188 Mr. G. Johnstone Stoneij [Feb. 6, 



at all, nor even a molecular motion, althougli some of these are 

 secomlary. The only motions that until in recent times any man 

 could ascertain to be motion were the coarser forms of secondary 

 motion, and even still every motion that our senses are competent to 

 perceive to be motion has a very considerable thing that is moved, 

 namely, vast aggregations of subsidiary motions, of kinds which 

 science can show to be present, which we can conceive as motions, but 

 which we are unable to perceive except under forms so disguised that 

 they seem stationary. Until the discoveries of science were made, 

 masses of molecular motions, such as clubs, boats, stones, grains of 

 dust, &c., were mistaken by everybody for objects that might be 

 brought to absolute rest. This is the only class of objects that 

 any one ever felt or saw in motion, and so there grew up the sup- 

 2)osition that wherever there is motion there is something moving 

 which might be brought to rest. This conclusion, however, went beyond 

 ^hat the experience really warranted. The conclusion it warrants 

 is that wherever we men, with certain limited senses, cdiU. perceive that 

 there is motion by the special senses that we happen to possess, 

 whether unassisted or with the best aid we can obtain from micro- 

 scopes or other appliances, there is always something moving. This 

 more guarded statement is perfectly correct ; for since a sufficient 

 scientilic investigation became possible, the very important discovery 

 has been made that in all the cases covered by the correct statement, 

 there is a vast accumulation of subsidiary motions being drifted along. 

 Anything else -which any one supposes to be present, is really not 

 what he knows to exist, but what he imagines. 



Experiments consist of Motions. 



Every experiment man can make consists altogether of motions. 

 A chemist pours one of his solutions upon another. This bringing of 

 them together is a rough secondary motion. This is followed by 

 another motion, the mixing of the two solutions till the molecules get 

 into such close apposition that they can act on each other. The 

 next stage is again motion, when atoms of the one are exchanged for 

 atoms of the other, and new compounds are formed. So also when 

 in theii" new positions the motions of which the atoms consist, or with 

 which they twine amongst one another, are subjected by their new 

 neighbours to new constraints and new influences, and the motions 

 become altered — when perhaps a new colour appears, betraying the 

 fact that a periodic time has changed. In fact, in every part of the 

 process, nothing but motions has ever been traced. 



Take another example. We magnetise a piece of steel and alter 

 some of its internal motions, yet how completely has this changed 

 some of its dynamical relations to several other bodies of the 

 universe ! So when we electrify a conductor. Here wo have altered 

 motions, probably motions in the surrounding dielectric, and we have 

 by doing so profoundly changed the relations of the system to the 

 rest of the universe. So again, when wc spin a gyroscope contained 



