BOOK IV. 



INDUCTIVE INVESTIGATION. 



CHAPTEK xviii. 



OBSERVATION. 



ALL knowledge proceeds originally from experience. 

 Using the name in a wide sense we may say that ex- 

 perience comprehends all that we feel, externally or 

 internally the aggregate of the impressions which we 

 receive through the various apertures of perception the 

 aggregate consequently of what is in the mind, except so 

 far as some portions of knowledge may be the reasoned 

 equivalents of other portions. As the word experience 

 implies a , we go through much in life, and the impres- 

 sions gathered intentionaUy or unintentionally afford the 

 materials from which the active powers of the mind 

 evolve science. 



No small part of the experience actually employed in 

 science is acquired without any distinct purpose. We 

 cannot use the eyes without gathering some facts which 

 may prove useful. Every great branch of science has 

 generally taken its first rise from an accidental observa- 

 tion. Erasmus Bartholinus thus first discovered double 

 refraction in Iceland spar ; Galvani noticed the twitching 

 of a frog's leg ; Oken was struck by the form of a 



a Max Miiller's 'Lectures on Language/ vol. ii. p. 73. 

 VOL. II. B 



