Form and Color in Nature. 237 



now seems to me to be true concerning the matters before 

 me.) 



These light waves in the ether correspond with the slower 

 sound waves in the air, which we perceive by means of the 

 ear. And as these sound waves differ in length and rapidity, 

 thus producing the effect which we recognize as high and 

 low tones, light waves also differ in length and rapidity, and 

 thus produce the effects which we recognize as the several 

 colors. This can be illustrated by the division of the light 

 ray through the interposition of a prism, thus producing the 

 spectrum. 



With this crude explanation of our terms as a foundation, 

 let us try to progress systematically. 



We divide matter, possibly somewhat arbitrarily, into two 

 classes, which we call, respectively, the organic and the inor- 

 ganic. We place at the bottom the inorganic, and raise upon 

 it our ladder of life. 



This inorganic matter we subdivide into various classes in 

 various ways : according to its mechanical situation, so to 

 speak, as solid, liquid or gaseous ; according to its chemical 

 constitution, as metallic or otherwise copper, sulphur, oxy- 

 gen ; or, again, according to its composition or supposed ori- 

 gin in a crude sense, as mineral, etc. To inorganic matter in 

 all its forms we attach the relation of color. We perceive 

 such matter by light, either transmitted or reflected. In 

 either case the light has had impressed upon it a certain 

 character which causes in us the sensation of color. If we 

 see a beam of clear light through a translucent substance, 

 such as glass, or a membrane, it either appears clear to us, or 

 we have an impression of color, caused by the fact that cer- 

 tain waves are allowed to pass freely, while others are inter- 

 cepted. If we look upon an object upon which clear light 

 strikes, it either appears colorless, or we nave an impression of 

 color, because certain waves are absorbed, or pass into the ob- 

 ject, and others are reflected, or thrown back upon the eye. 

 And according as the surface upon which the light falls ig 

 rough, or smooth, or polished, according as it may be crossed 

 by fine lines, or may be delicately laminated, will the color 

 vary. And all conceivable changes may be rung upon the 

 colors which appear. 



And so as to form. What form is not to be found in the 

 inorganic world? Omitting the gases and the liquids, the 

 boundaries of which may be roughly considered as formed 

 by the solid bodies against which they flow, in the solid 



