188 FRAGMENTS OF SCIENCE. 



a dog or a cat ought to be as capable of education as 

 a man. These predetermined internal relations are 

 independent of the experiences of the individual. The 

 human brain is the ' organised register of infinitely 

 numerous experiences received during the evolution 

 of life, or rather during the evolution of that series of 

 organisms through which the human organism has been 

 reached. The effects of the most uniform and frequent 

 of these experiences have been successively bequeathed, 

 principal and interest, and have slowly mounted 

 to that high intelligence which lies latent in the brain 

 of the infant. Thus it happens that the European in- 

 herits from twenty to thirty cubic inches more of brain 

 than the Papuan. Thus it happens that faculties, as 

 of music, which scarcely exist in some inferior races, 

 become congenital in superior ones. Thus it happens 

 that out of savages unable to count up to the number 

 ef their fingers, and speaking a language containing 

 nly nouns and verbs, arise at length our Newtons and 

 Shakespeares.' 



At the outset of this Address it was stated that 

 physical theories which lie beyond experience are de- 

 rived by a process of abstraction from experience. It 

 is instructive to note from this point of view the suc- 

 cessive introduction of new conceptions. The idea 

 of the attraction of gravitation was preceded by the 

 observation of the attraction of iron by a magnet, and 

 of light bodies by rubbed amber. The polarity of 

 magnetism and electricity also appealed to the senses. 

 It thus became the substratum of the conception that 

 atoms and molecules are endowed with attractive and 

 repellent poles, by the play of which definite forms of 

 crystalline architecture are produced. Thus molecu- 



