General Objects and Principles. 9 



losophy. He adopted the Baconian principle of 

 conducting all inquiries by experiment alone. He 

 effected much in the analysing of bodies, and the 

 examination into the principles of which they 

 were composed. He is by many said to have 

 invented that curious and useful instrument, the 

 air-pump ; and his experiments on the nature of 

 air have laid the foundation for ah 1 the modern 

 doctrines concerning it. His discoveries on light 

 and colours were an excellent introduction to the 

 grand theory of Newton on that subject, and, 

 possibly, served as the basis or foundation, of 

 them. In short, there was scarcely a topic of 

 natural philosophy to which he did not bend his 

 attention, and scarcely one which he did not 

 more or less improve : but still the facts educed 

 were insulated. 



Such was the state of philosophy when Newton 

 appeared. He reduced, into one grand scheme, 

 all the scattered discoveries of his predecessors. 

 He explained the motions of the heavenly bodies 

 on a principle entirely new, and established that 

 beautiful planetary theory which is now univer- 

 sally received. He developed, with mathematical 

 precision, all the phenomena of light and colours, 

 the nature of vision, and the use of optical glasses 

 and instruments, which last he greatly improved. 

 In short, he gave body and consistency to natural 

 philosophy, and made it, what it never was be- 

 fore, a coherent system of truth, illustrated and 

 proved by experiment. 



