304 Chemical examination of the Hop. 
filtered and evaporated, it yielded 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. 
water in the receiver was slightly impregnated with the 
odour of the hop, but there was no appearances of volatile 
oil. 
xp. 3.—Two drachms of lupulin were boiled m 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 brilliant yellow colour, and 
a pleasant but intensely bitter taste; 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 black ; a solution of animal gelatine, threw 
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 Jead, 
caused a copious curdy yellow precipitate; the nitrate of 
silver, a greenish flocculent precipitate; muriate of tin, w 
first added, produced no change, but after standing a short 
time, a brown precipitate; a solution of sulpbate of alu- 
mine caused no immediate change, but by boiling with the 
decoction, it separated a dense precipitate. Silicated pot- 
ash, alcohol, and vegetable blue, induced no change. 
4p. 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 frequently repeated, 
with the view to detect, if practicable, the volatile oil which is so frequent- 
ly mentioned by anthors as essential to the flavour of beer. e result was 
ormly the same. The peculiar aroma of the hop was always obvious 
os seeeii and taste, but J was never able to separate it in the form of 2° 
