DISTILLATION OF STUMPWOOD. 57 
proportion of the turpentine fraction is retained in the residual 
pine oil. 
Because of these defects in refining processes, efforts were di- 
rected in the beginning of this work to devise a laboratory method 
for recovering a maximum of high-grade spirits from the crude oil 
that would be applicable to the operation of a commercial plant, on 
the basis of which yields of commercial turpentine from different 
woods could be compared. It soon became apparent that sufficient 
importance is not attached to the amount of alkali required and to 
the manner of its application. Instructions merely to distil with 
alkali or to treat with alkali until action ceases are entirely inade- 
quate, because the amount of alkali used materially affects the pro- 
portion of the hght fraction, the sharpness of the fractionation, and 
the quality of the turpentine as indicated by its odor, color, and boil- 
ing point limits. The intimacy and period of contact of the alkali 
has equal or greater influence. 
The alkali appears to serve a double purpose, aside from that of 
neutralizing the free acid present in the crude oil. First, it brings 
an apparent polymerization of the aldehydes whereby these are con- 
verted into resinous, nonvolatile compounds, in which form their 
elimination from the turpentine is effected on distillation. Second, 
‘the action of the alkah, if used in sufficient quantity, results in the 
formation of a soap with the tar and resin acids. This, in a man- 
ner not understood, although it may be through formation there- 
with of a so-called water-soluble oil, restrains the escape of the 
pine-oil constituents, while the turpentine distils over, thus effect- 
ing a materially sharper separation of the two. The alkali solution 
being mmmiscible with the turpentine and the polymerization process 
partaking in its nature of a catalytic or surface reaction, the effec- 
tiveness of the alkali depends on extremely intimate contact with 
the turpentine for a sufficient length of time to permit the carrying 
of the reaction to completion before beginning the distillation. It 
is in this respect that refining methods as ordinarily carried out are 
wrong in principle, for the reason that, with the alkali added in the 
still, distillation begins before completion of the reactions that “fix” 
the aldehyde bodies. These in part pass over with the turpentine 
and are removed from the sphere of action of the caustic solution 
before the reactions that render them nonvolatile have been com- 
pleted. Agitation of the turpentine in a separate vessel and remov- 
ing and distilling the oil thus separated from the alkali are also: - 
wrong in principle, because advantage is not taken of the deterring 
action of the soap solution on the distillation of pine oils. 
To combine the action of the two principles here set forth the 
erude-oil is agitated with caustic soda solution at boiling tempera- 
ture in a return-flow condensing apparatus before distilling. Me- 
