180 Brunonian or Particle Movements. 



familiar more or less for over a century, yet Sir William Ramsay 

 (another eminent Englishman hailing from Scotland) not so 

 long ago discovered argon, neon, krypton, xenon, which had 

 escaped notice in spite of thousands of previous analyses ! 



That there is enormous energy latent in surface films has 

 been amply established by these few illustrations, but let us take 

 one more to bring it home. The movements in these prepara- 

 tions have been going on for months without ceasing. Compare 

 them with a clock. In an eight-day clock we pull up weights, 

 say eight pounds through five feet, and thus do 40 foot-pounds of 

 work, by which the clock goes for a week. In twelve or thirteen 

 weeks we expend about 500 foot-pounds of work, or about a 

 quarter of a ton lifted through one foot. But in these prepara- 

 tions which I show you the movement, self-driven, has been 

 going on for twelve or thirteen weeks without previous winding 

 up. For three months the action arid reaction of the films of 

 solid and liquid in contact, and of the films of liquid of different 

 density, have kept up these Brunonian movements. During 

 that time the energy exerted must have been equal to lifting the 

 particle through millions of times its own height against gravity. 

 This illustration gives a rough idea of the magnitude of the forces 

 operating, as we may put it, in a drop of water. For exact 

 metrical estimates of these forces one must go to the works of 

 Quincke and his pupils and other chemists and physicists. For 

 this purpose we must consult German scientific publications in- 

 accessible in the Queen of the iSouth. To the excellence of 

 your library I have already testified, yet one cannot help observ- 

 ing that if it is a counsel of perfection to expect to find the 

 records of the great foreign workers, or even of their British 

 co-workers in the journals of the Royal, Linnean, Chemical, and 

 Geological Societies — which one certainly would find in the 

 libraries of Continental societies of a similar standing to this — 

 that even those the society does possess might be made more 

 accessible at very slight trouble. The volumes of "Nature" 

 are not accessible because not bound, and the series of the 

 British Association reports are incomplete, though these are 

 granted free to approved societies, in which select number this 

 society is included. 



But though exact metrical measurements of the force of 



