Brunonian or Particle Movements. 1'?1 



surface tension and of the Brunonian movements are exclucied, 

 we mav make a rough estimate or guess by the eye. The amount 

 and rapiditv of movement vary considerably, but I think we may 

 estimate that among the slow moving particles of gamboge which 

 have been moving without any stoppage for three months a 

 particle makes sufficient movement in two seconds to raise itself 

 its own length against gravity. This may be little more than a 

 guess, but I don't think it is very far wrong, though measured 

 horizontallv and not vertically. To be on the safe side let us 

 say three seconds. That is to say, it would raise itself through 

 20 times its own length in 1 minute, 1200 times its own length in 

 an hour, 28,800 times in a day, and 2,592,000 in three months; 

 and they have not stopped yet ! These are forces and move- 

 ments of very great power and significance. Two thoughts 

 suggest themseh'es as inferences, and with these I conclude. 

 The one is that they plav a very important part in nature. 

 Particles of matter of deleterious nature fall or are blown or 

 otherwise carried into water. They move about meeting the 

 dissolved oxygen till they are oxidised and destroyed. And, on 

 the other hand, bubbles of air perform Brunonian movements in 

 water as I have observed but have not had time to dwell on. 

 These carry with them oxidising and cleansing power. 



The other thought is this : — How excellent an object lesson 

 a glance at these movements would be to pupils who find great 

 difficulty in mastering the Kinetic Theory of matter, which can 

 be shown to exist by electrical means. i 



That there is enormous energv in the action of surface films 

 has been made apparent by these few illustrations. Theoreti- 

 cally they may form some notion that everything in nature is 

 moving, but a glance at a slide in a microscope showing these 

 Brunonian movements would give an impression that would prove 

 indelible. And now we may ask what is rest? and where is rest? 

 Flammarion has shown, and his observations have been 

 confirmed — probably anticipated — that this solid earth moves in 

 a tolerably li\-ely manner through some six or eight inches up 

 and down in a wave running round the world in twenty-four hours, 

 corresponding to the motions of the tides. Minute particles 

 move, as we have seen. The world trembles incessantly not 

 only with motions due to secular cooling which sometimes reach 



