1030 Dynamic Theory. 



tion from one molecular space to another, and communicated from the 

 spaces in the metal or other hard parts of the receiving telephone to 

 the spaces in the air, and thence to the ear, &c. It is nothing against 

 this view if this movement of the ether carries with it a greater or less 

 movement of the ponderable matter, the wood of the case, the air, the 

 ear drum, &c. , with which it is so intimately associated. A pretty 

 good illustration of the manner in which I conceive the ether to be as- 

 sociated with ponderable matter may be got by filling a tooth brush 

 with water. If turned over on its back the water will stand amongst 

 the bristles to their full height, and it is easy to see how a jar commu- 

 nicated to the water would affect the bristles as well, and vice versa. 



According to this hypothesis, then, sound depends upon a peculiar 

 jostle or thrust of more or less condensed ether of a consistency only 

 found in association with ponderable matter. This motion may be com- 

 municated to it, and commonty is, by the motion of the ponderable mat- 

 ter it belongs to; and it may be synchronous with vibrations of such 

 matter, or it may outrun and become independent of them, going at a 

 rate and to a distance not possible to vibrations of the ponderable body; 

 for example (I should say), as in the case of sounds conveyed by the 

 earth; or it may arise, as in the experiments mentioned above, as the 

 sequel of current electricity, such current being periodically and sud- 

 denly arrested in part, and its influence on the ether in the magnet, and 

 its field, being reduced to the ejaculatory motion which results in sound. 

 It is in accordance with well-known laws of mechanics that we maj r 

 conceive the ether confined in the intermolecular spaces of ponderable 

 bodies to be subject to reactions against the impact of force, different 

 from those of free or interplanetary ether. If you take a pine stick 

 one inch square and one foot long, and stand it on one end, it will 

 easily bear the weight of a man placed on its top. But if you make 

 the stick 50 feet high, supporting the top with guy lines to prevent fall- 

 ing, it will bear scarcely any weight without springing to one side in 

 the middle; "buckle," as it is called. But if its "buckling" be pre- 

 vented by means of numerous guys, it will sustain the weight of a man 

 the same as the shorter piece. If blows be substituted for weights in 

 the experiment, corresponding effects will be observed. And so we 

 may conceive that when the ether confined in the intermolecular spaces 

 of ponderables receives a thrust, it has less chance to buckle than where 

 it is not thus supported. This consideration coupled with that of an in- 

 creased density in the intermolecular ether, accounts for the greater wave 

 length of sounds in such bodies as steel, copper, water, &c. , without 

 the necessity of including the movement of the ponderable particles 

 themselves, when the finest microscopic observations fail to discover 

 any such movement. 



