ae UTAH ACADEMY OF SCIENCES 121 
find the smallest particle which defied further division, 
so efforts were made to find the smallest charge of elec- 
tricity which could exist as a separate and distinct entity. 
One value for this electrical charge was found in the 
conduction of an electrical current thru a sclution of 
sulphuric acid. In this experiment hydrogen and oxygen 
are set free and the mass of hydrogen and oxygen is 
always directly proportional to the quantity of elec- 
tricity passed thru the solution. Knowing the mass of 
hydrogen liberated and the quantity of electricity used, 
it was possible to calculate the electrical charge carried 
by one hydrogen ion. .The value obtained was 3 x 10” 
electrostatic units. This value was in error because the 
number of atoms in a cubic centimeter of gas was not so 
accurately known. The name electron was given to this 
charge by Dr. Johnston Stoney in 1891. 
In the conduction of electricity thru gases, bodies 
were found which caused this same charge, some were 
charged positively as the hydrogen ion and others were 
vharged negatively. While the negative charge had the 
same value as the charge on a hydrogen ion in solution 
the negative electron was found to have a mass much 
less than the mass of the hydrogen ion. 
Other sources of negative electrons were soon found. 
We now know that all hot bodies emit negative electrons. 
The incandescent filament in our electric lamps is shoot- 
ing out a veritable hailstorm of negative electrons. Rad- 
ium and other radioactive substances are also sending 
out a shower of negative electrons. We get an emission 
of these bodies by illuminating metals with light. When 
violet light is allowed to shine on a piece of zine it 
becomes charged with positive electricity showing that 
negative electricity has been removed. The negative 
electricity is removed thru the expulsion of negative elec- 
trons. In all these cases the charge on the negative 
electrons is the same and the mass of them is found to be 
saz of a hydrogen atom. When this important fact was 
fixed it became necessary for us to revise our notions 
about the atom being the smallest indivisible particle of 
matter. syria 
.. Now having found a particle of mass much smaller 
