Physics
In proportion as physical science studies this universe, so it recognises more and more clearly that its most general phenomenon is vibration, a periodical movement, which propagates itself in waves succeeding each other at regular intervals.
We have all noticed the effect produced by drops of rain falling on water which the absence of wind leaves perfectly tranquil. Each drop forms a circle, but the causes of perturbation of an aqueous surface are infinite; the dip of an insect, the leap of a fish, all ceaselessly cause new circles, which follow each other, become wider, and finally lose themselves in each other under our eyes; the water is apparently a prey to shivering fits; this is a type of the vibrations whose percussions are felt by the whole world. We are all, body and soul, subject to the law of vibrations, each sense recognises its power by means of sensations whose various kinds are apprehended by physical science, by the calculation of the number of vibrations which, in a given time, affect differently each of our organs of sensation. Science records the number of vibrations which denote to our skin the exact degree of the external temperature, she counts the millions of vibrations which enable our eyes to see definite colours in the space of a second, and the thousands of vibrations which enable our ears to hear, in the same space of time, well defined sounds.
Thus physical science explains a general phenomenon which exerts its influence, indubitably, on all men since there have been men on earth.