1 8 Matter and Motion. 



rivers glide, the ocean swells, the air 

 presses, &c. 



2d. That which does not extend to 

 sensible distances. Such is found to ob- 

 tain in the minute particles of which 

 bodies are composed, attracting each oth- 

 er at or extremely near the point of con- 

 tact, with forces often much superior to 

 that of gravity, but which at any distance 

 decrease much faster than the power of 

 gravity. This power a late ingenious 

 author calls the attraction of cohesion, 

 as being that by which the atoms or in- 

 sensible particles of bodies are united into 

 sensible masses. 



The laws of motion, percussion, &c* 

 in sensible bodies, under various circum- 

 stances, as falling, projected, &c. do not 

 reach those more recluse intestine mo- 

 tions in the component particles of the 

 same bodies, on which depend the chan- 

 ges in the texture, colour, properties,. 

 &c. of bodies. So that our philosophy, 

 if it were only founded on the principle 

 of gravitation, and even carried as far as 

 this would kad us, would still be very 

 deficient. But, besides the common law* 

 of sensible masses, the minute parts they 



