444 
SIE B. C. BEODIE ON THE ACTION OE ELECTEICITY ON GASES. 
72-000 
o. Q ^gij = 34-957 capacity in cub. centims. at point 1, 
o 
5 5 ~5 
4, 
6 , 
the capacity at point 5, as determined from the pipette, being- 240-89 cub. centims. This 
method of determining the capacity of the aspirator may be termed the method of air 
calibration. 
The capacity of the apparatus at the different points, as determined by the respective 
methods of mercurial calibration and air calibration, are given in the following Table : — 
Capacity 
in 
cub. centims. at point 1 . 
By mercurial calibration. 
. . 34-93 
By air calibration. 
34-96 
55 
55 
55 
55 
55 
2 . 
. . 71-87 
72-00 
55 
55 
55 
55 
55 
55 
o 
O . 
. . 118-88 
119-04 
55 
55 
55 
55 
55 
55 
4 . 
. . 171-92 
172-19 
55 
55 
55 
55 
55 
55 
5 . 
. . 240-51 
240-89 
55 
55 
55 
55 
55 
55 
6 . 
. . 353-45 
353-75 
1 1 9-04 
fi^-;=72-000 
l'ooo4 
172*19 
TVi64= 119 ' 04 
240-S9 
J ■ — 172-19 
1-3989 1 
240-89x1-4685=353-75 
35 33 33 
33 33 33 33 
33 33 33 33 
The capacities respectively given in these two columns are determined by independent 
methods ; and it must be admitted, if we consider the numerous observations necessary 
for any one determination, that the concurrence of these numbers is truly surprising, 
and affords a sufficient guarantee of the accuracy of the method employed for the deter- 
mination of the volumes of gases in these experiments. It is necessary, however, to 
observe that the previous description is exactly applicable only to the ultimate form 
which this apparatus assumed with the various modifications suggested by use. In my 
earlier experiments the apparatus employed differed in various details from that just 
described; it was, however, constructed on perfectly similar principles — namely, the 
measurement of a determinate volume of gas by means of a pipette, and the estimation 
of the volumes of gases at 0°C. and 760 millims. from the observation of the pressure 
and temperature at which the same gases occupy a known space. It does not appear to 
me necessary to trouble the reader with a description of this apparatus, which differed 
from that just described rather in regard to convenience than precision, the difference in 
this latter respect, if any, being in no way sufficient to affect the general result. 
The pipette was placed on a table, being separated from the aspirator by an interval 
of about 8 or 10 inches; in this interval the experiment to which the electrized gas 
was submitted was made. When the gas was passed through a liquid, small glass bulbs 
were employed of the kind delineated in Plate LII. fig. 7. In bulb a the gas is 
delivered through a capillary tube so as to pass in minute bubbles. It is hardly 
necessary to observe that the level of the liquid in the bulb was so adjusted at the com- 
