
The Motion of Radium in the Electric Field. 303 
“¢S-exponential numbers.’’ That, however, these two classes 
are coincident is now easily seen; and, further, all the pro- 
positions proved by Whitehead* for either class of exponential 
numbers hold equally for the whole class of transfinite 
cardinal numbers. In fact that equations (7) and (8) have 
been already proved, and it is also evident that, if 
1<d<24, b>a, c=, 
then 
e?=—P. 
The exponential numbers have not, then, shown a behaviour 
different in any respect to the other transfinite cardinal 
numbers ; and consequently no indication is to be found in 
addition, multiplication, or in at least many cases of ex- 
ponentiation, of a characteristic of these numbers. In 
particular, no contradiction has been found in supposing 
SP acattl +. olla! oid eigind Wee 
because 
ae Ni =, N=N, x=, SIS; 
we cannot, however, yet assert the equation (9). Some 
investigations on this important question will be given 
subsequently. 
Little Close, Yateley, Haunts. 
December 23rd, 1903. 


XXXII. On the Motion of Radium in the Electric Field. 
By J. Jory, D.Se., FRS.T 
LIGHT disk, delicately suspended, and coated upon the 
one side with a few milligrammes of radium bromide 
of high activity, exhibits, when an electrified body is brought 
near to it, motions very different from what would be observed 
in the case of an inactive substance. The usual sequence of 
attraction, electrification, and repulsion are replaced by the 
following effects. The electrified body, whether positive or 
negative in sign, repels the suspended body if brought up to it 
on the side coated with radium, but attracts it if presented at 
the naked side. 
Before attempting an explanation I will describe the expe- 
riment which first gave rise to this observation. 
Two thin microscope cover-glasses about 12 mms. in 
diameter, are attached at the extremities of a glass fibre 
* Amer. Journ. of Math, vol. xxiv. (1902) pp. 393, 394. 
+ Communicated by the Author. 
Y2 
a 
