62 BULLETIN 1003, U. S. DEPARTMENT OF AGRICULTURE. 
proportions as recovered from the crude turpentine, was carefully 
distilled from a Hempel fractionating apparatus, and the boiling 
point, specific gravity, and refractive index curves plotted from these 
data. 3 | 
The boiling point, refractive index, and specific gravity curves 
(figs. 6, 7, 8) point to the presence, to the extent of about 2 per cent, 
SIGS 
DLGREES CEW7/CGRAQE 
SRS 80 SES. 190 
/70 
S05 
Fic. 6.—Boiling point of distillate. 
of a body distilling at a relatively low temperature, having also .a 
much lower refractive index than the major portion of the distillate. — 
This is probably alpha-pinene, which in a pure state has a boiling 
point of 155° C., a specific gravity of 0.858, and refractive index of 
1.4660 at 20° C., whereas the corresponding values of beta-pinene 
are 162° C., 0.868, and 1.4734. Polarimetric readings on the first two 
fractions, up to 6 per cent total distillate, showed laevo-rotations, in- 
