122 
Journal of Agricultural Research 
Vol. II, No. a 
Color, odor, and taste, which appeal solely to the senses, are not 
especially significant. The colors of the various oils, ranging from a 
golden yellow to a dark brown, were due largely to the condition of the 
material and the time of the distillation. The first runnings obtained 
in all of the distillations were nearly colorless, but gradually deepened 
in color as the distillation progressed. The predominant colors seemed 
to be red and brown, the golden-yellow color being obtained only when 
small quantities of hops were distilled on a small laboratory scale. When¬ 
ever large quantities (100 to 200 pounds) were distilled, the resulting oil 
invariably possessed a dark color, the particular tint varying with the 
season. No constant difference was observed in oils from the various 
sources. 
The odor in all cases was naturally characteristic of hops. In some 
instances, however, a slightly musty odor was perceptible. The oils 
from the American hops were all strongly aromatic and in most cases 
agreeable. A slight yet distinctly musty odor was perceived in several 
of the oils, due probably to imperfect drying and subsequent sweating 
of the hops in the bale. The oils from the foreign hops seemed to be 
distinctly different from the American oils, possessing a very pronounced 
flowery odor, combined with a fatty odor, the effect being most agreeable. 
The sense of taste, which is influenced directly by the sense of smell, 
is generally capable of distinguishing definite and characteristic quali¬ 
ties of a substance, such as pungency and bitterness. Acidity and fatti¬ 
ness can also be easily detected. All of the oils in question had a 
decidedly aromatic taste, and there were also a number in which bitter¬ 
ness, fattiness, and acidity were very pronounced. The oils from the 
California hops were all characterized by bitterness and pungency, with 
slight fattiness. The oils from the imported hops were strongly fatty 
with only very slight bitterness and pungency. 
The densities of the California oils bore a close relationship during 
individual seasons, differing somewhat from season to season. This 
would seem to indicate that the approximate composition during any 
one season was about the same in the several oils. The average specific 
gravity of the several California oils for the three seasons was about 
0.8326. It will be seen that the Oregon oils were somewhat higher, the 
average being 0.8385. The oils from the imported hops, with an average 
specific gravity of 0.8433, and the Washington oils, with an average of 
0.8482, followed in order. The oils with the highest general specific 
gravity were those from the New York hops, which averaged 0.8554 at 
24 0 C. This figure would be increased if corrected to the temperature at 
which the specific gravity of the majority of the oils was recorded. It 
is generally acknowledged that the specific gravity is modified by the 
composition of an oil, but it is doubtful whether the differences noted 
above would cause any remarkable change in the quality of the oil. A 
