NOVEMBEE 18, 1898.] 



SCIENCE. 



683 



in fact, seals itself quite up again. The 

 marvel is that the projectile gets so far after 

 the first breakdown. It could not do so if 

 the main part of its motion were not swift, 

 indicating a very steep pressure gradient. 

 At all events, the time soon arrives (5-10 

 minutes) when the elastic resistance of the 

 strained colloid ahead of the projectile is in 

 excess of the remnant of hydrostatic pres- 

 sure behind it, and the projectile stops. It 

 would gradually stop even without the re- 

 cementation of the triturated channel, but 

 the fact that the antics begin all over again 

 with the next projectile is proof (were it 

 needed) that the column has actually re- 

 sumed continuity. It again gives evidence 

 of definite rigidity. 



Other things I would like to add, but I 

 have alreadj' trespassed too far. 



The ether.— Now, whenever one finds out 

 anything about jelly — something of an order 

 just a little above the kitchen I mean — one 

 has the right to traipse in the footprints of 

 well-known great thinkers and approach 

 the ether. I am not given to denying my- 

 self, so I shall have my ether, which, just 

 like the jelly, is to be solid or liquid under 

 like conditions, as I please. Nobody ever 

 caught such an ether before (though it has 

 been fished for), which, to repeat, shall be 

 either continuous and rigid or discontinu- 

 ous, triturated, virtually rigid, as the condi- 

 tions warrant. Note that since it must be 

 elastic* it may as well be solid, without in- 

 voking essentially new conditions. 



Beyond this my ether is to have no re- 

 spectable properties at all, except that if 

 broken it seals itself up again, as all ethers 

 do, particularly under pressure, and that it 

 resists breakdown as this becomes more 

 rapid. It is to be nearly incompressible, 

 brittle, and in the first instance (by no 

 means the last) free from inertia. Such 



* It is unfortunate that all ethers must be elastic. 

 This really introduces the -whole of our molecular 

 machinery over again and indicates nothing ultimate. 



an ether can transmit stress instantaneously 

 like a stick, or, better, like that imponder- 

 able instrument with which people poke fun 

 at us. The ether cannot of itself vibrate. 

 Though incompressible, it may become vir- 

 tually so by enclosing triturated regions, 

 particularly in the pressure of matter. 



The body. — With these admissions, I will 

 examine, for a moment, the relations of 

 this ether to a physical body, regarded as a 

 grouping of ultimate particles fixed rela- 

 tively to each other. I shall use this body 

 chiefly to produce the triturated regions, 

 with a view to dropping* it from the con- 

 siderations altogether, if it can be made to 

 appear non-essential. 



Let there be given a region free from 

 force. Let a body be imbedded in the solid 

 (continuous) ether, permeating the region 

 and permeating the body intramolecular ly 

 as well. In the first instance, inertia as a 

 physical property is to be attributed neither 

 to the body nor to the region. 



Let the body be moved by an impulse from 

 without. Immediately there will be dis- 

 continuous ether capable of transmitting 

 hydrostatic pressure behind the body, or, 

 better, behind each ultimate particle of the 

 body, while the sheared continuous ether 

 pervades in front of it, in the direction 

 of motion. 



Now, suppose that the trituration in 

 question is a marked occurrence, accom- 

 panied, therefore, by increase of volume. 

 There must then be a simultaneous mani- 

 festation of hydrostatic pressure in the 

 triturated region greater, as the surround- 

 ing solid ether is more rigid. 



Regions of triturated ether. — Now, consider 

 the triturated region (however produced) 

 by itself, supposing no material ultimate 

 particles present therein. f 



*The remarks in the American Journal refer to this 

 body in place, in the manner set forth by the above 

 text. 



fl have also carried out these ideas, keeping the 



