302 Chemical examination of the Hop. 
course run into the bottle, until the gas within is so much 
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. Atce, 
a third tube for supplying hydrogen, to be ignited by a 
spark from the knob of the bent wire below it. 
Arr. XIV.—An Experimental Inquiry into the chemical 
properties and economical and medicinal virtues of the 
upulus, or Common Hop, by Ansuu W. Ives, 
— M.D. of New-York, 
Tue hop is a hardy perennial plant, which grows spon- 
arts of 
+ 
* That the Humulus is a native of America, bas been confirmed by the 
licheaux, Nuttall, Eaton, Torrey, and others. 
+ A very aceurate drawing and minnte dissection of the male and female 
hee may be found in “ Lamarch’s Encyclopedia,” part 22d, plate 
t 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. __ 
