Popular scientific lectures

to the present day, to explain all physical events mechanically. Not to mention e

nt, since they dissolve and destroy many other bodies more solid than they: while if we regard its effects, we see that when light is accumulated, say by concave mirrors, it has the property of combustion just as fire has, that is to say, it disunites the parts

e of excluded perpetual motion into the th

so when the influence of heat or of electricity is employed. But can phenomena of heat or electricity be thought of as due t

sure as a circumstance that produces motion is very familiar to us from daily experience. All changes which the individual personally produces in his environment, or humanity brings about by means of the arts in the world, are effected through the instrumentality of motions. Almost of necessity, therefore, motion appears to us as the most important physical factor. Moreover, mechanical properties may be discovered

undt represents in his excellent treatise On the Physical Axioms is probably shared by

causes are mo

cause lies outside

the direction of the straight

t of every c

involves an equa

t is equivalen

les of mechanics. But when they are set up as axioms of physics, their e

nnihilated and something else created in its place, which is not to be reconciled with our idea of the identity of the object observed and of the indestructibility of matter. But we have only to remember that the Eleatics encountered difficulties of exactly the same sort in motion. Can we not also imagine that a thing is destroyed in one place and in another an exactly similar thing created? After all, do we really know more why a body leaves one place and a

. It happens, in fact, to men who give themselves up to this view for many years, that the world of sense from whic

an effective part in popular lectures, but in the workshop of the serious inquirer it has discharged scarcely the least function. What has really been achieved in mechanical physics is either the elucidation of physical processes by more fa