- 

 mental runs. These results are only approximate, but show roughly 

 the quantity of heavy oils passing into the wood-turpentine storage 

 tank. 



The results obtained with the ordinary pot still having a goose- 

 neck (Tables 9 and 10) agree quite well with those from the column 

 still in indicating that the percentage of turpentine in the distillate 

 must not fall below 54 if 90 per cent of the refined product is to 

 distill below 170 C. Also that the portion of the distillate which 

 contains between 54 and 30 per cent of oils is a mixture containing 

 much pine or heavy oils, which should be again distilled to separate 

 the turpentine from it; and, finally, that when the distillate contains 

 less than 30 per cent of oils, these oils are not turpentine but pine oils. 



In these experiments, the distillation of the so-called turpentine 

 may be roughly divided into three periods; the first covering some- 

 what less than a third of the time, during which the light oils (90 per 

 cent of which distill below 170 C.) are passing over; the second 

 period covering from one-third to two-fifths of the total time, when 

 a mixture containing larger and increasing quantities of heavy oils is 

 distilling; and the last period, approximating one-fourth of the time, 

 when heavy oils which should properly go to the pine-oil tanks are 

 distilling. 



Calculations based on the refining data indicate that the crude 

 oils contained approximately 70 per cent of wood turpentine dis- 

 tilling below 170 C. Calculations from the factory records and the 

 analysis of the refined wood turpentine showed 60 per cent of wood 

 turpentine in the crude oils. The apparent discrepancy is doubtless 

 due to the fact that no accurate measurements of volumes are avail- 

 able for calculation. 



A comparison of the data in Tables 6 and 10 shows that the samples 

 taken from the column still and from the pot still, when the percent- 

 age of turpentine in the distillate was the same, are much alike in 

 composition. It must be remembered in comparing the data that 

 the percentage of turpentine in the distillate can not be determined 

 with great accuracy. The figures given may be in error 2 per cent. 

 Further, the distillation of the samples from the column still were 

 made with emergent thermometers and were not corrected for 

 pressure. 



On the whole, the data from the two forms of stills are very con- 

 cordant. They agree in indicating that as long as the distillate from 



