Chemical Contributions. 347 
either be manufactured by grinding two or three glass rings together, 
so that they will fit accurately one within the other, or obtained from 
the glass-house. 
The mode of operation is obvious. We have a quantity of gran- 
ulated zinc in the bottle. The dilute-acid is poured into the funnel, 
passes down, and rises in the tube, till it reaches the orifice (a.) 5 
when it flows over into the interior of the bottle. The gas can es- 
cape through this nozle only by depressing the fluid in the tube quite 
to its bottom, and thus creating a column in the stem of the funnel 
five or six inches in height. 
The advantages of this construction are, 1. Its cheapness and sim- 
plicity ; it is what every chemist can make for himself. 2. There is 
ted into it, so as to occupy its middle part, and leave a vacant space at both ends ; is 
bored, and. has the conducting tube passed through it, in the usual way. There is 
then on each side of the cork, a vacant chamber, into which any kind of lute or ce- 
ment, such as the fat lute, made by beating fine ere and drying oil together, may 
be introduced under such circumstances, as to retain its place with great firmness, 
and at the same time be perfectly impervious to a gas or vapor. 
am thus minute, because I do not recollect to have seen this mode of fitting up 
gas-bottles, noticed in any of the books, and I have found it very convenient. In- 
carbonic 
standing upon 
shelf made to receive it, by the side of the pneumatic cistern, with the substitute for 
Welther’s tube, here described, in one ‘of the nozles, and = glass jacket, holding 
thectrk-enl sondo eting tube, ¢ ther. The solid materials are read- 
ily introduced, and the resulting liquid as “ensily wie noe the acid is added as 
there is occasion for it: not a particle of gas can ae na except along the conduct- 
ihg tube ; and finally, the apparatus is not one which e shall be likely to break. 
oxide by 
glass jackets pe the same orifice; one mos hee delivering the gas at the pneumatic 
cistern, and the other bent twice at right angles, for passing it through the liquid; 
ene of which may ue exchanged for the other i _ moment. The stem of the fun- 
nel of the safety tube, must however be made alittle longer in this case, than where 
the object yest to collect the gas in jars. It mere require the labor of half a day 
to fit up a bottle in this way, but when once finished, it may be used for any length 
of time. 
the books, and more frequently employed. We can in many cases make a close 
Hintin this svay, in as little time as i it: woul) tele: to fit ina cork, and rege the sur- 
ans thati ig 
Se i Pisce them, 
fo il te very in ntity of lute pres 
will make all pekees ik and secure. 
