7O 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 

 inter se in respect of size within certain limits ; the wheat 

 grains again within certain other; the sand within other; 



