302 Mr. S. T. Preston on the Kinetic Theory of Gravitation. 



5. When the two surfaces (or two molecules) are pushed 

 up closer to each other, then the energy of the gravific medium 

 directed against the remote sides of the molecules prevails 

 more and more, since the mutual sheltering-power of the 

 molecules increases in an enormously rapid ratio as contact is 

 neared, and so the unbalanced energy of the gravific medium 

 directed with full force against the remote sides of the opposed 

 molecules at length outweighs the action of the intercepted 

 aether particles, and the two molecules are propelled together 

 (or unite). 



6. We may allude to a few examples serving to illustrate 

 the application of the above principles. Supposing we take 

 the common case of the ignition of a gas jet. Then when the 

 gas is turned on, the molecules of gas and air mingle with 

 each other and are known to be exchanging motion and re- 

 bounding from each other, and yet they do not unite. Ac- 

 cording to the above principles the molecules, as they approach 

 each other in their encounters, are kept apart by the forcible 

 vibrations (which the molecules are known to possess *) which, 

 through the increments of velocity imparted to the particles 

 of the intervening aether, produce a repulsion in the manner 

 described, as soon as the molecules in their encounters have 

 approached nearly within range of the mean path of the aether 

 particles. When a flame is applied to the jet, the rapidly 

 moving gaseous molecules of which the flame consists naturally 

 produce a disturbance, jostling some of the molecules of the 

 mixture of gas and air against each other, so that the neutral 

 point is passed, whereby the molecules are brought into such 

 proximity that their mutual sheltering action causes the 

 gravific medium to impinge with full energy upon their re- 

 mote sides, thus urging the molecules together (producing 

 combination). The molecules are thrown into forcible vibra- 

 tion by the shock of approach, and become luminous through 

 the energy of the waves thus generated by them in the sur- 

 rounding aether. These vibrations of the compound molecules 

 after combination naturally cause the forcible rebound of any 

 other molecules that happen to be in their proximity, the 

 disturbance thus set up sufficing to effect the successive 

 (practically instantaneous) combination of the entire jet of 

 gas. The same considerations of course apply to the practi- 

 cally instantaneous combination (explosion) of a mixture (in 

 definite proportions) of gas and air, by an initial disturbance 



* The molecules of matter in the gaseous state are known to possess, 

 in addition to the translatory motion peculiar to that state, a vibratory 

 motion, in virtue of which the molecules generate waves of regular periods 

 iu the aether (these periods having in many cases been measured by the 

 spectroscope). 



