Sxcrion III, 1902 [79 ] Trans. R. S. C. 
VIII.— The Existence of Bodies smaller than Atoms. 
By E. Ruruerrorp, M.A., D.Sc 
Macdonald Professor of Physics, McGill University, Montreal. 
(Read May 27, 1902.) 
During the last few years considerable evidence has been obtained 
of the production, under various conditions, of bodies which behave 
as if their mass was only a small fraction of the mass of the chemical 
atom of hydrogen. As far as we know at present, these minute 
particles are always associated with a negative electric charge. For 
this reason they have been termed “electrons.” In whatever way 
they are produced, they always have the same charge and this charge 
is probably the same as that carried by the hydrogen ion in the 
electrolysis of water. 
A brief historical account will be given of the growth of our 
knowledge of this subject, which seems likely in the near future to 
profoundly modify our ideas of the constitution of matter. 
Faraday showed that when a current passed through a conducting 
solution, the amount of matter deposited or given off at the electrodes 
depended only on the quantity of electricity which had passed through 
the solution. For different solutions, the amounts of matter depos- 
ited for unit quantity of electricity are chemically equivalent to each 
other. It is now generally accepted that the current is carried 
through the solution by means of charged carriers or ions. In an 
electric field the negative ions travel through the solution to the 
positive electrode, and the positive ions to the negative. 
The weight W of hydrogen given off for a passage of Q coulombs 
of electricity is given by 
We. Ge where z = 10-+ is the weight of hydrogen 
given off for a passage of one electromagnetic unit of electricity. 
Let e — charge on an ion. 
m — mass of each ion. 
n — number of ions of hydrogen in a weight W. 
Then Wim 
Q = ne: 
We therefore have © — A EN CRE 
m W Z 
1 The abstract of an address before Section III. of the Society, introducing 
a discussion on the evidence of existence of bodies smaller than atoms. 
Experiments illustrating points of the theory were kindly shown to the 
meeting by Dr. J. Maclennan, of Toronto University. 

