I assume that sound, like odour, is a real substance of unknown and wonderful tenuity, emanating from a body where it has been induced by percussion, and throwing out absolute corpuscles of matter--inter-atomic particles--with a velocity of 1120 feet per second, in vacuo 20,000. The substance which is thus disseminated is a part and parcel of the mass agitated, and if kept under this agitation continuously would, in the course of a certain cycle of time, become thoroughly absorbed by the atmosphere; or, more truly, would pass through the atmosphere to an elevated point of tenuity corresponding to the condition of subdivision that governs its liberation from its parent body. The sounds from vibratory forks, set so as to produce etheric chords, while disseminating their compound tones permeate most thoroughly all substances that come under the range of their atomic bombardment. The clapping of a bell in vacuo liberates these atoms with the same velocity and volume as one in the open air; and were the agitation of the bell kept up continuously for a few millions of centuries, it would thoroughly return to its primitive element. If the chamber were hermetically sealed, and strong enough, the vacuous volume surrounding the bell would be brought to a pressure of many thousands of pounds to the square inch, by the tenuous substance evolved. In my estimation, sound truly defined is the disturbance of atomic equilibrium, rupturing actual atomic corpuscles; and the substance thus liberated must certainly be a certain order of etheric flow. Under these conditions is it unreasonable to suppose that, if this flow were kept up, and the body thus robbed of its element, it would in time disappear entirely? All bodies are formed primitively from this high tenuous ether, animal, vegetable and mineral, and they only return to their high gaseous condition when brought under a state of differential equilibrium.