Page:Popular Science Monthly Volume 6.djvu/158

146 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 occurs 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 observed facts that smell and taste are two senses peculiarly distinct from the others, as well with respect to the object 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 resembling that of tones. He has investigated olfactory harmonies, hoping to find in them the elements of a sort of music. "Odors," he says, "seem to affect the olfactory nerves in certain definite degrees, as sounds act on the auditory nerves. There is, so to speak, an octave of smells, as there is an octave of tones; some perfumes accord, like the notes of an instrument. Thus almond, vanilla, heliotrope, and clematis, harmonize perfectly, each of them producing almost the same impression in a different degree. On the other hand, we have citron, lemon, orange peel, and verbena, forming a similarly associated octave of odors, in a higher key. The analogy is completed by those odors which we call half-scents, such as the rose, with rose-geranium for its semitone; 'petit-grain' and neroli, followed by orange-flower. With the aid of flowers already known, by mixing them in fixed proportions, we can obtain the perfume of almost all flowers." In accordance with these fancies, Piesse has formed gamuts of odors, parallel with musical gamuts, and exhibiting concords of scents at the same time with those that produce discords. As a painter blends his tints, the perfumer should blend his fragrances; and Piesse maintains he can only gain that object by following the laws of harmony and contrast in odors. This theory is certainly quite ingenious, and deserves attention, but it is open to serious objections. If the harmony of colors and of sounds exists, it is because optics and acoustics are exact sciences, and harmony in this case is reduced to numerical relations,