DISTILLATION OF STUMPWOOD. 87 
The yield of calcium acetate is approximately but one-fourth of 
that generally obtained in distilling the best hardwoods. Probably 
on a commercial scale the yields would be somewhat less than those 
shown by the analyses. The yield of wood alcohol also is but one- 
fourth of that generally obtained in hardwood distillation. 
PRODUCTS OBTAINED IN REFINING CRUDE TURPENTINE. 
REFINED TURPENTINE. 
In order to separate the valuable turpentine constituents of the 
crude turpentines from the pyroligneous and resinous heat-decompo- 
sition products of the wood, the crude turpentines are first treated with 
caustic soda, which combines with acids and resinifies the aldehydes 
and phenols, forming nonvolatile compounds. By a subsequent steam 
distillation the turpentine and pine oil are recovered. Just as in the 
case of the original retort distillation of the wood, the oily products 
of the steam distillation are separated into several fractions. The 
first product is called “ first grade” or “ first-quality refined turpen- 
tine.” The receivers are changed at a certain point (page 58), and 
the distillate which then comes over is called “refined second- 
quality turpentine.” This has distilling temperature limits somewhat 
higher than those accepted for true commercial wood turpentine. 
Finally, the receivers are changed again, the last of the distillate be- 
ing called “ pine-oil fraction.” 
On refining crude first turpentine a yield of approximately 80 per 
cent of refined first-grade-turpentine is obtained, most of which dis- 
tils between 170° and 175° C. From crude second turpentine the 
yield of refined first-quality turpentine lies in the neighborhood of 
43 per cent. The other distillates from the crude turpentines are as 
follows: From crude first turpentine, 54 per cent refined second- 
quality turpentine fraction and 74 per cent pine-oil fraction; from 
erude second turpentine, 13 per cent refined second turpentine and 
12 per cent pine-oil fraction. 
