304 Chenueal exumination of the Hop. 
filtered and evaporated, it yiclded ten grains of a pale yel- 
low extract, intensely bitter, and possessing ia a high de- 
gree the peculiar aromatic taste of the hop. 
Exp. 2.—Two ounces of the best merchantable hops 
were distilled in a retort, with six ounces of water, till half 
of the fluid had passed over into a receiver of water.’ The 
water in the receiver was slightly impregnated with the 
odour of the hop, but there was no appearances of volatile 
oil. 
Exp. 3.—Two drachms of lupulin were boiled in a re- 
tort with three ounces of alcohol. ' The alcohol came over 
strongly impregnated with the aroma of the lupulin; but 
there was no visible indication of an essential oil. The re- 
maining alcohol had assumed a brillant yellow colour, and 
a pleasant but intensely bitter taste 5 when filtered and 
evaporated, it yielded one drachm of extract of the consis- 
tance of soft wax.* 
Exp. 4.—A saturated decoction of the lupulin was pre- 
pared with pure water. It was opaque and of a pale yel- 
low colour. By adding to a portion of it a solution of the 
sulphate of iron, the colour was changed to a deep purple, 
approaching to dele a solution of anata gelatine, threw 
down a copious ash- coloured precipitate, which left the su- 
pernatant liquor transparent and clear. ‘This liquor was 
now decanted; by adding to it a solution of iron, it was 
changed to a pale blue ; the acetate and subacetate of lead, 
caused a copious curdy yellow precipitate; the nitrate of 
silver, a greenish flocculent precipitate; muriate of tin, when 
first added, produced no change, but after standing a short 
time, a brown precipitate ; a Solution of sulphate of alu- 
mine caused no immediate change, but by boilmg with the 
decoction, it separated a dense precipitate. Silicated pot- - 
ash, alcohol, and vegetable blue, induced no change. 
Exp. 5.—Two drachms of lupulin in four ounces of wa- 
ter, were digested six hours in a sand bath. ‘The infusion | 
yielded by evaporation six grains of aromatic and_ bitter 
* These experiments, with some variation, were fre quently repeated, 
with the view to detect, if nracticabie, the volatile oil which is so frequent- 
ly mentioned by authors as essential fo the flavour of beer. The result was 
uniformly t he same. The pee lia aroma of the hop was always obvions 
to the smell and taste, but Fives never able to separate it im the form af aa 
essential oil. 
