. 
DISTILLATION OF STUMPWOOD. 31 
CRUDE PRODUCTS OF RETORT DISTILLATION. 
CRUDE WOOD TURPENTINE. 
The crude wood turpentine is distilled from the wood during the 
first stage of the destructive distillation. During this first stage of 
distillation the turpentine passes over for the most part unchanged, 
as it probably exists in the wood tissue. The crude first turpentine, 
therefore, is nearly free from pyroligneous bodies. It is often hght 
in color, and usually possesses an agreeable odor. It has a specific 
eravity of about 0.875 at 20° C., a refractive index of about 1.4768 
at the same temperature, and an initial boiling point of about 164° C. 
The crude second turpentine necessarily contains more of the pyro- 
ligneous or heat-decomposition products and of the heavier pine oils, 
since the retort operator cuts the distillate at the first signs of de- 
composition of the wood, indicated by the appearance of noncon- 
densable gases, and collects the remainder of the turpentine as “ sec- 
onds.” The heat-decomposition products of the rosin and wood 
_ constituents consist of acids, alcohols, ketones, phenols, aldehydes, 
etc., the nature and quantity of which depend on the temperature 
ones rate at which the tur pentine stage of the distillation is conducted. 
This crude second turpentine is darker than the crude first, and its 
color is sharper and more suggestive of wood decomposition. It has 
| _ aspecific gravity of about 0.910 at 20° C., a refractive index of about 
1.4850 at the same temperature, and an initial boiling point of about 
130° C. (due to the presence of decomposition products). 
The difference between these two crude turpentines is well set forth 
in Table 15. 
TABLE 15.—Products of dry distillation of crude turpentine at 760 mim. pressure. 
fe First Second 
Temperature of distillation (°C.). turpen- | turpen- 
tine. tine. 
Per cent.| Per cent. 
9.3 oe) 
TBYEL ONC NAD fe SS a ed ae ee ea gd BAYS BOk ANE 9 Bok LM (G0 Ee Aad eh AGE Hae os Be ANE tA 
[SBI WEG UDB IG! NGDSS SSeS eS a a ee ee ae Ge a I i A CP Pa 52.8 9. 06 
isang Ae. camGl Ot see ae ee RA see pee SS aie ies: oe eee eee Rea ee ee 16.0 18. 05 
wae UGG: ere L WEISS 5 Cis se AR ie eS ear te RecA PRR a (ee 18. 02 
AEST Copper we pS NAR ae eh cera Lo) ONE Cue NS 3 ae we 21.9 47.37 
The details of refining the crude turpentine are discussed on 
page 56. 
LIGHT OIL. 
The crude light oil is brownish black, has a sharp, penetrating, 
empyreumatic odor, an average specific gravity of about 0.995, a 
refractive index of 1.514, each at 20° C., and an acid value of aonte : 
29. Its average Fics ab, 25oh Osis 2.58° Engler. The yield is 
about 44 gallons a cord of rich wood. Distilled in the ordinary 
manner at atmospheric pressure, using a fractionating column, it 
has an uncertain initial boiling point, around 70° C., due to the pres- 
