40 MR. J. SMITH ON THE ORIGIN OF COLOUR 



Inquiry into the cause of Red, 



62. Had we begun to inquire first of all into the nature 

 of red, our researches would have made slower progress 

 even than they have made. It was by observing shadow 

 to be always so closely connected with the colours blue 

 and green that it became necessary to assume that colour 

 was produced by intervals of light and no-light, vibrating 

 at greater intervals than science teaches. It is difficult to 

 see shadow in the usual acceptation of the term in con- 

 nection with red. Whether we look at the ever varying 

 and gorgeous phenomena of the atmosphere, or at the 

 phenomena produced by refracting media, there is little 

 indication of shadow to be seen. At the setting of the 

 sun many of the rays of the lower limb of the sun are 

 intercepted by the earth, and by the density of the atmo- 

 sphere; and those rays which do reach us direct are re- 

 duced to parallelism ; there is little crossing in comparison 

 with the light of noon. Of course, since fewer rays reach 

 the eye there will be fewer vibrations, less intensity of 

 light ; but this of itself cannot produce colour unless there 

 is also a negative element present, and as this negative 

 element is not discoverable, there is nothing to point out 

 to the intellect that there must be vibrations or pulsa- 

 tions. It might be an uninterrupted flow of light of a 

 different physical character from the ordinary daylight; 

 in fact it might be a homogeneous light compared to the 

 light of day, and might be produced by refraction, or by 

 the absorption of other rays differently constituted from 

 it. 



63. In a fog at noon the sun is often seen of a deep red, 

 with its intensity of light so reduced as to be looked at 

 without inconvenience. I have often remarked on these 

 occasions that it appeared as if one were looking along a 

 red tunnel. The rays were evidently not crossing each 



