The significance for us of Chladni's experiment will emerge still more clearly if we modify it in the following way. Instead of directly setting the plate with the powder into vibration by stroking it with the bow, we produce a corresponding movement on a second plate and let it be transmitted to the other by resonance. For this purpose the two plates must be acoustically tuned to each other and placed not too far apart. Let us imagine, further, that the whole experiment was arranged - as it well might be - in such a way that the second plate was hidden from a spectator, who also lacked the faculty of hearing. This gives us a picture of the situation in which we find ourselves whenever the higher kinds of ether by way of a tone-activity inaudible to our physical ear, cause shapeless matter to assume regularly ordered form.