362 Mr. S. Tolver Preston on Method 



fectly certain (as has been proved again and again in science) 

 that no truth is safe from being disguised by spiritualistic 

 theories of this character, in the face of which reason loses its 

 influence, and legitimate proof its power of appeal. 



It does not seem to be adequately realized that there can be 

 nothing mysterious in the mere scale of the parts of the matter 

 that forms the aether, that it is as easy to reason of matter of 

 one scale as of another, that smallness of moving particles (so 

 as to allow number in unit of volume) is the essential condition 

 for the concentration of the greatest possible amount of energy 

 in a given volume of the aether, that it may be proved defi- 

 nitely beforehand that this energy, if it existed, would cer- 

 tainly be concealed in its normal state. All this should excite 

 interest in the case. But what do we find in fact ? The sub- 

 ject is scarcely discussed ; and even care w^ould not seem to be 

 taken to inquire what we should expect to find if these things 

 were true*. The mystery due to the notion of " force," which 

 precludes all hope of any addition to knowledge, has rendered 

 the subject repulsive. 



May we not at least attempt what preliminary steps can be 

 made towards an advance by dropping the spiritualistic 

 assumption about " force." In the first place, as before re- 

 marked, we must regard the aether as of molecular consti- 

 tution, or all means of accounting for its properties would be 

 excluded. The most important observed fact in regard to the 

 aether is perhaps the entire absence of any measurable 

 resistance opposed by it to the passage of bodies (such as the 



* No doubt the preconceived idea would naturally be tbat, in order for 

 a motive agent to contain a store of motion adapted to produce such an 

 effect as an explosion of gunpowder (for example), something boisterous 

 and appealing to the senses would be required, not the thin impalpable 

 aether whose very presence eludes direct detection by the senses. But on 

 the question being examined into, exactly the reverse of all this found to 

 be true. For it may be proved, with mathematical certainty, that the 

 greater the intensity of a store of motion in the material agent, the less 

 would it appeal to the senses. For the greater the velocity of the particles 

 of a material agent, the less is the resistance opposed by the agent to the 

 passage of masses through it, or the more impalpable does the agent 

 become. This one fact, as a definite mechanical truth (independently of 

 all questions as to its possible application in nature), ought surely to be 

 enough to excite inquiry and arouse a rational interest. The vague and 

 utterly unpractical way in which this great physical agent (the aether) is 

 commonly treated would indicate an absence of realization of the physical 

 qualities that we should expect to find in the aether if it were a great dy- 

 namic agent of enormous practical importance in the everyday operations 

 of nature. If it were merely attempted (as an ordinary engineering pro- 

 blem) to reason out beforehand what qualities a material agent ought to 

 possess in order to be adapted as a general source of motion, then the qua- 

 lities the aether appears to have would be seen to be precisely of the kind 

 required. 



