| 46 Improved Eudiometrical Apparatus, by Dr. Hare. 
The method of operating with the steel eudiometer and 
water gage, over mercury, has been facilitated, by allowing 
the upper end of the inner gage tube to communicate through 
* a flexible leaden pipe, with a bell glass containing the gase- 
ous mixture to be analyzed. Of this improved arrangement, 
the preceding figure is a representation. G, the inner gage 
tube; P, the pipe; H, the bell glass, within the jar, J. It 
must be imagined, that the bell glass, after being supplied 
with the gas by one of the volumeters, articles 18, 19,* has 
been placed in the jar, J, containing water, under the sur- 
face of which the bell is pressed down by the wire, W. D is 
a steel spring, which has a disk of oiled leather let into it, so 
as to correspond with the surface of the apex of the receiver, 
A, which is ground as true as possible. Hence, a slight 
pressure from the screw, B, renders the joint, made between 
athe apex of the receiver and the spring, air tight; while, at 
the same time, the bore of the cock, C, communicates with 
the cavity o: receiver, by means of a perforation through 
the leather and spring. On the other hand, the relaxation of 
the screw, permitting the spring to rise, opens a communica- 
tion between the cavity of the receiver and the external air. 
In order to fill the receiver with gas, through the gage 
tube, G, and the pipe, P, by which it communicates with the 
ous mi: e bell gl iometer m 
y air, as already 
stated, article 15 ;* and the rod, E, wholly within its tube, T. 
be proportionably supplied with the gaseous mixture. In or- 
der to get rid of the atmospheric air, in the gage tube- and 
pipe, it is necessary to fill and empty the receiver, from the 
ll glass, at least twice. 23 
The receiver being filled, as already described, and the 
cock, F, closed, on pushing the rod, E, home, the gaseous 
mixture, driving the air before it, through the interstice be- 
tween the gage tubes, will in part effect its escape, in part 
supply, in the tubes, the place of the air which it has expell- 
ed.+ The cock, F, being opened, this process may be re- 
a 
~ 
*or the 2 . ~s : i s e-. 
‘he engravings and descriptions of apparatus used in the chemica! 
sis. ap the University of Pennsylvania. re es 
merican Journal of Science for Oct. 1825, p. 75. 
