NAT. OftDER. SCABRID^. 
169 
Sensible mid Chemical Properties. — -The dried strobiles have 
a peculiar fragrant odor, and a very bitter, somewhat aromatic, and 
a slightly astringent taste. New hops are of a pale, greenish- 
yellow hue, and appear like thin, ' transparent leaves ; by long 
keeping their color changes to a yellowish-brown. The watery 
infusion has a pale straw color, is rendered muddy by the mineral 
acids ; alkalies deepen its color ; it strikes an olive with sulphate 
of iron ; is precipitated by solutions of nitrate of silver, tartarized 
antimony, superacetate of lead, and alcohol : and when rubbed 
with magnesia, or lime, a rod dipped in muriatic acid discovers the 
presence of ammonia. By distillation in water, an essential oil is 
obtained. The virtues of hops are extracted by alcohol, ether, and 
boiling water ; by long boiling the aromatic properties are dissipated. 
From the experiments of Dr. Ives of New York, it appears, that 
the active properties of hops reside in a powder, which may be rea- 
dily separated from the strobiles, by merely sifting in a fine sieve. 
This substance forms about one-sixth part of their weight, and to it 
Dr. Ives has given the name lupulin. According to Dr. Ives' analy- 
sis, 120 grains of lupulin contain about — of tannin 5 grains, extrac- 
tive matter 10, bitter principle 11, wax 12, resin 36, lignum 46. — 
The extractive matter is soluble in water only ; the bitter principle 
is soluble in water and alcohol ; the wax is soluble only in alkahes 
and boihng ether ; the resin is soluble in ether and alcohol ; the 
aromatic and bitter properties of the lupulin are more readily and 
completely imbibed by alcohol than water, and much sooner by both 
when hot than when cold ; about five-eighths of lupulin are soluble 
in water, alcohol and ether, three-eighths being vegetable fibrous 
matter. M. Payer and A. Chevaher have confirmed Dr. Ives' opin- 
ion, that the properties of the hop reside in the lupuhn, or the yel- 
low grains which are scattered over the membranous scales of the 
strobiles. They also discovered a volatile oil in lupuhn, which is 
similar in odor to the hop, but much more penetrating. The fol- 
lowing process has been practised by M, Planche, for purifying 
lupulin. 
