ON GOETHE'S SCIENTIFIC RESEAECHES. 58 



intricate actions and reactions, though governed by 

 strict laws, can scarcely be taken in at a glance. To 

 him the impressions of sense are not an irrefragable 

 authority; he examines what claim they have to be 

 trusted ; he asks whether things which they pronounce 

 alike are really alike, and whether things which they 

 pronounce different are really different ; and often finds 

 that he must answer, no ! The result of such examination, 

 as at present understood, is that the organs of sense do 

 indeed give us information about external effects pro- 

 duced on them, but convey those effects to our conscious- 

 ness in a totally different form, so that the character of a 

 sensuous perception depends not so much on the proper- 

 ties of the object perceived as on those of the organ by 

 which we receive the information. All that the optic 

 nerve conveys to us, it conveys under the form of a sensa- 

 tion of light, whether it be the rays of the sun, or a blow 

 in the eye, or an electric current passing through it. 

 Again, the auditory nerve translates everything into phe- 

 nomena of sound, the nerves of the skin into sensations of 

 temperature or touch. The same electric current whose 

 existence is indicated by the optic nerve as a flash of 

 light, or by the organ of taste as an acid flavour, excites 

 in the nerves of the skin the sensation of burning. The 

 same ray of sunshine, which is called light when it falls 

 on the eye, we call heat when it falls on the skin. But 

 on the other hand, in spite of their different effects upon 

 our organisation, the daylight wliich enters through our 

 windows, and the heat radiated by an iron stove, do not 

 in reality differ more or less from each other than the 

 red and blue constituents of light. In fact, just as in the 

 Undulatory Theory, the red rays are distinguished from 

 the blue rays only by their longer period of vibration, 

 and their smaller refrangibility, so the dark heat rays of 

 the stove have a still longer period and still smaller re- 



