CHEMISTRY AND PHYSICS. oe 
placement, for gravity must reside in the ether. But whenever work is done, 
energy is transformed or transferred. The energy of mass motion in the rising 
ball is gradually transformed to energy of ether motion as gravity, and is not in 
any sense whatever stored in the ball. As gravity energy, it exists in the ether 
and may at once be reconverted into energy of mass motion to return the ball to 
earth; or if the ball find a support at its higher elevation, that energy will per- 
sist as gravity energy. The mere possibility of the ball falling to earth again 
does not give it any quality of energy whatever, any more than the first possi- 
bility of its being tossed into the air made it a possessor of energy. But the 
nature of gravity is so little understood that the foregoing reasoning may be re- 
ceived with some hesitancy. Let us therefore consider another illustration com- 
monly employed in the text-books. 
The heat of fuel is frequently spoken of as ‘‘stored energy ’’ derived from the 
sun at the time the plants were growing. I once heard an intelligent lady state 
that the iridescence of anthracite coal was fossil sunshine. Let us consider the 
relationship of the facts as we best know them, and we will find no room for the 
subterfuge of ‘‘ potential energy.’’? The energy of carbon atoms vibrating as such, 
and of oxygen atoms vibrating as such, is greater than that of these elements 
vibrating together as carbon dioxide. Therefore, in order to maintain the vibra- 
tions of carbon and oxygen separately, some energy must be taken up as trans- 
formed from some other source, it matters not from what source derived. Usually 
that source is sunshine. The sunshine falling upon the green chloroplasts of liv- 
ing leaves enables them to separate the absorbed carbon dioxide into its con- 
stituents of carbon and oxygen, because the additional necessary energy is thus 
furnished. But that additional energy utilized is now no longer energy of sun- 
light, but it is energy of chemism; and in no proper sense can it be looked upon 
as stored sunlight any more than the resulting products of carbon and oxygen 
may be regarded as stored carbon dioxide, or the lumber in a lumber-yard as stored 
houses. In after time, when the wood or coal is again burned, that is, when the 
carbon again unites with ogygen, the surplus of chemical energy necessary to the 
carbon atoms and the oxygen atoms as such, over that which exists in their con- 
stitution as carbon dioxide, is transformed mostly to heat, some of it to light or 
electricity possibly, and is but another transformation. A conspicuous absurdity 
of the text-books is to speak of the energy of the sunshine as all stored in the car- 
bon or carbon compounds formed in plants from the carbon dioxide taken from 
the air. As we have seen, the oxygen, separated, plays as important a part in the 
processes as the carbon. Then why not say the solar energy was stored in the 
oxygen as well as in the carbon separated? When carbon and oxygen unite in 
combustion, why is it not said that the oxygen furnished its quota of stored solar 
energy ? 
Let us bear closely in mind the relationship of all the phenomena concerned, 
and ‘‘ potential energy’’ will become an obsolete term, ‘‘stored energy ’’ will drop 
from the vocabulary of physical science, and we will read there only and ever in 
their stead ‘‘ transformed energy.’’ 
