240 FRAGMENTS OF SCIENCE. 



weigh, in my estimation, all the formal learning ex- 

 pended by Mr. Martineau in those disquisitions on 

 Force, where he treats the physicist as a conjuror, 

 and speaks so wittily of atomic polarity. In fact, 

 without this notion of polarity this 'drawing* and 

 'driving' this attraction and repulsion, we stand as 

 stupidly dumb before the phenomena of Crystallisation 

 as a Bushman before the phenomena of the Solar 

 System. The genesis and growth of the notion I have 

 endeavoured to make clear in my third Lecture on 

 Light, and in the article on ' Matter and Force ' pub- 

 lished in this volume. 



Our further course is here foreshadowed. A Sunday 

 or two ago I stood under an oak planted by Sir John 

 Moore, the hero of Corunna. On the ground near the 

 tree little oaklets were successfully fighting for life 

 with the surrounding vegetation. The acorns had 

 dropped into the friendly soil, and this was the result 

 of their interaction. What is the acorn? what the 

 earth ? and what the sun, without whose heat and 

 light the tree could not become a tree, however rich 

 the soil, and however healthy the seed ? I answer for 

 myself as before all ' matter.' And the heat and 

 light which here play so potent a part are acknow- 

 ledged to be motions of matter. By taking something 

 much lower down in the vegetable kingdom than the 

 oak, we might approach much more nearly to the case 

 of crystallisation already discussed ; but this is not now 

 necessary. 



If, instead of conceding the sufficiency of matter 

 here, Mr. Martineau should fly to the hypothesis of a 

 vegetative soul, all the questions before asked in relation 

 to the snow-star become pertinent. I would invite 

 him to go over them one by one, and consider what 

 replies he will make to them. He may reloit by 



