OF NATURAL PHILOSOPHY. 245 



the ultimate atoms of solid or even fluid bodies, 

 and to produce all the phenomena which they 

 exhibit in their crystallized state, either when acting 

 on each other, or on light, heat, &c. It is not diffi- 

 cult, if we give the reins to imagination, to conceive 

 how attractive and repulsive atoms, bound together 

 by some unknown tie, may form little machines or 

 compound particles, which shall have many of the 

 properties which we refer to polarity ; and accord- 

 ingly many ingenious suppositions have been made 

 to that effect : but in the actual state of science it 

 is certainly safest to wave these hypotheses, without 

 however absolutely rejecting them, and regard the 

 polarity of matter as one of the ultimate phenomena 

 to which the analysis of nature leads us, and of 

 which it is our business fully to investigate the laws, 

 before we endeavour to ascertain its causes, or trace 

 the mechanism by which it is produced. 



(268.) The mutual attractions and repulsions of the 

 particles of matter, then, and their polarity, whether 

 regarded as an original or a derivative property, are 

 the forces which, acting with great energy, and 

 within very confined limits, we must look to as the 

 principles on which the intimate constitution of all 

 bodies and many 'of their mutual actions depend. 

 These are what are understood by the general term 

 of molecular forces. Molecular attraction has been 

 attempted to be confounded by some with the 

 general attraction of gravity, which all matter exerts 

 on all other matter ; but this idea is refuted by the 

 plainest facts. 



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