190 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1909. 
and that the forces which hold atoms and molecules together, the 
properties which differentiate one kind of matter from another, all 
have their origin in the electrical forces exerted by positive and 
negative units of electricity, grouped together in different ways in 
the atoms of the different elements. 
As it would seem that the units of positive and negative electricity 
are of very different sizes, we must regard matter as a mixture con- 
taining systems of very different types, one type corresponding to 
the small corpuscle, the other to the large positive unit. 
Since the energy associated with a given charge is greater the 
smaller the body on which the charge is concentrated, the energy 
stored up in the negative corpuscles will be far greater than that 
stored up by the positive. The amount of energy which is stored 
up in ordinary matter in the form of the electrostatic potential 
energy of its corpuscles is, I think, not generally realized. All sub- 
stances give out corpuscles, so that we may assume that each atom of 
a substance contains at least one corpuscle. From the size and the 
charge on the corpuscle, both of which are known, we find that 
each corpuscle has 810-7 ergs of energy; this is on the supposition 
that the usual expressions for the energy of a charged body hold 
when, as in the case of a corpuscle, the charge is reduced to one unit. 
Now, in 1 gram of hydrogen there are about 6 10** atoms, so if there 
is only one corpuscle in each atom the energy due to the corpuscles 
in a gram of hydrogen would be 48X10" ergs, or 11X10° calories. 
This is more than seven times the heat developed by 1 gram of 
radium, or than that developed by the burning of 5 tons of coal. 
Thus we see that even ordinary matter contains enormous stores of 
energy ; this energy is fortunately kept fast bound by the corpuscles; 
if at any time an appreciable fraction were to get free the earth 
would explode and become a gaseous nebula. 
The matter of which I have been speaking so far is the material 
which builds up the earth, the sun, and the stars, the matter studied 
by the chemist, and which he can represent by a formula; this matter 
occupies, however, but an insignificant fraction of the universe, it 
forms but minute islands in the great ocean of the ether, the sub- 
stance with which the whole universe is filled. 
The ether is not a fantastic creation of the speculative philosopher ; 
it is as essential to us as the air we breathe. For we must remember 
that we on this earth are not living on our own resources; we are 
dependent from minute to minute upon what we are getting from 
the sun, and the gifts of the sun are conveyed to us by the ether. 
It is to the sun that we owe not merely night and day, spring time 
and harvest, but it is the energy of the sun, stored up in coal, in 
waterfalls, in food, that practically does all the work of the world. 
