May as, 1914 
Aroma of Hops 
137 
ticularly true of the California and Oregon oils of the crops of 1907, 
1908, and 1909. The New York, Washington, and imported oils had 
a general tendency to manifest dextro rotation after the fourth fraction, 
the levo rotation of the former fractions being consistently less than the 
same fractions of the California and Oregon oils. The dextro rotation of 
the last three fractions seemed to be higher, in practically all cases, than 
the same fractions of California oils. A most noticeable feature was 
the tendency of the New York oil to follow the same course as the im¬ 
ported oil during each season. The high-boiling portions of the oils, 
of which the esters and sesquiterpenes form a part, tended to show the 
greatest rotation. The curves of rotation, as well as the curves of frac¬ 
tionation, show some differences in the various oils, though perhaps in 
