ODORS AND LIFE. 185 



cessary aid of oxygen in the atmosphere, proves, too, that 

 odors are in no respect comparable to light or heat, which 

 one may regard in an abstract way, in the immaterial and 

 ethereal space which is the region of their motion, as 

 proper forces, and acting from a distance. Odors, to be 

 perceived, must be taken up by oxygen, and borne by it to 

 the organ of smell. In a word, odor is the odoriferous 

 particle itself, while light is not the light-giving body. 



Does oxygen exert a chemical influence on those atoms 

 of which it robs odorous substances ? We do not know, 

 neither do we know of what kind is the action which oc- 

 curs on the contact of odor with the olfactory nerve, 

 whether the phenomenon is a mere mechanical agitation, 

 or whether some chemical decomposition takes place in the 

 case. At any rate, it is allowable to reason from the ob- 

 served facts that smell and taste are two senses peculiarly 

 distinct from the others, as well with respect to the ob- 

 ject of sensation as to the ideas which the mind derives 

 from the sensation itself. Sight, touch, and hearing, in a 

 manner physical senses, furnish us the ideas of external 

 forms, harmonies, and motions. They introduce us to the 

 conception of the beautiful, and are true fellow-laborers 

 with the intellect. Taste and smell are rather chemic 

 senses, as Nickles calls them. They come into action only 

 upon contact, and awake in us only such sensations as life 

 and mind gain no profit from. While the former are the 

 spring of the highest functions, the latter are of use only 

 for the performance of acts of nutrition. 



The learned and capable author * of a book on odors, 

 published within a few years, fancies, however, that he can 

 establish a kind of aesthetics of odors, more or less resem- 

 bling that of tones. He has investigated olfactory harmo- 

 nies, hoping to find in them the elements of a sort of music. 

 " Odors," he says, " seem to affect the olfactory nerves in 



1 Piesse, on " Odors, Perfumes, and Cosmetics." 

 9 



