INTRODUCTION. 35 



whether those who have contributed most effectually to the advancement ( 

 of the sciences, have rigidly adhered to Bacon's rules. And, in gen- > 

 eral, such a rigid adherence is unnecessary ; because so much assistance 5 

 can, in general, be derived from what knowledge has been already ac- 

 quired, that a rigid natural historical detail of all the phenomena becomes 

 unnecessary. It was only in the infancy of science that such details 

 were requisite. Boyle often draws them up in his inquiries into the 

 cause of various phenomena, and his investigations were of considerable 

 use in forwarding those branches of science which he cultivated. Bacon 

 also was mistaken in conceiving that, by investigation, mankind may be- 

 come acquainted with the essences of the powers and qualities residing in 

 bodies. So far as science has hitherto advanced, no one essence has 

 been discovered, either as to matter or as to any of its more extensive 

 modifications. Thus we are still in doubt whether heat and electricity 

 be qualities or substances. Yet we have discovered many important 

 properties or laws, by means of which heat and electricity, whether 

 properties or substances, are regulated. And from this knowledge, 

 probably, we derive as much advantage as could be obtained from a 

 complete knowledge of their essence. 



By experiment or observation all the new facts in every science are 

 acquired. By the application of mathematical reasoning to these facts, 

 they are reduced to the requisite simplicity, and the general orinciples 

 which regulate every particular science determined. 



