70 THE SUN. 



where they fell. The shot would fall in one place, the 

 wheat in another, the sand in another, the chaff in 

 another, and the feathers anywhere nowhere ; but none 

 of them in the straight direction in which they were 

 originally tossed. All would be deviated ; and if you 

 marked the places of each sort, you would find them all 

 arranged in a certain order that of their relative light- 

 ness in a line on the ground, oblique to the line of their 

 projection. You would have separated and assorted 

 them, and formed a spectrum, so to speak, on the 

 ground; or a picture of what had taken place in the 

 process ; which would in effect have been the perfor- 

 mance of a mechanical analysis of the contents of your 

 basket. 



(30.) Bearing always in mind that it is an illustration 

 of a series of facts, not a theoretical explanation of a 

 natural process, which is here intended ; I will now pro- 

 ceed to observe that the analogy of this case to that of 

 the prismatic analysis of a sunbeam may be pursued still 

 further. If the original contents of the basket had been 

 all of one material, such as sand, consisting of a mixture 

 of particles of every gradation of coarseness and fineness ; 

 from small pebbles down to impalpable dust ; the trace 

 upon the ground, the sand spectrum, however long, 

 would be uninterrupted : the coarsest particles lying at 

 one end; the finest at the other; and every intermediate 

 size in every intermediate place. On the other hand, in 

 the case first supposed, and supposing the shot to differ 

 ////.-/ se in respect of si/e within certain limits ; the wheat 

 grains again within certain other ; the sand within other ; 



