UNDULATORVY MOVEMENTS AS AFFECTING OUR SENSES. 155 
sharp. It is like a single man meeting a phalanx. But if the finger comes in con- 
tact with a surface and finds even resistance at all points then we say it is smooth. 
That is like phalanx meeting phalanx. In like manner we may explain dullness, 
keenness, roughness, hardness, etc.—all properties which are learned by the 
sense of touch. 
Now, having gone thus far, let us tablulate our conclusions. Matter exists 
as masses, molecules, atoms and ether. ‘These are all continually in motion. 
Matter which produces wave motion must move in one or other of two phases— 
(x) parallel to or (2) transverse to the line of direction of wave. This much es- 
tablished, let us say : 
I. Masses vibrate: 
(a) There is undulatory movement in az; 
(b) Elements move parallel to line of direction of wave; 
(c) Rate of vibration extending, for aught we know, from o to o per 
second; 
(d) Within the limits 16-40000 per second the ear is affected and we hear 
sound ; 
(e) Either side of these limits is silence so far as man is concerned. 
Il. Molecules vibrate: 
(a) There is undulatory movement in e¢her; 
(b) Elements move transverse to line of direction of wave; 
(c) Rate of vibration extending from o to o per second. 
(d) Within the limits 400 trillions to 700 trillions per second the eye is 
affected and we can see light. 
(e) Either side of these limits is darkness so far as man is concerned. 
(f) Other senses affected in the same way are the nose, the skin and prob- 
ably the muscles, but by what rates of motion we do not know. 
Molecules vibrate : 
(a) In contact with the tongue—Taste ; 
(b) In contact with the hand—Touch. 
Now we hinted just now that possibly molecular vibration may result in 
thought. If this be true, and there is such a thing as sympathetic vibration 
among molecules as there is between musical strings, pendulums, etc., then is it 
strange that two persons should think the same thought at the same moment? 
Doubtless you have all had such experience. You have been surprised to hear a 
friend in your company speak of something which at the same moment was occu- 
-pying your personal thought. Be it understood we do not say that thought can 
thus be explained, but the theory seems plausible to say the least of it. 
To go a little further in this theorizing, if the so-called ether does pervade all 
space, and if vibrations or undulations once started in this ether never cease, and 
if the human organs of us limited beings take cognizance of occurrences around 
us when undulations within certain limits fall upon our senses, then an omnipo- 
tent, omnipresent being with unlimited powers could experience absolutely and 
