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is a definite amount of force distributed through nature, 
which is invariable in amount, and which we can neither 
add to nor take from, but Avhilst the force in one form dis- 
appears, it reappears in another form. But what do we 
mean by the term force ? The simplest definition of the 
term is that which describes it as something which produces 
or resists motion. When we think of force we think of 
something moving or moved.” 
This definition of the term force would be unexception- 
able, if what is called force, be held simply as indicating 
the properties of the bodies in which it acts, and not as a 
something, or energy, existing by itself, as an entity, apart 
from matter, but as a part of it. Were it merely intended 
to declare, that the sum of the mechanical forces, as gravity, 
inertia, and elasticity, is a constant quantity, just as is that 
of the bodies in which these forces are inherent properties, 
then there would be no grounds for asserting this fact, as 
disclosing a “great new doctrine;” for the indestructible 
nature of matter, and of its properties, were physical truths 
known and taught in our childhood. 
The relations of matter and force — at least as regards the 
mechanical forces — have been set forth in such ample de- 
tail, comprising all known facts, in the elements of physical 
science, that it would seem needless to repeat the facts, of 
the unchangeable nature of the material universe, both as 
to the amount of, and the kind of forces, pertaining to 
matter, but for the enunciation of theories implying such 
changes, wherefore to treat of the conservation of the 
natural forces, and of the disappearance of “ one kind of 
force and reappearance of another kind,” must be held as 
employing unmeaning, or misleading terms. It is not that 
any of the forces themselves can disappear, or be changed 
from one to another kind of force; but that the motions 
generated by them may cease, or be rendered quite uniform 
when the moving forces are exactly balanced, by their 
action in opposite directions, 
