(Tr?) 
0 
U Bels 
centimetres per second under 1 cm. of mercury pressure; in this 
formula s is the density, whereas v) is dependent only on the 
mechanical friction. 
Let us suppose that in a capillary electrometer the ohmic resis- 
tance in the circuit is reduced to zero, then in our formula (1) the 
constant C is determined only by the mechanical friction in the 
capillary‘). We will call the constant, when this is assumed, &. 
For a given value of y*—y=v the formula can then be put ?) 
in the form 
If u represents the displacement of the mercury meniscus for 
1 cm. change of mercury pressure, then 
du 
JT 0 ; 
hence also 
i AOP SEMA LP 
The constant k is, as appears from formula (2), determined only 
by the magnitude of the displacement of the meniscus with a given 
change of pressure and the mechanical friction in the capillary; 
can be calculated from uw and v°). 
Moreover & can be calculated in an entirely different manner 
viz: from 1. the constants of the normal curves, recorded without 
and with resistance purposely inserted in the circuit, 2rd, the 
internal resistance of the capillary electrometer. For & is the con- 
*) Vid. on this point a former paper Lc. 
We remind the reader that y and y* denote the displacements from the zero 
position of the meniscus. In formula (1) we indicated as the cause of these displace- 
ments the change of P. D. between the poles of the capillary electrometer, the 
pressure in the capillary remaining constant. The formula remains unchanged if with 
a constant P. D. the displacements of the meniscus are caused by a change of pressure 
in the capillary. 
*) In calculating * the difference between the friction of the sulphuric acid and of 
the mercury in the inferior part of the capillary has been neglected. It was supposed 
that the friction m the capillary electrometer equalled that in the capillary when 
totally filled with mercury. The error hereby introduced is but small and amounts 
only to a small percentage of the final result, see the more detailed publication. 
