186 F. Leininger: Relation of Electric Charges transported 
for the direction of deflexion of the galvanometer was the 
same as in the preliminary experiments. Similarly was 
confirmed the assumption regarding the weakening of the 
positive current by the withdrawal of the canal rays. 
If the current is led through the front coil, the tube, and 
thence through tke back. coil to earth, a deflexion a is 
obtained, which may be regarded as proportional to the 
difference of the currents ; thus a first equation is obtained 
ee 
in which C is a constant, J the main current, and J’ the main 
current as weakened by the loss of the rays. If the back 
coil be now entirely cut out, a deflexion @’ proportional to 
the main current is obtained, and hence a second equation 

a Ore), 
Dividing, we get 
R aa 
Tea pies ge 
which gives the ratio of the cathode or canal rays to the 
exciting current. The sensitiveness of the Wiedemann 
galvanometer with the front coil alone in use was 3°2x 10-7 
ampere. 
In the following Tables I-IV. are given, besides the results 
of Method I., those of Method II., and they show very good 
agreement with them. Of course, Method II. is not so con- 
venient to use nor so general as Method I., and is mainly 
troublesome on account of the great length of high-potential 
conductor leading to the distant galvanometer. For this 
reason I discarded it in the later investigations ; its main 
object was to confirm my theory regarding the formation 
of the cathode and canal rays as parts of the exciting current. 
Absorption of Rays by the Gas. 
A not inconsiderable, effect on the results is produced by 
the absorption of the rays in the gas-filled space. Unfortu- 
nately, I found it impossible to establish a definite law of 
absorption. Nevertheless, [ was able torepresent the variation 
of absorption by means of curves. It may also be mentioned 
that the absorption experiments were never undertaken 
directly after exhaustion, but after some time, when the 
gaseous contents had to some extent reached a steady state. 
The experiments in question were carried out by placing the 
collecting electrode AH at varying distances from the neigh- 
bouring net-electrode, and observing the values for the rays 
at the lowest possible pressures. It was also necessary to see 

