46 



ON THE PROPERTIES OP MATTEE, 



instances, ought, perhaps, to be contemplated as modifications of gravi- 

 tation. 



Upon these particular attractions, or modes of attraction, including 

 homogeneous attraction, or the attraction of aggregation, heterogeneous 

 attraction, or the attraction of capillary bodies, elective attraction, and 

 those of magnetism and electricity, each of which is replete with phaeno- 

 mena of a most interesting and curious nature, I intended to have touched 

 in the present lecture, but our limited hour is so nearly expired, that we 

 must postpone the consideration of them as a study for our next meeting. 

 Yet it is not possible to close the observations which have now been sub- 

 mitted, without testifying our gratitude to the memory of that transcendent 

 genius whom the providence of the adorable Architect of the universe at 

 length gave to mankind six thousand years after its creation, to unravel 

 its irregular confusion, and reduce the apparent intricacy of its laws to that 

 sublime and comprehensive simphcity which is the peerless proof of its 

 divine original. 



It has been said, that the discovery of the universal law which binds the 

 pebble to the earth, and the planets to the sun, which connects stars with 

 stars, and operates through infinity, was the result of accident. Nothing 

 can be more untrue, or derogatory to the great discoverer himself. The 

 earliest studies of Newton were the harbinger of his future fame ; his mighty 

 mind, that comprehended every thing, was alive to every thing ; the little 

 and the great were equally the subjects of his restless researches : and his 

 attention to the fall of the apple was a mere link in the boundless chain of 

 thought, with which he had already been long labouring to measure the 

 phjenomena of the universe. 



Grounded, beyond all his contemporaries, in the sure principles of mathe- 

 matics, it was at the age of twenty-two that he first applied the sterling 

 treasure he had collected to a solution of the system of the world. The 

 descent of heavy bodies, which he perceived nearly the same on the summit 

 of the loftiest mountains and on the lowest surface of the earth, suggested 

 to him the idea that gravity might possibly extend to the moon ; and that, 

 combined with some projectile motion, it might be the cause of the moon*s 

 elliptic orbit round the earth : a suggestion in which he was instantly con- 

 firmed by' observing, that all bodies in their fall describe curves of some 

 modification or other. And he further conceived, that if the moon were 

 retained in her orbit by her gravity towards the earth, the planets must 

 also in all probability be retained in their several orbits by their gravity 

 towards the sun. 



To verify this sublime conjecture, it was necessary to ascertain two 

 new and elaborate positions : to determine the law of the progressive 

 diminution of gravity, and to develope the cause of the curves or ellipses 

 of faUing bodies. Both these desiderata he accomplished by a series of 

 reasonings and calculations equally ingenious in their origin and demon- 

 strative in their result ; and ascertained the truth of his principles by apply- 

 ing them, practically and alternately, to the phsenomena of the heavens, 

 and to a variety of terrestrial bodies. 



The bold and beautiful theorem being at length arrived at, and unequivo- 

 cally established — a theorem equally applicable to the minutest corpuscles, 

 and the hugest aggregations of matter, — that all the particles of matter 

 attract each other directly as their mass, and inversely as the square of 

 their distance, he at once beheld the cause of those perturbations of motion 

 to which the heavenly bodies are neci^ssarily and so perpetually subject ; it 



