238 FEAGMENTS OF SCIENCE. 



The last paragraph of this argument is forcibly and 

 ably stated. On it I am willing to try conclusions with 

 Mr. Martineau. I may say, in passing, that I share 

 his contempt for the picturesque interpretation of 

 nature, if accuracy of vision be thereby impaired. But 

 the term Vorstellungs-fahigkeit, as used by me, means 

 the power of definite mental presentation, of attaching 

 to words the corresponding objects of thought, and of 

 seeing these in their proper relations, without the 

 interior haze and soft penumbra! borders which the 

 theologian loves. To this mode of ' interpreting 

 nature ' I shall to the best of my ability now adhere. 



Neither of us, I trust, will be afraid or ashamed to 

 begin at the alphabet of this question. Our first 

 effort must be to understand each other, and this 

 mutual understanding can only be ensured by begin- 

 ning low down. Physically speaking, however, we 

 need not go below the sea-level. Let us then travel 

 in company to the Caribbean Sea, and halt upon the 

 heated water. What is that sea, and what is the sun 

 that heats it ? Answering for myself, I say that they 

 are both matter. I fill a glass with the sea-water and 

 expose it on the deck of the vessel ; after some time the 

 liquid has all disappeared, and left a solid residue of 

 salt in the glass behind. We have mobility, invisi- 

 bility apparent annihilation. In virtue of 



The glad and secret aid 

 The sun unto the ocean paid, 



the water has taken to itself wings and flown off as 

 vapour. From the whole surface of the Caribbean Sea 

 such vapour is rising : and now we must follow it not 

 upon our legs, however, nor in a ship, nor even in a 

 balloon, but by the mind's eye in other words, by that 

 power of Vorstellung which Mr. Martineau knows so well, 



