302 Chemical examination of the Hop. 
course run into the bottle, until the gas within is so muck | 
condensed, as to resist the pressure of a column of it suffi- 
ciently high to reach the orifice of the inserted vessel. 
When this takes place, no more will descend, until by 
opening the cock, a portion of gas escapes: but as long as 
it is escaping, a proportionable quantity of water will come 
down, so as to keep the gas under an equable pressure, and 
of course an even flow towards the blowpipe. 
Fig. 10, represents Lavoisier’s apparatus for the recom- 
position of water, which Dr. Clark so uncandidly insinuates 
as suggesting the contrivance of the hydro oxygen blow- 
pipe. Ata, is a tube, by which, to exhaust the vessel A of 
air. Atb, is another tube for supplying oxygen. At ce, 
a third tube for supplying hydrogen, to be ignited by a 
spark from the knob of the bent wire below it. 
Art. XIV.—An Experimental Inquiry into the chemical 
properties and economical and medicinal virtues of the 
Humulus Lupulus, or Common Hop, by Anse W. Ives, 
M. D. of New-York. 
THe hop is a hardy perennial plant, which grows spon- 
taneously in the northern parts of Europe and America.* 
It belongs to the class Diecia, and order Pentandria, of 
Linnevs. The plant which bears the male flowers is not 
cultivated, and is called the wild hop.t The common do- 
mestic hop, which is the female plant, is now to be the sub- 
ject of investigation. _ Its general character is too well and 
too universally known to need description. The hopf has 
been regarded from time immemorial as an indispensable 
ingredient in malt liquors. It was introduced and cultiva- 
ted for that purpose in England about the year 1549, and 
has smce been used so extensively in that country and in 
many others, as to have become an important article of com- 
* ‘Phat the Humulus is a native of America, has. been confirmed by the 
- observation of Micheaux, Nuttall, Eaton, Torrey, and others. 
_ + Avery accurate drawing and minute dissection of the male and female 
hop-plant, may be found in “ Lamarch’s Encyclopedia,” part 22d, plate 
$15. 
{ Writers have generally used the term hop-plant to distinguish the whole 
vegetable, and the hop to designate that part of it used in brewing. 
