189 
that the current of the influence-machine remained constant 
during each series of observations. In the accompanying 
curves (figs. 3 to 8) the ray currents are plotted as ordinates, 
and the distances of the collecting electrode as abscisse. 
From the curves it will .be seen that the canal rays are 
absorbed much more strongly than the cathode rays, especially 
if we consider the fact that the cathode rays have really to 
traverse a longer path, since, as is generally accepted 
nowadays*, the canal rays arise in the first layer of the 
cathode light, while the cathode rays have to traverse the 
entire space between cathode and anode, and this in our 
by Cathode and Canal Rays to Exciting Current. 







TaBLeE III. 
Cathode rays in rarefied air. Second kind of net-electrodes. 
| 
| Value of / baer a 
Potential Value of 100 cathode rays | 100 x Canoe Says 
in cathode rays x wiansato a1 current 
100 x ————_++ | corrected for 
| volts. current corrected for pia shidn ence 
absorption by net. a 2 Rees 
| nd reflexion. 
| 
about 500 58 tts 15°7 
1000 12-2 | 23°6 32°7 
1600 16:1—174 31:4—33'5 44:2—46°5 
1800 16°6—17°9 32°1—34:5 44-6—48 
2000 18°3—18°9 35°3—36°4 49 —50°6 
2200 18:'8—19-1 36°3—36'9 50°5—51°3 
2400— 2600 19°3—20 37° 2—38'6 51-7—53'6 
| 2800 20 —21 38°7—40°5 53°8—56'3 
3000—3400 | 21-2—21°6 40°9—41°7 56:8—57°9 
3600 21°6—22-4 41-7—43°2 57°9—60 / 
4000 | I= oe | 42-8—44-4 59'5—61°6 | 
5000 23°4—25:1 | 45°1—48-4 62°7— 67:3 
eesl00 | | 25-4 | 49-1 68-2 
5500 ) 26°6—28'2 51:2--54°5 T11—T5‘7 
| 6000 | 29 —31-05 56 —59°9 77 8—83-2 
7000 | 316—31°8 60°9—61°3 84°7—85'2 | 
| | | 
case amounts to 6°5 cms. 

The absorption diminishes with 
decreasing pressure for both kinds of rays, but more rapidly 
for cathode than for canal rays. To this widely different 
degree of absorption of the rays is perhaps to be ascribed the 
difference in their values, especially as with low pressures, 
for which the absorption of the canal rays is no longer so 
marked, the values for the canal rays approach those for the 
cathode rays. On the other hand, under high pressures, 
when the absorption of the cathode rays becomes of more 
* K. Goldstein, Wied. Azz. lxiv. p. 38 (1898). 
