PREFACE. 



But notwithstanding the true path to science 

 was thus exactly marked out, the old notions ot 

 the schools so strongly possessed people's minds 

 at that time, as not to be eradicated by any new 

 opinions, how rationally soever advanced, until 

 the illustrious Mr. BOYLE, the first who pursued 

 LORD BACON'S plan, began to put experiments in 

 practice with an assiduity equal to his great 

 talents. Next, the ROYAL SOCIETY being esta- 

 blished, the true philosophy began to be the 

 reigning taste of the age, and continues so to this 

 day. 



The immortal SIR ISAAC NEWTON insisted, even 

 in his early years, that it was high time to banish 

 vague conjectures and hypotheses from natural phi- 

 losophy, and to bring that science under an entire 

 subjection to experiments and geometry. He 

 frequently called it the experimental philosophy, so 

 as to express significantly the difference between 

 it and the numberless systems which had aris' a 

 merely out of the conceits of inventive brains : tie 

 one subsisting no longer than the spirit of novell v 

 lasts; the other never failing whilst the nature of 

 things remains unchanged. 



The method of teaching and laying the founda- 

 tion of physics, by public courses of experiments, 

 was first undertaken in this kingdom, I believe, 

 by Dr. JOHN KEILL, and since improved and en- 



